Few inventions in modern times have had as much impact on human life and on the global environment as the automobile. Automobiles and trucks have had a strong influence on the history, economy, and social life of much of the world.

Entire societies, especially those of the industrialized countries, have been restructured around the power of rapid, long-distance movement that the automobile confers on individuals and around the flexible distribution of goods made possible by trucks. Automobiles have given great freedom of movement to their owners, but encourage sprawl (i.e., straggling, low-density urban development). Sprawl degrades landscapes and produces traffic congestion, which tends to immobilize the automobiles that make sprawl itself possible. Furthermore, the dependence of cars and trucks (and thus of the economies based on these machines) on petroleum imposes strong forces on global politics, moving industrial societies such as the United States (which consumes approximately 25% of the world’s oil) to be deeply concerned with the power struggles of the Persian Gulf, where approximately 70% of the world’s oil reserves are located.

The automobile is also a significant health hazard, both directly and indirectly. According to the United Nations, over a million people (both vehicle occupants and pedestrians) die every year on the world’s roads; the United States alone loses over 40, 000 lives annually to car crashes. Meanwhile, automobile exhausts are the largest single source of air pollution in the United States. Air pollution from the manufacture and operation of automobiles contributes importantly to crop damage, acid rain, destruction of the ozone layer, lung disease, and early death by a variety of health problems. Sixteen percent of the world’s annual greenhouse-gas production comes from automobiles; greenhouse gasses contribute to global climate change, which may disrupt food production and flood coasts and low islands worldwide.

The first automobiles, constructed in the late nineteenth century, were essentially horse-drawn carriages with the horses removed and engines installed. After more than a century of development, the modern automobile is a sophisticated system. It offers the mobility and flexibility of use demanded by an enormous variety of lifestyles and industries. Automobiles affect every aspect of society, from the design of our cities to police, ambulance, fire, and utility services to such personal uses as vacation travel, dining, and shopping. Mass production techniques, first developed for the automobile in the early twentieth century, have been adapted for use in nearly every industry, providing for the efficient and inexpensive production of products.

Trucks, especially 18-wheel tractor-trailer trucks, have become the major form of transporting goods across the country, allowing, for example, produce to be quickly transported to markets while still fresh. The use of automotive technology—tractors, combines, pickers, sprayers, and other self-propelled machines—in

agriculture has enabled farmers to increase the quantity, quality, and variety of our foods, albeit at the price of increased soil erosion rates, agricultural dependence on petroleum-derived fuels and fertilizers, and increased runoff pollution. Meanwhile, dozens of industries depend, directly or indirectly, on the automobile. These industries include producers of steel and other metals, plastics, rubber, glass, fabrics, petroleum products, and electronic components.

Structure of the automobile

Thousands of individual parts make up the modern automobile. Much like the human body, these parts are arranged into several semi-independent systems, each with a different function. For example, the human circulatory system comprises the heart, blood vessels, and blood. The automobile contains analogous circulatory systems for coolant fluid (mostly water), for lubricating oil, and for fuel. The engine— the “heart” of the automobile—comprises pistons, cylinders, tubes to deliver fuel to the cylinders, and other components. Each system is necessary for making the automobile run and reducing noise and pollution.

The major systems of an automobile are the engine, fuel system, transmission, electrical system, cooling and lubrication system, and the chassis, which includes the suspension system, braking system, wheels and tires, and the body. These systems will be found in every form of motor vehicle and are designed to interact with and support each other.

Design factors

When an automobile is designed, the arrangement, choice, and type of components depend on various factors. The use of the automobile is one factor. Some cars are required only for local driving; these cars may be capable of achieving good fuel economy on short trips, but they may be less comfortable to drive at high speeds. A sports car, built for speed, will have enhanced steering and handling abilities, but requires a stronger engine, more fuel, and a more sophisticated suspension system. Most automobiles must be flexible enough to perform in every situation and use.

Other factors in the design of automobiles include the requirements for pollution-control components that have been placed on the modern automobile. Safety features are also a factor in the automobile’s design, affecting everything from the braking and steering systems to the materials used to construct the body. The design of the body must incorporate standards of safety, size and weight, aerodynamics or ways to reduce the friction of airflow, and appearance.

The choice of front-wheel drive allows for a smaller, more fuel-efficient car. The arrangement of the engine and its relationship to other automobile systems will be different in a rear-wheel-driven car. Independent suspension for all four wheels improves the automobile’s handling, safety, and comfort, but requires a more complex arrangement. The use of computer technology, the most recently added system to the automobile, requires changes in many of the car’s other systems. Lastly, cost is an important factor in the design of a car. Many features useful for improving the various systems and characteristics of an automobile may make it too costly to produce and too expensive for many people to buy.

The design of an automobile, therefore, is a balance of many factors. Each must be taken into consideration, and compromises among features satisfy as many factors as possible. Yet, for all the variety among automobiles, the basic systems remain essentially the same.

Interaction of systems

Before examining the components of each system, it is useful to understand how the systems interact. The human body is again a good example of the interaction of systems. The heart pumps blood, which feeds the tissues of the body while at the same time helping to remove impurities. The tissues, fed by blood, are able to perform their tasks and often are required to support the action of the heart. Muscle tissue, for example, depends on the availability of oxygen-rich blood from the heart in order to move the body.

The internal combustion engine is the heart of the automobile. The engine produces heat energy from burning fuel and converts that energy into the power to move the different components that will move the car. The engine converts the chemical energy produced by the burning of the fuel into mechanical energy. This energy is used to spin a shaft. The spinning shaft, through the interaction of the transmission and other components, causes the wheels to turn and the car to move. A similar transfer of energy to motion can be seen when bicycling. The up and down motion of the feet and legs is converted to the turning motion of the pedals, which in turn pulls the chain that causes the rear wheel to spin.

The engine requires an electrical system to give it an initial push. The electric starter motor of an automobile provides the force needed to give the engine its initial movement. The battery supplies energy for the engine to use when burning the fuel needed to make it run. The alternator is driven by a belt attached to the engine, recharging the battery so there will be a constant supply of energy. The sensors of the computer control system, which governs many of the processes in an automobile, also require electricity.

The burning of fuel is a hot, noisy process that also produces pollutants in the form of exhaust. This exhaust must be carried away from the engine and away from the automobile. The exhaust system, with its muffler, also acts to reduce the noise produced by the vehicle. Burning fuel in the cylinders produces two other results: friction and extremely high temperatures. In order to protect the parts from being worn down from the friction and from melting with the heat, they must be properly lubricated and cooled. These systems depend on the engine and the electrical system for the power to perform their tasks.

The engine’s power is used to turn the automobile’s wheels. Because the tires are the only parts of the automobile that are actually in contact with the road, they must rest on a system of supports that will carry the weight of the car and respond to conditions of the road surface. At the same time, the driver must be capable of guiding the direction of the automobile. Once an automobile is moving, it will continue to move until the friction of the brake is applied to stop it.

The wheels, suspension, steering, and braking systems are all attached to the car’s chassis, as is the rest of the automobile. The chassis and body, analogous to the skeletal structure in the human body, provide support for all the various systems and components, while also providing safety, comfort, and protection from the elements for the automobile’s passengers.

Engine

The engine operates on internal combustion; that is, the fuel used for its power is burned inside the engine. This burning occurs inside cylinders. Within the cylinder is a piston. When the fuel is burned, it creates an explosive force that causes the piston to move up and down. The piston is attached, via a connecting rod, to a crankshaft, where the up and down movement of the piston converts to a circular motion. When bicycling, the upper part of a person’s leg is akin to the piston. Power from the leg is passed through the pedal in order to turn the crank.

Gasoline is the most common automobile fuel. It is pulled into the cylinder by the vacuum created as the piston moves down through the cylinder. The gasoline is then compressed up into the cylinder by the next movement of the piston. A spark is introduced through a spark plug placed at the end of the cylinder. The spark causes the gasoline to explode, and the explosion drives the piston down again into the cylinder. This movement, called the power stroke, turns the crankshaft. A final movement of the piston upward again forces the exhaust gases, the byproducts of the fuel’s combustion, from the cylinder. These four movements—intake, compression, power, and exhaust—are called strokes. The four-stroke engine is the most common type of automobile engine.

Most automobiles have from four to eight cylinders, although there are also two-cylinder and 12-cylinder automobiles. The cylinders work together in a sequence to turn the crankshaft, so that while one cylinder is in its intake stroke, another is in the compression stroke, and so forth. Generally, the more cylinders, the more smoothly the engine will run. The size of the automobile will affect the number of cylinders the engine uses. Smaller cars generally have the smaller four-cylinder engine. Mid-sized cars will generally require a six-cylinder engine, while larger cars need the power of an eight-cylinder engine.

The number of cylinders, however, is less important to the level of an engine’s power than is its displacement. Displacement is a measure of the total volume of fuel mixture moved by all the pistons working together. The more fuel burned at one time, the more explosive the force, and thus the more powerful given to the engine. Displacement is often expressed as cubic centimeters (cc) or as liters. A smaller engine will displace 1, 200 cc (1.2 L) for 60 horsepower, while a larger engine may displace as much as 4, 000 cc (4 L), generating more than 100 horsepower. Horsepower is the measurement of the engine’s ability to perform work. The size and weight of the car also affect its power. It takes less work to propel a lighter car than a heavier car, even if they have the same engine, just as a horse carrying a single rider can go faster with less effort than a horse drawing a cart.

Fuel system

Gasoline must be properly mixed with air before it can be introduced into the cylinder. The combination of gasoline and air creates a more volatile explosion. The fuel pump draws the gasoline from the gas tank mounted toward the rear of the car. The gasoline is drawn into a carburetor on some cars, while it is fuel-injected on others; both devices mix the gasoline with air (approximately 14 parts of air to one part of gasoline) and spray this mixture as a fine mist into the cylinders. Other parts of the fuel system include the air cleaner, which is a filter to ensure that the air mixed into the fuel is free of impurities, and the intake manifold, which distributes the fuel mixture to the cylinders.

Exhaust system

After the fuel is burned in the pistons, the gases and heat created must be discharged from the cylinder to make room for the next infusion of fuel. The exhaust system is also responsible for reducing the noise caused by the explosion of the fuel.

Exhaust gases are discharged from the cylinder through an exhaust valve. The exhaust gathers in an exhaust manifold before eventually being channeled through the exhaust pipe and muffler and finally out the tailpipe and away from the car. The muffler is constructed with a maze of what are called baffles, specially developed walls that absorb energy, in the form of heat, force, and sound, as the exhaust passes through the muffler.

The burning of fuel creates additional byproducts of hazardous gases—hydrocarbons, carbon monoxide, and nitrogen oxide—which are harmful both to the engine’s components and to the environment. The emission control system of a car is linked to the exhaust system, and functions in two primary ways. The first is to reduce the levels of unburned fuel. This is achieved by returning the exhaust to the fuel-air mixture injected into the cylinders to burn as much of the exhaust as possible. The second method is through a catalytic converter. Fitted before the muffler, the catalytic converter contains precious metals that act as catalysts. That is, they increase the rate of conversion of the harmful gases to less harmful forms.

Cooling system

The automobile uses an additional system to reduce the level of heat created by the engine. The cooling system also maintains the engine at a temperature that will allow it to run most efficiently (or perhaps one should say least inefficiently, given that even the most efficient automobile engine converts only about a third of the energy in gasoline into mechanical work). A liquid-cooled system is most commonly used.

The explosion of fuel in the cylinders can produce temperatures as high as 4, 000°F (2, 204°C); the temperature of exhaust gases, while cooler, still reaches as high as 1, 500°F (816°C). Liquid-cooling systems use water (mixed with an antifreeze that lowers the freezing point and raises the boiling point of water) guided through a series of jackets attached around the engine. As the water solution circulates through the jackets, it absorbs the heat from the engine. It is then pumped to the radiator at the front of the car, which is constructed of many small pipes and thin metal fins. These allow a large surface area to draw the heat from the water solution. A fan attached to the radiator uses the wind created by the movement of the car to cool the water solution further. Temperature sensors in the engine control the operation of the cooling system, so that the engine remains in its optimal temperature range.

Lubrication

Without proper lubrication, the heat and friction created by the rapid movements of the engine’s parts would quickly cause it to fail. The lubrication system of an automobile acts to reduce engine wear caused by the friction of its metal parts, as well as to carry off heat. At the bottom of the engine is the crankcase, which holds a supply of oil. A pump, powered by the engine, carries oil from the crankcase and through a series of passages and holes to all the various parts of the engine. As the oil flows through the engine, it forms a thin layer between the moving parts, so that they do not actually touch. The heated oil drains back into the crankcase, where it cools. The fumes given off by the crankcase are circulated by the PCV (positive crankcase ventilation) and valve back to the cylinders, where they are burned off, further reducing the level of pollution given off by the automobile.

Electrical system

Electricity is used for many parts of the car, from the headlights to the radio, but its chief function is to provide the electrical spark needed to ignite the fuel in the cylinders. This is performed by an electrical system, which comprises a battery, starter motor, alternator, distributor, ignition coil, and ignition switch. As discussed above, the starter motor is necessary for generating the power to carry the engine through its initial movements. Initial voltage is supplied by the battery, which is kept charged by the alternator. The alternator creates electrical current from the movement of the engine, much as windmills and watermills generate current from the movement of air or water.

Turning the key in the ignition switch draws current from the battery. This current, however, is not strong enough to provide spark to the spark plugs, so it is drawn through the ignition coil, which comprises the tight primary winding and the looser secondary winding. The introduction of current between these windings creates a powerful magnetic field. Interrupting the current flow, which happens many times a second, causes the magnetic field to collapse. The collapsing of the magnetic field produces a powerful electrical surge. In this way, the 12-volt current from the battery is converted to the 20, 000 volts needed as spark to ignite the gasoline.

Because there are two or more cylinders, and therefore as many spark plugs, this powerful current must be distributed—by the distributor—to each spark plug in a carefully controlled sequence. This sequence must be timed so that the cylinders and the pistons powering the crankshaft work smoothly together. For this reason, most automobiles manufactured today utilize an electronic ignition, in which a computer precisely controls the timing and distribution of current to the spark plugs.

Transmission

Once the pistons are firing and the crankshaft is spinning, this energy must be converted, or transmitted, to drive the wheels, but the crankshaft spins only within a limited range, usually between 1, 000 to 6, 000 revolutions per minute (rpm), and this is not enough power to cause the wheel to turn when applied directly. The transmission accomplishes the task of bringing the engine’s torque (the amount of twisting force the crankshaft has as it spins) to a range that will turn the wheels. One way to experience the effect of torque is by using two wrenches, one with a short handle and the other with a long handle. It may be difficult to turn a nut with the shorter wrench, but the nut turns much more easily with the longer wrench, because it allows a more powerful twisting force. The transmission has two other functions: allowing reverse movement and braking the engine.

There are two types of transmission: manual and automatic. With a manual transmission, the driver controls the shifting of the gears. In an automatic transmission, as its name implies, gears are engaged automatically. Both types of transmission make use of a clutch, which allows the gears to be engaged and disengaged.

Automobiles generally have at least three forward gears plus a reverse gear, although many manual transmissions have four or even five gears. Each gear provides a different ratio of the number of revolutions per minute (rpms) of the crankshaft (the power input) to the number of revolutions per minute of the output of the transmission, directed to the wheels. For example, in first gear, which is needed to move the automobile from a standstill, the ratio of input to output is 3.5 to one or even higher. The greater the ratio, the more torque will be achieved in the output. Each successively higher gear has a lower input to output ratio. This is because once the automobile is rolling, progressively less torque is needed to maintain its movement. The fourth and fifth gears found on most cars are used when the engine has achieved higher speeds; often called overdrive gears. These gears allow the input to output ratio to sink lower than one to one. In other words, the wheels are spinning faster than the crankshaft. This allows for higher speeds and greater fuel efficiency.

Chassis

The chassis is the framework to which the various parts of the automobile are mounted. The chassis must be strong enough to bear the weight of the car, yet somewhat flexible in order to sustain the shocks and tension caused by turning and road conditions. Attached to the chassis are the wheels and steering assembly, the suspension, the brakes, and the body.

The suspension system enables the automobile to absorb the shocks and variations in the road surface, keeping the automobile stable. Most cars feature independent front suspension, that is, the two wheels in front are supported independently of each other. In this way, if one wheel hits a bump while the other wheel is in a dip, both wheels will maintain contact with the road. This is especially important because steering the automobile is performed with the front wheels. More and more cars also feature independent rear suspension, improving handling and the smoothness of the ride.

The main components of the suspension system are the springs and the shock absorbers. The springs suspend the automobile above the wheel, absorbing the shocks and bumps in the road surface. As the chassis bounces on the springs, the shock absorbers act to dampen, or quiet, the movement of the springs, using tubes and chambers filled with hydraulic fluid.

The steering system is another part of the suspension system. It allows the front wheels to guide the automobile. The steering wheel is attached to the steering column, which in turn is fitted to a gear assembly that allows the circular movement of the steering wheel to be converted to the more linear, or straight, movement of the front wheels. The gear assembly is attached to the front axle by tie rods. The axle is connected to the hubs of the wheels.

Wheels and the tires around them are the only contact the automobile has with the road. Tires are generally made of layers of rubber or synthetic rubber around steel fibers that greatly increase the rubber’s strength and ability to resist puncture. Tires are inflated with air at a level that balances the greatest contact with the road surface with the ability to offer puncture resistance. Proper inflation of the tires will decrease wear on the tires and improve fuel efficiency.

Body

The body of a car is usually composed of steel or aluminum, although fiberglass and plastic are also used. The body is actually a part of the chassis, the whole formed by welding stamped components into a single unit. While the body forms the passenger compartment, offers storage space, and houses the automobile’s systems, it has other important functions as well. Passenger safety is achieved by providing structural support strong enough to withstand the force of an accident. Other parts of the car, such as the front and hood, are designed to crumple in a crash, thereby absorbing much of the impact. A firewall between the engine and the interior of the car protects the passengers in case of an engine fire. Lastly, the body’s shape contributes to reducing the level of wind resistance as the car moves, allowing the driver better handling and improving fuel efficiency.

Hybrids

In the last few decades, several makes of affordable hybrid cars have appeared on the United States and other markets. Hybrid cars burn gasoline in an efficient engine to produce electricity. Power from the

KEY TERMS

Catalyst —Any agent that accelerates a chemical reaction without entering the reaction or being changed by it.

Combustion —A form of oxidation that occurs so rapidly that noticeable heat and light are produced.

Friction —A force caused by the movement of an object through liquid, gas, or against a second object that works to oppose the first object’s movement.

Gear —A wheel arrayed with teeth that mesh with the teeth of a second wheel to move it.

Ratio —A measurement in quantity, size, or speed of the relationship between two or more things.

Shaft —A rod that, when spun, can be used to move other parts of a machine.

Torque —The ability or force needed to turn or twist a shaft or other object.

Voltage —Measured in volts, the amount of electrons moved by an electric current or charge.

batteries is combined with power from the gasoline motor to run an electric motor to move the car. Some energy is also recovered from braking instead of being dissipated entirely as heat. Today’s commercially-available hybrid cars produce about a tenth of the air pollution per mile traveled that is produced by conventional cars of comparable size; they get significantly better mileage as well. U.S. sales of hybrid cars jumped from about 80, 000 in 2004 to over 200, 000 in 2005. Hybrid cars accounted for over 10% of midsize car sales in 2006, and over 20 hybrid models were due on the market as of 2007.

Resources

BOOKS

Black, Edwin. Internal Combustion: How Corporations and Governments Addicted the World to Oil and Derailed the Alternatives. New York: St. Martin’s Press, 2006.

Conley, Robyn. The History of the Automobile. Chanhassen, MN: Child’s World, 2004.

OTHER

International Center for Technology Assessment. “The Real Price of Gasoline” <http://www.icta.org/doc/Real%20Price%20of%20Gasoline.pdf> (accessed October 17, 2006).

U.S. Census Bureau. “2004–2005 Statistical Abstract of the United States” <http://www.census.gov/prod/www/statistical-abstract.html> (accessed October 18, 2006).

M. L. Cohen

The Gale Encyclopedia of Science

Automobile

views updated Jun 11 2018

AUTOMOBILE

AUTOMOBILE. During the first half of the twentieth century, the automobile evolved from a marginal curiosity to the dominant mode of ground transportation in the United States, spawning a vast network of national interstate highways, spurring the postwar suburban sprawl, opening up unprecedented possibilities of mobility for the average Amreican, but also spawning a host of stubborn social ills: air pollution, traffic jams, road rage, and even a major contribution to global climate change.

Origins and Early Development

Although a smattering of inventors on both sides of the Atlantic worked on developing various forms of automotive technology between 1860 and 1890, German and French inventors were well ahead of their American counterparts by the 1890s in development of the gasoline-powered automobile. In Germany, Gottlieb Daimler and his assistant William Maybach had perfected a four-cycle internal-combustion engine by 1885 and had built four experimental vehicles by 1889. Karl Benz built his first

car in 1886 and by 1891 had developed the automobile to the stage of commercial feasibility. In France, Emile Constant Levassor created the basic mechanical arrangement of the modern motorcar in 1891 by placing the engine in front of the chassis, making it possible to accommodate larger, more powerful engines. By 1895, when Levassor drove a car over the 727-mile course of the Paris-Bordeaux-Paris race at the then incredible speed of fifteen miles per hour, automobiles regularly toured the streets of Paris.

The United States lagged well behind. Credit for the first successful American gasoline automobile is generally given to the winners of the Times-Herald race held on Thanksgiving Day 1895: Charles E. Duryea and J. Frank Duryea of Springfield, Mass., bicycle mechanics who built their first car in 1893 after reading a description of the Benz car in Scientific American in 1889. It is now known that several American inventors built experimental gasoline automobiles prior to the Duryeas, but it was the Duryeas who initiated the manufacture of motor vehicles for a commercial market in the United States in 1896. Allowing for changes of name and early failures, thirty American automobile manufacturers produced an estimated 2,500 motor vehicles in 1899, the first year for which the United States Census of Manufactures compiled separate figures for the automobile industry. The most important of these early automobile manufacturers in volume of product was the Pope Manufacturing Company of Hartford, Conn., also the nation's leading bicycle manufacturer.

After these inauspicious beginnings, the United States emerged in the first decade of the twentieth century as the world's leading car culture. The market for motor-cars expanded rapidly as numerous races, tours, and tests demonstrated their strengths, and three transcontinental crossings by automobile in 1903 inaugurated informal long-distance touring by the average driver. The most important organized reliability runs were the Glidden Tours, sponsored annually between 1905 and 1913 by the American Automobile Association. Speed tests and track and road races gave manufacturers publicity for their products and contributed much to the development of automotive technology. Among the early competitions stressing speed, none excited the popular imagination more than the Vanderbilt Cup road races (1904–1916).

Despite a brief but intense reaction between 1900 and 1906 against the arrogance displayed by the owners of automobiles, many of whom sped dangerously through city neighborhoods, kicked up dust on rural roads, and seemed to delight in their ability to spook horses, many Americans displayed great enthusiasm for the motorcar from its introduction. Municipal and state regulations concerning motor vehicles developed slowly, reflected the thinking of the automobile clubs, and typically imposed lighter restrictions than those in European nations. Years before Henry Ford conceived of his universal car for the masses, few people doubted that automobiles were cleaner and safer than the old gray mare. The automobile seemed to fire the imagination of the American people, who provided a large and ready market for the nascent industry's products.

Americans had registered some 458,500 motor vehicles by 1910, making the United States the world's fore-most automobile culture. Responding to an unprecedented seller's market for an expensive item, between 1900 and 1910 automobile manufacturing leaped from one hundred and fiftieth to twenty-first in value of product among American industries and became more important to the national economy than the wagon and carriage industry by all measurable economic criteria.

Automobile Manufacturing

Because the automobile was a combination of relatively standard components already being produced for other uses—stationary and marine gasoline engines, and carriage bodies and wheels, for example—early automobile manufacturers merely assembled available components to supply finished cars. The small amount of capital and the slight technical and managerial expertise needed to enter automobile manufacturing were most commonly diverted from other closely related business activities—especially from machine shops and from the bicycle, carriage, and wagon trades. Assemblers met their capital requirements mainly by shifting the burden to parts makers, distributors, and dealers. Manufacturers typically required 20 percent advance cash deposits on orders, with full payment upon delivery; and the assembly process took well less than the thirty-to ninety-day credit period that parts makers allowed. These propitious conditions attracted some 515 companies into automobile manufacturing by 1908, the year in which Henry Ford introduced the Model T and William C. Durant founded General Motors.

The Association of Licensed Automobile Manufacturers (ALAM) attempted to restrict entry into, and severely limit competition within, the automobile industry. This trade association formed in 1903 to enforce an 1895 patent on the gasoline automobile originally applied for in 1879 by George B. Selden, a Rochester, New York, patent attorney. The ALAM, which tended to emphasize higher-priced models that brought high unit profits, sued the Ford Motor Company and several other unlicensed "independents," who were more committed to the volume production of low-priced cars and who made and sold cars without paying royalties to the association. A 1911 written decision sustained the validity of the Selden patent but declared that Ford and others had not infringed upon it because the patent only covered automobiles with a narrowly defined, outdated engine type. To avoid other patent controversies, the newly formed National Automobile Chamber of Commerce (which became the Automobile Manufacturers Association in 1932 and the Motor Vehicle Manufacturers Association in 1972) instituted a cross-licensing agreement among its members in 1914. This patent-sharing arrangement proved to be an effective antimonopoly measure and prevented companies from using the patent system to develop monopoly power within the industry.

Although the pending Selden suit discouraged high-volume production before 1911, some manufacturers experimented with quantity production techniques from an early date. Ransom E. Olds initiated volume production of a low-priced car, but the surrey-influenced design of his $650, one-cylinder, curved-dash Olds (1901–1906) was soon outmoded. The $600, four-cylinder Ford Model N (1906–1907) deserves credit as the first reliable, powerful, low-priced car. The rugged Ford Model T (1908–1927), remarkably adapted to the wretched rural roads of the day, gained almost immediate popularity and caused Ford's share of the market for new cars to skyrocket to roughly 50 percent by the outbreak of World War I.

Mass production techniques—especially the moving-belt assembly line perfected at the Ford Highland Park, Mich., plant in 1913–1914—progressively reduced the price of the Model T to a low of $290 ($2,998 in 2002 dollars) for the touring car by 1927, placing reliable automobiles within reach of most middle-class Americans. Equally significantly, Ford production methods, when applied to the manufacture of many other items, spurred a shift from an economy of scarcity to one of affluence, created a new class of semiskilled industrial workers and opened new opportunities for remunerative industrial employment to unskilled workers. The five-dollar ($89.95 in 2002 dollars), eight-hour day instituted at Ford in 1914—which roughly doubled wages for a shorter workday—dramatically suggested that mass production necessitated mass consumption and mass leisure.

To compete with the Model T's progressively lower prices, the makers of moderately priced cars followed the lead of the piano industry and began extending installment credit to consumers, lowering a major bar to purchase. More than 110 automobile finance corporations existed by 1921, most notably the General Motors Acceptance Corporation, founded in 1919, and by 1926 time sales accounted for about three-fourths of all automobile sales. By the late 1920s, critics complained that this kind of buying, which became increasingly popular for other types of merchandise, too, was causing an erosion of the values of hard work, thrift, and careful saving sanctified in the Protestant ethic and so central to the socioeconomic milieu of perennial scarcity predicted by the classical economists.

Effect of the Automobile

During the 1920s and 1930s the mass adoption of the automobile in the United States left few facets of everyday life untouched, and the young technology became deeply woven into the fabric of the country's economy, mobility patterns, and culture. As cities became larger and denser, industries increasingly sought cheap land on the urban periphery where they could erect the large, horizontally configured factories that mass production techniques necessitated. Wealthier urbanites, too, dispersed into out-lying suburban areas, closely trailed by retail stores seeking their patronage. Across rural America, larger trading areas hastened the death of the village general store, cut into small local banks' deposits, forced the mail-order houses to open suburban retail stores, and prompted the large-scale reorganization of both retail and wholesale trades, particularly as they fought to stay afloat during the Great Depression. Urban amenities, too, reached into formerly isolated rural areas, most notably in the form of far better medical care and consolidated schools. The Model T, the motor truck, and the motorized tractor also played a role in the reorganization of the agricultural sector as large-scale agribusiness began to replace the traditional family farm.

Large-scale use of automobiles had a tremendous effect on the cities, too. Public health benefited as horses disappeared from cities; but street life became increasingly hazardous, especially for playing children, and automobile accidents became a major cause of deaths and permanent disabilities. Modern city planning and traffic engineering arose to meet growing traffic and parking problems; and attempts to accommodate the motorcar through longer blocks, wider streets, and narrower sidewalks strained municipal budgets even as they undercut the tax base by encouraging residential dispersal. Parents complained that automobiles undercut their authority by moving courtship from the living room into the rumble seat; police complained that getaway cars made it more difficult to catch crooks. Recreational activities changed, too, as the automobile vacation to the seashore or the mountains became institutionalized and as the Sunday golf game or drive became alternatives to church attendance, the family dinner, and a neighborhood stroll.

By the mid-1920s automobile manufacturing ranked first in value of product and third in value of exports among American industries. The automobile industry had become the lifeblood of the petroleum, steel, plate glass, rubber, and lacquer industries, and the rise of many new small businesses, such as service stations and tourist accommodations, depended on the 26.7 million motor vehicles registered in the United States in 1929—one for every 4.5 persons—and the estimated 198 billion miles they traveled. Construction of streets and highways was the second largest item of governmental expenditure during the 1920s, accounting in 1929 alone for over $2.2 billion in road expenditures, financed in part by $849 million in special motor vehicle taxes, $431 million in gasoline taxes, and the steady expansion of the federal-aid road system that began dispersing funds in 1916.

Improvements in Technology

Improved roads and advances in automotive technology ended the Model T era. As the 1920s wore on, consumers came to demand much more than the Model T's low-cost basic transportation. The self-starter, which superseded the hand crank, gained rapid acceptance after 1911. Closed cars increased from 10.3 percent of production in 1919 to 82.8 percent in 1927, making automobiles year-round, all-weather vehicles. Ethyl gasoline, octane-rated fuels, and better crankshaft balancing led to the high-compression engine in the mid-1920s. By then four-wheel brakes, "bal-loon" tires, and wishbone front-wheel suspension provided a smoother, safer ride. Mass-produced cars of all colors became possible after quick-drying Duco lacquer made its debut in the "True Blue" of 1924 Oakland. By the mid-1920s, Chevrolet offered a larger, more powerful, and faster six-cylinder car costing only a few hundred dollars more than a Model T.

Thus, Henry Ford's phenomenally successful market strategy—a single, static model at an ever-decreasing price—became outmoded in the 1920s. In its place emerged the General Motors strategy, pioneered by Alfred P. Sloan, Jr., of blanketing the market with cars in several price ranges, constantly upgrading product through research and testing, and changing models annually. And while Henry Ford ran his company as an extension of his personality, General Motors developed the decentralized, multidivisional structure of the modern industrial corporation, becoming the prototype, widely copied after World War II, of the rational, depersonalized business organization run by a technostructure.

Competition sharpened in the late 1920s as the market approached saturation. Replacement demand outpaced demand from initial owners and multiple-car owners combined in 1927, and in 1929 total production peaked at 5.3 million motor vehicles—not again equaled until 1949. The inadequate income distribution of Coolidge prosperity meant a growing backlog of used cars on dealers' lots, and only about a third of all dealers were making money. A trend toward oligopoly in the automobile industry, observable since 1912, accelerated as economies of scale and the vertical integration of operations became more essential for survival. The number of active automobile manufacturers dropped from 108 to 44 between 1920 and 1929; Ford, General Motors, and Chrysler combined for about 80 percent of the industry's output. The 1930s depression shook out most of the remaining independents. Despite mergers among the independents that survived into the post–World War II period, in the mid-1970s only American Motors (formed from Nash-Kelvinator and Hudson in 1954) survived to challenge Detroit's Big Three. New firms, such as Kaiser-Frazer and Tucker, failed in the postwar industry.

The major innovations in modern automotive technology not yet incorporated by the late 1920s were the all-steel body, the infinitely variable automatic transmission, and drop-frame construction, which placed the passenger compartment between rather than upon the axles, lowering the car's height and center of gravity. Increasingly, since the 1930s, auto executives placed emphasis on styling, which the Chrysler "Airflow" models pioneered in the 1930s and which the 1947 Studebaker exemplified. The automatic transmission, introduced in the 1939 Oldsmobile, had by the 1970s become standard equipment along with power brakes, power steering, radios, and air conditioning. A horsepower race in the 1950s, spurred by the high-compression, overhead-cam, V-8 engine, culminated in the "muscle cars" of the late 1960s.

But mounting consumer demand throughout the 1960s for the economical Volkswagen, a number of Japanese-built compacts, and domestic models such as the Nash Rambler and the Ford Mustang reversed, at least temporarily, the industry trend toward larger, more powerful, and more expensive cars, particularly during the energy crises beginning in 1973 and 1979. The major innovations of the 1980s and 1990s grew out of new computer-aided engineering (CAE), design (CAD), and manufacturing (CAM), which helped manufacturers streamline production, reduce the cost and time required to introduce new models, and lower drag coefficients of new car designs. Engineers also made use of electronic sensors and controls, along with new technologies such as fast-burn/lean-burn engines, turbochargers, and continuously variable transmissions, to improve car and engine performance.

The Post–World War II Industry

Before the mid-1980s, the post–World War II American automobile industry could be considered a technologically stagnant industry, though it progressively refined its product and automated its assembly lines. Neither motorcars nor the methods of manufacturing them changed fundamentally over the next generation. Many of the most promising improvements in the internal-combustion engine—such as the Wankel, the stratified charge, and the split-cycle rotary engines—were pioneered abroad, as were the first significant attempts to depart from traditional assembly-line production. Common Market and Japanese producers steadily encroached upon the dominant American manufacturers, who responded to foreign competition by cutting labor costs—heightening factory regimentation, automating assembly lines, and building overseas subsidiaries. Detroit's share of the world market for cars slipped from about three-fourths in the mid-1950s to little more than a third by the mid-1970s. The market share for American manufacturers began a steady rise in the early 1980s, however, as the Big Three cut their overseas subsidiaries, improved the quality of design and manufacturing, and developed new styles of vehicles, such as the minivan and the sport utility vehicle (SUV), that built on their traditional strengths in the large-car market.

Federal legislation affecting the automobile industry proliferated from the New Deal era on. The National Labor Relations Act of 1935 encouraged the unionization of automobile workers, making the United Automobile Workers of America an institution within the automobile industry. The so-called Automobile Dealer's Day in Court Act (Public Law 1026) in 1956 attempted to correct long-standing complaints about the retail selling of automobiles. The Motor Vehicle Air Pollution Act of 1965 and the National Traffic and Motor Vehicle Safety Act of 1966 regulated automotive design, and the 1970 Clean Air Act set stringent antiemission standards, leading to the universal use of catalytic converters. In 1975 the Energy Policy and Conservation Act required automakers' product lines to meet a steadily rising average fuel economy, beginning with 18 mpg in 1978 and rising to 27.5 (later reduced to 26) by 1985. Progressive governmental regulation of the post–World War II automobile industry, however, was accompanied by the massive, indirect subsidization of the Interstate Highway Act of 1956, which committed the federal government to pay, from a Highway Trust Fund, 90 percent of the construction costs for 41,000 miles (later 42,500 miles) of mostly toll-free express highways.

American reliance upon the automobile remained remarkably constant through peace and war, depression and prosperity. Although motor vehicle registrations declined slightly during the Great Depression, causing factory sales to dwindle to a low of 1.3 million units in 1932, the number of miles traveled by motor vehicle actually increased. Full recovery from the Depression was coupled with conversion of the automobile industry to meet the needs of the war effort. Production for the civilian market ceased early in 1942, with tires and gasoline severely rationed during the war. The industry converted to the manufacture of military items, contributing immeasurably to the Allied victory. After the war, pent-up demand and general affluence insured banner sales for Detroit, lasting into the late 1950s, when widespread dissatisfaction with the outcome of the automobile revolution began to become apparent.

Increasingly, in the 1960s, the automobile came to be recognized as a major social problem. Critics focused on its contributions to environmental pollution, urban sprawl, the rising cost of living, and accidental deaths and injuries. Much of the earlier romance of motoring was lost to a generation of Americans, who, reared in an automobile culture, accepted the motorcar as a mundane part of the establishment. While the automobile industry provided one out of every six jobs in the United States, its hegemony had been severely undercut over the preceding decades by proliferation of the size, power, and importance of government, which provided one out of every five jobs by 1970. With increased international involvement on the part of the United States, the rise of a nuclear warfare state, and the exploration of outer space, new industries more closely associated with the military-industrial complex—especially aerospace—became, along with the federal government, more important forces for change than the mature automobile industry.

These considerations notwithstanding, the American automobile culture continued to flourish in the 1960s. Drive-in facilities, automobile races, hot rodders, antique automobile buffs, and recreational vehicle enthusiasts all made their mark. And factory sales (over 11.2 million in 1972), registrations (more than 117 million), and the percentage of American families owning cars (83 percent) all indicated the country's reliance upon, if not necessarily its love for, automobiles. Whatever their problems, automobiles remained powerful cultural symbols of individualism, personal freedom, and mobility, even if certain realities—the industry's resistance to changing consumer demands, increasingly limited transportation alternatives, and lengthening average commutes—exposed some of the cracks in the symbol's veneer.

This phenomenal post–World War II proliferation of the U.S. automobile culture came to an abrupt halt in 1973–1974 with the onset of a worldwide energy crisis. Domestic oil reserves in mid-1973 were reported to be only 52 billion barrels, about a ten-year supply. Experts projected that crude petroleum imports would increase from 27 percent in 1972 to over 50 percent by 1980 and that all known world reserves of petroleum would be exhausted within fifty to seventy years. An embargo by the Arab oil-producing nations resulted, by 1 January 1974, in a ban on Sunday gasoline sales, a national 55-mph speed limit, five-to ten-gallon maximum limitations on gasoline purchases, and significantly higher prices at the pump. Despite short-range easing of the fuel shortage with the lifting of the Arab embargo, the crisis exposed potential limits on the further expansion of mass personal automobility.

The American auto industry was ill-prepared for the marked shift in consumer preference from large cars to smaller, more fuel-efficient alternatives, and, for the first quarter of 1974, Detroit's sales slipped drastically. Large cars piled up on storage lots and in dealers' showrooms, and massive layoffs accompanied the shifting of assembly lines to the production of smaller models. As the share of small cars in the U.S. market more than doubled from 27 percent in 1978 to 61.5 percent by 1981, the market share of imports began a slow and steady rise from 17.7 percent in 1978 to a high of 27.9 percent in 1982, with foreign imports taking over 25 percent of the U.S. market for passenger vehicles through 1990.

By the mid-1980s, however, the American automotive industry had begun a remarkable comeback, although its successes grew from its traditional strengths—big cars and cheap energy—rather than from adapting to the new paradigm that appeared inevitable in the late 1970s. Chrysler, on the verge of bankruptcy in 1979, led the turnaround. After securing a controversial $1.2 billion in federally guaranteed loans, the company promptly shed its overseas operations, modernized its management, and improved the quality of its product under the leadership of its new chief executive, Lee Iacocca. Chrysler's fuel-efficient K-car won awards, but in the long run its more successful innovation was the minivan, which found a highly profitable market niche and opened the door for the development of even larger and more-profitable "sport utility vehicles" (SUVs) in the 1990s. Ford, too, converted its more than $1 billion losses in 1980 and 1981 to profits of $1.87 billion in 1983 and $2.91 billion in 1984 by slashing payrolls, closing plants, and increasing operating efficiencies. With the rise of the SUV and the onset of recessions in Asia and the European Common Market, the percentage of foreign imports in the U.S. market dropped from 25.8 percent in 1990 to 14.9 percent in 1995, its lowest percentage since the late 1960s. And the average weight of American automobiles, which, through the use of lighter-weight materials and smaller designs, had dropped from 3,800 pounds in 1975 to 2,700 pounds in 1985, began a slow but steady march upward.

BIBLIOGRAPHY

Flink, James J. America Adopts the Automobile, 1895–1910. Cambridge, Mass.: MIT Press, 1970.

———. The Car Culture. Cambridge, Mass.: MIT Press, 1975.

Ingrassia, Paul J., and Joseph B. White. Comeback: The Fall and Rise of the American Automobile Industry. New York: Simon and Schuster, 1994.

McShane, Clay. Down the Asphalt Path: The Automobile and the American City. New York: Columbia University Press, 1994.

Rae, John Bell. The American Automobile: A Brief History. Chicago: University of Chicago Press, 1965.

———. The Road and the Car in American Life. Cambridge, Mass.: MIT Press, 1971.

Rothschild, Emma. Paradise Lost: The Decline of the Auto-Industrial Age. New York: Random House, 1973.

White, Lawrence J. The Automobile Industry Since 1945. Cambridge, Mass.: Harvard University Press, 1971.

James J.Flink

ChristopherWells

Dictionary of American History Flink, James J.; Wells, Christopher

Automobile

views updated May 23 2018

Automobile

Few inventions in modern times have had as much impact on human life and on the global environment as the automobile. Automobiles and trucks have had a strong influence on the history, economy, and social life of much of the world.

Entire societies, especially those of the industrialized countries, have been restructured around the power of rapid, long-distance movement that the automobile confers on individuals and around the flexible distribution patterns made possible by trucks. Automobiles have given great freedom of movement to their owners, but encourage sprawl (i.e., straggling, low-density urban development). Sprawl degrades landscapes and produces traffic congestion that tends to immobilize the automobiles that make sprawl itself possible. Furthermore, the dependence on petroleum fuel of automobiles and trucks, and thus of the economies based on these machines, imposes strong patterns on global politics, moving industrial societies such as the United States (which consumes approximately 25% of the world's oil production) to be deeply concerned with the power struggles of the Persian Gulf, where approximately 70% of the world's oil reserves are located.

The automobile is also a significant health hazard, both directly and indirectly. According to the United Nations, over a million people (both vehicle occupants and pedestrians) die every year on the world's roads; the United States alone loses over 40,000 lives annually to car crashes. Meanwhile, automobile exhausts are the largest single source of air pollution (in the United States). Air pollution from the manufacture and operation of automobiles contributes importantly to crop damage, acid rain , destruction of the ozone layer, lung disease , and early death by a variety of health problems. Sixteen percent of the world's annual greenhouse-gas production comes from automobiles; greenhouse gasses contribute to global climate change, which may disrupt food production and flood coasts and low islands worldwide.

The first automobiles, constructed in the late nineteenth century, were essentially horse-drawn carriages with the horses removed and engines installed. After more than a century of development, the modern automobile is a sophisticated system. It combines fuel efficiency and speed to offer the mobility and flexibility of use demanded by an enormous variety of lifestyles and industries. Automobiles affect every aspect of society, from the design of our cities, to police, ambulance, fire, and utility services, to such personal uses as vacation travel, dining, and shopping. Mass production techniques, first developed for the automobile in the early twentieth century, have been adapted for use in nearly every industry, providing for the efficient and inexpensive production of products.

Trucks, especially 18-wheel tractor-trailer trucks, have become the major form of transporting goods across the country, allowing, for example, produce to be quickly transported to markets while still fresh. The use of automotive technology—tractors, combines, pickers, sprayers, and other self-propelled machines—in agriculture has enabled farmers to increase the quantity, quality, and variety of our foods, albeit at the price of increased soil erosion rates, agricultural dependence on petroleum-derived fuels and fertilizers , and increased runoff pollution. Meanwhile, dozens of industries depend, directly or indirectly, on the automobile. These industries include producers of steel and other metals, plastics , rubber, glass , fabrics, petroleum products, and electronic components.

Structure of the automobile

Thousands of individual parts make up the modern automobile. Much like the human body, these parts are arranged into several semi-independent systems, each with a different function. For example, the human circulatory system comprises the heart , blood vessels, and blood. The automobile contains analogous circulatory systems for coolant fluid (mostly water ), for lubricating oil, and for fuel. The engine—the "heart" of the automobile—is comprised of pistons, cylinders, tubes to deliver fuel to the cylinders, and other components. Each system is necessary for making the automobile run and reducing noise and pollution.

The major systems of an automobile are the engine, fuel system, transmission, electrical system, cooling and lubrication system, and the chassis, which includes the suspension system, braking system, wheels and tires, and the body. These systems will be found in every form of motor vehicle and are designed to interact with and support each other.

Design factors

When an automobile is designed, the arrangement, choice, and type of components depend on various factors. The use of the automobile is one factor. Some cars are required only for local driving; these cars may be capable of achieving good fuel economy on short trips, but they may be less comfortable to drive at high speeds. A sports car, built for speed, will have enhanced steering and handling abilities, but requires a stronger engine, more fuel, and a more sophisticated suspension system. Yet, an automobile must also be flexible enough to perform in every situation and use.

Other factors in the design of automobiles include the requirements for pollution-control components that have been placed on the modern automobile. Safety features are also a factor in the automobile's design, affecting everything from the braking and steering systems to the materials used to construct the body. The design of the body must incorporate standards of safety, size and weight, aerodynamics or ways to reduce the friction of airflow, and appearance.

The choice of front-wheel drive allows for a smaller, more fuel-efficient car. But the arrangement of the engine and its relationship to other automobile systems will be different from a rear-wheel-driven car. Independent suspension for all four wheels improves the automobile's handling, safety, and comfort, but requires a more complex arrangement. The use of computer technology, the most recently added system to the automobile, requires changes in many of the car's other systems. Lastly, cost is an important factor in the design of a car. Many features useful for improving the various systems and characteristics of an automobile may make it too costly to produce and too expensive for many people to buy.

The design of an automobile, therefore, is a balance of many factors. Each must be taken into consideration, and compromises among features satisfy as many factors as possible. Yet, for all the variety among automobiles, the basic systems remain essentially the same.

Interaction of systems

Before examining the components of each system, it is useful to understand how the systems interact. The human body is again a good example of the interaction of systems. The heart pumps blood, which feeds the tissues of the body while at the same time helping to remove impurities. The tissues, fed by blood, are able to perform their tasks, and often are required to support the action of the heart. Muscle tissue , for example, depends on the availability of oxygen-rich blood from the heart in order to move the body.

The internal combustion engine is the heart of the automobile. The engine produces energy from fuel and converts that energy into the power to move the different components that will move the car. The engine converts the chemical energy produced by the burning of the fuel into mechanical energy. This energy is used to spin a shaft. The spinning shaft, through the interaction of the transmission and other components, causes the wheels to turn and the car to move. A similar transfer of energy to motion can be seen when bicycling. The up and down motion of the feet and legs is converted to the turning motion of the pedals, which in turn pulls the chain that causes the rear wheel to spin.

Just as it is more difficult to pedal a bicycle from a standstill than it is while already rolling, the engine requires the electrical system to give it the push to move on its own. The electric starter motor of an automobile provides a powerful force to give the engine its initial movement. The battery supplies energy for the engine to use when burning the fuel needed to make it run. The alternator is driven by a belt attached to the engine, recharging the battery so there will be a constant supply of energy. The sensors of the computer control system, which governs many of the processes in an automobile, also require electricity .

The burning of fuel is a hot, noisy process that also produces pollutants in the form of exhaust. This exhaust must be carried away from the engine and away from the automobile. The exhaust system, with its muffler, also acts to reduce the noise produced by the vehicle. Burning fuel in the cylinders produces two other results: friction and extremely high temperatures. In order to protect the parts from being worn down from the friction and from melting with the heat , they must be properly lubricated and cooled. These systems depend on the engine and the electrical system for the power to perform their tasks.

The engine's power is used to turn the automobile's wheels. Because the tires are the only parts of the automobile that are actually in contact with the road, they must rest on a system of supports that will carry the weight of the car and respond to conditions of the road surface. At the same time, the driver must be capable of guiding the direction of the automobile. Once an automobile is moving, it will continue to move until some sort of friction, the brake, is applied to stop it.

The wheels, suspension, steering, and braking systems are all attached to the car's chassis, as is the rest of the automobile. The chassis and body, analogous to the skeletal structure in the human body, provide support for all the various systems and components, while also providing safety, comfort, and protection from the elements for the automobile's passengers.

Engine

The engine operates on internal combustion ; that is, the fuel used for its power is burned inside the engine. This burning occurs inside cylinders. Within the cylinder is a piston. When the fuel is burned, it creates an explosive force that causes the piston to move up and down. The piston is attached, via a connecting rod, to a crankshaft, where the up and down movement of the piston converts to a circular motion. When bicycling, the upper part of a person's leg is akin to the piston. Power from the leg is passed through the pedal in order to turn the crank.

Gasoline is the most common automobile fuel. It is pulled into the cylinder by the vacuum created as the piston moves down through the cylinder. The gasoline is then compressed up into the cylinder by the next movement of the piston. A spark is introduced through a spark plug placed at the end of the cylinder. The spark causes the gasoline to explode, and the explosion drives the piston down again into the cylinder. This movement, called the power stroke, turns the crankshaft. A final movement of the piston upward again forces the exhaust gases, the byproducts of the fuel's combustion, from the cylinder. These four movements—intake, compression, power, and exhaust—are called strokes. The four-stroke engine is the most common type of automobile engine.

Most automobiles have from four to eight cylinders, although there are also two-cylinder and 12-cylinder automobiles. The cylinders work together in a sequence to turn the crankshaft, so that while one cylinder is in its intake stroke, another is in the compression stroke, and so forth. Generally, the more cylinders, the more smoothly the engine will run. The size of the automobile will affect the number of cylinders the engine uses. Smaller cars generally have the smaller four-cylinder engine. Mid-sized cars will generally require a six-cylinder engine, while larger cars need the power of an eight-cylinder engine.

The number of cylinders, however, is less important to the level of an engine's power than is its displacement. Displacement is a measure of the total volume of fuel mixture moved by all the pistons working together. The more fuel burned at one time, the more explosive the force, and thus, the power will be. Displacement is often expressed as cubic centimeters (cc) or as liters. A smaller engine will displace 1,200 cc (1.2 L) for 60 horsepower, while a larger engine may displace as much as 4,000 cc (4 L), generating more than 100 horsepower. Horsepower is the measurement of the engine's ability to perform work. The size and weight of the car also affects its power. It takes less work to propel a lighter car than a heavier car, even if they have the same engine, just as a horse carrying a single rider can go faster with less effort than a horse drawing a cart.

Fuel system

Gasoline must be properly mixed with air before it can be introduced into the cylinder. The combination of gasoline and air creates a more volatile explosion. The fuel pump draws the gasoline from the gas tank mounted toward the rear of the car. The gasoline is drawn into a carburetor on some cars, while it is fuel-injected on others; both devices mix the gasoline with air (approximately 14 parts of air to one part of gasoline) and spray this mixture as a fine mist into the cylinders. Other parts of the fuel system include the air cleaner, which is a filter to ensure that the air mixed into the fuel is free of impurities; and the intake manifold, which distributes the fuel mixture to the cylinders.

Exhaust system

After the fuel is burned in the pistons, the gases and heat created must be discharged from the cylinder to make room for the next infusion of fuel. The exhaust system is also responsible for reducing the noise caused by the explosion of the fuel.

Exhaust gases are discharged from the cylinder through an exhaust valve. The exhaust gathers in an exhaust manifold before eventually being channeled through the exhaust pipe and muffler and finally out the tailpipe and away from the car. The muffler is constructed with a maze of what are called baffles, specially developed walls that absorb energy, in the form of heat, force, and sound, as the exhaust passes through the muffler.

The burning of fuel creates additional byproducts of hazardous gases—hydrocarbons, carbon monoxide , and nitrogen oxide—which are harmful both to the engine's components and to the environment. The emission control system of a car is linked to the exhaust system, and functions in two primary ways. The first is to reduce the levels of unburned fuel. This is achieved by returning the exhaust to the fuel-air mixture injected into the cylinders to burn as much of the exhaust as possible. The second method is through a catalytic converter. Fitted before the muffler, the catalytic converter contains precious metals that act as catalysts. That is, they increase the rate of conversion of the harmful gases to less harmful forms.

Cooling system

The automobile uses an additional system to reduce the level of heat created by the engine. The cooling system also maintains the engine at a temperature that will allow it to run most efficiently. A liquid-cooled system is most commonly used.

The explosion of fuel in the cylinders can produce temperatures as high as 4,000°F (2,204°C); the temperature of exhaust gases, while cooler, still reach to 1,500°F (816°C). Liquid-cooling systems use water (mixed with an antifreeze that lowers the freezing point and raises the boiling point of water) guided through a series of jackets attached around the engine. As the water solution circulates through the jackets, it absorbs the heat from the engine. It is then pumped to the radiator at the front of the car, which is constructed of many small pipes and thin metal fins. These allow a large surface area to draw the heat from the water solution. A fan attached to the radiator uses the wind created by the movement of the car to cool the water solution further. Temperature sensors in the engine control the operation of the cooling system, so that the engine remains in its optimal temperature range.

Lubrication

Without proper lubrication, the heat and friction created by the rapid movements of the engine's parts would quickly cause it to fail. The lubrication system of an automobile acts to reduce engine wear caused by the friction of its metal parts, as well as to carry off heat. At the bottom of the engine is the crankcase, which holds a supply of oil. A pump, powered by the engine, carries oil from the crankcase and through a series of passages and holes to all the various parts of the engine. As the oil flows through the engine, it forms a thin layer between the moving parts, so that they do not actually touch. The heated oil drains back into the crankcase, where it cools. The fumes given off by the crankcase are circulated by the PCV (positive crankcase ventilation) valve back to the cylinders, where they are burned off, further reducing the level of pollution given off by the automobile.

Electrical system

Electricity is used for many parts of the car, from the headlights to the radio , but its chief function is to provide the electrical spark needed to ignite the fuel in the cylinders. This is performed by an electrical system comprises a battery, starter motor, alternator, distributor, ignition coil, and ignition switch. As discussed above, the starter motor is necessary for generating the power to carry the engine through its initial movements. Initial voltage is supplied by the battery, which is kept charged by the alternator. The alternator creates electrical current from the movement of the engine, much as windmills and watermills generate current from the movement of air or water.

Turning the key in the ignition switch draws current from the battery. This current, however, is not strong enough to provide spark to the spark plugs so it is drawn through the ignition coil, which is comprised of the tight primary winding and the looser secondary winding. The introduction of current between these windings creates a powerful magnetic field. Interrupting the current flow, which happens many times a second, causes the magnetic field to collapse. The collapsing of the magnetic field produces a powerful electrical surge. In this way, the 12-volt current from the battery is converted to the 20,000 volts needed as spark to ignite the gasoline.

Because there are two or more cylinders, and therefore as many spark plugs, this powerful current must be distributed—by the distributor—to each spark plug in a carefully controlled sequence. This sequence must be timed so that the cylinders and the pistons powering the crankshaft work smoothly together. For this reason, most automobiles manufactured today utilize an electronic ignition, in which a computer precisely controls the timing and distribution of current to the spark plugs.

Transmission

Once the pistons are firing and the crankshaft is spinning, this energy must be converted, or transmitted, to drive the wheels. But the crankshaft spins only within a limited range, usually between 1,000 to 6,000 revolutions per minute (rpm), and this is not enough power to cause the wheel to turn when applied directly. The transmission accomplishes the task of bringing the engine's torque (the amount of twisting force the crankshaft has as it spins) to a range that will turn the wheels. One way to experience the effect of torque is by using two wrenches, one with a short handle, the other with a long handle. It may be difficult to turn a nut with the shorter wrench; but the nut turns much more easily with the longer wrench, because it allows a more powerful twisting force. The transmission has two other functions: allowing reverse movement, and braking the engine.

There are two types of transmission: manual and automatic. With a manual transmission, the driver controls the shifting of the gears . In an automatic transmission, as its name implies, gears are engaged automatically. Both types of transmission make use of a clutch, which allows the gears to be engaged and disengaged.

Automobiles generally have at least three forward gears plus a reverse gear, although many manual transmissions have four or even five gears. Each gear provides a different ratio of the number of revolutions per minute (rpms) of the crankshaft (the power input) to the number of revolutions per minute of the output of the transmission, directed to the wheels. In first gear, for example, which is needed to move the automobile from a standstill, the ratio of input to output is 3.5 to one or even higher. The greater the ratio, the more torque will be achieved in the output. Each successively higher gear has a lower input to output ratio. This is because once the automobile is rolling, progressively less torque is needed to maintain its movement. The fourth and fifth gears found on most cars are used when the engine has achieved higher speeds; often called overdrive gears, these gears allow the input to output ratio to sink lower than one to one. In other words, the wheels are spinning faster than the crankshaft. This allows for higher speeds and greater fuel efficiency.

Chassis

The chassis is the framework to which the various parts of the automobile are mounted. The chassis must be strong enough to bear the weight of the car, yet somewhat flexible in order to sustain the shocks and tension caused by turning and road conditions. Attached to the chassis are the wheels and steering assembly, the suspension, the brakes, and the body.

The suspension system enables the automobile to absorb the shocks and variations in the road surface, keeping the automobile stable. Most cars feature independent front suspension, that is, the two wheels in front are supported independently of each other. In this way, if one wheel hits a bump while the other wheel is in a dip, both wheels will maintain contact with the road. This is especially important because steering the automobile is performed with the front wheels. More and more cars also feature independent rear suspension, improving handling and the smoothness of the ride.

The main components of the suspension system are the springs and the shock absorbers. The springs suspend the automobile above the wheel, absorbing the shocks and bumps in the road surface. As the chassis bounces on the springs, the shock absorbers act to dampen, or quiet, the movement of the springs, using tubes and chambers filled with hydraulic fluid.

The steering system is another part of the suspension system. It allows the front wheels to guide the automobile. The steering wheel is attached to the steering column, which in turn is fitted to a gear assembly that allows the circular movement of the steering wheel to be converted to the more linear, or straight, movement of the front wheels. The gear assembly is attached to the front axle by tie rods. The axle is connected to the hubs of the wheels.

Wheels and the tires around them are the only contact the automobile has with the road. Tires are generally made of layers of rubber or synthetic rubber around steel fibers that greatly increase the rubber's strength and ability to resist puncture. Tires are inflated with air at a level that balances the greatest contact with the road surface with the ability to offer puncture resistance. Proper inflation of the tires will decrease wear on the tires and improve fuel efficiency.

Body

The body of a car is usually composed of steel or aluminum , although fiberglass and plastic are also used. The body is actually a part of the chassis, the whole formed by welding stamped components into a single unit. While the body forms the passenger compartment, offers storage space , and houses the automobile's systems, it has other important functions as well. Passenger safety is achieved by providing structural support strong enough to withstand the force of an accident. Other parts of the car, such as the front and hood, are designed to crumple in a crash, thereby absorbing much of the impact. A firewall between the engine and the interior of the car protects the passengers in case of an engine fire. Lastly, the body's shape contributes to reducing the level of wind resistance as the car moves, allowing the driver better handling and improving fuel efficiency.

Hybrids

In the last few years several makes of affordable hybrid cars have appeared on the U.S. market. Hybrid cars burn gasoline in an efficient engine to produce electricity. This power is then stored in batteries and used to run an electric motor , and power from the electric motor is combined with power from the gasoline motor to move the car. Today's commercially-available hybrid cars produce a small fraction of the air pollution per mile traveled that is produced by conventional cars of comparable size, and get significantly better mileage as well.

Resources

books

Duffy, James E. Modern Automotive Mechanics. Tinley Park, IL: Goodheart-Willcox Publisher, 1990.

Lewis, David L., and Laurence Goldstein, eds. The Automobile and American Culture. Ann Arbor: University of Michigan Press, 1986.

Magliozzi, Tom and Ray. Car Talk. New York: Dell Publishing, 1991.

Thiessen, Frank J., and David N. Dales. Automotive Principles andService. 4th ed. Upper Saddle River, NJ: Prentice Hall, 1993.

other

Fowler, Jonathan. "Traffic Deaths on Rise Globally." Associated Press. August 29, 2002 [cited October 19, 2002]. <http://www.twincities.com/mld/twincities/3962244.htm>.

Hermance, David, and Shoichi Sasaki. "Hybrid Vehicles Take to the Streets." IEEE Spectrum. November, 1998 [cited October 19, 2002]. <http://www.spectrum.ieee.org/select/1198/hyb.html>.

International Center for Technology Assessment. "The Real Price of Gasoline" 2002 [cited October 17, 2002]. <http://www.icta.org/projects/trans/realpricegas.pdf>.

U.S. Census Bureau. "2001 Statistical Abstract of the United States" [cited Oct. 19, 2002]. <http://www.census.gov/prod/2002pubs/01statab/trans.pdf>.

M.L. Cohen

KEY TERMS

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Catalyst: —Any agent that accelerates a chemical reaction without entering the reaction or being changed by it.
Combustion: —A form of oxidation that occurs so rapidly that noticeable heat and light are produced.
Friction: —A force caused by the movement of an object through liquid, gas, or against a second object that works to oppose the first object's movement.
Gear: —A wheel arrayed with teeth that meshes with the teeth of a second wheel to move it.
Ratio: —A measurement in quantity, size, or speed of the relationship between two or more things.
Shaft: —A rod that, when spun, can be used to move other parts of a machine.
Torque: —The ability or force needed to turn or twist a shaft or other object.
Voltage: —Measured in volts, the amount of electrons moved by an electric current or charge.

The Gale Encyclopedia of Science

Automobile

views updated May 14 2018

Automobile

Background

In 1908 Henry Ford began production of the Model T automobile. Based on his original Model A design first manufactured in 1903, the Model T took five years to develop. Its creation inaugurated what we know today as the mass production assembly line. This revolutionary idea was based on the concept of simply assembling interchangeable component parts. Prior to this time, coaches and buggies had been hand-built in small numbers by specialized craftspeople who rarely duplicated any particular unit. Ford's innovative design reduced the number of parts needed as well as the number of skilled fitters who had always formed the bulk of the assembly operation, giving Ford a tremendous advantage over his competition.

Ford's first venture into automobile assembly with the Model A involved setting up assembly stands on which the whole vehicle was built, usually by a single assembler who fit an entire section of the car together in one place. This person performed the same activity over and over at his stationary assembly stand. To provide for more efficiency, Ford had parts delivered as needed to each work station. In this way each assembly fitter took about 8.5 hours to complete his assembly task. By the time the Model T was being developed Ford had decided to use multiple assembly stands with assemblers moving from stand to stand, each performing a specific function. This process reduced the assembly time for each fitter from 8.5 hours to a mere 2.5 minutes by rendering each worker completely familiar with a specific task.

Ford soon recognized that walking from stand to stand wasted time and created jam-ups in the production process as faster workers overtook slower ones. In Detroit in 1913, he solved this problem by introducing the first moving assembly line, a conveyor that moved the vehicle past a stationary assembler. By eliminating the need for workers to move between stations, Ford cut the assembly task for each worker from 2.5 minutes to just under 2 minutes; the moving assembly conveyor could now pace the stationary worker. The first conveyor line consisted of metal strips to which the vehicle's wheels were attached. The metal strips were attached to a belt that rolled the length of the factory and then, beneath the floor, returned to the beginning area. This reduction in the amount of human effort required to assemble an automobile caught the attention of automobile assemblers throughout the world. Ford's mass production drove the automobile industry for nearly five decades and was eventually adopted by almost every other industrial manufacturer. Although technological advancements have enabled many improvements to modern day automobile assembly operations, the basic concept of stationary workers installing parts on a vehicle as it passes their work stations has not changed drastically over the years.

Raw Materials

Although the bulk of an automobile is virgin steel, petroleum-based products (plastics and vinyls) have come to represent an increasingly large percentage of automotive components. The light-weight materials derived from petroleum have helped to lighten some models by as much as thirty percent. As the price of fossil fuels continues to rise, the preference for lighter, more fuel efficient vehicles will become more pronounced.

Design

Introducing a new model of automobile generally takes three to five years from inception to assembly. Ideas for new models are developed to respond to unmet pubic needs and preferences. Trying to predict what the public will want to drive in five years is no small feat, yet automobile companies have successfully designed automobiles that fit public tastes. With the help of computer-aided design equipment, designers develop basic concept drawings that help them visualize the proposed vehicle's appearance. Based on this simulation, they then construct clay models that can be studied by styling experts familiar with what the public is likely to accept. Aerodynamic engineers also review the models, studying air-flow parameters and doing feasibility studies on crash tests. Only after all models have been reviewed and accepted are tool designers permitted to begin building the tools that will manufacture the component parts of the new model.

The Manufacturing
Process

Components

1 The automobile assembly plant represents only the final phase in the process of manufacturing an automobile, for it is here that the components supplied by more than 4,000 outside suppliers, including company-owned parts suppliers, are brought together for assembly, usually by truck or railroad. Those parts that will be used in the chassis are delivered to one area, while those that will comprise the body are unloaded at another.

Chassis

2 The typical car or truck is constructed from the ground up (and out). The frame forms the base on which the body rests and from which all subsequent assembly components follow. The frame is placed on the assembly line and clamped to the conveyer to prevent shifting as it moves down the line. From here the automobile frame moves to component assembly areas where complete front and rear suspensions, gas tanks, rear axles and drive shafts, gear boxes, steering box components, wheel drums, and braking systems are sequentially installed.
The automobile, for decades the quintessential American industrial product, did not have its origins in the United States. In 1860, Etienne Lenoir, a Belgian mechanic, introduced an internal combustion engine that proved useful as a source of stationary power. In 1878, Nicholas Otto, a German manufacturer, developed his four-stroke "explosion" engine. By 1885, one of his engineers, Gottlieb Daimler, was building the first of four experimental vehicles powered by a modified Otto internal combustion engine. Also in 1885, another German manufacturer, Carl Benz, introduced a three-wheeled, self-propelled vehicle. In 1887, the Benz became the first automobile offered for sale to the public. By 1895, automotive technology was dominated by the French, led by Emile Lavassor. Lavassor developed the basic mechanical arrangement of the car, placing the engine in the front of the chassis, with the crankshaft perpendicular to the axles.
In 1896, the Duryea Motor Wagon became the first production motor vehicle in the United States. In that same year, Henry Ford demonstrated his first experimental vehicle, the Quadricycle. By 1908, when the Ford Motor Company introduced the Model T, the United States had dozens of automobile manufacturers. The Model T quickly became the standard by which other cars were measured; ten years later, half of all cars on the road were Model Ts. It had a simple four-cylinder, twenty-horsepower engine and a planetary transmission giving two gears forward and one backward. It was sturdy, had high road clearance to negotiate the rutted roads of the day, and was easy to operate and maintain.
William S. Pretzer
3 An off-line operation at this stage of production mates the vehicle's engine with its transmission. Workers use robotic arms to install these heavy components inside the engine compartment of the frame. After the engine and transmission are installed, a worker attaches the radiator, and another bolts it into place. Because of the nature of these heavy component parts, articulating robots perform all of the lift and carry operations while assemblers using pneumatic wrenches bolt component pieces in place. Careful ergonomic studies of every assembly task have provided assembly workers with the safest and most efficient tools available.

Body

4 Generally, the floor pan is the largest body component to which a multitude of panels and braces will subsequently be either welded or bolted. As it moves down the assembly line, held in place by clamping fixtures, the shell of the vehicle is built. First, the left and right quarter panels are robotically disengaged from pre-staged shipping containers and placed onto the floor pan, where they are stabilized with positioning fixtures and welded.
5 The front and rear door pillars, roof, and body side panels are assembled in the same fashion. The shell of the automobile assembled in this section of the process lends itself to the use of robots because articulating arms can easily introduce various component braces and panels to the floor pan and perform a high number of weld operations in a time frame and with a degree of accuracy no human workers could ever approach. Robots can pick and load 200-pound (90.8 kilograms) roof panels and place them precisely in the proper weld position with tolerance variations held to within .001 of an inch. Moreover, robots can also tolerate the smoke, weld flashes, and gases created during this phase of production.
6 As the body moves from the isolated weld area of the assembly line, subsequent body components including fully assembled doors, deck lids, hood panel, fenders, trunk lid, and bumper reinforcements are installed. Although robots help workers place these components onto the body shell, the workers provide the proper fit for most of the bolt-on functional parts using pneumatically assisted tools.

Paint

7 Prior to painting, the body must pass through a rigorous inspection process, the body in white operation. The shell of the vehicle passes through a brightly lit white room where it is fully wiped down by visual inspectors using cloths soaked in hi-light oil. Under the lights, this oil allows inspectors to see any defects in the sheet metal body panels. Dings, dents, and any other defects are repaired right on the line by skilled body repairmen. After the shell has been fully inspected and repaired, the assembly conveyor carries it through a cleaning station where it is immersed and cleaned of all residual oil, dirt, and contaminants.
8 As the shell exits the cleaning station it goes through a drying booth and then through an undercoat dip—an electrostatically charged bath of undercoat paint (called the E-coat) that covers every nook and cranny of the body shell, both inside and out, with primer. This coat acts as a substrate surface to which the top coat of colored paint adheres.
9 After the E-coat bath, the shell is again dried in a booth as it proceeds on to the final paint operation. In most automobile assembly plants today, vehicle bodies are spray-painted by robots that have been programmed to apply the exact amounts of paint to just the right areas for just the right length of time. Considerable research and programming has gone into the dynamics of robotic painting in order to ensure the fine "wet" finishes we have come to expect. Our robotic painters have come a long way since Ford's first Model Ts, which were painted by hand with a brush.
10 Once the shell has been fully covered 1 V with a base coat of color paint and a clear top coat, the conveyor transfers the bodies through baking ovens where the paint is cured at temperatures exceeding 275 degrees Fahrenheit (135 degrees Celsius). After the shell leaves the paint area it is ready for interior assembly.

Interior assembly

11 The painted shell proceeds through the interior assembly area where workers assemble all of the instrumentation and wiring systems, dash panels, interior lights, seats, door and trim panels, headliners, radios, speakers, all glass except the automobile windshield, steering column and wheel, body weatherstrips, vinyl tops, brake and gas pedals, carpeting, and front and rear bumper fascias.
12 Next, robots equipped with suction cups remove the windshield from a shipping container, apply a bead of urethane sealer to the perimeter of the glass, and then place it into the body windshield frame. Robots also pick seats and trim panels and transport them to the vehicle for the ease and efficiency of the assembly operator. After passing through this section the shell is given a water test to ensure the proper fit of door panels, glass, and weatherstripping. It is now ready to mate with the chassis.

Mate

13 The chassis assembly conveyor and the body shell conveyor meet at this stage of production. As the chassis passes the body conveyor the shell is robotically lifted from its conveyor fixtures and placed onto the car frame. Assembly workers, some at ground level and some in work pits beneath the conveyor, bolt the car body to the frame. Once the mating takes place the automobile proceeds down the line to receive final trim components, battery, tires, anti-freeze, and gasoline.
14 The vehicle can now be started. From here it is driven to a checkpoint off the line, where its engine is audited, its lights and horn checked, its tires balanced, and its charging system examined. Any defects discovered at this stage require that the car be taken to a central repair area, usually located near the end of the line. A crew of skilled trouble-shooters at this stage analyze and repair all problems. When the vehicle passes final audit it is given a price label and driven to a staging lot where it will await shipment to its destination.

Quality Control

All of the components that go into the automobile are produced at other sites. This means the thousands of component pieces that comprise the car must be manufactured, tested, packaged, and shipped to the assembly plants, often on the same day they will be used. This requires no small amount of planning. To accomplish it, most automobile manufacturers require outside parts vendors to subject their component parts to rigorous testing and inspection audits similar to those used by the assembly plants. In this way the assembly plants can anticipate that the products arriving at their receiving docks are Statistical Process Control (SPC) approved and free from defects.

Once the component parts of the automobile begin to be assembled at the automotive factory, production control specialists can follow the progress of each embryonic automobile by means of its Vehicle Identification Number (VIN), assigned at the start of the production line. In many of the more advanced assembly plants a small radio frequency transponder is attached to the chassis and floor pan. This sending unit carries the VIN information and monitors its progress along the assembly process. Knowing what operations the vehicle has been through, where it is going, and when it should arrive at the next assembly station gives production management personnel the ability to electronically control the manufacturing sequence. Throughout the assembly process quality audit stations keep track of vital information concerning the integrity of various functional components of the vehicle.

This idea comes from a change in quality control ideology over the years. Formerly, quality control was seen as a final inspection process that sought to discover defects only after the vehicle was built. In contrast, today quality is seen as a process built right into the design of the vehicle as well as the assembly process. In this way assembly operators can stop the conveyor if workers find a defect. Corrections can then be made, or supplies checked to determine whether an entire batch of components is bad. Vehicle recalls are costly and manufacturers do everything possible to ensure the integrity of their product before it is shipped to the customer. After the vehicle is assembled a validation process is conducted at the end of the assembly line to verify quality audits from the various inspection points throughout the assembly process. This final audit tests for properly fitting panels; dynamics; squeaks and rattles; functioning electrical components; and engine, chassis, and wheel alignment. In many assembly plants vehicles are periodically pulled from the audit line and given full functional tests. All efforts today are put forth to ensure that quality and reliability are built into the assembled product.

The Future

The development of the electric automobile will owe more to innovative solar and aeronautical engineering and advanced satellite and radar technology than to traditional automotive design and construction. The electric car has no engine, exhaust system, transmission, muffler, radiator, or spark plugs. It will require neither tune-ups nor—truly revolutionary—gasoline. Instead, its power will come from alternating current (AC) electric motors with a brushless design capable of spinning up to 20,000 revolutions/minute. Batteries to power these motors will come from high performance cells capable of generating more than 100 kilowatts of power. And, unlike the lead-acid batteries of the past and present, future batteries will be environmentally safe and recyclable. Integral to the braking system of the vehicle will be a power inverter that converts direct current electricity back into the battery pack system once the accelerator is let off, thus acting as a generator to the battery system even as the car is driven long into the future.

The growth of automobile use and the increasing resistance to road building have made our highway systems both congested and obsolete. But new electronic vehicle technologies that permit cars to navigate around the congestion and even drive themselves may soon become possible. Turning over the operation of our automobiles to computers would mean they would gather information from the roadway about congestion and find the fastest route to their instructed destination, thus making better use of limited highway space. The advent of the electric car will come because of a rare convergence of circumstance and ability. Growing intolerance for pollution combined with extraordinary technological advancements will change the global transportation paradigm that will carry us into the twenty-first century.

Where To Learn More

Books

Abernathy, William. The Productivity Dilemma: Roadblock to Innovation in the Automobile Industry. Johns Hopkins University Press, 1978.

Gear Design, Manufacturing & Inspection Manual. Society of Manufacturing Engineers, Inc., 1990.

Hounshell, David. From the American System to Mass Production. Johns Hopkins University Press, 1984.

Lamming, Richard. Beyond Partnership: Strategies for Innovation & Lean Supply. Prentice Hall, 1993.

Making the Car. Motor Vehicle Manufacturers Association of the United States, 1987.

Mortimer, J., ed. Advanced Manufacturing in the Automotive Industry. Springer-Verlag New York, Inc., 1987.

Mortimer, John. Advanced Manufacturing in the Automotive Industry. Air Science Co., 1986.

Nevins, Allen and Frank E. Hill. Ford: The Times, The Man, The Company. Scribners, 1954.

Seiffert, Ulrich. Automobile Technology of the Future. Society of Automotive Engineers, Inc., 1991.

Sloan, Alfred P. My Years with General Motors. Doubleday, 1963.

Periodicals

"The Secrets of the Production Line," The Economist. October 17, 1992, p. S5.

—Rick Bockmiller

How Products Are Made Bockmiller, Rick

Automobile

views updated May 17 2018

Automobile

No invention in modern times has had as much of an impact on human life as the invention of the automobile. It has become an important influence on the history, economy, and social life of much of the world. In fact, the rapid growth of the United States in the twentieth century can be directly related to the automobile.

Automobiles reach into every aspect of society, from the design of our cities to such personal uses as vacation travel, dining, and shopping. Mass-production techniques, first developed for the automobile, have been adapted for use in nearly every industry. Meanwhile, dozens of industries depend, directly or indirectly, on the automobile. These industries include producers of steel and other metals, plastics, rubber, glass, fabrics, petroleum products, and electronic components.

Structure of the automobile

Hundreds of individual parts make up the essential components of the modern automobile. Much like the human body, these parts are arranged into several systems, each with a different function. Each system is necessary for making the automobile run, keeping it safe, and reducing noise and pollution.

The major systems of an automobile are the engine, fuel system, exhaust system, cooling system, lubrication system, electrical system, transmission, and the chassis. The chassis includes the wheels and tires, the brakes, the suspension system, and the body. These systems will be found in every form of motor vehicle and are designed to interact with and support each other.

Engine. The engine—the "heart" of the automobile—operates on internal combustion, meaning the fuel used for its power is burned inside

of the engine. This burning occurs inside cylinders, which contain pistons. The pistons are attached, via a connecting rod, to a crankshaft. Gasoline, the most common automobile fuel, is pulled into the cylinder by the vacuum created as the piston moves down through the cylinder. The gasoline is then compressed up into the cylinder by the upward movement of the piston. A spark is introduced through a spark plug placed at the end of the cylinder. The spark causes the gasoline to explode, and the explosion drives the piston down again into the cylinder. This movement, called the power stroke, turns the crankshaft. A final movement of the piston upward again forces the exhaust gases, the byproducts of the fuel's combustion, from the cylinder. These four movements—intake, compression, power, exhaust—are called strokes. The four-stroke engine is the most common type of automobile engine.

Fuel system. Gasoline must be properly mixed with air before it can be introduced into the cylinder. The combination of gasoline and air creates a greater explosion. The fuel pump draws the gasoline from the gas tank mounted at the rear of the car. The gasoline is drawn into a carburetor on some cars, while it is fuel-injected on others. Both devices mix the gasoline with air (approximately 14 parts of air to 1 part of gasoline) and spray this mixture as a fine mist into the cylinders. Other parts of the fuel system include the air cleaner (a filter to ensure that the air mixed into the fuel is free of impurities) and the intake manifold (distributes the fuel mixture to the cylinders).

Exhaust system. After the fuel is burned in the pistons, the gases and heat created must be released from the cylinder to make room for the next intake of fuel. The exhaust system is also responsible for reducing the noise caused by the explosion of the fuel.

Exhaust gases are released from the cylinder through an exhaust valve. The gases gather in an exhaust manifold before eventually being channeled through the exhaust pipe and muffler and finally out the tailpipe and away from the car. The muffler is constructed with a maze of baffles, specially developed walls that absorb energy (in the form of heat, force, and sound) as the exhaust passes through the muffler.

The burning of fuel creates hazardous gases (hydrocarbons, carbon monoxide, and nitrogen oxide) that are extremely harmful to the engine's components and the environment. The emission control system of a car, linked to the exhaust system, functions in two primary ways. First, it reduces the levels of unburned fuel by burning as much of the exhaust as possible. It does this by returning the exhaust to the fuel-air mixture injected into the cylinders. Second, it uses a catalytic converter (fitted before the muffler) to increase the conversion of the harmful gases to less harmful forms.

Cooling system. The cooling system also maintains the engine at a temperature that will allow it to run most efficiently. A liquid-cooled system is most commonly used. The explosion of fuel in the cylinders can produce temperatures as high as 4000°F (2204°C). Liquid-cooling systems use water (mixed with an antifreeze that lowers the freezing point and raises the boiling point of water) guided through a series of jackets attached around the engine. As the water solution circulates through the jackets, it absorbs the heat from the engine. It is then pumped to the radiator at the front of the car, which is constructed of many small pipes and thin metal fins. This design creates a large surface area that draws the heat from the water solution. A fan attached to the radiator uses the wind created by the movement of the car to cool the water solution further. Temperature sensors in the engine control the operation of the cooling system so that the engine remains in its optimal temperature range.

Lubrication. Without the proper lubrication, the heat and friction created by the rapid movements of the engine's parts would quickly cause it to fail. At the bottom of the engine is the crankcase, which holds a supply of oil. A pump, powered by the engine, carries oil from the crankcase and through a series of passages and holes to all the various parts of the engine. As the oil flows through the engine, it forms a thin layer between the moving parts so they do not actually touch. The heated oil drains back into the crankcase, where it cools. The fumes given off by the crankcase are circulated by the PCV (positive crankcase ventilation) valve back to the cylinders, where they are burned off, further reducing the level of pollution given off by the automobile.

Electrical system. Electricity is used for many parts of the car, from the headlights to the radio, but its chief function is to provide the electrical spark needed to ignite the fuel in the cylinders. The electrical system is comprised of a battery, starter motor, alternator, distributor, ignition coil, and ignition switch. The starter motor is necessary for generating the power to carry the engine through its initial movements. Initial voltage is supplied by the battery, which is kept charged by the alternator. The alternator creates electrical current from the movement of the engine, much as windmills and watermills generate current from the movement of air or water.

Turning the key in the ignition switch draws electrical current from the battery. This current, however, is not strong enough to provide spark to the spark plugs. The current is therefore drawn through the ignition coil, which is comprised of the tight primary winding and the looser secondary winding. The introduction of current between these windings creates a powerful magnetic field. Interrupting the current flow, which happens many times a second, causes the magnetic field to collapse. The collapsing of the magnetic field produces a powerful electrical surge. In this way, the 12-volt current from the battery is converted to the 20,000 volts needed to ignite the gasoline.

Because there are two or more cylinders, and therefore as many spark plugs, this powerful current must be distributed—by the distributor—to each spark plug in a carefully controlled sequence. This sequence must be carefully timed so that the cylinders, and the pistons powering the crankshaft, work smoothly together. For this reason, most present-day automobiles utilize an electronic ignition, in which a computer precisely controls the timing and distribution of current to the spark plugs.

Transmission. Once the pistons are firing and the crankshaft is spinning, this energy must be converted, or transmitted, to drive the wheels. The crankshaft spins only within a limited range, usually between 1,000 to 6,000 revolutions per minute (rpm). Although the wheels spin at far lower rpms, the range at which they spin is wider (to accommodate the wide range of driving speeds of an automobile). The gears of the transmission accomplish the task of bringing down the fast-spinning input from the crankshaft to the smaller number of rpms needed by the wheels.

There are two types of transmission: manual and automatic. Automobiles generally have at least three gears, plus a reverse gear (many manual transmissions have four or even five gears). With manual transmission, the driver controls the shifting of the gears. In an automatic transmission, gears are engaged automatically. Both types of transmission make use of a clutch, which allows the gears to be engaged and disengaged.

Chassis. The chassis is the framework to which the various parts of the automobile are mounted. The chassis must be strong enough to bear the weight of the car, yet somewhat flexible in order to sustain the shocks and tension caused by turning and road conditions. Attached to the chassis are the wheels and steering assembly, the brakes, the suspension, and the body.

The steering system allows the front wheels to guide the automobile. The steering wheel is attached to the steering column, which in turn is fitted to a gear assembly that allows the circular movement of the steering wheel to be converted to the straight movement of the front wheels. The gear assembly is attached to the front axle by tie rods. The axle is connected to the hubs of the wheels.

Wheels and the tires around them form the automobile's only contact with the road. Tires are generally made of layers of rubber or synthetic rubber around steel fibers that greatly increase the rubber's strength and ability to resist puncture. Proper inflation of the tires improves fuel efficiency and decreases wear on the tires. When applied to the wheels, brakes provide friction that causes the wheels to stop turning.

The suspension system enables the automobile to absorb the bumps and variations in the road surface, keeping the automobile stable. Most cars feature independent front suspension (the two wheels in front are supported separately). In this way, if one wheel hits a bump while the other wheel is in a dip, both wheels will maintain contact with the road. This is especially important because steering the automobile is performed with the front wheels. More and more cars also feature independent rear suspension, improving handling and the smoothness of the ride.

The main components of the suspension system are the springs and the shock absorbers. The springs suspend the automobile above the wheel, absorbing the bumps in the road surface. As the chassis bounces on the springs, the shock absorbers act to dampen, or quiet, the movement of the springs.

The body of a car is usually composed of steel or aluminum, although fiberglass and plastic are also used. While the body forms the passenger compartment, offers storage space, and houses the automobile's systems, it has other important functions as well. In most instances, its solid structure protects passengers from the force of an accident. Other parts of the car, such as the front and hood, are designed to crumple easily, thereby absorbing much of the impact of a crash. A firewall between the engine and the interior of the car protects passengers in case of a fire. Lastly, the body's design helps to reduce the level of wind resistance as the car moves, allowing the driver better handling ability and improving the efficiency of the engine.

[See also Internal combustion engine ]

UXL Encyclopedia of Science

Automobile

views updated May 17 2018

AUTOMOBILE

gendering the automobile
social distinctions
limits of nineteenth-century automobilism
bibliography

Germans Carl Friedrich Benz (1844–1929) and Gottlieb Wilhelm Daimler (1834–1900), working separately in the 1880s, both invented small and sufficiently efficient internal combustion engines for a variety of uses. Showing potential applications, each mounted his engine on a chassis. Soon French metalworking firms, most notably Panhard et Levassor and Peugeot, but including a host of other companies, began using the new technology to produce small, gasoline-powered cars. When Édouard Michelin (1856–1940) placed the new contraption on pneumatic tires, the automobile became more efficient, more comfortable, and more marketable. The internal combustion engine riding on pneumatic tires became the dominant way to power an automobile.

Until the first decade of the twentieth century, automobiles were the domain of inventors and very wealthy sportsmen. Although the French were widely reputed to have the best roads in Europe—a fact attributed to the elite Corps des Ponts et Chaussées, Napoleonic road building, and better maintenance—even there conditions were hazardous. Across Europe, driving was an adventure, requiring neither drivers' licenses nor car inspections. Early road races, in which circuits were established on preexisting country roads, were feats of survival given uneven surfaces, curves, hills, lack of safety features on cars, mechanical breakdowns, and frequent tire blowouts.

At the turn of the century, wealthy Europeans began to buy automobiles for touring and not just sport, pressuring governments for better roads and creating a veritable tourist infrastructure. Automobile and touring clubs began to publish road maps and directories of mechanics, hotels at which to stay, and businesses selling tires and gasoline. Tire companies followed suit, as they wanted to encourage tourists to travel more, using more tires: Michelin set the pace with the first Red Guide to France in 1900, then Continental and Dunlop copied the effort. Touring clubs and manufacturers both placed road signs designed for automobiles and lobbied governments to take on the responsibility and substantial cost.

gendering the automobile

In the late nineteenth century, automobiles were often compared with women, suggesting that both automobiles and women were male possessions. In advertisements, half-naked women were draped over automobiles, implying that the male buyer of the auto mobile either got the woman as part of the package, or that he would become so irresistible in his new car that any woman would happily undress for him.

The Michelin tire company similarly made the comparison between women and automobiles. But unlike most advertisers, which used mere images and little text, Michelin published weekly newspaper articles, designed to be humorous. In 1914, in the mass-circulation Le Journal, the "Michelin Man" declared the ways that an automobile resembled a woman:

Woman, says the Arab proverb, shares our pains, doubles our joys, and triples our expenses. One can say the same thing about the automobile…. The automobile, like woman, makes us see the country…. To steer her one needs softness, a certain touch, and one recognizes this experience among those who have gotten around. You will tell me that the automobile has the superiority of silence. Would you be quiet! A pretty woman and a car, what could be better for expanding one's circle of acquaintances? The owner of a pretty car and the husband of a pretty woman never risk having too few friends… and which costs the most, whether you are talking about a woman or a car? Maintenance… I can't pursue this comparison. It could go on into infinity. ("Le Lundi de Michelin," Le Journal, 6 April 1914, p. 5)

Automobiles were clearly gendered, and they were gendered in a way that tended to reinforce existing stereotypes, not to mention male dominance.

With engines invented in Germany, cycling technology perfected in Britain, and a series of French innovations, the automobile was at root European. Within Europe and the world, France quickly became the center of the prewar automobile industry. Until 1904–1905, when cheap Oldsmobiles and Fords emerged in the United States, France produced more automobiles than any country in the world. In 1914, France still exported more automobiles than any other country, including the United States. Within Europe, there were more cars produced in France, and more driven in France, than in any other country. Within France and in Europe generally, the automobile was an article de luxe, a luxury item much like the fine silks

and wines that French manufacturers sold to the European bourgeoisie.

social distinctions

Without much practical use in Europeans' daily lives before 1914, automobiles offered the kind of social distinction money could buy. Neither the working class nor the lower middle class could afford automobiles, let alone the very steep maintenance costs: in 1901, a single tire, unlikely to last more than a couple of thousand kilometers, cost the equivalent of thirty-three days of work by an adult male laborer in the French provinces. The well-heeled upper middle class constituted the primary market before World War I, and advertisements implied that they could be aristocratic if they bought automobiles and their accessories. Advertisements reminded potential buyers that King Edward VII (r. 1901–1910) of the United Kingdom was an auto enthusiast. Automobile and tire makers named which heads of state and which famed aristocrats drove their products or rode on their tires. The message was clear: by buying a certain kind of automobile, a bourgeois man could have the next best thing to royal or aristocratic lineage.

Early distribution reinforced the image of automobiles as a luxury good. In the annual automobile salons, manufacturers set up exhibits, showing off their products. Potential buyers walked through the salon and ordered a chassis, a motor, any accessories, and then waited for their automobile to be built. The assembly line was not introduced until the eve of World War I and was not widespread in Europe until the interwar years; automobiles before 1914 were essentially custom-made, much as a bourgeois man would go to a tailor, choose a fabric, be measured, and have his suit made. Advertising posters also focused on automobiles as a luxury, a means of setting oneself off from others.

limits of nineteenth-century automobilism

The environmental challenges posed by the automobile were not obvious in 1914, as most people still traveled by foot, horse, and train, when they traveled at all. And despite the dreams of automobile manufacturers, it was not obvious that the automobile would eventually become a practical conveyance for many, let alone most, Europeans. It was, after all, World War I that first illustrated just how practical automobiles might be: in September 1914, prewar Renault taxis from Paris helped to halt the German advance at the battle of the Marne; in 1917, truck traffic on the voie sacrée to Verdun moved men and supplies to the fortress. Only in the interwar years did the lower middle class begin to buy automobiles, and the mass market for automobiles in Europe developed only after World War II.

bibliography

Bardou, Jean-Pierre, et al. The Automobile Revolution: The Impact of an Industry. Translated by James M. Laux. Chapel Hill, N.C., 1982.

Bertho Lavenir, Catherine. La roue et le stylo: Comment nous sommes devenus touristes. Paris, 1997.

Fridenson, Patrick. Histoire des usines Renault. Vol. 1: Naissance de la grande entreprise, 1898–1939. Paris, 1972.

Harp, Stephen L. Marketing Michelin: Advertising and Cultural Identity in Twentieth-Century France. Baltimore, Md., 2001.

Haubner, Barbara. Nervenkitzel und Freizeitvergnügen: Automobilismus in Deutschland, 1886–1914. Göttingen, 1998.

Laux, James M. In First Gear: The French Automobile Industry to 1914. Liverpool, U.K., 1976.

O'Connell, Sean. The Car and British Society: Class, Gender, and Motoring, 1896–1939. Manchester, U.K., 1998.

Stephen L. Harp

Encyclopedia of Modern Europe: Europe 1789-1914: Encyclopedia of the Age of Industry and Empire

Automobile

views updated May 23 2018

Automobile

The development of the automobile at the end of the nineteenth century fundamentally changed the structure of society in the developed world and has had wide-ranging effects on the environment , the most notable being the increase of air pollution in cities. The piston-type internal combustion engine is responsible for the peculiar mix of pollutants that it generates. There are a range of other engines suitable for automobiles, but they have yet to displace engines using rather volatile petroleum derivatives.

The simplest and most successful way of improving gaseous emissions from automobiles is to find alternative fuels. Diesel fuels have always been popular for larger vehicles, although a few private vehicles in Europe are also diesel-powered. Compressed natural gases have been widely used as fuel in some countries (e.g., New Zealand), while ethanol has had a limited success in places such as Brazil, where it can be produced relatively cheaply from sugar cane. There is some enthusiasm for the use of methanol in the United States, but it has yet to be seen if this will be widely adopted as a fuel.

Others have suggested that fundamental changes to the engine itself can lower the impact of automobiles on air quality . The Wankel rotary engine is a promising power source that offers both low vibration and pollutant emissions from a relatively lightweight engine. Although Wankel engines are found on a number of exotic cars, there are still doubts about long-term engine performance and durability in the urban setting. Steam and gas turbines have many of the advantages of the Wankel engine, but questions of their expense and suitability for automobiles have restricted their use. Electric vehicles have had some impact for special sectors of the market. They have proved ideal for small vehicles within cities where frequent stop-start operation is required (e.g., delivery vans). A few small, one-seat vehicles have been available at times, but they have failed to achieve any enduring popularity. The electric vehicle suffers from low range, low speed and acceleration, and needs heavy batteries. However these vehicles produce none of the conventional combustion-derived pollutants during operation, although the electricity to recharge the batteries requires the use of an electricity generating station. Still, electricity generation can be sited away from the urban center and employ air pollution controls. Fuel cells are an alternate source of electricity for electric automobiles. It is also possible to power automobiles through the use of flywheels. These are driven up to high speeds by a fixed, probably electric, motor, then the vehicle can be detached and powered using the stored momentum, although range is often limited.

Although automobile emissions are of great concern, the automobile has a far wider range of environmental impacts. Large amounts of material are used in their construction, and discarded automobiles can litter the countryside and fill waste dumps. Through much of the twentieth century the vehicles have been made of steel. Increasingly, other materials, such as plastics and fiberglass, are used as construction materials. A number of projects, most frequently on the European continent, have tried recycling automobile components. Responsible automobile manufacturers are aiming to build vehicles with longer road lives, further aiding waste reduction .

The high speeds now possible for automobiles lead to sometimes horrendous accidents, which can involve many vehicles on crowded highways. The number of accidents have been reduced through anti-lock braking systems, thoughtful road design, and imposing harsh penalties for drunk driving. In the future, on-board radar may give warning of impending collisions. Safety features such as seat belts, padding, and collapsible steering columns have helped lower injury during accidents.

The structure of cities has changed with widespread automobile ownership. It has meant that people can live further away from where they work or shop. The need for parking has led to the development of huge parking lots within the inner city. Reaction to crowding in city centers are seen in the construction of huge shopping centers outof-town, where parking is more convenient (or strip development of large stores along highways). These effects have often caused damage to inner city life and disenfranchised non-car owners, particularly because a high proportion of car ownership often works against the operation of an effective mass transit system. For people who live near busy roads, noise pollution can be a great nuisance. The countryside has also been transformed by the need for super highways that cope with a large and rapid traffic flow. Such highways have often been built on valuable agricultural land or natural habitats, and once constructed, create both practical and aesthetic nuisances.

[Peter Brimblecombe ]

RESOURCES

BOOKS

Environmental Effects of Automotive Emissions. Paris: OECD Compass Project, 1986.

Environmental Encyclopedia Brimblecombe, Peter

automobile

views updated May 17 2018

automobile Road vehicle that first appeared in the 19th century. The first cars were propelled by steam, but were not a success. The age of the motor car really dates from the introduction (1885–86) of the petrol-driven carriages of Gottlieb Daimler and Karl Benz. The internal combustion engine for these cars had been developed earlier by several engineers (most notably Nikolaus Otto in 1876). The main components of a motor car remain unchanged. A body (chassis) to which are attached all other parts including: an engine or power plant; a transmission system for transferring the drive to the wheels, and steering, braking and suspension for guiding, stopping and supporting the car. Early cars were assembled by a few experts, but modern mass-production began in the early 1900s with Henry Ford and R. E. Olds in the USA. In most modern motor factories, component parts are put together on assembly lines. Each worker has a specific task (such as fitting doors or crankshafts). Bodies and engines are made on separate assembly lines which converge when the engine is installed. Overhead rail conveyors move heavy components along the assembly lines, lowering them into position. The final stages of assembly include the fitting of items such as lamps and paint spraying. Electrical, braking and control systems are checked. The assembled car is tested before sale. Recent technology has seen the introduction of robots (properly, robotic arms secured to the workshop floor) on the assembly line. They are usually used for welding and painting. Increasing concern over the environmental impact of the car (such as congestion, pollution, and energy consumption) has encouraged governments to examine alternative forms of mass transport, oil companies to produce cleaner fuels, and car manufacturers to look at alternative power plants (such as electric- or gas-powered motors).

World Encyclopedia

automobile

views updated May 29 2018

au·to·mo·bile / ˌôtəmōˈbēl/ • n. a road vehicle, typically with four wheels, powered by an internal combustion engine or electric motor and able to carry a small number of people.

The Oxford Pocket Dictionary of Current English

automobile

views updated Jun 11 2018

automobile adj.; self-propelling; sb. (chiefly U.S.) motor-car. XIX. — F.; see AUTO-, MOBILE.

The Concise Oxford Dictionary of English Etymology T. F. HOAD

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