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.
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.
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.
See alsoAir Pollution ; American Automobile Association ; Automobile Industry ; Automobile Racing ; Automobile Safety ; Clean Air Act ; Gasoline Taxes ; Installment Buying, Selling, and Financing ; Interstate Highway System ; Japan, Relations with ; Mass Production ; National Labor Relations Act ; National Traffic and Motor Vehicle Safety Act ;Oil Crises ; Road Improvement Movements ; Roads ; Selden Patent .
"Automobile." Dictionary of American History. 2003. Encyclopedia.com. (September 30, 2016). http://www.encyclopedia.com/doc/1G2-3401800330.html
"Automobile." Dictionary of American History. 2003. Retrieved September 30, 2016 from Encyclopedia.com: http://www.encyclopedia.com/doc/1G2-3401800330.html
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.
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.
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.
- 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.
- 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.
- 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.
- 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.
- 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.
- 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.
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 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
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.
"The Secrets of the Production Line," The Economist. October 17, 1992, p. S5.
Bockmiller, Rick. "Automobile." How Products Are Made. 1994. Encyclopedia.com. (September 30, 2016). http://www.encyclopedia.com/doc/1G2-2896500015.html
Bockmiller, Rick. "Automobile." How Products Are Made. 1994. Retrieved September 30, 2016 from Encyclopedia.com: http://www.encyclopedia.com/doc/1G2-2896500015.html
automobile, self-propelled vehicle used for travel on land. The term is commonly applied to a four-wheeled vehicle designed to carry two to six passengers and a limited amount of cargo, as contrasted with a truck, which is designed primarily for the transportation of goods and is constructed with larger and heavier parts, or a bus (or omnibus or coach), which is a large public conveyance designed to carry a large number of passengers and sometimes additionally small amounts of cargo. For operation and technical features of automobiles, differential; fuel injection; ignition; internal-combustion engine; lubrication; muffler; odometer; shock absorber; speedometer; steering system; suspension; tachometer; tire; transmission.
Automobile Propulsion Systems
Reciprocating Internal-Combustion Engines
The modern automobile is usually driven by a water-cooled, piston-type internal-combustion engine, mounted in the front of the vehicle; its power may be transmitted either to the front wheels, to the rear wheels, or to all four wheels. Some automobiles use air-cooled engines, but these are generally less efficient than the liquid-cooled type. In some models the engine is carried just forward of the rear wheels; this arrangement, while wasteful of space, has the advantage of better weight distribution. Although passenger vehicles are usually gasoline fueled, diesel engines (which burn a heavier petroleum oil) are employed both for heavy vehicles, such as trucks and buses, and for a small number of family sedans. Both diesel and gasoline engines generally employ a four-stroke cycle.
The Wankel Engine
For some years, it was hoped that the Wankel engine, a rotary internal-combustion engine developed by Felix Wankel of Germany in 1954, might provide an alternative to the reciprocating internal-combustion engine because of its low exhaust emissions and feasibility for mass production. In this engine a three-sided rotor revolves within an epithrochoidal drum (combustion chamber) in which the free space contracts or expands as the rotor turns. Fuel is inhaled, compressed, and fired by the ignition system. The expanding gas turns the rotor and the spent gas is expelled. The Wankel engine has no valves, pistons, connecting rods, reciprocating parts, or crankshaft. It develops a high horsepower per cubic inch and per pound of engine weight, and it is essentially vibrationless, but its fuel consumption is higher than that of the conventional piston engine.
Alternative Fuels and Engines
Internal-combustion engines consume relatively high amounts of petroleum, and contribute heavily to air pollution; therefore, other types of fuels and nonconventional engines are being studied and developed. An alternative-fuel vehicle (AFV) is a dedicated flexible-fuel vehicle (one with a common fuel tank designed to run on varying blends of unleaded gasoline with either ethanol or methanol) or a dual-fuel vehicle (one designed to run on a combination of an alternative fuel and a conventional fuel) operating on at least one alternative fuel. An advanced-technology vehicle (ATV) combines a new engine, power train, and drive train system to significantly improve fuel economy. It is estimated that more than a half million alternative-fuel vehicles were in use in the United States in 2002; 50% of these operate on liquefied petroleum gas (LPG, or propane) and almost 25% use compressed natural gas (CNG).
The ideal alternative-fuel engine would burn fuel much more cleanly than conventional gasoline-powered internal-combustion engines and yet still be able to use the existing fuel infrastructure (i.e., gas stations). Compressed natural gas, propane, hydrogen, and alcohol-based substances (gasohol, ethanol, methanol, and other "neat" alcohols) all have their proponents. However, although these fuels burn somewhat cleaner than gasoline, the use of all of them involves trade-offs. For example, because they take up more space per mile driven, these alternatives require larger fuel capacities or shorter distances between refueling stops. In addition, conventional automobiles may require extensive modifications to use alternative fuels; for example, to use gasohol containing more than 17% ethanol, the spark plugs, engine timing, and seals of an automobile must be modified; since 1998, however, many U.S. automobiles have been manufactured with equipment that enables them to run on E85, a mixture of 85% ethanol and 15% gasoline. Fuels derived from plant materials, such as ethanol, are a popular concept because they do not deplete the world's oil reserves; in various locations, "biodiesel" test cars have run on fuel similar to sunflower-seed oil. Similarly, dual-fuel (gasoline-diesel and gasoline-propane) and water-fuel-emulsion cars are being tested.
Alternative propulsion systems are also being studied. Steam engines, which were once more common than gasoline engines, are being experimented with now because they give off fewer noxious emissions; they are, however, less efficient than internal-combustion engines. Battery-powered electric engines, used in some early automobilies and later mainly for local delivery vehicles, are now used in automobiles capable of highway speeds, but they are restricted to shorter trips because of limitations on the storage batteries that power the motors and the time required to recharge the batteries. A true mass-market all-electric automobile was first sold to consumers in late 2010.
Some engineers worry that widespread adoption of electric cars might actually generate more air pollution, because additional electric power plants would be needed to recharge their batteries. Therefore, design and research work has also intensified on solar batteries, but they are generally not yet powerful enough to power such vehicles. The most promising technology for electric engines is the fuel cell, but fuel cells currently are too expensive for practical applications.
Hybrid vehicles, or hybrid electric vehicles (HEVs), are powered by two or more energy sources, one of which is electricity, to produce a high-miles-per-gallon, low-emission drive. There are two types of HEVs, series and parallel. In a series hybrid, all of the vehicle power is provided from one source. For example, an electric motor drives the vehicle from the battery pack and the internal combustion engine powers a generator that charges the battery. In a parallel hybrid, power is delivered through both paths, both the electric motor and the internal combustion engine powering the vehicle. Thus, the electric motor may help power the vehicle while idling and during acceleration. The internal combustion engine takes over while cruising, powering the drive train and recharging the electric motor's battery. Some hybrids can operate in electric-only mode. Automobiles with gasoline-electric hybrid engines first appeared on the consumer market in 1999; unhampered by the AFV's limitations, sales of these vehicles increased steadily at the beginning of the 21st cent.
Automobiles and the Environment
Pollutants derived from automobile operation have begun to pose environmental problems of considerable magnitude. It has been calculated, for example, that 70% of the carbon monoxide, 45% of the nitrogen oxides, and 34% of the hydrocarbon pollution in the United States can be traced directly to automobile exhausts (see air pollution). In addition, rubber (which wears away from tires), motor oil, brake fluid, and other substances accumulate on roadways and are washed into streams, with effects nearly as serious as those of untreated sewage. A problem also exists in disposing of the automobiles themselves when they are no longer operable.
In an effort to improve the situation, the U.S. government has enacted regulations on the use of the constituents of automobile exhaust gas that are known to cause air pollution. These constituents fall roughly into three categories: hydrocarbons that pass through the engine unburned and escape from the crankcase; carbon monoxide, also a product of incomplete combustion; and nitrogen oxides, which are formed when nitrogen and oxygen are in contact at high temperatures. Besides their own toxic character, hydrocarbons and nitrogen oxides undergo reactions in the presence of sunlight to form noxious smog. Carbon monoxide and hydrocarbons are rather easily controlled by the use of high combustion temperatures, leaner fuel mixtures, and lower compression ratios in engines. Unfortunately, the conditions that produce minimum emission of hydrocarbons tend to raise emission of nitrogen oxides. To some extent this difficulty is solved by adding recycled exhaust gas to the fuel mixture, thus avoiding the oversupply of oxygen that favors formation of nitrogen oxides.
The introduction of catalytic converters in the exhaust system has provided a technique for safely burning off hydrocarbon and carbon-monoxide emissions. The fragility of the catalysts used in these systems required the elimination of lead compounds previously used in gasoline to prevent engine knock. California, which has the most stringent air-pollution laws in the United States, requires further special compounding of gasoline to control emissions, and several states have mandated that ethanol be mixed with gasoline; as with the elimination of lead, measures taken to control air pollution have a negative impact on fuel efficiency. In 2009 the United States adopted more stringent mileage and emission standards (effective in 2012 and based on California's standards), which were designed to produce the first significant increases in vehicle efficiency and decreases in vehicle pollution since the mid-1980s.
Fatalities due to automobile accidents have stimulated improvements in automotive safety design. The first innovation involves creating a heavy cage around the occupants of the automobile, while the front and rear of the car are constructed of lighter materials designed to absorb impact forces. The second safety system uses seat belts to hold occupants in place. This was largely ineffective until states in the United States began passing laws requiring seat belt use. The third system is the air bag; within a few hundredths of a second after a special sensor detects a collision, an air bag in the steering wheel or dashboard inflates to prevent direct human impact with the wheel, dashboard, or windshield (newer vehicles sometimes include side air bags, to protect occupants from side collisions). Other advances in vehicle safety include the keyless ignition, which makes it impossible for a driver to start a car while under the influence of alcohol (over half of all vehicle fatalities involve at least one driver who has used alcohol) and antilock braking systems, which prevent an automobile's wheels from locking during braking.
Development of the Automobile
The automobile has a long history. The French engineer Nicolas Joseph Cugnot built the first self-propelled vehicle (Paris, 1789), a heavy, three-wheeled, steam-driven carriage with a boiler that projected in front; its speed was c.3 mph (5 kph). In 1801 the British engineer Richard Trevithick also built a three-wheeled, steam-driven car; the engine drove the rear wheels. Development of the automobile was retarded for decades by over-regulation: speed was limited to 4 mph (6.4 kph) and until 1896 a person was required to walk in front of a self-propelled vehicle, carrying a red flag by day and a red lantern by night. The Stanley brothers of Massachusetts, the most well-known American manufacturers of steam-driven autos, produced their Stanley Steamers from 1897 until after World War I.
The development of the automobile was accelerated by the introduction of the internal-combustion engine. Probably the first vehicle of this type was the three-wheeled car built in 1885 by the engineer Karl Benz in Germany. Another German engineer, Gottlieb Daimler, built an improved internal-combustion engine c.1885. The Panhard car, introduced in France by the Daimler company in 1894, had many features of the modern car. In the United States, internal-combustion cars of the horseless buggy type were manufactured in the 1890s by Charles Duryea and J. Frank Duryea, Elwood Haynes, Henry Ford, Ransom E. Olds, and Alexander Winton. Many of the early engines had only one cylinder, with a chain-and-sprocket drive on wooden carriage wheels. The cars generally were open, accommodated two passengers, and were steered by a lever.
The free growth of the automobile industry in the early 20th cent. was threatened by the American inventor George Selden's patent, issued in 1895. Several early manufacturers licensed by Selden formed an association in 1903 and took over the patent in 1907. Henry Ford, the leader of a group of independent manufacturers who refused to acknowledge the patent, was engaged in litigation with Selden and the association from 1903 until 1911, when the U.S. Circuit Court of Appeals ruled that the patent, although valid, covered only the two-cycle engine; most cars, including Ford's, used a four-cycle engine. The mass production of automobiles that followed, and the later creation of highways linking cities to suburbs and region to region, transformed American landscape and society.
Since 2010 there has been an increased focus on developing a practical automobile in which a computerized driving system either greatly aids or completely replaces the human driver. Although the technology for an automated vehicle has been explored since the 1920s, real work on semiautonomous and autonomous vehicles did not progress until the 1980s and the development of microcomputers, and even then the technology was not commercially practical. In the early 21st cent. an increasing number of automobile manufacturers begin including automatic safety equipment that activates when the vehicle's computerized systems sense conditions such as impending vehicle instability or collision and takes measures, such as automated braking, to avoid crashes and passenger injury. Significant advances also have been made in the development of self-driving vehicles, a number of which have been road-tested successfully in public traffic since 2010. In some cases, autonomous driving capabilities have been incorporated into cars that are commercially available.
See D. L. Lewis and L. Goldstein, The Automobile and American Culture (1983); J. J. Flink, The Automobile Age (1988); B. Olsen and J. Cabadas, The American Auto Factory (2002); P. Wollen and J. Kerr, ed., Autopia (2003); S. Parissien, The Life of the Automobile (2014).
"automobile." The Columbia Encyclopedia, 6th ed.. 2016. Encyclopedia.com. (September 30, 2016). http://www.encyclopedia.com/doc/1E1-automob.html
"automobile." The Columbia Encyclopedia, 6th ed.. 2016. Retrieved September 30, 2016 from Encyclopedia.com: http://www.encyclopedia.com/doc/1E1-automob.html
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 ]
"Automobile." UXL Encyclopedia of Science. 2002. Encyclopedia.com. (September 30, 2016). http://www.encyclopedia.com/doc/1G2-3438100086.html
"Automobile." UXL Encyclopedia of Science. 2002. Retrieved September 30, 2016 from Encyclopedia.com: http://www.encyclopedia.com/doc/1G2-3438100086.html
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"automobile." World Encyclopedia. 2005. Retrieved September 30, 2016 from Encyclopedia.com: http://www.encyclopedia.com/doc/1O142-automobile.html
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.
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