汽车排气系统外文翻译

汽车排气系统外文翻译 Automobile emissions control covers all the technologies that are employed to reduce the air pollution-causing emissions produced by automobiles. Exhaust emissions control systems were first required on 1966 model year vehicles produced for sale in the state of California, followed by the United States as a whole in model year 1968. the overall reduction in pollution has been much slower. The emissions produced by a vehicle fall into three basic categories: Tailpipe emissions: This is what most people think of when they think of vehicle air pollution; the products of burning fuel in the vehicle's engine, emitted from the vehicle's exhaust system. The major pollutants emitted include: Hydrocarbons: this class is made up of unburned or partially burned fuel, and is a major contributor to urban smog, as well as being toxic. They can cause liver damage and even cancer. Nitrogen oxides (NOx): These are generated when nitrogen in the air reacts with oxygen under the high temperature and pressure conditions inside the engine. NOx emissions contribute to both smog and acid rain. Carbon monoxide (CO): a product of incomplete combustion, carbon monoxide reduces the blood's ability to carry oxygen and is dangerous to people with heart disease. Carbon dioxide (CO2): Emissions of carbon dioxide are an increasing concern as its role in global warming as a greenhouse gas has become more apparent. Particulates. Particle of micron size. Sulphur oxide (SOx) General term for oxides of sulphur, mostly sulfur dioxide and some sulfur trioxide, from coal or unrefined oil. Tailpipe emissions control Tailpipe emissions control can be categorised into three parts: Increasing engine efficiency Increasing vehicle efficiency Cleaning up the emissions Increasing engine efficiency Engine efficiency has been gradually improved with progress in following technologies: Electronic ignition Fuel injection systems Electronic control unit Increasing vehicle efficiency Contributions to the goal of reducing fuel consumption and related emissions come from lightweight vehicle design minimized air resistance reduced rolling resistance improved powertrain efficiency increasing spark to the spark plug (this topic should be under the ignition system) regenerative braking Each of these items breaks down into a number of factors. Increasing driving efficiency Significant reduction of emissions come from driving technique (some 10-30% reduction) unobstructed traffic conditions cruising at an optimum speed for the vehicle reducing the number of cold starts Cleaning up the emissions Advances in engine and vehicle technology continually reduce the amount of pollutants generated, but this is generally considered insufficient to meet emissions goals. Therefore, technologies to react with and clean up the remaining emissions have long been an essential part of emissions control. Air injection A very early emissions control system, the Air injection reactor (AIR) reduces the products of incomplete combustion (hydrocarbons and carbon monoxide) by injecting fresh air into the exhaust manifolds of the engine. In the presence of this oxygen-laden air, further combustion occurs in the manifold and exhaust pipe. Generally the air is delivered through an engine-driven 'smog pump' and air tubing to the manifolds. Exhaust Gas Recirculation Many engines produced after the 1973 model year have an exhaust gas recirculation valve between the exhaust and intake manifolds; its sole purpose is to reduce NOx emissions by introducing exhaust gases into the air/fuel mixture, lowering peak combustion temperatures. Catalytic converters The catalytic converter is a device, placed in the exhaust pipe, which converts various emissions into less harmful ones using, generally, a combination of platinum, palladium and rhodium as catalysts.They make for a significant, and easily applied, method for reducing tailpipe emissions. The lead emissions were highly damaging to human health, and its virtual elimination has been one of the most successful reductions in air pollution. Evaporative emissions control Efforts at the reduction of evaporative emissions include the capturing of vented vapors from within the vehicle, and the reduction of refuelling emissions. Capturing vented vapors Within the vehicle, vapors from the fuel tank are channelled through canisters containing activated carbon instead of being vented to the atmosphere. These are known as carbon canisters. The vapors are adsorbed within the canister, which feeds into the inlet manifold of the engine. Emission Testing In 1966, the first emission test cycle was enacted in the State of California measuring tailpipe emissions in PPM (parts per million). The Environmental Working Group used California ASM emissions data to create an Auto Asthma Index that rates vehicle models based on emissions of hydrocarbons and nitrogen oxides, the chemicals that create smog. Some cities are also using a technology developed by Dr. Stedman,of University of Denver which uses lasers to detect emissions while vehicles pass by on public roads, thus eliminating the need for owners to go to a test center. Stedman's laser detection of exhaust gases is commonly used in metropolitan areas. ----------------------------------------- Emission control systems in automotive applications can trace their beginnings to the smoggy skies that were noted over the city of Los Angeles after the end of World War II. There were of course cars before the war and air pollution problems as a result of the activities of steelmaking, oil refining, and coal burning power plants were well known by then. Air Pollution in those days was for the most part written off as the price of progress, but as automobiles streamed onto the nation's ever-expanding highway system in unprecedented numbers in the 1950s, the pollution problems caused by their use, along with pollution caused by industrial sources could no longer be dismissed as an annoyance. Tailpipe emissions from automobiles fall into 5 major categories: Unburned Hydrocarbons Oxides of Nitrogen Carbon Monoxide Sulfur Dioxide Compounds of Lead In addition, automobiles also generate several secondary sources of pollution. These Include: Evaporative Emissions from fuel vapors, which find their way into the air Water pollution, from fluids that leak from cooling systems, engines, and transmissions. Hazardous Waste from discarded fluids, tires, batteries, and the like. Asbestos fibers from brake linings and clutches. A bit about the nature of automotive air pollutants Unburned Hydrocarbons are the result of incomplete combustion of fuel in an engine. Theoretically, if an engine burns its fuel perfectly, there should be little or no unburned hydrocarbons. Skipping all the chemistry equations, if there is one part gasoline vapor by volume to 15 parts air, the fuel should burn perfectly, producing only carbon dioxide and water vapor as byproducts. In practice, this is difficult to do with a carbureted engine operating over a wide variety of temperatures, fuel formulations, and load conditions. Blowby, which is combustion gasses escaping past piston rings (or Apex Seals for you Wankel buffs) is also a major source of unburned hydrocarbons. Carbon Monoxide is formed when combustion takes place when there is a shortage of oxygen. Carbon Monoxide wants to be Carbon Dioxide, but can't find another oxygen atom combine with. This makes it very reactive, and will bind with Hemoglobin, rendering it useless to transport oxygen in the blood. Small amounts of breathed CO cause headaches and fatigue, but Carbon Monoxide can kill if breathed in large enough amounts. In the Steel industry, Carbon Monoxide is used to pull the oxygen out of Iron Oxide to form pure Iron, but it is bad news in your bloodstream. CO can form in large amounts if too much fuel is allowed into the cylinders, or there are pockets of too rich a fuel-air mixture in the cylinders. Oxides of Nitrogen form Smog when exposed to sunlight, and form when combustion temperatures exceed 2,300 F, forcing Oxygen and atmospheric Nitrogen (N2) to combine in a sort of chemical shotgun wedding. Like the human kind of shotgun weddings, these types of bonds are unstable and form reactive compounds under the right conditions. They form when preignition occurs, but also form under conditions of normal operation as well, particularly in high performance applications. Sulfur Dioxide is a byproduct of burning sulfur, a common impurity in many fuels. Sulfur Dioxide can combine with water to form Sulfuric Acid, a very corrosive chemical which can corrode metals, etch paint, and render lakes too acid to support aquatic life. Control primarily consists of removing sulfur from fuel at the refinery. A Timeline of Automotive Emission Controls 1966: California implements the first emissions standards in the nation. Early emission controls consisted of a PCV Valve, which provided positive crankcase ventilation while routing blowby gasses back into the air intake to be reburned in the engine. This was a great help in reducing emissions from unburned hydrocarbons, but did little to reduce Nitrogen Oxide emissions or Carbon Monoxide emissions. California cars also got fixed high-speed carburetor jets, and saw other tweaks to engine tuning to reduce other emissions. California, then and now served as a laboratory for nationwide deployment for more advanced emission controls. 1968: Emission Controls were implemented Nationwide Nationwide crankcase emission controls were implemented in new cars, and were similar to 1966 California cars. Light Trucks started to get emission controls a few years later. For a long time, emission standards for light trucks tended to lag those of automobiles, but the gap has narrowed over time. Air injection was introduced into California vehicles, in an effort to reduce CO and Unburned Hydrocarbons. 1969-1971: A gradual tightening of standards: Compression ratios were dropped to reduce Nox emissions, and carburetion was leaned out to lower CO and HC emissions. This was the beginning of the end of the muscle car, at least in its original raw form. Air Injection and Exhaust Gas Recirculation made its way into more vehicles. 1971: The Clean Air Act was passed The Clean Air Act mandated drastic reductions in emissions over the next decade. The Clean air Act also mandated the eventual removal of tetraethyl lead from automotive fuels. Detroit's Big Three howled in protest, complaining that the new standards at best would be hugely expensive, or impossible to meet. In the automaker's research and development laboratories, a number of approaches were developed, and were the forerunner of modern emission controls. Ford had a program called Programmed Combustion, Honda developed the Stratified Charge Engine, and technologies such as electronically controlled carburetors, electronic ignition, catalytic converters, and the beginnings of computerized engine management systems were developed over the next several years. 1972 to 1975: Emission Controls and the Energy Crisis take a bite out of Detroit The early to mid `70s were the darkest years for Detroit. Work on new technologies was feverishly going on in the lab and on the test track. What found its way into the average car however, was lowered compression ratios to allow operation on 87 octane unleaded gas, lean tuning to reduce unburned hydrocarbons, air injection, and exhaust gas recirculation to reduce peak combustion temperatures. An energy crisis followed the arab oil embargo of 1973, forcing gas prices up and prompted implementation of the much hated 55 mph speed limit in the United States. American cars of this era for the most part ran terribly, hobbled by lean tuning, low compression ratios, and an increasingly crowded engine compartment featuring a rats nest of new plumbing and wiring. They ran even worse when these quickly designed systems became balky. Stalling and hesitation were common problems, and people forced to drive them often resorted to removing emission controls in an attempt to restore some driveability. Emission controls of the time had a negative effect on fuel economy, aggravating an already bad fuel supply situation. 1975 saw the widespread introduction of the Catalytic Converter, which allowed automakers to restore at least some driveability to their offerings, but performance was still a shadow of its late 1960s levels. An informal comparison of vehicles our family owned during the late `70s shows how much performance dropped. We owned a 1970 Chrysler Town and Country with a 383 cubic inch engine with a 2-barrel carburetor, which would run on regular gas. It got about 13 mpg around town, 17 on the highway, and had a top speed of about 110 miles per hour, even loaded to the roof. We also had a 1976 Ford LTD Wagon with a 400 cubic inch engine and a 2-barrel carburetor, and in most other respects they were very similar cars. The LTD got 10 mpg around town, 14 on the highway, and had a top speed of barely 100 mph. As performance dropped through the `70s, carmakers also limited the top indicated speed on the speedometer to 85 mph on most cars. Performance became a four letter word, and instead automakers chose to emphasise styling and accessories in their large cars, and fuel economy in their smaller models. 1976-1980: Downsizing and the introduction of electronics under the hood The dark years for Detroit continued, though sales perked up for a while as gas prices stabilized from 1975 through 1978. Detroit engineers also faced the challenge of improving the fuel economy of their fleets, while also meeting stricter safety standards. General Motors trimmed nearly 1,000 pounds and about 100 cubic inches from their full size cars. Ford's new LTD in 1979 looked suspiciously like their old Ford Fairmont, a much smaller vehicle. The new "premium" LTD Landau was still over a foot shorter, and had an engine 100 cubic inches smaller than the 1978 model. Catalytic Converters, combined with air pumps, exhaust gas recirculation, lean tuning, and electronic ignition on most vehicles allowed most cars to meet increasingly strict emissions standards, but many of the larger engines could not meet the newer standards. The second energy crisis in 1979, combined with emissions problems with many larger V8 engines made engines over 400 cubic inches nearly extinct by the end of the decade, except in the Cadillac Sedan de Ville and 3/4 ton and larger pickups. Technology by the end of the 1970s for most vehicles made in North America consisted of Catalytic Converters, combined with air pumps, exhaust gas recirculation, lean tuning, and electronic ignition on most vehicles. The end of the decade also saw the beginning of electronic engine management systems. My 1978 Plymouth Horizon had a spark control computer to control ignition timing and my brother's 1979 Plymouth Horizon TC3 had an electronically controlled carburetor in addition to the ignition timing. Overseas, emissions standards were getting stiffer as well, particularly in Western Europe and Japan. Honda, Mercedes-Benz, and Volkswagen were able to meet US and even California emissions standards without needing a catalytic converter. Diesel Engines and other technologies Mercedes-Benz and Volkswagen were able to meet the standards for emissions by using diesel engines in their cars. Diesel Engines tend to produce pretty low emissions without extra equipment, though they do produce a fair amount of soot which was not a pollutant of concern at the time. Diesel Engines also allowed for greater fuel efficiency, a Volkswagen Rabbit Diesel was able to get nearly 50 miles a gallon, at the time. Mercedes Benz had built diesel vehicles since the `30s, and by the late `70s, they had developed an almost legendary reputation for design, durability, and fuel economy as well. A late `70s 240D got 25 miles per gallon, not bad considering that a similarly sized American car of the time got about 17 mpg. General Motors got into the diesel act in 1978 with a diesel engine option in full-sized Oldsmobiles, Buicks, and Cadillacs. A 4 cylinder diesel Chevette was also sold for a few years as well, which got nearly 50 mpg. In the fuel-starved days of 1980, they were a popular option, despite their slower acceleration, noise, and $1,000 premium compared to the gasoline powered model. What the buyer got in return was a full-sized car that got nearly 30 miles per gallon on the highway. What the buyer didn't get was an engine designed from the ground up as a diesel, but a converted gasoline engine based on the proven 350 cubic inch small-block V8. Diesel Engines operate at very high compression ratios, up to 22 to 1, and the extreme stresses placed on the engine internals caused many of these engines to self-destruct before they even had 50,000 miles on them. If the engines had managed to get a diet of high-quality fuel, the stiffened internals of the GM Diesels compared to their gasoline counterparts would have been adequate to hold up. The root of the problem turned out to be the fact that the injector pumps corroded from exposure to moisture and acids present in the poor quality of diesel fuel commonly available at the time, combined with an inadequate filtration system to remove these impurities. A damaged injector pump would cause improper timing and amount of fuel to be injected, causing the cylinder pressures to go sky-high eventually blowing the head gasket. Once the head gasket blew, it usually didn't take long for the rest of the engine to self-destruct. General Motors had to replace many of these engines under warranty, and within 5 years the diesel engine option was dropped. Regrettably this gave not only GM a black eye, but gave diesel engines as viable automobile powerplants a black eye as well, at least in the eyes of most Americans. Diesels gained wider acceptance as alternatives to big-block V8 gasoline engines in medium duty trucks, delivery vehicles, and school busses, but have not seen a rebirth in domestic cars, though they outnumber gasoline cars in Western Europe today. Honda was able to meet 1975 standards by use of a novel gasoline engine called a Stratified Charge Engine, which Honda dubbed the CVCC. The engine featured a cylinder head with 3 valves per cylinder, and a special carburetor. The carburetor featured a main section which provided a lean fuel-air mixture for most of the volume in the cylinder, and a section which provided a richer mixture in the area near the spark plug. The enriched layer of mixture ensured reliable ignition, while the main charge was lean enough to suppress formation of unburned hydrocarbons, oxides of Nitrogen and Carbon Monoxide. The carefully designed combustion chamber promoted swirling combustion, which ensured complete burning of the fuel-air mix. Honda was able to avoid putting Catalytic Converters on their vehicles until well into the 1980s. 汽车排放控制涵盖所有技术,用来减少空气pollution-causing由汽车所排放的废气。 废气排放控制系统首先需要在1966年生产的汽车在加州销售,紧随其后的是美国在1968年作为一个整体。 整体减少污染已慢得多。 汽车产生的排放分为三个基本类别: 一.尾气排放:这就是大多数人认为当他们认为汽车的空气污染;产品燃烧燃料的汽车的引擎,发出汽车的排气系统。 排放的主要污染物包括:碳氢化合物:这个类是由未燃的或部分燃烧燃料,导致城市烟雾的主要因素,也是有毒的。 他们甚至会导致肝损伤和癌症;生成氮氧化物(NO):这些是当空气中的氮气与氧气在高温高压的条件下反应在引擎。 氮氧化物的排放x 导致烟雾和酸雨;一氧化碳(CO):不完全燃烧的产物,一氧化碳会降低血液携带氧气的能力,是很危险的心脏病患者;二氧化碳(CO):二氧化碳的排放也越来越关注全球变暖的影响作为2 温室气体已变得更为明显;微粒:微米大小的颗粒;硫氧化物(SO)通用术语硫氧化物主要x 是二氧化硫和三氧化硫,从煤或未经提炼的油。 二.尾气排放控制 尾气排放控制可分为三个部分:1提高发动机效率 2提高车辆效率 3清理排放 (1)提高发动机效率:引擎效率逐渐提高与进步在以下技术:电子点火;燃油喷射系统;电子控制单元 (2)提高车辆效率:贡献减少燃料消耗和相关排放的目标 轻型汽车设计:减少空气阻力、减少滚动阻力、提高传动系统效率、增加火花火花塞、再生制动，每一个项目分解成一系列的因素。 提高传动效率，显著减少排放 驾驶技术(一些减少10 - 30%) 畅通无阻的交通状况，巡航速度最佳的车辆，减少冷启动 (3)清理排放 发动机和汽车技术的进步不断地减少污染物的生成,但这是通常被认为是不足以满足排放目标。 因此,技术反应和清理剩下的排放一直排放控制的一个重要组成部分。 空气喷射 很早的排放控制系统,空气注入反应堆(空气)减少了产品的不完全燃烧(碳氢化合物和一氧化碳)注入新鲜空气发动机的废气再循环系统。 在这个携氧的空气的存在,进一步燃烧发生在管汇和排气管。 一般空气通过一个机动的烟雾泵和空气管阀组。 废气再循环装置 许多发动机生产在1973年以后有一个废气再循环阀排气和进气歧管之间,它的唯一目的是减少氮氧化物排放废气引入的空气/燃料混合物,降低燃烧温度峰值。 催化转换器 催化转化器是一种设备,放置在排气管,将各种排放转化为更少的有害的使用,一般来说,铂、钯和铑催化剂。 他们成为一个重要的、容易应用,减少尾气排放的方法。 铅排放高度损害 人体健康,及其虚拟消除一直是最成功的减少空气污染。 蒸发排放控制 努力减少蒸发排放包括从汽车中排放蒸汽的捕获,并减少加油排放。 捕捉排放气体 在汽车内,蒸汽从燃料箱通过包含活性炭罐,而不是排放到大气中。 这些被称为碳罐。 内的蒸气吸附罐,这加剧了发动机的进气歧管。 排放测试 1966年,颁布了第一个发射测试周期在加州测量尾气排放PPM(百万分之)。 环境工作小组使用加州ASM排放数据创建一个汽车哮喘指数利率汽车模型基于碳氢化合物和氮氧化物的排放,产生烟雾的化学物质。 一些城市也使用Stedman博士开发的技术,利用激光来检测排放的丹佛大学虽然在公路上车辆经过,因此不再需要老板去测试中心。 Stedman激光探测的废气是常用的在大都市地区。 汽车排放控制系统应用程序的开始可以追溯到到烟雾弥漫的天空,指出在城市洛杉矶二战结束后。 当然有汽车在战争和空气污染问题作为炼钢的活动结果,炼油,燃煤电厂是众所周知的。 空气污染在那些日子是在大多数情况下是进步的价格,但随着汽车倾泻到国家的不断扩张的高速公路系统达到前所未有的数量在1950年代,其使用造成的污染问题以及造成污染的工业来源可能不再被视为一个烦恼。 从汽车尾气排放分为5大类: 燃烧的碳氢化合物 氮的氧化物 一氧化碳 二氧化硫 铅化合物 此外,汽车也产生一些二次污染源。 这些包括: 燃油蒸发排放蒸汽,发现他们的方式到空气中 水污染,从泄漏的液体冷却系统,发动机和变速器。 从废弃液体危险废物、轮胎、电池等。 石棉纤维刹车片和离合器。 一些关于汽车空气污染物的性质 燃烧的碳氢化合物的不完全燃烧的燃料引擎。 从理论上讲,如果一个引擎燃料完全燃烧,应该有很少或没有燃烧的碳氢化合物。 跳过所有的化学方程式,如果有一部分汽油蒸汽的体积 15部分空气,燃料燃烧完全,应该只生产二氧化碳和水蒸气作为副产品。 在实践中,这是很难与可燃引擎操作在各种温度、燃料配方和加载条件。 窜漏,燃烧气体逃离过去活塞环(或先端为你海豹汪克尔爱好者)也是一个燃烧的碳氢化合物的主要来源。 一氧化碳是燃烧时形成发生在缺乏氧气。 一氧化碳想成为二氧化碳,但找不到另一个氧原子结合。 这使它非常被动,将与血红蛋白结合,使其无用的血液中运输氧气。 少量的呼吸公司导致头痛和疲劳,但如果吸入一氧化碳可以杀死足够大的数量。 在钢铁行业,一氧化碳是用来把氧氧化铁形成纯铁,但它是一个坏消息在你的血液中。 公司可以形成大量是否允许太多的燃料进入气缸,或者有口袋太丰富的燃料空气混合物在气缸。 氮的氧化物形成烟雾暴露在阳光下时,并形成燃烧温度超过华氏2300度时,迫使氧和大气氮(N2)将一种化学先上车后补票的婚礼。 像人类的猎枪婚礼,这些类型的债券是不稳定,在合适的条件下形成活性化合物。 他们提前点火发生时形成,但也形成正常运行的条件下,特别是在高性能的应用程序。 二氧化硫是燃烧的副产品硫,一个常见的杂质在许多燃料。 二氧化硫与水结合形成硫酸,腐蚀性化学物质,能腐蚀金属,太酸腐蚀油漆,使湖泊水生生物的支持。 控制主要包括消除硫燃料的炼油厂。 汽车排放控制的时间 表 关于同志近三年现实表现材料材料类招标技术评分表图表与交易pdf视力表打印pdf用图表说话 pdf 1966:加州实现第一个国家排放 标准 excel标准偏差excel标准偏差函数exl标准差函数国标检验抽样标准表免费下载红头文件格式标准下载 。 早期的排放控制由PCV阀,曲轴箱强制通风,同时提供路由窜漏气体回进气reburned在引擎。 这是一个伟大的帮助在减少排放从你nburned碳氢化合物,但并没有减少氮氧化物的排放或一氧化碳的排放。 加州汽车也固定高速化油器飞机,看到其他调整引擎调优,以减少排放。 加州,然后,现在担任 实验室 17025实验室iso17025实验室认可实验室检查项目微生物实验室标识重点实验室计划 在全国范围内部署更先进的排放控制。 1968:排放控制在全国范围内实施 全国曲轴箱排放控制中实现新的汽车,和类似于1966年加州的汽车。 轻型卡车开始排放控制几年后。 很长一段时间,排放标准的轻型卡车往往落后于汽车,但差距已经缩小。 加州空气喷射被引入车辆,以减少公司和未燃的碳氢化合物。 1969 - 1971:逐步收紧标准: 压缩比是减少氮氧化物排放下降,与碳化合探出降低CO和HC排放。 这是结束的开始的肌肉车,至少在最初的原始形式。 空气注入和废气再循环进入了更多的车辆。 1971年:《清洁空气法案》获得通过 《清洁空气法》规定在未来十年排放数量的急剧减少。 《清洁空气法》也规定四乙铅的最终去除汽车燃料。 底特律的三大号啕大哭以示抗议,抱怨新标准在最好的将是非常昂贵的,或无法满足。 在汽车的研发实验室,许多方法被开发,现代排放控制的先驱。 福特一个叫做编程的程序燃烧,本田分层充气引擎开发,和技术如电控化油器、电子点火,催化转换器,计算机化的开端引擎管理系统开发在未来数年。 1972年至1975年:排放控制和能源危机咬了底特律 初到70年代中期为底特律最黑暗的年。 狂热地工作在新技术在实验室和测试记录。 然而,发现进入普通的汽车是降低压缩比,允许操作87辛烷值的无铅汽油,精益优化降低未燃的碳氢化合物,空气喷射,废气再循环减少燃烧峰值温度。 能源危机是1973年阿拉伯石油禁运,迫使天然气价格上涨,促使实现多讨厌55英里每小时的速度限制在美国。 这个时代的美国汽车大部分跑非常,因为精益优化,低压缩比,日益拥挤的机舱中老鼠窝新管道和布线。 他们更糟糕的是当这些快速设计系统成为倔强的。 拖延和犹豫是常见问题,人们不得不把他们经常采取消除排放控制,试图恢复一些驾驶性能。 排放控制的时间对燃油经济性产生了负面影响,加重一个已经坏的燃料供应情况。 1975年的广泛引入催化转换器,使得汽车制造商至少有一些驾驶性能恢复到他们的产品,但是它的性能仍然是一个影子1960年代末的水平。 一个非正式的车辆比较我们的家族在70年代末显示多少性能下降。 我们拥有1970年的城镇和乡村克莱斯勒383立方英寸2-barrel化油器发动机,这将运行在普通汽油。 它在城里约13英里/加仑,17在高速公路上,最高时速约为110英里每小时,甚至屋顶加载。 我们也有一个1976年的福特公司货车有400立方英寸的发动机和2-barrel化油器,和在其他方面他们非常相似的汽车。 有限公司在城里有10英里/加仑,14日在高速公路上,最高时速仅100英里。 由于性能下降在70年代,汽车制造商也有限的顶部显示速度85英里每小时的速度计在大多数汽车。 性能成为四字母词,而汽车制造商选择强调造型的大型车及配件,和燃油经济性的小模型。 1976 - 1980:裁员和引入电子 黑暗的年底特律继续,尽管销售活跃起来了一段时间从1975年到1978年天然气价格稳定。 底特律的 工程 路基工程安全技术交底工程项目施工成本控制工程量增项单年度零星工程技术标正投影法基本原理 师也面临的挑战,改善燃油经济性的舰队,同时会议更严格的安全标准。 通用汽车(General Motors)削减了近1000英镑,大约100立方英寸的全尺寸汽车。 1979年福特的新公司长相酷似老福特费尔蒙,一个小得多的车辆。 新的“溢价”有限公司朗道还在脚短,和有一个引擎100立方英寸小于1978模型。 催化转换器,加上空气泵、废气再循环、精益优化,和电子点火在大多数车辆允许大多数车辆满足日益严格的排放标准,但许多较大的引擎无法达到新标准。 第二个1979年的能源危机,加上许多较大的V8引擎发动机排放问题超过400立方英寸几乎灭绝的十年中,除了在凯迪拉克轿车德城镇和3/4吨大皮卡。 技术由1970年代末对大多数车辆在北美由催化转换器,加上气泵,废气再循环,精益的调优,在大多数汽车电子点火。 十年结束的时候还看到电子引擎管理系统的开始。 我1978年普利茅斯地平线有火花控制计算机控制点火正时和我哥哥的1979年普利茅斯地平线TC3有电控化油器除了点火时间。 海外,排放标准也会越来越激烈,尤其是在西欧和日本。 本田,奔驰,大众能够满足我们,甚至加州排放标准而无需催化转换器。 柴油发动机和其他技术 梅塞德斯-奔驰和大众能够满足排放标准在他们的汽车使用柴油发动机。 柴油发动机往往产生很低排放没有额外的设备,尽管他们产生大量的烟尘并没有关注的污染物。 柴油发动机还允许更大的燃油效率、大众兔子柴油能够得到近50英里每加仑,。 奔驰了柴油车自30年代,到了70年代,他们已经开发了一个几乎传奇的名声设计,耐用性和燃油经济性。 70年代后期240 d有25英里每加仑,不错,一个同样大小的美国汽车的时间有大约17英里/加仑。 通用汽车(General Motors)进入柴油法案在1978年与柴油发动机在全尺寸Oldsmobiles选项,别克,凯迪拉克轿车。 4缸柴油机Chevette也卖了几年,有近50英里/加仑。 1980年fuel-starved天,他们是一个受欢迎的选择,尽管他们慢加速,噪音,和1000美元溢价比汽油动力模型。 买方所得到的回报是一个全尺寸的汽车在高速公路上让近30英里每加仑。 买方没有得到什么是一个柴油发动机而设计的,但转换后的汽油发动机的基础上证明350立方英寸small-block V8。 柴油机运行在非常高的压缩比,22 - 1,极端的压力放在这些发动机的引擎内部引起了许多自我毁灭之前,他们甚至有50000英里。 如果发动机已设法让饮食优质燃料,加强内部的通用柴油比汽油同行就足够了。 问题的根源是,暴露于水分和注射器泵腐蚀酸存在于柴油常用的质量差,加上不足过滤系统去除这些杂质。 注射泵受损将导致不恰当的时机和数量的燃料注入,导致气缸压力最终天价去吹头垫片。 一旦头垫片吹,它通常没多久的发动机自毁。 通用汽车(General Motors)不得不替换这些引擎在保修期内,并在5年内柴油机选项是下降了。 遗憾的是这不仅给了通用一个黑色的眼睛,但柴油发动机作为可行的汽车发动机一个黑眼圈,至少在大多数美国人的眼睛。 柴油获得更广泛的接受替代big-block V8汽油发动机在中型卡车运载工具,和学校的公交车,但是还没有看到重生在国内汽车,尽管他们比汽油车今天在西欧。 本田是能够满足1975标准使用新颖的汽油发动机称为分层充气发动机,本田称为了CVCC。 发动机每缸汽缸与3阀门,和一个特殊的化油器。 化油器中一个主要部分,提供了一个具有精益燃气混合气缸的体积,和一节提供了一个丰富的混合物在火花塞附近的区域。 丰富的混合层确保可靠的点火,主要负责精益足以抑制燃烧的碳氢化合物的形成,氮氧化物和一氧化碳。 精心设计的提升旋转燃烧室燃烧,保证完全燃烧燃料空气混合。 本田可以避免给汽车催化转换器,直到到1980年代。