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原  稿

A New Type Car -- Hybrid Electric Vehicle

With skyrocketing fuel prices and changes in weather patterns, many car manufacturers claimed to develop the kind of vehicles that will increase the mileage and reduce the emissions. Hybrid car is a kind of vehicle which can meet above requirements. A hybrid car features a small fuel-efficient gas engine combined with an electric motor that assists the engine.

The reasons of building such a complicated machine are twofold: to reduce tailpipe emissions and to improve mileage. Firstly, hybrid cars are good for the environment. They can reduce smog by 90 percent and they use far less gasoline than conventional cars. Meanwhile, hybrid cars burn less gasoline per mile, so they release fewer greenhouse gases. Secondly, hybrid cars are economical. Hybrid cars, which run on gas and electricity, can get up to 55 to 60 miles per gallon in city driving, while a typical SUV might use three times as much gas for the same distance! There are three reasons can mainly account for that: 1) Hybrid engines are much smaller than those on conventional cars. A hybrid car engine is to accommodate the 99% of driving time when a car is not going up hills or accelerating quickly. When extra acceleration power is needed, it relies on the battery to provide additional force. 2) Hybrid gasoline engine can shut off when the car is stopped and run off their electric motor and battery. 3) Hybrid cars often recover braking energy. Electric motors could take the lost kinetic energy in braking and use it to charge the battery. Furthermore, hybrids are better than all-electric cars because hybrid car batteries recharge as you drive so there is no need to plug in. Most electric cars need to be recharged every 50-100miles. Also, most electric cars cannot go faster than 50-60 mph, while hybrids can.

Hybrid cars bridge the gap between electric and gasoline-powered cars by traveling further and driving faster and hybrid gas-electric cars are proving to be a feasible alternative at a time of high gas prices. So, in my opinion, hybrid cars will have a bright future.

How Does Hybrid Electric Vehicle Work？

You probably own a gasoline or diesel-engine car. You may have heard of electric vehicles too. A hybrid vehicle or hybrid electric vehicle (HEV) is a combination of both. Hybrid vehicles utilize two or more sources of energy for propulsion. In the case of HEVs, a combustion engine and an electric motor are used.

How it works depends on the type of drive train it has. A hybrid vehicle can either have a parallel or series or parallel-series drive train.

Parallel Hybrid

The parallel hybrid car has a gas tank, a combustion engine, transmission, electric motor, and batteries.

A parallel hybrid is designed to run directly from either the combustion engine or the electric motor. It can run using both the engine and the motor. As a conventional vehicle, the parallel hybrid draws its power from the combustion engine which will then drive the transmission that turns the wheels. If it is using the electric motor, the car draws its power from the batteries. The energy from the batteries will then power the electric motor that drives the transmission and turns the wheel.

Both the combustion engine and the electric motor are used at the same time during quick acceleration, on steep ascend, or when either the engine or the motor needs additional boost.

Since the engine is directly connected to the wheels in a parallel drive train, it eliminates the inefficiency of converting mechanical energy into electrical energy and back. This makes a very effective vehicle to drive on the highway.

Series Hybrid

The series hybrid car also has a gas tank, a combustion engine, transmission, electric motor, and batteries with the addition of the generator. The generator can be the electric motor or it can be another separate component.

The series configuration is the simplest among the 3. The engine is not connected to the transmission rather it is connected to the electric motor. This means that the transmission can be driven only by the electric motor which draws its energy from the battery pack, the engine or the generator.

A hybrid car with a series drive train is more suited for city driving conditions since the engine will not be subjected to the varying speed demands (stop, go, and idle) that contributes to fuel consumption.

Series-Parallel Hybrid

The series-parallel configuration solves the individual problems of the parallel and series hybrid. By combining the 2 designs, the transmission can be directly connected to the engine or can be separated for optimum fuel consumption. The Toyota Prius and the Ford Escape Hybrid use this technology.

Honda’s hybrid

For those of you who have toyed with the idea of buying a hybrid but were discouraged by the price, you are not alone. In fact, despite the growing concern for the environment, not to mention the skyrocketing price of gas, hybrid cars still only represent a small percentage of global car sales, and a major reason for this is the cost.  

Hybrids are considered the wave of the future because they not only reduce emissions, addressing the issue of climate change, but they get great gas mileage, an important consideration with the current price of oil. It should be noted that hybrids can also improve the power of the engine, which compromises any advantages in fuel efficiency and emissions. Whatever the application, however, the technology makes the cars more expensive.

Because of this, they are the vehicle of choice for only a small niche of people who can afford them, and they currently enjoy a special status amongst the image conscious celebrity-set. For most average consumers, however, they are not an option.

That may soon change.

Honda Motor Corporation, one of the largest car manufacturers in the world and a leader in fuel efficient technology, has unveiled it’s plan to introduce a low-cost hybrid by 2009. If they can pull it off, they hope to make the hybrid a more mainstream car that will be more appealing to the general public, with the ultimate goal of achieving greater sales and broader appeal than their current incarnation.

This, of course, is making Detroit nervous, and may signal a need for American car makers to start making greener and more fuel efficient vehicles, something they could afford to ignore in the past because hybrid cars weren’t worth their attention (due to such a small market share) while gas-guzzling SUVs have such high profit margins.

Honda, meanwhile, has had to confront a growing need to compete with Toyota, which has not only grown to be the world’s largest automaker, but makes the car that has become synonymous with the hybrid movement, the Prius. Honda is therefore faced with the seemingly insurmountable task of challenging Toyota’s dominance in the market.

Concurrently, Toyota is racing to lower production costs on the Prius, as well, which would hopefully result in a lower cost to the consumer. All eyes are on a potentially favorable car buyers market in 2009.

In the meantime, with even adamant global warming naysayers warming up (no pun intended) to the possibilities of an ecological disaster on the horizon, maybe it’s time that we got over our need to drive huge SUVs and start moderating our fuel consumption.

Then again, as gas prices hovering around $4.00 and with no ceiling in sight, we may have little choice in the matter.

Engine Operating Principles

Most automobile dngines are internal combustion, reciprocating 4-stroke gasoline engines, but other types have been used, including the diesel, the rotary ( Wankel ) , the 2-srtoke, and stratified charge.

Reciprocating means up and down or banck and forth, It is the up and down action of a piston in the cylinder blick, or engine block. The blick is an iron or aluminum casting that contains engine cylinders and passges called water jackets for coolant circulation. The top of the block is covered with the cylinder head. Which forms the combustion chanber. The bottom of the block is covered with an oil pan or oil sump.

Power is produced by the linear motion of a piston in a cylinder. However, this linear motion must be changed into rotary motion to turn the wheels of cars of trucks. The piston is attached to the top of a connecting rod by a pin, called a piston pin or wrist pin. The bottom of the connecting rod is attached to the crankshaft. The connecting rod transmits the up-and-down motion of the piston to the crankshaft, which changes it into rotary motion.

The connecting rod is mounted on the crankshaft with large beaings called rod bearings. Similar bearings, called main bearings, are used to mount the crankshaft in the block. Shown in Fig. 1-1

The diameter of the cylinder is called the engine bore. Displacement and compression ratio are two frequently used engine specifications. Displacement indicates engine size, and compression ratio compares the total cylinder volume to compression chamber volume.

The term stroke is used to describe the movement of the iston within the cylinder, as well as the distance of piston travel. Depending on the type of engine the operating cycle may require either two or four strokes to complete. The 4-stroke engine is also called Otto cycle engine, in honor of the German engineer, Dr. Nikolaus Otto, who first applied the principle in 1876. In the 4-stroke engine, four strokes of the piston in the cylinder are required to complete one full operating cycle. Each stroke is named after the action it performs intake, compression, power, and exhaust in that order, shown in Fig1-2.

1、Intake stroke

As the piston moves down, the vaporized mixture of fuel and air enters the cylinder through open intake valve. To obtain the maximum filling of the cylinder the intake valve opens about 10°before t.b.c., giving 20°overlap. The inlet valve remains open until some 50°after b.d.c. to take advantage of incoming mixture.

2、 Compression stroke

The piston turns up, the intake valve closes, the mixture is compressed within the combustion chamber, while the pressure rise to about 1Mpa, depending on various factors including the compression ratio, throttle opening and engine speed. Near the top of the stroke the mixture is ignited by a spark which bridges the gap of the spark plug.

3、 Power stroke

The expanding gases of combustion produces a rise in pressure of the gas to some 3.5Mpa, and the piston is forced down in the cylinder. The exhaust valve opens near the bottom of the stroke.

4、Exhust stroke

The piston moves back up with the exhaust valve open some 50°before b.d.d., allowing the pressure within the cylinder to fall and to reduce ‘back’pressure on the piston during the exhaust stroke, and the burned gases are pushed out to prepare for the next intake stroke.The intake valve usually opens just before the exhaust stroke.

This 4-stroke cycle is continuously repeared in every as long as the engineremains running.

A 2-stroke engine also goes through four actions to complete one operating cycle.

However, the intake and the compression actions are combined in one seroke, and the power and exhaust actions are combined in the other stroke. The term2-stroke cycle or 2-stroke is preferred to the term 2-cycle, which is really not accurate.

In automobile engines, all pistons are attached to a single crankshaft. The more cylinders an engine has, the more power strokes produced for cach revolution. This means that an 8-cylinder engine runs more smoothly bdcause the power atrokes are closer together in time and in degrees of engine rotation.

The cylinders of multi-cylinder automotive engines arranged in one of three ways.

1、Inline engines use a single block of cylinder.Most 4-cylinder and any 6-cylinder engines are of this design. The cylinders do not have to be vertical. They can be inclined either side.

2、V-type engines use two equal bands of cylinders, usually inclined 60degrees or 90degrees from the cach other. Most V-type engines have 6 or 8 cylinders, although V-4 and V-12 engines have been built.

3、Horizontally opposed or pancake engines have two equal banks of cylinders 180degreeas apart. These space saving engine designs are often air-cooled, and are found in the Chevrolet Carvair, Porsches, Subaus, and Volkswagens. Subaus design is liquid cooled.

Late-model Volkswagen vans use a liquid-cooled version of the air cooled VWhorizontally opposed engine.

譯  文

新型汽車(chē)----混合動(dòng)力汽車(chē)

在油價(jià)飛漲的今天，汽車(chē)制造商被要求發(fā)展一種排放低，行駛里程長(zhǎng)的汽車(chē)。由此混合動(dòng)力車(chē)誕生了?；旌蟿?dòng)力車(chē)的特征是擁有一個(gè)小型高效的發(fā)動(dòng)機(jī)和一個(gè)輔助發(fā)動(dòng)機(jī)的電動(dòng)機(jī)。

發(fā)明這個(gè)復(fù)雜機(jī)器的原因是雙重的：減少排放，增加形式路程。第一，混合動(dòng)力車(chē)是環(huán)保的?；旌蟿?dòng)力車(chē)的排放比普通汽油機(jī)少90%。其間，混合動(dòng)力車(chē)每英里的燃料消耗少，所以排放的二氧化碳也就少。第二，混合動(dòng)力車(chē)是經(jīng)濟(jì)的?；旌蟿?dòng)力車(chē)是有發(fā)動(dòng)機(jī)和電動(dòng)機(jī)共同驅(qū)動(dòng)的，每加侖燃料可以行使大約55~60英里，而普通的SUV行使相同的距離需要至少三倍的燃料！原因有三點(diǎn)：1）混合動(dòng)力車(chē)的發(fā)動(dòng)機(jī)排量比普通汽車(chē)的都小。當(dāng)車(chē)不需要爬坡和急加速的情況下，發(fā)動(dòng)機(jī)適應(yīng)99%的駕駛情況。當(dāng)需要額外的動(dòng)力時(shí)，它可以通過(guò)發(fā)電機(jī)提供動(dòng)力。2）混合動(dòng)力車(chē)可以在怠速時(shí)使是發(fā)動(dòng)機(jī)停止工作，而僅僅依靠電動(dòng)機(jī)和電池驅(qū)動(dòng)。3)混合動(dòng)力車(chē)有能量回收裝置。電動(dòng)機(jī)可以在剎車(chē)時(shí)把能量回收，儲(chǔ)存在電池中。此外，混合動(dòng)力車(chē)要比純電動(dòng)車(chē)好，因?yàn)榛旌蟿?dòng)力車(chē)不需要給電瓶另外充電。大部分純電動(dòng)車(chē)每行使50~100英里就要充電。而且，純電動(dòng)車(chē)的速度不能大于50~60英里每小時(shí)，而混合動(dòng)力車(chē)可以。

混合動(dòng)力車(chē)以它的低油耗和長(zhǎng)行使距離填補(bǔ)了純電動(dòng)車(chē)和內(nèi)燃機(jī)車(chē)之間的空隙，同時(shí)，在油價(jià)高漲的今天混合動(dòng)力車(chē)被證明是一種可行的選擇。因此，我認(rèn)為混合動(dòng)力車(chē)擁有一個(gè)光明的未來(lái)。

油電混合汽車(chē)是如何工作的？

您或許有輛汽油車(chē)或者柴油車(chē)。您或許也聽(tīng)說(shuō)過(guò)電動(dòng)汽車(chē)。一輛混合動(dòng)力車(chē)或者是油電混合動(dòng)力車(chē)是個(gè)能量的混合體?；旌蟿?dòng)力車(chē)有兩個(gè)或兩個(gè)以上的能量來(lái)源來(lái)推動(dòng)汽車(chē)。在這種情況下，通常是由一個(gè)內(nèi)燃機(jī)和一個(gè)電動(dòng)機(jī)組成的。

那它是如何處理動(dòng)力的聯(lián)結(jié)方式呢？根據(jù)混合動(dòng)力驅(qū)動(dòng)的聯(lián)結(jié)方式通常分為三類(lèi)：并聯(lián)式，串聯(lián)式和混聯(lián)式混合動(dòng)力系統(tǒng)。

并聯(lián)式混合動(dòng)力系統(tǒng)

并聯(lián)式混合動(dòng)力系統(tǒng)式由供油系統(tǒng)，內(nèi)燃機(jī)，變速箱，電機(jī)和電池組成的。

在并聯(lián)式系統(tǒng)中，不管是內(nèi)燃機(jī)還是電機(jī)都能各自驅(qū)動(dòng)汽車(chē)，而且在某些情況下還能同時(shí)驅(qū)動(dòng)汽車(chē)。當(dāng)作為一輛普通汽車(chē)時(shí)，它的動(dòng)力來(lái)自?xún)?nèi)燃機(jī)，并通過(guò)變速箱將動(dòng)力傳到車(chē)輪。如果用電動(dòng)機(jī)驅(qū)動(dòng)，它就會(huì)利用電池的能量，并通過(guò)變速箱傳遞給車(chē)輪。

當(dāng)遇到急加速或上坡等需要額外的驅(qū)動(dòng)力時(shí)，內(nèi)燃機(jī)和電動(dòng)機(jī)會(huì)同時(shí)工作，以滿(mǎn)足需求。

當(dāng)內(nèi)燃機(jī)和并聯(lián)式混合動(dòng)力系統(tǒng)連接起來(lái)后，在使用的過(guò)程中的無(wú)用燃料消耗會(huì)大大減少，動(dòng)力得到了回收，降低了內(nèi)燃機(jī)油耗。當(dāng)在平坦的路上行駛時(shí)，大部分時(shí)間是電動(dòng)機(jī)在工作。

串聯(lián)式混合動(dòng)力系統(tǒng)

串聯(lián)式系統(tǒng)同樣擁有供油系統(tǒng)，發(fā)動(dòng)機(jī)，變速箱，電動(dòng)機(jī)和一個(gè)可以給電池充電的發(fā)電機(jī)。發(fā)電機(jī)可以是電動(dòng)機(jī)也可以是另外一個(gè)獨(dú)立的部分。

串聯(lián)式系統(tǒng)可以說(shuō)是這3種系統(tǒng)中最簡(jiǎn)單的了。發(fā)動(dòng)機(jī)并沒(méi)有和變速箱相連，而是和發(fā)電機(jī)連在一起。這意味著變速箱只能和電動(dòng)機(jī)相連，而電動(dòng)機(jī)的能量來(lái)自電池，發(fā)電機(jī)或者發(fā)動(dòng)機(jī)。

一輛串聯(lián)式混合動(dòng)力車(chē)非常適和都市交通情況，使發(fā)動(dòng)機(jī)避免了怠速和低速運(yùn)轉(zhuǎn)的工況，從而減少了油耗和排放。

混聯(lián)式混合動(dòng)力系統(tǒng)

混聯(lián)式系統(tǒng)解決了并聯(lián)和串聯(lián)式各自的問(wèn)題。由于結(jié)合了兩種系統(tǒng)的優(yōu)點(diǎn)，變速箱既可以和發(fā)動(dòng)機(jī)連接，也可以和電動(dòng)機(jī)相連，從而降低了油耗。豐田的Prius和福特的Escape Hybrid都是用的是這種 技術(shù)。

本田的混合動(dòng)力技術(shù)

我們雖然想買(mǎi)混合動(dòng)力的汽車(chē)但最終會(huì)被它的價(jià)格潑一盆冷水。事實(shí)上姑且不提飛漲的油價(jià)，另外就是我們很關(guān)心環(huán)境的，混合動(dòng)力汽車(chē)還是由于價(jià)格原因只有很小的市場(chǎng)占有率。

混合動(dòng)力被譽(yù)為下一個(gè)流行潮流，因?yàn)樗粌H減少了給氣候帶來(lái)威脅的尾氣排放，而且還解決了目前的高油價(jià)問(wèn)題。值得一提是這還是內(nèi)燃機(jī)協(xié)調(diào)燃料效能和排放方面技術(shù)進(jìn)步的表現(xiàn)。不論如何應(yīng)用，科技總是會(huì)使車(chē)的漲價(jià)。

    就是因?yàn)檫@樣，只有在一特殊的小市場(chǎng)里的少部分的人們可以買(mǎi)的起這樣的車(chē)，他們?cè)诿酥杏幸环N形象特殊的地位。對(duì)于大多數(shù)的人來(lái)說(shuō)，他們不并不是一個(gè)選擇。那種情況很快就會(huì)改變的。

全球最大的汽車(chē)生產(chǎn)商和燃料效能技術(shù)機(jī)構(gòu)本田機(jī)車(chē)公司將要在2009年推出一款低價(jià)位的混合動(dòng)力汽車(chē)。如果可以的話(huà)他們希望使這款車(chē)成為大眾能接受的主流車(chē)型，達(dá)到更大的銷(xiāo)售量并具有更廣泛的吸引力的目標(biāo)。

當(dāng)然這樣做會(huì)使底特律緊張起來(lái)，并給美國(guó)的汽車(chē)生產(chǎn)商們發(fā)出了一個(gè)信號(hào)：你們應(yīng)該著手生產(chǎn)他們?cè)瓉?lái)忽視的東西，那些更環(huán)保和燃油經(jīng)濟(jì)性更好的汽車(chē)了，在過(guò)去由于混合動(dòng)力很少的市場(chǎng)占有率和高油耗svu車(chē)型有更大的利潤(rùn)使他們并不重視混合動(dòng)力的研發(fā)。

 現(xiàn)在本田不僅正在和全球最大的汽車(chē)制造商而且還是制造普銳斯---混合動(dòng)力汽車(chē)的代名詞的豐田公司來(lái)較量了。本田挑戰(zhàn)一個(gè)看上去不可戰(zhàn)勝被豐田掌控的市場(chǎng)。

 同時(shí)豐田正致力于降低普銳斯的制造成本，從而降低其市場(chǎng)價(jià)格。所有的注意都集中在2009年的潛在的汽車(chē)消費(fèi)市場(chǎng)。

 于此同時(shí)，態(tài)度強(qiáng)硬的全球變暖的反對(duì)者更堅(jiān)信生態(tài)災(zāi)難就要來(lái)臨，或許已經(jīng)是到結(jié)束我們對(duì)suv車(chē)型的鐘愛(ài)，并著手降低成品油消費(fèi)的時(shí)候了。

 油價(jià)漲到了4美元并且還在無(wú)限制的增長(zhǎng)，我們可能只有很小的選擇空間了。

發(fā)動(dòng)機(jī)工作原理

大多數(shù)汽車(chē)的發(fā)動(dòng)機(jī)是內(nèi)燃機(jī)，往復(fù)四沖程汽油機(jī)，但是也有使用其它類(lèi)型的發(fā)動(dòng)機(jī)，包括柴油機(jī)，轉(zhuǎn)子發(fā)動(dòng)機(jī)，二沖程發(fā)動(dòng)機(jī)和分程燃燒發(fā)動(dòng)機(jī)。

往復(fù)的意思就是上下運(yùn)動(dòng)或前后運(yùn)動(dòng)，在往復(fù)發(fā)動(dòng)機(jī)中，氣缸中活塞的上下運(yùn)動(dòng)產(chǎn)生發(fā)動(dòng)機(jī)的動(dòng)力，這種類(lèi)型幾乎所有的發(fā)動(dòng)機(jī)都是依賴(lài)氣缸體即發(fā)動(dòng)機(jī)缸體，缸體是鑄鐵或鑄鋁制的，它包括發(fā)動(dòng)機(jī)氣缸和冷卻液循環(huán)用的水套。缸體的頂部是氣缸蓋，它組成了燃燒室，缸體底部是油底殼。

氣缸內(nèi)活塞的直線(xiàn)運(yùn)動(dòng)產(chǎn)生動(dòng)力，然而，必須將直線(xiàn)運(yùn)動(dòng)轉(zhuǎn)化成旋轉(zhuǎn)運(yùn)動(dòng)，使汽車(chē)車(chē)輪轉(zhuǎn)動(dòng)，活塞銷(xiāo)將活塞連接在連桿頂部，連桿底部與曲軸連接，使汽車(chē)車(chē)輪轉(zhuǎn)動(dòng)，活塞銷(xiāo)將活塞連桿頂部，連桿底剖與曲軸連接，連桿將活塞的往復(fù)運(yùn)動(dòng)傳遞給曲軸，曲軸將其轉(zhuǎn)化為旋轉(zhuǎn)運(yùn)動(dòng)，連桿是用連桿曲軸安裝在曲軸上的，用類(lèi)似的軸承即主軸承將曲軸固定在缸體內(nèi)。

氣缸的直徑稱(chēng)為發(fā)動(dòng)機(jī)的內(nèi)徑，排量和壓縮比是兩個(gè)常用的發(fā)動(dòng)機(jī)參數(shù) ，排量是指發(fā)動(dòng)機(jī)的大小，壓縮比是氣缸總?cè)莘e與燃燒室壓縮容積之比。

術(shù)語(yǔ): 沖程是用來(lái)說(shuō)明活塞在氣缸內(nèi)的運(yùn)動(dòng)，也就是活塞行程的距離根據(jù)發(fā)動(dòng)機(jī)類(lèi)型的需要二沖程或四沖程來(lái)完成一個(gè)工作循環(huán)四沖程發(fā)動(dòng)機(jī)也叫做奧托發(fā)動(dòng)機(jī)，為了紀(jì)念德國(guó)工程 師奧托，他是在1876年第一個(gè)應(yīng)用該原理的，在四沖程發(fā)動(dòng)機(jī)中，要求氣缸活塞四沖程來(lái)完成一個(gè)完整的工作循環(huán)，每個(gè)沖程根據(jù)其行為命名分別為: 進(jìn)氣沖程，壓縮沖程，作功沖程和排氣沖程。

1、進(jìn)氣沖程

當(dāng)活塞下移時(shí)，霧化后的可燃混合氣通過(guò)打開(kāi)的進(jìn)氣門(mén) 進(jìn)入氣缸，為了達(dá)到最大的進(jìn)氣量，進(jìn)氣門(mén)在活塞到達(dá)上止點(diǎn)前10°打開(kāi)，使進(jìn)、排氣門(mén)有20°打開(kāi)重疊角，進(jìn)氣門(mén)一直打開(kāi)到活塞到達(dá)下止點(diǎn)充分進(jìn)入混合氣之后50°左右。

2、壓縮沖程

活塞開(kāi)始向上移動(dòng)時(shí)，進(jìn)氣門(mén)關(guān)閉，混合氣在燃燒室中壓縮，根據(jù)不同因素包括壓縮比，節(jié)氣門(mén)開(kāi)度，發(fā)動(dòng)機(jī)轉(zhuǎn)速壓力上升到約1兆帕，接近沖程頂部時(shí)，火花塞產(chǎn)生的電火花擊穿點(diǎn)火間隙點(diǎn)燃可燃混合氣。

3、作功沖程

燃燒膨脹的氣體產(chǎn)生的壓力上升到3.5個(gè)兆帕?xí)r，推動(dòng)活塞下移，接近氣缸底時(shí)，排氣門(mén)打開(kāi)。

4、排氣沖程

隨著排氣門(mén)開(kāi)啟約下止點(diǎn)前50°，活塞回升，使氣缸內(nèi)壓力下降在排氣沖程，減少對(duì)活塞回壓，派出廢氣，為下一個(gè)進(jìn)氣沖程作準(zhǔn)備，通常情況下，進(jìn)氣門(mén)在排氣沖程完成前打開(kāi)。

只要發(fā)動(dòng)機(jī)保持運(yùn)轉(zhuǎn)，每個(gè)氣缸內(nèi)四個(gè)沖程循環(huán)連續(xù)不斷地重復(fù)下去。

兩沖程發(fā)動(dòng)機(jī)也同樣通過(guò)四行程來(lái)完成，一個(gè)工作循環(huán)但是進(jìn)氣沖程，壓縮沖程合為一個(gè)沖程，作功沖程形成另一個(gè)沖程，術(shù)語(yǔ)兩行程循環(huán)和兩行程就是所謂的術(shù)語(yǔ)雙循環(huán)但實(shí)際上并不太準(zhǔn)確。

在所用的汽車(chē)發(fā)動(dòng)機(jī)中，所有的活塞都是固定在一個(gè)曲軸上的，氣缸中發(fā)動(dòng)機(jī)越多，每轉(zhuǎn)為發(fā)動(dòng)機(jī)的作功沖程產(chǎn)生越多的動(dòng)力，這就意味著八缸發(fā)動(dòng)機(jī)運(yùn)轉(zhuǎn)的越平順，因?yàn)榘l(fā)動(dòng)機(jī)在作功沖程中運(yùn)轉(zhuǎn)時(shí)間和旋轉(zhuǎn)角度緊密。

多氣缸發(fā)動(dòng)機(jī)有三種排列形式，任其一種

1、直列式發(fā)動(dòng)機(jī)用一個(gè)氣缸體，大多數(shù)四缸發(fā)動(dòng)機(jī)和一些六缸發(fā)動(dòng)機(jī)都采用這種型式，這種氣缸不必垂直分布，它們可以向任一方向傾斜。

2、V-型發(fā)動(dòng)機(jī)用兩排同樣的氣缸，通常夾角為60°或90°，大多數(shù)有六缸或八缸，盡管四缸和十二缸也有采用V型的。

3、 臥式或者對(duì)置式發(fā)動(dòng)機(jī)有兩排互為180°的氣缸，這些節(jié)省窨發(fā)動(dòng)機(jī) 設(shè)計(jì) 通常采用風(fēng)冷式，在雪弗蘭、富士、大眾車(chē)采用這種型式，富士汽車(chē)采用水冷式，在頂置式風(fēng)冷發(fā)動(dòng)機(jī)中，大眾的新型廂式汽車(chē)采用水冷式。

在未來(lái)的20年，內(nèi)燃機(jī)仍是各種通用機(jī)械的主要?jiǎng)恿ΓS著汽油和柴油的質(zhì)量越來(lái)越高以及內(nèi)燃機(jī)技術(shù)的快速發(fā)展，能量利用效率得到了明顯的提高，同時(shí)代用燃料也會(huì)得到迅速運(yùn)用，小型的廢氣渦輪增壓內(nèi)燃機(jī)的研制，必將對(duì)我國(guó)內(nèi)燃機(jī)行業(yè)的發(fā)展及節(jié)約能源方面起到重要的作用。因此，如何結(jié)合我國(guó)國(guó)情來(lái)發(fā)展內(nèi)燃機(jī)行業(yè)及中國(guó)的燃料，開(kāi)發(fā)研究新的節(jié)能技術(shù)，制定科學(xué)的、符合發(fā)展的戰(zhàn)略，是我國(guó)內(nèi)燃機(jī)行業(yè)科研單位乃至國(guó)家政府必須重視的問(wèn)題。

1．研究提高內(nèi)燃機(jī)制造的關(guān)鍵技術(shù)

近幾年我國(guó)通過(guò)技術(shù)引進(jìn)和技術(shù)改造，內(nèi)燃機(jī)技術(shù)已經(jīng)有了長(zhǎng)足的進(jìn)步，走上了健康的發(fā)展之路。但在關(guān)鍵技術(shù)還遠(yuǎn)遠(yuǎn)落后于國(guó)外先進(jìn)水平，所以，在關(guān)鍵技術(shù)上要加大科技投入，重點(diǎn)扶持油泵油嘴、增壓器等關(guān)鍵零部件產(chǎn)業(yè)；充分利用電子控制、共軌系統(tǒng)等高新技術(shù)來(lái)改進(jìn)內(nèi)燃機(jī)及燃燒系統(tǒng)；解決整機(jī)開(kāi)發(fā)及匹配技術(shù)，如柴油機(jī)燃油、進(jìn)氣及燃燒系統(tǒng)的匹配與優(yōu)化技術(shù)；有計(jì)劃的改進(jìn)內(nèi)燃機(jī)的制造工藝及材質(zhì)的問(wèn)題，提高內(nèi)燃機(jī)的質(zhì)量，增加能源利用效率，以達(dá)到節(jié)約能源的目的。

研究開(kāi)發(fā)高速直噴燃燒系統(tǒng)。我國(guó)小型高速柴油機(jī)普遍采用渦流室，比直噴機(jī)型油耗高10％～15％。我國(guó)小型高速直噴柴油機(jī)處于研究開(kāi)發(fā)階段。

2．研究開(kāi)發(fā)綜合燃燒系統(tǒng)的內(nèi)燃機(jī)

回顧內(nèi)燃機(jī)發(fā)展歷程，汽油機(jī)及柴油機(jī)都有各自的優(yōu)點(diǎn)，而且已經(jīng)表明汽油機(jī)與柴油機(jī)在互相滲透，揚(yáng)長(zhǎng)避短，為了適應(yīng)燃料多元化及節(jié)約能源的要求，必須將汽油機(jī)及柴油機(jī)工作過(guò)程的優(yōu)點(diǎn)綜合在一起，研究開(kāi)發(fā)新的綜合燃燒系統(tǒng)。增加柴油機(jī)的均質(zhì)預(yù)混合部分，取消汽油機(jī)的點(diǎn)火系統(tǒng)，增加壓縮比；運(yùn)用成熟的納米材料及納米技術(shù)。

3．研究及開(kāi)發(fā)代用燃料

我國(guó)每年都需要進(jìn)口大量的石油，而且逐年在增長(zhǎng)，石油資源逐漸枯竭，所以必須考慮替代燃料，目前已經(jīng)應(yīng)用和發(fā)展了多元化的燃料，包括天然氣(CNG)、液化石油氣(LPc)、甲醇、乙醇、氫、二甲醚及生物柴油等，其中天然氣、液化石油氣、乙醇已經(jīng)得到了應(yīng)用，氫氣是理想的清潔燃料，是科研人員追求的目標(biāo)。目前，無(wú)論用水或生物質(zhì)制氫，都是效率低、成本高，包括儲(chǔ)存的一些技術(shù)仍遠(yuǎn)未解決。納米材料及納米技術(shù)有助于解決這一問(wèn)題，但這需要較長(zhǎng)時(shí)間的開(kāi)發(fā)研究，寶馬公司一直致力于氫氣內(nèi)燃機(jī)的研制，開(kāi)發(fā)了多款氫內(nèi)燃機(jī)汽車(chē)，其中V12氫內(nèi)燃機(jī)是世界上首批用于轎車(chē)上的內(nèi)燃機(jī)，該內(nèi)燃機(jī)可使用氫氣和汽油兩種燃料；從20世紀(jì)80年代起國(guó)外就開(kāi)始研究生物質(zhì)能，不斷取得一些成果，但仍未達(dá)到商業(yè)化的水平，據(jù)專(zhuān)家預(yù)測(cè)，2010年左右可達(dá)到廉價(jià)工業(yè)化要求。我國(guó)有關(guān)大學(xué)及科研單位也在進(jìn)行研究、開(kāi)發(fā)和應(yīng)用生物質(zhì)能及燃料，這是經(jīng)濟(jì)可持續(xù)發(fā)展的必由之路。

4．增壓技術(shù)應(yīng)該向中小功率內(nèi)燃機(jī)發(fā)展

內(nèi)燃機(jī)增壓技術(shù)在上世紀(jì)60年代才獲得了迅速的發(fā)展和廣泛的推廣使用，采用增壓技術(shù)的內(nèi)燃機(jī)可以降低油耗2％～5％，但目前大中型內(nèi)燃機(jī)使用較多，而中小型的內(nèi)燃機(jī)應(yīng)用比較少。所以增壓技術(shù)應(yīng)向中小功率內(nèi)燃機(jī)擴(kuò)展，隨著小型渦輪增壓器結(jié)構(gòu)的可靠性不斷提高，我國(guó)應(yīng)盡快開(kāi)發(fā)小型廢氣渦輪增壓汽油機(jī)及柴油機(jī)。

5．內(nèi)燃機(jī)的柴油機(jī)化

內(nèi)燃機(jī)作為最廣泛的動(dòng)力機(jī)械，其中我國(guó)汽油機(jī)占40％，其余為柴油機(jī)。柴油機(jī)的熱效率比汽油機(jī)高，通常可以節(jié)油25％以上，這是世界上早已達(dá)成的共識(shí)。隨著設(shè)計(jì)、制造技術(shù)、材料技術(shù)水平的提高，柴油機(jī)取代汽油機(jī)的技術(shù)障礙將逐步被克服，特別是近年“石油危機(jī)”以來(lái)，世界各國(guó)“柴油機(jī)化”迅速發(fā)展，不但農(nóng)用發(fā)動(dòng)機(jī)采用柴油機(jī)，各類(lèi)機(jī)動(dòng)車(chē)用發(fā)動(dòng)機(jī)也采用柴油機(jī)，就是有些轎車(chē)也采用柴油機(jī)。