外文翻譯--發(fā)動(dòng)機(jī)工作原理

附錄 1 Engine Operating Principles Most automobile engines 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 dowm or banck and forth ,It is the up and down action of a piston in the cylinder blick,or engine block.The bilck is an iron or aluminum casting that contains engine cylinders and passges called water jackets for coolant circulation.The top of the block is convered with the cylinder head.Which forms the combustion chanber.The bottom of the block is covered with an oil pan or oil sump. Power ia 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. Term: stroke is used to indicate the movement within the cylinder piston, piston stroke is the distance from the engine type according to need two-stroke or four-stroke cycle to finish a job and four stroke engines are also called otto engine, in order to commemorate German engineers otto, he is the first application in 1876, the principle of in four stroke engines, cylinder piston required to complete a four-stroke cycle, each stroke work according to their behavior named respectively: intake stroke, compression stroke, function and exhaust stroke. 1. Intake stroke When the piston moves down, spray the mixture through open after entering the inlet valve, in order to achieve maximum cylinder amount of inlet in Detroit, arrive before BDC 10 , open and exhaust has 20 to open the inlet valve overlap, has been opened to the pistons to come fully into the mixture after about 50 . 2. Compression stroke The piston start moving up huge inlet valve closed, and the mixture in the combustion chamber, according to the different factors including compression compression ratio, the throttle valve, pressure revs up to about 1 mpa, close to the top, the spark plug stroke produces the spark gap in the breakdown ignition mixture lighting. 3. Doing work Burning gas pressure of inflation rose to 3.5 mpa, promote the piston moves to the cylinder, and exhaust door open. 4 gas stroke With exhaust before more open about 50 , piston, make up in the air pressure drops in exhaust stroke, reduce backpressure, discharge waste piston stroke, for the next intake, normally, inlet in exhaust before opening. Only the engine keep running, each cylinder within four four-stroke cycle continuously.Two stroke engine also through the four-stroke cycle to complete a job but intake stroke, compression stroke for a stroke, do work schedule another stroke, the four-stroke cycle and two terms two travel itinerary is called the term two-cycle but actually not so accurate. 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 term 2-stroke cyde or 2-stroke is preferred to the term 2-cyde,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 bacause the power atrokes are closer togther 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 60 degrees or 90 degrees 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 180 degrees 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.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. 發(fā)動(dòng)機(jī)工作原理 大多數(shù)汽車的發(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 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)和分成燃燒發(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，汽缸中活塞的上下運(yùn)動(dòng)產(chǎn)生發(fā)動(dòng)機(jī)的動(dòng)力，這種那個(gè)類型幾乎所有的發(fā)動(dòng)機(jī)都是依賴汽缸體即發(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。缸體的頂部是汽缸蓋，它組成了燃燒室，缸體地步是油底殼。 氣缸內(nèi)活塞的直線運(yùn)動(dòng)產(chǎn)生動(dòng)力，然而，必須將直線運(yùn)動(dòng)轉(zhuǎn)化成旋轉(zhuǎn)運(yùn)動(dòng)，使汽車車輪轉(zhuǎn)動(dòng)，活塞銷將活塞連接在連桿頂部，連桿底部與曲軸連接，使汽車車輪轉(zhuǎn)動(dòng)，活塞銷將活塞連桿頂部，連桿底部與曲軸連接 ，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)，連桿式用連桿曲軸安裝在曲軸上的，用類似的軸承即主軸承將曲軸固定在缸體內(nèi)。 氣缸的直徑稱為發(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，壓縮比試氣缸總?cè)莘e與燃燒室壓縮容積之比。 術(shù)語：沖程是用來說明活塞在氣缸內(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)類型的需要二沖程或四沖程來完成一個(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完成一個(gè)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打開的進(jìn)氣門進(jìn)入氣缸，為了達(dá)到最大的進(jìn)氣量，進(jìn)氣門在活塞到達(dá)上止點(diǎn)前 10打開，使進(jìn)、排氣門有 20打開重疊角，進(jìn)氣門一直打開到活塞到達(dá)下止點(diǎn)充分進(jìn)入混合氣之后 50左右。 2.壓縮沖程 活塞開始向上移動(dòng)是時(shí)，進(jìn)氣門關(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)氣門開度，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)生的電火花在擊穿點(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，接近汽缸底時(shí)，排氣門打開。 4.燃?xì)鉀_程 隨著排氣門開啟約不止點(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，排出廢氣，為下一個(gè)進(jìn)氣沖程作準(zhǔn)備，通常情況下，進(jìn)氣門在排氣沖程完成前打開。 只有發(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)也同樣通過四行程來完成，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，作功沖程行程另一個(gè)沖程，術(shù)語兩行程循環(huán)和兩行程就是所謂的術(shù)語雙循環(huán)但實(shí)際上并不太準(zhǔn)確。 在所用 的汽車發(fā)動(dòng)機(jī)中，所有的活塞都是固定在一個(gè)曲軸上的，汽缸中發(fā)動(dòng)機(jī)越多，每轉(zhuǎn)