中英文文獻翻譯-發(fā)動機工作原理概述

1、 附錄 A 外文文獻Engine operating principlsMost automobile dngines are internal combustion, reciprocating4-stroke gasolineengines, but other types have been used, including the diesel, the rotary (wankel),the2-stroke ,and stratifild charge.Recipprocating means up and down or banck and forth, it is the up a

2、n down action of apiston in the cylinder blick ,or engine block . the blick is an iron or aluminum casting thatcontains engine cylinders and passage called water jackets for coolant circulation .the top ofthe block is covered with the cylinder head. Which forms the combustion chanber. Thebottom of t

3、he 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 linearmotion must be changed into rotary motion to turn the wheels of cars of trucks. The pistionis attached to the top of a connecting rod by a pin, called a pistion pin or

4、 wrist pin thebottom of the connecting rod is attached to the crankshaft . the connecting rod transmits theup-and-down motion of the piston to the crankshaft , which changes it into rotarymotion.The connecting rod is mounted on the crankshaft with large beaings called rod bearings.Similar bearings,

5、called main bearings, are used to mount the crankshaft in the block .shownin fig ,1-1.The diameter of the cylinder is called the engine bore. Displacement and compressionratio are two frequently used engine specifications. Displacement indicates engine size , andcompression ratio compares the total

6、cylinder volume to compression chamber volume.The term stroke is uesd to describe the movement of the iston within the cylinder, aswell as the distance of pistion travel. Depending on the type of engine the operating cyclemay require either two or four strokes to complete. The 4-strokes engine is al

7、so called ottocycle engine ,in honor of the german enginner , Dr. Nikolaus otto , who first applied theprinciple in 1876 . In the 4-stroke engine ,four strokes of the piston in the cylinder arerequired to complete one full operating cycle .Each stroke is named after the action itperformes instake ,

8、compression ,power, and exhaust in that order, shown in Fig1-2.1、Instake strokeAs the piston moves down , the vaporized mixture of fuel and air enters the cylinder through open instake vavle. To obtain the maximum filling of the cylinder the instake valveopens about 10 before t.b.c ,giving 20 overla

9、p. The inlet valve remains open until some50 after b.d.c to take advantage of incoming mixture.2、Compression strokeThe pieton turns up , the instake valve closes, the mixture is compressed within thecombustion chamber, while the pressure rise to ahout 1 Mpa, depending on various factorsinclouding th

10、e compression ratio, throttle opening and engine speed. Near the top of thestroke the mixture is ignited by a spark which bridge the gap of the spark plug.3、Power strokeThe expanding gases of combution produces a rise in pressure of the gas to some3.5Mpa, and the piston is forced down in the cylinde

11、r. The exhaust valve opens near thebottom of the stroke.4、Exhust strokeThe piston moves back up with the exhause valve open some 50beforeb.d.d.,allowing the pressure within the cylinder to fall and to reduce back pressure onthe piston during the exhaust stroke, and the burned gases are pushed out to

12、 prepare for thenext instake stroke. The instake valve usually opens just before the exhaust stroke.This 4-stroke cycle is continuously repared in every as long as the engineremainsrunningA-2-stroke engine also goes through four actions to complete one operating cycle.However , the instake and the c

13、ompression actions are combined in one seroke,and thepower and exhaust actions are combined in the other stroke. The term2-stroke cycle or2-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.

14、The morecylinders an engine has ,the more power strokes produced for cach revolusion. This meansthat means that an 8-cylinder engine runs more smoothly because the power atrokes arecloser together in time and in degrees of engine rotation.The cylinder of multi-cyclinder automotive engines arranged i

15、n one of three ways.1、Inline engine use a single block of cylinder. Most 4-cylinder and 6-cylinder engines areof this design. The cylinder do not have to be vertical. They can be inclined either side.2、V-type engine use two equal bands of cylinder , usually inclined 60degrees or 90degreesfrom the ca

16、ch other. Most V-type engines have 6 or 8 cylinders, although V-4 and V-12 engine have been built.3、Horizontally opposed or pancake engine have two equal banks of cylinders 180degreesapart . these space saving engine designs are often air-cooled,and are found in thechevrolet carvair porsches, Subaus

17、,and Volkswagens. Subaus design is liquidcooled.Later model Volkswagen vans use a liquil-cooled VWhorizontally opposedengine. 附錄 B 中文翻譯發(fā)動機工作原理大多數(shù)汽車的發(fā)動機是內燃機，往復四沖程汽油機，但是也有使用其他類型的發(fā)動機，包括柴油機，轉子發(fā)動機二沖程發(fā)動機和分程燃燒發(fā)動機。往復的意思就是上下或前后運動，在往復發(fā)動機中，氣缸中活塞的上下運動產生發(fā)動機的動力，這種類型幾乎所有的發(fā)動機都是依賴氣缸體即發(fā)動機缸體，缸體是鑄鐵或鑄鋁制的，它包括發(fā)動機氣缸和冷卻液循環(huán)用

18、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。氣缸內活塞的運動產生動力，然而，必須將直線運動轉化為旋轉運動，使汽車車輪轉動，活塞銷將活塞連接在連桿頂部，連桿底部與曲軸連接，使汽車車輪轉動，活塞銷將活塞連桿頂部、連桿底部與曲軸連接，連桿將活塞的往復運動傳遞給曲軸，曲軸將其轉化為旋轉動力，連桿是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。氣缸的直徑成為發(fā)動機的內徑，排量和壓縮比是兩個常用的發(fā)動機參數(shù)，排量是指發(fā)動機的大小，壓縮比是氣缸總容積與燃燒室壓縮容積之比。術語：沖程是用來說明活塞在氣缸內的運動，也就是活塞行程的距離根據(jù)發(fā)動機類型的需要二沖程或四沖程來完成一個完整的工作循環(huán)，每個在沖程根據(jù)其行為命名分別為：進氣沖程、壓縮沖程、作功行沖程和排氣行沖程。1、進氣沖程當活塞下移時，霧化后的可燃混合氣通過打開的進氣門進入氣缸，為了達到最大的進氣量，進氣門在活塞到達上止點前 10打開，使進、排氣有20打開重疊角，進氣門一直打開到活塞到達下止點充分進入混合氣之后 50左右。2、壓縮沖程活塞開始向上移動時，進氣門關閉，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