【正文】 一個多缸發(fā)動機有三種布置形式。 開啟，并有 20176。然而，這個直線運動必須要變?yōu)檐囕喌仔D運功。這將破壞發(fā)動機。這個銷子用來連接連桿小頭的。然后給它們涂上一層化學制劑，把表面上的鋁腐蝕掉。它包括汽缸體本身和環(huán) 繞在周圍的水套。 往復式發(fā)動機 在這種類型汽車的發(fā)動機里，活塞在各自的汽缸里往復運動。after b. d . c. to take advantage of ining mixture. （ 2） Compression stroke The piston turns up, the intake valve closes, the mixture is pressed within the bustion chamber, while the pressure rise to about 1Mpa depending on various factors including the pression 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 bustion produces a rise in pressure of the gas to some Mpa, and the piston is forced down in the cylinder. The exhaust valve opens near the bottom of the stroke. （ 4） Exhaust stroke The piston moves back up with the exhaust valve open some 50176。 發(fā)動機上的許多東西都是有要求，它們常用于推動發(fā)動機，許多的要求如下： （ 1）容易起動性能： (2)可靠性。四缸汽車發(fā)動機的基本部件包括： （ 1）汽缸體。最根本的不同是柴油機的比汽油機的更加堅固更沉?；钊敳坑蟹胖没钊h(huán)的活塞環(huán)槽。裝軸瓦時必須使軸瓦上的小孔與連桿上的對準。 天津職業(yè)技術師范大學 2021屆本科生畢業(yè)設計 曲軸非常堅硬，它是一塊合金 經(jīng)過鍛造、熱加工而成的。和軸承類似，也叫主軸承備用來將曲軸裝在機體上。在活塞接近上止點時，混合氣被擊穿火花塞間隙的火花點燃。 （ 3）兩列氣缸彼此相差 180 度成臥式。 一個兩沖程的發(fā)動機也是通過四個動作來完成一個工作循環(huán)的。四沖程發(fā)動機也叫奧托發(fā)動機，是為了紀念德國工程師，奧托先生，他在 1876 年第一次提出了這個理論。大多數(shù)發(fā)動機是依靠汽缸體或者說發(fā)動機體。發(fā)動機在運轉時可能發(fā)生曲軸抱死。踏板連著自行車 的軸，這個軸類似于曲軸因為它也用來驅(qū)動車輪。因此，鋁制氣缸要有氣缸襯套，因此在鋁中加入 硅粒子形成鋁合金。 （ 7）汽缸蓋。 有些性能是互相沖突的，例如，很大的動力需要以尺寸是足夠大的發(fā)動機上獲得，但是這么大的尺寸的發(fā)動機工作時經(jīng)濟性不好，因此，所有汽車的發(fā)動機都是為獲的滿意的性能和經(jīng)濟性。天津職業(yè)技術師范大學 2021屆本科生畢業(yè)設計 Engine Fundamentals Automobiles have been operated successfully by electric motors ,steam engines ,and internal bustion engines .The internal bustion engine burns fuel within its cylinders and converts the expanding force of the burning fuel ,or bustion, into a rotary force used to propel the vehicle. There are several types of internal bustion engines: twoand fourcycle reciprocating piston engines ,gas turbine engines .However ,fourcycle reciprocating engines have been refined to such a degree that they have almost plete dominance of the automotive field .Engines of other types are described in Chapter 18 ,Diesel and Other Engines. Many things are demanded of an engine used to propel an automobile. Some of the requirements are: （ 1） Ease of starting. （ 2） Reliability. （ 3） Power. （ 4） Responsiveness. （ 5） Economy in fuel ,oil ,and ,repairs. （ 6） Ease of handling. （ 7） Quiet operation. Some of these factors conflict .For example ,a great amount of power can be had from an engine of sufficient size, but a supersize engines is not economical to operate .Therefore ,all automobile engines are a promise in order to obtain the desirable bination of performance and economy. Engine fuels Internal bustion engines can be made to operate on almost anythi ng that can be converted into a bustible gas, such as wood ,coal, alcohol, vegetable oils, mineral oils, etc. However, because of convenience, a variety of petroleum products are monly used as fuel :gasoline, kerosene ,fuel oil ,liquefied petroleum gas (LPGas) ect. What kerosene ,fuel oil ,or LPGas is used it is necessary to alter the design of the engine to achieve efficient operation. 天津職業(yè)技術師范大學 2021屆本科生畢業(yè)設計 Engine Deign Gasoline engines used in automotive vehicles are of two basic types :fourcycle engines and twocycle engines .Either type may be watercooled ,or aircooled .Four ,six, and eightcylinder engines are mon However, three, five, ten ,and twelvecylinder engine are available. Almost all automobile engines have more than one cylinder. These cylinders can be arranged in an inline ,opposed ,or Vtype configuration. Engines for other purpose ,such as aviation, are arranged as radial, inverted inline ,inverted V, and Xshaped