汽车使用英语课.ppt

Unit 4 Internal Combustion Engine Construction Notes to Text 1、The piston, through the connecting rod, transfers to the crankshaft the force created by the burning fuel mixture. This force turns the crankshaft. Thin, circular, steel bands fit into grooves around the piston to seal the bottom of the combustion chamber. These bands are called piston rings. The grooves into which they fit are called ring grooves. 活塞通过连杆与曲轴相连，并将燃烧混合气产生的力传给曲轴。这种力使曲轴转动。把薄钢圈放进活塞周围的凹槽以密封燃烧室的底部。这些圈叫做活塞环。安装活塞环的凹槽称为活塞环槽。 2、A piston pin fits into a round hole in the piston. The piston pin joins the piston to the connecting rod. The thick part of the piston that holds the piston pin is the pin boss. 活塞销装在活塞的环形的孔里。活塞销把活塞和连杆连接起来。用来支撑活塞销的活塞厚的部分称为活塞销凸台。 3、A bush made from a soft metal, such as bronze, is used for this joint. The lower end of the connecting rod fits the crankshaft journal. This is called the big end. For this big-end bearing, steel-backed lead or tin shell bearings are used. These are the same as those used for the main bearings. The split of the big end is sometimes at an angle, so that it is small enough to be withdrawn through the cylinder bore. The connecting rod is made from forged alloy steel. 衬套由软金属制成，例如青铜，被用于这种连接。在连杆低端安装曲柄轴颈。这被称为连杆大头。对连杆大头轴承来说，使用的是钢背铅轴承或轴瓦式锡轴承。这些轴承与那些被用作主要轴承的轴承相同。大头的裂口有时有一个角度，以便足够小通过气缸。连杆由锻造的合金钢制成。 4、The crankshaft, in conjunction with the connecting rod, converts the reciprocating motion of the piston to the rotary motion needed to drive the vehicle. It is usually made from carbon steel which is alloyed with a small proportion of nickel. The main bearing journals fit into the cylinder block and the big end journals align with the connecting rods. At the rear end of the crankshaft is attached the flywheel, and at the front end are the driving wheels for the timing gears, fan, cooling water and alternator. 曲轴和连杆一起，把活塞的往复运动转化为驱动车辆需要的旋转运动。通常由含少量镍的碳钢制成。主要轴承轴颈安装在气缸体和匹配连杆大头末端的轴颈上。曲轴的后端连接着飞轮，前端是连接着定时齿轮、风扇、冷却水和交流发电机的驱动轮。 5、The throw of the crankshaf