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一、敲击声机器运转时,动配合零件会因为间隙改变方向发生撞击而出现声响,这些声响会随着间隙增大而增强.当小零件相撞时,声音清脆;大零件相撞时,声音沉重;大小零件相撞时,似手锤敲击铁钻;硬、软零件相撞(如轴与瓦),声音闷哑.这些音调,音色的不同特点,为判断哪个零件出故障提供了依据.(一)逐渐出现的敲击声随着机器日渐用旧,有些敲击声常在不知不觉中出现,开始比较轻微,以后日渐严重,伴随机器震动增大.这是运动零件磨损、配合间隙增大的表现.1.发动机怠速空载运转时,在气缸内连续不断发出轻微的“的哒、的哒”金属敲击声.原因:①气门间隙过大,摇臂撞气门杆;②气门杆与气门导管的配合间隙过大;③气门推杆与气门导管的间隙过大;④配合凸轮轴磨损后,气门挺柱在凸轮上有跳动.2.活塞销响声.发动机在低速向中速急加油时即能听到明显的“嗒嗒”声.特点:每抖动一次油门,响声随之增大,且声音清脆连贵;发动机温度升高后,响声不减弱;“断火”检查,响声消失或减弱.当恢复该缸工作的瞬间声音大而清脆.原因:①活塞销与连杆小头衬套松旷;②活塞销与活塞上的销孔配合松旷.
First, the percussion sound When the machine is running, moving parts with the impact of changes in the direction of the gap and the emergence of sound, these sounds will increase as the gap increases .When small parts collide, the sound crisp; large parts collide, The sound is heavy; when the size of the parts collided, like hand hammer hit the drill; hard and soft parts collide (such as shaft and tile), dull sound.These different characteristics of tone, timbre, to determine which part provides a fault According to (a) the gradual emergence of the percussion With the growing use of the machine, some percussion often unknowingly appear, began relatively minor, then increasingly serious, accompanied by increased machine vibration.This is the wear and tear of moving parts, With the performance of increased clearance .1 engine idle no-load operation, in the cylinder continuously issued a slight “da, da” metal percussion reasons: ① valve clearance is too large, rocker hit the valve stem; ② valve stem and valve guide with the gap is too large; ③ valve push rod and valve guide gap is too large; ④ with the camshaft wear, the valve tappet beating on the cam .2. Piston pin sound. Engine at low speed When you are in a hurry, you can hear the obvious “click.” “Sound. Features: Each jerk once the throttle, the sound increases, and the sound crisp and expensive; engine temperature increases, the sound does not diminish;” off fire "check, the sound disappears or weakened. When the moment to resume the cylinder work Loud and crisp sound. Reason: ① piston pin and connecting rod small head bushing loose Kuang; ② piston pin and pin hole on the piston with loose Kuang.