汽车起重机吊臂伸缩机构的常见故障:一是伸缩臂伸缩时有时会出现抖动并发出异响;二是伸缩臂有时不能回缩或伸缩臂自动下沉。1.故障原因分析(1)平衡阀阻尼孔堵塞或平衡阀内弹簧变形。(2)伸缩缸运行时活塞与缸筒、活塞杆与导向套之间会发出响声,且常伴有爬行和振动现象。 Truck cranes crane retractable mechanism common faults: First, telescopic telescopic sometimes jitter and audible noise; second telescopic arm sometimes can not retract or telescopic arm automatically sink. 1. Analysis of the cause of the malfunction (1) Balance valve damping orifice blocked or balanced valve spring deformation. (2) When the telescopic cylinder is running, the piston and the cylinder tube will emit a sound between the piston rod and the guide sleeve, often accompanied by the phenomenon of creeping and vibration.