一辆上海桑塔纳 LX 型轿车,在行驶中连杆竟钻出缸体之外。经检查是连杆螺栓的问题。造成该事故的可能原因有二:一是修理工在修理 JV 型发动机时,没有按规定要求更换连杆螺栓和螺母,或是没有按规定的力矩拧紧连杆螺母;二是驾驶员粗心大意,在发动机出现异响时,仍高速行车,致使发动机发生捣缸事故。由于这种发动机的连秆螺栓的螺母是靠拧紧力矩在螺母自身产生的弯矩作用下达到自锁的。在维修中,拆卸螺栓、螺母后,应更换新件, A Shanghai Santana LX sedan, the driving rod actually drilled out of the cylinder. After checking the connecting rod bolt problem. The possible causes of the accident are twofold: First, the repairman in the repair of JV-type engine, did not require the replacement of connecting rod bolts and nuts, or not according to the required torque to tighten the connecting rod nut; Second, the driver carelessness, at When the engine abnormal noise, still driving at high speed, resulting in the engine pounding cylinder accident. Since the nut of the stalk bolt of the engine is self-locking under the action of the bending moment generated by the nut by the tightening torque. In the maintenance, removal of bolts, nuts, should be replaced with new pieces,