螺纹紧固件拧紧扭矩的确定方法研究

为在满足使用要求的情况下充分发挥螺纹紧固件的效能,提出了拧紧扭矩计算的预紧力-扭矩特性曲线法。分析过程中,通过理论推导和实验分析,得到了在拧紧过程中等效拉应力与实际拉应力的关系式;并得到了当螺纹紧固件在拧紧至屈服之前,螺纹摩擦扭矩与拧紧总扭矩之比不变的结论。运用预紧力-扭矩特性曲线法对某汽车发动机承重螺栓的拧紧扭矩进行计算,通过与实际扭矩值进行比较,表明该方法更能发挥螺栓的使用效能。

Study of Method to Determine Tightening Torque of Thread Fasteners

To meet the operating requirements and give full play to the efficiency of thread fasteners in the same breath, the paper puts forward a pre-tightening force-torque characteristic curve to calculate tightening torque. In the analytical process, through the theoretical calculation and the experimental analysis, the equation accounting for rela- tionship between the equivalent tension stress and the actual tension stress is obtained. It reveals that before tightening to the yield, the ratio of thread friction torque and total torque is constant. Furthermore, after calculating the tightening of a car engine＇s bearing bolts by pre-tightening force-torque characteristic curve method, and comparing the results and the practical torque value, it concludes that the pre-tightening force-torque characteristic curve method can better develon efficiency of the bolt.