锁紧螺母扭矩设计与重复使用特性研究

A Study of Torque Design and Reusability of Prevailing Torque Nuts

针对目前有效力矩型锁紧螺母研究中缺乏完善的扭矩设计方案,分析锁紧螺母工作原理,在普通螺纹紧固件扭矩-夹紧力公式的基础上建立修正公式,通过拧紧试验和数据整理分析,确定扭矩设计方案。同时结合反复拧紧-振动试验、反复拧入拧出试验和理论分析,研究锁紧螺母重复使用特性问题。研究结果表明:压扁收口自锁螺母重复使用次数在5次以内,尼龙自锁螺母重复使用40次,螺母仍能保证足够的防松性能。但尼龙自锁螺母重复使用超过20次以后,需适当加大初始拧紧扭矩,超过40次则不推荐继续使用。研究结果对于锁紧螺母的扭矩设计及使用有一定的指导意义。

At present, there is lack of comprehensive design scheme of prevailing torque nuts, analyze working principle of those fasteners, establish revised formula based on ordinary thread fasteners＇ torque-clamping force formula, by tightening test and data analysis, obtain torque design scheme. Combined with repeated tightening-vibration test, repeated tightening- loosening test and theoretical analysis, research reusability of prevailing torque nuts. The results show that the reuse number of distorted thread all-metal nuts should be less than 5 while nylon insert nuts are 40, to guarantee the anti-loosening characteristics. Nylon insert nuts should increase tightening torque appropriately beyond 20 reuse and should not reuse beyond 40. The results provide reference for the design and application of prevailing torque nuts.