一种临时紧固件及其预紧力测量方法

A measurement method for temporary fastener and its preload force

薄壁件在正式装配前一般需要通过临时紧固件进行定位和夹紧,定位和夹紧的质量直接影响薄壁件的后续工艺质量,乃至最终的薄壁件产品质量,而临时紧固件的夹紧力和预紧力又是影响装配质量关键之中的关键。文中提出了一种能够测量临时紧固件预紧力的方法,该方法通过在临时紧固件内设置成组碟形弹簧片,来扩大临时紧固件在受力时产生的变形量,该变形量将被倚靠在内六角扳手上的压缩弹簧感知,进而被紧邻压缩弹簧的力传感器感知,所以,临时紧固件所受预紧力最后通过碟形弹簧片受力与变形之间的关系反推。内六角扳手的另一端通过套筒联轴器与电机连接,内六角扳手的轴向位移量在套筒联轴器内部补偿,从而实现了临时紧固件的自动化装配与同步预紧力的测量,最终得出了配合M4临时紧固件使用的碟形弹簧片的参数、组合方式,以及监控预紧力时的变形范围。

The thin-walled parts generally need to be positioned and clamped by the temporary fasteners before formal assembly.The quality of positioning and clamping directly affects the subsequent process quality of the thin-walled parts,and even the quality of the final assembled products.The temporary fasteners'clamping force and preload force are key to the assembly quality.In this article,a method of measuring the temporary fastener's preload force is proposed.The deformation is expanded when the temporary fastener is subjected to a preload force by inserting a group of the Belleville springs.The deformation is sensed by the compression spring leaning on the hexagonal wrench,and then by the force sensor adjacent to the compression spring.Therefore,the preload force exerted to the temporary fastener is finally inferred by the relationship between the force and the deformation of the Belleville spring.The other end of the hexagonal wrench is connected to the motor through a sleeve coupling,and the axial displacement of the hexagonal wrench is compensated inside the sleeve coupling.As a result,the automated assembly of the temporary fasteners is simultaneous with the measurement of the preload force.Finally,efforts are made to work out the parameters and the combination method of the Belleville springs used with the M4 temporary fastener,as well as the deformation range of the disc springs(Belleville spring washers)when monitoring the preload.