钛合金铆钉热铆一次合格率提升方法研究

Study on Method for Raising Hot Riveting Qualification Rate of Titanium Alloy Rivet

针对现有钛合金铆钉热铆存在的镦头成型不足、镦头表面灼伤、钉头现灰黄色氧化层等问题,分析得出其主要原因是铆接加热时间未精确控制和铆接过程带电,提出了一种钛合金铆钉热铆系统优化方法,基于PLC实现加热时间参数化控制和铆接自动断电功能,通过铆钉加热试验获得多组铆钉温度和对应加热时间数据,采用牛顿插值法得到铆钉加热至目标温度时所需加热时间,形成一套针对不同长度和直径铆钉的热铆工艺参数,最后通过热铆试验确定钛合金铆钉热铆一次合格率获得大幅提升。

Aiming at the problems existing in hot riveting of titanium alloy rivets,such as insufficient forming of rivet upsetting head,surface burns of rivet upsetting head and rivet head oxidation,the main reason was found to be inaccurate control of riveting heating time and electriferous riveting process.An optimization method of hot riveting system for titanium alloy rivets was proposed.The function of heating time parametric control and automatic power cut-off before riveting was realized based on PLC.Data of rivet temperature and corresponding heating time were obtained by rivet heating test.Heating time required for rivet to reach target temperature was obtained through Newton interpolation method.A set of hot riveting process parameters for rivets of different lengths and diameters was formed.Finally,the qualified rate of hot riveting of titanium alloy rivets was greatly improved through the hot riveting test.