40Cr直齿齿条齿形加工方法优化研究

Research on the Machining Method Optimization of 40Cr Spur Gear Rack

直齿齿条齿形加工传统需要采用粗铣+精铣的工艺方法,以避免加工出现变形,影响精度,但加工效率低。因此针对40Cr直齿齿条齿形加工工艺进行优化研究,实现了齿形一次加工成型。首先,通过在齿形加工前增加粗铣及低温热时效处理,降低了调质处理产生的内应力,避免了后续齿形成形加工时发生变形;其次,通过自行设计加工平台,提高平台高度,降低了主轴伸出长度,解决了主轴在齿形加工时切削力较大情况下刚性不足的问题;对不同厂家齿形铣削刀具进行试验,结果表明,采用瓦尔特PLNE220905N-D298-GA4230成形刀具,切削扭矩较低,加工时机床不会出现振动。在此基础上对加工参数进行研究,结果表明,在转速为200r/min、进给量为300mm/min的情况下,齿形表面粗糙度可达Ra3.2μm。

Traditionally,for avoiding the machining deformation and affecting precision,the toothprofile machining process adopted spur gear rackis rough milling and finish milling,which was low processing efficiency.Consequently,aimed at optimizing the machining process of 40Cr spur gear rack,realized one-time machining forming of the toothprofile.Firstly,before the tooTHprofile machining,rough milling and low temperature heat aging were used to reduce the quenching and tempering stress and avoiding machining deforming.Secondly,the machine tool spindle rack of low rigidity wiTHbig cutting force was solved by means of enhancing the platform height and lowing spindle length.Thirdly,machining test program for the different milling cutter was carried out,and the results showed that when using Walter PLNE220905N-D298-GA4230 form cutter,the cutting torque was lower and machine tool would not vibrate.On basis of that,researched machining parameters,the results showed that when revolving speed was 200 r/min and speed feed was 300 mm/min,the roughness of toothprofile can be Ra 3.2μm.