汽车起动齿轮轴的精密塑性成形

The Precise Forming of Automobile Start Gear Shaft

起动齿轮轴是汽车起动机中的关键零件,头部为渐开线小模数变位内齿轮,外廓则为高经比>6的台阶轴,内齿与外台阶轴的同轴度要求较高且因下部轴长而细,所以使得塑性成形难度很大。为满足日益发展的汽车生产厂家及零配件市场的批量要求,提高汽车整车的综合性能,通过反复的工艺试验、分析、研究,制定出了一种将汽车起动齿轮轴的内齿与外台阶轴近净成形的高效精密成形技术及工艺方法,同时设计、制做了一套结构简单、新颖、寿命高的成形模具及摸架,提出了加工该高精度模具所采取的行之有效的措施。已批量生产的起动齿轮轴经工艺考核,装机试验、跑合证明:材料利用率高,生产效率高,精度高,使用寿命长,社会效益和经济效益显著。因此,该工艺技术对批量生产该类齿轮轴,具有广泛的指导意义和推广价值。

The start gear shaft is the key part of automobile starter,it is involutes small module internal gear with addendum modification;tooth surface of the internal gear is complex shape of five pleats.It is step shaft with H/D>6 in the outline.The shaft can't be machined and plastic forming also is difficult.Meeting the needs of markets and improving comprehensive function of automobiles,the high efficiency precision forming technology method of single-step chinless-forming for internal gear tooth surface and external gear tooth is put forward based on analysis,study and repeated test.In the same time,a set of high accuracy die with simple novel structure and long service life is designed and manufactured.The advantages of the method have been verified that utilization ratio of material and production efficiency is high.For this reason,the method is profitable reference for producing the same type of complex shape gear.