电子驻车制动系统粉末冶金斜齿轮的开发

作为电子驻车制动系统中涡杆传动的关键零件,粉末冶金斜齿轮因其内孔为非圆形花键,结构复杂,成型难度大。为解决这一问题,本文讨论了粉末冶金斜齿轮的结构特点和力学性能,分析了齿轮材料的选择,并研究了生产工艺流程。研究结果表明:应选用流动性较好的粉末材料保证粉末在阴模的斜齿区域均匀填充;为避免花键结构的芯棒受力过大而断裂,选择下模不旋转即可成型斜齿轮的压机;根据产品要求,生产工艺流程设计如下:压制→烧结硬化→回火→后处理,其中,零件的压制成型和烧结硬化技术是重点。通过对斜齿轮生产工艺的精心策划和过程质量的严格管控,开发出符合实际工况要求、高精度、高强度、结构复杂的电子驻车制动系统用粉末冶金斜齿轮,该斜齿轮目前已经实现批量生产,质量稳定可靠,取得了较好的经济效益。

Development of powder metallurgy helical gear used in electronic parking brake system

As the key part of turbine drive in the electronic parking brake system, the powder metallurgy helical gear was difficult to form because of the non-circular spline structure of inner hole. The structure, performance, material selection, and production process of powder metallurgy helical gear were introduced in this paper. In the results, the well-fluidity powder should be used to fill the helical region of female die. To avoid the fracture of core rod, the pressing machine with non-rotation lower punch is selected. According to the product requirements, the production process is as follows: compacting→ sintering hardening→ tempering→ postprocessing; the compacting and sintering hardening are the key steps. By applying the applicable technology, the high-accuracy, high-strength, and complex-shaped helical gear can be produced, meeting the demand of working condition.The helical gear has been quantity production in stable quality, getting good economic benefits.