PMAC时基控制在非圆零件数控车削加工中的应用

Application of PMAC time-base control in the NC machining of noncircular section parts

为了防止在高温、高压下工作的活塞发生敲缸和拉缸,提高其使用寿命和工作性能,活塞常被设计成中凸变椭圆.然而,中凸变椭圆的活塞给实际制造带来了很大困难.针对中凸变椭圆活塞数控车削加工对数控系统高实时性要求,构建了基于可编程多轴控制器PMAC(Program Multiple Axises Controller)的非圆截面活塞车削数控系统,其中采用了直线电机作为横向进给机构,数控系统采用了PMAC+IPC的双CPU的结构方案,将控制系统的开发平台直接构筑于IPC的软硬件之上且应用PMAC的时基控制功能代替传统的硬靠模.并在基于直线电机驱动的数控车床上编制了椭圆截面的数控加工程序,实现了该类零件的数控车削加工.

In order to prevent piston from knock and cylinder score, modern pistons with convex contour and vail-elliptical cross-section are designed, which can prolong piston longevity and enhance engine performance. Considering the high performance and real-time requirement for CNC （Computer Number Control） system in the process of machining of the middle-convex and vail-elliptical piston, the CNC system based on PMAC （Program Multiple Axises Controller） is designed. The system is an open double CPUs architecture with PMAC and industry IPC. The principle of PMAC time-base control is described. The turning program of ellipse parts is compiled on the CNC lathe in terms of the linear motor. Through this method, the turning machining of ellipse parts has been achieved.