Abstract:

In order to improve the machining precision,surface quality and processing efficiency of a camshaft,a theoretical model of constant linear velocity grinding process of the camshaft was established according to the X-C axis linkage motion principle of grinding machine.Based on this theoretical model,a numerical calculation model of grinding speed optimization and regulation was also built by means of cubic spline fitting interpolation method.Combined with the specific camshaft part and the real parameter of the grinding process plan,the processing motion data of  the all grinding machine kinematic axises were calculated.And then the motion data were changed automatically into NC processing program of specified numerical control system under the conditions of no process faults.Thereby the automatic NC programming of camshaft grinding was realized.At last,one experiment was done on a NC high speed camshaft grinding machine,CNC8312A.In this experiment,the admission cams and the exhaust cams of Qianjiang 32F camshaft were ground separately,and the expected machining effects were also achieved.With the experimental evidence,it is shown that the methods of the grinding speed optimization and regulation and automatic NC programming are feasible whether theoretically or practically.And the methods meet the needs of the practical camshaft production well.

Key words: camshaft, grinding process, grinding speed, speed optimization, speed regulation, automatic NC programming

摘要：

为进一步提高凸轮轴的加工精度、表面质量和加工效率,根据X-C轴联动磨床的运动原理，建立了凸轮轴恒线速加工理论数学模型，依据该数学模型采用三次样条拟合插值法，建立了凸轮转速优化调节的数值计算模型。结合具体凸轮轴零件及其磨削加工工艺方案的具体参数，计算出机床各运动轴加工过程的运动数据，在确保无工艺故障的前提下，最终把各轴的运动数据自动转换为对应数控控制系统的数控加工程序,从而实现了凸轮轴磨削的自动数控编程。最后在CNC8312A数控高速凸轮轴磨床上，对钱江32F型号凸轮轴的进气凸轮和排气凸轮分别进行磨削加工试验,得到了预期加工效果。试验验证表明,该加工速度优化调节及其自动数控编程方法在理论上和实践上都是可行的，完全满足实际生产的需要。

关键词: 凸轮轴, 磨削加工, 加工速度, 速度优化, 速度调节, 自动NC编程