基于砂轮进给率和磨削功率的内圆磨削系统分析

Internal Grinding System Analysis Based on Grinding Wheel Feed Rate and Grinding Power

分析了将砂轮进给率做为输入参数和磨削功率做为输出参数的内圆磨削系统的动态模型及其传递函数。基于该系统的结构和组成环节,首先确定了系统模型,然后将在不同砂轮进给率下实测的两组功率数据用于系统分析,其中的一组数据用于系统参数的识别,另一组用于验证所识别的参数。以数控化改造的内圆磨床为例,采用ARX和ARMAX方法来识别系统参数,将进给率做为输入、磨削功率做为输出的参数传递路径,分析识别内圆磨削过程的系统传递函数,用于分析数控化改造内圆磨床的稳定性和仿真系统的输出功率的变化规律;通过功率谱密度函数分析磨削过程的系统误差和工件毛坯偏差。分析结果表明输出信号中的干扰(噪声)来源于被磨工件内圆表面的偏心和表面波纹。该分析结果可用于内圆磨削选择进给率参数、分析磨削系统和磨削表面质量的依据。

With wheel feed rate as the input parameter and grinding power as the output parameter,the dynamic model and transfer function of internal grinding system were analyzed.The model of the system was firstly established.Two groups of power data were tested with different grinding wheel feed rates,in which one group was used to identify the systematic parameters and the other was used to validate them.A CNC internal grinder was selected as an example.Its systematic parameters were identified with ARX and ARMAX methods.A parameter transfer channel was set up with feed rate as the input and grinding power as the output,by which the transfer function of internal grinding system was analyzed so as to investigate the stability of the grinder and the changing law of the power of the simulation system.With the power spectral density function,the systematic error and deviation of work piece blank in the grinding process were discussed.The results show that interference（noise） in the output signal of comes from the eccentric and surface waves of the inner surface of the work piece that is ground.This result is helpful to define the feed rate,analyze internal system and appreciate the surface grinding quality in internal grinding.