CFRP砂轮与钢基体砂轮高速磨削过程中的动力学特性

为探究CFRP砂轮与钢基体砂轮在高速磨削过程中的动力学特性，在数控凸轮轴磨床上搭建振动测试试验平台，开展磨削过程的动力学特性试验，研究2种砂轮在不同线速度和不同进给速度下的振动信号变化，并测量磨削后工件的表面粗糙度。结果表明:CFRP砂轮主轴系统的各阶固有频率高于钢基体砂轮主轴系统的各阶固有频率，且磨削过程中激发的优势频率处于高频区域。随着砂轮线速度的增大，GCr15工件表面粗糙度随之发生波动，CFRP基体砂轮磨削表面的粗糙度明显变小，较钢基体砂轮磨削表面的粗糙度减小30%～35%。颤振发生前后，CFRP基体砂轮磨削的表面粗糙度由0.089 μm变为0.091 μm，粗糙度增大2.2%；钢基体砂轮磨削的表面粗糙度由0.135 μm变为0.146 μm，粗糙度增大8.2%。在线速度一定的条件下，随着砂轮进给速度的增加，CFRP砂轮和钢基体砂轮磨削的工件表面粗糙度值都有增加，分别为2.4%和2.9%，但相较于砂轮线速度对工件表面粗糙度值的影响，进给速度对工件表面粗糙度值的影响更小。 

Dynamic characteristics of high speed grinding process of CFRP wheel and steel based wheel

To explore the influence of CFRP grinding wheel and steel substrate grinding wheel on the dynamic characteristics of high-speed grinding process, a vibration test platform was built on the CNC camshaft grinding machine, and the dynamic characteristics of grinding process were carried out.The vibration signal changes of two kinds of grinding wheel under different linear speeds and different feed speeds were compared.The surface roughness of workpiece after grinding was measured.The results show that the natural frequencies of the spindle system of CFRP grinding wheel are lower than those of the spindle system of steel matrix grinding wheel, and the dominant frequencies excited in the grinding process are in the high frequency region.With the increase of the linear speed of the grinding wheel, the surface roughness of the GCr15 workpiece fluctuates.The grinding surface roughness of the CFRP based grinding wheel is obviously smaller, which is 30%~35% less than that of the steel based grinding wheel.Before and after chatter, the surface roughness of CFRP grinding wheel changed from 0.089 μm to 0.091 μm, increasing by 2.2%.The surface roughness of steel grinding wheel changed from 0.135 μm to 0.146 μm, increasing by 8.2%.When the line speed is confirmed in a range, with the increase of feed speeds, the surface roughnesses of CFRP grinding wheel and steel substrate grinding wheel both increase, increasing by 2.4% and 2.9%, respectively.However, compared to the influence of line speed on surfaceness, the feed speed has relatively small influence on surface roughness.