一维斜向超声振动辅助磨削滚动轴承钢工艺及试验研究

One Dimensional Oblique Ultrasonic Vibration Assisted Grinding for Rolling Bearing Steels and Experimental Validation

针对目前只有一维轴向、一维切向等振动方向不变的一维超声振动辅助磨削的情况,首次提出了一维斜向超声振动辅助磨削工艺方法。利用MATLAB对一维斜向超声振动辅助磨削磨粒的运动轨迹进行了模拟分析。建立了超声振动试验系统的动力学模型。通过对超声振动工作台的模态分析,研制了一维斜向超声振动辅助磨削试验系统,对不同角度下超声振动辅助磨削滚动轴承钢的磨削力及表面粗糙度值进行了研究,探究了磨削力及表面粗糙度值随超声振动方向的变化规律。多次试验结果表明,超声振动角度为67.5°附近的表面粗糙度值明显优于其他角度的表面粗糙度值,磨削力也有减小。对正交试验结果的极差分析得出:当超声振动角度为67.5°、砂轮速度为20m/s、工件速度为0.5m/min以及磨削深度为4μm时,加工后的工件表面粗糙度达到最低值,其中工件速度是影响表面粗糙度的最重要工艺参数。

Previous studies about one dimensional ultrasonic vibration assisted grinding were limited to fixed directions of ultrasonic vibration such as one dimensional axial or tangential vibration. A novel process of oblique ultrasonic vibration assisted grinding was presented. The motion paths of ab- rasive particles in oblique ultrasonic vibration assisted grinding were simulated in MATLAB. A dynamics model of experimental ultrasonic vibration system was established. Experimental devices of oblique ultrasonic vibration assisted grinding were designed through modal analysis of ultrasonic workbench. Grinding forces and surface roughnesses in grinding rolling bearing steels were studied at different directions of ultrasonic vibrations. The regulation of grinding forces and surface roughnesses with the direction of ultrasonic vibration was studied. Experimental results show that the best surface quality may be obtained when the angle of ultrasonic vibration is as 67.5° and grinding forces are also decreased. Results of orthogonal experiments demonstrate that ultrasonic vibration angle of 67.5°, wheel speed of 20 m/s, workpiece speed of 0.5 m/min, grinding depth of 4 μm are the optimum pa- rameters to obtain the best surface quality of workpiece, and the speed of workpiece has the most important impacts on the surface quality of workpiece.