基于运动学与动力学分析的极坐标超声振动端面微磨削机理研究

Polar Coordinates Ultrasonic Vibration End Micro- grinding' Grain Trajectory Modeling and Its' Simulation

提出了一种极坐标式超声振动端面微磨削加工方法,建立微砂轮端面最外层圆周上磨粒运动轨迹模型,并采用对时间求导与矢量合成的方法,推导出磨粒的速度模型和加速度模型。针对超声振动方向和微砂轮进给方向之间的夹角Φ,进行了单因素仿真试验研究。结果表明:磨粒轨迹具有周期性和方向性,邻近轨迹存在交叠和分离特征,证明微磨削加工中存在"沟槽宽化"、"断续切削"等现象;磨粒速度最大值呈现稳定变化趋势,但其方向受Φ影响较为显著;磨粒加速度大小仅由所施加的超声振动参数决定,其方向受Φ影响较大;磨粒的高频冲击力远大于材料的许用应力值,利于材料的疲劳去除。

In this paper, a polar coordinates type end micro ultrasonic vibration grinding method, and establish the micro grinding wheel end face grinding grain on the outer circumference of the trajectory model; with the method of derivation and vector synthesis of time, abrasive particle velocity model and acceleration model is deduced. Based on the above model, in view of the ultrasonic vibration direction and the angle between the direction of feed Ф micro grinding wheel, has carried on the simulation test of single factor analysis. Results show that the particle trajectory is cyclical and direetivity, adjacent tracks are overlapping and separation features, for ＂ the machining of the groove width ＂ , ＂ interrupted cutting＂ phenomenon such as provides strong evidence; abrasive particle velocity maximum stable trend, but the direction is influenced by Ф significantly ; imposed by the size of particle acceleration only by the ultrasonic vibration characteristics of the decision, and greatly influenced by Ф direction; In addition, the high frequency of abrasive particle impact is greater than the material allowable stress value and benefit for the fatigue of the material removal.