Basic study on speed-stroke grinding with linear motor driven table system

为了在平面磨削中实现高的材料去除效率，提出了速度冲程磨削的概念。采用直线电机驱动的转台系统，实现了转台系统的高速、高加速度往复运动。其最大加速度为0.7g，最大速度为60m/min，远高于传统的液压驱动转台系统。作为第一阶段的研究，测试了转台运动的精度，如定位精度、俯仰和偏航。此外，还对转台往复运动引起的主轴头强迫振动进行了详细的测量。利用直线电机，优化了工作台运动的加减速方式，减小了振荡力。这种方法是非常成功的，并通过应用加速度的正弦模式抑制了强迫振动。在对磨床进行性能测试的基础上，进行了一系列磨削试验。该工艺的性能指标为磨削力、温度、表面粗糙度和砂轮磨损。所选的工件材料为钢和工程陶瓷。通过磨削试验，证实了速度冲程磨削能有效地降低磨削力，同时磨削温度保持材料去除速率不变，即在减小切深的同时提高工件速度，可显著降低磨削力。这对于难加工材料的磨削特别有利。

In order to achieve high material removal rate in surface grinding, the concept of speed-stroke grinding was proposed. High speed and high acceleration in reciprocating motion of the table system were attained by applying the linear motor driven table system. The maximum acceleration and speed attained were 0.7G and 60 m/min, respectively, which are much higher than the conventional hydraulic driven table system.As the first phase of the study, accuracy of the table motion, such as positioning accuracy, pitching, and yawing were measured. In addition, forced vibration of the spindle head induced by the table reciprocation was carefully measured. Taking advantage of the linear motor, acceleration and deceleration patterns of the table motion were optimized for reducing the oscillation force. This approach was quite successful and the forced vibration was suppressed by applying the sinusoidal patterns of the acceleration. As the result, it was confirmed that the planed performance of the grinding machine was achieved.Following the performance test of the grinding machine, a series of grinding tests was conducted. Performance indexes of the process were, grinding force, temperature, surface roughness, and grinding wheel wear. Selected workpiece materials were steel and engineering ceramics. Through the grinding tests, it was confirmed that the speed-stroke grinding was effective for reducing the grinding force as well as grinding temperature keeping the material removal rate constant, I.e., by increasing the workpiece speed while reducing the depth of cut, grinding force can be significantly reduced. This is particularly advantageous for grinding of difficult to machine materials.