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

为了实现表面磨削的高材料去除率，提出了快速行程磨削的概念。采用直线电机驱动的工作台系统，实现了工作台系统的高速、高加速度往复运动。最大加速度为0.7G，最大速度为60 m/min，大大高于传统的液压驱动工作台系统。作为研究的第一阶段，测量了工作台的运动精度，如定位精度、俯仰和偏航。此外，还仔细测量了工作台往复运动引起的主轴头强迫振动。利用直线电机，优化了工作台运动的加减速模式，减小了振动力。这种方法非常成功，并且通过应用加速度的正弦模式抑制了强迫振动。结果表明，该磨床达到了预定的磨削性能。在对磨床进行性能测试后，进行了一系列的磨削试验。该工艺的性能指标为磨削力、温度、表面粗糙度和砂轮磨损。所选工件材料为钢和工程陶瓷。通过磨削试验，证实了快行程磨削在减小磨削力和磨削温度保持材料去除率恒定的情况下是有效的，即通过提高工件速度同时减小切削深度，可以显著减小磨削力。这对磨削难加工的材料特别有利。

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.