Lei Pengli, Wang Zhenzhong, Shi Chenchun, Peng Yunfeng, Lu Feng
Department of Mechanical and Electrical Engineering, Xiamen University, Xiamen 361005, China.
Micromachines (Basel). 2021 Nov 25;12(12):1445. doi: 10.3390/mi12121445.
Hydrostatic guideways are widely applied in ultra-precision machine tools, and motion errors undermine the machining accuracy. Among all the influence factors, the thermal effect distributes most to motion errors. Based on the kinematic theory and the finite element method, a 3-degrees-of-freedom quasi-static kinematics model for motion errors containing the thermal effect was established. In this model, the initial state of the closed rail as a "black box" is regarded, and a self-consistent setting method for the initial state of the guide rails is proposed. Experiments were carried out to verify the thermal motion errors simulated by the finite element method and our kinematics model. The deviation of the measured thermal vertical straightness error from the theoretical value is less than 1 μm, which ensured the effectiveness of the model we developed.
液体静压导轨在超精密机床中得到广泛应用,而运动误差会影响加工精度。在所有影响因素中,热效应是导致运动误差的主要因素。基于运动学理论和有限元方法,建立了包含热效应的三自由度准静态运动误差运动学模型。在该模型中,将封闭导轨的初始状态视为一个“黑箱”,并提出了一种导轨初始状态的自洽设定方法。通过实验验证了有限元方法和运动学模型模拟的热运动误差。实测热垂直直线度误差与理论值的偏差小于1μm,验证了所建模型的有效性。