【摘要】 环境温度作为影响并联机床加工精度的误差源一直被忽视,为提高机床的加工精度,研究了环境温度影响下并联机床的误差分布特性。用全微分法建立机床的误差模型,根据该模型计算工作空间内各点的径向误差和轴向误差,用Matlab绘制各误差的空间分布图及各离散层上的误差等值图,得到了各误差的分布形态及分布规律,并对误差分布规律进行了试验验证。研究表明,径向误差主要受刀轨半径的影响,轴向误差受刀尖点轴向坐标和刀轨半径的共同影响。工作空间边缘区域径向误差较大,向中心区域递减;轴向误差反之。提出误差等值图可用来分析和估算环境温度对并联机床加工误差的影响。更多还原

【Abstract】 Ambient temperature as an error source affects parallel machine tool’s machining accuracy has been neglected. In order to improve the machining accuracy,error distribution characteristics of cross-legged parallel machine tool under the influence of ambient temperature were investigated. A position-pose error model of parallel machine tool was set up by means of complete differential. Radial error and axial error of each point in the workspace were calculated according to the model. Spatial distribution map and error contour maps were drawn using Matlab. Thus,every error’s distribution pattern and law were gotten. And,the error distribution law was verified through a contrast experiment. Research shows that radial error is mainly affected by tool path radius,and axial error is affected by both tool central point’s axial coordinate and tool path radius. Radial error shows a decreasing trend from the edge region of workspace to the central region; axial error is opposite with it. The error contour maps can be used to analysis and estimate the influence of ambient temperature on parallel machine tool’s machining accuracy.更多还原