论文部分内容阅读
对于自动获得尺寸的内圆磨床来说,热变形是一种重要的系统性误差来源。由于机床的热源众多,结构复杂,使变形状态也非常复杂,增加了温升及变形计算上的困难。本文应用多级发热理论近似地解决上述计算问题,并推导出由热变形所引起的加工误差的计算公式。文中还应用尺寸链原理分析了M228半自动内圆磨床在磨削过程中的机床热变形对加工精度的影响。机床温升、温度场及热变形量的测定结果表明,整台机床有较大的温差,主要热源是液压部件及磨杆轴承,由于床身及磨杆等部件同时热变形,使主轴及磨杆的相对位置在受热过程中远离,因而使工件尺寸趋大。这与实验尺寸点图是一致的。为了降低甚至消除热变形的影响,将床身下部的油箱移出机床,并隔绝油缸的热影响,结果床身热变形以及系统性误差大大降低。通过实验,证实了上述误差分析和计算方法是正确的。所采取的消除热变形的措施是有效的。可以作为改进机床设计的参考。
Thermal deformation is an important source of systematic error for automatically sized internal grinders. Due to the large number of heat sources, complex structure, deformation of the state is also very complex, increasing the temperature rise and deformation of the difficulties. In this paper, the multi-level heating theory is applied to solve the above calculation problem and the calculation formula of machining error caused by thermal deformation is deduced. The article also uses the dimension chain principle to analyze the M228 semi-automatic internal grinding machine in the process of grinding machine heat distortion on the machining accuracy. The measurement results of temperature rise, temperature field and thermal deformation of the machine tool show that the whole machine tool has large temperature difference, the main heat source is the hydraulic components and the grinding rod bearing. Due to the simultaneous thermal deformation of the bed body and grinding rod and other components, The relative position of the rod away from the heating process, thus increasing the size of the workpiece. This is consistent with the experimental size point map. In order to reduce or even eliminate the effect of thermal deformation, the lower part of the bed of the tank removed from the machine and isolated from the thermal effects of the cylinder, resulting in thermal deformation of the bed and the systematic error is greatly reduced. Through experiments, it is confirmed that the above error analysis and calculation method is correct. The measures taken to eliminate thermal deformation are effective. Can be used as a reference to improve machine design.