Efficient and generalized method for measurement and evaluation of thermal deviation characteristics in Multi-task machine

本研究的目的是建立多任务机床进给运动热偏差特性的测量与评价方法。本研究揭示了以下几个方面的问题。为评价Z、X方向直线运动引起的热偏差特性，研制了一套多任务机床热偏差测量系统。使用这些系统，实际评估了直线运动(X或Z轴)和摆动运动(B轴)的特性。由于这些评价结果与机器的结构形式和热源的位置相对应，因此验证了该方法的有效性。通过对测量结果和诸如机器的结构形式等信息的综合评估，可以估计热变形模式。由于这一估计结果与测试过程中在机器内某些位置测得的温度变化相对应，因此澄清了该估计的有效性。为了使该方法标准化，在两种测量系统上分别对每种运动进行了测试。结果表明：1)在Z方向使用靶标夹具，对热偏差特性进行了充分的评价；2)由于Z靶标夹具的位置对应于工件的位置，直接评价了热偏差对加工精度的影响；3)为了更清楚地评价热变形模式及其机理，有必要在Z靶标夹具的基础上进行X靶标夹具试验，并对两种试验结果进行综合评价。4)Z靶标夹具试验适合于该方法的标准化。

The purpose of this research is to establish the method for measurement and evaluation of thermal deviation characteristics caused by feed motions in Multi-task machine. The followings are revealed by this research.1. The measuring systems for evaluation of thermal deviation characteristics caused by linear motion in Z or X direction were developed for a multi-task machine. Using these systems, the characteristics were actually evaluated for liner motions (X or Z axis) and swing motion (B axis). Since these evaluation results corresponded to the structural form and the location of heat sources in the machine, the validity of this proposed method was clarified.2. The estimation of the thermal deformation mode is possible with synthetic evaluation of the measurement results and the information, such as a structural form of the machine. Since this estimation result corresponded to the temperature changes measured at some locations in the machine during the test, the validity of the estimation was clarified.3. For the standardization of this proposed method, the tests for each motion were done with two kinds of the measuring system. As the results, the followings were made clear.1) Using the target fixture in Z direction, the thermal deviation characteristics are evaluated sufficiently2) Since the location of this Z target fixture corresponds to the workpiece position, influence of the thermal deviations on the machining accuracy is evaluated directly3) To evaluate the thermal deformation mode and its mechanism more clearly, it is necessary to do the tests with the X target fixture in addition to the Z target fixture, and to evaluate the both results synthetically.4) Test with the Z target fixture is appropriate for the standardization of this proposed method.