Direct correction of thermo-elastic deformations

热弹性变形的直接校正

• 批准号: 419982228
• 负责人: Professor Dr.-Ing. Christian Brecher
• 金额: --
• 依托单位: Forschungsbereich Werkzeugmaschinen
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2019
• 资助国家: 德国
• 起止时间: 2018-12-31 至 2021-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/419982228?language=en
• 关键词: Direct; correction; thermo; elastic; deformations

According to VDI/DGQ 3441 the production accuracy, the machining accuracy and the geometrical accuracy are a matter of concern for the majority of machine tools. The geometrical accuracy of a machine tool is the accuracy with that any position in the volume can be approached. It depends on the geometrical deviations between the axes and of the single axis itself. The cartesian deviations of the tool center point (TCP) from its required position can explicitly be described by a model of the kinematic chain and the errors defined in ISO 230-1.To increase the geometrical accuracy of machine tools their geometry is measured and corrected by the control system of the machine after the bringing into service. Under operating conditions, the measured errors are superposed by static, dynamic and non-steady thermo-elastic errors. The thermo-elastic errors represent up to 75% of the total error. The presented project focusses on these errors.Beside machine internal heat sources and sinks thermal influences of the environment induce heat flows into the structural components of the machine. Depending on the thermal material characteristics, such as heat capacity, mass distribution and position of the heat sources, an irregular and non-stationary temperature field is formed. Together with the elongation lengths, their elongation coefficients, the part structure, the position of the parts to each other and the type and installation of the position measurement system, deviations and inclinations of the machine structure result from this temperature field. Hence, the resulting TCP deviation is highly pose dependent.If high changes of the thermal state of the machine tool occur after the measurement, the errors can increase, leading to a higher deviation of the TCP from its required position. Subsequently the part quality decreases. A process actual measurement of the geometrical errors could help to deal with this problem. Measured machine errors are in the case of this proposal process actual, if they are acquired a few minutes before the final cut.Up to now, there is no state of the art technology available in science and industry that is able to measure the geometrical errors of small and medium machining centers process actually. The aim of the presented research project is the validation of such a measurement method. On top, a method for the direct compensation of the measured deviation shall be validated.

根据VDI/DGQ 3441的生产准确性，加工精度和几何精度是大多数机床的问题。机床的几何准确性是可以接近音量中的任何位置的精度。它取决于轴和单轴本身之间的几何偏差。工具中心点（TCP）与所需位置的笛卡尔偏差可以通过运动链的模型明确描述，以及在ISO 230-1中定义的误差。为了提高机床的几何准确性，它们的几何形状得到了测量和校正通过机器的控制系统，在使用后。在工作条件下，测得的误差被静态，动态和非稳态的热弹性误差所超大。热弹性误差最多代表总误差的75％。提出的项目重点放在这些错误上。BesideMachine内部热源和沉降环境的热影响会引起热量流入机器的结构组件。根据热材料特性（例如热容量，质量分布和热源的位置），形成了不规则和非平稳温度场。连同伸长长度，其伸长系数，零件结构，零件的位置，以及位置测量系统的类型和安装，机器结构的偏差和倾斜度来自此温度场。因此，所得的TCP偏差是高度姿势依赖性的。随后，零件质量降低。过程的实际测量几何错误可能有助于解决这个问题。实际的机器错误是实际的，如果在最终削减之前几分钟被收购。实际上是中小型加工中心的过程。提出的研究项目的目的是验证这种测量方法。最重要的是，应验证直接补偿测量偏差的方法。