Compensation of Shape and Dimensional Deviations Due to Thermo-Elastic Deformation During Dry Machining

干式加工过程中热弹性变形引起的形状和尺寸偏差的补偿

• 批准号: 426824785
• 负责人: Professor Dr.-Ing. Thomas Bergs
• 金额: --
• 依托单位: Werkzeugmaschinenlabor - WZL
• 依托单位国家: 德国
• 项目类别: Research Grants (Transfer Project)
• 财政年份: 2019
• 资助国家: 德国
• 起止时间: 2018-12-31 至 2020-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/426824785?language=en
• 关键词: Compensation; Shape; Dimensional; Deviations; Due

In conjunction with the further development of cutting materials in manufacturing technology, it is now possible in many applications to completely dispense with cooling lubrication of the cutting tool or to use only minimum quantity lubrication. In this way, it is feasible to save costs for the provision, maintenance and disposal of various cooling lubricants.The elimination of cooling lubricants during dry machining, however, causes a change in the process heat generated and its distribution within the thermodynamic system, consisting of tool, workpiece, chips and the machine tool environment. The occurring heat flows cause a deformation of the workpiece and an undesired displacement of the machine components. This results directly in deviations in shape and dimension of the manufactured workpieces, which is why process design is much more complex than using conventional cooling lubrication. Due to the temporal and spatial complexity of the physical process involved, the deformations that occur cannot yet be compensated by simple analytical calculations or empirical knowledge.The overriding goal of the transfer project is therefore to implement the compensation of thermo-elastic deformations on the basis of a real application case for the first time and thus to transfer it into industrial practice. For this, it is necessary to extend already developed methods by the thermo-elastic displacement of the tool. Subsequently, strategies for the compensation of such misalignments and deformations can be derived, which enable dry hard turning of complex components with high demands on shape and dimensional accuracy.The multi-scale procedure developed in the DFG research project "Development of a model for the calculation and compensation of thermo-elastic shape and dimensional errors during dry machining" enables the heat flows in the equilibrium state of a turning process to be calculated on a mesoscopic scale by means of a chip formation simulation and to be transferred to a macroscopic component model for the calculation of heating and ultimately thermo-elastic deformation. In the basic research project of the SPP 1480, the suitability of this approach for the precise and time-efficient calculation of the thermo-elastic deformations of a workpiece could be proven. This calculation forms the basis for deriving a compensation strategy to avoid dimensional and shape errors.

随着制造技术中切削材料的进一步发展，现在在许多应用中可以完全免除切削刀具的冷却润滑或仅使用最少量的润滑。这样，就可以节省各种冷却润滑剂的提供、维护和处置成本。然而，在干式加工过程中，冷却润滑剂的消除会导致产生的过程热量及其在热力学系统内的分布发生变化，热力学系统由工具、工件、切屑和机床环境组成。发生的热流引起工件的变形和机器部件的不希望的位移。这直接导致制造工件的形状和尺寸的偏差，这就是为什么工艺设计比使用传统的冷却润滑要复杂得多。由于所涉及的物理过程的时间和空间复杂性，所发生的变形还不能通过简单的分析计算或经验知识来补偿。因此，转移项目的首要目标是首次在实际应用案例的基础上实现热弹性变形的补偿，从而将其转化为工业实践。为此，有必要通过工具的热弹性位移来扩展已经开发的方法。随后，可以推导出补偿这种错位和变形的策略，从而实现对形状和尺寸精度要求高的复杂部件的干硬车削。DFG研究项目“开发用于计算和补偿干式加工过程中热弹性形状和尺寸误差的模型”中开发的多尺度程序使车削过程平衡状态下的热流通过切屑形成模拟在细观尺度上计算，并转移到宏观组件模型中用于计算加热和最终的热弹性变形。在spp1480的基础研究项目中，验证了该方法对工件热弹性变形的精确、快速计算的适用性。这种计算构成了推导补偿策略以避免尺寸和形状误差的基础。