Consideration of functionally relevant geometric deviations in the design of metal forming processes for the production of gears by extrusion

研究小组的总体目标是实现一个集成的、面向过程的公差管理。在此框架内，在分配公差时，不仅需要考虑与工艺相关的几何部件偏差原因，还需要考虑由操作引起的偏差。拟议子项目的目的是确定在金属-塑料材料配对中对冷锻齿轮的操作行为的影响变量，并推导出与工艺相关的部件特性与由此产生的磨损行为之间的功能相关性。在此基础上，对生产现成齿轮的挤压工艺进行了操作优化设计，以确保在使用寿命期间符合与功能相关的公差。在第一个供资期间获得的知识构成了计划工作的重要基础。在第一个资助阶段，确定了与工艺相关的控制杠杆以及工艺变化对冷锻钢齿轮几何和机械性能的影响。在第二个资助期，将研究挤压齿轮的部件性能对几何偏差的影响，这是由于金属-塑料材料配对在运行中的特征磨损行为。根据导出的数据，子项目合作伙伴创建元模型来描述磨损行为，并将其应用于公差分析。发生的齿磨损限制了对功能相关公差的遵从性以及配对的寿命。第一阶段的初步调查表明，挤压过程中与应用相关的组件特性的有针对性的影响有可能显著改善配对的操作行为。随着子项目目标的实现，研究协会对面向过程的公差分配进行了决定性的研究成果处理。了解与生产相关的组件属性和操作行为之间的功能相关性，可以实现更有效的产品和流程设计。此外，齿轮的面向过程的公差优化支持设计和测量技术在定义各自的要求。在与其他子项目的合作中，这有助于减少开发和评估成本并缩短产品发布时间。

The overall objective of the research group is to achieve an integrated, process-oriented tolerance management. Within this framework, it is necessary to consider not only the process-related causes for geometric component deviations, when assigning tolerances, but also the deviations resulting from operation. The aim of the proposed subproject is to identify influencing variables on the operational behaviour of cold-forged gears in the metal-plastic material pairing and to derive functional correlations between the process-related component properties and the resulting wear behaviour. Based on this, an operationally optimized design of the extrusion process for the production of ready-to-use gears is to be carried out in order so ensure compliance with the function-relevant tolerances over the lifetime.The knowledge gained in the first funding period forms an essential basis for the planned work. In the first funding period the influence of process-related control levers as well as process variations on the geometric and mechanical properties of cold-forged steel gears were determined. In the second funding period, the effects of the component properties of extruded gears on geometric deviations due to the characteristic wear behaviour of the metal-plastic material pairing in operation will be investigated. Based on the derived data, the subproject partners create metamodels to describe the wear behaviour and apply them for tolerance analysis. The occurring tooth wear limits the compliance with the function-relevant tolerances as well as the lifetime of the pairing. Preliminary investigations of the first phase show that a targeted influence of the application-relevant component properties in the extrusion process has the potential to significantly improve the operating behaviour of the pairing.With the achievement of the objective of the subproject, the research association disposes of decisive findings for process-oriented tolerance allocation. The knowledge of functional correlations between the production-related component properties and the operational behaviour enables a more efficient product and process design. In addition, the process-oriented tolerance optimization of the gear supports both the design and the measurement technology in the definition of the respective requirements. In cooperation with the other subprojects, this contributes to reduce development and evaluation costs and shorten product launch times.