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以过程为导向的综合宽容管理。在这一框架内，在分配公差时，不仅需要考虑与工艺有关的几何部件偏差的原因，而且还必须考虑操作造成的偏差。拟议次级项目的目的是查明影响金属-塑料材料配对中冷锻齿轮运行行为的变量，并得出与工艺有关的部件性能与由此产生的磨损行为之间的函数关系。在此基础上，将对生产即用齿轮的挤压工艺进行操作优化设计，以确保在整个生命周期内符合与功能相关的公差。在第一个资金期获得的知识构成计划工作的基本基础。在第一个资助期，确定了与工艺有关的控制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由于金属-塑料材料副在运行中的特殊磨损行为而导致的几何偏差的影响。根据得到的数据，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与功能相关的公差的遵守以及配对的寿命。第一阶段的初步调查表明，挤出过程中与应用相关的部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，研究协会为面向过程的公差分配处理了决定性的结果。了解与生产相关的部件特性和操作行为之间的功能相关性，可以更有效地进行产品和工艺设计。此外，面向工艺的齿轮公差优化支持各自需求定义中的设计和测量技术。通过与其他次级项目合作，这有助于降低开发和评估成本，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.