Numerical multiscale modelling and optimization of cooling concepts in gear skiving

齿轮车削冷却概念的数值多尺度建模和优化

• 批准号: 439954775
• 负责人: Professor Dr.-Ing. Hans-Jörg Bauer
• 金额: --
• 依托单位: Fraunhofer-Institut für Werkstoffmechanik (IWM)
• 依托单位国家: 德国
• 项目类别: Priority Programmes
• 资助国家: 德国
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/439954775?language=en
• 关键词: Numerical; multiscale; modelling; optimization; cooling

The project aims in modelling the lubrication and cooling with resulting chip formation in power skiving, a kinematically complex and inaccessible machining process for gears. The cutting conditions vary along the cutting edge and during the process. The resulting multi-part chips repeatedly disrupt the process by adhesion to workpiece or tool surfaces or they get caught between workpiece and clearance face. This results in effects like squeezed chips, which lead to surface defects and tool wear. Only a model of the chip formation under the influence of the cooling lubricant enables understanding the occurrence of these defects. Dominant factors for chip formation are process parameters and the cooling lubricants effect between chip and rake face. In practice, the optimisation of the lubricants application is experience-based. A model-based process optimization requires considering the lubricants application and distribution, as well as the influences on the friction between chip and rake face and of course the effects on chip formation and chip flow. However, the entire process is too complex to be reproduced in a single model. Therefore, a simulation is to be created in which a flow model is coupled with a chip formation model and a friction model. The aim of the second funding phase is to transfer the developed coupled simulation methods of the orthogonal bonded cut to the complex power skiving process using compressed air and oil flood cooling. The complex mechanisms that lead to squeezed chips are considered on a multiscale level in the sub-areas of tribology, chip formation and fluid flow. Chip formation is modelled by means of an FEM simulation. The cooling lubrication concept is modelled using the VOF and SPH methods and the friction between tool and workpiece is investigated with molecular dynamic and quantum chemical simulations taking into account the cooling lubricant, which affects chip formation and adhesion to the tool. The first step is the transfer of the simulation models of the individual sub-areas to the skiving process and subsequently their coupling for a holistic view of the process and the complex interactions of the considered scale areas. This simulative mapping of the influence of the effect of the differently considered cooling lubrication strategies lays the foundation for describing the main effect mechanisms that lead to chip squeezes. In the third phase of the project, based on the generated understanding of the development of chip squeezes, suitable cooling lubrication strategies are to be developed with reference to the main mechanisms of the investigated scales and can be used in the future for the setting of a stable, advantageous chip formation and thus to better surfaces and longer tool life.

该项目的目标是对齿轮的润滑和冷却进行建模，并在动力滑移过程中形成切屑，这是一种复杂的齿轮加工过程。在加工过程中，切削条件会随切削刃的变化而变化。由此产生的多部件切屑通过粘着到工件或刀具表面或卡在工件和间隙表面之间而反复扰乱加工过程。这会导致像挤压切屑这样的效果，从而导致表面缺陷和刀具磨损。只有冷却润滑剂影响下的切屑形成模型才能理解这些缺陷的发生。影响切屑形成的主要因素是工艺参数和切屑与前刀面之间的冷却润滑剂作用。在实践中，润滑油应用的优化是基于经验的。基于模型的工艺优化需要考虑润滑剂的应用和分布，以及对切屑与前刀面之间摩擦的影响，当然也包括对切屑形成和切屑流动的影响。然而，整个过程过于复杂，无法在单一模型中重现。因此，将创建流动模型与切屑形成模型和摩擦模型耦合的模拟。第二个资金阶段的目标是将开发的正交粘结切割耦合模拟方法转移到使用压缩空气和注油冷却的复杂节电过程。导致挤压切屑的复杂机制在摩擦学、切屑形成和流体流动等子领域中进行了多尺度的研究。切屑的形成是通过有限元模拟的方式进行的。利用VOF和SPH方法模拟了冷却润滑的概念，并考虑了冷却润滑剂对切屑形成和与刀具的粘附性的影响，用分子动力学和量子化学模拟方法研究了刀具与工件之间的摩擦。第一步是将各个分区的模拟模型转移到跳跃过程，然后将它们耦合起来，以便对该过程和所考虑的规模区域的复杂相互作用有一个整体的看法。这种对不同冷却润滑策略效果影响的模拟映射为描述导致切屑挤压的主要作用机制奠定了基础。在项目的第三阶段，基于对切屑挤压发展的理解，将参照所研究的鳞片的主要机制来开发合适的冷却润滑策略，并可在将来用于设置稳定、有利的切屑形成，从而获得更好的表面和更长的刀具寿命。