Development of a Holistic Approach for Increasing Bore Quality at High-Speed-Reaming under Special Consideration of Low-Frequency Pendulum- Oscillations

研究项目的目的是通过减少低频横向振荡来提高多刀具扩孔过程中的孔质量。因此，研究对象是直径为10 mm，悬臂长度为4 × d的硬质合金多刃铰刀。切割刃的数量和俯仰角将在项目的进展过程中定义，作为过程模拟的结果。目前最先进的工具有六个切削刃和一个小的3-5°的非对称俯仰角，用于这些工具直径的区域。为了找出引起横向振动的原因，将采用动态仿真模型（多体模型）。除了平稳过程阶段外，该模型还将考虑非平稳阶段，即切削刃开始穿透材料时，这与振荡的开始有关。第二步，开发的多体模型能够简单而经济地改变扩孔工具的相关几何参数及其对镗孔质量的影响。因此，所采用的方法追求的目标是减少主切削刃的载荷集合体，以及扩展次切削刃的导向功能。通过这种措施，周围工件的切削刃的渗透将被最小化。除了满足所需的圆度公差（和圆柱度）外，为了降低制造成本，与极不均匀的分段铰刀相比，开发的刀具必须具有更高的刀具寿命。因此，在工程中应调查哪些干扰和因果关系导致低频横向振荡，以及必须对主切削刃和次级切削刃进行哪些几何变化以减少低频横向振荡。此外，必须确定扩孔工具的进一步修改，以可靠地达到所需的工具寿命。

Aim of the research project is to increase the bore quality at reaming processes with multi cutter tools by reducing low frequency lateral oscillations. Therefor object of investigation are multi blade reamers made of carbide with a diameter of 10 mm and a cantilever length of 4xd.The number of cutting edges as well as the pitch angle will be defined during the progress of the project as a result of the process simulation. State of the art are tools with six cutting edges and a small non symmetric pitching of 3-5° for those area of tool diameters. To figure out the reason of the cause of lateral oscillations a dynamic simulation model (multi-body-model) will be implemented. Besides the stationary process phase the model will also consider the non stationary phase when the cutting edges start penetrating into the material which is relevant for the beginning of the oscillations. In a second step the developed multi-body- model enables to a simple and cost effective variation of relevant geometric parameters of the reaming tool and their impact on the bore quality. The therefore used methods pursue the objective to reduce the load collective on the main cutting edge as well as the extension of the guiding function of the secondary cutting edges. By this measures the penetration of the cutting edges of the surrounding workpiece will be minimized. To deliver also a contribution to the reduction of the manufacturing costs besides the fulfillment of the required circularity tolerances (and cylindricity) the developed tool has to have a higher tool life compared to the extremely uneven segmented reamers. Therefor within the project should be investigated which disturbances and cause-effect relationships lead to low frequency lateral oscillations and which geometric changes of main and secondary cutting edges have to be done to reduce them. Additionally further modifications of the reaming tool have to be identified which are necessary to reliably achieve the required tool life.