基于刀具磨损映射关系的微细铣削力理论建模与试验研究

Theoretical Modeling and Experimental Study of Micro Milling Force Based on Tool Wear Mapping

微细铣削加工过程中,刀具直径小且磨损较快,刀具磨损对微细铣削力有着明显的非线性影响,同时刀具跳动又对刀具每齿的磨损表现出不同的影响效应,这些影响因素会导致加工过程的不稳定性和精度。然而,目前缺乏考虑具有刀具跳动和磨损效应的通用微细铣削力模型,研究了刀具跳动与刀具每齿磨损量之间的变化规律,提出了一种同时包括刀具跳动和刀具磨损效应的新型的微细铣削力模型。该模型中,根据刀具每齿磨损量与切削位置的几何关系,改进了瞬时切削厚度模型,基于不同切削刃所对应的受力情况,同时将刀具直径方向上磨损变化量与力模型系数相关联,从而来提高力模型的精确度。最后,通过不同铣削参数下的铣削试验,论证了所提出模型的准确性和有效性。利用所提出的模型,可以通过监测铣削力的大小来辨别刀具尺寸是否在可持续铣削的范围内,从而提高微铣削的加工精度和效率。

In the process of micro milling, the tool diameter is small and the wear is fast. The tool wear has obvious nonlinear effect on the micro milling force, and the tool run-out has different effects on the wear of per tooth. These factors will lead to the instability and precision of machining process. However, the general micro milling force model considering tool runout and wear effect has not been established, Therefore, the relationship between tool run-out and tool wear per tooth is studied, and a new micro milling force model including tool run-out and tool wear effects is proposed. In this model, the tool run-out and tool wear per tooth are considered in the instantaneous cutting thickness model. According to the force conditions of different cutting edges, the wear variation along the tool diameter direction is associated with the force model coefficient to improve the accuracy of the force model. Finally, through the milling experiments under different milling parameters, the accuracy and effectiveness of the proposed model are demonstrated. The proposed model can be used to detect whether the tool size is within the range of sustainable milling by monitoring the milling force to ensure accuracy and efficiency of micro milling.