On the Development of Curved-Shape End Mill for Suppressing Machining Vibration in the Mold Machining Process with Cutting Simulation

本研究发展了一种分析，以预测切削力和刀具位移，并显示了刀具几何形状的设计，以抑制刀具振动加工曲线形状的立铣刀。基于剪切面模型的切削力分析方法可以利用正交切削试验数据计算切削力。所提出的分析方法可以通过插入式球头立铣刀和粗加工立铣刀的铣削加工实例得到验证。然后，可以开发一种分析来预测刀具位移与切削力。在切削过程中，测量了切削刃旋转过程中的动态特性，求解了振动方程。结果表明，动态特性随刀具旋转而变化。分析结果表明，下切加工的加工表面质量优于上切加工，并进一步研究了刀具几何形状对切削力的影响。分析和实验结果表明，减小切屑接触长度的球头立铣刀可以降低切削力。研究了刀具减屑接触长度铣削过程中的刀具位移分析。研究结果表明，切屑接触长度的减小对刀具振动的抑制和切削力的降低有很大的作用，本研究可为刀具行业减少开发新刀具几何形状的时间，为模具加工行业预测工艺故障提供操作规划。

This study develops an analysis to predict cutting force and tool displacement and shows a design of tool geometry to suppress tool vibration in the machining with curved-shape end mill. The analysis based shear plane model can calculates cutting force with orthogonal cutting date, which can be obtained in a few cutting tests. The developed analysis can be verified in the examples of milling process with insert-type ball end mill and roughing end mill. Then an analysis can be developed to predict tool displacement with cutting force. Dynamic characteristics in cutting process during rotating cutting edge are measured to solve vibration equation in analysis. It is shown that dynamic characteristics change with cutter rotation. The analysis based on the characteristics shows the machined surface in down-cut process is better than that of up-cut process.The effect of tool geometry on cutting force is investigated with the developed analysis. It is proved that ball end mill having chip reduced contact length can reduce cutting force in the analysis and experimental results. Tool displacement analysis is examined in the milling process with tool having chip reduced contact length. It is proved that chip reduce contact length has a large effect to suppress tool vibration with reducing cutting force.This study can contribute to reducing the term for developing new tool geometries in the cutting tool industry ; and to operation planning with predicting process troubles in mold machining industry.