低刚度薄壁件铣削加工刀具破损及表面质量分析

Damage of Low Stiffness Thin Wall Milling and Analysis of Machined Surface Quality

为分析低刚度薄壁在切削过程中的情况,进行了低刚度薄壁的小径向浸入比切削试验,通过实时监测的方式同步采集薄壁厚度方向的加速度信号和XYZ三个方向的切削力信号,并且通过超景深显微镜对刀具的磨损破损状况及加工表面质量进行观测。试验发现:薄壁刚度较低时,切削振动剧烈,加速度值和X方向的切削力随着进给速度的增大而快速增大;薄壁振动会导致刀具刀刃部分破损现象早于磨损发生,出现多处块状掉落;薄壁顶部因其更弱的刚度导致大量的长条状凸起,严重影响表面质量,且薄壁表面下部加工质量明显优于上部;低刚度时采用逆铣比顺铣更能适当降低切削力并减少毛刺的出现。

In order to analyze the milling conditions of low stiffness thin wall,the cutting tests of low stiffness thin wall are conducted under small immersion ratio condition.Both the acceleration signals in thin-walled thickness direction and cutting force signals are gathered by the way of real-time monitoring.Tool wear,tool breakage and surface quality are observed by microscope.The experimental results show that the vibration of the cutting is very strong when the stiffness of the thin wall is low.At the same time,the acceleration values and the cutting forces in the x-direction rapidly increase with the feed rate.Tool blade breakage occurs earlier than wear because of the vibration,and there are many massive defects.Because of its lower stiffness,the top of the thin wall has a large number of bar-shaped protrusions,which seriously affects the surface quality.And the lower part of the thin-walled surface processing quality is obviously superior to the upper part.Up-milling is better than down-milling at reducing the milling force and burrs.