铣削成形参数对冷冻砂型铣削力的影响

Influence of Milling Forming Parameters on the Milling Force of Frozen Sand Mold

冷冻砂型是以型砂和水基黏结剂为造型材料的绿色铸造工艺,基于减材原理的数字化铣削成形技术可以实现冷冻砂型的高精高效加工。以70/140目烘干硅砂混合5%(质量分数)水制备的冷冻砂型为研究对象,在-25~-20℃的成形温度区间内,依托数字化无模铸造精密成形机探究铣削参数对冷冻砂型铣削力的影响。对9253B切削力计测量的铣削力信号采用快速傅里叶变换(FFT)进行处理与分析,通过控制变量法揭示各铣削成形参数对冷冻砂型铣削力的影响机理。结果表明,铣削力信号由单一信号组成,铣削力信号的周期与主轴转速周期成正比,铣削力信号的幅值随着进给速度、铣削宽度和铣削深度的增大而增大。

Frozen sand mold is a green casting process with molding sand and water-based binder as molding material.Digital milling forming technology based on the principle of material reduction can realize high-precision and efficient processing of frozen sand molds.The frozen sand mold prepared by 70/140 mesh dried silica sand mixed with 5%(mass fraction)water was taken as the research object.In the forming temperature range of-25 to-20℃,the influence of milling parameters on the milling force of the frozen sand mold was investigated by digital precision forming machine without pattern casting.The milling force signal measured by the 9253B cutting force meter was processed and analysed by fast Fourier transform(FFT).The influence mechanism of each milling forming parameter on the milling force of the frozen sand mold was revealed by the control variable method.The results show that the milling force signal is composed of a single signal.The period of the milling force signal is proportional to the period of the spindle speed.The amplitude of the milling force signal increases with increasing feed rate,milling width and milling depth.