聚氨酯摩擦盘的磨削加工研究

Study on grinding process of PU friction disc

聚氨酯橡胶是一种难切削加工非金属材料,材料软、弹性大且导热性较差,因此很难加工到要求的形状精度、尺寸精度及表面粗糙度。针对聚氨酯橡胶的这种加工性能,提出了聚氨酯摩擦盘的磨削加工工艺:先用成型法进行粗磨,再用成型法进行精磨和抛光。粗磨选用30#粒度的黑色碳化硅大气孔陶瓷结合剂砂轮,N级硬度,切削用量0.01mm,用电镀金刚石滚轮修整砂轮圆弧,成型磨削,可以保证聚氨酯摩擦盘的形状和位置精度(R=3.5-+00..1058,S/2=3±0.05mm);精磨选用具有抛光作用的120#白刚玉PVA砂轮,用电镀金刚石滚轮修整砂轮圆弧,精磨和抛光同时完成,可以保证聚氨酯摩擦盘的尺寸精度(ΦA=50±0.03mm)和表面粗糙度(Ra=0.4μm)。

Polyurethane（PU） rubber is difficult to be fabricated into the required precision in form, dimension and surface roughness for it is soft, high in elasticity and bad in thermal conductance. According to PU＇ s characteristics above, the grinding process of the PU friction disc was presented. The disk was first roughly ground and then precisely ground and polished by profile grinding. A black SiC grinding wheel with 30# grit size, large pores and N scale hardness was used in rough grinding, the cutting feed of which is 0.01mm. The arc of the grinding wheel was finished using an electroplated diamond roller. The profile grinding may ensure that the form and position precision of the disc be R = 3.5 ＋0.15 -0.08 and S/2 = 3 0.05mm. Using a 120# white corundum PVA grinding wheel for precision grinding, and an electroplated diamond roller for arc finishing, the disc can be pre- cisely ground and polished at the same time, the size and surface roughness of the disc can reach ФA = 50±0.03mm and Ra =0.4μm respectively.