电火花机械磨削修整粗粒度成形砂轮试验研究

Experimental Research of Coarse-grained Forming Grinding Wheel Dressed by EDDG

粗粒度金属基金刚石砂轮磨削效率高,面形精度保持性好,可以满足各种成形零件的精密加工,但存在因修整困难而难以推广的问题。针对该问题,提出采用电火花机械磨削法修整粗粒度金刚石砂轮。探究了放电参数对修整效率及刀具损耗量的影响规律,并以修整效率为优化目标选取粗修整试验放电参数,以修整精度为优化目标选取精修整试验放电参数。设计了半径为3 mm的凹圆弧、凸圆弧砂轮修整试验,粗修整后凹圆弧、凸圆弧半径分别为2867.510μm、2919.254μm,尺寸误差分别为4.43%、2.69%,轮廓精度PV值为54.34μm;精修整后凹圆弧、凸圆弧半径分别为3005.107μm、3001.588μm,尺寸误差分别为0.17%、0.053%,轮廓精度PV值为17.28μm。最后,磨削碳化硅陶瓷试件,获得凹圆弧、凸圆弧半径的尺寸误差分别为0.24%、0.045%,工件表面粗糙度Ra可达0.463μm。

The coarse-grained metal bond diamond wheel had high grinding efficiency and good surface shape accuracy retention,which might meet the precision machining of various forming parts,but the difficulty of dressing maked it difficult to popularize.In order to solve this problem,the EDDG was proposed for coarse-grained diamond grinding wheel dressing.The influences of discharge parameters on dressing efficiency and tool loss were investigated.The discharge parameters of rough dressing were selected with the dressing efficiency as the optimization objective,and the discharge parameters of precision dressing were selected with the dressing accuracy as the optimization objective.The concave and convex arc-shaped wheels with design radius of 3 mm were used for dressing experiments.After rough dressing,the radius of concave and convex arc-shaped are as 2867.510 μm and 2919.254 μm respectively,the dimensional errors are as 4.43% and 2.69% respectively,and the PV value of profile accuracy is as 54.34 μm.After precision dressing,the radius of concave and convex arc-shaped are as 3005.107 μm and 3001.588 μm respectively,the dimensional errors are as 0.17% and 0.053% respectively,and the PV value of profile accuracy is as 17.28 μm.Finally,the dimensional errors of concave and convex arc-shaped obtained by grinding silicon carbide ceramic specimens are as 0.24% and 0.045% respectively,and the surface roughness value of the workpiece is as 0.463 μm.