Super-abrasive Grinding Wheel with Helical Gooves

在常规氧化铝砂轮上进行螺旋槽雕刻，在减小磨削力、消除磨削烧蚀等磨削性能方面具有良好的效果。本研究的目的是将这种螺旋槽应用于价格昂贵但磨削性能高的超磨具上。结果表明：对于树脂结合体cBN砂轮，由于树脂结合体的持粒性差，砂轮表面粗糙度明显降低，砂轮磨损加剧；然而，对于无孔结合剂的砂轮，如树脂或金属，螺旋槽对提高冷却剂对磨削点的渗透作用是显著的，仅0.3mm深的槽就提供了足够的冷却剂来消除磨削热，防止磨削烧伤。镀层结合cBN砂轮上形成的螺旋槽减少了接触弧区与工件啮合的切削刃数量。因此，当磨损平面面积增大时，螺旋槽缓解了磨削力的快速增加，从而使砂轮提升，有效地利用了昂贵的超磨料。并尝试了几种经济的方法在超磨料砂轮表面刻出螺旋槽。对于镀胶轮毂，采用掩模法在轮毂表面可以很容易地形成沟槽。对树脂粘接轮毂进行了试制，在轮毂表面粘接薄条模制颗粒层的铝盘，证明其具有良好的磨削性能和足够的湿态耐久性。

Helical grooves enqraves a conbentional alumina wheel proves to show favorable effects on the improvement of grinding performance such as decteasing of grinding forces and elimination of grinding burn. This research is to apply such helical grooves to super-abrasive wheels which are very expensive but have high grinding performance.Obtained results are as follows:For resin-bonded cBN wheel, hilical grooves decrease the grinding forces remarkably while the roushness of grouns surface ands wheel wear deteriorate due to poor grain holding of resin-bound. However, for wheels with pore-less bond such as resion or metal, the effect of helical grooves to improve the coolant penetration to the grinding point is notable and only 0.3mm deep grooves provide sufficient coolant to remove grinding heat and prevent grinding burn.Helical grooves formed on plating-bonded cBN wheel dectrase the number ofd grain cutting edges which are engaging with workpiece in contact arc area. Therefore, when the wear flat area inctrases, helical grooves relieve the rapid increasing of grinding forces and consequently the wheel lifr and utilize expensive super-abrasives efficiently.Several economical methods to engrave hilical grooves on super-abrasive wheel face are also attempted. For plating-bonded wheel, grooves can be formed witout difficulty using masking method on the wheel face. For resin-bonded wheel, a aluminum disc with thin molded strips of grain layer glued on a wheel face is produced as a trial and it proved to have good grinding performance and sufficient durability in wet condition.