基于气中放电辅助修整金刚石砂轮的试验研究

提出了一种新型的基于气中放电辅助金刚石砂轮在线修整法,它把气中火花放电修整法和金刚石笔机械修整法有机结合在一起,能实现光学曲线磨床上金刚石砂轮的高效、高精度、低成本和不得使用任何冷却液的在线修整。采用自制的试验装置在MK9025数控光学曲线磨床上对1A1／T2 200×6×32×4 MBD6 120／140 M75型号的砂轮进行了在线修整试验,得出了一些影响金刚笔磨损率的主要因素:火花放电时热源的能量分布状况、金刚石笔修整时的修整深度、进给量以及电源电压。相同工况下机械修整法和气中放电辅助修整法中金刚石笔的磨损率对比试验结果表明:气中放电辅助修整和机械修整有着不同的材料去除机理,它比一般机械修整更有利于提高金刚石砂轮的修整效率和降低金刚石笔的磨损量。磨削YG8硬质合金工件的试验表明,采用气中放电辅助法修整的金刚石砂轮和新的金刚石砂轮有着相近的磨削能力。

EXPERIMENTAL STUDY ON DRY ELECTRICAL DISCHARGE ASSISTED TRUING AND DRESSING OF DIAMOND WHEEL

Through combining electrical discharge thermal effects into the process, dry electrical discharge(dry-ECD) assisted truing and dressing opened a new avenue for reducing the wear rates of diamond dressers. Because the diamond wheel is mounted on the optical projection profile numerical control grinding machine, dielectric liquid is forbidden. The new dry-ECD dressing/truing method basically eliminates the use of dielectric liquid. In order to compare the wear ratios in dry-ECD assisted dressing with those in mechanical dressing, some comparative experiments are done. Experimental results show that the wear ratios of diamond dressers in the dry electrical discharge assisted dressing depend on electrical discharge density distribution, input voltage, depth of cut, and feed rate. Because of the different material removal mechanisms involved in these two truing methods, the wear ratio of diamond dresser in dry-ECD assisted dressing is much higher than that in the conventional mechanical dressing. The experimental results show that dry-ECD assisted truing and dressing diamond wheel has the same grinding capability as the new diamond wheel from the grinding of YG8 hard carbide.