大直径无心磨金刚石砂轮制作及修整工艺研究

Study on the manufacturing and dressing of large diameter diamond wheel for centreless grinding

大直径无心磨砂轮(一般指直径D≥500mm,厚度H≥150mm)制造工艺一直是难点,具体表现在制造过程成品率低,性能难以满足要求。本文对大直径无心磨金刚石砂轮的制造工艺进行分析和讨论,提出一套完整可行制造工艺,具体包括:通过采用梯度粒度提高粗糙度,改进工艺配方提高自锐性,对实际制造过程中注意问题进行较全面分析以提高制造成品率,并对大直径无心磨金刚石砂轮热压机常用工艺热压参数热压级功率、吨位、加热板面积等进行讨论,得出合理热压工艺参数;最后,对修整工艺进行研究,大直径无心磨金刚石砂轮对修整要求精度高而且操作困难,笔者在T8365型制动鼓镗床设计全新修整工艺,实际应用证明修整工艺可操作性强,修整精度高。

The manufacture of large diameter diamond griding wheel （ D≥500mm, H≥150mm） for centreless grinding is a bottle - neck because of the high reject rate. This paper presented a new and feasible manufacturing technique of such wheel. Gradient grit sized diamonds are used （ 100/120,120/140,140/170,170/200 from outer towards centre）to improve the grinding roughness. An optimized fomular with pore ratio not less than 3%, copper powder content 〈 12% and 5 - 8% SiC as filler, to improre the self - sharpening ability of the wheel. Parameters of the sintering technique are also. optimized. A heat - preservation duration of 7 - 9 hours is suggested. Finally, an interesting dressing technique is put forward.