在加工细长的孔,直径和长度的比例 L/D=20～30时,清除切屑和冷却钻头是很困难的。用普通的麻花钻头来加工这种孔时,要经常将钻头退出,以清除切屑和冷却钻头。这样就增加了辅助时间,因而降低了生产效率,同时还容易出废品。苏联工人柴霍洛夫采用了截短的钻头来加工深孔,获得良好的效果。附图就是这种加工方法。在图中可以看到,工件1是安装在 V In the processing of elongated holes, the ratio of diameter to length L / D = 20 ~ 30, the removal of chips and cooling the drill bit is very difficult. When machining this hole with an ordinary twist drill, the drill is often removed to remove chips and cool the drill bit. This increases the auxiliary time, thus reducing the production efficiency, but also easy to waste. The Soviet worker Chai Halofu used a truncated drill to machine deep holes for good results. The figure is this method of processing. It can be seen in the figure that the workpiece 1 is mounted on the V