我厂在加工 S195型柴油机气缸体缸盖面上的M16×1.5螺孔的底孔时,原先采用大钻头改制成复合钻,使底孔和孔口倒角一次加工成形。由于自制复合钻时,导向部分和切削部分的同轴度难以保证,钻头导向支撑点与工件的距离过长,加工后底孔的位置度很差,影响到攻丝后螺孔的质量;并且孔口的倒角也无法单独调整,使用上又不经济。 I plant processing S195 diesel engine cylinder head cylinder head M16 × 1.5 hole bottom hole, the original large drill into a complex drill, so that the bottom hole and the hole chamfering a forming process. Due to the self-made composite drill, the concentricity of the guide portion and the cutting portion is difficult to guarantee, the distance between the drill support point and the workpiece is too long, the position of the bottom hole after processing is poor, which affects the quality of the tap hole after tapping; The chamfer of the orifice can not be adjusted separately, it is uneconomical to use.