通扎钻削,当钻头横刃穿透工件之后,钻削时的轴向抗力迅速下降,主轴因自重乘势压下而使进给量突然增加,导致扎刀,这时钻头很容易扭断,特别是在钻削大孔径通孔时,这种现象更为严重。因此作必要的预防措施,对降低钻孔生产成本,提高钻孔效率有一定实用意义。下面介绍两种常用的预防措施。 1.改变钻头的几何参数 Through drilling, when the drill chisel penetrates the workpiece, the axial resistance during drilling decreases rapidly. The spindle suddenly increases in feed due to its own weight. As a result, the drill bit is easily broken, This is especially the case when drilling large-diameter through-holes. Therefore, the necessary precautionary measures have some practical significance to reduce the production cost of drilling and improve the drilling efficiency. Here are two commonly used precautions. 1. Change the drill bit geometry