在台钻上直接夹丝维攻丝,不但电机需要正反转,且螺纹深度不易掌握,质量差、生产效率低。尤其对盲孔攻丝,略有不慎就会折断丝锥。而采用附图所示的双速攻丝装置,则能解决上述问题。该装置在攻丝时可慢速进刀,攻到规定深度后,只要提起钻床手柄,丝锥就可快速退出。在批量生产中,特别是对盲孔攻丝,更显示出优越性。 Directly in the drill on the meridional wire tapping wire, not only the motor needs positive and negative, and the thread depth is not easy to grasp, poor quality, low productivity. Especially tapping the blind hole, a slight mistake will be broken tap. The two-speed tapping device shown in the drawings can solve the above problems. The device can be tapping slow feed, tapping the required depth, as long as the lifting of the drill handle, the tap can quickly exit. In mass production, especially for tapping tapping holes, but also shows the superiority.