The working principle of a drilling and tapping machine is based on three mechanisms: sequential linkage, torque coordination, and controllable stroke. First, in the drilling stage, the spindle drives the drill bit to rotate at high speed and feed axially along a set feed rate. Material is removed by the cutting action of the drill bit's cutting edge, forming a cylindrical through hole or blind hole. When the drilling depth reaches the preset value, the control system automatically triggers a tool change or mode switching action-some models use a dual-spindle structure, with the drilling spindle and tapping spindle operating independently; more common models use an internal clutch mechanism or servo reversing device to switch the spindle from a high-speed, low-torque state to a low-speed, high-torque state, simultaneously changing or switching to the tap.
In the tapping stage, the spindle rotates and moves axially synchronously at a speed precisely matched to the pitch and feed rate, causing the tap to cut a standard internal thread along a helical trajectory within the drilled hole.
Throughout the process, the spindle rotation angle, feed displacement, and torque feedback are strictly coupled to ensure complete thread profile, accurate pitch, and a smooth surface.
