| 摘要 |
<p>A threading control system for tapping with a numerically controlled machine tool, in which threads formed inaccurately due to the vibration in the feeding caused by the feed motor and irregular threaded hole depth caused by the inertia of a spindle rotating system are prevented and the instruction method is simplified. A tap (13) is movably retained in the spindle direction. While the spindle (3) rotates normally, the revolution of the spindle (3) is transmitted to the tap (13) while the amount the tap moving falls within a predetermined range. When the amount the tap moving exceeds the predetermined range, the revolution of the spindle (13) is not transmitted to the tap (13). When the spindle (13) is reversely rotated, a tapper (4) for constantly transmitting the revolution of the spindle (3) to the tap (13) is mounted on the spindle. During threading, the tap is fed initially by the feed motor, but the threading is carried out only with the advancing force of the tap (13) itself turned by the revolution of the spindle (3). The threading sequence is instructed by one block of instruction data.</p> |
