Collet chuck retention span adjusting device of NC automatic lathe and collet chuck retention span adjustment manner null of NC automatic

摘要

PROBLEM TO BE SOLVED: To adjust clamping force by a collect chuck with high accuracy by providing a control means adjusting and setting bar clamping force by the collect chuck to a desired value. ;SOLUTION: A spindle motor is revolved at a low speed. At this time, because an adjusting nut 101 is constrained in the revolution, the nut 101 moves in the right direction. By the moving of this adjusting nut 101 in the right direction, a pawl holder 31 moves in the same direction. By the moving of this pawl holder 31, also a push sleeve 21 and a chuck sleeve 19 move in the same direction, thereby a collect chuck 25 is restricted, a bar 23 is clamped, the clamping force is gradually increased and torque of the spindle motor is gradually increased. When the torque reaches set torque, the spindle motor is stopped.;COPYRIGHT: (C)1999,JPO