| 摘要 |
PURPOSE:To maintain specified tension on a strand and to produce a spring having a specified coil diameter by moving a detaining body toward a mandrel to wind the strand on the mandrel and controlling the moving speed of the detaining body. CONSTITUTION:A mandrel 1 is rotated by the 1st motor 3, and a moving body 6 is moved by the 2nd motor 11 at the moving speed corresponding to the pitch of a coil spring. A detaining body 21 is moved toward the direction of a mandrel 1 by the 3rd motor 20. When the tension on a strand (a) increases, the torque of a driving shaft 2 increases and therefore the rotating speed of the 3rd motor 20 is increased by the signal from a contol circuit 24 for driving motor, by which the motor 21 is moved fast and the tension of the strand (a) is decreased. When the tension on the strand (a) decreases conversely, the rotating speed of the motor 20 is decreased and the moving speed of the body 21 is decreased, by which the tension on the strand (a) is increased to maintain the specified tension on the strand (a). The terminal end of the strand (a) is disengaged from the body 21 upon arriving of the body 6 at the position facing the coiling end of the mandrel l, then a pressing roller 5 descends and the strand (a) is grasped by the mandrel 1 and the roller 5 and a coil spring is thus formed. |
