| 摘要 |
PURPOSE:To increase start torque, to shorten a start time, and to obtain stable start characteristics, by providing a circuit for releasing an output limit of a torque limiter in a control device, of a motor whose torque is controlled at the time of start. CONSTITUTION:When a feed device is started, a relay 30b becomes off, and to a capacitor 24, charging is executed to positive polarity through an upper limit torque setting device 26. As time passes after start, charging of the capacitor 24 is continued, and voltage of a connecting point 25 increases gradually by plus polarity. At the point of time when a prescribed start time has passed, chrging voltage of the capacitor 24 becomes constant, therefore, after the device has become a regular operating state, the upper limit of output torque of a pushmotor 2 is limited to a value of an extent that buckling of a welding wire does not occur in the conduit. |
