| 摘要 |
PURPOSE:To prevent final torque of each shaft from dispersion and make it coincide with a desired value by providing fitting-up torque to each shaft which is fastened simultaneously to a desired fastening torque after the fitting-up torque is reached. CONSTITUTION:In a double shaft screw fastener, when shaft torque of one driver bit 12a reaches fitting-up torque set by a first torque setting means 20a earlier than the other driver bit 12b, a drive motor 13a for the driver bit 12a is stopped. Thereafter, when the shaft torque of the other driver bit 12b reaches the fitting- up torque, a signal of fitting-up completion is generated to drive the motor 13a again. Thus, since the respective driver bits 12a, 12b start the fastening as soon as the fitting-up of all shafts is completed, they reach a desired fastening torque set by second torque setting means 21a, 21b approximately at the same time and motors 13a, 13b for the respective shafts are stopped by the signals of completed fastening generated from second comarators 19a, 19b. |
