| 摘要 |
PURPOSE:To determined the satisfactory condition of screw-fastening and to ensure the high quality of a fastened article, by providing such an arrangement that the feed of drive pulse to a pulse motor is interrupted, simultaneously with the issuance of a signal indicating the completion of final fastening when shaft torque reaches a predetermined final fastening torque. CONSTITUTION:A screw-fastening machine body 5 comprises a pulse motor 10, a driver bit 11 and a transfer shaft 12 for transmitting rotational power from a rotary drive source 10 to the driver bit 11. The shaft 12 is provided with a torque sensor 13 for detecting the shaft torque of the driver bit 11. The body 5 is arranged to be able to be vertically moved by a lift cylinder 14 which also vertically moves a catcher 7 through a rod link 4. A comparator 28 issues a signal indicating the completion of final fastening when the detected torque value of the torque sensor 13 reaches a set value 25 corresponding to the final fastening torque, and therefore the rotation of the motor 10 comes to a stop. Simultaneously, timers Tc, Ti are reset so that they initiate time counts, and the satisfactory condition of fastening is determined. |
