| 摘要 |
<p>A spot welding machine in which a switching operation from one servo gun to another does not require a return to the origin. One of a plurality of servo gun (G1 to G4) is selected and is mounted to a robot (1), and the connector (CN) of the selected servo gun (G1) is connected to a connector (CN10) on the side of a controller (10). Gun shafts are driven by servo motors (M1 to M4) equipped with an absolute pulse coder utilizing a magnetic bubble device. A current to the gun (G1) in use is decided by a movement command to the gun shaft on the basis of an operation program and by a current command generated by a feedback signal obtained from the absolute pulse coder. When the gun (G1) is used after other guns (G2 to G4) are used, the position of the gun shaft of the gun (G1) inclusive of the movement of the gun shafts which are not used is held.</p> |
