Kawasaki Jukogyo Kabushiki Kaisha

Toyota Jidosha Kabushiki Kaisha

Toyota Jidosha Kabushiki

Satoru Hirayama

Kazutsugu Suita

Seiji Suzuki

Yoshitaka Sakamoto

Hitoshi Arasuna

The spot welding electrodes are driven by the servomotor (30) so as to be moved to and pressured against a work surface. The welding pressure controller (27) detects welding pressure corresponding to current flowing through the servomotor (30) via a driver (26) and controls the welding pressure so as to be changed according to the set welding pressure condition. The welding current flowing through the spot welding electrodes is controlled by the welding current controller (28). The welding current controller (28) and the welding pressure controller (27) are both controlled synchronously by the robot CPU (20) via the system bus (21). The robot CPU (20) controls the welding pressure and the welding current on the basis of the welding condition data (22) stored in a memory, so as to be changed in synchronism with each other at a plurality of welding stages, respectively. By doing this, it is possible to control the welding pressure and the welding current during the spot welding synchronously and systematically, thus realizing a spot welding control adaptive to work behavior.

Spot welding control method and apparatus

Positions where the pair of electrode chips are in contact with each other are regarded as reference positions. Desired starting positions where the tips of the pair of electrodes are slightly apart from the surfaces of a workpiece are determined on the basis of the reference positions X taking into consideration the thickness d of the workpiece. The electrode chips are moved to the desired starting position. The electrode chips are moved at a predetermined low speed until contact positions where the electrode chips come into contact with the workpiece (20). The electrode chips are then moved at a predetermined speed from the contact positions to overshot positions where the workpiece is compressed between the electrode chips.

Welding gun control method

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Kobe, Japan

Satoru Hirayama