Toyota Jidosha Kabushiki Kaisha

Kawasaki Jukogyo Kabushiki Kaisha

Toyota Jidosha Kabushiki

Yoshitaka Sakamoto

Kazutsugu Suita

Seiji Suzuki

Hitoshi Arasuna

Satoru Hirayama

A spot welding apparatus having a pressing axis to which a mechanical impedance control device is provided. The mechanical impedance control device includes a welding condition instruction device, a pressing axis control device, and a mechanical impedance calculation device. A method for controlling the spot welding apparatus, wherein for welding relatively thin plates, the mechanical impedance is controlled to be low, and for welding relatively thick plates, the mechanical impedance is controlled to be high.

Spot welding apparatus and a method for controlling the apparatus

An integrated control system for a work robot may be used for controlling multiple work robots as well as multiple work tools connected to the work robots. The integrated control system includes a robot control central processing unit (CPU), at least one work control CPU, a shared memory, and a system bus constructed to transmit information between each of the CPUs and the shared memory. The robot control CPU, the work control CPU, and the shared memory are connected to the system bus.

Integrated control system for a work robot

A welding gun includes an actuator and welding tips. The actuator includes a stator coupled to a welding robot and a rotor rotatable relative to the stator about an axis of the actuator. The stator includes an axially extending portion and at least one circumferentially extending arm. The rotor includes an axially extending portion and at least one circumferentially extending arm. The welding tips are coupled to an end of the circumferentially extending arm of the stator and an end of the circumferentially extending arm of the rotor. Lengths of the axially extending portion of the stator and the axially extending portion of the rotor can be determined to any length so long as strength and rigidity are assured.

Welding gun

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.

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Nagoya, Japan

Yoshitaka Sakamoto