Honda Giken Kogyo Kabushiki Kaisha

Toshihiro Murakawa

Gen Tsujii

Nobuo Kobayashi

Makoto Suzuki

Mitsuo Kuwabara

Fumitomo Takano

Yukihiro Yaguchi

Toshiaki Nagasawa

Isao Bundou

Kenji Kusumegi

Kouji Oda

When a workpiece which is made up by laminating a plurality of plates of different thicknesses is welded by using a spot welding gun having a pair of electrode tips, the electrode force to the workpiece by one of the electrode tips, which is positioned on the side of a thinner plate, is made larger that the electrode force to the workpiece by the other of the electrode tips. The contact pressure on the side of the thinner plate becomes larger with the result that the contact resistance decreases. Therefore, the nugget on the side of the thinner plate becomes smaller than the nugget on the side of the thicker plate.

Electric resistance welding method with unequal force application

A device for confirming an open state of a welding gun having a reciprocating mechanism or moving a movable electrode into and out of contact with a workpiece has a pin feeler mounted on an end of a cylinder of the reciprocating mechanism and movable into and out of contact with a piston movably disposed in the cylinder. The device also has a helical compression spring for resiliently biasing the pin feeler, a housing accommodating the biasing means, and a proximity switch fixedly mounted in the housing. When the piston moves in a direction to open the welding gun, the piston presses and moves the pin feeler until an end of the pin feeler is detected by the proximity switch to confirm the open state of the welding gun. The open state of the welding gun can be detected without being adversely affected by dust and dirt particles, grease, and a mist in the cylinder. The device can be assembled highly efficiently.

Device for confirming opening of welding gun

An arm main body of a welding gun is formed of an aluminum alloy. An anodic oxide coating is formed on an entire surface of the arm main body. The arm main body is then machined to remove the anodic oxide coating formed on a power feeing terminal portion and an electrode tip connecting portion which are provided in the arm main body. The anodic oxide coating may be subjected to a sealing treatment with a dispersion liquid in which a magnetic material is mixed in dispersion. Alternatively, the arm main body formed of an aluminum alloy may be subjected to an anodic oxide coating treatment with a treatment liquid in which a magnetic material is mixed in dispersion.

Welding gun arm and method of manufacturing same

A resistance welding apparatus mounted on a robot arm includes a transformer having primary and secondary windings. Two gun arms supporting respective welding electrodes in confronting relation to each other are relatively movable toward and away from each other. Conductors extending from the secondary winding are electrically connected to one of the welding electrodes through one of the gun arms, and the transformer is supported on said one gun arm. Rectifiers are used which have terminals engaging said one gun arm and opposite terminals engaging the conductors. The rectifiers and the conductors are securely joined to the one gun arm.

Resistance welding apparatus with gun-arm mounted transformer

A transformer apparatus for use with a welding gun includes four transformer/rectifier assemblies each including a transformer having a secondary winding and a rectifier, a terminal plate connected to the secondary winding through the rectifier, and a center tap terminal plate connected to an intermediate portion of the secondary winding. The terminal plate and the center tap terminal plate are disposed on one side of the transformer, and the transformers of the transformer/rectifier assemblies are disposed side by side. The terminal plates of the transformer/rectifier assemblies are disposed closely to each other in confronting relation. First and second conductive bodies interconnect the terminal plates and the center tap terminal plates of the transformer/rectifier assemblies. The transformer/rectifier assemblies are symmetrically disposed.

Growing community of inventors

Sayama, Japan

Toshihiro Murakawa