Denso Corporation

Advics Co., Ltd.

Akinori Nakayama

Yasuhiko Yamazaki

Hideaki Shirai

Yasunori Kawamoto

Hidenobu Kajita

Hitoshi Mizutani

Fumiyoshi Ariki

Toshiharu Mizuno

Minoru Watanabe

Shinya Mitani

A gear pump having an inner rotor and an outer rotor is covered by a cylindrical outer casing and side casings. The cylindrical outer casing has two outer circumferential edges which are welded over the entire circumference thereof to the outer edges of the side casings, respectively. The outer casing has two angularly spaced recesses in its inner periphery for receiving slide seals therein. Welding is started at a welding start point which is 90 degrees spaced from the middle point between two recesses. During welding, welding energies are applied to the welding start point and the middle point between two recesses. Those energies tend to deform the casing into oval shapes that are 90 degrees out of phase from each other. Thus, these energies cancel each other, thereby preventing the casing from being deformed.

Welding method and tubular member and gear pump made using the welding method

A cylindrical member is placed in a dead-end hole formed in a housing made of a material such as aluminum. A peripheral portion of the hole is pressed down to plastically deform the housing material and to supply the deformed material into a groove formed on an outer periphery of the cylindrical member. The cylindrical member is calked to the housing in this manner. To supply a proper amount of deformed material into the groove for obtaining a quality calking, an inflection point of a calking curve indicating a relation of a calking force and a calking stroke is detected during the calking process. After the inflection point is detected, the calking is performed by giving a predetermined calking stroke or by adding a predetermined calking force.

Method of calking cylindrical member in hole

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Mie, Japan

Akinori Nakayama