Nitto Kohki Co., Ltd.

Haruo Kubo

Noboru Saito

Hirosato Takeuchi

Naoyuki Kotake

Makoto Nagumo

Yutaka Tanaka

Osahiko Miyazaki

Shigeru Yasuda

Method and tool for forming a tapered hole in a cylindrical work by

A fluid pipe coupling comprises a plug and a socket, at least one of which includes a cylindrical body member having an end portion adapted to engage the other and a caulking end portion, and an adapter member having a connector end portion adapted to be connected with a pipe member and a caulking end portion. One of the caulking end portions has a cylindrical caulking portion, while the other has a cylindrical caulking receiving portion adapted to engage the caulking portion. The caulking receiving portion has a plurality of annular grooves and annular projections therebetween on the peripheral surface thereof. The caulking portion and the caulking receiving portion engage each other with a seal member interposed therebetween. These two portions are caulked so that the cylindrical body member and the adapter member are coupled integrally with each other.

Fluid pipe coupling

A forging method comprises the following four steps: a first step of disposing a columnar material into a first die and extruding one end portion of the material with a first punch in a direction opposite to the advancing direction of the first punch, a second step of deepending a first blind hole in a second stepped die with a cavity having large and small internal diameter portions, and extruding the other end portion of the material into the inside of the small internal diameter portion of the cavity with a second punch which has been previously extended thereinto, a third step of fitting the first and second blind holes to third punches while exposing the small outer diameter portion from a third die and pressurizing, by means of a sleeve, only an end face portion of the small outer diameter portion formed with the second blind hole to expand the small outer diameter portion of the material toward an outer periphery, and a fourth step of punching out a blind portion of the material.

Forging method for a hollow article

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Tokyo, Japan

Haruo Kubo