Nippon Pillar Packing Co., Ltd.

Shintaro Makihata

Makoto Fujii

Toshihide Iida

Tomoyuki Koike

Tatsuya Fujii

Masaki Miyamoto

Kazukiyo Teshima

A resin tube fitting has a body with a sleeve allowing the longitudinal end of the tube to be put therein, an inner ring with a press-in portion configured to be pressed in the longitudinal end of the tube, and a union nut with a connector configured to be screwed to an outer periphery of the body to allow the longitudinal end of the tube to be put radially between the connector and the press-in portion. The inner ring and the union nut are made of resin, which has a property of contracting in response to change in ambient temperature. The radial contraction rate of the connector is higher by 0.05% or more than that of the press-in portion of the inner ring.

Resin pipe fitting

A resin tube fitting has: a body with an outer sleeve; an inner ring including an insert portion insertable into the outer sleeve to contact the outer sleeve radially, and a press-in portion configured to be pressed into a longitudinal end of the tube; and a union nut configured to be engageable with the body. The body and the inner ring are made of resin, which has a property of contracting in response to change in ambient temperature. A radial contraction rate of the outer sleeve of the body is designed to be higher by 0.09% or more than that of the insert portion of the inner ring.

Resin tube fitting

A structure of a resin-made pipe joint includes a sleeve which is press-insertable from one axial side into one longitudinal end portion of a flexible tube to flare the one longitudinal end portion to hold the flared state, a joint body which is couplable to the sleeve, and a union nut which is fastenable to the joint body to hold a state where the sleeve press-inserted into the one longitudinal end portion is coupled to the joint body. The sleeve has a taper-like first outer circumferential surface, a second outer circumferential surface having an outer diameter that is smaller than a maximum outer diameter of the first outer circumferential surface, and an annular step portion which is an annular step portion that is disposed between the first outer circumferential surface and the second outer circumferential surface and comprises an edge portion on a side of the first outer circumferential surface.

Structure of resin-made pipe joint

A structure of a resin-made pipe joint includes a joint body having a cylindrical shape, a sleeve having a cylindrical press-inserting portion which is press-insertable into the joint body and a cylindrical coupling portion which is press-insertable into a tube, and a fastening member for fixing the tube which is in a state where the coupling portion is press-inserted, to the joint body through the sleeve. The sleeve contains a sealing surface in an outer circumferential surface of the press-inserting portion, the sealing surface being closely contactable with an inner circumferential surface of the joint body, and comprises a non-contacting surface between the press-inserting portion and the coupling portion, the non-contacting surface forming a space with respect to the inner circumferential surface of the joint body, when the sealing surface is closely contacted with the inner circumferential surface of the joint body.

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Osaka, Japan

Shintaro Makihata