Pipe connecting device

Patent metadata

Field	Value
Publication number	US-10132431-B2
Application number	US-201414888140-A
Country	US
Kind code	B2
Filing date	Mar 24, 2014
Priority date	May 8, 2013
Publication date	Nov 20, 2018
Grant date	Nov 20, 2018

Abstract

A pipe-connecting device includes: an inner ring having: an outer circumferential portion having a tip-contracted outer-circumferential flared surface that is to be press-inserted into an end portion of a tube to flare the tube, and an inner circumferential portion constituting a fluid transfer path; a pipe joint body that has a tubular screwing portion having an external thread; and a union nut having an internal thread that is screwed with the external thread. The inner ring including the tube is inserted into the tubular screwing portion, and the tip-contracted outer-circumferential flared surface is pressed through the tube by a pressing portion of the union nut. The pressing portion of the union nut is formed into an inclined inner circumferential surface that is inclined in the same direction as the tip-contracted outer-circumferential flared surface with respect to the axis of the tubular screwing portion.

First claim

The invention claimed is:

1. A pipe-connecting device comprising:
an inner ring having: an inner circumferential portion constituting a fluid transfer path; and, an outer circumferential portion in which an outer-circumferential flared surface that is to be press-inserted from a tip end into an end portion of a fluid transfer tube to flare an inner circumferential portion of the end portion of the tube is formed at the tip end;
a pipe joint body or fluid apparatus that has a tubular screwing portion in which an external thread is formed on an outer circumferential side; and
a union nut in which an internal thread that is screwed with the external thread of the tubular screwing portion is formed,
the inner ring is inserted into the tubular screwing portion in a state where the inner circumferential portion of the end portion of the tube is flared, and the outer-circumferential flared surface is pressed against the union nut, which is screwed with the external thread of the tubular screwing portion, in a state where the tube is clamped, wherein
the outer-circumferential flared surface is formed into a convex curved surface in which the whole is radially outwardly convex,
a pressing portion, which is in the union nut and which presses the tube against the outer-circumferential flared surface, is formed into an inclined inner circumferential surface, which is inclined in a same direction as the outer-circumferential flared surface with respect to an axis of the tubular screwing portion, prior to fastening of the union nut,
wherein a press fitting portion is an area of engagement between the outer-circumferential flared surface of the inner ring and the end portion of the tube, said press fitting portion having a minimum diameter and a maximum diameter;
wherein an acute angle of the inclined inner circumferential surface with respect to the axis of the tubular screwing portion is set to be larger than an angle formed by a straight line connecting a place where the pressing fitting portion has the maximum diameter and a place where the outer-circumferential flared surface has the minimum diameter, and the axis of the tubular screwing portion;
and wherein a minimum diameter of the inclined inner circumferential surface of the union nut is set to be equal to or larger the minimum diameter of the press fitting portion, and the minimum diameter of the inclined inner circumferential surface of the union nut is set to be equal to or smaller than the maximum diameter of the press fitting portion;
wherein the inner ring is held in and abuts a recess of the pipe joint body or fluid apparatus, where the recess is radially offset from the fluid transfer path.

2. The pipe-connecting device according to claim 1 , wherein the outer-circumferential flared surface of the inner ring is formed such that, in the inner circumferential portion of the end portion of the tube to be flared, a portion of the tube that is to be flared is formed into a state having a diameter that is larger than a natural diameter of the inner circumferential flared surface of the tube, so as to form a convex curved surface.

3. The pipe-connecting device according to claim 1 , further comprising a seal element portion, which is formed in a basal end side of the inner ring, and a seal configuring portion, which is disposed in the pipe joint body or the fluid apparatus, and wherein the device is configured so that inner seal portions are formed as a result of press contact between the seal element portion and the seal configuring portion.

Assignees

• Nippon Pillar Packing

Inventors

• Fujii Makoto
• Iida Toshihide

Classifications

• F16L47/041

  the plastic pipe end being flared either before or during the making of the connection · CPC title

• F16L33/223

  the sealing surfaces being pressed together by means of a member, e.g. a swivel nut, screwed on or into one of the joint parts · CPC title

• F16L19/028 Primary

  the collars or flanges being obtained by deformation of the pipe wall · CPC title

• F16L13/147 Primary

  by radially expanding the inner part (F16L13/168 takes precedence) · CPC title

• F16L15/08

  with supplementary elements (F16L15/04 takes precedence) · CPC title