Pipe joint, air conditioner, method for producing connecting pipe, connecting pipe, and connection method

Patent metadata

Field	Value
Publication number	US-9797532-B2
Application number	US-201314373424-A
Country	US
Kind code	B2
Filing date	Mar 7, 2013
Priority date	Apr 2, 2012
Publication date	Oct 24, 2017
Grant date	Oct 24, 2017

Abstract

A pipe joint is connected with a connecting pipe, and includes a pipe joint body and a nut member. When the connecting pipe formed with a bead expanded in the radial direction is connected with this pipe joint, a male thread of the pipe joint body is engaged with a female thread of the nut member to hold the bead between a tapered face and a tapered face. In addition, the joined portion between the bead and the tapered face forms a first sealed portion, and a joined portion between the bead and the tapered face forms a second sealed portion. Still further, a tapered face of the pipe joint body is joined with the tapered face of the nut member to form a third sealed portion.

First claim

The invention claimed is:

1. A pipe joint connected with a connecting pipe through which a fluid flows, the pipe joint comprising:
a pipe joint body having an outer cylindrical surface with a male thread and a first insertion hole extending in an axial direction of the pipe joint body into which the connecting pipe is fitted, the first insertion hole including a first joining face joined with the connecting pipe having a shape matching an inverted truncated cone; and
a nut member having an inner cylindrical surface with a female thread and a second insertion hole extending in the axial direction of the pipe joint into which the connecting pipe is fitted, the second insertion hole including a second joining face having a shape matching a truncated cone; and
the connecting pipe having a bead expanded in a radial direction, the bead having first and second surfaces with shapes respectively matching the inverted truncated cone and truncated cone of the first joining face of the pipe joint body and the second joining face of the nut member,
wherein the bead is held between the first joining face and the second joining face by threading the female thread of the nut member onto the male thread of the pipe joint body and tightening the nut member onto the pipe joint body,
a joined portion between the first joining face and the first matching surface of the bead forms a first sealed portion that suppresses a leakage of the fluid, and a joined portion between the second joining face and the second matching surface of the bead forms a second sealed portion that suppresses a leakage of the fluid, and
the pipe joint body has an end face extending parallel with the second joining face of the nut member in a cross-sectional view and a shape matching the truncated cone of the nut member, and the end face of the pipe joint body is joined with an outer part of the second joining face of the nut member to form a third sealed portion that suppresses a leakage of the fluid.

2. The pipe joint according to claim 1 , wherein:
the first joining face comprises an inclined face inclined relative to an axial direction of the pipe joint body; and
an inclination angle of the first joining face is between 43 to 47 degrees.

3. The pipe joint according to claim 1 , wherein:
the second joining face comprises an inclined face inclined relative to an axial direction of the nut member; and
an inclination angle of the second joining face is between 43 to 47 degrees.

4. An air conditioner comprising:
a connecting pipe through which a coolant of a cooling cycle flows; and
the pipe joint according to claim 1 and connected to the connecting pipe.

5. The air conditioner according to claim 4 , wherein the coolant comprises R32 containing difluoromethane (CH 2 F 2 ).

6. A pipe joint connected with a connecting pipe through which a fluid flows, the pipe joint comprising:
a pipe joint body having an outer cylindrical surface with a male thread and a first insertion hole extending in an axial direction of the pipe joint body into which the connecting pipe is fitted, the first insertion hole including a first joining face joined with the connecting pipe having a shape matching an inverted truncated cone; and
a nut member having an inner cylindrical surface with a female thread and a second insertion hole extending in the axial direction of the pipe joint into which the connecting pipe is fitted, the second insertion hole including a second joining face having a shape matching a truncated cone; and
the connecting pipe having a bead expanded in a radial direction, the bead having first and second surfaces with shapes respectively matching the inverted truncated cone and truncated cone of the first joining face of the pipe joint body and the second joining face of the nut member,
wherein the bead is held between the first joining face and the second joining face by threading the female thread of the nut member onto the male thread of the pipe joint body and tightening the nut member onto the pipe joint body,
a joined portion between the first joining face and the first matching surface of the bead forms a first sealed portion that suppresses a leakage of the fluid, and a joined portion between the second joining face and the second matching surface of the bead forms a second sealed portion that suppresses a leakage of the fluid, and
end face of the pipe joint body is joined with part of an inner circumference of the second insertion hole of the nut member to form a third sealed portion that suppresses a leakage of the fluid, wherein:
either one of the first insertion hole of the pipe joint body or the second insertion hole of the nut member comprises a straight hole face parallel to an axis of the pipe joint body; and
when the connecting pipe comprising the bead expanded in the radial direction and formed at an end of the connecting pipe is connected, the bead is held between the first joining face and the second joining face, and is expanded in the radial direction so as to be joined with the straight hole face to form a fourth sealed portion that suppresses a leakage of the fluid.

7. The pipe joint according to claim 6 , wherein the straight hole face is formed near an opening of the first insertion hole of the pipe joint body.

8. A connecting pipe through which a fluid flows, the connecting pipe comprising:
a connecting pipe body;
a bead formed at an end of the connecting pipe body, the bead extending in the axial direction of the connecting pipe body and including a diameter-increasing portion extending in a radial direction of the connecting pipe body, a fixed diameter portion and a diameter-reducing portion narrowed in the radial direction from the fixed diameter portion; and
an outer cylindrical surface of the bead including a first surface having an inverted truncated cone shape configured to match a corresponding first joining face of a pipe joint body and a second face having a truncated cone shape configured to match a corresponding second joining face of a nut member to be threaded onto the pipe joint body;
wherein when the connecting pipe is connected with a pipe joint that includes the pipe joint body and the nut member, the pipe joint being formed with a male thread on an outer circumference and being formed with a first insertion hole into which the connecting pipe is fitted, and the nut member being formed with a female thread engaged with the male thread and being formed with a second insertion hole into which the connecting pipe is fitted,
the bead is held between the first joining face of the pipe joint body and the second joining face of the nut member when the male thread of the pipe joint body is engaged with the female thread of the nut member,
a joined portion between the bead and the first joining face forms a first sealed portion that suppresses a leakage of the fluid, and a joined portion between the bead and the second joining face forms a second sealed portion that suppresses a leakage of the fluid, and
an end face of the pipe joint body is joined with a part of an inner circumference of the second insertion hole of the nut member to form a third sealed portion that suppresses a leakage of the fluid; and

wherein when the connecting pipe is connected with the pipe joint that further comprises a straight hole face which is formed in either one of the first insertion hole of the pipe joint body or the second insertion hole of the nut member and which is parallel to an axis of the pipe joint body,
the bead extends in the radial direction and is joined with the straight hole face to form a fourth sealed portion that suppresses a leakage of the fluid.

9. A connection method for a pipe joint with a connecting pipe, the pipe joint compr

Assignees

• Makino Hiroaki
• Mitsubishi Electric Corp

Inventors

• Makino Hiroaki

Classifications

• B21D17/025

  by pressing tubes axially · CPC title

• F16L19/0212 Primary

  using specially adapted sealing means · CPC title

• F16L15/04

  with additional sealings · CPC title

• B21D39/04

  of tubes with tubes; of tubes with rods {(crimped pipe joints as such F16L13/14)} · CPC title

• F25B2500/221

  Preventing leaks from developing · CPC title