JP2010159784A - Pipe connection structure and pipe connection method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a pipe connection structure and a pipe connection method which prevent the risks of leakage of transferred medium or an occurrence of fire by connecting pipes with threads of a bolt part and a nut part. <P>SOLUTION: The pipe connection structure, which connects a first pipe 1 and a second one 2 having hollow holes 1a, 2a respectively, includes: the nut part 3, which is attached to the first pipe 1 and which has a pressing part 3b that presses a flare part 1b formed at the end of the first pipe 1; the bolt part 4, which is attached to the second pipe 2 and which has a male thread part 4a that is fastened to the nut part 3 by screwing on the outside circumferential surface and a portion 4b facing a flare part 2b formed at the end of the second pipe 2; and an adaptor 5, which is arranged between the flare part 1b and flare part 2b and which has a through-hole 5c that is communicated with the respective hollow holes 1a, 2a of the first pipe 1 and second pipe 2. The bolt part 4 and the nut part 3 are tightened by a predetermined torque to connect the first pipe 1 to the second pipe 2. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a pipe connection structure and a pipe connection method used for connecting a pipe for transferring a refrigerant of an air-conditioning refrigeration cycle.

  Conventionally, as this type of pipe connection structure, as shown in FIG. 3, after fitting the nut portion 32 to the first metal pipe 30 among the first and second metal pipes 30 and 31 to be connected, A flare 30a is integrally formed at the end of the metal pipe 30, a union 33 having a male thread 33a is integrally joined to the end of the second metal pipe 31, and the flare 30a is joined to the union 33. Some are configured by forming a conical sealing surface corresponding to the shape. And in the said structure, the nut part 32 is fastened to the external thread part 33a of the union part 33, the flare part 30a is directly press-contacted on the sealing surface of the union part 33, and the 1st metal piping 30 is carried out by the metal seal of metal surfaces. And a pipe connection structure for connecting the second metal pipe 31 is well known.

  In the pipe connection structure, when vibration or the like is applied to the pipe connection part, the vibration or the like causes the metal seal part to be worn or deformed, and the surface pressure of the metal seal part is lowered and sealed. There is a problem that degrades the function. Therefore, as a solution to this problem, a pipe connection structure in which an elastic member 34 that elastically compresses and deforms elastically by the tightening of the nut portion 32 between the nut portion 32 and the flare portion 30a is interposed. Has been proposed (see, for example, Patent Document 1).

JP 2003-214570 A (paragraphs 0002 to 0008, FIG. 3)

  According to the pipe connection structure proposed in Patent Document 1, the flare part crimping force for the metal seal is not directly generated by the tightening force of the nut part 32, but is interposed between the nut part 32 and the flare part 30a. The flare part crimping force is generated by the elastic force of the elastic member 34 that has been produced. Therefore, even when a force due to vibration or the like is applied to the pipe connection portion, the elastic member 34 can elastically expand and contract to relieve the force applied to the metal seal portion, and as a result, wear of the metal seal portion due to vibration or the like. , Deformation and the like can be suppressed.

  However, the said pipe connection structure joins integrally the union part which has an external thread part in the edge part of metal piping by welding. This is because it is difficult to pre-manufacture and place an integrated body of metal pipe and union part when replacing the existing pipe. Therefore, the metal pipe and the union part are processed separately in a factory, etc. A construction method for connection is taken on site, and welding is generally used for this connection construction method.

  As in the pipe connection structure, when connecting the union part to the end of the metal pipe, the method using welding may cause a transfer medium due to poor connection due to a difference in the welding technique of the operator, for example, leakage of refrigerant, Alternatively, there is a problem that sparks are scattered around by welding work at the piping site, causing a fire to occur.

  The present invention has been made to solve the above-mentioned problems. By connecting a pipe and a pipe with a screw using a bolt part and a nut part, the pipe connection structure prevents a leakage of a transfer medium or a fire from occurring. And a pipe connection method.

  The pipe connection structure according to the present invention is a pipe connection structure that connects a first pipe and a second pipe each having a hollow hole, and is attached to the first pipe, and an end portion of the first pipe. A nut portion having a pressing portion for pressing the flare portion formed on the outer peripheral surface, a male screw portion that is attached to the second pipe and is screw-coupled to the nut portion on the outer peripheral surface, and an end portion of the second pipe Between the bolt part having a portion facing the flare part formed on the first pipe, the flare part formed on the end part of the first pipe, and the flare part formed on the end part of the second pipe. Provided with an adapter having a through hole communicating with each of the hollow holes of the first pipe and the second pipe, and tightening the bolt part and the nut part with a predetermined torque to the first pipe And the second pipe.

  According to the pipe connection structure according to the present invention, the pipe and the pipe can be connected without using welding. Accordingly, it is possible to eliminate the possibility that a transfer medium leaks due to poor connection due to a difference in welding technique of the operator, or that a spark is generated due to a spark scattered around by welding work at the piping site.

  Preferred embodiments of a pipe connection structure and a pipe connection method according to the present invention will be described below with reference to the accompanying drawings. The present invention is not limited to the embodiments.

Embodiment 1 FIG.
1 is a cross-sectional view illustrating a pipe connection structure according to Embodiment 1 of the present invention. In FIG. 1, for example, the first and second metal pipes 1 and 2 constituting the refrigerant pipe of the air-conditioning refrigeration cycle are made of an aluminum alloy. 1a and 2a are provided. And after attaching the nut part 3 to the 1st metal piping 1, the flare part 1b expanded conically at the end part is integrally molded. The second metal pipe 2 is integrally formed with a flare portion 2b that expands in a conical shape at the end after the bolt portion 4 is mounted. The nut part 3 and the bolt part 4 are also made of an aluminum alloy.

  Between the flare part 1b of the first metal pipe 1 and the flare part 2b of the second metal pipe 2, an adapter 5 made of, for example, a rubber-based elastic member is disposed. The adapter 5 is configured to show a side view in FIG. 2A, a front view in FIG. 2B, and a perspective view in FIG. That is, the adapter 5 is configured to have an outer shape that shows a shape in which two truncated cones formed by cutting the top of the cone are joined together. The flare portion 1b of the metal pipe 1 is in contact with one conical surface 5a of the adapter 5, and the flare portion 2b of the metal pipe 2 is in contact with the other conical surface 5b. Further, the adapter 5 is formed with a through hole 5c penetrating from the top of the cone, which is the center of the adapter 5, to the other top, and the inner diameter of the through hole 5c is the first and second metal. The inner diameters of the hollow holes 1a and 2a provided in the pipes 1 and 2 are the same.

  The bolt part 4 has a cylindrical shape, a male screw part 4a is formed on the outer peripheral surface, and a conical shape corresponding to a conical shape of the flare part 2b, for example, a part facing the flare part 2b at the tip part of the bolt part 4 Surface 4b is formed.

  The nut portion 3 is formed with a female screw portion 3 a that is screw-coupled to the male screw portion 4 a of the bolt portion 4, and a conical pressing portion 3 b for pressing the flare portion 1 b onto one conical surface 5 a of the adapter 5. Is formed.

  The pipe connection structure according to the first embodiment is configured as described above. Next, a pipe connection method will be described. In FIG. 1, first, the nut portion 3 is mounted on the outer periphery of the first metal pipe 1, and the bolt portion 4 is mounted on the outer periphery of the second metal pipe 2.

  Next, a flare portion 1 b that expands in a conical shape is formed at the end portion of the first metal pipe 1, and a flare portion 2 b that expands in a conical shape is formed at the end portion of the second metal pipe 2.

  Thereafter, the adapter 5 is arranged so that the hollow hole 1a of the first metal pipe 1, the hollow hole 2a of the second metal pipe 2, and the through hole 5c of the adapter 5 communicate with each other between the flare part 1b and the flare part 2b. Is disposed. And the internal thread part 3a of the nut part 3 is fitted to the outer peripheral surface of the bolt part 4, and it fastens to the external thread part 4a with a predetermined tightening torque.

  By tightening the nut portion 3, the flare portion 1 b of the first metal pipe 1 is pressed against one conical surface 5 a of the adapter 5, and the flare portion 2 b of the second metal pipe 2 is pressed against the other conical surface 5 b of the adapter 5. Pressed against. Since the adapter 5 is elastically compressed by a predetermined amount by this tightening, an elastic force based on the compression deformation is generated. Accordingly, the elastic force of the adapter 5 always acts on the flare portion 1 b of the first metal pipe 1 and the flare portion 2 b of the second metal pipe 2. Thereby, the seal | sticker part closely_contact | adhered between the flare part 1b and the conical surface 5a of the adapter 5 and the flare part 2b and the conical surface 5b of the adapter 5 can be formed.

  As described above, according to the pipe connection structure and the pipe connection method according to Embodiment 1, the first metal pipe 1 and the second metal pipe 2 can be connected without using welding. Therefore, it is possible to eliminate the possibility of refrigerant leakage due to poor connection due to the difference in welding technique of the worker or the occurrence of a fire due to sparks scattered by the welding work at the piping site.

  Further, the adapter 5 disposed between the flare portion 1b of the first metal pipe 1 and the flare portion 2b of the second metal pipe 2 is constituted by an elastic member, for example, the first metal pipe 1 Even when a force due to vibration or the like is applied to the pipe connection portion between the second metal pipe 2 and the second metal pipe 2, the adapter 5 made of an elastic member elastically expands and contracts, and the flare portion 1b and the conical surface 5a of the adapter 5 In addition, the force applied to the seal portion between the flare portion 2b and the conical surface 5b of the adapter 5 can be relaxed, and as a result, wear and deformation of the seal portion due to vibrations and the like can be suppressed.

  In the first embodiment, the case where the present invention is applied to connection between metal pipes has been described. However, the present invention is not limited to metal pipes connected to each other. Connection of non-metallic pipes such as hard resin may be used, and non-metallic pipes may be connected to each other.

  Moreover, in the said Embodiment 1, although the case where this invention was applied to the connection of metal piping which transfers the refrigerant | coolant of the refrigerating cycle for an air conditioning was demonstrated, this invention is not limited to the transfer of a refrigerant | coolant. Of course, the present invention can also be applied to transfer of a medium other than the refrigerant.

It is sectional drawing explaining the piping connection structure which concerns on Embodiment 1 of this invention. It is a figure which shows the adapter used for the piping connection structure which concerns on Embodiment 1 of this invention. It is sectional drawing explaining the conventional piping connection structure.

DESCRIPTION OF SYMBOLS 1, 30 1st metal piping 1a, 2a Hollow hole 1b, 2b, 30a Flare part 2, 31 2nd metal piping 3, 32 Nut part 3a Female thread part 3b Press part 4 Bolt part 4a, 33a Male thread part 4b Conical shape Surface 5 Adapter 5a, 5b Conical surface 5c Through-hole 33 Union part 34 Elastic member

Claims (4)

A pipe connection structure for connecting a first pipe and a second pipe each having a hollow hole,
A nut portion that is attached to the first pipe and has a pressing portion that presses a flare formed at an end of the first pipe;
A bolt part that is attached to the second pipe and has a male screw part that is screw-coupled to the nut part on the outer peripheral surface, and a part that faces a flare part formed at an end part of the second pipe;
Each of the first pipe and the second pipe is disposed between a flare formed at the end of the first pipe and a flare formed at the end of the second pipe. An adapter having a through hole communicating with the hollow hole of
A pipe connection structure, wherein the bolt part and the nut part are tightened with a predetermined torque to connect the first pipe and the second pipe.   The pipe connection structure according to claim 1, wherein the adapter is formed of an elastic member.   The adapter has an outer shape that abuts on a flare formed at an end portion of the first pipe and abuts on a flare portion formed at an end of the second pipe. The pipe connection structure according to claim 1 or claim 2. A pipe connection method for connecting a first pipe and a second pipe each having a hollow hole,
Attaching a nut part on the outer periphery of the first metal pipe 1 and attaching a bolt part on the outer periphery of the second metal pipe;
Forming a flared portion expanding conically at the end of the first metal pipe and forming a flared portion expanding conically at the end of the second metal pipe;
Between the flare formed at the end of the first metal pipe and the flare formed at the end of the second metal pipe, the hollow hole of the first metal pipe and the second Disposing an adapter having a through hole communicating with a hollow hole of a metal pipe;
Fitting the nut portion to the outer peripheral surface of the bolt portion, and tightening the nut portion and the bolt portion with a predetermined tightening torque;
A pipe connection method comprising the steps of:

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