JPH0914533A - Pipe joint - Google Patents

Abstract

PURPOSE: To provide a pipe joint whereby connecting workability can be improved while improving reliability of sealability, durability, etc., in a connection part of a pipe. CONSTITUTION: A pipe joint comprises a nipple 2 and a socket 3 of cylindrical shape fitted to each other, connecting means 4 of connecting the nipple 2 to the socket 3 and the first/second seal members respectively provided in a fitting part 5 and an opposed end face part 6 of the nipple 2 and the socket 3, and the second seal member consists of a ring-shaped metal packing 16.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a pipe joint. More specifically, the present invention relates to a pipe joint used for piping such as a refrigerant transportation pipe and a flexible hose in an automobile, a room air conditioner, a refrigerator or a refrigeration system.

[0002]

2. Description of the Related Art As a conventional pipe joint, a funnel-shaped flare is applied to the tip of a pipe, and then the flare portion is fastened to a male screw pipe of a main body of a device by a lock nut to connect the pipe. Alternatively, in order to improve the sealing property, a packing is interposed between the flare portion and the pipe of the apparatus main body. In addition, the pipe is not processed at all, and a tightening ring made of an elastic material is provided between the lock nut and the male screw pipe of the main body of the device, and the inner circumference of the tightening ring is tightened by tightening the lock nut. Some reduce the surface to seal the joints of the pipes while simultaneously connecting the pipes.

[0003]

However, in each of the above-mentioned pipe joints, since the lock nut having the female thread processed is rotated and tightened to the male thread pipe having the male thread processed, it is troublesome and the workability is deteriorated. To do. In addition, in order to secure the pipe connection and to secure the sealing property, it is necessary to tighten the pipe with the proper arrangement angle and the proper torque. There is a problem that reliability such as durability and durability cannot be obtained. In order to solve this problem, it is possible to always manage the tightened state of the pipe, but in the case of on-site construction, since a simple tool is used, the accuracy and flare caused by the variation in the pressing force during flare molding It is extremely difficult due to the twist of the connection part or the lock nut.

[0004] In the case of tightening with the lock nut, all are first tightened manually, and then the additional tightening is performed using a tool such as a spanner or a wrench, but there is a fear of forgetting the additional tightening. Further, it is often very difficult to completely eliminate the leakage only by using a sealing member such as rubber or synthetic resin for sealing.

In view of the above circumstances, the present invention provides a pipe joint which can improve reliability such as sealing property and durability of a connecting portion of a pipe and workability of connection. To aim.

[0006]

DISCLOSURE OF THE INVENTION A pipe joint according to the present invention comprises a cylindrical nipple and a socket which are fitted to each other, a fastening means for connecting the nipple and the socket, and a fitting portion of the nipple and the socket. A first seal member and a second seal member respectively provided on the end face portion,
The second seal member is made of a ring-shaped metal packing.

The metal packing is preferably made of metal and an elastic body.

The fastening means is a cap nut having a U-shaped cross section which is fitted on one of the nipple and the socket on the outer circumference of the facing end surface portion, and in the radial direction of the large diameter cylindrical portion of the cap nut. A lock pin is provided, and the lock pin is fitted into the large-diameter cylindrical portion, and is fitted into a spigot groove formed in an outer surface of the other of the nipple and the socket and extending in a rotation direction of about 90 °. Preferably.

[0009]

According to the pipe joint of the present invention, the gas slightly permeated from the first seal member can be completely sealed by the metal seal of the metal packing which is the second seal member.

As a fastening means, a lock pin provided on the cap nut is fitted into, for example, a spigot groove formed on the outer surface of the nipple and extending in a rotation direction of about 90 °, and then the cap nut is rotated along the spigot groove to form a nipple. By connecting the socket and the socket, the connection work becomes easy.

[0011]

The pipe joint of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 is a partial sectional view showing an embodiment of the pipe joint of the present invention, FIG. 2 is an exploded perspective view of the pipe joint shown in FIG. 1, and FIG. 3 is a perspective view showing an embodiment of the metal packing shown in FIG. Is.

As shown in FIGS. 1 to 3, the pipe joint 1 includes a cylindrical nipple 2 and a socket 3 which are fitted to each other.
And fastening means 4 for connecting the nipple 2 and the socket 3
And a first seal member and a second seal member provided on the fitting portion 5 of the nipple 2, the socket 3, and the facing end surface portion 6, respectively.

The nipple 2 has a small-diameter fitting portion 8 which is fitted in the socket 3 with a collar portion 7 formed in an intermediate portion therebetween, and a connecting portion 9 which connects a pipe or a hose P to the inside thereof. The socket 3 is formed with a large-diameter fitting portion 10 into which the small-diameter fitting portion 8 is inserted and a connecting portion 11 that connects a pipe or a hose P inside the socket 3. Further, two peripheral grooves 12a and 12b are formed on the outer peripheral surface of the small-diameter fitting portion 8, and each peripheral groove 12a and 12b is formed.
O-rings 13a, 1 which are the first sealing members, 12b
3b is mounted. The material of the O-rings 13a and 13b can be appropriately selected depending on the fluid transported by the pipe or the hose P, for example, gas such as CFC gas R-22 and CFC gas R-134, or ester oil. Although not particularly limited in the present invention, the inner O-ring 13a has a rubber having excellent oil resistance, for example, nitrile-butadiene rubber (NB
R), chloroprene rubber (CR), chlorosulphonated rubber (CSM), hydrogenated nitrile-butadiene rubber (H-NBR), acrylic rubber (AR), hydrin rubber (CHR), etc. can be used, and the outer O The ring 13b includes rubber having excellent gas barrier properties, such as butyl rubber (IIR) and chlorinated butyl rubber (CL-II).
R), brominated butyl rubber (Br-IIR), hydrogenated nitrile-butadiene rubber (H-NBR) and the like can be used. Further, as the resin product, Teflon resin, nylon resin, polyester resin, polypropylene and polymer alloy materials thereof can be used. As a result, a highly reliable seal can be obtained. Although two O-rings are mounted as the first seal member in this embodiment, the present invention is not limited to two O-rings, and one O-ring or three O-rings is used. You may make it equip with more than one O-ring. Besides the O-ring, a U-type packing, a V-type packing, a square type packing, or the like can be used. An annular groove 15 is formed in the end surface 14 of the flange 7 facing the socket 3.
A metal packing 16 which is a second seal member is attached to. As the metal packing 16, a material excellent in self-lubrication, such as copper, lead, tin, or an alloy thereof is used, but is not limited to these in the present invention, and as shown in FIG. Two metals 16a made of copper or the like and an elastic body 16 made of rubber or synthetic resin
b can also be laminated. As the rubber, natural rubber (NR), synthetic natural rubber (IR), or the like can be used, but butyl rubber (IIR) system and hydrogenated nitrile-butadiene rubber (H-NBR) having excellent gas barrier properties are used. It is preferably used. The end surface 18 of the collar portion 17 formed on the opening side of the large diameter fitting portion 10 of the socket 3 facing the metal packing 16 has a height of 0.
An annular protrusion 19 having a diameter of 5 mm to 5.0 mm and a tip angle of 60 ° to 120 ° is formed, and the metal packing 16 and the protrusion 19 are crimped by the fastening means 4 at a pressure of 4 to 7 kgfcm or more. It is designed to be in torque. Further, as will be described later, a spring plunger for preventing the tightening torque from rotating in the loosening direction after the completion of tightening is provided at the contact surface between the nipple 2 and the cap nut. In this embodiment, the metal packing 16 is attached to the end surface 14 of the collar portion 7 of the nipple 2, and the protrusion 19 is provided on the end surface 18 of the collar portion 17 of the socket 3.
However, the present invention is not limited to this, and a projection may be formed on the end surface 14 of the nipple 2 and a metal packing may be attached to the end surface 18 of the socket 3. .

The fastening means 4 is provided in the radial direction of the cap nut 20 having a U-shaped cross section and fitted in the socket 3 on the outer periphery of the facing end surface portion 6, and the large diameter cylindrical portion 21 of the cap nut 20. A lock pin 22 that is formed on the outer surface 23 of the nipple 2 that is fitted in the large-diameter cylindrical portion 21 and that extends in a rotation direction of approximately 90 ° (a quadrant). It is fitted in the groove 24. To connect the nipple 2 and the socket 3 by the fastening means 4, first, the lock pin 22 is fitted into the inlay groove 24 from the end face 14 side of the collar portion 7, and then the inlay groove 2 is inserted.
4 to the tip 25 of the inlay groove 24 along with the cap nut 20
Rotate approximately 90 ° to lock pin 22 and cap nut 20.
With the small diameter cylindrical portion 26, the flange portion 17 of the socket 3 is sandwiched. Further, the spigot groove 24 and the lock pin 22 have a 180 ° angle, as shown in FIGS.
The cap nut 20
The rotation of is smooth, and the nipple 2 and the socket 3 are securely connected. When the cap nut 20 is rotated, a pair of pinching flat surfaces 28 are formed on the outer peripheral surfaces of the cap nut 20 and the large-diameter flange 27 of the nipple 2 in order to facilitate the rotation work. Further, when the cap nut 20 is tightened and after the tightening is completed, the ratchet 3 formed on the end surface 29 of the cap nut 20 for preventing the cap nut 20 from rotating in the reverse direction.
0 and a reverse-rotation preventing means composed of a spring plunger 31 fitted in the large-diameter collar portion 27 of the nipple 2. The ratchet 30 includes a plurality of protrusions 32 or holes, and the spring plunger 31 includes a spring 33 and a steel ball 34 urged by the spring 33.
In the present invention, the cap nut may be fitted in the nipple and the lock pin may be fitted in the pilot groove formed on the outer surface of the socket. The material of the nipple, socket and cap nut is not particularly limited, but copper, brass, bronze, stainless steel, aluminum alloy or the like can be used.

[0016]

As described above, in the pipe joint of the present invention, since the second sealing member made of the metal packing is mounted on the facing end surface portions of the nipple and the socket, when the fastening means tightens the facing member, The nipple and the socket are tightly metal-bonded (metal seal) on the end face portion, and it is possible to obtain a highly reliable complete seal that could not be achieved only by the first seal member composed of the O-ring of rubber or synthetic resin. The sealability can be maintained for a long period of time.

Further, as the fastening means, the lock pin of the cap nut is fitted into the pilot groove formed on the outer surface of the nipple to rotate the cap nut by about 90 °, so that the connection between the nipple and the socket is easy. Therefore, the workability can be improved.

[Brief description of the drawings]

FIG. 1 is a partial cross-sectional view showing an embodiment of a pipe joint of the present invention.

FIG. 2 is an exploded perspective view of the pipe joint in FIG.

3 is a perspective view showing an example of the metal packing in FIG. 1. FIG.

[Explanation of symbols]

 1 Pipe Joint 2 Nipple 3 Socket 4 Fastening Means 5 Fitting Part 6 Opposing End Face 16 Metal Packing

Claims (3)

[Claims] 1. A cylindrical nipple and a socket to be fitted to each other, a fastening means for connecting the nipple and the socket, and a first seal member provided on the fitting portion of the nipple and the socket and the facing end surface portion, respectively. And a second seal member, wherein the second seal member is a ring-shaped metal packing. 2. The pipe joint according to claim 1, wherein the metal packing is made of a metal and an elastic body. 3. A cap nut having a U-shaped cross section fitted into one of a nipple and a socket on the outer circumference of the facing end surface portion, and a diameter of the large-diameter cylindrical portion of the cap nut. Direction, the lock pin is fitted in the large-diameter cylindrical portion, and the lock pin is fitted in a spigot groove formed on the outer surface of the other of the nipple and the socket and extending in a rotation direction of about 90 °. The pipe joint according to claim 1, wherein the pipe joint is formed.