JP2002048275A - Tube fitting - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a tube fitting which has improved workability and can be easily connected, even in a narrow space by shortening the length of a connecting part and by preventing damages due to packing. SOLUTION: The tube fitting connects flare portions 1a, 1a formed on end parts of two pipes 1, 1 are formed, so as to have a substantially perpendicular flare shape by abutting the flare portions. The tube-fitting comprises a male nut 2, to be fitted on the outside of one of the pipes 1, which has a thread 7 on its outer periphery to be engaged with a cap nut 3; a fitting portion 9 for fitting to a seal surface portion 10 of the cap nut 3 and a packing attachment portion 6 at the end portion of the thread 7; the cap nut 3 to be fitted on the other pipe 1 with a female thread 8 on its inside peripheral surface and a seal surface portion 10; and a packing guide 4 to be built in the cap nut 3 together with a packing 5.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pipe joint for connecting a thin metal pipe which is difficult to thread.

[0002]

2. Description of the Related Art For example, as a fitting for a thin-walled stainless steel pipe such as an indoor pipe for water supply, after inserting both pipes from both ends of a fitting body, a fitting for connecting an outer peripheral surface of the fitting body by caulking, or an end of the pipe is used. A joint or the like is used, which is expanded and inserted from both ends of the joint main body, and is screwed and connected between the male nut and the joint main body. Among them, the joint which is connected by caulking the outer peripheral surface is, as shown in FIG.
2 are convex O-ring mounting portions 10 on the inner peripheral surfaces of both ends.
4, 104 are formed, and 0 rings 103, 103 are formed.
Is installed. When connecting, both pipes 10
After the first and the first 101 are inserted into the inner side of the O-rings 103 and 103, the swaging portion 10 formed on the outer peripheral surface of the joint body 102 is formed.
Both pipes 101, 101 inserted by caulking 5, 105
O-rings 103, 103 and the joint body 1
02 are connected to each other by pressing both end portions 106, 106 thereof. However, in such a connection structure, there is a problem that the detachment prevention force is weak, and after crimping, the detachment cannot be performed and the O-ring cannot be replaced.

[0003] In order to solve the above-mentioned problem, a joint for expanding and connecting an end of a pipe is used. As shown in FIG. 6, the expanded joint has convex engagement portions 103, 103 formed on the outer peripheral surfaces of the ends of both pipes 101, 101, and is inserted from both sides of the joint body 102. Stop 10
It is locked at 8,108. The joint main body 102 is provided with female threads 106, 106 on the inner peripheral surfaces at both ends, and the above-mentioned locking portions 108, 108 are provided at the end thereof. 105 is attached. Both nuts 104 are connected to both pipes 10.
1, 101, and external threads 107, 10
7 are provided. The joint body 102 and the nuts 104 are connected by screwing and tightening.

[0004]

In the above-mentioned expansion joint, since the joint structure is complicated and has a long connection structure, the workability is poor and the connection work in a narrow place is difficult. There is a problem that it is difficult. Further, both pipes 101,
When the 101 is inserted into the joint main body 102, the distal end of the pipe is inserted while expanding the inner peripheral surfaces of both the packings 104, 104, so that there is a high risk of damaging the side surface or the inner peripheral surface of the packing. The packings 104, 104
Since the two pipes 101 and 101 are in contact with only the repulsive force that is pushed and spread, there is a structural defect that fluid leakage easily occurs when no internal pressure is generated in the pipes.

[0005]

DISCLOSURE OF THE INVENTION The present invention solves the above-mentioned problems, and simplifies the structure of a joint without using a joint body, shortens the length of a connecting structure, and prevents damage to packing. It is another object of the present invention to provide a piping joint which can enhance the degree of freedom of construction and can be easily connected even in a narrow place.

[0006] In order to achieve the above object, the present invention provides:
A pipe joint for connecting both flared portions of both pipes in which the ends of the pipes are flared substantially at right angles in the axial direction,
Externally fitted to one of the pipes, has an external thread portion for screwing with a cap nut on the outer periphery, and at its end, a fitting portion that fits with the sealing surface portion of the cap nut, and a packing mounting portion are provided, and the packing is provided. It is composed of a mounted male nut, a cap nut which is externally fitted to the other pipe, has a female thread on the inner peripheral surface, and has a sealing face, and a packing guide which is provided inside the cap nut and is fitted with packing. A pipe joint characterized in that when the male nut and the cap nut are screwed together, both packings are tightly sealed to the back side surfaces of both flare portions.

Further, a radially outward flange portion is provided at the outer peripheral end of the packing guide to form a surface to which the side surface of the packing is in close contact, and the cap nut can be installed from the flange portion. In the case of using the one that is made as above, the friction between the packing and the cap nut can be eliminated, the packing can be protected, and the strength of the packing guide increases,
Both pipes can be firmly connected.

Further, the length of the sealing surface portion of the cap nut is made longer than that of the normal one, so that the cap nut is provided between the two flared ends butted in the axial direction, or between the packing guide and the cap. Provide a space between the nuts, in that space,
In the case of a member that has no sealability at all, if a member that can be connected and connected as an intermediate member is used, the functions of the piping equipment and piping The whole arrangement can be made compact by constituting it as an intermediate member.

As described above, the male nut and the cap nut have a simple structure that can be connected only by screwing and tightening.
Eliminates the need for a normal joint body, shortens the length of the connection,
Sealing the back side surfaces of both flares prevents damage to the packing and has a strong pull-out prevention force.In addition, both packings are compressed and tightly sealed to the surfaces that come into contact with each other. Even in a state where no internal pressure is generated, the sealing performance can be ensured.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a longitudinal section showing a connection state of a pipe joint according to an embodiment of the present invention, and FIG.
FIG.

In FIG. 1, reference numerals 1 and 1 denote pipes connected to each other. The ends of the pipes 1 and 1 are flared to form flare portions 1a, 1a at substantially right angles. Matched.

Reference numeral 2 denotes a male nut having an external thread portion for screwing with the cap nut 3 on the outer peripheral surface, and a fitting portion 9 for fitting with the sealing surface portion 10 of the cap nut 3 and a packing mounted on an end side thereof. A portion 6 and a pressing surface 11 are provided, and a radially outward flange portion 13 is provided at a rear end portion. And one pipe 1
Is slidably fitted on the outer peripheral surface of the lens and is prevented from falling off by the flare portion 1a.

Reference numeral 3 denotes a cap nut, which has a female thread 8 on the inner peripheral surface, a seal face 10 provided and a pressing face 12. Then, a packing guide 4 described later is internally provided and slidably fitted on the outer peripheral surface of the other pipe 1,
It is prevented from coming off by the flare part 1a.

Reference numeral 4 denotes the above-mentioned packing guide, wherein the outer peripheral surface is a packing mounting portion 4a, one end surface is a pressing surface, the other end surface is a pressure receiving surface, and the packing guide is detachably mounted on the cap nut 3. It is prevented from coming off by the flare part 1a.

Reference numerals 5 and 5 denote packings made of a material such as rubber or synthetic resin having elasticity, and are mounted on the packing mounting portion 6 of the male nut 2 and the packing mounting portion 4a of the packing guide 4. Incidentally, the packings 5 and 5 are detachable over both flare portions.

An operation for connecting the pipe joint having the above-described structure and the two pipes 1 and 1 will be described.

First, the male nut 2 with the packing 5 attached
Is slidably fitted on the outer peripheral surface of one of the pipes 1 and the end of the pipe is flared to form a substantially right-angled flare portion 1a.
To form Then, the packing guide 4 with the packing 5 mounted therein is housed in the cap nut 3, and is slidably fitted on the outer peripheral surface of the other pipe 1, and the end of the pipe is flared to form a substantially right angle. Is formed.

After the preparation is completed, the two flares 1a, 1a are butted in the axial direction, and the male nut 2 externally fitted to one of the pipes 1 is slid, whereby the back side 1b of the flare 1a is slid. To the male nut 2 and the cap nut 3 by sliding the cap nut 3 externally fitted to the other pipe.
And screwed together to connect.

As described above, the two flares 1a, 1a and the packing guide 4 are collectively clamped and fixed by screwing together, and at the same time, the packing 5 mounted on the male nut 2 is attached to the packing mounting portion. 6 and the back side 1b of the flare portion 1a, the back side 1b and the sealing surface 10 of the cap nut 3 are sealed.
The packing 5 mounted on the packing guide 4 is compressed between the back side surface portion 1b of the flare portion 1a and the pressing surface portion 12 of the cap nut 3, and seals the back side surface portion 1b and the sealing surface portion 10 of the cap nut 3. are doing. The repulsive force generated by the compression of the packings 5 and 5 and the repulsive force generated by the pinching of the flare portions 1a prevent the loosened screws from being loosened, thereby completing the connection. In the screw tightening, in the hand tightened state, the repulsive force of both packings 5 and 5 and both flares 1a and 1a causes the gap between the flange 13 of the male nut 2 and the end of the cap nut 3. In addition, there is a gap that can be judged to be insufficiently tightened at first glance, and since connection is not completed unless tightening with a tool, it is possible to prevent forgetting to tighten and visually check the tightening state .

Further, as the above packing guide,
In the case where the outer peripheral end is provided with an outwardly directed collar portion at the outer peripheral end and the side surface of the packing is configured to be in close contact with the outer peripheral end, the length of the sealing surface portion 10 of the cap nut 3 is set in advance. The packing guide 4 is extended by the thickness of the brim portion 4b. Then, the friction between the packing 5 and the cap nut 3 is eliminated, and the packing 5 is protected, the strength of the packing guide 4 is increased, and both pipes can be firmly connected.

By the way, in the above-mentioned embodiment, the ordinary connection structure is described. However, as in claim 3, the length of the sealing surface portion of the cap nut is made longer than that of the ordinary one, and A space is provided between the two flared ends that abut against each other, or between the packing guide and the cap nut, so that even a member with no sealing property can be connected as an intermediate member to that space. In the case of using the seal member, it is preferable to use a seal member in which the length of the sealing surface portion 10 is previously increased by the length of the intermediate member. And the functions of piping equipment, piping members, etc. used for installation,
By configuring and interposing the intermediate member, such a changeable intermediate member is not required, and the entire arrangement can be made compact. For example, as a means for removing dust, dirt, rust and the like of a fluid, a strainer made of a material such as porous sintered metal or punching metal is constituted as an intermediate member and interposed therebetween, so that Y is commonly used. Piping members that must be connected, such as a character-shaped strainer, can be eliminated.

Further, as an intermediate member having no sealing property, the length of the pipe can be adjusted by interposing a length adjusting intermediate ring or the like. Such an intermediate ring can be used as long as it is made of a hard material other than metal, and its shape is mainly a plate-like ring,
Alternatively, it is preferable to use a pair of semicircular rings in a plate shape. Then, the intermediate ring is interposed between both butted ends of the flares, or between the packing guide 4 and the cap nut 3, or both, and the intermediate rings are replaced to adjust the length. It is desirable to do. On the other hand, as the intermediate member having a sealing property, rubber,
With a packing made of a material such as synthetic resin,
The double sealing structure can improve sealing performance and prevent vibration.

[0023]

As described above, the pipe joint according to the present invention is a pipe joint in which both flared portions formed substantially at right angles are butt-connected in the axial direction and the back side surfaces of both flares are sealed. By setting the location, the protection of the packing is ensured without making the welded part of the welding tube a problem, etc.
It is possible to obtain a connection structure having a strong detachment prevention force. In addition, the structure of the joint has a simple structure,
The length of the connecting part can be shortened by eliminating the need for a normal joint body, and even from a state perpendicular to the axial direction.
Because it can be attached and detached, it can be easily connected even in a small place. In addition, since the pull-out direction side is used as the sealing portion, a connection structure with high sealing performance and safety is obtained as a result.

Further, when the packing guide is provided with a radially outward flange at the outer peripheral end of the packing guide so that the side surface of the packing is in close contact with the packing guide, the packing and the cap nut are used. In addition to eliminating the friction with the packing, the packing is protected and the strength of the packing guide is increased, so that both pipes can be connected more firmly. In addition, the structure is suitable for connecting the packing guide and the cap nut with an intermediate member interposed therebetween.

Further, the length of the sealing surface portion of the cap nut is made longer than that of a normal one, so that the cap nut is provided between the two flared ends butted with each other in the axial direction, or with the packing guide. When a space is provided between the cap nuts and a member that can be connected and connected as an intermediate member even in a member having no sealing property in the space, whether or not the sealing property is involved, By applying the function of piping equipment, piping members, etc. used in the arrangement to this intermediate member by applying that it can be interposed as an intermediate member, The changeable components are not required, so that the entire arrangement can be made compact, the cost can be reduced, and the arrangement can be rationalized and improved.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing a connection state of a pipe joint according to an embodiment of the present invention.

FIG. 2 is a side view of FIG.

FIG. 3 is an enlarged vertical sectional view of a main part showing a modification of the packing guide.

FIG. 4 is an enlarged longitudinal sectional view of a main part showing an example of use in which an intermediate member is interposed.

FIG. 5 is an enlarged longitudinal sectional view of a main part showing a connection state by a conventional caulking joint.

FIG. 6 is an enlarged longitudinal sectional view of a main part showing a connection state by a conventional pipe-type joint.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Piping 1a Flare part 1b Back side part of flare part 2 Male nut 3 Cap nut 4 Packing guide 4a Flange part of packing guide 5 Packing 6 Male nut packing mounting part 7 Male screw part of male nut 8 Female screw part of bag nut 9 Male nut Fitting part 10 Seal face part of cap nut 11 Press face part of male nut 12 Press face part of cap nut 13 Flange part of male nut

Claims (3)

[Claims] 1. A pipe joint for connecting two flared portions of two pipes whose ends are flared at a substantially right angle in an axial direction, wherein the two flared portions are externally fitted to one of the pipes, and a cap nut is provided on an outer peripheral surface thereof. And a threaded threaded portion, and a fitting portion and a packing mounting portion fitted to the sealing surface portion of the cap nut at the end thereof are provided, and the male nut with the packing mounted thereon is externally fitted to the other pipe,
It has a female screw part on the inner peripheral surface, a cap nut provided with a seal face part, and a packing guide mounted inside the cap nut and fitted with packing, and is screwed and tightened with a male nut and a cap nut. A pipe joint characterized in that both packings are tightly sealed to the back side surfaces of both flares. 2. The packing guide according to claim 1, wherein a radially outward flange portion is provided at an outer peripheral end of the packing guide so as to form a surface on which the side surface of the packing is in close contact, so that the cap nut can be housed from the flange portion. Plumbing fittings. 3. The length of the sealing surface portion of the cap nut is made longer than that of a normal one, so that a space is provided between the two flared ends butted in the axial direction, or between the packing guide and the cap nut. 3. The pipe joint according to claim 1, wherein said pipe joint is provided so that even a member having no sealing property can be connected as an intermediate member in said space.