JP2504715Y2 - Pipe fitting - Google Patents

Description

[Detailed description of the device]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pipe joint used for connecting a metal pipe.

[0002]

2. Description of the Related Art Conventionally, in a pipe joint provided with a joint body, a cap nut screwed to the joint body, and an elastic body such as rubber requiring compression for watertightness, When tightening the nut and connecting the pipe to be connected, it was not possible to judge whether or not it was completely tightened with an appropriate amount of tightening from the outside, or whether the elastic body was properly compressed. .

[0003]

Therefore, during piping work, a cap nut may not be properly tightened or an elastic body may be compressed, resulting in fluid leakage from the connecting portion.
There was a problem that the durability was reduced.

Therefore, the present invention solves the above-mentioned problems of the prior art, and it is possible to easily judge from the outside whether or not it is properly tightened or whether the elastic body is in a proper compressed state. Moreover, it is an object of the present invention to provide a pipe joint capable of preventing a tightening failure due to a variation in construction such as a flare outer diameter that occurs during piping work.

[0005]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a joint body having a tapered portion with a reduced diameter tip , a cap nut screwed to the joint body, and a cap nut .
An elastic seal member to be mounted and a tightening confirmation backup ring installed through the pipe insertion hole of the cap nut are provided, and
On the outer surface of the tapered part of the joint body,
A pipe joint whose inner surface is in close contact
The inner end face of the inner flange of the cap nut in the free state.
A gap is formed between them and the above elasticity is maintained when tightened.
The gap is absorbed by the pressing of the sealing material and the inner end surface of the inner flange
To the outer flange portion and one edge portion in the free state is the inner collar portion.
It does not protrude from the outer end surface of the
The one-side edge is pressed from the outer end surface of the inner flange by pressing the flexible sealing material.
And a cylindrical insertion portion that slightly protrudes .

[0006]

The pipe joint constructed as described above is fastened by stopping the tightening of the cap nut when the one end edge portion of the backup ring projects outward from the end face of the cap nut by a predetermined dimension during connection work. Is completed and the proper tightening force is achieved.

A backup is used to determine whether the contract has been concluded.
One end edge of the ring protrudes outward from the end face of the cap nut.
It can be judged at a glance from the outside
It

Moreover, as a backup ring,
The structure is extremely simple and easy to manufacture.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to the drawings showing embodiments.

FIG. 1 shows an example of an assembled state of a pipe joint according to the present invention. This pipe joint is made of a joint body 1 made of stainless steel or the like and a stainless steel body or the like screwed to the joint body 1. It is provided with a cap nut 2, a backup ring 3 for tightening confirmation installed through the hole 9 of the cap nut 2, and an elastic seal member 4 made of rubber or the like. Are connected.

FIG. 2 shows a disassembled state, and a cylindrical joint body 1 whose only end portion is shown has a taper portion 6 with a reduced diameter tip formed at one end edge of the joint body 1, and an outer peripheral portion thereof. A male screw 7 is formed on the.

The connected pipe 5 has a flared portion 8 flared at its end on the connection side so that the flared portion is enlarged. The inclination angle of the flared portion 8 is the outer circumference of the tapered portion 6 of the joint body 1. It is set to be approximately equal to the inclination angle of the surface.

The outer peripheral surface of the cap nut 2 is formed in a polygonal shape or a circular shape, and a hole portion 9 for inserting the connected pipe 5 through the backup ring 3 is provided on one end side of the cap nut 2. On the other end side , a female screw 10 that is screwed to the male screw 7 of the joint body 1 is formed. That is, the bag
The inner collar portion 20 is provided on the girder 2.
Hole 9 is formed.

The inner end surface 12 of the inner flange portion 20 is substantially perpendicular to the axis. In addition, the inner end face 12 and the inner collar portion 20
A corner radius R ₁ having a predetermined size is formed at a corner of the hole 9 with the inner peripheral surface .

Next, the ring-shaped elastic seal material 4 is formed so that it can be mounted on the inner peripheral surface 11 of the cap nut 2, and the inner peripheral surface of the elastic seal material 4 is a flare portion of the connected pipe 5. 8
And, it is formed so as to abut on the outer peripheral surface of the tapered portion 6 of the joint body 1.

However, the backup ring 3 integrally formed of synthetic resin or stainless steel with a predetermined thickness T.
Is colored in a prominent color such as red or blue. As shown in FIG. 3 showing the free state of the backup ring 3, the cylindrical insertion portion 13, the corner portion 14 having a predetermined curvature, and the predetermined inclination angle θ.
_{1 and} the outer collar part 15.

The insertion portion 13 is connected to the pipe 5 to be connected.
(See FIG. 1) and the hole 9 of the cap nut 2 can be interposed.

The inclination angle θ ₁ of the outer collar portion 15 is 60 ° to 8 °.
The most desirable angle is set to 3 ° --72 ° to 78 °, and the corner radius R on the outer peripheral side of the corner portion 14 is set.
The size of ₂ is set smaller than the size of the corner radius R ₁ of the cap nut 2.

Further, the backup ring 3 is internally provided in the cap nut 2 in a free state (the outer end edge of the outer flange portion 15 of the backup ring 3 is brought into contact with the inner end surface 12 of the inner flange portion 20 of the cap nut 2). At this time, the one end edge portion 16 of the backup ring 3 is set so as to be positioned inward by the dimension C from the outer end surface 17 of the cap nut 2 , and the inner flange portion 20 is
A gap 21 is formed between the end surface 12 and the outer flange portion 15.
It

Further, the backup ring 3 has a clearance as shown by a phantom line in FIG. 3 when the cap nut 2 is completely fastened to the joint body 1 with an appropriate tightening force (as shown in FIG. 1).
21 is absorbed and one edge portion 1 of the backup ring 3
6 is set to project outward from the outer end surface 17 of the cap nut 2 by a dimension D.

Then, the outer collar portion 1 of the backup ring 3
The dimension B from the outer edge of 5 to the tangent line L (in contact with the corner radius R ₂ and orthogonal to the axis M) is equal to the dimension C plus the dimension D.

In the pipe joint of this embodiment, as shown in FIG. 1, the inner peripheral surface of the flare portion 8 of the connected pipe 5 is fixed to the joint body 1 by screwing the cap nut 2 onto the joint body 1 and tightening the cap nut 2.
The outer peripheral surface of the taper portion 6 is abutted, and the outer peripheral surface of the contact portion is hermetically connected by the elastic seal material 4.
The backup ring 3 has a mark for compressing the elastic seal material 4 to an appropriate compression rate to obtain an optimum degree of sealing and a twisting prevention of the elastic seal material 4 when the cap nut 2 is screwed. Also serves as.

Now, the procedure for connecting the pipe joint constructed as described above will be described with reference to FIGS. 4 and 5.

First, as shown in FIG. 4, the insertion portion 13 of the backup ring 3 is inserted into the hole 9 of the cap nut 2, and the outer end edge of the outer flange 15 is attached to the inner end surface 12 of the cap nut 2. The cap nut 2 is brought into contact with the backup ring 3 inside.

Further, the end surface of the elastic seal material 4 is brought into contact with the backup ring 3 to mount the elastic seal material 4 in the cap nut 2.

Next, the connected pipe 5 is inserted into the hole 9 of the cap nut 2 via the backup ring 3 and flared to a desired diameter with a flaring jig to form a flared portion 8.
And the inner peripheral surface of the flared portion 8 of the connected pipe 5 is brought into contact with the outer peripheral surface of the tapered portion 6 of the joint body 1,
The female screw 10 of the cap nut 2 is screwed onto the male screw 7 of.

At this time, as shown in the figure, in the state before or during the tightening of the cap nut 2 and the backup ring 3 in the free state slightly abuts on the elastic seal member 4, the backup ring 3 is One end edge portion 16 is located inward of the outer end surface 17 of the cap nut 2 by a dimension C. One
Mari, the one end edge 16 of the backup ring 3 is a cap nut
2 does not protrude from the outer end surface 17.

Further, when the cap nut 2 is screwed with a wrench or a wrench (not shown), the outer peripheral surface of the flare portion 8 of the connected pipe 5 and a part of the outer peripheral surface of the tapered portion 6 of the joint body 1 are The inner peripheral surface of the elastic seal member 4 abuts, the elastic seal member 4 elastically deforms as the cap nut 2 is tightened, and the backup ring 3, the flare portion 8, the taper portion 6, and the inner peripheral surface 11 of the cap nut 2. In the meantime, the elastic sealing material 4 advances to a closed state.

At this time, the outer flange portion 15 and the corner portion 14 of the backup ring 3 are sandwiched between the inner end surface 12 of the cap nut 2 and the elastic seal material 4, and as the cap nut 2 is screwed,
The outer flange portion 15 is deformed along the inner end surface 12 of the cap nut 2 in a direction in which the inclination angle θ ₁ increases, and the one end edge portion 16 of the backup ring 3 projects in the arrow F direction.

[0030] Then, as shown in FIG. 5, the gap 21 is sucked
The fastening is stopped when the one end edge portion 16 of the backup ring 3 is projected outward from the outer end surface 17 of the cap nut 2 by a predetermined dimension D.

At this position, the corner portion 14 of the backup ring 3 is pressed against the base of the flare portion 8 and the cap nut 2
The outer flange portion 15 comes into close contact with the inner end surface 12 of the, the inclination angle θ ₁ becomes approximately 90 °, and the elastic sealing material 4 has an appropriate compression rate, so that it is completely closed and exhibits optimum sealing performance. Then, the fastening (connection work) is completed.

Next, FIG. 6 and FIG. 7 show that the inner end surface 12 of the cap nut 2 has a predetermined inclination angle θ ₂ with respect to the axial center.
The backup ring 3 is formed by 0 ° to 80 °
The case where the inclination angle θ ₁ of the outer flange portion 15 is approximately 90 ° is shown.

Further, as shown in FIG. 6, the backup ring 3 is in a free state (the outer end edge of the outer flange portion 15 of the backup ring 3 is brought into contact with the inner end surface 12 of the cap nut 2).
When installed in the cap nut 2, the one end edge portion 16 of the backup ring 3 is set so as to be located inward by the dimension C from the outer end face 17 of the cap nut 2, and the inner end face 12 and the outer flange are set.
A gap 21 is formed between the joint part 1 and the joint 15, and when the cap nut 2 is completely fastened to the joint body 1 with a proper tightening force, the gap 21 is absorbed and one end of the backup ring 3 is absorbed. The edge portion 16 is set so as to protrude outward from the outer end surface 17 of the cap nut 2 by a dimension D.

The connection work in this case is also the same as that of the previous embodiment shown in FIGS. 4 and 5, and from the state of FIG.
If the end edge 16 of the backup ring 3 protrudes outward from the outer end surface 17 of the cap nut 2 by a predetermined dimension D, the tightening is stopped and the tightening is stopped. It will help and the fastening will be completed.

[0035] At this time, the outer collar portion 15 and the corner portion 14 of the backup ring 3 is sandwiched between the inner end surface 12 and the elastic seal member 4 of the cap nut 2, the outer as the cap nut 2 screwed
The flange portion 15 is deformed along the inner end surface 12 having the inclination angle θ _{2 in} the direction in which the inclination angle θ ₁ increases, and the one end edge portion 16 of the backup ring 3 projects in the arrow F direction.

[0036] The present invention is not limited to the embodiments described above, a free design changes without departing from the scope of the present invention, for example, At a 3, the outer flange of the backup ring 3
The inclination angle θ ₁ of the portion 15, the dimension B, the dimension C, and the dimension D can be freely increased or decreased.

Further, in the embodiment shown in FIGS. 6 and 7, the inclination angle θ ₂ , the dimension C and the dimension D of the inner end surface 12 of the cap nut 2 are set .
You can freely increase or decrease.

[0038]

[Effect of the Invention] The present invention is constructed as described above, and thus has the following remarkable effects.

Before tightening the backup ring 3
The edge portion 16 does not protrude from the cap nut 2, and after tightening,
One end edge 16 of the backup ring 3 comes from the cap nut 2
Since it protrudes, it was properly tightened at a glance from the outside
You can easily determine whether or not. That is, backup link
One end edge portion 16 of the grip 3 projects (exposes) from the cap nut 2
If it is, it means that it is securely tightened, and
There are no scratches. The extent to absorb the gap 21 after tightening
The elastic seal material 4 presses the backup ring 3
As a result, the elastic seal material 4 has an appropriate compression rate, which is excellent.
Delivers excellent sealing performance. Variations in construction that occur during piping work, such as flare outer diameter
Even if occurs, the outer collar portion 15 of the backup ring 3 is a bag.
One end edge is closely contacted with the inner end surface 12 of the inner flange portion 20 of the nut 2.
Since 16 protrudes from the cap nut 2, an appropriate tightening amount
Alternatively, an appropriate amount of rubber compression can be recognized. Workers have less variation in construction and are skilled
Stable and stable piping work easily and reliably
Can be. The backup ring 3 has a simple structure.
Because, not a production is easy der Ri high cost.

[Brief description of drawings]

FIG. 1 is a half sectional view showing an embodiment of the present invention.

FIG. 2 is a cross-sectional view showing the same disassembled state.

FIG. 3 is a sectional view showing a free state of a backup ring.

FIG. 4 is an explanatory view showing a state before fastening the cap nut.

FIG. 5 is an explanatory view showing a state where fastening of the cap nut is completed.

FIG. 6 is an explanatory diagram showing another embodiment.

FIG. 7 is an explanatory diagram of the same.

[Explanation of symbols]

1 joint body 2 cap nut 3 backup ring 9 hole 16 one end edge 17 outer end surface

Claims (1)

(57) [Scope of utility model registration request] 1. A joint body 1 having a tapered portion 6 having a diameter-reducing tip, a cap nut 2 screwed to the joint body 1, an elastic seal member 4 attached to the cap nut 2 , and the bag. Nut 2
And a tightening confirmation backup ring 3 which is internally installed through the pipe insertion hole 9 of the fitting main body 1 and the outer surface of the tapered portion 6 of the joint body 1 by tightening the cap nut 2.
A pipe joint in which the inner surface of the flare portion 8 of the connected pipe 5 is in close contact
So, the backup ring 3 is up in the free state.
A gap is formed between the inner flange portion 20 of the pocket nut 2 and the inner end surface 12 of the inner flange portion 20.
21 and the elastic seal in the tightened state.
When the material 4 is pressed, the gap 21 is absorbed and the inner flange 20
Outer collar portion 15 that is in close contact with the end face 12, and one edge in the free state
If the portion 16 does not project from the outer end surface 17 of the inner collar portion 20,
In the tightened state, the elastic seal material 4 is pressed to
The edge portion 16 slightly projects from the outer end surface 17 of the inner collar portion 20.
And a cylindrical insertion portion 13 that has a cylindrical shape .