JPH056477Y2 - - Google Patents

Description

[Detailed explanation of the idea] [Industrial application field] The present invention relates to a pipe joint.

[Conventional technology and its problems]

BACKGROUND ART Conventionally, pipe joints such as unions and flanges used in pipes for transporting liquids such as water (including hot water) have a structure as shown in FIG. 8. That is, with the cap nut 41, the first
The member 43 and the second member 45 with the male threaded portion 44,
It was connected by tightening, but the joint surfaces 46, 46
As shown in the figure, the gasket 49 has a stepped portion and is divided into annular inner diameter side corresponding surfaces 47, 47 and outer diameter side corresponding surfaces 48, 48.
8 to prevent external leakage.
Moreover, as is clear from the figure, the inner peripheral resin coating layers A, A were applied only to the inner peripheral surfaces of the holes of the first member 43 and the second member 45.

Therefore, in FIG. 8, the annular inner diameter side corresponding surface 47,
47, the problem of "rusting" occurred.

Therefore, in order to prevent rusting, the inventors of the present invention
We considered a pipe joint as shown in Figure 9. That is, as shown in FIG. 9, a gasket 49 was interposed between the inner diameter side corresponding surfaces 47, 47. However, the cap nut 41, the first member 43, and the second member 45, which are generally cast products, have quite large dimensional errors or errors in shape such as eccentricity. Therefore, the annular inner diameter side corresponding surface 4
7. Measures must be taken to prevent the above errors from being exposed and coming into contact with liquids such as water. For this purpose, as shown in the figure, the inner diameter D of the gasket 49 is set to the inner diameter d, d of the first member 43 and second member 45.
It must be set smaller than .

In order to always prevent the annular inner diameter side corresponding surfaces 47, 47 from being exposed even if the above-mentioned errors accumulate in the assembled state of the pipe joint, the inner diameter D of the gasket 49 must be adjusted.
is considerably small, and normally the gasket 49 protrudes greatly inward of the pipe joint. Therefore, it has the disadvantage of increased pressure loss. In addition, piping that transports liquids containing powder and granules,
"Powder" and "garbage" when used in drainage piping
It's easy to get caught.

[Means for solving problems]

In order to solve the above problems of the prior art, the present invention provides a pipe fitting comprising a first member having an inner circumferential surface of a hole coated with an inner circumferential resin coating layer, a second member having an inner circumferential surface of a hole coated with an inner circumferential resin coating layer, and a gasket compressed into an annular groove having an inward opening formed by a joining surface of the first member and/or a recess provided in the joining surface of the second member when the first member and the second member are connected, wherein corners between the joining surface of the first member and the inner circumferential surface of the hole and corners between the joining surface of the second member and the inner circumferential surface of the hole are respectively formed with radius chamfers or square chamfers, and the corners of the recesses are formed with a predetermined shape, and a part or the entire joining surface including the corners is coated with an end face resin coating layer which is continuous with the inner circumferential resin coating layer on the inner circumferential surface of the hole.

[Effect]

Since each corner on the inner diameter side is chamfered, the inner peripheral resin coating layer and the end face resin coating layer are reliably continuous with a uniform thickness, and rust from the corners is reliably prevented.

Furthermore, by providing a recess at the corner of the inner diameter side corresponding surface (gasket surface), it is possible to prevent the end face resin coating layer from adhering thickly at the corner, and the gasket can be It is evenly pressed against the entire surface of the end face resin coating layer, and the sealing performance can be maintained sufficiently. Of course, the first member and the second member are
Since the end face is covered with a resin coating layer and a gasket is further crimped and interposed, rusting from this area is reliably prevented.
Further, the inner diameter of the gasket can be set large. A part of the corresponding surface on the inner diameter side is
This is because even if it is not pressed into contact with the gasket, the end face is covered with a resin coating layer and there is no fear of rust.

〔Example〕

The illustrated embodiment will be described below.

In FIG. 1, the pipe joint is composed of a first member 1, a second member 2, a cap nut 3, and a gasket 4, and the cap nut 3 has an inner flange 5 and a female threaded portion 6.
The outer surface shape is a polygonal column. The first member 1 has an outer flange 7 that is pressed against the inner flange 5 of the cap nut 3, and the inner peripheral surface 8 of the hole is coated with an inner peripheral resin coating layer A, and a tapered screw 9 is provided on the outside of the hole. It is a short cylindrical body with a The second member 2 has a male threaded portion 10 on its outer periphery that is screwed into the female threaded portion 6 of the cap nut 3, the inner peripheral surface 11 of the hole is covered with an inner peripheral resin coating layer A, and the outer side of the hole is coated with an inner peripheral resin coating layer A. is taper screw 12
It is a short cylindrical body with a FIG. 1 shows a resin coated tube 14 having a taper screw 13 screwed onto the taper screw 12. As shown in FIG.

Therefore, as shown in Figures 1 and 2, the first
On the joint surfaces 15 and 16 between the member 1 and the second member 2,
Annular inner diameter side corresponding surfaces 19, 19 and annular outer diameter side corresponding surfaces 20, 20 are defined by stepped portions 17, 18, respectively. That is, in the illustrated example, the first member 1 has a stepped portion 17 and the inner diameter side corresponding surface 19 projects, and the second member 2 has the stepped portion 18 and the outer diameter side corresponding surface 20. Let be a protrusion.

The gasket 4 is interposed between the inner diameter side corresponding surfaces 19, 19. That is, as shown in FIGS. 1 and 2, when the first member 1 and the second member 2 are connected, the stepped portion 1 is formed on the joint surface 16 of the second member 2.
An annular groove 24 having an opening in the inner diameter direction is formed by the recess 30 formed with a diameter of 8 and the corresponding inner diameter side surface 19 of the first member 1 . The gasket 4 is held in a compressed manner within this annular groove 24.

By the way, as shown in FIG.
1. Provide a rounded chamfer R of approximately 1 mm to 5 mm. Further, in the second member 2, the inner diameter side corresponding surface 19
A triangular relief part 23 is recessed in the corner part 22 formed by the outer peripheral edge part and the stepped part 18 to constitute the base material before resin coating (as shown in FIG. 2). (corresponding to the solid line), then each corner 21,
The inner diameter side corresponding surfaces 19, 19 including the holes 21, 21 and the corner portions 22 are coated with an end face resin coating layer B as shown by the imaginary line in the figure. Formed continuously with resin coating layer A.

In practice, both coating layers A and B are formed at the same time, or made of the same material and formed in separate steps. Note that, depending on the case, both coating layers A and B may be made of different materials. Also, you are free to use either powder coating or solvent coating.

Note that the present invention is not limited to the embodiments shown in FIGS. 1 and 2, and is free to make various design changes.
As shown in the figure, each corner 2 of the first member 1 and the second member 2
It is also possible to provide chamfers C... on the corners 1..., and further, in FIG. 3, a rectangular relief part 23 is formed in the corner 22 of the second member 2, but it is preferable to .

Further, as shown in FIG. 4, it is also desirable to form a relief part 23 in the corner part 22 in a semicircular or circular arc shape.

FIG. 7 is a comparative example shown to explain the unique effects of the present invention.
If the corners 1 are set at right angles and no chamfering is performed, the coating layer at the corners 21 will become extremely thin, and there is a risk of rust forming there. moreover,
If the corners 22 are left at a right angle without providing relief, a thick layer of paint will accumulate, resulting in a locally thick coating layer. The sealing performance of the gasket 4 deteriorates, and liquid leaks to the outside.
If this FIG. 7 is used as a comparative example and compared with the above embodiments of the present invention (FIGS. 1 to 4), each corner 21...
A point where a round chamfer R or a corner chamfer C is formed on the
Also, the importance of the configuration such as forming the relief portion 23 at the corner portion 22 will be recognized.

Next, FIG. 5 shows yet another embodiment, in which the structure is a so-called flange type pipe joint. That is, recesses 30 and 30 are formed in both the joining surfaces 15 and 16 of the first member 1 and the second member 2 with stepped portions 17 and 18, and the first In a connected state in which the flange portions 26 and 27 of the member 1 and the second member 2 are fastened together, the recesses 30 and 30 form an annular groove 24 that is open in the inner radial direction. Relief portions 23, 23 are formed at both inner corner portions 22, 22 of the annular groove 24, and radius chamfers R (or corner chamfers C) are formed at the corner portions 21, 21, respectively. Furthermore, a case will be illustrated in which a coating layer is formed on the entire inner surface of this annular groove 24. The gasket 4 is held within this annular groove 24.

In addition, in FIG. 6, in the connected state where the first member 1 does not have a recess and the second member 2 has a recess 30 and is fastened with the bolt-nut connection 25, one of the above An annular groove 24 is formed by the recess 30 and the end surface of the flange portion 26 of the first member 1 . A radius chamfer R (or corner chamfer C) is formed at the corner between the end face of the flange portion 26 of the first member 1 and the inner circumferential surface 8 of the hole, and the second member 2 has the same shape and structure as shown in FIG. do.

In addition, in the flange type shown in Fig. 5 or 6,
It is also preferable to form a screw hole in either one of the flange portions 26, 27 and fasten them using only bolts (not shown).

Furthermore, in any of the illustrated embodiments described above,
The resin coated pipe 14 and the pipe joint may be integrated by welding or the like, but this is included in the definition of the pipe joint of the present invention.

[Effect of idea]

With the above-described configuration, the present invention can effectively prevent rusting. In addition, the coating process becomes easy and can be performed uniformly. The inner diameter of the gasket 4 can be made substantially the same as that of the inner circumferential resin coating layers A, so that pressure loss during liquid flow does not increase. Furthermore, it is possible to prevent liquids containing powder and granules from getting caught.

[Brief explanation of the drawing]

Fig. 1 is a sectional view showing one embodiment of the present invention;
3 and 4 are enlarged sectional views showing modified examples, and FIGS. 5 and 6 are sectional views showing main parts of other embodiments, respectively. FIG. 7 is a sectional view showing a comparative example. FIGS. 8 and 9 are cross-sectional views showing conventional examples. A... Inner peripheral resin coating layer, B... Edge resin coating layer, 1... First member, 2... Second
Member, 4... Gasket, 8, 11... Hole inner peripheral surface, 15, 16... Joint surface, 21... Corner, 22
... Corner, 23 ... Recess, 24 ... Annular groove,
R...Round chamfer, C...Corner chamfer.

Claims (1)

[Claims for Utility Model Registration] A first member 1 whose inner circumferential surface 8 of the hole is coated with an inner circumferential resin coating layer A, and a second member 2 whose inner circumferential surface 11 of the hole is coated with an inner circumferential resin coating layer A. and the joint surface 15 of the first member 1 and/or the second member 2 in the connected state of the first member 1 and the second member 2.
In the pipe joint, the gasket 4 is compressed and inserted into the annular groove 24 which is open in the inner radial direction and is formed by the recess provided in the joint surface 16 of the first member 1. A corner chamfer R or a corner chamfer C is formed at a corner 21 between the joint surface 15 of the second member 2 and the inner peripheral surface 8 of the hole, and a corner 21 between the joint surface 16 of the second member 2 and the inner peripheral surface 11 of the hole. and a relief part 23 of a predetermined shape is recessed in the corner part 22 of the recess, and the joining surface 1 including each corner part 21... and corner part 22 is formed.
A pipe joint characterized in that part or all of the holes 5 and 16 are coated with an end face resin coating layer B, which is formed continuously with the inner peripheral resin coating layer A of the hole inner peripheral surfaces 8 and 11.