JPH10132159A - Pipe fitting and method of manufacturing the same - Google Patents

Abstract

(57) [Summary] An object of the present invention is to provide a pipe joint capable of more reliably preventing pipe end corrosion and a method of manufacturing the same. A metal joint body having a pipe connection part at both ends and a resin layer provided along an inner wall surface of the joint body excluding the pipe connection part, and a resin core provided at one of the pipe connection parts At the end of the resin layer of the joint where the resin core is not provided, a reinforcing ring made of a rigid material having corrosion resistance is fitted inside the resin layer, and the outer peripheral surface of the reinforcing ring is attached to the inner peripheral surface of the resin layer. The resin layer and the joint body were brought into close contact with each other in a watertight manner by pressure contact.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a pipe joint and a method for manufacturing the same.

[0002]

2. Description of the Related Art A pipe joint for water supply or hot water supply has a plurality of pipe joints in order to prevent corrosion of a pipe end of a pipe to be connected, and a metal joint body and at least a pipe joint are provided. Except for the resin layer provided along the inner wall surface of the joint body excluding, and the flow of fluid flowing inside the pipe to the pipe end face whose outer peripheral surface is in close contact with the inner peripheral surface of the pipe connected to this pipe connection part Joint (tube end corrosion protection joint) provided with a tubular resin core for preventing cracks
In general, for example, a threaded pipe end anticorrosion joint for water supply is manufactured by the Iron Pipe Fitting Association (JPF) MP003.
For example, a screw-in type pipe end anticorrosion joint for hot water supply has been standardized as MP005 of the Iron Pipe Joint Association (JPF), and the pipe end anticorrosion joint has also been classified by the Water and Steel Pipe Association (WSP).

That is, as a conventional pipe joint, as shown in FIG. 3, a resin core 104 integrally formed with a resin layer 103 is provided on all of the pipe connecting portions 102 provided on a metal joint body 101. As shown in FIG. 4, the resin layer 2 is provided on one pipe connection portion 202 of the fitting body 201.
03 has a resin core 204 integrally formed thereon, and the other pipe connection portion 205 does not include the resin core 204. As shown in FIG. A core 303 is provided, and this resin core 303 has a cylindrical resin core 303 formed at one end.
And a pipe joint 300 formed by internally fitting an end portion of the resin layer 306.

However, among the above-mentioned conventional pipe joints, the pipe joints 200 and 300 having a structure as shown in FIGS. 4 and 5 have some problems in terms of pipe end corrosion resistance. That is, the pipe joint 20
In the case of 0, on the side where the resin core 204 is provided, when the pipe 206 is connected to the pipe connection part 202, the end face of the resin layer 203 is completely isolated from the fluid flowing through the pipe by the pipe, Since the resin core 204 is not provided on the pipe connection part 205 side, the end face of the resin layer 203 is exposed to the fluid flowing through the pipe depending on the degree of screwing of the pipe into the pipe connection part 205, and the resin Layer 20
There is a possibility that the fluid may seep into between the joint body 3 and the joint body 201 and penetrate to the opposite side of the pipe connection part 202 to corrode the pipe end of the pipe 206 connected to the pipe connection part 202 from the outside.

On the other hand, in the case of the pipe joint 300, the resin layer 306
The fluid flowing in the pipe from the fitting interface between the pipe connecting part 30 and the fitting cylindrical part 305 enters the end face side of the resin layer 306, and the
There is a possibility that the pipe end of the pipe connected to 2 is corroded from the outside. Therefore, in any of the pipe joints, this phenomenon is prevented by bonding the joint body and the resin layer with an adhesive, but the present situation has not reached a complete solution.

[0006]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has as its object to provide a pipe joint capable of more reliably preventing pipe end corrosion and a method of manufacturing the same.

[0007]

In order to achieve such an object, a pipe joint according to the first aspect of the present invention (hereinafter referred to as a "joint of the first aspect") comprises a plurality of pipe joints. In a pipe joint including a metal joint body having a resin layer provided along the inner wall surface of the joint body excluding at least the pipe connection portion, a reinforcing ring made of a corrosion-resistant rigid material is provided inside the resin layer. The reinforcing ring is inserted and the outer peripheral surface of the reinforcing ring is pressed against the inner peripheral surface of the resin layer so as to urge the resin layer toward the joint body.

In the joint according to the first aspect, it is preferable that the reinforcing ring is pressed against the inner peripheral surface of the end of the resin layer.

[0009] The method of manufacturing a pipe joint according to the invention of claim 3 (hereinafter referred to as "the manufacturing method of claim 3") is to provide a ring made of a corrosion-resistant metal material having an outer diameter smaller than the inner diameter of the resin layer. The reinforcing ring is formed by inserting the ring inside the resin layer and expanding the ring at a predetermined position until the outer peripheral surface of the ring is pressed against the inner peripheral surface of the resin layer with a pressure for urging the resin layer toward the joint body. I made it.

[0010] The pipe joint according to the invention of claim 4 (hereinafter referred to as "joint of claim 4") is a metal joint body having a plurality of pipe connection parts and a joint body excluding the pipe connection part. A resin layer provided along the inner wall surface, and a cylindrical shape whose outer peripheral surface is in close contact with the inner peripheral surface of the pipe connected to the pipe connection portion to prevent the fluid flowing inside the pipe from flowing around the pipe end face of the connection pipe. And a fitting core portion formed at the other end of the resin core forming member having a tubular resin core portion formed at one end thereof, by fitting the fitting core portion inside the end portion of the resin layer. In the formed pipe joint, a reinforcing ring made of a corrosion-resistant rigid material is inserted inside the fitting tube portion, and the outer peripheral surface of the reinforcing ring attaches the fitting tube portion to the resin layer side. It is configured to be pressed against the inner peripheral surface of the fitting cylindrical portion so as to urge it.

According to a fifth aspect of the present invention, there is provided a method of manufacturing a pipe joint (hereinafter referred to as a “method of manufacturing a fifth aspect”) made of a corrosion-resistant metal material having an outer diameter smaller than an inner diameter of a fitting cylinder. While the ring is inserted inside the fitting tube portion, and the fitting tube portion is fitted inside the resin layer, the ring is fitted with a pressure such that the outer peripheral surface urges the fitting tube portion toward the resin layer side. The reinforcing ring was formed by expanding the diameter until it came into pressure contact with the inner peripheral surface of the tube portion.

In the structure of the present invention, the joint body is not particularly limited, and may be made of a copper alloy such as stainless steel or bronze casting. The resin forming the resin layer is not particularly limited. For example, in the case of hot water supply, heat-resistant hard polyvinyl chloride, cross-linked polyethylene,
Polybutene and the like, and for water supply, hard polyvinyl chloride, polyethylene and the like.

The corrosion-resistant metal material is not particularly limited, and examples thereof include stainless steel and copper alloy.
The wire diameter of the reinforcing ring and the degree of diameter expansion of the ring are appropriately examined in consideration of the material and thickness of the resin constituting the resin layer, and are generally set to an extent that the thickness of the resin layer can be compressed by 10 to 30%. I just need to gain power.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below.
This will be described in detail with reference to the drawings. FIG. 1 shows an embodiment of the pipe joint of claim 1.

As shown in FIG. 1, the pipe joint 1a is of an elbow type and includes a joint body 2, a resin layer 3, a resin core 4, and a reinforcing ring 5. The joint body 2 is in the form of an elbow made of bronze casting, and is provided with pipe connection portions 21 and 22 provided with screws on the inner peripheral surface at both ends.

The resin layer 3 is provided so as to cover the inner peripheral surface of the joint main body 2 except for the pipe connection portions 21 and 22. The resin core 4 has a cylindrical shape whose outer peripheral surface is in close contact with the inner peripheral surface of the pipe to be connected, and is provided on one of the pipe connecting portions 21 by integral molding with the resin layer 3.

The reinforcing ring 5 is formed by connecting a ring 51 having an outer diameter smaller than the inner diameter of the resin layer 3 made of a corrosion-resistant metal material to the pipe connecting portion 2 on the side where the resin core 4 is not provided.
After being inserted into the inside of the end 31 of the resin layer 3 on the second side, it is fitted inside the resin layer 3 by mechanically expanding the diameter, and the outer peripheral surface thereof forms the inner periphery of the end 31 of the resin layer 3. The surface is urged toward the joint body 2.

As described above, the pipe joint 1a is connected to the inner peripheral surface of the end portion 31 of the resin layer 3 at the pipe connection portion 22 on the side of the resin layer 3 where the resin core 4 is not provided by the reinforcing ring 5. Since the resin layer 3 is urged toward the main body 2 and the resin layer 3 and the joint main body 2 are surely and tightly adhered to each other at the interface, the pipe is screwed into the pipe connection portion 22 on the side where the resin core 4 is not provided. Even if there is a shortage, the fluid in the pipe does not flow from the end 31 of the resin layer 3 through the space between the resin layer 3 and the joint body 2 to the opposite pipe connection portion 21 side.

Therefore, the pipe connecting portion 21 on the resin core 4 side
The pipes connected to it will never be corroded.

In addition, the pipe joint 1a includes a ring 51 having a reinforcing ring 5 having an outer diameter smaller than the inner diameter of the resin layer 3 and a resin layer 3 on the side of the pipe connecting portion 22 on which the resin core 4 is not provided. After being inserted inside the end of the pipe joint, the pipe joint 1a according to the present invention can be easily provided by being provided so as to be pressed against the resin layer 3 by mechanically expanding the diameter.
It can be. That is, the applicable range is very wide and it can be manufactured at low cost.

The joint according to claim 1 is not limited to the above embodiment. For example, in the above embodiment,
The reinforcing ring 5 is provided at the end 31 on the side of the pipe connection portion 22 where the resin core 4 is not provided.
If it is a part between 1 and the pipe connection part 22, it does not have to be the end part 31. Further, the number of the reinforcing rings 5 may be provided not only at one place but also at two or more places.

Further, in the above embodiment, the joint 1a
Has an elbow type, but may be a socket type, a cheese type or a valve.

FIG. 2 shows an embodiment of the joint according to the fourth aspect. As shown in FIG. 2, this pipe joint 1b
The joint body 6 includes a resin layer 7, resin cores 81, 81, and reinforcing rings 9, 9.

The joint body 6 is in the form of an elbow made of bronze casting, and is provided with pipe connection portions 61, 61 each provided with a screw on the inner peripheral surface at both ends. The resin layer 7 includes a pipe connection portion 61,
It is provided so as to cover the inner peripheral surface of the joint main body 6 except 61.

The resin core 81 includes a resin core 81 on one side and a fitting cylindrical portion 82 on the other side.
Are respectively provided inside the two pipe connecting portions 61 of the joint body 6, and the fitting cylindrical portions 82 are internally fitted into both ends of the resin layer 7 to be integrally provided in the both pipe connecting portions 61. I have. After the resin core 81 is integrally provided in the pipe connecting portion 61 as described above, the reinforcing ring 9 has an outer diameter smaller than the minimum diameter of the resin core forming member 8 formed of a corrosion-resistant metal material. The ring 91 is formed by inserting the ring 91 into the resin core forming member 8 from the resin core 81 side and mechanically expanding the diameter at the fitting cylinder portion 82, and the outer peripheral surface of the ring 91 forms the inside of the fitting cylinder portion 82. It presses against the peripheral surface and urges the fitting cylindrical portion 82 toward the resin layer 7.

As described above, the fitting tube portion 82 of the pipe joint 1b is urged toward the resin layer 7 by the reinforcing ring 9,
Since the fitting cylindrical portion 82 and the resin layer 7 are surely and tightly adhered to each other at the interface, the fluid flowing through the pipes never flows into the pipe connecting portions 61, 61. Further, the reinforcing ring 9 can be mounted simply by inserting the ring 91 and expanding the diameter in the same manner as in the pipe joint 1a, so that it is possible to manufacture easily and inexpensively.

The joint according to claim 4 is not limited to the above embodiment. For example, in the above-described pipe joint 1b,
Although the resin core 81 is provided on both pipe connecting portions 61 by the resin core forming member 8, a structure in which the resin core is provided only on one of the pipe connecting portions similarly to the pipe joint 1a may be employed. In the case of such a structure, it is preferable that the reinforcing ring is provided also at the end of the resin layer on the pipe connection portion side where no resin core is provided.

[0028]

As described above, the joints according to the first, second, and fourth aspects of the present invention enable more reliable pipe end corrosion protection. Further, according to the manufacturing method of the third and fifth aspects, the joint of the first, second or fourth aspect can be manufactured easily and at low cost.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an embodiment of a joint according to claim 1;

FIG. 2 is a sectional view showing an embodiment of the joint of claim 4;

FIG. 3 is a sectional view showing an example of a conventional pipe joint.

FIG. 4 is a sectional view showing another example of another conventional pipe joint.

FIG. 5 is a sectional view showing another example of another conventional pipe joint.

[Explanation of symbols]

 1a pipe joint 1b pipe joint 2 joint body 21 pipe connection part 22 pipe connection part 3 resin layer 4 resin core 5 reinforcing ring 51 ring 6 joint body 61 pipe connection part 7 resin layer 8 resin core forming member 81 resin core 82 fitting cylinder Part 9 Reinforcement ring 91 Ring

Claims (5)

[Claims] 1. A pipe joint comprising a metal joint body having a plurality of pipe joints and a resin layer provided along an inner wall surface of the joint body excluding at least the pipe joints, wherein the rigid material has corrosion resistance. Is inserted inside the resin layer, and the outer peripheral surface of the reinforcing ring is pressed against the inner peripheral surface of the resin layer so as to urge the resin layer toward the joint body. Pipe fittings. 2. The pipe joint according to claim 1, wherein the reinforcing ring is provided at an end of the resin layer. 3. A ring made of a corrosion-resistant metal material having an outer diameter smaller than the inner diameter of the resin layer is inserted into the resin layer, and the outer peripheral surface of the ring urges the resin layer toward the joint body at a predetermined position. The method for manufacturing a pipe joint according to claim 1, wherein the reinforcing ring is formed by expanding the diameter until the inner surface of the resin layer is pressed against the inner surface of the resin layer by pressure. 4. A joint body made of metal having a plurality of pipe connections, a resin layer provided along an inner wall surface of the joint body excluding the pipe connections, and an inner periphery of a pipe connected to the pipe connections. A resin core having a cylindrical resin core formed at one end with a cylindrical resin core having an outer peripheral surface in close contact with the surface and preventing the fluid flowing in the pipe from flowing around the pipe end surface of the connection pipe. In a pipe joint formed by fitting a fitting tube portion formed at the other end of the core forming member into an end portion of the resin layer, a reinforcing ring made of a corrosion-resistant rigid material is provided. A pipe joint which is inserted inside a portion and which has an outer peripheral surface of the reinforcing ring pressed against an inner peripheral surface of the fitting cylindrical portion so as to urge the fitting cylindrical portion toward the resin layer. 5. A state in which a ring made of a corrosion-resistant metal material having an outer diameter smaller than the inner diameter of the fitting cylinder is inserted inside the fitting cylinder, and the fitting cylinder is fitted inside the resin layer. The pipe joint according to claim 4, wherein the reinforcing ring is formed by expanding the diameter of the ring until the outer peripheral surface thereof is pressed against the inner peripheral surface of the fitting cylindrical portion by a pressure for urging the fitting cylindrical portion toward the resin layer. Manufacturing method.