JPH05149487A - Pipe joint - Google Patents

Abstract

PURPOSE:To ensure that a core never fails to be installed when a pipe joint is constructed at the site by integrally forming the core and a joint main body using an elastic ring body and to accurately position the core by installing the elastic ring body in a joint main body before installing the core in the elastic ring body. CONSTITUTION:A pipe joint 10 has taper threads 14 formed on both sides of the inner surface of a joint main body 12 and a coating surface 16 formed on the central part of the inner surface. An elastic ring body is inserted into the inside of the pipe main body 12 so that it adheres to the coating surface 16. Moreover, the collar part 24 of a core 22 adheres to the adhesive surface of the elastic ring 18. The threaded part 32 of a lining pipe 20 including a steel pipe 28 and a lining layer 30 is screwed into the taper thread 14 of the pipe joint 10 to push a sealant 34 into the interior space 36 of the taper thread 14 in order to connect the pipe joint 10 to the lining pipe 20. Thus, the sealant 34 prevents the end of the lining part 20 from being corroded. This constitution ensures that the core 22 never fails to be installed and allows it to be accurately positioned.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pipe joint, and more particularly to a pipe joint having a function of protecting the pipe end of a large diameter lining pipe from corrosion.

[0002]

2. Description of the Related Art Referring to FIG. 6, a conventional pipe joint 1 includes a joint body 3 made of, for example, malleable cast iron having a screw 2 on its inner surface, and inside the joint body 3 is made of heat-resistant vinyl chloride, for example. The core 4 is injection molded. Then, the sealing material 5 is applied between the core 4 and the screw 2, and the lining pipe 6 is screwed into the pipe joint 1.

[0003]

In the above-mentioned prior art,
Since the core 4 is injection-molded, a complicated mold is required. Therefore, when the diameter of the pipe joint 1 is small, it does not matter, but the diameter of the pipe joint 1 is, for example, 1
If the size is increased to about 25 A, the die cost becomes too high and it cannot be applied.

Therefore, a pipe joint 7 as shown in FIG. 7 is known as a pipe joint for connecting large diameter pipes. This pipe joint 7 includes a joint body 3'having a screw 2'on its inner surface, and the inner surface of the joint body 3'excluding the screw 2'is coated with a resin layer 8 such as heat resistant vinyl chloride. At the time of joining, a core 9 made of, for example, heat-resistant vinyl chloride is mounted so as to cover the pipe end of the lining pipe 6 ', and the lining pipe 6'is screwed into the pipe joint 7. According to this conventional technique, a complicated mold as in the above-described conventional technique is not necessary, and the manufacturing cost can be reduced. However, since the joint body 3'and the core 9 are separate bodies in this conventional technique,
There was another problem that the core 9 might be forgotten to be attached at the time of on-site enforcement.

Therefore, a main object of the present invention is to provide a pipe joint which can reduce the manufacturing cost and can prevent forgetting to attach the core.

[0006]

According to the present invention, there is provided a metal joint body having a screw on an inner surface thereof, the inner part of which is coated with a coating, an elastic ring body adhered to the inner part, and an elastic ring body. A pipe joint including a core having an outer diameter smaller than the inner diameter dimension of the screw inner end portion.

[0007]

Operation: The inner surface of the joint body is coated with a corrosion-resistant resin except for the threaded portion, and the elastic ring body is bonded to this coated surface. Then, the core is bonded to the elastic ring body so as to be coaxial with the screw.

[0008]

According to the present invention, since a complicated mold is unnecessary, the manufacturing cost can be reduced. Moreover, since the joint body and the core are integrally formed via the elastic ring body, it is possible to prevent forgetting to attach the core. The above-mentioned objects, other objects, features and advantages of the present invention will become more apparent from the following detailed description of the embodiments with reference to the drawings.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to FIG. 1, a pipe joint 10 of this embodiment.
Includes a joint body 12 having a substantially hollow cylindrical shape made of metal such as malleable cast iron, and the inner surface of the joint body 12 is formed with taper screws 14 from both ends to the inner part.
In addition, at the center of the inner surface of the joint body 12, a taper screw 14
The coating surface 16 coated with a corrosion-resistant resin such as heat-resistant vinyl chloride is formed by slightly expanding the diameter from the rear end of the.

An elastic ring body 18 made of a rubber elastic body such as EPT (ethylene propylene terpolymer) or EPDM (ethylene propylene diene monomer) is inserted into the inside of the joint body 12 and the outer peripheral surface of the elastic ring body 18 is inserted. And the coating surface 16 are adhered. Although the outer diameter of the elastic ring body 18 is larger than the inner diameter of the taper screw 14 at the rear end portion, the elastic ring body 18 can be easily deformed (reduced in diameter), so that the insertion thereof is relatively easy.

The outer diameter of the elastic ring body 18 is substantially equal to the inner diameter of the lining pipe 20 to be connected (therefore, smaller than the inner diameter of the deep end portion of the screw 14), for example, a corrosion-resistant resin such as heat-resistant vinyl chloride. A substantially hollow cylindrical core 22 made of is bonded so as to be coaxial with the screw 14.
A collar 24 is formed on the outer periphery of the end of the core 22.
And the adhesive surface 26 formed on the elastic ring body 18 are adhered. The adhesive surface 26 is formed to be slightly wider than the collar 24 so that the position of the core 22 can be adjusted appropriately.

The lining pipe 20 connected to such a pipe joint 10 includes a steel pipe 28, and a lining layer 30 made of a corrosion-resistant resin such as heat-resistant vinyl chloride is formed on the inner surface of the steel pipe 28, and on the outer peripheral surface of the end portion. A taper screw 32 is formed on the. At the time of connection, a sealing material 34 such as a silicone sealing material is applied between the screw 14 and the core 22,
The screw 32 of the lining pipe 20 is screwed into the screw 14 of the pipe joint 10. Then, when further screwed in, the sealing material 34 is pushed into the space 36 at the back of the screw 14,
In the state shown in FIG. 2, the connection between the pipe joint 10 and the lining pipe 20 is completed, and the pipe end of the lining pipe 20 (steel pipe 28) is reliably protected by the sealing material 34. The size of the space 36 (FIG. 1) for accommodating the sealing material 34 can be appropriately changed by adjusting the bonding position of the elastic ring body 18.

According to this embodiment, a complicated mold or the like is unnecessary. Further, since the core 22 and the joint body 12 are integrally formed via the elastic ring body 18,
There is no problem of forgetting to attach the core at the time of on-site enforcement. Since the core 22 is adhered to the elastic ring body 18 after the elastic ring body 18 is adhered to the coating surface 16, the positioning accuracy of the core 22 is not affected by the positioning accuracy of the elastic ring body 18. , The core 22 can be accurately positioned.

The present invention is also applicable to the elbow 38 shown in FIG. 3, the cheese 40 shown in FIG. 5, the reducer 42 shown in FIG. it can. That is, the elbow 38 shown in FIG. 3 includes a body 12 having receptacles 44 and 46 whose axes are orthogonal to each other. Receptacles 44 and 46
The screw 14 is formed on the inner surface of the, and the coating surface 16 is formed by slightly expanding the diameter from the inner end portion of the screw 14. Then, the elastic ring body 18 is adhered to the coating surface 16, and then the core 22 is adhered to the elastic ring body 18.

The cheese 40 shown in FIG. 4 comprises a body 12 having receptacles 48 and 50 with their respective axes coincident with each other and a receptacle 52 whose axes are orthogonal to the axes of the receptacles 48 and 50. The screw 14 is formed on the inner surface of each of the receiving ports 48, 50 and 52, and the coating surface 16 is formed by slightly expanding the diameter from the inner end portion of the screw 14. Then, the elastic ring body 18 is adhered to the coating surface 16, and then the core 22 is adhered to the elastic ring body 18.

The reducer 42 shown in FIG. 5 has a large-diameter socket 5
4 and a body 12 having a small diameter receptacle 56. Receptacle 5
Screws 14 are formed on the inner surfaces of 4 and 56,
The coating surface 16 is formed by slightly expanding the diameter from the rear end portion of the. Then, elastic ring bodies 18 and 18 'having different sizes are bonded to the coating surface 16, and then the cores 22 and 22' are bonded to the elastic ring bodies 18 and 18 '.

[Brief description of drawings]

FIG. 1 is an illustrative view showing one embodiment of the present invention.

FIG. 2 is an illustrative view showing a state in which a lining pipe is connected to the embodiment of FIG.

FIG. 3 is an illustrative view showing another embodiment of the present invention.

FIG. 4 is an illustrative view showing another embodiment of the present invention.

FIG. 5 is an illustrative view showing another embodiment of the present invention.

FIG. 6 is an illustrative view showing a conventional technique.

FIG. 7 is an illustrative view showing another conventional technique.

[Explanation of symbols]

 10 ... Pipe joint 12 ... Joint body 14 ... Screw 16 ... Coating surface 18 ... Elastic ring body 22 ... Core

Claims (1)

[Claims] 1. A metal joint body having a screw on the inner surface, the inner part of the screw being coated, an elastic ring body adhered to the inner part, and the screw inner end adhered to the elastic ring body. A pipe joint comprising a core having an outer diameter smaller than the inner diameter dimension of the section.