JPH0240916B2 - BOSHOKUKANTSUGITE - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a corrosion-resistant pipe joint suitable for use in water piping.

(Prior art) Conventionally, as corrosion-resistant pipe joints, for example,
As described in Japanese Patent No. 16215 (see Fig. 7), it is fitted into an annular recess 3 formed at the center inner periphery of a socket body 1 made of vinyl chloride and a cylindrical body 2 made of corrosion-resistant aluminum. movement is prevented, and its inner peripheral surface is formed into tapered surfaces 4, 4 whose apertures widen as they go from the annular projection 5 formed on the central inner periphery toward the end of the mouth. It has been proposed that the PVC pipe portion of the pipe fit tightly together.

(Problems to be Solved by the Invention) However, in the conventional socket body 1 as described above, the fitting between the socket body 1 and the double pipe is not sufficient, and the internal fluid seeps into the cylinder body 2, causing the cylinder to leak. A drawback was that the body 2 could not be sufficiently protected against corrosion.

(Means for Solving the Problems) The present invention has been made for the purpose of eliminating the conventional drawbacks as described above, and its gist is that a female threaded portion is provided on the inner circumferential surface of the end portion, and A metal pipe joint main body having a concave groove along the circumferential direction on the inner circumferential surface of the deep part is provided with a female thread part continuous to the female thread part on the inner circumferential surface of the end part, and the inner circumferential surface of the deep part The present invention relates to a corrosion-resistant pipe joint in which a cylindrical body made of synthetic resin is fitted with a cylindrical body provided with protrusions along the circumferential direction.

(Function) In the corrosion-resistant pipe joint of the present invention, a sealing material such as packing is compressed between the convex strip provided along the circumferential direction on the inner peripheral surface of the deep part and the end face of the inner-coated steel pipe to be connected. Since it can be mediated by
A sealing structure can be provided on at least two sides, including the screwing surface between the female threaded portion of the synthetic resin cylindrical body and the female threaded portion of the internally coated steel tube, and the close contact surface between the packing and the end surface of the internally coated steel tube.

(Examples) Hereinafter, the present invention will be explained with reference to examples shown in the drawings.
FIG. 1 is a sectional view showing one embodiment of the present invention.
Reference numeral 11 denotes a metal pipe joint body, which is provided with internal threads 111, 111 on the inner circumferential surface of both ends thereof, and a wide groove 112 is provided along the circumferential direction on the inner circumferential surface of the deep part thereof.

Reference numeral 12 is a cylindrical body made of synthetic resin, the outer circumferential surface of which has a shape that corresponds to the groove 112 of the metal pipe joint body 11, and female threads 121, 121 on the inner circumferential surface of both ends.
is the female threaded portion 111, 11 of the metal pipe joint body 11.
1, and a protruding strip 122 is provided along the circumferential direction on the inner circumferential surface of the deep part thereof.

A synthetic resin cylindrical body 12 is fitted into a groove 112 of a metal pipe joint body 11 by injection molding to form a corrosion-resistant pipe joint.

FIG. 2 is a sectional view showing how the corrosion-resistant pipe joint shown in FIG. 1 is used. Since a convex strip 122 is provided along the circumferential direction on the deep inner circumferential surface of the synthetic resin cylindrical body 12, the flanged short cylindrical body 14 and the packing 15 are provided between the end face of the internally coated steel pipe 13 to be connected. It can be tightened through the pipe, making it possible to make a connection with excellent watertightness.

FIG. 3 is a sectional view showing a second embodiment of the present invention.

The protruding stripes 122' of the synthetic resin cylindrical body 12' are provided with 123' and 12' extending toward the end of the metal pipe joint body 11'.
3' is provided integrally.

If, as in this embodiment, protruding pieces 123', 123' toward the end of the metal pipe joint body 11' are integrally provided on the protruding strip 122' of the synthetic resin cylindrical body 12', When connecting inner-coated steel pipes through packing, a short flanged tube 1 as shown in Fig. 2 is used.
4 is unnecessary, and the connection can be made with the core exposed than when using the short flanged tube 14, which is preferable.

FIG. 4 is a sectional view showing a third embodiment of the present invention.

FIG. 3 shows protruding pieces 123', 12 on the convex strip 122' of the synthetic resin cylindrical body 12' as in the illustrated embodiment.
3' is not integrally provided, and the metal pipe joint body 1 is attached to the protrusion 122'' of the synthetic resin cylindrical body 12''.
A short cylindrical body 20 having projecting pieces 201, 201 toward the 1'' end is provided separately.

If the short cylindrical body 20 having the protruding pieces 201, 201 is provided separately as in this embodiment, if the protruding pieces 201, 201 are damaged, only the short cylindrical body 20 needs to be replaced. suitable.

FIG. 5 is a sectional view showing a fourth embodiment of the present invention.

Synthetic resin cylindrical body 21 and female threaded portions 211, 21
A groove 2 is formed along the circumferential direction between the groove 1 and the protrusion 212.
13,213 are provided.

If grooves 213, 213 are provided along the circumferential direction between the internally threaded portions 211, 211 of the synthetic resin cylindrical body 21 and the convex strips 212 as in this embodiment, FIG. As shown, when the flanged short cylindrical body 14 and the packing 15 are interposed between the end face of the inner-coated steel pipe 13 to be connected and tightened, even if there are variations in the threads, the packing 14 does not fit into the groove 213.
It deforms in such a way that it bulges inward, making it possible to make a connection with excellent watertightness.

(Effects of the Invention) By having the above-described structure of the corrosion-resistant pipe joint of the present invention, when the inner-coated steel pipe is screwed into the female thread of the synthetic resin cylindrical body, the thread is sealed and internal fluid leaks. This prevents the internal fluid from seeping into the pipe fitting body and causing corrosion.

In addition, since a protruding strip is provided along the circumferential direction on the deep inner peripheral surface of the synthetic resin cylindrical body, packing or the like is interposed in a compressed state between the protruding strip and the end face of the internally coated steel pipe. As a result, not only the threaded portion but also the end face of the steel pipe is sealed, making it possible to more completely prevent internal fluid from seeping out.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view showing one embodiment of the present invention, and FIG.
The figure is a sectional view illustrating how the embodiment of FIG. 1 is used, FIGS. 3 to 5 are sectional views each showing other embodiments of the present invention, and FIG. FIG. 7 is a cross-sectional view illustrating the conventional method. 11, 11', 11''...Metal pipe joint body, 1
2, 12', 12''...Synthetic resin cylindrical body, 11
1,211...Female thread part, 112...Concave groove, 12
1...Female thread part, 122, 122, 122', 2
12″...Convex strip.

Claims (1)

[Claims] 1 A female threaded portion is provided on the inner circumferential surface of the end portion, and a groove is provided on the inner circumferential surface of the end portion of the main body of the metal pipe fitting body, and the groove is provided with a groove along the circumferential direction on the inner circumferential surface of the end portion. A corrosion-resistant pipe joint in which a synthetic resin cylindrical body is fitted, which is provided with a female threaded part and has protrusions along the circumferential direction on the inner peripheral surface of the inner part.