JPS6052347B2 - pipe fittings - Google Patents

Description

[Detailed description of the invention] The present invention relates to a pipe joint.

Conventionally, as pipe joints, for example, Japanese Patent Publication No. 51-1621
As described in Publication No. 5 (see Fig. 3), it consists of a socket body 1' made of vinyl chloride and a cylindrical body 2' made of corrosion-resistant aluminum. It fits into an annular recess 3' formed on the periphery to prevent its axial movement, and its inner peripheral surface extends from the annular protrusion 5' formed on the central inner periphery toward the mouth end. Accordingly, it has been proposed that the tapered surfaces 4', 4' are formed so that the diameter increases, and the double-ply vinyl chloride pipe portion is tightly fitted onto these surfaces.

However, in the conventional socket body 1' as described above, the fitting between the socket body 1' and the double pipe is insufficient, and the internal fluid seeps into the end face of the double pipe and the cylindrical body 2'. The disadvantage was that the end face and cylindrical body of the cylindrical body could not be sufficiently protected from corrosion. The present invention solves the conventional drawbacks as described above.1--
pPJ, ↓MuJ-Ne^ise9^P ιSmall 1f5E is a metal pipe fitting body with a female thread on the inner circumferential surface of the end and a recess along the circumferential direction on the inner circumferential surface of the deep part. A cylindrical body made of synthetic resin having a female threaded portion on the inner circumferential surface of the end portion is fitted in the inner part, and a flange having a flange portion having a male threaded portion on the outer circumferential surface of the cylindrical body made of synthetic resin. There are pipe joints in which short cylindrical bodies are screwed together.

Hereinafter, the present invention will be explained with reference to embodiments of the drawings.

FIG. 1 is a sectional view showing one embodiment of the present invention. Reference numeral 1 denotes an elbow-type metal pipe joint body, which is provided with internal threads 11, 11 on the inner circumferential surface of both ends, and a wide recess 12 along the circumferential direction on the inner circumferential surface of the deep part thereof.

Reference numeral 2 is a cylindrical body made of synthetic resin, the outer circumferential surface of which has a shape that corresponds to the recess 12 of the metal pipe fitting body 1, and female threaded portions 21, 21 on the inner circumferential surfaces of both ends are female threaded portions of the metal pipe fitting body. 1
1 and 11, and a convex portion 22'' is provided in the inner part along the circumferential direction.

A synthetic resin cylindrical body 2 is fitted into a recess 12 of a metal pipe joint body 1 by injection molding.

Reference numerals 3, 3 are short cylindrical bodies with flanges, and flanges 32, 32 are provided outside one end of the short cylindrical parts 31, 31, and a synthetic resin cylindrical body 2 is provided on the outer peripheral surface of the flanges 32, 32. Male threaded parts 321, 321 are provided which are screwed into the female threaded parts 21, 21 of the short cylindrical part 31.
, 31 are provided with protrusions 311, 311 along the circumferential direction, and flanges 32, 32 of the short cylinder parts 31, 31 are provided. 312,
312... are provided.

The male threaded portions of the flanges 32, 32 of the short flanged cylindrical bodies 3, 3 are screwed into the female threaded portions 21, 21 of the synthetic resin cylindrical body 2 fitted into the recess 12 of the metal pipe joint body 1. Short cylindrical body with flange 3
, 3 are installed inside the pipe joint.

FIG. 2 is a sectional view illustrating one mode of use of the pipe joint of the embodiment shown in FIG. 1.

Reference numerals 4 and 4 refer to internally coated steel pipes, in which corrosion-resistant inner coating layers 42, 42 are provided on the inner surfaces of the steel pipes 41, 41.
, 41 are provided with male threaded portions 411, 411 on the outer circumferential surfaces of the ends thereof.

The male threaded portions 4 of the internally coated steel pipes 4, 4 are attached to the female threaded portions 11, 11 of the metal pipe fitting main body 1 of the pipe joint and the female threaded portions 21, 21 of the synthetic resin cylindrical body 2 provided so as to be continuous therewith.
11, 411, the short cylindrical portion 3 of the flanged short cylindrical bodies 3, 3 will be attached to the inner surface coating layers 42, 42 of the inner surface coated steel pipes 4, 4.
The protrusions 311, 311 provided on the outer circumferential surfaces of the parts 1, 31 come into contact with each other, and the internal fluid is sheeted at this part, and the synthetic resin cylindrical body 2 and the flanged short cylindrical bodies 3, 3 are screwed together. This prevents corrosion from seeping into the end surfaces of the inner-coated steel pipes 4, 4 and the metal pipe joint body 1.

In addition, in order to more reliably seal between the internally coated steel pipes 4, 4 and the flanged short cylinders 3, 3, an annular packing (not shown) is attached to the short cylinder portion 31 of the flanged short cylinders 3, 3. , 31, and when the inner-coated steel pipes 4, 4 are screwed together to the pipe joint, the annular packing is attached to the end surfaces of the inner-coated steel pipes 4, 4 and the flanged short cylindrical bodies 3, 3. It can also be held between the sides of the collar parts 32, 32.

In the embodiment described above, the short cylindrical portion 3 of the flanged short cylindrical bodies 3, 3
Although a case has been described in which the protrusions 311, 311 are provided on the outer peripheral surfaces of the parts 1, 31, the protrusions 311, 311 are not necessarily essential.

If the protrusions 311, 311 are not provided, when the internally coated pipe is connected to the pipe joint, the outer peripheral surface of the short cylindrical part of the flanged short cylinder will come into contact with the inner peripheral surface of the internally coated layer of the internally coated steel pipe. A seal is created between the two. Again, as described above, annular packing can be used to complete the seal as appropriate.
As described above, in the pipe joint of the present invention, a synthetic resin cylindrical body having a female threaded portion on the inner circumferential surface of the end is fitted into a recess in the deep part of the metal pipe joint body, and the synthetic resin cylinder A short cylindrical body with a flange, which has a flange with a male thread on the outer circumferential surface, is screwed onto the shaped body, so when an internally coated steel pipe is connected to this pipe joint, the inner coating layer of the internally coated steel pipe and Internal fluid is sealed between the short cylindrical part of the flanged short cylindrical body and between the threaded joint between the synthetic resin cylindrical body and the flanged short cylindrical body, and the end face of the inner-coated steel pipe and the metal pipe joint are sealed. The internal fluid does not seep into the main body, and corrosion protection can be achieved satisfactorily.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing an embodiment of the present invention, FIG. 2 is a sectional view explaining one usage mode of the embodiment of FIG. 1, and FIG. 3 is a sectional view showing a conventional one. Explanation of symbols, 1...Metal pipe fitting body, 2...
... Synthetic resin cylindrical body, 3... Short cylindrical body with flange,
4... Internally coated steel pipe, 11... Female threaded portion, 12... Concave portion, 21... Female threaded portion,
22...Convex portion, 31...Short tube portion, 32...
...Trim, 311...Protrusion, 321...
Male thread part.

Claims (1)

[Scope of Claims] 1. A female threaded portion is provided on the inner circumferential surface of the end portion, and a female threaded portion is provided on the inner circumferential surface of the end portion in the deep part of the metal pipe fitting main body, which is provided with a recessed portion along the circumferential direction on the inner circumferential surface of the deep portion. A pipe in which a cylindrical body made of synthetic resin with a cylindrical part is fitted into the cylindrical body made of synthetic resin, and a short cylindrical body with a flange, which has a cylindrical body with a flange provided with a male thread on the outer peripheral surface, is screwed into the cylindrical body made of synthetic resin. Fittings. 2. The pipe joint according to claim 1, wherein the flanged short cylindrical body is provided with protrusions along the circumferential direction on the outer peripheral surface of the short cylindrical portion.