JPH063260Y2 - Pipe fittings for lining pipes - Google Patents

Description

[Detailed Description of the Invention] [Industrial field of application] The present invention relates to a pipe joint for connecting a lining pipe, and more particularly to a pipe joint for reliably preventing damage to the pipe joint due to excessive penetration of the lining pipe. The present invention relates to a pipe joint. [Prior Art] An inner lining steel pipe provided with a synthetic resin material having high anticorrosion performance is used for water supply / hot water supply pipes, pipes for cooling / heating equipment, and the like. A socket type pipe joint 1 as shown in the drawing (cross-sectional explanatory view) is used. The pipe joint 1
Is composed of a metal outer layer tube 2 having openings at both ends and a synthetic resin inner layer tube 3 provided inside the metal outer layer tube 2. A support portion 3c extending in the radial direction is integrally formed at a substantially central portion of the outer periphery of the synthetic resin inner layer pipe 3 in the axial direction, and an engagement ring portion 3b is further formed on the tip side of the support portion 3c. The engagement ring portion 3b is joined and integrated with an annular groove portion 2c formed inside the metal outer layer tube 2. The metal outer layer tube 2
The taper screws 2a, 2a are engraved on the inner peripheral surface of each from the opening end side. On the other hand, the synthetic resin inner layer pipe 3 is formed in a straight tube, both ends 3a, 3a are extended toward the open end, between the synthetic resin inner layer pipe 3 and the metal outer layer pipe 2, An annular gap 8 is formed. The connection state of the pipe joint 1 and the lining pipe 10 configured in this way is
This is as shown in the left part of FIG. That is, there is a tape on the outer circumference on the end side.
The lining pipe 10 with the screw 11a formed thereon is the same as the metal outer layer pipe 2 described above.
-It is inserted into the annular gap 8 while being screwed with the screw 2a, and the inner surface of the synthetic resin lining layer 12 of the lining tube 10 and the outer surface of the synthetic resin inner layer tube 3 are connected so as to be in close contact with each other. It [Problems to be solved by the invention] The taper screw 2a is engraved only on the inner peripheral surface of the metal outer layer pipe 2 as shown in the right part of FIG. Inner surface 3b of the engaging ring portion 3b made of synthetic resin that is continuously provided in the inner part of the
_{No. 1} is formed with a smooth curved surface and has no thread groove.
Therefore, from the viewpoint of screw connection, a resistance structure is formed so as to prevent the lining pipe 10 from entering. However, depending on the skill level of the operator at the installation site, the lining pipe 10 may be tightened and inserted with an excessive torque of 2 to 3 times the standard tightening torque.
On the inner surface 3b ₁ of b, the thread groove is forcibly engraved by the taper screw 11a of the lining pipe 10, which causes a problem that the lining pipe 10 cannot be prevented from entering. When the lining pipe 10 is excessively inserted into the pipe joint 1 in this way, the lining pipe end surface 10a abuts against the support portion 3c and a crack C is generated in the support portion 3c, or a synthetic resin internal This causes the inconvenience of deforming the end portion 3a of the tube portion 3 inward and hindering the adhesion between the synthetic resin members. Further, an anticorrosive sealant loaded in the annular gap 8 (not shown)
However, there was a problem that it was pushed into the pipeline. Therefore, the present inventors have developed a pipe joint that does not cause damage to the pipe joint or deterioration of the joint performance even if the lining pipe is inserted by tightening due to excessive tightening torque, and the sealing agent does not leak out. The present invention has been completed for the purpose of providing it. [Means for Solving the Problem] The present invention relates to a metal outer layer pipe and a synthetic resin inner layer pipe, and a metal outer layer pipe and a synthetic resin inner layer pipe. Engage with the annular groove formed on the inner surface of the outer-layer pipe to be integrated at the back of the pipe joint, and on the opening side of the pipe joint,
In a pipe joint for an inner surface lining pipe in which an annular gap for inserting the inner surface lining pipe is formed between the metal outer layer pipe and the synthetic resin inner layer pipe, one position in the circumferential direction on the inner peripheral surface of the metal outer layer pipe Or, the stopper part is projected at a plurality of places, and the stopper part is covered by the radially extending part of the inner layer pipe made of synthetic resin, and is at least deeper than the end face of the stopper part at the missing part of the stopper part. A pipe joint for a lining pipe, characterized in that a cavity for accommodating a sealing material is formed in the pipe joint. [Operations and Examples] FIG. 1 is a sectional explanatory view showing a pipe joint which is the basis of the present invention, and corresponds to a sectional view taken along the line II of FIG. Figure 2 is the first
It is the II-II sectional view taken on the line of the figure.

The characteristic configuration of the main pipe joint shown in FIG. 1 and FIG.
A stopper 2A made of metal is formed in the inner part of the taper screw 2a so as to intermittently protrude toward the center on the inner peripheral surface side of the metal outer layer tube 2 at one or a plurality of locations in the circumferential direction (four locations in the illustrated example). There is a point. That is, the stoppers 2A are extended toward the center side to a position where they can come into contact with the end surface 10a of the inner surface lining pipe 10, and are intermittently formed at four locations in the circumferential direction in the examples of FIGS. As a result, the protruding stopper 2A and the synthetic resin supporting portion are in a state of being meshed with each other in the circumferential direction, and are firmly integrated.

As shown in the upper part of FIG. 1, on the side of the stopper 2A (on the side of the opening in the axial direction), a part 3b ₂ , 3b ₂ of the engaging ring made of synthetic resin has substantially the same inner circumference. The engaging ring portions 3b ₂ and 3b ₂ are provided so as to have a diameter, and are integrally connected to the engaging ring portion 3b ₃ continuously in the circumferential direction. The engaging ring portion is also integrated in the axial longitudinal direction at the portion 3b ₃ described above, and the portions 3b ₂ and 3b _{2 of the} engaging ring portion are not divided. The synthetic resin inner tube 3 and the engaging ring portions (3b ₂ , 3b ₃ ) are integrally formed via the support portion 3c. The both end surfaces of the missing portion (the portion where the stopper is not formed) of the stopper 2A have both end surfaces 2A of the stopper 2A.
_When the inner surface lining pipe 10 is screwed into the inner part of the taper screw 2a, the dented part is formed as the cavity part 4 for storing the anticorrosive sealant.

The state where the lining pipe 10 is connected to the pipe joint 1 having the above structure is shown on the left side of FIG. When the taper screw 11a of the lining pipe 10 is screwed and inserted into the taper screw 2a of the pipe joint 1 while the lining pipe 10 is screwed by an excessive tightening torque, the engaging ring portion 3b ₂ formed of a synthetic resin material is used. A thread groove is formed on the inner peripheral surface of the metal taper screw 11a, and the lining pipe 10 further penetrates into the inner part. However, in the pipe joint of this example, the stopper 2A protruding from the metal outer layer pipe 2 has a higher hardness than the synthetic resin member, and the taper screw 11a does not engrave the thread groove, and the stopper 2A The end surface 10a is the side surface 2 of the stopper.
The lining pipe 1 reliably abuts and receives at A ₁ .
Make sure to stop further entry of 0. Since the stopper 2A is formed integrally with the metallic outer layer tube 2,
There is no risk of cracks or the like, and it is possible to prevent the synthetic resin inner layer pipe 3 from being deformed. Therefore, even if the tightening work is performed at the connection of the lining pipe 10 and the pipe joint 1 with three times the standard tightening torque, the synthetic resin inner layer pipe 3 of the pipe joint 1 is not damaged or deformed.

The side surface 2A ₁ of the stopper 2A is provided on the opening side from the side surface of the support portion 3c, it is provided between the end face 10a of the lining pipe supporting portion 3c annular cavity 4 is formed. That is, when the lining pipe 10 and the pipe joint 1 are connected, since the anticorrosion sealant 5 is loaded in the annular gap 8 in advance, the cavity 4 functions as a reservoir for the anticorrosion sealant 5. By this, leakage of the sealant 5 can be prevented.

FIG. 3 is a sectional view showing an embodiment of the present invention in which the pipe joint having the basic structure shown in FIGS.
The stopper 2A projecting from the inner surface of the metal inner layer pipe toward the center is a radial extension portion 3 of the synthetic resin inner layer pipe.
The entire surface is covered with C ₁ and 3C ₁ , and the progress of the end surface 10a of the lining pipe 10 is stopped via the extending portion 3C ₁ . That is, since the entire surface of the stopper 2A is covered with the synthetic resin material, even if water enters this portion, the stopper 2A is not corroded and the generation of red water can be prevented.

In this embodiment, the cavity 4 is formed by locating the end surface of the support portion 3C at the missing portion where the stopper 2A is not formed, at the back side of the end surface of the stopper 2A. Thus the screwing fitted state until the lining tube 10 comes into contact with the end face 2A ₁ of the stopper 2A becomes that this cavity 4 serves as a reservoir of corrosion sealant 5, anticorrosive Sealant 5 The problem of leakage to the outside can be avoided, and more reliable and safe joining is possible.

The stopper 2A may be provided intermittently at several locations in the circumferential direction as shown in FIGS. 1 to 3, or may be provided at only one location so as to be received at one point with respect to the end surface 10a of the lining pipe. It may be supported. Further, the pipe joint is not limited to the double receiving type and may be a single receiving type, and the joint shape may be a cheese type, a cross type, a vent type or the like.

[Effect of device]

Since the present invention is configured as described above, even if the pipe joint is tightened by an excessive tightening torque,
Excessive entry of the lining pipe was reliably stopped by the stopper, and the synthetic resin member of the pipe joint was never damaged or deformed.

[Brief description of drawings]

FIG. 1 is a sectional explanatory view showing a pipe joint which is the basis of the present invention,
2 is a sectional view taken along the line II-II of FIG. 1, FIG. 3 is a sectional explanatory view showing an embodiment of the present invention, and FIG. 4 is a sectional explanatory view showing a conventional pipe joint. DESCRIPTION OF SYMBOLS 1 ... Pipe joint 2 ... Metal outer layer pipe 3 ... Synthetic resin inner layer pipe 4 ... Cavity 5 ... Corrosion preventive sealant 8 ... Annular gap 10 ... Lining pipe 11 ... Metal pipe 12 ... Synthetic resin lining pipe Department

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor, Yakuta Taku, 64 Ishizukita-machi, Sakai City, Osaka Prefecture, inside the vinyl pipe factory of Kubota Iron Works Co., Ltd. (56) Reference JP 61-31793 (JP, A) 62-886 (JP, U) Actually opened 61-128485 (JP, U)

Claims (1)

[Scope of utility model registration request] 1. A metal outer layer pipe and a synthetic resin inner layer pipe are formed on an inner surface of the metal outer layer pipe via a support portion and an engaging ring portion which extend radially from the synthetic resin inner layer pipe. Engage with the annular groove and integrate at the back of the pipe joint, on the opening side of the pipe joint,
In the pipe joint for the inner surface lining pipe, which forms an annular gap for inserting the inner surface lining pipe between the metal outer layer pipe and the synthetic resin inner layer pipe, in the circumferential direction of the inner peripheral surface of the metal outer layer pipe A stopper part is provided at one or more places, and the stopper part is covered by a radially extending part of the synthetic resin inner layer pipe, and the stopper part is provided at least at the missing part of the stopper part. A pipe joint for a lining pipe, characterized in that a cavity for accumulating the seal material is formed on the inner side of the end face of the.