JPH06185686A - Pipe joint for connecting branch pipe - Google Patents

Abstract

PURPOSE:To provide a pipe joint which can be attached with a high fastening strength, irrespective variations in the diameter and wall thickness of a main pipe and which can surely prevent external leakage of fluid from the pipe. CONSTITUTION:An insertion part 5B of a pipe connecting pedestal 5 for connecting a branch pipe is screwed into a thread hole 10 of a main pipe 1 so that a saddle part 5A of the pedestal 5 is set on the main pipe 1, and a rectangular head 19A of a manual tool 19 is fitted in a rectangular cross-sectional shape through-hole 8c formed in a cylindrical support member 8 which is temporarily retained by being screwed in a thread hole 15 in the insertion part 5B for attaching the cylindrical support member, and is then rotated. Accordingly, the support member 8 is advanced so that the a cylindrical seal member 7 and a back-up ring 18 which are loosely fitted in a lower flange part 8B of the cylindrical support member 8 are made into press-contact with a tapered surface 16 at the lower end of the insertion part 5B so as to be deformed, thereby the cylindrical seal member 7 is made into close contact with the tapered surface 16 and the inner surface of a lining layer 9, spanning therebetween.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a branch pipe connecting joint for connecting a branch pipe to a main pipe such as a gas pipe.

[0002]

2. Description of the Related Art Conventionally, in the connection of a branch pipe (not shown) to a main pipe 1 shown in FIG. 6, a screw hole 2 is first provided at a predetermined position of the main pipe 1, and then a branch pipe is inserted into the screw hole 2. The male threaded portion 3A formed on the lower portion of the connecting pipe joint 3 is screwed to connect the pipe joint 3 to the main pipe, and the branch pipe portion 3B projecting from the side surface of the connected pipe joint 3 is branched. Is done by connecting.

However, the conventional pipe joint 3 for connecting a branch pipe described above.
Then, as the diameter of the main pipe 1 becomes smaller, the curvature of the pipe becomes smaller, so that the number of effective threads of the screw hole 2 becomes smaller and the amount of screw engagement with the male screw portion 3A becomes smaller. Therefore, a large fastening strength cannot be ensured with a small-diameter main pipe 1, and it is difficult to securely attach the pipe joint 3, and a fluid such as gas passing through the main pipe 1 is not screwed from a threaded portion. There is also a risk of leakage to the outside.

In order to prolong the life of the main pipe 1, a technique has been developed in which a resin pipe such as hard vinyl chloride is attached to the inner surface of the main pipe 1 to form a lining layer. The fluid passing through the inside of the main pipe 1 may enter between 1 and the lining layer and may leak through the gap between the main pipe 1 and the lining layer 9.

[0005]

The problem to be solved is that the fastening strength varies due to fluctuations in the pipe diameter and wall thickness of the main pipe, and a large fastening strength cannot be ensured with a small-diameter main pipe. It is difficult to securely attach the pipe, and there is a risk that fluid such as gas passing through the main pipe may leak to the outside from the screwing portion with a small screwing amount.

[0006]

According to the present invention, there is provided a saddle portion for straddling the main pipe and an insertion portion which is connected to the saddle portion and which is fitted into a through hole formed in the main pipe and inserted into the main pipe. Then, the branch pipe connecting screw hole and the tubular support mounting screw hole are concentrically communicated from the saddle part side and formed penetratingly, and the distal end portion of the insertion portion is formed on the taper surface for connecting the branch pipe. A pedestal and a cylindrical support having a male screw portion that is screwed into the cylindrical support mounting screw hole, a flange portion formed on the outer periphery of the lower end portion, and a rectangular cross-sectional through hole that is concentric with the male screw portion. A tubular seal member loosely fitted on the collar portion of the tubular support, the insertion portion of the pedestal being fitted in the through hole of the main pipe, and the saddle portion being saddle-mounted on the main pipe. In this state, the tubular support temporarily fixed to the tubular support attachment screw hole of the pedestal is rotated and screwed to move the tubular seal. It is characterized in that the material is pressure-contact-deformed with the taper surface so that the taper surface and the inner surface of the main pipe are in close contact with each other in a diameter-expanding manner, regardless of fluctuations in the pipe diameter and wall thickness of the main pipe. A large fastening strength can be secured, and the purpose of reliably preventing external leakage of fluid in the pipe is achieved.

[0007]

According to the present invention, the fitting force obtained by fitting the insertion portion of the pedestal for connecting a branch pipe into the through hole of the main pipe, and the peripheral portion of the through hole from the inner and outer surfaces of the main pipe are cylindrical. See
Even if the pipe diameter and wall thickness of the main pipe fluctuates, this fluctuation is involved because they are fastened together by the clamping force obtained by sandwiching between the base member and the saddle part of the branch pipe connecting pedestal. It can be securely attached with a large fastening strength. Further, the fitting portion between the through hole and the insertion portion of the branch pipe connection pedestal is deformed under pressure contact with the taper surface of the distal end portion of the insertion portion by rotating and rotating the tubular support. Since it is sealed by the cylindrical seal member that is in close contact with the taper surface from the taper surface to the inner surface of the main pipe in a radially expanded manner, it is possible to reliably prevent the fluid in the pipe from leaking to the outside.

[0008]

Embodiments of the present invention will be described below with reference to the drawings. 1 and 2, the branch pipe connection joint includes a branch pipe connection pedestal 5 screwed to a predetermined position of the main pipe 1, and a pipe joint 6 for attaching a branch pipe (not shown) to the pedestal 5. It comprises a tubular seal member 7 for sealing the connection between the pedestal 5 and the main pipe 1 from the inside, and a tubular support 8 detachably attached to the pedestal 5.

The main pipe 1 is, for example, a cast iron buried gas pipe, and a lining layer 9 is formed on the inner surface of the main pipe 1 in order to extend the life of the main pipe by adding a resin pipe such as hard vinyl chloride. A screw hole 10 for mounting a pedestal is formed at a predetermined position of the main pipe 1, and a through hole 11 having substantially the same diameter as the screw hole 10 is concentrically formed in the lining layer 9.

The pedestal 5 for connecting the branch pipe is a circular saddle portion 5A.
And a male screw portion 12 formed on the outer periphery of the insertion portion 5B, which has an insertion portion 5B continuously provided on the lower side of the saddle portion 5A.
When the saddle portion 5A is screwed into the screw hole 10 of the
The main pipe 1 is saddle-fixed to the main pipe 1 through the support 13, and the male screw portion 6A of the pipe joint 6 is inserted into the branch pipe connecting screw hole 14 formed in the saddle portion 5A.
The branch pipe is branched from the main pipe 1 through the pipe joint 6 and the pedestal 5 by screwing and connecting the branch pipe to the branch cylindrical portion 6B protruding to the side of the pipe joint 6. In addition, between the spacer 13 and the saddle portion 5A of the pedestal 5 and the outer surface of the main pipe 1,
Packings P1 and P2 are interposed. Further, a cylindrical support body mounting screw hole 15 is formed so as to communicate concentrically with the branch pipe connecting screw hole 14 from the saddle portion 5A side toward the inserting portion 5B side, and the distal end portion of the inserting portion 5B is the tip. The taper surface 16 is formed so that the diameter thereof gradually decreases.

The tubular support 8 is screwed into the tubular support mounting screw hole 15 of the branch pipe connection base 5. The cylindrical support 8 is formed with a male screw portion 8A which is screwed into the cylindrical support mounting screw hole 15 on the outer periphery thereof, a flange portion 8B is formed on the outer periphery of the lower end portion thereof, and a male screw portion is formed at the center thereof. A through hole 8C having a hexagonal cross-section concentric with 8A is formed.

The tubular seal member 7 is made of an elastic material such as rubber, and is provided with a collar of a tubular support 8 via ring retainers 17 made of metal or resin having a small frictional resistance. A backup ring 18 which is loosely fitted on the portion 8B and made of a soft metal such as lead is externally fitted. Therefore, the cylindrical support member 8 and the backup ring 18 are pressed and deformed to the taper surface 16 of the branch pipe connecting pedestal 5 by rotating the cylindrical support body 8 and screwing it upward.
The tubular seal member 7 is in close contact with the taper surface 16 from the taper surface 16 to the inner surface of the main pipe 1 in a radially expanded form.

Next, a procedure for newly connecting a branch pipe to the main pipe 1 will be described. First, a screw hole 10 for mounting a pedestal is formed at a predetermined position of the main pipe 1 so as to penetrate therethrough. Next, insert a resin pipe into the main pipe 1, and inside the resin pipe
Main pipe 1 by supplying high-pressure fluid and expanding the diameter of the resin pipe
The lining layer 9 is formed by being attached to the inner peripheral surface of the. Subsequently, a through hole 11 which is concentric with the screw hole 10 and has a substantially equal diameter is formed. In the case of a cast iron pipe to which a branch extraction pipe joint is attached, the joint is removed and a through hole 11 concentric with the screw hole 10 is formed in the lining layer.

Next, as shown in FIG. 3, the tubular seal member 7 and the backup ring 18 are preliminarily loosely fitted on the collar portion 8B of the tubular support 8, and the upper end of the tubular support 8 is mounted. Is temporarily screwed into the tubular support attachment screw hole 15 of the branch pipe connection base 5, and then the spacer 13 is interposed between the saddle portion 5A of the branch pipe connection base 5 and the main pipe 1. In this state, the outer peripheral male screw portion 12 of the insertion portion 5B is screwed into the screw hole 10 of the main pipe 1 to insert the tubular seal member 7 and the backup ring 18 into the main pipe 1.

Next, as shown in FIG. 4, through the branch pipe connecting screw hole 14 and the cylindrical support attaching screw hole 15 of the branch pipe connecting pedestal 5, the tubular support 8 is penetrated with a hexagonal cross section. The hexagonal head 19A of the hand tool 19 is fitted into the hole 8C. Subsequently, the manual tool 19 is rotated to screw the tubular support 8 upward. As a result, the tubular seal member 7 and the backup ring 18 are deformed by pressure contact with the taper surface 16 of the pedestal 5 for branch pipe connection as shown in FIG. 5, and the tubular seal member 7 is taped. From the surface 16 to the inner surface of the main pipe 1, the particles are in close contact with each other in an expanded shape. By pulling out the manual tool 19, the mounting state shown in FIGS. 1 and 2 is obtained.

The upper surface of the collar portion 8B of the cylindrical support 8 and the cylindrical sheet.
Between the lower surface of the ruler member 7 and the lower surface of the backup ring 18, a metal or a resin having a small frictional resistance is used.
The retainers 17, 17 are interposed. Therefore,
The rotation of the tubular support 8 is not transmitted to the tubular seal member 7 and the backup ring 18. That is, the relative slip between the upper surface of the collar portion 8B and the lower surface of the lower retainer 17, the relative slip between the upper surface of the lower retainer 17 and the lower surface of the upper retainer 17, and the upper retainer. The cylindrical support 8 is formed by three relative slippages of the upper surface of the na 17 and the lower surface of the tubular seal member 7 and the backup ring 18.
The rotation transmission from the seal member 7 to the backup ring 18 can be reliably blocked. Therefore, although the tubular seal member 7 is pressed against the taper surface 16 by screwing the tubular support member 8 upward,
The tubular seal member 7 will not be loaded with the turning force (torque) of the tubular support 8 and will not damage the tubular seal member 7.

As described above, the cylindrical seal member 7 is formed in the outer periphery of the insertion portion 5B and the lining layer 9 by closely adhering to the inner surface of the main pipe 1 from the taper surface 16 in a radially expanded manner. The gap between the inner periphery of the through hole 11 is sealed,
Surely prevent external leakage of fluid in the pipe such as gas. Also,
The backup ring 18 is deformed and the tubular seal member 7 is deformed.
Since the cylindrical seal member 7 is supported, the reliable seal state of the tubular seal member 7 can be maintained for a long period of time.

[0018]

As described above, according to the present invention, the fitting force obtained by screwing (fitting) the insertion portion of the branch pipe connecting pedestal into the through hole of the main pipe, and the peripheral portion of the through hole. Since it is fastened in cooperation with the clamping force obtained by sandwiching between the tubular seal member and the saddle part of the branch pipe connecting pedestal from both inside and outside of the main pipe, the pipe diameter and the meat of the main pipe are Even if the thickness fluctuates, it is possible to surely attach it with a large fastening strength without being involved in this fluctuation. Further, the fitting portion between the through hole and the insertion portion of the branch pipe connection pedestal is deformed under pressure contact with the taper surface of the distal end portion of the insertion portion by rotating and rotating the tubular support. Since it is sealed by the cylindrical seal member that is in close contact with the taper surface from the taper surface to the inner surface of the main pipe in a radially expanded manner, it is possible to reliably prevent the fluid in the pipe from leaking to the outside.

[Brief description of drawings]

FIG. 1 is a vertical sectional side view showing a state in which an embodiment of the present invention is connected to a main pipe.

FIG. 2 is a front view in vertical section of FIG.

FIG. 3 is a vertical cross-sectional front view of a state in which the main pipe is screwed.

FIG. 4 is a vertical sectional front view showing a state in which a manual tool is fitted.

FIG. 5 is a vertical cross-sectional front view showing a state in which the turning operation by the manual tool is completed.

FIG. 6 is a partially cutaway side view showing a conventional example.

[Explanation of Codes] 1 main pipe 5 pedestal for connecting branch pipe 5A saddle part 5B insertion part 7 cylindrical seal member 8 cylindrical support 8A male screw part 8B collar part 8C cross-section square through hole 10 screw hole (through hole) 14 Branch pipe connection screw hole 15 Cylindrical support mounting screw hole 16 Tapered surface

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Tomoyuki Nakao 4-1-2, Hirano-cho, Chuo-ku, Osaka City, Osaka Prefecture Osaka Gas Co., Ltd. (72) Inventor Yoshiaki Minade 153 Tajime-cho, Kishiwada-shi No. 1 day Inside Steel Pipe Fitting Co., Ltd. (72) Inventor Ryo Otsubo One day at 153 Tajime-cho, Kishiwada City, Osaka Prefecture Inside Steel Pipe Fitting Co., Ltd.

Claims (1)

[Claims] 1. A screw hole for connecting a branch pipe, comprising: a saddle part for saddle-riding on the main pipe, and an insertion part connected to the saddle part and fitted into a through hole formed in the main pipe to be inserted into the main pipe. And a cylindrical support mounting screw hole that is concentrically communicated from the saddle part side and is formed so as to penetrate therethrough, and a branch pipe connection pedestal in which the tip of the insertion part is formed on the taper surface, and the cylindrical support. A cylindrical support body having a male screw portion to be screwed into the mounting screw hole, a flange portion formed on the outer periphery of the lower end portion, and a rectangular through hole having a cross section concentric with the male screw portion, and a collar of the cylindrical support body. And a cylindrical seal member that is loosely fitted onto the main portion, and in which the insertion portion of the pedestal is fitted into the through hole of the main pipe and the saddle portion is saddle-mounted on the main pipe, the cylindrical support of the pedestal is provided. The tubular seal member is pressed against the taper surface by rotating and screwing the tubular support member temporarily fixed to the body mounting screw hole. A branch pipe connecting joint, characterized in that it is deformed so as to be in close contact with the inner surface of the main pipe in a radially expanded manner.