JP3000435B2 - Branch pipe fitting - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a metal pipe such as cast iron for connecting a metal branch pipe to a pipe wall of a main pipe made of a synthetic resin such as polyethylene which is recently used as a pipe for water supply and sewage and gas. The present invention relates to a technique for preventing leakage in a branch pipe joint made of steel.

[0002]

2. Description of the Related Art As shown in FIGS. 5 and 6, a conventional branch pipe joint has a circular through hole (1) at the center (it may be drilled at the same time as the branch hole) and is joined. A substantially half-cylindrical (saddle-shaped) saddle (3) having a saddle joint surface (saddle inner surface) having the same curvature as the outer wall of the main pipe (2) made of a synthetic resin to be formed, and a periphery of the through hole (1). A joining means (5) such as a male screw, a female screw, a union, and freely rotatable and slidable with respect to the pipe end of a metal branch pipe (4) to be formed so as to project from the outer surface of the saddle (3) and to be joined to the joint tip. And a ring-shaped rubber packing (7) attached to the circular packing fitting portion (3a) of the saddle (3) formed around the through hole (1). And a substantially half-tubular saddle fastening washer having a joint surface (inner surface) having the same curvature as the outer tube wall of the main tube (2). 8) and the saddle (3) are held together by the outer wall of the main pipe (2), and tightened between the washer (8) and the flanges (9) and (10) projecting from the side edge of the saddle (3) and facing each other. The bolt (11) is hung via the fastening nut (12), and the washer (8) and the saddle (3) are fastened to the outer wall of the main pipe (2). Thereby, the branch pipe joint is attached to the outer pipe wall of the main pipe (2), and the packing (7) is crimped to the inner surface of the saddle (3) and the outer pipe wall of the main pipe (2) around the through hole (1). Then, the water is stopped. Then, after attaching the branch pipe joint to the main pipe (2), a drilling tool such as a drill is inserted into the joint main body (6) through an opening at the end of the joint, and the main pipe (2) corresponding to the through hole (1) is inserted. ), A circular branch hole (13) is made in the pipe wall, and then the joint body (6) is formed.
The branch pipe (4) is joined to the joint tip of the above (1) via the joining means (5). Thereby, the branch pipe (4) branches from the pipe wall of the main pipe (2).

[0003]

When the main pipe (2) is a synthetic resin pipe, the pipe wall around the branch hole (13) of the main pipe (2) is formed inside by the creep phenomenon due to the pressing force of the packing (7). There is a problem that the packing (7) does not work and the leakage occurs. In addition, the synthetic resin pipe has a small coefficient of friction and a large coefficient of expansion.
The saddle is likely to be displaced due to rotation and sliding due to shrinkage, which also causes leakage.

[0004]

SUMMARY OF THE INVENTION The present invention provides a metal branch pipe joint for connecting a metal branch pipe to a synthetic resin main pipe, the saddle being joined to a pipe wall of the main pipe. A tubular joint body protruding from the periphery of the through hole to the upper surface of the saddle,
In a branch pipe joint provided with a packing made of an elastic material disposed between a saddle and a main pipe, the branch pipe joint is engaged with a branch hole of the main pipe.
Curvature retention with a curved end face of the same curvature as the inner wall of the main pipe
In addition to providing members, the projections formed on the inner surface of the joint body
A vertically split groove that fits slidably and an
And the engaging claw that restricts withdrawal from the main pipe to the outside.
The holding member has a curvature holding member that prevents the pipe wall of the main pipe around the branch hole from being bent inward by the curvature holding member, thereby preventing the packing from working, and also displacing the saddle with the curvature holding member. It prevents the occurrence of leakage.

[0005]

Embodiments of the present invention will be described below in detail with reference to the drawings. 1 to 3 show a branch pipe joint according to the present invention, in which a circular through hole (20) is provided at the center.
(May be drilled at the same time as the branch hole.)
A substantially half-cylinder (saddle-shaped) saddle (22) having a saddle joint surface (saddle inner surface) having the same curvature as the outer tube wall of the synthetic resin main tube (21) to be joined, and a through hole (20). On the outer surface of the saddle (22) from the periphery (in the radial direction of the main pipe (21))
A male screw, a female screw, a union with respect to the pipe end of the metallic branch pipe (23) to be formed and to be joined to the joint tip;
A cylindrical joint body (25) having joining means (24) (female thread is shown in the embodiment) such as rotatable and slidable.
And an annular rubber packing (26) mounted in a circular packing fitting groove (22a) of a saddle (22) formed around the through hole (20), and an outer wall of the main pipe (21). The saddle fastening washer (27), which is substantially half-split and has the same curvature (joint surface) (inner surface), and the saddle (22) are held together by the outer wall of the main pipe (21), and the washer (27)
A fastening bolt (30) is hung between a flange (28) (29) protruding from a side edge of the saddle (22) and a facing nut via a fastening nut (31), and a washer (27) and a saddle (22) are attached to a book. Tighten to the outer wall of the pipe (21). Thereby, the branch pipe joint is attached to the outer pipe wall of the main pipe (21), and the packing (26) is crimped to the inner surface of the saddle (22) and the outer pipe wall of the main pipe (21) around the through hole (20). And
Water shutoff is performed. Then, after attaching the branch pipe joint to the main pipe (21), a drilling tool such as a drill is inserted into the joint main body (25) through an opening of the joint tip, and the main pipe (21) corresponding to the through hole (20) is inserted. ), A circular branch hole (32) is made in the pipe wall, and then the branch pipe (23) is joined to the joint tip of the joint body (25) via the joining means (24). Thereby, the branch pipe (23) branches from the pipe wall of the main pipe (21).

In the present invention, the pressure of the packing (26) against the pipe wall of the main pipe (21) around the branch hole (32) causes the pipe of the main pipe (21) around the branch hole (32) to be pressed. The wall is bent inward, the packing (26) does not work, and the curvature holding member (3) prevents leakage from occurring.
3) is provided in the branch pipe joint described above.

The curvature holding member (33) shown in this embodiment is
As shown in FIG. 4, the main body (34) is made of a rust-resistant metal tube or a synthetic resin tube such as stainless steel or hard synthetic resin. One end of the main body (34) is formed on an end surface (35) orthogonal to the axis of the main body (34).
Is formed on a curved end surface (36) having the same curvature as the inner wall of the main tube (21), and an engaging claw (37) is formed to protrude outward from the outer peripheral surface of the curved end portion of the main body (34). I have. Four vertical grooves (39) into which four projections (38) projecting from the inner surface on the base end side of the joint main body (25) at 90 ° intervals are slidably fitted are formed in the main body (3).
From the curved end face (36) of (4) to just before the end face (35), they are formed at 90 ° intervals on the peripheral wall of the main body (34).

A branch pipe joint is attached to the main pipe (21), a branch hole (32) is made in the main pipe (21), and then the above-mentioned curvature holding member (33) is attached. The body (34) is slightly pushed into the interior of the body (25) from the joint tip opening from the side of the curved end surface (37).
At this time, the lower part of the main body (34) in the range where each vertical groove (39) is formed by each vertical groove (39) connects the main body (34) with the fitting hole diameter, the joint body inner diameter, the packing inner diameter, and the branch hole diameter. Accordingly, the diameter (the maximum diameter of the main body) of the claw portion (37) of the main body (34) is reduced. In this state, the main body (34)
Is rotated so that one reference vertical groove (39) matches one reference protrusion (38), and all protrusions (3
8) and the circumferential direction of the main body (34) with respect to the joint main body (34) so that all the vertical grooves (39) coincide with each other. In this state, the main body (34) is further connected to the joint main body (2).
5) By slightly pushing in the inside, each vertical groove (3
Each projection (38) is fitted into the open end of 9). In this state, the main body (34) is further pushed into the joint main body (25), so that each projection (38) moves toward the closed end (groove bottom) side in each vertically split groove (39).
The curved end of the body (34) is pushed into the branch hole (32) through the inner opening of the packing (26). When the claw portion (37) of the main body (34) protrudes from the inside of the branch hole (32) to the inside of the main pipe (21), the lower portion of the main body (34) in the area where the vertical groove (39) is formed expands. The claw (37) is restored to the original diameter and the main pipe (2) at the periphery of the branch hole (32) is restored.
In addition to the engagement with the inner wall of the pipe of 1), each projection (38) shifts to and engages with the closed end (groove bottom) of each vertically divided groove (39) at the engagement position, so that the main body is further increased. (34) Pushing inside the joint body (25) is restricted.

As described above, the curvature holding member (33) has an upper end engaged with the inner surface of the joint body (25) and a lower end provided with the branch hole (3).
2) By engaging the inner wall of the surrounding main pipe (21), the pipe wall of the main pipe (21) is engaged with the joint side, and the branch hole (32) is formed.
The inner wall of the surrounding main pipe (21) is prevented from being bent inward by the pressing force of the packing (26), and the bent deformation prevents the packing (26) from working and prevents leakage from occurring. It is.

The curvature holding member (33) has a main body (34) fitted in the joint main body (25), the packing (26) and the main pipe (21). Is simultaneously performed in the direction of the pipe axis and the rotation of the branch joint in the direction of the pipe peripheral surface is also performed, so that a leak due to a displacement of the branch joint with respect to the main pipe (21) is also prevented.

The engaging portion of the curvature holding member (33) protruding from the inner wall of the main pipe (21), that is, the claw (39) of the main body (24) is formed by the curvature of the inner wall of the main pipe (21). Since the main pipe (21) has the same curvature as that of the main pipe (21), the amount of swelling from the inner wall of the main pipe (21) can be reduced, and the flowing water resistance hardly increases.

The projection (38) and the vertically dividing groove (39) are provided with a reference member because the claw (39) is attached to the main pipe (21) when the curvature holding member (33) is attached. This is for positioning the curvature holding member (33) at a rotational position along the inner wall of the pipe.

The vertical groove (39) has a projection (3) even when the lower part of the main body (34) in this forming area is most reduced in diameter.
8) is formed to have a groove width capable of slidably fitting therein, and the fitting of the vertically dividing groove (39) and the projection (38) also serves as a pushing guide and a detent for the curvature holding member (33). Thus, the curvature holding member (33) can be mounted smoothly.

[0014]

As is apparent from the above embodiments, the present invention is characterized in that the main pipe (21) made of synthetic resin is connected to the branch pipe (23) made of metal.
And a metal branch pipe joint for connecting the main pipe (2
A saddle (22) to be joined to the tube wall of 1) and a through hole (2)
A cylindrical joint body (25) protruding from the periphery of 0) to the upper surface of the saddle (22), and a packing (26) made of an elastic material disposed between the saddle (22) and the main pipe (21). In the branch pipe joint, the branch pipe (32) of the main pipe (21)
A curved end face having the same curvature as the inner wall of the main pipe (21) when engaged.
When the curvature holding member (33) having (36) is provided,
And a projection (38) formed on the inner surface of the joint body (25).
Vertically split groove (39) to be slidably fitted, and curved end face
Provide outside of (36) and withdraw from outside of main pipe (21)
The engagement claw (37) for restricting the curvature and the curvature holding member (33)
The curvature holding member (33) prevents the tube wall of the main pipe (21) around the branch hole (32) from being bent inward.
This prevents the packing (26) from working and prevents the saddle (22) from being displaced.
Therefore, there is an effect that leakage can be prevented.

[Brief description of the drawings]

FIG. 1 is a sectional front view showing a mounted state of a branch pipe joint of the present invention.

FIG. 2 is a sectional side view showing an attached state of the branch pipe joint of the present invention.

FIG. 3 is a partially sectional front view showing a disassembled state of the branch pipe joint of the present invention.

FIG. 4 is an enlarged front view of a curvature holding member.

FIG. 5 is a cross-sectional front view showing an attached state of a conventional branch pipe joint.

FIG. 6 is a cross-sectional front view showing an attached state of a conventional branch pipe joint.

[Explanation of symbols]

 (20) Through hole (21) Main pipe (22) Saddle (23) Branch pipe (25) Joint body (26) Packing (32) Branch hole (33) Curvature holding member

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-55-51195 (JP, A) JP-A-8-135572 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) F16L 41/02-41/08

Claims (1)

(57) [Claims] 1. A metal branch pipe joint for connecting a metal branch pipe (23) to a synthetic resin main pipe (21),
A saddle (22) to be joined to the pipe wall of the main pipe (21), a tubular joint body (25) protruding from the periphery of the through hole (20) to the upper surface of the saddle (22), a saddle (22) and the main pipe (2
In the branch pipe joint and a packing (26) made of elastic material disposed between the 1), a branch hole in the main pipe (21)
(32) and the same curvature as the inner wall of the main pipe (21)
A curvature holding member (33) having a curved end surface (36) is provided.
And a projection formed on the inner surface of the joint body (25).
A vertically split groove (39) slidably fitted in (38);
Provided outside the curved end face (36) and outside the main pipe (21)
And an engagement claw (37) for restricting extraction to a curvature holding member
(33) A branch pipe joint characterized by being configured to have .