JP2001082654A - Pipe joint - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pipe joint using an in-core capable of easily mounting on a fluid pipe by arranging a cutoff having a prescribed width opened to an end part of an opposite side to a leading-in part in the in-core, in the vicinity of a packing, and elastically contract a diameter in the radial direction. SOLUTION: A fluid pipe 2 mounted with an in-core 8 therein is inserted until abutting to a stopper 3d from an end part of a push ring 4 temporarily fastened to a joint main body 3, a temporarily fastened nut 10 is uniformly fastened until a flange 3b abuts on a flange 4b, and a joining operation is completed. In the case where the in-core 8 is mounted on the fluid pipe 2, it can be inserted into the fluid pipe 2 from the leading-in part 8b with diameter formed smaller than an inner diameter of the fluid pipe 2. Since the cutoff 8d is disposed on the main body part 8a with diameter formed larger than the inner diameter of the fluid pipe 2, its diameter can be contracted. Accordingly, an inserting resistance is reduced, a workability for insertion is improved, and a mounting operation is easily carried out.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pipe joint used for joining water pipes, gas pipes, and plant pipes made of a soft synthetic resin such as polyethylene.

[0002]

2. Description of the Related Art Conventionally, a lock ring E is pushed by a press ring B as shown in FIG. 4 as a pipe joint of a fluid pipe of this kind, and the lock ring E connects a packing C via a retainer D to the joint body A.
It is known to push them into.

The joint body A has a packing C on the inner peripheral surface at the end.
Is constituted by an enlarged diameter portion A1 that accommodates the joint body A, a flange A2 formed on the outer surface thereof, and a stopper A3 protruding from the inner peripheral surface at the back of the enlarged diameter portion A1. Packing C, retainer D, whose section is wedge-shaped from the center side,
A lock ring E is disposed, and a fluid pipe P having an inner core with an incore G for preventing a contraction in diameter is inserted so as to abut against the stopper A3.

[0004] A tapered surface B1 whose diameter increases toward the joint body A is formed on the inner peripheral surface of the pressing wheel B, and a flange B2 corresponding to the flange A2 of the joint body A is provided on the outer surface. -Attached to the joint body A by the nut F.

The outer peripheral surface of the lock ring E has a tapered surface B
1 is formed, and an outer tapered surface E1 is formed on the inner peripheral surface.
A blade E2 that cuts into the outer peripheral surface of the fluid pipe P is formed.

In order to join the fluid pipe P with such a pipe joint, first, a press ring B, a lock ring E, a retainer D, a packing C
Are sequentially fitted to the outside, then the insertion portion is inserted into the joint body A, and the packing C, the retainer D, and the lock ring E are pushed into the enlarged diameter portion A1 in this order, and the pressing ring B is pulled toward the joint body A,
Then, the bolt F is inserted through the flanges A2 and B2 of the joint body A and the press ring B, and the nut F is tightened to fasten the press ring B to the joint body A.

When the pressing wheel B is attached to the joint body A by bolts and nuts F, the tapered surface B1 moves in the direction of the joint body A, and the outer diameter of the lock ring E is reduced by the outer tapered surface E1 contacting the tapered surface B1. I do. The blade E2 of the reduced lock ring E bites into the outer peripheral surface of the fluid pipe P, and the incore G prevents the fluid pipe P from reducing the diameter, so that the fluid pipe P is sandwiched between the lock ring E and the incore G. The joint is prevented from being detached from the joint.

[0008] In the pipe joint to which the fluid pipe P is joined,
When the fluid pipe P moves in the direction of coming out of the fitting, the blade E2 bites into the outer peripheral surface of the fluid pipe P, so that the lock ring E also moves together with the fluid pipe P, and the outer tapered surface of the lock ring E moves. The lock ring E is reduced in diameter by the movement of E1 abutting against the tapered surface B1 of the pressing wheel B, and the fluid pipe P
The blade E2 further cuts into the blade, thereby preventing the blade E2 from slipping out.

[0009]

The in-core in such a conventional pipe joint has a constant outer length and a larger outer diameter than the inner diameter of the fluid pipe in order to prevent the in-core from coming out of the mounted fluid pipe. The fluid pipe to which the incore is attached is often a soft synthetic resin pipe such as a polyethylene pipe, and the fluid pipe to which the in-core is mounted is a thin synthetic pipe such as a polyethylene pipe. Since there is a large variation and the tolerance of the pipe diameter and the pipe thickness in each standard of the soft synthetic resin pipe is largely defined, the in-core is formed to have an outer diameter larger than the maximum inner diameter of the fluid pipe that allows for the tolerance.

Therefore, at the time of joining the fluid pipes, it is necessary to insert an incore having an outer diameter larger than the inner diameter of the fluid pipe into the inner peripheral portion of the fluid pipe, and the incore is inserted so as to expand the fluid pipe. . Therefore, a large force is required to mount the incore, and it is hit with a hammer, and it may come out due to the repulsive force of the fluid pipe. Needed a lot.

The problem to be solved by the present invention has been made to solve the above problems, and it is an object of the present invention to provide a pipe joint using an incore which can be easily attached to a fluid pipe.

[0012]

In order to solve the above-mentioned problems, a pipe joint according to the present invention is a joint for holding an insertion portion of a fluid pipe having an incore fitted on an inner peripheral surface thereof in a watertight manner through packing. In a pipe joint comprising a main body, and a lock ring having a tapered surface relatively movable with respect to the joint main body and having a diameter reduced in the vicinity of the insertion portion due to relative movement with the tapered surface, the in-core is thin. A predetermined width opened at an end of the in-core opposite to the introduction portion, which comprises a cylindrical main body portion and an introduction portion connected to the main body portion and having an outer diameter smaller than the inner diameter of the fluid pipe. A notch is provided up to the vicinity of the packing so that the diameter can be elastically reduced in the radial direction. With this feature, the incore can be inserted into the fluid pipe from the introduction section formed to be smaller than the inner diameter of the fluid pipe, so that the resistance in the initial stage of insertion is small, and the incore can be reduced in diameter on the opposite side of the introduction section. Since the notch is provided, a part of the in-core can be inserted with its outer diameter smaller than the inner diameter of the fluid pipe, which reduces insertion resistance and eliminates the need to hammer with a hammer. It is improved and mounting becomes easy. Further, since the incore is elastically reduced in diameter, it is restored after mounting, and is pressed against the inner peripheral surface of the fluid pipe, so that it is prevented from coming out of the fluid pipe, and the mounting position is held and stably fixed.

It is preferable that a circular portion having a diameter larger than the width of the cut is formed at the end point of the cut. This makes it possible to disperse the stress generated at the end point of the cut when the diameter of the incore is reduced, thereby preventing the incore from being damaged.

[0014]

Embodiments of the present invention will be described below with reference to the drawings.

FIGS. 1 to 3 show an embodiment in which polyethylene pipes 2 and 2 are joined using a pipe joint 1 of the present invention.

In the same figure, 3 is a joint body made of ductile cast iron, 4 is a pressing ring fastened to the joint body 3, and 5 is
A lock ring 6 disposed on the inner peripheral surface of the press ring 4 is a packing for joining the fluid pipe 2 to the joint body 3 in a watertight manner, 7 is a retainer for pressing the packing 6, and 8 is an inner peripheral end of the fluid pipe 2. It is an in-core attached to.

A stopper 3d protruding toward the center of the pipe is provided at the center of the inner surface of the joint body 3, and an enlarged diameter portion 3a for accommodating the packing 6 is formed at both ends of the joint body 3, and on the outer surface thereof. A flange 3b is provided continuously, and a locking portion 3c is provided at an end of the enlarged diameter portion 3a to prevent the retainer 7 from moving by contact.

The flange 4b of the pressing ring 4 is provided with a plurality of T-head bolts 9 on the flange 3b provided on the outer peripheral surface of the joint body 3.
And the nut 10, and the lock ring 5 is
The pressing wheel 4 is fastened by the tapered surface 4a.

The lock ring 5 has a split shape made of a synthetic resin harder than the fluid pipe 2, for example, an acetal resin or a metal body such as stainless steel. The outer peripheral surface of the outer tapered surface 5 has substantially the same inclination as the tapered surface 4 a of the pressing ring 4.
a is formed, the maximum outer diameter thereof is set to be larger than the maximum inner diameter of the tapered surface, and a plurality of circumferentially oriented blades 5b are formed on the inner peripheral surface.

As shown in FIG. 3, the in-core 8 has a thin cylindrical main body 8a having an outer diameter slightly larger than the inner diameter of the fluid pipe 2, and a tapered taper formed continuously from one end of the main body 8a. , And a flange 8c protruding from the other end in the outer diameter direction and continuously provided therewith. The outer diameter of the leading end of the introduction portion 8b is formed smaller than the inner diameter of the fluid pipe 2.

Openings 8d are provided at the end of the flange 8c at predetermined intervals in the pipe axis direction, and the terminal end thereof is located near the packing 6 and has a diameter larger than the width of the notch 8d. A circular portion 8e is formed.

The in-core 8 is formed by the cut 8d.
The diameter can be elastically reduced from the flange 8c to the main body 8a with the circular portion 8e as a base.

Using the pipe joint 1 of the above embodiment, a fluid pipe 2
In order to join the fluid pipes 2, first, the introduction portion 8b is pressed against the end of the fluid pipe 2 to be joined, and the in-core 8 is inserted until the flange 8c contacts the end of the fluid pipe 2.

Next, a T-head bolt 9 is inserted into the flange 3b and the flange 4b, and the nut 10 is temporarily tightened, and the pressing ring 4 in which the lock ring 5 and the retainer 7 are mounted is mounted on the expanded portion 3a by the packing 6. Temporarily fix to the inserted joint body 3.

Next, the fluid pipe 2 in which the in-core 8 is mounted is inserted from the end of the press ring 4 temporarily fixed to the joint body 3 until it comes into contact with the stopper 3d, and the nut 10 temporarily tightened is connected to the flange 3b. The flanges 4b are evenly tightened until they come into contact with each other to complete the joining.

In mounting the in-core 8 on the fluid pipe 2, the introduction portion 8 b formed to have a smaller diameter than the inner diameter of the fluid pipe 2.
Can be inserted into the fluid pipe 2, and the main body 8a formed larger than the inner diameter of the fluid pipe 2 has a cut 8d
Is provided, the diameter can be reduced, the insertion resistance is reduced, the workability of insertion is improved, and the mounting is facilitated.

Further, since the in-core is elastically reduced in diameter, the in-core is restored after the mounting and is pressed against the inner peripheral surface of the fluid pipe, so that the in-core is prevented from coming off from the fluid pipe. Therefore, the mounting position is held and is stably fixed.

When the tapered surface 4a and the lock ring 5 move relative to each other, the diameter of the lock ring 5 is reduced by the wedge action, and the blade 5b is prevented from biting into and out of the fluid pipe 2.

At this time, the diameter of the fluid pipe 2 is reduced together with the lock ring 5 but is prevented because the inner core 8 is mounted on the inner peripheral surface, and a cut 8 d is formed in the vicinity of the lock ring 5 of the in core 8. Because it does not have a cylindrical shape, diameter reduction can be reliably prevented.

Although the embodiment of the present invention has been described with reference to the drawings, the specific structure of the present invention is not limited to this.

In the embodiment, only one cut is provided, but a plurality of cuts, such as two or three, are provided on the axis object.
The diameter may be more easily reduced.

Further, the flange portion of the in-core is provided in a tapered shape which spreads gently, but may be provided substantially perpendicularly to the outer diameter direction.

Although the pressing ring has a flange and is fastened to the joint body with bolts and nuts, the pressing ring may be formed in a cap nut shape and screwed into the joint body.

[0034]

According to the present invention, the incore can be inserted into the fluid pipe from the introduction section formed with a smaller diameter than the inner diameter of the fluid pipe, so that the resistance at the initial stage of insertion is small and the opposite side of the introduction section. Is provided with a notch that allows the incore to be reduced in diameter, so that a part of the incore can be inserted by reducing its diameter to an outer diameter smaller than the inner diameter of the fluid pipe, reducing insertion resistance and requiring hammering. In addition, the workability of insertion is improved and the mounting becomes easy. Further, since the incore is elastically reduced in diameter, it is restored after mounting, and is pressed against the inner peripheral surface of the fluid pipe, so that it is prevented from coming out of the fluid pipe, and the mounting position is held and stably fixed.

Since the notch is provided only up to the vicinity of the packing, the incore located near the lock ring is formed in a cylindrical shape, so that deformation of the fluid pipe due to the diameter reduction of the lock ring can be reliably prevented.

According to the second aspect of the present invention, the stress generated at the end point of the cut when the diameter of the incore is reduced can be dispersed, so that the damage of the incore can be prevented.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an embodiment of the present invention.

FIG. 2 is also a side view.

3A is a front view of the in-core, and FIG.

FIG. 4 is a partially cutaway front view showing a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Pipe joint 2 Fluid pipe 3 Joint main body 3a Large diameter part 3b Flange 3c Lock part 3d Stopper 4 Press ring 4a Tapered surface 4b Flange 5 Lock ring 5a Outer taper surface 5b Blade 6 Packing 7 Retainer 8 In core 8a Main body 8b Introduction part 8c Flange 8d Cut 8e Circular part 9 T-head bolt 10 Nut

Claims (2)

[Claims] 1. A joint body for holding an insertion portion of a fluid pipe having an incore fitted on an inner peripheral surface thereof in a watertight manner via a packing;
A lock ring having a tapered surface that is relatively movable with respect to the joint body and having a diameter reduced near the insertion portion by relative movement with the tapered surface, wherein the incore has a thin cylindrical shape. A main body portion, an introduction portion connected to the main body portion and formed with an outer diameter smaller than the inner diameter of the fluid pipe, a notch having a predetermined width opened at an end of the in-core opposite to the introduction portion. A pipe joint provided up to the vicinity of a packing and capable of being elastically reduced in diameter in a radial direction. 2. A circular portion having a diameter larger than the width of the notch is formed at an end point of the notch.
The pipe joint according to 1.