JP2561693B2 - Pipe fitting - Google Patents

Description

TECHNICAL FIELD The present invention relates to a pipe joint used for piping such as a water pipe and a gas pipe.

(Prior art) Recently, as a pipe joint used for piping such as water pipes,
Plug-in type pipe joints have been developed which can fix the connecting pipe by simply inserting the pipe to be connected. In such a plug-in type pipe joint, it is necessary that the end of the connecting pipe can be easily inserted and the end of the inserted connecting pipe cannot be easily pulled out. For this reason, plug-in type pipe joints are normally used in Japanese Patent Publication No. Sho 21-21905 and Japanese Examined Patent Publication No. 55-25317.
As disclosed in Japanese Unexamined Patent Publication (Kokai), etc., a split ring for fixing the connecting pipe is provided in the tubular joint body.
A part of the split ring in the same direction is divided, and the diameter can be reduced and the diameter can be increased. The split ring has a diameter slightly smaller than that of the connecting pipe when it is not fitted over the end portion of the connecting pipe, and when the connecting pipe is inserted into the joint main body, the connecting pipe is inside the split ring. Inserted in. The split ring expands in diameter when the connecting pipe is inserted and is fitted onto the outer peripheral surface of the connecting pipe. When the connecting pipe is about to come out of the joint main body, the split ring comes into contact with the tapered portion on the inner peripheral surface of the joint main body, the diameter thereof is reduced, and the divided portion is locked to the connecting pipe.

(Problems to be Solved by the Invention) In such a conventional pipe joint, in order to increase the locking force between the connecting pipe and the split ring, the split ring is locked to the connecting pipe in a large area. ， The split ring shall be long in the axial direction of the connecting pipe. However, in this case, the sectional area of the split ring becomes large, and a great deal of force is required when inserting the connecting pipe into the split ring. Further, since it becomes difficult to deform the split ring, it is not easy to fit the split ring at a predetermined position in the joint body.

The present invention solves the above-mentioned conventional problems, and an object thereof is to be able to insert a connecting pipe into a joint body with a comparatively small force, and to prevent the connecting pipe from coming off from the joint body. It is to provide a large pipe joint.

Still another object of the present invention is to provide a pipe joint that does not cause damage to the connecting pipe even when high pressure is applied to the connecting pipe.

(Means for Solving the Problem) The pipe joint of the present invention has a tubular shape in which the end portion of the connecting pipe is inserted from the opening portion at one end, and the inner peripheral side portion thereof becomes the opening portion side. A joint body provided with a concave groove having a conical taper portion that gradually reduces in diameter, and a connecting pipe that is disposed in the concave groove of the joint body and is inserted into the joint body. An annular shape that can be fitted externally, and has a substantially circular cross section that twists when it comes into contact with the conical taper portion of the recessed groove, and the twisting surface parallels the taper portion And a retaining ring each having a retaining portion that retains the retaining portion, thereby achieving the above object.

(Example) Hereinafter, the present invention will be described with reference to Examples.

As shown in FIG. 1, the pipe joint of the present invention includes a tubular joint body 10 that is externally fitted to an end portion of a connecting pipe 40, a sealing material 20 disposed in the joint body 10, A retaining ring (31) disposed inside the joint body (10).

The joint body 10 in the pipe joint 1 of the present invention has one end
An opening 11 into which the connecting pipe 40 is inserted is provided, and an annular groove 12 for a sealing material is provided on the inner peripheral surface in the vicinity of the opening 11. The groove 12 for the sealing material has a structure in which the opening 11 side is deep and the inner rear side is shallow. For example, a rubber sealing material 20 is fitted and fixed in the groove 12 for the sealing material. There is. The sealing material 20 is in close contact with the outer peripheral surface of the end portion of the connecting pipe 40 inserted into the joint body 10 and liquid-tightly seals the outer peripheral surface of the connecting pipe 40 and the inner peripheral surface of the joint body 10.

A recess 13 for a retaining ring is provided on the inner peripheral surface of the joint body 10 on the inner side in the axial direction with respect to the groove 12 for seal material. A retaining ring 31 is fitted in the retaining ring concave groove 13.

The retaining ring 31 is formed in an annular shape with a part cut out, for example, of steel. The retaining ring 31
Has a substantially circular cross section, and has a diameter slightly smaller than the outer diameter of the connection pipe 40 inserted into the joint body 10. When the connection pipe 40 is inserted into the retaining ring 31, the retainer Ring 31
Expands in diameter and is brought into close contact with the outer peripheral surface of the connecting pipe 40.

A locking portion 31a, which is notched in a stepwise manner, is formed over the entire circumference at an inner peripheral side portion on the inner back side of the joint body 10 in the retaining ring 31. The locking portion 31a is cut out so as to have, for example, two surfaces parallel to the outer peripheral surface of the connecting pipe 40, and three corner portions are formed.

Groove for retaining ring with retaining ring 31
The inner side of the joint body 10 has a space 13 slightly larger than the retaining ring 31. Groove for retaining ring 13
The inner side surface 13b of the joint body 10 is substantially orthogonal to the axis of the joint body 10. The retaining ring recess groove 13 has a conical taper portion 13a on the opening 11 side of the joint body 10 whose diameter gradually decreases toward the opening 11 side.

The retaining ring 31 is fitted onto the connecting pipe 40,
When the connecting pipe 40 moves in the direction of coming out of the joint body 10, it comes into contact with the taper portion 13a of the retaining ring recess groove 13. At this time, since the outer peripheral surface of the retaining ring 31 that comes into contact with the tapered portion 13a has an arc shape,
The retaining ring 31 is twisted by the reaction force from the 13a, and the locking portion 31a bites into the connecting pipe 40. When the connecting pipe 40 tries to come out of the joint body 10 further, if the outer peripheral surface of the retaining ring 31 that comes into contact with the tapered portion 13a of the retaining ring concave groove 13 has an arc shape, the retaining ring 31 is further twisted, The locking portion 31a may be twisted to a state where it is not locked to the outer peripheral surface of the connecting pipe 40.

In the present invention, in order to solve such a problem, the retaining ring 31 is provided with a locking surface 31b. The locking surface 3
The cross section 1b is cut out in a planar shape over the entire circumference from a position substantially symmetrical with respect to the locking portion 31a in the cross section to a position on the opening 11 side of the joint body 10. The locking surface
31 is a conical taper portion of the retaining ring concave groove 13 in the joint body 10 due to the retaining ring 31 twisting.
It will be parallel to 13a.

As described above, in the pipe joint 1, the retaining ring 31 is fitted in the retaining ring recess groove 13 of the joint body 10.
Moreover, the seal material 20 is fitted and fixed in the groove 12 for the seal material. When the connecting pipe 40 is inserted from the opening 11 of the joint body 10, the tip of the connecting pipe 40 is inserted into the retaining ring 31. The retaining ring 31 inserted in the connecting pipe 40 is in a diameter-expanded state and is brought into close contact with the outer peripheral surface of the connecting pipe 40. When the connecting pipe 40 is further inserted into the joint body 10, the retaining ring 31 moves in parallel with the connecting pipe 40, and the inner side surface 13 of the retaining ring concave groove 13 inside the joint body 10.
Contact b. In this state, the connecting pipe 40 is further inserted into the inner side of the joint body 10. At this time, the side surface 13b of the retaining ring groove 13 is substantially orthogonal to the axis of the joint body 10. Since the state is in the state, the force from the side surface 13b in the axial direction of the joint body 10 acts on the retaining ring 31, and the retaining ring 31 stops in a state of contacting the side surface 13b.
The connecting pipe 40 is inserted into the joint body 10 to a predetermined length.

In such a state, clean water, for example, flows into the pipe joint 1 and the connection pipe 40 from the inner back side of the joint body 10. As a result, a force is applied to the connecting pipe 40 in a direction in which the connecting pipe 40 tends to come out of the joint body 10, and the connecting pipe 40 moves in a direction in which it comes out of the joint body 10. With this movement, the retaining ring 31 fitted on the connection pipe 40 in the joint body 10 moves in parallel with the connection pipe 40. Then, as shown in FIG. 2, the peripheral surface of the retaining ring 31 adjacent to the locking surface 31b abuts the conical taper portion 13a of the retaining ring concave groove 13.

In this state, when the connecting pipe 40 moves further in the direction of coming out of the joint body 10, the second retaining ring 31 has a second
As shown in the figure, a reaction force from the conical taper portion 13a of the retaining ring recess groove 13 is applied, and a force along the taper portion 13a is applied. As a result, a twisting force in the direction indicated by arrow A in FIG. 2 acts on the retaining ring 31, the retaining ring 31 is twisted, and the locking portion 31a of the retaining ring 31 is twisted.
Are locked to the outer peripheral surface of the connecting pipe 40. At this time, as shown in FIG. 3, the locking surface 31b of the retaining ring 31 becomes parallel to the conical taper portion 13a of the retaining ring concave groove 13 when the retaining ring 31 is twisted. The tapered portion 13a
Surface contact with. As a result, the force applied to the retaining ring 31 in the twisting direction is reduced, and the locking portion 31a is connected to the connecting pipe 4
0 It is held in such a state that it digs into the outer peripheral surface by a certain amount. Then, the connecting pipe 40 is stopped from moving in the direction in which it is trying to come out of the joint body 10.

Even if a force is applied to the connecting pipe 40 in the direction of coming off the joint body 10, the locking surface 31b of the retaining ring 31 is in surface contact with the conical taper portion 13a of the retaining ring concave groove 13, The retaining ring 31 does not twist. Therefore, there is no fear that the retaining ring 31 will be excessively twisted and its locking portion 31a will release the locking with the outer peripheral surface of the connecting pipe 40, and the connecting pipe 40 can be reliably attached to the joint body 10 by the retaining ring 31.
The locking surface 31a of this is prevented from coming off. In addition, the retaining ring 3
The locking surface 31a of 1 is the tapered portion 13a of the groove 13 for the retaining ring.
The tapered portion 13a is prevented from being strongly pressed by the arcuate outer peripheral surface of the retaining ring 13 by abutting against, and there is no fear of damaging the tapered portion 13a.

(Effect of the Invention) Since the pipe joint of the present invention uses the retaining ring having a substantially circular cross section as described above, the connecting pipe can be easily inserted into the retaining ring. When the connecting pipe moves in the direction in which the connecting pipe comes out, a twisting force acts on the retaining ring to lock it on the outer peripheral surface of the connecting pipe, so that the connecting pipe is reliably retained.

When the retaining ring is twisted by a predetermined amount, the locking surface provided on the retaining ring becomes parallel to the taper portion of the retaining ring concave groove and comes into surface contact with the taper portion. Has no further twisting force.
Therefore, the locking portion of the retaining ring is retained in a state of being embedded in the outer peripheral surface of the connecting pipe by a predetermined amount, and the retaining ring can reliably prevent the connecting pipe from coming off the joint body. Further, even if a force is applied to the connecting pipe in the direction of coming out of the joint body, the retaining ring does not excessively twist and its locking portion does not cancel the engagement with the outer peripheral surface of the connecting pipe, and the connecting pipe 40 becomes the joint body. Securely locked out from 10. Further, since the entire retaining surface of the retaining ring is pressed from the taper portion, the retaining portion of the retaining ring does not go deep into the connecting pipe and damage to the connecting pipe is prevented.

[Brief description of drawings]

FIG. 1 is a partially cutaway side view of an essential part showing an example of the pipe joint of the present invention, and FIGS. 2 and 3 are enlarged views of the essential part for explaining the operation thereof. 1 …… Pipe joint, 10 …… Coupling body, 11 …… Opening, 12 …… Seal groove, 13 …… Retaining ring groove, 13a …… Conical taper, 13b …… Side, 20 …… Seal material, 31 …… Prevention ring, 31a …… Locking part.

Claims (1)

(57) [Claims] 1. A connecting pipe having a cylindrical shape in which an end portion is inserted from an opening portion at one end, and an inner peripheral portion thereof having a conical shape whose diameter gradually decreases toward the opening portion side. A joint main body provided with a concave groove having a tapered portion, and an annular shape which is arranged in the concave groove of the joint main body and can be externally fitted to a connecting pipe inserted into the joint main body, and A dropout that has a substantially circular cross-section that twists when it comes into contact with the conical tapered portion of the concave groove, and that has a locking surface that is parallel to the tapered portion and a locking portion that locks to the outer peripheral surface of the connecting pipe due to the twisting. A pipe joint equipped with a retaining ring.