JPH09159080A - Separation prevention pipe joint - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide full bending performance between a socket and an insertion port in the case of inserting the insertion port in the depth of the socket in a separation prevention pipe joint. SOLUTION: In a lock ring storage groove 4 in the internal circumference of a socket 1, a lock ring 5 is held by an elastic ring 6 with its core exposed. An outer circumferential projection 9 which can be engaged with the depth side of the socket, after the diameter of the lock ring 5 is elastically expanded so that its depth part is made to pass to the depth side of the socket, is formed in the outer circumference in the tip of the insertion port 8. An internal circumferential projection 15 for backing up the lock ring is formed in a side toward an inner part than the lock ring storage groove 4. A firrst internal circumferential face 17 having the diameter larger than the internal projection 15 is formed in a side toward inner part than the internal projection 15. A second internal circumferential face 18 having the diameter larger than the internal circumferential projection 15 and smaller than the first internal circumferential face 17 is formed between the first internal circumferential face 17 and the internal circumterential projection 15.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a separation prevention pipe joint, and more particularly to a slip-on type separation prevention pipe joint in which the receiving port and the insertion port can be joined by inserting the insertion port into the receiving port.

[0002]

2. Description of the Related Art In a slip-on type pipe fitting, a receiving material and a receiving material can be joined by mounting a sealing material on the inner periphery of the receiving material and inserting the opening into the receiving material while compressing the sealing material. It is configured as follows. There is also such a slip-on type pipe joint provided with a separation prevention function.

In this disconnection prevention pipe joint, a lock ring accommodation groove is formed on the inner side of the receiving port on the inner side of the seal material accommodation groove, and a lock ring divided in the circumferential direction is attached to the lock ring accommodation groove. ing. A retaining rubber ring for retaining the lock ring is arranged between the outer peripheral side of the lock ring and the inner peripheral side of the lock ring housing groove. A protrusion that can engage with the lock ring from the rear side of the receiving port is formed on the outer periphery of the tip of the insertion port. A small-diameter portion having a diameter smaller than that of the lock ring accommodation groove is formed on the inner periphery of the receiving port on the far side from the lock ring accommodation groove. The small-diameter portion is designed so that the tip end of the insertion opening formed with the protrusion freely moves in the pipe axis direction between the lock ring and the rear end surface of the receiving port, so that the pipe joint can be expanded and contracted. It is formed to have a constant length in the tube axis direction.

[0004]

However, in such a conventional structure, a small diameter portion having a constant inner diameter is formed from the end edge of the lock ring receiving groove to the rear end of the receiving opening, so that the insertion opening is particularly preferable. If the projection of the insertion slot is located near the back end of the receiving slot by inserting the socket to the rear side of the receiving slot, this projection will be released when the receiving slot and the insertion slot try to bend each other. There is a problem that the inner surface of the small-diameter portion easily hits, and thus sufficient bending performance cannot be obtained.

Therefore, the present invention solves such a problem and makes it possible to impart sufficient bending performance between the receiving opening and the insertion opening even when the insertion opening is inserted to the far side of the receiving opening. With the goal.

[0006]

In order to achieve the above object, the present invention has a lock ring accommodating groove formed in the inner periphery of a receiving port, in which a lock ring which is divided in the circumferential direction is attached to accommodate the lock ring. An elastic ring that holds the lock ring in a centered state is arranged between the inner peripheral surface of the groove and the outer peripheral surface of the lock ring, and the insertion is performed on the outer periphery of the tip portion of the insertion opening inserted into the receiving opening. At the same time, the lock ring is elastically expanded so that it can pass through the inside of the lock ring toward the rear side of the socket, and after passing through, the lock ring is formed with an outer peripheral projection that can engage from the rear side of the socket. , An inner circumferential protrusion that backs up the lock ring is formed on the inner periphery of the receiving port on the back side of the lock ring accommodating groove, and on the inner periphery of the receiving port on the back side of the inner circumferential protrusion, A first inner peripheral surface having a diameter larger than that of the inner peripheral projection is formed. Between the inner peripheral surface and the inner circumferential projection of
A second inner peripheral surface having a diameter larger than the inner peripheral projection and smaller than the first inner peripheral surface is formed.

According to this structure, the first inner peripheral surface having a diameter larger than that of the inner peripheral projection for backing up the lock ring is formed on the inner side of the receiving opening with respect to the inner peripheral projection.
When the receiving opening and the insertion opening try to bend each other, the outer peripheral projection of the insertion opening hardly contacts the inner peripheral surface of the receiving opening, and thus the required bending performance is ensured.

Further, between the first inner peripheral surface and the inner peripheral protruding portion, a second inner peripheral surface having a diameter larger than that of the inner peripheral protruding portion and smaller than that of the first inner peripheral surface is formed. , When the outer peripheral protrusion approaches the inner peripheral protrusion of the receiving opening,
By restricting the movement of the outer peripheral projection by the second inner peripheral surface, it is possible to prevent excessive bending beyond necessity.

Since the second inner peripheral surface has a larger diameter than the inner peripheral protruding portion, a step portion is formed between the second inner peripheral surface and the inner peripheral protruding portion. For this reason, the outer peripheral projection of the insertion port is brought closer to the lock ring, and a liner is inserted between the tip of the insertion port and the rear end of the receiving port to prevent expansion and contraction between the receiving port and the insertion port. When laying a liner, one end of an elastic body, which is arranged between the outer circumference of the liner and the first and second inner circumferential surfaces and holds the liner in the centered state, is accommodated in the step portion. The elastic body is held at a predetermined position in a stable state.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In FIG. 1, reference numeral 1 designates a receiving port, in which a rubber sealing material 3 is arranged in a sealing material housing groove 2 on the inner periphery thereof. A lock ring housing groove 4 is formed on the inner periphery of the receiving port 1 on the back side of the seal material housing groove 2, and a lock ring 5 divided in the circumferential direction is housed in the lock ring housing groove 4. An elastic ring 6 made of rubber is interposed between the outer peripheral surface of the lock ring 5 and the inner peripheral surface of the lock ring housing groove 4, and the elastic ring 6 is bonded to the outer peripheral surface of the lock ring 5. . Reference numeral 8 denotes an insertion opening inserted into the receiving opening 1, and an outer peripheral projection 9 capable of engaging with the lock ring 5 from the rear side of the receiving opening is formed on the outer periphery of the tip portion thereof.

The side surface on the receiving opening side forming the lock ring accommodating groove 4 is formed as a tapered surface 11, and when the lock ring 5 is moved so as to slip out toward the opening side of the receiving opening 1, the outer peripheral edge of the lock ring 5 is formed. It is configured to engage with the tapered surface 11. A taper surface 12 is formed on the inner circumference of the receiving opening side portion of the lock ring 5, and a taper surface 13 is formed on the outer circumference of the distal end portion of the insertion opening 8.

An inner peripheral projection 15 for backing up the lock ring 5 is formed on the inner peripheral surface of the receiving port 1 on the inner side of the lock ring receiving groove 4. The inner diameter of the inner peripheral projection 15 is formed to be slightly larger than the outer diameter of the projection 9 at the tip of the insertion opening 8. The dimension of the inner circumferential projection 15 along the tube axis direction is formed so as to correspond to the dimension of the insertion opening 8 on the tip side of the outer circumferential projection 9 in the tube axis direction.

The inner peripheral projection 15 is configured to have a constant distance from the inner peripheral projection 15 to the rear end surface 16 of the receiving port 1.
Receptacle 1 on the back side from 5, ie near the back end face 16
A first inner peripheral surface 17 is formed on the inner periphery of the. The inner diameter of the first inner peripheral surface 17 is larger than the inner diameter of the inner peripheral projection 15. Further, a second inner peripheral surface 18 is formed between the first inner peripheral surface 17 and the inner peripheral protruding portion 15. The inner diameter of the second inner peripheral surface 18 is equal to the inner peripheral projection 15
Is larger than the inner diameter of the first inner peripheral surface 17 and smaller than the inner diameter of the first inner peripheral surface 17. The first inner peripheral surface 17 and the second inner peripheral surface 18 are each formed within a range of an appropriate length along the tube axis direction. Inner circumference protrusion 1
5 at the boundary between the second inner peripheral surface 18 and the corner 5
Are formed. The corner portion 19 is formed at an angle of 90 degrees.

At the time of joining the receiving port 1 and the insertion port 8, the sealing material 3 is housed in the sealing material housing groove 2 of the receiving port 1. Further, the lock ring 5 in which the elastic ring 6 is bonded to the outer periphery is mounted in the lock ring housing groove 4. Then, the lock ring 5 is held by the elastic ring 6 without being eccentric to the axial center of the receptacle 1.

In this state, the insertion opening 8 is inserted into the receiving opening 1. Then, first, the sealing material 3 is compressed around the outer periphery of the insertion opening 8, and a seal between the receiving opening 1 and the insertion opening 8 is secured. Further, since the lock ring 5 is held by the elastic ring 6 without being eccentric, it is possible to prevent a problem that the tip of the insertion opening 8 is caught by the lock ring 5 and cannot be smoothly inserted. When the insertion opening 8 is pushed in while the tip of the insertion opening 8 is engaged with the inner circumference of the lock ring 5, the tapered surface 13 at the outer circumference of the tip of the insertion opening 8 and the tapered surface 12 at the inner circumference of the lock ring 5. The lock ring 5 elastically expands its diameter together with the elastic ring 6 due to the interaction with, and the outer peripheral projection 9 of the insertion slot 8 easily passes through the inner periphery of the lock ring 5.

After the outer peripheral projection 9 has passed the lock ring 5, the lock ring 5 returns to its original state and fits securely on the outer periphery of the insertion slot 5. Therefore, the lock ring 5 and the outer peripheral projection 9 can be engaged with each other. When the protrusion 9 engages with the lock ring 5 by the pulling force acting on the insertion opening 8, the lock ring 5 is pressed against the outer peripheral surface of the insertion opening 8 by the action of the tapered surface 11, and the lock ring 5 and the outer peripheral projection 9
With this, a reliable engagement function can be obtained.

Since there is a constant distance from the lock ring 5 to the rear end surface 16 of the receiving port 1, the receiving port 1 and the insertion port 8 can freely expand and contract in the pipe axis direction within this range. Further, since the large-diameter first inner peripheral surface 17 is formed in the vicinity of the rear end surface 16 of the receiving opening 1, as shown by a phantom line in FIG. 1, the receiving opening 1 and the insertion opening 8 are formed at a large angle. It is possible to bend with. Specifically, this type of pipe joint has a critical bending angle of about 8
However, by forming the large-diameter first inner peripheral surface 17 in this way, the outer peripheral protrusion 9 of the insertion opening 8 can be bent to the first inner peripheral surface 17 even when bent to this limit refraction angle. It can be configured so as not to contact the peripheral surface 15. Therefore, even when an earthquake occurs, it is possible to prevent an accident such as damage to the pipe body due to the stress at the time of contact.

However, when the tip of the insertion slot 8 moves away from the rear end surface 16 of the receiving slot 1 and approaches the inner circumferential projection 15, the outer circumferential projection 9 of the insertion slot 8 is bent at that time.
If the inner diameter of the receiving port 1 at the portion where is present is large similarly to the first inner peripheral surface 17, bending will occur at an excessive angle exceeding the above-mentioned limit bending angle. Then, the sealing material 3 can no longer follow the bending, and the fluid in the tube may leak to the outside of the tube.

However, as described above, since the second inner peripheral surface 18 having a diameter smaller than that of the first inner peripheral surface 17 is formed in that portion, as shown in FIG. 2, this second inner peripheral surface 18 is formed. Face 18
As a result, the movement of the outer peripheral protrusion 9 of the insertion slot 8 is restricted, and the occurrence of excessive bending as described above can be prevented. Further, in the portion where the second inner peripheral surface 18 is formed, the wall thickness of the receptacle 1 can be made larger than that in the portion where the first inner peripheral surface 17 is formed. Since a predetermined thickness can be secured without increasing the outer diameter of 1, the weight can be reduced.

When the pipe is formed of a deformed pipe or the like, it is often necessary to prevent the separation prevention pipe joint from expanding and contracting. Therefore, for example, when joining the receiving end of the straight pipe and the insertion end of the deformed pipe which constitute the separation preventing pipe joint of the present invention, a liner 21 as shown in FIG. 3 is used.

In detail, as shown in the drawing, a cylindrical liner 21 is inserted in advance inside the portion corresponding to the first inner peripheral surface 17 and the second inner peripheral surface 18 of the receiving port, and then the receiving portion is received. Insert the insertion opening 8 into the opening 1. The inner diameter and the outer diameter of the liner 21 are formed so as to be the same as the inner diameter and the outer diameter of the insertion opening 8. Then, due to the presence of the liner 21, the outer peripheral projection 9 of the insertion slot 8 approaches the lock ring 5 and is positioned on the inner peripheral side of the inner peripheral projection 15, and one end of the liner 21 is located at the tip of the insertion slot 8. While facing each other, the other end faces the rear end surface 16 of the receiving port.

Therefore, the expansion and contraction between the receiving opening 1 and the insertion opening 8 are prevented, and the bending is similarly prevented.
Since the inner diameter of the liner 21 is aligned with the inner diameter of the insertion port 8, the presence of the liner 21 prevents the flow of the fluid in the pipe from being disturbed.

Between the outer peripheral surface of the liner 21 and the first and second inner peripheral surfaces 17 and 18, a rubber cylindrical centering member 22 is provided as an elastic body for holding the liner. . The centering member 22 has a rectangular cross section. Therefore, the centering member 22 fits into the corner portion 19 formed at the angle of 90 degrees at the boundary between the inner circumferential projection 15 and the second inner circumferential surface 18. This enables the centering member 22 to be correctly held in a predetermined position in a stable state.

[0024]

As described above, according to the present invention, an inner peripheral protrusion for backing up the lock ring is formed on the inner periphery of the receiving port on the inner side of the lock ring accommodating groove. Also, on the inner circumference of the receiving port on the back side, a first diameter larger than this inner circumference protrusion
An inner peripheral surface of the second inner peripheral surface of the first inner peripheral surface is formed between the first inner peripheral surface and the inner peripheral protruding portion. Since the inner peripheral surface is formed, the above first
By forming the inner peripheral surface of the socket, when the receiving opening and the insertion opening try to bend with respect to each other, the outer peripheral projection of the insertion opening does not easily come into contact with the inner peripheral surface of the receiving opening, and thus the required bending performance can be secured. it can. In addition, by forming the second inner peripheral surface, when the insertion opening comes out to some extent and the outer peripheral projection approaches the inner peripheral projection of the receiving opening, the movement of the outer peripheral projection is caused by the second inner peripheral surface. As a result of being restricted, it is possible to prevent the occurrence of excessive flexion. Further, since the second inner peripheral surface has a larger diameter than the inner peripheral protruding portion, a step portion can be formed between the second inner peripheral surface and the inner peripheral protruding portion, and the step portion forms the liner. The elastic body for holding can be held at a predetermined position in a stable state.

[Brief description of the drawings]

FIG. 1 is a sectional view of a separation prevention pipe joint according to the present invention.

FIG. 2 is a cross-sectional view showing a state in which the separation prevention pipe joint of FIG. 1 is bent.

3 is a cross-sectional view showing a state in which a liner for preventing expansion and contraction is arranged in the separation preventing pipe joint of FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Receptacle 5 Lock ring 6 Elastic ring 8 Insertion slot 9 Outer peripheral protrusion 15 Inner peripheral protrusion 17 First inner peripheral surface 18 Second inner peripheral surface 21 Liner

Claims (1)

[Claims] 1. A lock ring accommodating groove formed on the inner periphery of a receiving port is fitted with a lock ring divided in the circumferential direction, and between the inner peripheral surface of the lock ring accommodating groove and the outer peripheral surface of the lock ring. , An elastic ring for holding the lock ring in a centered state is arranged, and the lock ring is elastically expanded in diameter at the time of the insertion on the outer periphery of the tip end portion of the insertion port inserted into the receiving port. Of the receiving port on the inner side of the lock ring accommodating groove, the outer peripheral projection capable of engaging from the back side of the receiving port is formed on the lock ring after passing through the inside of the receiving port. An inner peripheral protrusion that backs up the lock ring is formed on the inner periphery, and a first inner periphery having a larger diameter than the inner peripheral protrusion is formed on the inner periphery of the receptacle on the back side of the inner peripheral protrusion. A surface is formed, and between the first inner peripheral surface and the inner peripheral protrusion, the inner peripheral protrusion is formed. A separation prevention pipe joint, characterized in that a second inner peripheral surface having a diameter larger than that of the first inner peripheral surface is formed.