JP3278563B2 - Captive fittings - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a slip-off prevention pipe joint, and more particularly to a slip-on type slip-off prevention pipe joint capable of joining a socket to a socket by inserting a socket into the socket.

[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. Some slip-on type pipe joints have a detachment preventing function.

[0003] In this disengagement prevention pipe joint, a lock ring accommodating groove is formed on the inner side of the receiving port at a position deeper than the seal material accommodating groove, and a lock ring divided in a circumferential direction is attached to the lock ring accommodating groove. ing. A rubber ring for holding 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 projection is formed on the outer periphery of the distal end of the insertion port so as to engage with the lock ring from the back side of the reception port. A small-diameter portion having a diameter smaller than that of the lock ring housing groove is formed on the inner periphery of the receiving port on the back side of the lock ring housing groove. The small-diameter portion is designed so that the distal end of the insertion port with the projection is freely moved in the pipe axis direction between the lock ring and the rear end face of the receiving port, so that the pipe joint is provided with expansion and contraction performance. It is formed to have a certain 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 edge of the lock ring accommodating groove to the inner end of the socket. If the projection of the insertion port is located near the rear end of the reception port due to the insertion of the projection to the back side of the reception port, when the reception port and the insertion port try to bend with each other, this projection There is a problem that the inner surface of the small-diameter portion is easily hit, so that sufficient bending performance cannot be obtained.

Accordingly, the present invention has been made to solve such a problem and to provide a sufficient bending performance between the socket and the insertion port even when the insertion port is inserted to the inner side of the receiving port. With the goal.

[0006]

SUMMARY OF THE INVENTION In order to achieve the above object, according to the present invention, a lock ring accommodating in the circumferential direction is mounted in a lock ring accommodating groove formed on an inner periphery of a receiving port. An elastic ring for holding 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 outer periphery of a distal end portion of the insertion port inserted into the receiving port is provided. At times, the lock ring is elastically enlarged in diameter so that the inside of the lock ring can pass through the inside of the socket, and after passing through, the lock ring has an outer peripheral projection that can be engaged from the inside of the socket. An inner peripheral projection for backing up the lock ring is formed on the inner periphery of the receiving port deeper than the lock ring housing groove. 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 protrusion and smaller than the first inner peripheral surface is formed.

According to such a configuration, 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 back side of the receiving port with respect to the inner peripheral projection.
When the receiving opening and the insertion opening try to bend with each other, the outer peripheral projection of the insertion opening hardly hits the inner peripheral surface of the receiving opening, so that required bending performance is secured.

Further, a second inner peripheral surface having a diameter larger than the inner peripheral protrusion and smaller than the first inner peripheral surface is formed between the first inner peripheral surface and the inner peripheral protrusion. When the insertion hole comes out to some extent and its outer peripheral protrusion approaches the inner peripheral protrusion of the receiving port,
By restricting the movement of the outer peripheral projection by the second inner peripheral surface, it is possible to prevent an excessive bending from occurring.

Since the second inner peripheral surface has a larger diameter than the inner peripheral projection, a step is formed between the second inner peripheral surface and the inner peripheral projection. 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 distal end of the insertion port and the rear end of the receiving port to prevent expansion and contraction between the receiving port openings. When one wants to lay, one end of an elastic body that is arranged between the outer periphery of the liner and the first and second inner peripheral surfaces and holds the liner in a centered state is accommodated in this step. Thus, the elastic body is held at a predetermined position in a stable state.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In FIG. 1, reference numeral 1 denotes a receiving port, and a rubber sealing material 3 is disposed in a sealing material receiving 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 hole to be inserted into the receptacle 1. An outer peripheral projection 9 which can be engaged with the lock ring 5 from the back side of the receptacle is formed on the outer periphery of the distal end.

The side surface on the opening side of the receiving opening forming the lock ring receiving groove 4 is formed as a tapered surface 11, and when the lock ring 5 moves so as to come out to the opening side of the receiving opening 1, the outer peripheral edge of the lock ring 5 is moved. It is configured to engage with the tapered surface 11. A tapered surface 12 is formed on the inner periphery of the receiving ring opening side portion of the lock ring 5, and a tapered surface 13 is formed on the outer periphery 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 at a position deeper than the lock ring housing groove 4. The inner diameter of the inner peripheral projection 15 is slightly larger than the outer diameter of the projection 9 at the tip of the insertion opening 8. The dimension of the inner peripheral projection 15 along the tube axis direction is formed corresponding to the dimension of the insertion port 8 on the distal end side than the outer peripheral projection 9 in the tube axis direction.

The inner projection 1 is configured to have a certain distance from the inner projection 15 to the inner end face 16 of the socket 1.
5 on the back side, that is, near the back end face 16
A first inner peripheral surface 17 is formed on the inner periphery of the first inner peripheral surface. The inner diameter of the first inner peripheral surface 17 is larger than the inner diameter of the inner peripheral projection 15. In addition, a second inner peripheral surface 18 is formed between the first inner peripheral surface 17 and the inner peripheral protrusion 15. The inner diameter of the second inner peripheral surface 18 is
The inner diameter of the first inner peripheral surface 17 is larger 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 in a range of an appropriate length along the pipe axis direction. Inner circumference protrusion 1
A corner portion 19 is provided at a boundary portion between the first inner peripheral surface 5 and the second inner peripheral surface 18.
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 stored in the sealing material receiving groove 2 of the receiving port 1. Further, the lock ring 5 having the elastic ring 6 adhered 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 with respect to the axis of the socket 1.

In this state, the insertion port 8 is inserted into the reception port 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 inserted smoothly. When the insertion port 8 is pushed in a state where the front end of the insertion port 8 is engaged with the inner circumference of the lock ring 5, the tapered surface 13 on the outer circumference of the front end of the insertion port 8 and the tapered surface 12 on the inner circumference of the lock ring 5. The lock ring 5 elastically expands in diameter together with the elastic ring 6 due to the interaction with the elastic ring 6, and the outer peripheral projection 9 of the insertion opening 8 easily passes through the inner periphery of the lock ring 5.

After the outer peripheral projection 9 has passed through the lock ring 5, the lock ring 5 returns to its original state, and is securely fitted to the outer periphery of the insertion port 5. For this reason, 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 due to the withdrawal 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 are engaged.
And a reliable relationship with the separation prevention function can be obtained.

Since there is a certain distance from the lock ring 5 to the rear end face 16 of the socket 1, the socket 1 and the insertion port 8 can freely expand and contract in the tube axis direction within this range. In addition, since a large-diameter first inner peripheral surface 17 is formed near the back end face 16 of the receptacle 1, the receptacle 1 and the insertion port 8 are formed at a large angle as shown by a virtual line in FIG. 1. Can be bent. Specifically, this type of pipe joint has a critical bending angle of about 8
Although the first inner peripheral surface 17 having a large diameter is formed as described above, the outer peripheral projection 9 of the insertion opening 8 can be moved to the first inner peripheral surface even when bent to the 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 breakage of the pipe body based on the stress at the time of the contact.

However, if the distal end of the insertion opening 8 bends away from the inner end surface 16 of the receptacle 1 and approaches the inner peripheral projection 15, then the outer peripheral projection 9 of the insertion opening 8 will be bent at that time.
If the inner diameter of the receiving port 1 in the portion where the groove is present is as large as the first inner peripheral surface 17, bending at an excessive angle exceeding the above-described limit bending angle occurs. Then, the sealing member 3 can no longer follow the bending, and the fluid in the pipe may leak out of the pipe.

However, as described above, since the second inner peripheral surface 18 having a smaller diameter than the first inner peripheral surface 17 is formed in that portion, as shown in FIG. Face 18
As a result, the movement of the outer peripheral projection 9 of the insertion opening 8 is restricted, and the occurrence of excessive bending as described above can be prevented. In addition, the thickness of the receiving port 1 can be made larger in the portion where the second inner peripheral surface 18 is formed than in the portion where the first inner peripheral surface 17 is formed. It is possible to secure a predetermined thickness without increasing the outer diameter of 1, and it is possible to reduce its weight.

In the case of forming a pipeline with a deformed pipe or the like, it is often necessary to prevent expansion and contraction or bending of the separation preventing pipe joint. Therefore, for example, in a case where a straight pipe receiving port and a modified pipe inserting port which constitute the detachment preventing pipe joint of the present invention are joined, a liner 21 as shown in FIG. 3 is used.

More specifically, as shown in the drawing, a cylindrical liner 21 is inserted in advance into a portion corresponding to the first inner peripheral surface 17 and the second inner peripheral surface 18 of the receiving port, and then the receiving port is inserted. The insertion port 8 is inserted into the mouth 1. The inner diameter and the outer diameter of the liner 21 are formed so as to match the inner diameter and the outer diameter of the insertion opening 8. Then, due to the presence of the liner 21, the outer peripheral protrusion 9 of the insertion opening 8 approaches the lock ring 5 and is positioned on the inner peripheral side of the inner peripheral protrusion 15, and one end of the liner 21 is located at the tip of the insertion opening 8. The other end faces the rear end face 16 of the socket.

For this reason, expansion and contraction between the receiving port 1 and the insertion port 8 are prevented, and also bending is prevented.
Since the inner diameter of the liner 21 is aligned with the inner diameter of the insertion opening 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, 18, a rubber centering member 22 made of rubber is provided as an elastic body for holding the liner. . The centering member 22 has a rectangular cross section. For this reason, the centering member 22 fits into the corner portion 19 formed at an angle of 90 degrees at the boundary between the inner peripheral projection 15 and the second inner peripheral surface 18. This makes it possible to correctly hold the centering member 22 at a predetermined position in a stable state.

[0024]

As described above, according to the present invention, an inner peripheral projection for backing up the lock ring is formed on the inner periphery of the receiving port on the back side of the lock ring receiving groove. Also on the inner periphery of the receiving port on the back side, a first
Is formed between the first inner circumferential surface and the inner circumferential protrusion, and a second diameter having a larger diameter than the inner circumferential protrusion and a smaller diameter than the first inner circumferential surface is formed between the first inner circumferential surface and the inner circumferential protrusion. Since the inner peripheral surface is formed, especially the first
By forming the inner peripheral surface of the opening, when the receiving port and the insertion port try to bend with each other, the outer peripheral projection of the insertion port is less likely to hit the inner peripheral surface of the receiving port, so that the required bending performance can be secured. it can. In addition, by forming the second inner peripheral surface, when the insertion hole comes out to some extent and the outer peripheral protrusion approaches the inner peripheral protrusion of the receiving port, the movement of the outer peripheral protrusion is caused by the second inner peripheral surface. Is regulated, it is possible to prevent the occurrence of excessive bending. Further, since the second inner peripheral surface is larger in diameter than the inner peripheral protrusion, a step can be formed between the second inner peripheral surface and the inner peripheral protrusion, and the liner is formed by the step. The holding elastic body can be held at a predetermined position in a stable state.

[Brief description of the drawings]

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

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

FIG. 3 is a cross-sectional view showing a state in which a liner for preventing expansion and contraction is arranged on the separation-preventing pipe joint of FIG. 1;

[Explanation of symbols]

 DESCRIPTION OF REFERENCE NUMERALS 1 receiving port 5 lock ring 6 elastic ring 8 insertion opening 9 outer peripheral projection 15 inner peripheral projection 17 first inner peripheral surface 18 second inner peripheral surface 21 liner

Claims (1)

(57) [Claims] 1. A lock ring, which is divided in a circumferential direction, is mounted in a lock ring accommodating groove formed on an inner periphery of a receiving port, and a lock ring is provided between an inner peripheral surface of the lock ring accommodating groove and an 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 at the time of the insertion on the outer periphery of the distal end portion of the insertion hole to be inserted into the socket. Can pass through the inside of the receiving port to the back side of the receiving port, and after passing through, form an outer peripheral projection that can engage with the lock ring from the receiving port back side, and An inner peripheral projection for backing up the lock ring is formed on the inner periphery, and a first inner periphery having a diameter larger than that of the inner peripheral projection is formed on the inner periphery of the receiving port on the back side of the inner peripheral projection. A surface is formed between the first inner peripheral surface and the inner peripheral protrusion. A detachment prevention pipe joint, wherein a second inner peripheral surface having a larger diameter than the first inner peripheral surface is formed.