JPH11201347A - Pipe fittings - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To make it possible to screw a push ring into a pipe to prevent the pipe from coming off only when the length of insertion of the pipe into a connection port is sufficiently long. Prevents pipes from being pulled out during pipe connection work. SOLUTION: A joint body 1 having a connection port 12, an elastically expandable and contractible retaining ring 4, a pressing ring 3,
And a retaining ring support 5. Between the receiving surface 16 provided on the joint body 1 side and the pressing surface 35 provided on the pressing wheel 3 side, the retaining ring 4 in an expanded state supported by the retaining ring support 5 is provided. When the retaining ring support 5 is pushed out of the retaining ring 4 by the tube, the retaining ring 4 is reduced in diameter by its own elasticity, and the initial biting teeth 42 bite into the outer periphery of the tube.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pipe joint, and more particularly to a pipe joint having a function of preventing a pipe from coming off by engaging a tooth provided on a retaining ring with the outer periphery of the pipe.

[0002]

2. Description of the Related Art Many pipe joints of this type include a joint body having an external thread, a press ring having an internal thread screwed into the external thread, a retaining ring capable of reducing the diameter, and the like. In many cases, the female screw of the push ring is screwed into the male screw to connect the joint body and the push ring, and the retaining ring is held therein to assemble the three members integrally and carry the pipe to the piping construction site.

[0003]

SUMMARY OF THE INVENTION The applicant of the present application has
In such a pipe joint as described above, it is possible to screw the push ring only when the pipe is inserted into the connection port of the joint body by a sufficient insertion length, and if the push ring can be screwed in, The retaining ring is surely exerted by the retaining ring on the pipe inserted into the connection port of the main body, and if the insertion length of the pipe to the connection port is insufficient, the press ring cannot be screwed. A pipe joint which exerts an effect of being able to recognize the shortage of the insertion length of the pipe has been proposed.

In this pipe joint, a tubular retaining ring support is fitted in a retaining ring provided inside a joint body and a press ring which are screwed and connected to each other, and a pipe inserted through the press ring is used. When the retaining ring support is pushed out of the retaining ring, the retaining ring can be reduced in diameter only when the retaining ring is reduced in diameter, and the pressing ring can be screwed in while reducing the diameter of the retaining ring. On the other hand, the diameter of the retaining ring is prevented by the retaining ring support unless the retaining ring support is pushed out of the retaining ring by the tube, so that the retaining ring support is pushed from the retaining ring by the tube. Unless it is released, the operation of screwing the pressing ring while reducing the diameter of the retaining ring cannot be performed.

[0005] With this pipe joint, as long as the press ring can be screwed into the pipe joint, the retaining action of the retaining ring to the pipe inserted into the connection port of the joint body is surely ensured. When the insertion length of the pipe with respect to the connection port is insufficient, it is not possible to screw in the pressing ring, and it is possible to recognize the shortage of the insertion length of the pipe, This has the advantage that the tube can be securely connected in a retaining state.

[0006] However, at the construction site of this pipe joint, after the retaining ring support is pushed out of the retaining ring by the pipe inserted into the push ring, the pipe is pulled out of the retaining ring before the pushing ring is screwed. If the tube is pulled out of the retaining ring in such a way, even if the tube is inserted again,
In other words, as long as the press ring can be screwed in, the function of surely exerting the retaining action by the retaining ring on the pipe inserted into the connection port of the joint body is impaired.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and in a pipe joint having a retaining ring support for restricting whether or not a press ring is screwed into a pipe, particularly a resin pipe (resin coating). It is an object of the present invention to provide a pipe joint that can prevent a situation in which the pipe is pulled out of the retaining ring after the retaining ring support is extruded from the retaining ring by using the retaining ring. .

[0008]

According to a first aspect of the present invention, there is provided a pipe joint having a tubular joint body having a concentrically protruding connection port to which a pipe is externally fitted; A retaining ring that can be diametrically secured, a push ring that can be screwed to the joint body and through which the tube is inserted, a ring portion into which the distal end of the tube that is inserted through the push ring can be inserted, and a radial portion of the ring portion And a contact portion with which the distal end surface of the tube inserted into the ring portion abuts in the direction, and is fitted inside the retaining ring to expand the retaining ring against its elasticity. A retaining ring support that supports the joint in a state where the joint body is provided with a protrusion concentrically protruding around the connection port, between the protrusion and the connection port. The tip of the above-mentioned retaining ring support and the tube inserted into the above-mentioned loop portion of the retaining ring support Is formed, a receiving surface is formed on the end face of the protruding portion with which one end of the retaining ring contacts, and the other end of the retaining ring is pressed against the pressing ring. And a pressing surface for
The receiving surface and the pressing surface are formed in a tapered shape whose diameter gradually increases as they approach each other in a state where the pressing ring is screwed into the joint body, and the receiving surface of the projecting portion and the pressing ring are formed. On the inner peripheral side of the retaining ring disposed between the retaining ring and the pressing surface, the retaining ring support body fitted inside the retaining ring is pushed out of the retaining ring by the tube. An initial biting tooth that engages with the outer periphery of the tube when the retaining ring is reduced in diameter by its own elasticity; and the pressing surface of the pressing ring screwed to the receiving surface of the protruding portion and the joint body. When the retaining ring is reduced in diameter while sliding between the receiving surface and the pressing surface due to the pressure, the toothed teeth are provided to bite into the outer periphery of the pipe.

In the present invention, when the tube is not inserted, the retaining ring is supported by the retaining ring support in an expanded state.

When the tube is inserted and the retaining ring support is pushed out of the retaining ring, the retaining ring is reduced in diameter by its own elasticity, and its initial biting teeth are hooked on the outer periphery of the tube. It is desirable that the hooking state at this time is a state in which the initial biting teeth slightly bite into the outer periphery of the pipe, but even if the biting is not performed, the initial biting teeth are aligned with the axis of the pipe with respect to the outer circumference. It may be in a state where it is merely hung so as not to easily slide in the direction. If the initial biting teeth are hung on the outer circumference of the tube in this way, even if the tube is pulled in the withdrawal direction and moved in the withdrawal direction before screwing the pressing ring, the retaining ring that moves with the tube will not move. The tube comes out of contact with the pressing surface of the pressing wheel and is prevented from being pulled out. In particular, when the retaining ring is strongly pressed against the pressing surface of the press ring, the retaining surface receives a force in the diameter-reducing direction because the pressing surface is formed in a tapered shape, and the initial biting teeth are caused by the force. In addition, bite into the tube to prevent it from falling off.

On the other hand, after the tube is inserted and the retaining ring support is pushed out of the retaining ring, when the pressing ring is screwed without being pulled in the pulling direction, the pressing surface of the pressing ring and the receiving surface of the joint body are received. The retaining ring is clamped between the surfaces, and the retaining ring slides between the receiving surface and the pressing surface and is reduced in diameter, and the teeth of the retaining ring bite into the outer periphery of the pipe. Stop the tube.

According to a second aspect of the present invention, there is provided a pipe joint according to the first aspect.
In the above described, the retaining ring has the initial biting teeth on the inner circumference on the other end side, and has the protruding teeth on the inner circumference on one end side than the initial biting teeth,
The diameter of the other end of the retaining ring pressed by the pressing surface of the pressing ring is larger than the diameter of one end of the retaining ring abutting on the receiving surface of the protrusion, and A pressing portion for pressing the other end of the ring without sliding the ring is provided at the small-diameter end of the pressing surface.

According to the present invention, when the retaining ring is pressed between the pressing portion of the pressing wheel and the receiving surface of the projecting portion to press the retaining ring, the retaining ring comes into contact with the tapered receiving surface of the projecting portion. Only one end of the slide ring is reduced in diameter. Therefore, the initial biting teeth on the other end side of the retaining ring do not bite into the outer circumference of the tube, which means that
This helps to prevent a situation in which the pipe is torn at the bite portion of the initial bite teeth.

According to a third aspect of the present invention, there is provided a pipe joint according to the second aspect.
In the above-mentioned, the small-diameter side end of the receiving surface and the end of the outer peripheral surface of the tube end insertion space are connected to each other, and the screwing allowance of the pressing ring into the joint body is determined by the pressing portion. It has a length that allows one end of the retaining ring to be pushed into the tube end insertion space.

With this configuration, the retaining ring is pressed by the receiving surface of the projecting portion and the pressing surface of the pressing ring to reduce the diameter, and then fits into the tube end insertion space. The diameter becomes blocked by the protrusion. In this state, even if the pressing ring is loosened, the retaining ring does not expand in diameter, so that the retaining function of the retaining ring is more reliably exhibited.

According to a fourth aspect of the present invention, in the pipe joint according to any one of the first to third aspects, the opening angle of the receiving surface and the opening angle of the pressing surface are the same. It is stipulated in.

According to the present invention, there is no occurrence of a state in which the retaining ring, which has been reduced in diameter by being pressed between the receiving surface of the projection and the pressing surface of the pressing ring, pushes the tube in the insertion direction.

According to a fifth aspect of the present invention, in the pipe joint according to any one of the first, second, third, and fourth aspects, the pipe joint is provided on the outer peripheral side of the connection port. That is, a protrudable tooth is provided on the inner periphery. According to this, since the protruding teeth bite into both the inside and the outside of the tube wall, the retaining function is more reliably exhibited.

[0019]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is an exploded partial longitudinal side view of an embodiment of a pipe joint according to the present invention, FIG. 2 is a partial cross-sectional view of a retaining ring, and FIGS. 7 to 10 are partial longitudinal side views showing a procedure for installing a pipe joint, and FIG. 11 is a partial longitudinal side view showing an operation when a pipe is pulled in a drawing direction during construction. It is.

In the pipe joint shown in FIG.
Is made of metal and has a locking portion 1 for a tool such as a wrench.
1, a tubular connection port 12 to which a pipe (not shown) is fitted by external connection, a cylindrical projection 13 concentrically protruding around the connection port 12, and the like; The connection port 12 protrudes from the protrusion 13, and the connection port 12 is smaller in diameter than the protrusion 13. A tube end insertion space 14 is formed between the connection port 12 and the protrusion 13. Further, a plurality of saw-toothed teeth 15 are formed in a ring shape at the axial center of the outer periphery of the connection port 12. Further, the protruding portion 13 has a tapered shape in which the diameter thereof is gradually reduced toward the distal end as it approaches the tube end insertion space 14, and the small diameter side end is continuously provided to the end of the outer peripheral surface 17 of the tube end insertion space 14. And a male screw 18 on the outer periphery thereof.

An annular groove 19 is formed at an intermediate portion in the axial direction of the male screw forming area of the joint body 1, and the male screw 18 is formed by this annular groove 19 on the short first screw portion 18 a on the near side of the annular groove 19 and its annular shape. Long second screw portion 1 on the back side of groove 19
8b. The ring body 2 is inserted into the annular groove 19.
Are held in a fitted state. As shown in FIG.
The ring body 2 is a synthetic resin molded body formed in a C-shape by removing one part in the circumferential direction, and its front end face 21 is formed at right angles to the axis, while its outer peripheral part is formed. Is formed with a tapered sliding surface 22 having a smaller diameter toward the rear side. While the ring body 2 protrudes from the annular groove 19 as shown in FIG. 1 in its natural state, it is accommodated in the annular groove 19 by being reduced in diameter against its elasticity. I have.

The press ring 3 is made of metal and has a female screw 31 in the front half of the inner peripheral portion thereof which can be screwed to the male screw 18 of the joint body 1, and has an end portion of the female screw 31 and an inner portion adjacent to the end portion. A stepped engagement portion 33 is provided at the boundary with the peripheral surface 32. The front end of the press wheel 3 is provided with a tapered action portion 34 that extends forward. Further, the inner surface of the rear wall of the pressing wheel 3 is formed in a tapered pressing surface 35 inclined forward and wide, and a pressing portion 36 is provided at a small-diameter end of the pressing surface 35. The opening angle of the pressing surface 35 is the same as the receiving surface 1 described above.
6, and is preferably 45 degrees.

The retaining ring 4 is formed so as to be able to expand and contract in diameter by an elastic ring member in which one portion in the circumferential direction is omitted, and as shown in an enlarged manner in FIG. In the illustrated example, the teeth 41 and the initial bite teeth 42 are formed in a ring shape. The retaining ring 4 is provided with the protruding teeth 41 on the inner periphery on one end side, the initial bite teeth 42 on the inner periphery on the other end side, and the diameter of the other end 44. Is larger than the diameter of the one end 43.

The retaining ring support 5 has a short cylindrical ring portion 51 and a ring-shaped contact portion 52 provided at the front end of the ring portion 51 in an inner flange shape. The inner diameter of the retaining ring 4 in the natural state is smaller than the outer diameter of the ring portion 51 of the retaining ring support 5. More specifically, the inner diameter of the retaining ring 4 in a natural state is
It is slightly smaller than the outer diameter of the tube 6 described later. The retaining ring support 5 has an outer diameter and an inner diameter that can be inserted into the tube end insertion space 14.

The pipe joint shown in FIG. 1 is assembled as shown in FIGS.

First, the first male screw 18 on the joint body 1 side
The female thread 31 of the press wheel 3 is screwed into the screw portion 18a at the beginning, and the press wheel 3 is temporarily fastened to the joint body 1. At this time, the retaining ring 4 is provided between the pressing surface 35 of the pressing ring 3 and the receiving surface 16 on the joint body 1 side, and the ring portion 51 of the retaining ring support 5 is provided inside the retaining ring 4. Mated. For this reason, the retaining ring 4 is supported by the retaining ring support 5 in a state where the diameter thereof is expanded against its elasticity.

As shown in FIG. 3, after the push ring 3 is temporarily fastened to the joint body 1, the female screw 31 of the push ring 3 is connected to the first body 31 on the joint body 1 side.
As the screw is screwed into the screw portion 18a, as shown in FIG. 4, the action portion 34 of the press ring 3 slides on the sliding surface 22 of the ring body 2 projecting from the annular groove 19. For this reason, the ring body 2 is gradually reduced in diameter as the push ring 3 advances in the direction of the arrow a, and the internal thread 31 of the push ring 3 rides on the ring body 2 as shown in FIG. Housed within. FIG.
When the press ring 3 is further screwed in from the state shown in FIG. 6, the female screw 31 of the press ring 3 moves over the ring body 2 as shown in FIG. When the entire female screw 31 of the push ring 3 is shifted to the second threaded portion 18b in this way, the ring body 2 returns to a natural state due to its own elasticity and projects from the annular groove 19, and the push ring 3 is attached to the front end face 21 of the ring body 2. Are engaged in the axial direction.

Thus, the assembly of the pipe joint is completed.
In the thus assembled pipe joint, when the press ring 3 is turned in the reverse direction to retract the female screw 31 with respect to the second thread portion 18b of the male screw 18 of the joint body 1, the press ring 3
Is engaged with the front end face 21 of the ring body 2, so that the pressing wheel 3 is prevented from retreating. Therefore, the pressing wheel 3 and the joint body 1 cannot be disassembled. Due to this, after the assembled pipe joint is carried into the pipe construction site, the pipe joint is inadvertently disassembled and the retaining ring 4 or the like falls off and is lost. There is no risk of not being performed. Note that if the pressing ring 3 is forcibly retracted, the ring body 2 is broken, and if the ring body 2 is broken in such a manner, the pressing ring 3 can be removed from the joint body 1.

In FIGS. 4, 5 and 6, the arrow a indicates the pressing wheel 3.
Represents the forward direction by screwing in.

Next, a procedure for connecting the pipe 6 made of a synthetic resin pipe such as a polyethylene pipe will be described with reference to FIGS.

As shown by an arrow b in FIG. 7 or FIG. 8, the distal end 61 of the tube 6 inserted through the pressing ring 3 is inserted into the loop 51 of the retaining ring support 5, and the distal end 62 of the tube 6 is removed. The retaining ring support 5 is pushed out of the retaining ring 4 by pushing the contact portion 52 of the retaining ring support 5, and is pushed into the tube end insertion space 14, and the diameter of the retaining ring 4 is reduced by the retaining ring support 5. The restriction action is released. When the action of restricting the diameter of the retaining ring 4 by the retaining ring support 5 is released in this manner, the retaining ring 4 is reduced in diameter by its own elasticity, and the initial biting teeth 42 are hooked on the outer periphery of the pipe 6. Is stopped. It is desirable that the hooking state at this time is a state in which the initial biting teeth 42 bit a little into the outer periphery of the pipe 6. It may be in a state of being merely hung to the extent that it does not easily slide in the axial direction.

When the initial biting teeth 42 are hung on the outer periphery of the tube 6, the tube 6 is pulled out in the drawing direction as indicated by an arrow c in FIG. Even if it moves in the direction, the other end portion 44 of the retaining ring 4 that moves together with the tube 6 abuts against the pressing surface 35 of the pressing wheel 3 to prevent the tube 6 from being pulled out. In particular, when the retaining ring 4 is strongly pressed against the pressing surface 35 of the pressing wheel 3, the retaining surface 4 receives a force in the diameter reducing direction because the pressing surface 35 is formed in a tapered shape. The initial biting teeth 42 further bite into the tube 6 to reliably prevent it from falling off.

As described above, the retaining ring support 5
When the pressing ring 3 is screwed in as shown by an arrow a in FIG.
Is pressed against the other end 44 of the retaining ring 4, and the retaining ring 4 is pushed in. Therefore, the retaining ring 4 is pressed by the receiving surface 16 of the projection 13 and the pressing surface 33 of the pressing ring 3. The diameter is reduced while sliding on the receiving surface 16 and the pressing surface 33. When the other end 44 of the retaining ring 4 is axially pressed by the pressing portion 36 of the pressing wheel 3 as shown in FIG.
Only the one end 43 of the retaining ring 4 that slides in contact with the tapered receiving surface 16 is reduced in diameter. Therefore, as shown in the figure, the initial biting teeth 42 on the other end 44 side of the retaining ring 4 do not bite into the outer periphery of the pipe. Therefore, even if the pipe 6 is strongly pulled in the pulling-out direction, a situation in which the pipe 6 is torn at the biting portion of the initial biting teeth 42 does not occur.

After the end 43 of the retaining ring 4 has been reduced in diameter to the small diameter end of the receiving surface 16, when the pressing ring 3 is further screwed in as indicated by an arrow a in FIG. 4 is pushed into the tube end insertion space 14. At this time, the retaining ring 4 is attached to the outer periphery of the distal end 61 of the pipe 6.
Of the connection port portion 12 bites into the inner periphery of the distal end portion 61 of the tube 6.

In the above-described pipe joint, in the pipe joint assembled as shown in FIG. 6, the loop 51 of the retaining ring support 5 is fitted inside the retaining ring 4, so that The diameter of the retaining ring 4 is prevented from being reduced by the retaining ring support 5. Therefore, the diameter of the retaining ring 4 cannot be reduced. Therefore, even if the pressing ring 3 is screwed in and pressed between the pressing surface 35 and the receiving surface 16 of the projection 13, it is impossible to screw the pressing ring 3 after the pressing.

The pressing surface 35 and the receiving surface 16
Have the same opening angle. Therefore, the retaining ring 4, which is gradually reduced in diameter by being pressed between the pressing surface 35 and the receiving surface 16, does not move in the axial direction. Therefore, even if the teeth 41 of the retaining ring 4 bite into the outer periphery of the distal end portion 61 of the tube 6, the tube 6 is not pushed and moved in the insertion direction. Accordingly, the teeth 41 of the retaining ring 4 bite into the outer periphery of the distal end portion 61 of the tube 6 without slipping, and the retaining action of the retaining ring 4 is reliably exhibited. Therefore, even if the tube 6 is completely inserted into the end of the tube end insertion space 14, a reliable retaining action is exhibited.

When the retaining ring 4 is inserted into the tube end insertion space 14 as shown in FIG. 10, the protrusion 13 prevents the diameter of the retaining ring 4 from expanding. Therefore, even if the pressing ring 3 is loosened, the retaining ring 4 does not expand in diameter, so that the retaining function of the retaining ring 4 is more reliably exerted.

As can be seen from the above description, in the above-mentioned pipe joint, when the press ring 3 can be screwed in, the tip 61 of the pipe 6 is always inserted into the pipe end insertion space 14, and the retaining ring support 5 is also formed. It is pushed into the tube end insertion space 14. Therefore, as long as the press ring 3 can be screwed in, the retaining action by the retaining ring 30 can be applied to the pipe 6 which is externally fitted by a sufficient insertion length into the connection port portion 12. . On the other hand, when the insertion length of the pipe 6 into the connection port 12 is insufficient, the retaining ring support 5 is not pushed out of the retaining ring 4 by the pipe 6, so that the pressing ring 3 Can not be screwed.

[0039]

According to the pipe joint of the present invention, as long as the press ring can be screwed in, the retaining ring can be prevented by the retaining ring for the pipe which is externally fitted into the connection port by a sufficient insertion length. Is surely exhibited. In other words, only when the tip of the pipe is inserted into the connection port by a sufficient length, the retaining ring can be screwed in to exert the retaining action of the retaining ring. Is reliably prevented. Also, even before screwing in the push ring, if the tube is inserted and the retaining ring support is pushed out of the retaining ring, the initial biting teeth of the retaining ring will be hooked on the outer circumference of the tube and the tube will be pulled out. Since the stop is performed, even if the pipe once inserted during the pipe connection operation is accidentally pulled out, the pulling out is surely prevented.

[Brief description of the drawings]

FIG. 1 is an exploded partial longitudinal side view of an embodiment of a pipe joint of the present invention.

FIG. 2 is a partial sectional view of a retaining ring.

FIG. 3 is a partial vertical sectional side view showing an initial state of assembly of the pipe joint.

FIG. 4 is a partial vertical sectional side view showing an intermediate state of the pipe joint assembly.

FIG. 5 is a partial longitudinal sectional side view showing an intermediate state of assembling the pipe joint.

FIG. 6 is a partial vertical cross-sectional side view showing a completed state of the assembly of the pipe joint.

FIG. 7 is a partial vertical cross-sectional side view showing a procedure for installing a pipe joint.

FIG. 8 is a partial longitudinal sectional side view showing a procedure for installing a pipe joint.

FIG. 9 is a partial vertical cross-sectional side view showing a procedure for installing a pipe joint.

FIG. 10 is a partial vertical cross-sectional side view showing a procedure for installing a pipe joint.

FIG. 11 is a partial vertical sectional side view showing an operation when a pipe is pulled in a drawing direction during construction.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Joint main body 3 Pressing ring 4 Retaining ring 5 Retaining ring support 6 Tube 12 Connection port 13 Projection part 14 Tube end insertion space 15 Tooth 16 Receiving surface 35 Press surface 36 Pressing part 41 Tooth 42 Initial biting tooth 43 Prevention One end of the ring 44 The other end of the retaining ring 51 Ring part 52 Contact part 61 Tip part of pipe 62 Tip face of pipe

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Yuji Kishimoto One day at 153 Taji Yonemachi, Kishiwada City, Osaka Prefecture Inside of Nippon Steel Pipe Fitting Co., Ltd. (72) Inventor Katsuhiko Nishino 1-2-1, Marunouchi, Chiyoda-ku, Tokyo Sun (72) Inventor Masahiro Ikeda 5-5-1 Shirokane, Minato-ku, Tokyo Keiwa Kogyo Co., Ltd.

Claims (5)

[Claims] 1. A tubular joint body having a concentrically projecting connection port to which a pipe is externally fitted, an elastically expandable and contractible retaining ring, and a screw-fittable fitting on the joint body. And a push ring through which the tube is inserted, a ring portion into which the tip of the tube inserted through the push ring can be inserted, and a tip of the tube inserted into the ring portion by protruding radially inward of the ring portion. A stop ring support that has a contact portion with which the surface abuts and is supported by the inside of the stopper ring to support the stopper ring in a state where the diameter of the stopper ring is expanded against its elasticity. The joint body is provided with a projection concentrically protruding around the connection port, and the retaining ring support and the retaining ring support are provided between the projection and the connection port. A tube end insertion space into which the tip of the tube inserted into the loop is inserted is formed, A receiving surface against which one end of the retaining ring abuts is formed on an end surface of the protruding portion, and the pressing ring is provided with a pressing surface for pressing the other end of the retaining ring. And the pressing surface are formed in a tapered shape whose diameter gradually increases as they approach each other in a state where the pressing ring is screwed into the joint body, and the receiving surface of the projecting portion and the pressing surface of the pressing ring On the inner peripheral side of the retaining ring disposed between the retaining ring and the retaining ring support body, which is fitted inside the retaining ring, is pushed out of the retaining ring by the pipe and the retaining ring is Is compressed by the initial biting teeth which are hooked on the outer periphery of the pipe when the diameter of the pipe is reduced by its own elasticity, and the receiving surface of the projecting portion and the pressing surface of the pressing ring screwed to the joint body. Slides between the receiving surface and the pressing surface. Pipe fitting, characterized in that the 突歯 to bite the outer periphery of the tube is provided when said retainer ring is reduced in diameter while. 2. The retaining ring has an initial biting tooth on the inner circumference on the other end side, has the protruding teeth on an inner circumference on one end side of the initial biting tooth, and has the press ring. The diameter of the other end of the retaining ring pressed by the pressing surface is larger than the diameter of one end of the retaining ring abutting on the receiving surface of the protrusion, and the diameter of the retaining ring is 2. The pipe joint according to claim 1, wherein a pressing portion for pressing the other end portion without sliding is provided at an end portion on the small diameter side of the pressing surface. 3. 3. A small diameter end of the receiving surface and an end of an outer peripheral surface of the tube end insertion space are connected to each other, and a margin for screwing the pressing ring into the joint body is reduced by the pressing portion. 3. The pipe joint according to claim 2, having a length capable of pushing one end of the retaining ring into the pipe end insertion space. 4. The pipe joint according to claim 1, wherein an opening angle of the receiving surface and an opening angle of the pressing surface are set to be the same. 5. The pipe according to claim 1, wherein the outer peripheral side of the connection port is provided with a protruding tooth which can bite into the inner circumference of the pipe. Pipe fittings.