JP2013221586A - Pipe joint - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pipe joint capable of exhibiting reliable pipe pull-out force with less pressure loss.SOLUTION: A seal groove of a pipe joint including a joint body 4 having a pipe inserting inner cylinder part 1 and a surrounding cylinder part 3 surrounding the inner cylinder part 1 from the outer peripheral side to form an outward open cylindrical space part 2 is eliminated to provide a seal 14 abutting on the outer peripheral surface of an inserted pipe P. An inner part of the pipe joint is provided with an inner part temporary slip-off preventing mechanism K, and a proper slip-off preventing mechanism Z is provided near an opening.

Description

  The present invention relates to a pipe joint.

The inventor has conventionally proposed many pipe joints. For example, a patent application has been filed for a pipe joint having a structure as shown in FIG. 15 (see Patent Document 1).
That is, the pipe joint shown in FIG. 15 includes a joint body 32 having an insertion cylinder portion 33 inserted into the end of the pipe 31 to be connected, and a seal attached to the concave circumferential groove 37 of the insertion cylinder portion 33. A member 34, a tightening ring 35 with a slit 51 for tightening the end of the pipe 31 fitted on the insertion tube portion 33 with a resilient tightening force, A diameter-expanded portion that is removably held at the end of the slit 51 so as to expand the diameter of the fastening ring 35 against a resilient force, and comes into contact with the tip of the pipe 31 to be inserted. Proposed a pipe joint having a structure including a piece 36 and a retaining ring 38 that the inner peripheral side is latched to the outer peripheral surface of the pipe 31 that is externally fitted to the insertion cylinder 33 in a retaining state. It has gained popularity in plumbing work.

Japanese Patent No. 3411546

The conventional pipe joint as illustrated in FIG. 15 described above has an extremely stable and strong strength by the tightening ring 35 that is tightened with a strong elastic force and the retaining ring 38 (having a large number of teeth 42). In addition, the pipe pulling force can be exhibited, and the sealing member 34 provided in the insertion tube portion 33 has an advantage that stable sealing performance can be exhibited.
However, since the inner diameter dimension d of the flow path hole 39 of the insertion cylinder part 33 needs to be provided with the concave circumferential groove 37 on the outer peripheral surface of the insertion cylinder part 33, it must be set very small. For example, compared to the inner diameter dimension D of the pipe 31, the inner diameter dimension d of the flow path hole 39 is about 60% to 65%, and therefore, about 40% of the flow path cross-sectional area of the pipe 31 and the flow path hole. There was a problem that the cross-sectional area of 39 was small. Along with this, there has been a problem that the passage resistance of fluid (water, hot water, etc.) flowing through the piping becomes excessive.

  Conventionally, there has been proposed a structure in which the concave cylindrical groove 37 is omitted in the insertion tube portion 33 and an O-ring is provided so as to be pressed against the outer peripheral surface 31A of the pipe 31. However, however, the pipe 31 is used as a pipe joint. At the time of insertion, a large number of streaks (scratches) are generated on the outer peripheral surface 31A by the teeth 42 of the retaining ring 38 shown in FIG. 15, and external fluid leakage occurs between the outer peripheral surface 31A and the O-ring. May occur.

  Accordingly, the present invention provides a pipe joint that solves such a conventional problem and reduces the fluid passage resistance (pressure loss) by omitting a sealing material (seal circumferential groove for sealing) from the insertion tube portion. The second object is to provide a pipe joint that prevents the occurrence of scratches at the time of insertion of the pipe to be connected, has a stable sealing performance, and has a high pressure. A third feature is to provide a pipe joint that exhibits a strong pull-out resistance during operation and can reliably prevent pipe pull-out due to the accumulation of pull-outs of extremely small dimensions due to pipe vibration and small external forces. Objective.

  Accordingly, the present invention provides a joint body having an inner cylinder part for pipe insertion in which a seal groove is omitted, and an enclosing cylinder part that surrounds the inner cylinder part from the outer peripheral side to form an outwardly open cylindrical space part. A pipe joint provided with a section; a temporary provisional retaining mechanism at the back, which is fixed at the distal end of the outer peripheral surface of the pipe to be connected that is disposed at the back of the space and inserted into the space. And a permanent retaining mechanism disposed in the vicinity of the opening of the space to strongly retain the pipe; and a space between the temporary retaining mechanism and the permanent retaining mechanism so as to be interposed between the temporary retaining mechanism and the permanent retaining mechanism. An annular piston having an inner peripheral seal and an outer peripheral seal disposed at an intermediate portion; and when the annular piston receives fluid pressure and / or When receiving the movement in the drawing direction, the main holding mechanism is configured to operate.

Further, the main retaining mechanism is configured such that the tapered inner peripheral surface formed on the surrounding cylinder portion is reduced in diameter toward the tip opening side, and is not in contact with the outer peripheral surface of the pipe when the pipe is inserted, And a retaining ring with a biting claw that shrinks in diameter while sliding on the tapered inner peripheral surface as the annular piston moves in the pulling direction.
In addition, the annular plate portion having an axial center orthogonal shape, and an inclined plate portion that is bent radially inward from the inner peripheral edge of the annular plate portion and in the back direction, and an inserted pipe With the locking ring body formed on the inner peripheral edge of the inclined plate part, the inner part of the inner part is always in contact with the tip of the outer peripheral surface and bites as the pipe moves in the pulling direction. Configured.
Further, a tightening ring formed of a C-type elastic member with a slit and a removably inserted into the slit so as to expand the diameter of the tightening ring against the elastic force of the tightening ring. The above-mentioned inner temporary removal preventing mechanism is configured with an enlarged diameter tip that comes into contact with and separates from the tip of the inserted pipe.

ADVANTAGE OF THE INVENTION According to this invention, the pressure loss of the fluid which passes a pipe joint (flow path hole) can be reduced. In addition, the annular piston can maintain good sealing performance on the outer surface of the pipe, especially when the pipe is inserted, scratches on the outer surface of the pipe are only in the inner part of the pipe joint--only in the most advanced area of the pipe ――― Generates and keeps the pipe outer peripheral surface smooth at the piston sealing position, and exhibits excellent sealing performance.
Furthermore, even if a small pulling external force or vibration is applied to the pipe, the back temporary pull-out preventing mechanism works effectively, and pulling-out associated with pull-out accumulation of extremely small dimensions can be prevented. In addition, when a large pulling force is applied (that is, when a mechanical pulling external force or a pulling force by receiving a high fluid pressure is applied), the pull-out preventing mechanism is operated via a piston to provide strong pulling resistance. I can demonstrate my power.

It is sectional drawing of the state before insertion of the pipe which shows one Embodiment of this invention. It is sectional drawing of the state which inserted the pipe. It is explanatory drawing which shows the state which the inner part temporary removal prevention mechanism act | operated. It is explanatory drawing which shows the state which this book keeping mechanism act | operated. It is the perspective view which showed an example of the latching ring body. It is the perspective view which showed one example of the retaining ring used for this retaining mechanism. It is the perspective view which showed the other example of the retaining ring used for this retaining mechanism. It is sectional drawing of the state before the pipe insertion which shows other embodiment of this invention. It is a figure which shows an example of the fastening ring body which consists of an elastic wire, Comprising: (A) is a front view which shows a diameter-expanded state, (B) is a front view which shows a diameter-reduced state, (C) is a figure of (B). It is CC sectional drawing in a front view. It is a figure which shows an example of a diameter expansion chip | tip, Comprising: (A) is a front view, (B) is a left view, (C) is a right view, (D) is a top view. It is a front view which shows the unit state in which the diameter-expansion chip | tip was clamped. It is sectional drawing which showed the state immediately after inserting a pipe. It is explanatory drawing which shows the state which the inner part temporary removal prevention mechanism act | operated. It is explanatory drawing which shows the state which this book keeping mechanism act | operated. It is sectional drawing which showed the prior art example.

Hereinafter, the present invention will be described in detail based on the illustrated embodiment.
In the embodiment of the present invention shown in FIGS. 1 to 7, P is a pipe to be connected, and the material is cross-linked polyethylene (cross-linked PE), polybutene, Cu pipe, Al pipe, etc. In the pipe joint 10 according to the invention, the seal groove is omitted--the conventional concave circumferential groove 37 shown in FIG. 15 is omitted --- the pipe-inserting inner cylindrical portion 1 and the inner cylindrical portion 1 on the outer peripheral side. A joint body portion 4 having an enclosing cylinder portion 3 that surrounds the outer space and forms an outwardly open cylindrical space portion 2.

The joint body portion 4 has a passage hole 5 penetrating along the axis L _4. A screw cylinder portion 7 having a male screw 6, an intermediate cylinder portion 8, a large-diameter cylinder portion 9 that forms the back and middle portions of the space portion 2, and the pipe insertion inner cylinder portion 1 are made of plastic or metal. Are fixed to the tip of the integrally formed body portion 11 and the large-diameter cylindrical portion 9 of the body portion 11 by heat fusion, mechanical forced fitting, adhesion, or the like, and the open end of the space portion 2 And an outer cylindrical body 12 forming a portion.
In other words, in the present invention, the joint main body 4 includes the body 11 and the outer cylinder 12. Further, the surrounding cylinder part 3 includes a large diameter cylinder part 9 and an outer cylinder 12.

And in the back part of the outer opening cylindrical space part 2 formed by the surrounding cylinder part 3 and the inner cylinder part 1, as shown in FIG. 2 and FIG. A back portion temporary removal preventing mechanism K is provided that is fixed to the outer peripheral surface tip 13 of the pipe P that has been inserted in the direction of the arrow E into the portion and prevents the removal.
Further, near the opening of the space portion 2, there is provided a full retaining mechanism Z that strongly retains the pipe P (performs a full retaining action).
Here, “strongly retaining” is defined to mean retaining with a retaining force that is more than twice that of the inner temporary retaining mechanism K. .

In addition, an annular piston 15 disposed at an intermediate portion (in the direction of the axis L ₄ ) of the cylindrical space portion 2 so as to be interposed between the rear temporary retaining mechanism K and the final retaining mechanism Z, It has. The piston 15 includes an inner peripheral seal 14 made of an O-ring and an outer peripheral seal 16 made of an O-ring.
In the illustrated example, the piston main body 15A of the piston 15 has a first seal groove 21 having a shape in which the inner diameter corner of the inner portion of the piston 15 is cut into a rectangular cross section, and has a flat washer shape that closes the first seal groove 21 from the inner portion. The annular flat plate 17 forms a seal groove that opens radially inward. Via the flat washer-shaped annular flat plate 17, the piston body 15 </ b> A faces the locking ring body 29 of the back temporary retaining mechanism K described later and receives the force from the locking ring body 29. It is possible. The inner peripheral seal 14 in the first seal groove 21 is brought into close pressure contact with the outer peripheral surface of the inserted pipe P to perform a sealing action.

The piston body 15 </ b> A has a second seal groove 22 in which the outer peripheral surface of the piston body 15 </ b> A is cut into a rectangular cross section, and the outer peripheral seal 16 in the second seal groove 22 is formed on the inner peripheral surface 9 </ b> A of the large-diameter cylindrical portion 9. Closely presses and seals.
Further, the piston main body 15A has a cylindrical protrusion 19 protruding in the opening direction as a shape in which the opening-side end outer peripheral corner portion is cut out.

  1-7, the retaining mechanism Z includes a tapered inner peripheral surface 20 that is formed on the outer cylinder 12 of the surrounding cylinder portion 3 and that is reduced in diameter toward the distal end opening side, and the insertion of the pipe P. In this case, as shown in FIGS. 1 and 2, the pipe is not in contact with the outer peripheral surface of the pipe, and the annular piston 15 is moved in the extraction direction X (shown in FIG. 3 or FIG. 4). And a retaining ring 23 with a biting claw 24 that reduces the diameter while being in sliding contact with the tapered inner peripheral surface 20.

The retaining ring 23 shown in FIG. 6 is a C-shaped annular ring having two biting claws 24, 24 on the inner peripheral surface and a cut portion 25 at one place on the circumference. 1 to 4, the outer surface has a tapered surface 26 that is reduced in diameter toward the opening side, and is pressed against the tapered inner peripheral surface 20 so as to be slidable. However, it bites into the outer peripheral surface of the pipe P and prevents the pipe P from being pulled out.
Further, the shape of the retaining ring 23 shown in FIG. 7 is also free, and in the example of FIG. 7, the cut portions 25 of FIG. 16 are omitted, and instead the slits are alternately arranged in the axial direction. The portion 27 is notched, and thus has a shape that is given elasticity that allows the diameter to be reduced or increased.

Next, based on FIG. 1 to FIG. 5, the back temporary retaining mechanism K will be described, and it has a locking ring body 29 having a large number of locking claws 28 (as shown in FIG. 5). . More specifically, an annular plate portion 30 orthogonal to the axis L ₄ , and an inclined plate portion 40 that is bent radially inward from the inner peripheral edge of the annular plate portion 30 in the back direction, and 2 (as shown in FIGS. 2 to 4), and a plurality of locking claws 28 that always contact the outer peripheral surface tip 13 of the inserted pipe P and bite in as the pipe P moves in the drawing direction X. Is formed at the inner peripheral edge of the inclined plate portion 40 to constitute the rear temporary removal preventing mechanism K.

Next, another embodiment shown in FIGS. 8 to 14 will be described. Explaining from the configuration different from the embodiment described in FIG. 1 to FIG. 7, the inner part temporary retaining mechanism K includes a tightening ring 43 formed of a C-type elastic member with a slit (cut part) 41. The fastening ring 43 can be detached from the slit 41 so as to expand the diameter of the fastening ring 43 (as shown in FIGS. 9B to 9A) against the elastic force of the diameter reduction direction of the fastening ring 43. The deep-part temporary removal preventing mechanism K is configured with the enlarged-diameter tip 44 that is inserted and held (as shown in FIG. 11).
As shown in FIG. 8 to FIG. 12, when the diameter-expanded tip 44 is detached from the slit (cut portion) 41 toward the back side by contacting the tip end portion of the pipe P inserted from the direction of arrow E, FIG. 9 (A)), as shown in FIG. 9 (B), as shown in FIGS. 12, 13, and 14, the tightening ring 43 is formed on the outer peripheral surface tip 13 of the pipe P as shown in FIG. It is strongly tightened by the elastic urging force and integrated with the pipe P.

In addition, in the embodiment shown in FIGS. 8 to 14, the fastening ring 43 is made of a wire material such as spring steel having a circular cross section, and has a substantially triangular small notch along the inner peripheral edge (as shown in FIG. 9). By forming 45, a locking claw portion 46 is formed to press against the outer peripheral surface of the pipe P with a strong surface pressure or to bite (see FIGS. 12 and 13). Further, the small diameter notches 47 and 47 for holding the enlarged diameter tip 44 illustrated in FIG. 10 in a stable posture and position in the slit 41 are provided at the inner peripheral end corner of the end face of the wire forming the slit 41. Forming.
Other configurations described above in FIGS. 8 to 14 are mainly the same as those in FIGS. 1 to 7, and the same reference numerals indicate the same configurations. In particular, the piston 15 and the main retaining mechanism Z are the same as those shown in FIGS.

Next, in both the embodiments of FIGS. 1 to 7 and FIGS. 8 to 14, the additional description of the configuration and the operation will be described. When the fluid pressure p is received as shown in FIG. 4, the cylindrical space portion 2 moves outward (along the axis L ₄ ) so that the cylindrical protrusion 19 is retained by the retaining ring 23 as indicated by the arrow F. The inner end face is strongly pressed, and the full retaining mechanism Z is operated. That is, as shown by the arrow G, the biting claw 24 is bitten into the outer peripheral surface of the pipe P while the diameter of the retaining ring 23 of the retaining mechanism Z is reduced, and the retaining ring 23 is strongly retained. At that time, due to the sliding pressure contact between the tapered surface 26 and the tapered inner peripheral surface 20 (so-called wedge action), a strong radial reduction force indicated by an arrow G in the radial direction acts on the biting claw 24.

Further, when the fluid pressure p is completely zero, or, if a case is described a low pressure value, outward annular piston 15 along the retainer ring 23 of the retaining mechanism Z (the axis L ₄ F) The pressing force is zero or very small. For this reason, if it is assumed that there is no back temporary removal preventing mechanism K, the pipe P is pulled out with a small pulling force. In particular, the biting claw 24 of the retaining ring 23 is in a non-contact or extremely light contact state with the outer peripheral surface of the pipe P in the state of FIGS. Will be pulled out. Furthermore, there are cases where the pipe is pulled out at one time and pipes are pulled out after a long period of use due to accumulation of minute strokes.

However, in the present invention, the fluid pressure p is provided by providing the inner portion temporary removal preventing mechanism K that is fixed to the outer peripheral surface tip 13 of the pipe P inserted into the inner portion of the space portion 2 to prevent it from being removed. Pipe pull-out in the case of zero or low pressure can be reliably prevented.
The operation will be described. In FIG. 1, the pipe P is inserted into the pipe joint 10 in the direction of the arrow E, and the engagement of the rear temporary retaining mechanism K provided in the inner part of the cylindrical space 2 is illustrated. The locking claw 28 of the stop ring body 29 is elastically pressed against the outer peripheral surface tip 13 to be in the state shown in FIG. 2, and thereafter, even if the pipe P attempts to move in the pulling direction X with a small pulling force, It can be blocked by the pawl 28. Moreover, when a larger pulling force is applied to the pipe P (mechanically), the locking claw 28 of the locking ring body 29 stands up as shown by the arrow H as shown in FIG. And the movement P in the pulling direction of the pipe P is transmitted to the piston 15 to press the retaining ring 23 as indicated by arrows J and N. Accordingly, the retaining ring 23 is tapered. The surface 26 is reduced in diameter while being in sliding contact with the tapered inner peripheral surface 20, and the biting claw 24 is bitten into the outer peripheral surface of the pipe P as shown by an arrow G ′, so that pulling out can be reliably prevented.

In this way, even when receiving the movement X in the withdrawal direction of the back temporary retaining mechanism K, the retaining mechanism Z can be operated to prevent (mechanical) withdrawal.
Of course, when the (mechanical) pulling force described with reference to FIG. 3 is applied at the same time when the fluid pressure p of FIG. 4 is received, the retaining mechanism Z has a tapered surface 26 and a tapered shape. Due to the sliding contact of the inner peripheral surface 20 (by wedge action), a stronger radial shrinking force in the direction of the arrows G and G 'acts on the claw 24 and can more firmly prevent the pipe from being pulled out. is there.

  Next, the operation of the other embodiments shown in FIGS. 8 to 14 will be described. In FIG. 8, when the pipe P is inserted into the pipe joint 10 in the direction of arrow E, the cylindrical space As shown in FIG. 12, the pipe tip collides (contacts) with the diameter-enlarged tip 44 of the back temporary retaining mechanism K provided at the back of 2 and is detached from the tightening ring 43 as shown in FIG. At this time, since a clicking sound can be heard, the operator can confirm that the pipe P has been inserted deeply. By this disengagement, the tightening ring 43 of FIG. 12 is elastically pressed against the pipe outer peripheral surface tip 13 (or the engaging claw portion 46 bites in) and becomes the state of FIG. 12, and thereafter, as shown in FIG. As described above, even if the pipe P attempts to move in the pulling direction X with a small pulling force, the tightening ring 43 can prevent the pipe P from moving. Moreover, when a larger pulling force is applied to the pipe P (mechanically), the fastening ring 43 strongly tightens the outer peripheral surface of the pipe by its own elastic urging force (as shown in FIG. 13). Is transmitted to the piston 15 (via the annular flat plate 17), and the retaining ring 23 is pressed as indicated by the arrow N. Accordingly, the retaining ring 23 is retained. The ring 23 is reduced in diameter while the taper surface 26 is in sliding contact with the taper inner peripheral surface 20, and the biting claw 24 is bitten into the outer peripheral surface of the pipe P as shown by an arrow G ′ to pull out the ring 23. Can be surely stopped.

In this way, even when receiving the movement X in the withdrawal direction of the back temporary retaining mechanism K, the retaining mechanism Z can be operated to prevent (mechanical) withdrawal.
Of course, when the (mechanical) pulling force described in FIG. 13 is applied at the same time when the fluid pressure p shown in FIG. 14 is received, the retaining mechanism Z has a tapered surface 26 and a tapered shape. By sliding contact of the inner peripheral surface 20 (due to the wedge action), a stronger total diameter reducing force in the radial inward direction in the directions of arrows G and G ′ acts on the claw 24 and can further prevent the pipe from being pulled out. It is.

The present invention is not limited to the illustrated embodiment described above, and the design can be changed without changing the gist thereof, and the annular flat plate (washer) 17 may be omitted. One seal groove 21 can be freely formed as a concave groove that opens only in the radial inward direction. That is, the annular flat plate 17 may be omitted, and the first seal groove 21 may be provided in the piston 15 so as to be open in the radial inward direction. The seals 14 and 16 may be square rings, U-packings, or the like as seals other than O-rings, or may be baked or integrally molded on the piston 15. Further, the cross-sectional shape of the retaining ring 23 of the retaining mechanism Z is freely deformable, and even if the number of biting claws 24 is increased or decreased, or the thin-walled shape that is elastically deformed is used partially or entirely. good.
The inner diameter d of the inner cylinder portion 1 of the present invention can be about 77% to 90% of the inner diameter D of the connected pipe P. That is, the cross-sectional area of the flow path hole 5 is large as about 60% to 80% of the cross-sectional area of the flow path of the pipe 1, and the passage resistance (pressure loss) of the fluid can be significantly reduced.

  As described above, the present invention includes a pipe insertion inner cylinder portion 1 in which a seal groove is omitted, and an enclosure that surrounds the inner cylinder portion 1 from the outer peripheral side to form an outwardly open cylindrical space portion 2. It is a pipe joint provided with a joint body part 4 having a cylindrical part 3; it is disposed on the outer peripheral surface tip 13 of the connected pipe P which is disposed in the back part of the space part 2 and inserted into the back part. A rear temporary retaining mechanism K that is worn and secured; a permanent retaining mechanism Z that is disposed in the vicinity of the opening of the space portion 2 and that strongly retains the pipe P; and the temporary retaining mechanism K An annular piston 15 having an inner peripheral seal 14 and an outer peripheral seal 16 disposed in an intermediate portion of the space 2 so as to be interposed between the main retaining mechanism Z; When the annular piston 15 receives the fluid pressure p and / or receives the movement X in the withdrawal direction of the back temporary retaining mechanism K, the permanent retaining is performed. Therefore, the seal can be omitted from the pipe insertion inner cylinder portion 1, the cross-sectional area of the flow path hole 5 can be remarkably increased, and the pressure loss can be reduced. In addition, the provision of a back-prevention mechanism K at the back of the pipe joint prevents scratches on the outer peripheral surface of the pipe P, and the sealing performance (sealing performance) by the inner peripheral seal 14 of the piston 15 is stable. And become good. Moreover, the back temporary pull-out preventing mechanism K can prevent the pull-out of the pipe accompanying the accumulation of a very small pull-out during long-term use due to the vibration of the pipe P and the small pull-out force. In addition, when the fluid pressure is high or when a strong pipe pull-out force is applied mechanically, the strong pull-out force by the pull-out prevention mechanism Z can be exerted, and the pipe pull-out accident can be reliably prevented. .

1 Pipe insertion inner cylinder part 2 Cylindrical space part 3 Surrounding cylinder part 4 Joint body
12 outer cylinder
13 Outer peripheral surface tip
14 Inner circumference seal
15 piston
16 Outer seal
20 Tapered inner peripheral surface
23 Retaining ring
24 biting nails
28 Locking claw
29 Locking ring body
30 Ring plate
40 Inclined plate
41 Slit (cut part)
43 Clamp ring
44 Expanded tip P Connected pipe p Fluid pressure X Movement in the pulling direction K Back temporary retaining mechanism Z Regular retaining mechanism

Claims (4)

The pipe-inserting inner cylinder part (1) in which the seal groove is omitted, and the enclosing cylinder part (3) that surrounds the inner cylinder part (1) from the outer peripheral side to form the outer open cylindrical space part (2) A pipe joint provided with a joint body (4) having
A rear temporary retaining mechanism (not shown) that is attached to the outer peripheral surface tip (13) of the connected pipe (P) that is disposed in the inner part of the space (2) and is inserted into the inner space. K) and
A main retaining mechanism (Z) disposed in the vicinity of the opening of the space portion (2) to firmly retain the pipe (P);
An inner peripheral seal (14) and an outer peripheral seal (14) disposed in an intermediate portion of the space (2) so as to be interposed between the temporary retaining mechanism (K) and the permanent retaining mechanism (Z). An annular piston (15) provided with 16),
When the annular piston (15) receives the fluid pressure (p) and / or receives the movement (X) in the pulling direction of the back temporary retaining mechanism (K), the retaining mechanism ( A pipe joint characterized in that Z) is operated.   The main retaining mechanism (Z) includes a tapered inner peripheral surface (20) formed in the surrounding cylinder portion (3) and having a diameter reduced toward the distal end opening, and a pipe outer periphery when the pipe (P) is inserted. Biting claws (24) that are non-contact with the surface and that reduce the diameter while slidingly contacting the tapered inner peripheral surface (20) as the annular piston (15) moves in the pulling direction (X) The pipe joint according to claim 1, comprising a retaining ring with a flange.   An axially orthogonal annular plate portion (30), and an inclined plate portion (40) bent radially inward from the inner peripheral edge of the annular plate portion (30). In addition, the inclined plate portion is provided with a large number of locking claws (28) that are always in contact with the distal end (13) of the outer peripheral surface of the inserted pipe (P) and bite along with the movement (X) of the pipe (P) in the drawing direction. The pipe joint according to claim 1 or 2, wherein the inner part of the inner portion (40) is formed with the retaining ring body (29), and the inner temporary retaining mechanism (K) is configured.   A tightening ring (43) made of a C-type elastic member with a slit (41) and the diameter of the tightening ring (43) is increased against the elastic force of the tightening ring (43). And the above-mentioned inner portion of the inner portion of the inner portion of the inner portion of the inner portion of the inner portion of the inner portion of the inner portion of the inner portion. The pipe joint according to claim 1 or 2, comprising (K).

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