JP6890441B2 - Pipe fitting - Google Patents

Description

The present invention relates to pipe fittings.

For example, in water supply equipment and the like, a resin piping system for piping using a resin pipe is known, and as one of the mechanical joints for resin piping constituting this resin piping system, a nut is tightened. There is a joint.
The nut tightening joint includes, for example, an annular collet (for example, a split ring or C) in which the pipe is inserted and arranged inside the nut by tightening a nut screwed onto the outer peripheral surface of the joint body to which the pipe is mounted. A structure is adopted in which the diameter of the ring, etc.) is reduced, the pipe into which the core material of the joint body is inserted is tightened, and the pipe is held by the joint body. When the nut is tightened, the inner peripheral surface of the tapered nut moves while being in contact with the outer peripheral surface of the tapered collet, so that the collet is reduced in diameter.

In such a nut tightening joint, when the collet is incorporated into the joint body, the collet is bounded at the center in the collet axial direction in order to prevent a mistake in the collet reverse assembly that reverses the taper direction. In many cases, both sides are formed in an axially symmetric shape that is tapered with the same shape (axisymmetric shape).
Patent Document 1 is, for example, a case in which the outer peripheral surface of the collet is formed in an axially symmetric shape having the same shape on both sides with the center in the collet axial direction as a boundary.

Japanese Unexamined Patent Publication No. 2011-106538

By the way, many work sites for piping water supply equipment, etc. are narrow or difficult to take a working posture, and it takes time to tighten nuts. Therefore, labor and time are required for pipe connection work. Was often spent. In particular, if the outer peripheral surface of the collet is formed in a symmetrical shape in which both sides are tapered with the same shape on both sides of the center in the collet axial direction and both sides in the collet axial direction are symmetrical, the collet shrinks due to tightening of the nut. Since the diameter is adjusted along with the movement along the tapered surfaces on both sides of the outer peripheral surface, the stroke and the number of rotations for tightening the nut have to be increased.

For this reason, the nut is tightened to reduce the diameter of the collet whose outer peripheral surface is tapered on both sides with the same shape on both sides of the center in the collet axial direction and which is symmetrical on both sides in the collet axial direction. It has been desired to make the work quick and easy even in places where it is difficult to work.
Therefore, an object of the present invention is to provide a nut-tightened type pipe joint capable of preventing construction mistakes in reverse collet assembly and reducing labor and time for pipe connection work.

In order to achieve the above object, in the pipe joint according to the present invention, by tightening a nut screwed on the outer peripheral surface of the joint body, the pipe is inserted and the annular collet arranged inside the nut is reduced in diameter. In the pipe joint that tightens the pipe and holds the pipe, the collet is a collet whose diameter is reduced on both sides in the axial direction when the collet is tightened, and one side of the collet in the collet axial direction when the nut is tightened. It is characterized in that a diameter reduction blocking portion is provided to prevent the diameter reduction operation of the. According to the pipe joint according to the present invention, it is possible to prevent a construction error of collet reverse assembly and reduce labor and time for pipe connection work.
In the pipe joint of the present invention, it is preferable that the collet is formed in a symmetrical shape in which both sides in the collet axial direction are symmetrical with the center in the collet axial direction as a boundary. This configuration facilitates the production of collets.

In the pipe joint of the present invention, it is preferable that the diameter reduction blocking portion is a locking portion formed on the joint body or the nut to lock the collet. According to this configuration, it is possible to prevent the diameter reduction operation of one of both sides in the collet axial direction with a simple configuration.
In the pipe joint of the present invention, the joint body includes a core material into which the pipe is inserted on the outer peripheral side.
It is preferable that a recess is provided on the outer peripheral surface of the core material at a position corresponding to a position where the collet is crimped to the pipe when the diameter of the collet is reduced. According to this configuration, the pipe can be securely sandwiched and fixed.
In the pipe joint of the present invention, it is preferable that the portion where the collet presses against the pipe when the diameter of the collet is reduced has a sharp tip. According to this configuration, the pipe can be securely fixed.

According to the present invention, it is possible to provide a nut-tightened type pipe joint capable of preventing a construction error of collet reverse assembly and reducing labor and time for pipe connection work.

It is an exploded block diagram which shows each component part of the pipe joint which concerns on one Embodiment of this invention. The state in which the pipe is attached to the pipe joint of FIG. 1 is shown by a cross section of the surface including the axis of the pipe, (a) is a cross-sectional explanatory view before collet diameter reduction, and (b) is a cross-sectional explanatory view after collet diameter reduction. (C) is an enlarged cross-sectional explanatory view of the portion surrounded by the alternate long and short dash line in (a). Another example of the diameter-reduced blocking portion provided in the pipe joint of FIG. 1 is shown by a cross section of the surface including the axis of the pipe, (a) is a cross-sectional explanatory view of another example 1 of the diameter-reducing blocking portion, (b). Is a cross-sectional explanatory view of another example 2 of the diameter-reducing blocking portion, and (c) is a cross-sectional explanatory view of another example 3 of the diameter-reducing blocking portion.

Hereinafter, a mode for carrying out the present invention will be described with reference to the drawings.
As shown in FIGS. 1 and 2, the pipe joint 10 of the present embodiment has a joint body 11, a collet 12, and a nut 13, and the pipe (pipe) P can be connected in a communicating state.
In the present embodiment, the pipe joint 10 is an annular collet 12 into which the pipe P is inserted and arranged inside the nut 13 by tightening a nut 13 screwed to the outer peripheral surface of the joint body 11 to which the pipe P is mounted. Shrinks the diameter, tightens the pipe P, and holds the pipe P in the joint body 11.
The pipe joint 10 of the present embodiment is, for example, a nut tightening which is one of the mechanical joints for resin piping that constitutes a resin piping system for performing piping using a resin pipe P in a water supply facility or the like. Functions as a joint.

In the present embodiment, the joint body 11, the collet 12 and the nut 13 constituting the pipe joint 10 are made of metal, but a part or all of the joint body 11, the collet 12 and the nut 13 may be made of resin or the like. It may be formed of a member other than metal. In that case, it is preferable that the joint body 11 and the nut 13 are made of metal and the collet 12 is made of resin.
In the present embodiment, the joint body 11 is formed in a substantially cylindrical shape, the core material 14 is projected toward the opening on one end side (right side in FIG. 1), and the outer peripheral surface is, for example, the head of a hexagon nut. A rotating action portion 11a and a male screw portion 11b having a shape are formed (see FIG. 1). In the present embodiment, the core material 14 is provided with a water-stopping O-ring 15 for inserting a pipe P on the outer peripheral side and stopping water between the inserted pipe P and rotating the core material 14. A tool such as a spanner can be locked to the operation portion 11a to apply rotational power, and a nut 13 can be screwed to the male screw portion 11b (FIGS. 2A, 2). b) See).

It is not necessary to provide the core material 14 on the joint body 11. In this case, for example, an O-ring is attached to the outer peripheral surface of the pipe P to be inserted into the internal space of the male screw portion 11b, and the male screw portion 11b is provided. It is in close contact with the inner peripheral surface to stop water on the outer surface.
In the present embodiment, the pipe socket 16 communicating with the opening protrudes integrally with the joint body 11 in the opening of the joint body 11 on the side opposite to the side where the core material 14 is projected (left side in FIG. 1). It is installed (see Fig. 1). By attaching another pipe (not shown) to the pipe socket 16, the core material 14 and the pipe P attached to the pipe socket 16 and other pipes can communicate with each other via the pipe joint 10.

In the present embodiment, the collet 12 is a collet whose diameter is reduced on both sides in the axial direction when tightened, and exhibits an annular shape provided with a plurality of notches 17, and the outer peripheral surface is defined by the center in the collet axial direction as a boundary. It is formed in a symmetrical shape in which both sides in the collet axial direction are symmetrical, and as an example, a symmetrical shape in which both sides have the same shape and a tapered shape with a dented tip with the center in the collet axial direction as a boundary. Here, the symmetrical shape includes a shape that is substantially symmetrical. Here, substantially symmetric means that, in the present embodiment, there is a notch 17 which is arranged by alternately reversing the cutting direction in the collet axial direction, which will be described later, or when the collet is circumferential like a C ring. It means that the skeleton structure should have symmetry, including the case where a part is missing in the direction. In the present embodiment, the shape of the tapered tip is a central portion 12a formed of a plane substantially parallel to the collet axis at the center in the collet axial direction, and a downward slope from the central portion 12a toward the openings on both sides in the collet axial direction. It has a tapered portion 12b that is on the rotating action portion 11a side when mounted on the joint body 11, and a tapered portion 12c that is on the protruding end side of the core material 14 (FIGS. 1 and 2). (A), (b)).

The taper angle of the tapered portion 12b and the tapered portion 12c of the collet 12 with respect to the collet axial direction is preferably 10 ° to 35 °, more preferably 15 ° to 25 ° in the present embodiment. When the taper angle is 15 ° to 25 °, the tightening torque when tightening the nut can be reduced, and when the taper angle is 20 ° to 25 °, the tightening stroke when tightening the nut can be shortened. it can. The tightening torque is lower when the taper angle is closer to the 10 ° side, and the tightening stroke can be reduced when the taper angle is closer to the 35 ° side. However, if the taper angle is made too close to 10 °, a force is applied so that the collet that bites into the pipe pushes the pipe toward the back side of the joint when tightening, so that the tightening torque reducing effect is conversely reduced.

Since the collet 12 is provided with a plurality of notches 17, a discontinuous portion is formed in the circumferential direction of the collet 12, and the diameter can be reduced so as to narrow down by pressing the outer peripheral surface (FIG. FIG. 1). The notches 17 of the present embodiment are arranged at a plurality of positions in the circumferential direction of the collet 12 at predetermined circumferential intervals (constant intervals in this example), and the cut directions are alternately reversed in the collet axial direction (FIG. 6). (See 1), for example, a split ring, a C ring, or the like, which can reduce the diameter so as to narrow down by forming a discontinuous portion in the circumferential direction and pressing the outer peripheral surface, may be used.

Further, in the present embodiment, the collet 12 has the inner peripheral surface of the nut 13 screwed to the male screw portion 11b of the joint body 11 and the pipe P attached to the core material 14 with the core material 14 inserted. The shape and size can be arranged in the gap space d formed between the outer peripheral surface and the outer peripheral surface of the above, and can be displaced and moved in the collet radial direction and the collet axial direction in the gap space d. It has (see FIGS. 2 (a) and 2 (b)).
Further, in the collet 12, in the present embodiment, the inner peripheral surface facing the outer peripheral surface of the pipe P inserted into the collet 12 is provided with pipes at three locations, the center in the collet axial direction and both ends, over the entire circumference except for the notch 17. A ridge portion 12d protruding toward the P side is formed (see FIGS. 1, 2 (a) and (b)). It is preferable that the convex portions 12d are provided at least at two positions at both ends in the collet axial direction.

In the present embodiment, the nut 13 has a tapered tip on one end side (right side of FIGS. 1, 2 (a) and (b)) which is the protruding end side of the core material 14 when mounted on the joint body 11. It is formed in a substantially cylindrical shape, and has a female screw portion 13a that can be screwed to the male screw portion 11b of the joint body 11 on the inner peripheral surface on the other end side, and is screwed to the male screw portion 11b. With the other end side in contact with the joint body 11, the one end side end has a length in the nut axial direction at substantially the same position as the protruding end of the core member 14 (FIGS. 1 and 2 (FIGS. 1 and 2). See a) and (b)). In the present embodiment, the nut 13 in which the female screw portion 13a is screwed to the male screw portion 11b of the joint body 11 is continuously tightened from the time when the female screw portion 13a and the male screw portion 11b start to be screwed to each other. The nut tightening amount s is the distance to the point where the end end is brought into contact with the joint body 11 (see FIG. 2A).

Further, the opening at one end side (right side of FIGS. 1, 2 (a) and (b)) of the nut 13, that is, the tip opening having a tapered tip is connected to the joint body 11 of the nut 13 in the present embodiment. Is formed to have an inner diameter that allows the core material 14 to be inserted so as to be substantially in close contact with the outer peripheral surface of the pipe P mounted on the joint body 11. The tapered inner peripheral surface is formed by a tapered portion 13b formed of an inclined surface whose diameter gradually increases toward the other end side (see FIGS. 2A and 2B). When the nut 13 is attached to the joint body 11, the collet 12 arranged in the gap space d between the inner peripheral surface of the nut 13 and the outer peripheral surface of the pipe P has only one inclined surface 12c, which is a tapered portion of the nut 13. It is in a state of facing 13b (see FIGS. 2A and 2B).

On the other end side of the outer peripheral surface of the nut 13, for example, a head-shaped rotating action portion 13c of a hexagon nut, which is similar to the rotating action portion 11a of the joint body 11, is formed in the present embodiment ( (See FIGS. 1, 2 (a) and (b)).
By mounting the nut 13 on the joint body 11 (see FIG. 2A) and tightening the nut 13, the nut 13 hits the tapered portion 13b against the tapered portion 12c of the collet 12 on the protruding end side of the core material 14. When they are brought into contact with each other, the tapered portion 13b and the tapered portion 12c move while being in contact with each other (see FIG. 2B), and as the tightening progresses, the tapered portion 12c is tapered over the entire peripheral surface. It is further pushed toward the pipe P side by the portion 13b.

As the tapered portion 12c is further pushed toward the pipe P and narrowed down, the collet 12 is reduced in diameter, and as a result, each convex portion 12d of the collet 12 extends over the entire outer peripheral surface of the pipe P penetrating the collet 12. It bites into the pipe (see FIG. 2B), tightens the pipe P, and the pipe P is sandwiched and fixed between the collet 12 and the core material 14 mounted on the joint body 11 to which the nut 13 is screwed. This is the case (see FIG. 2B).

Then, as shown in FIG. 2, the pipe joint 10 of the present embodiment has a diameter reduction blocking portion that prevents the collet 12 from reducing the diameter on one side (only one side) in the collet axial direction when the nut 13 is tightened. It is provided. In the present embodiment, the diameter reduction blocking portion is an annular axial end portion of the collet 12 formed on the axial end surface of the joint body 11 facing the collet 12 (here, on the rotating action portion 11a side). An annular recess 18a (see FIG. 2C) corresponding to this end can be inserted (see FIG. 2B) and functions as a locking portion for locking the collet 12. ..

When the nut 13 mounted on the joint body 11 is tightened (that is, moved to the joint body 11 side) by the annular recess 18a provided in the joint body 11 as a diameter reduction blocking portion, the core material 14 is inserted. The collet 12 arranged inside the nut 13 in a state of penetrating the pipe P is locked by the end portion on the tapered portion 12b side (rotating action portion 11a side) entering the annular recess 18a (FIG. 2 (b)), the movement to the rotating action portion 11a side is prevented. The annular recess 18a functions as a locking portion when the end portion of the collet 12 enters and locks, and when the collet 12 is locked, one side in the collet axial direction (here, the tapered portion 12b side). It is possible to prevent the diameter reduction operation of. Therefore, as the collet 12 whose movement to the rotating action portion 11a side is prevented is tightened, only the tapered portion 12c side is pushed toward the pipe P side on the entire peripheral surface and is narrowed down. (See FIG. 2 (b)).

That is, the diameter reduction of the collet 12 due to the tightening of the nut 13 is not the taper portions 12b and 12c on both sides of the outer peripheral surface of the collet 12, but the movement of the tapered portion 13b of the nut 13 along the tapered portion 12c on only one side of the outer peripheral surface. Therefore, even if the collet 12 is formed in a symmetrical shape having the same shape on both sides with the center in the collet axial direction as a boundary, the diameter of the collet 12 is reduced by tightening the nut 13. However, the stroke and the number of rotations for tightening the nut 13 can be substantially halved as compared with the case where the nut 13 is moved along the tapered surfaces on both outer peripheral surfaces of the collet 12.

As described above, in the pipe joint 10 of the present embodiment, the outer peripheral surface of the collet 12 is tapered on both sides having the same shape with the center in the collet axial direction as a boundary, and both sides in the collet axial direction are symmetrical. Since it is formed into a shape, it is possible to prevent construction mistakes in reverse assembly of the collet, and by reducing the diameter of only the other side without reducing the diameter of one side of the taper shape (see FIG. 2B), the number of nuts 13 is reduced. The collet 12 can be reduced in diameter and tightened by the tightening amount. Therefore, labor saving in the connection work of the pipe P using the pipe joint 10 becomes possible, and even in the pipe connection work in a place where the work is difficult, the connection work can be performed quickly and easily, and the labor and time can be achieved. Can be reduced.

Next, another example of the diameter reduction prevention portion provided in the pipe joint 10 will be described.
As shown in FIG. 3A, in another example 1 of the diameter reduction blocking portion, the diameter reduction blocking portion is formed on the entire circumference of the axial end surface of the joint body 11 facing the collet 12. An annular ridge 18b corresponding to the groove-shaped recess 12e into which the groove-shaped recess 12e can enter is provided. The groove-shaped recesses 12e of the collet 12 are provided in an annular shape centered on the collet shaft over the entire circumference of the end faces on both sides in the axial direction of the collet 12 (see FIG. 3A). By entering and locking the groove-shaped recess 12e, it functions as a diameter reduction blocking portion.

In the configuration in which the annular ridge 18b as the diameter reduction blocking portion is formed on the joint body 11, the annular axial end of the collet 12 formed on the axial end surface of the joint body 11 described above. Similar to the annular recess 18a into which the portion can be inserted, the tapered portion 13b of the nut 13 and the tapered portion 12c of the collet 12 come into contact with each other and are in sliding contact with each other. The portion 12b side is fixed, and only the tapered portion 12c side of the collet 12 is pushed toward the pipe P side on the entire peripheral surface and narrowed down, so that the diameter is reduced.

Further, as shown in FIG. 3B, in another example 2 of the diameter reduction blocking portion, the diameter reduction blocking portion is not the annular recess 18a (see FIG. 2) provided in the joint body 11 described above, but the diameter reduction blocking portion. The annular recess 18c provided in the nut 13 is used. The annular recess 18c is located in the nut 13 where the tapered portion 13b (see FIG. 3A) was formed, in the axial direction of the collet 12 as in the annular recess 18a provided in the joint body 11. This end is provided so as to face the end face so that the annular axial end portion of the collet 12 (here, the protruding end side of the core member 14) can enter (see FIG. 3B). It is formed corresponding to the portion and functions as a locking portion for locking the collet 12. In this case, an inclined surface 11e is formed on the joint body 11 so that the tapered portion 12b on the rotating action portion 11a side of the collet 12 comes into contact with each other and is in sliding contact with each other.

Further, as shown in FIG. 3C, in another example 3 of the diameter-reducing blocking portion, the diameter-reducing blocking portion is the annular convex provided on the joint body 11 of the other example 1 of the diameter-reducing blocking portion. Article 18b (The annular ridge 18d provided on the nut 13 is used instead of FIG. 3A. The annular ridge 18d is formed by the tapered portion 13b (see FIG. 3A) of the nut 13. Similar to the annular ridge 18b provided on the joint body 11, the collet 12 is provided at the place where the collet 12 is provided so as to face the axial end surface of the collet 12, and the groove-shaped recess 12e of the collet 12 can be inserted. It is formed corresponding to the groove-shaped recess 12e.

The groove-shaped recesses 12e of the collet 12 are provided in an annular shape centered on the collet shaft over the entire circumference of the end faces on both sides in the axial direction of the collet 12 (see FIG. 3C). By entering and locking the groove-shaped recess 12e, it functions as a diameter reduction blocking portion. Also in this case, the inclined surface 11e is formed on the joint body 11 so that the tapered portion 12b on the rotating action portion 11a side of the collet 12 comes into contact with each other and is in sliding contact with each other.

As shown in the examples shown in FIGS. 3 (b) and 3 (c), in the configuration in which the diameter reduction blocking portion is formed on the nut 13, the inclined surface 11e of the joint body 11 and the tapered portion 12b of the collet 12 are in contact with each other. As the nuts 13 are tightened, the tapered portion 12c side of the collet 12 is fixed, and only the tapered portion 12b side of the collet 12 is pushed toward the pipe P side on the entire peripheral surface and narrowed down. And the diameter is reduced.
Each of the diameter-reduced blocking portions (annular recess 18a, annular convex 18b, annular recess 18c, annular convex 18d) described above locks the collet 12 formed in the joint body 11 or the nut 13. Functions as a locking part.

As shown in FIGS. 1, 2 (a) and 1 (b), a recess is formed on the outer peripheral surface of the core material 14 of the present embodiment at a position corresponding to a position where the collet 12 is crimped to the pipe P when the diameter of the collet 12 is reduced. 19 is provided.
In the concave portion 19, in the present embodiment, the convex portion 12d formed on the inner peripheral surface of the collet 12 and protruding toward the pipe P side is tightened by the nut 13 attached to the joint body 11, and the collet 12 is contracted. It has a diameter and is formed at a position on the inner surface of the pipe P corresponding to the biting position when biting over the entire outer peripheral surface of the pipe P penetrating the collet 12 (see FIG. 2B). By providing the recess 19, the pipe P can be reliably sandwiched and fixed when the diameter of the collet 12 is reduced. The position where the recess 19 is provided may overlap with the position where the water-stopping O-ring 15 of the core material 14 is mounted (see FIGS. 2A and 2B).

In the present embodiment, each convex portion 12d of the collet 12, which is a portion where the collet 12 is crimped to the pipe P when the diameter of the collet 12 is reduced, is formed with a sharp tip. Since the tip of each convex portion 12d is formed to be sharp, when the collet 12 is crimped to the pipe P when the diameter of the collet 12 is reduced, each convex portion 12d is surely placed on the entire outer peripheral surface of the pipe P. It can be made to bite (see Fig. 2 (b)). Therefore, when the diameter of the collet 12 is reduced, the pipe P penetrating the collet 12 is tightened between the collet 12 and the core material 14 with a small diameter reduction amount of the collet 12, that is, a small amount of nut 13. The amount can securely fix the tube P.
The diameter reduction blocking portion is not limited to the above-mentioned example, and when the nut 13 is tightened, the shaft of the collet 12 is prevented from reducing the diameter on one side in the axial direction of the collet 12 as the nut 13 is tightened. It suffices if the diameter can be reduced only on the other side of the direction.

Further, even if the tapered portions 12b and 12c of the collet 12, the tapered portions 13b of the nut 13 and the inclined surfaces 11c of the joint body 11 have the same taper angle and inclination angle between the surfaces that are in contact with each other and are in sliding contact with each other. It may be different, and further, one may be composed of a tapered surface and an inclined surface, and the other may be composed of a tapered surface and a corner portion which is not an inclined surface (for example, a corner portion of a cube).
Further, the taper angles and inclination angles of the tapered portions 12b and 12c of the collet 12, the tapered portions 13b of the nut 13 and the inclined surfaces 11c of the joint body 11 which are in contact with each other and are in sliding contact with each other are relative to the axial direction. The angle may be larger, for example, on the side of the nut 13 and the joint body 11, and in this case, the nut 13 can be tightened with a smaller tightening amount.

10: Pipe joint, 11: Joint body, 11a: Rotating part, 11b: Male thread part, 11c: Inclined surface, 12: Collet, 12a: Central part, 12b, 12c: Tapered part, 12d: Convex part, 12e: Grooved recess, 13: Nut, 13a: Female threaded part, 13b: Tapered part, 13c: Rotating part, 14: Core material, 15: O-ring, 16: Pipe socket, 17: Notch, 18a: Annular recess (diameter reduction blocking part), 18b: Annular ridge (diameter reduction blocking part), 18c: Circular recess (diameter reduction blocking part), 18d: Circular ridge (diameter reduction blocking part), 19: Recess, P: Pipe, d: Gap space, s: Nut tightening amount.

Claims (4)

By tightening the nut screwed to the outer peripheral surface of the joint body, the pipe is inserted and the annular collet arranged inside the nut is reduced in diameter to tighten the pipe and hold the pipe. ,
The collet is a collet that have a structure that both sides in the axial direction can be reduced in diameter when the state tightened,
The pipe joint is provided with a diameter reduction blocking portion that prevents the diameter reduction operation of the collet on one side in the collet axial direction when the nut is tightened .
The diameter reduction blocking portion is a locking portion formed on the joint body or the nut to lock the collet.
The reduced diameter of the collet when the nut is tightened is such that the collet of the collet moves with the movement of the inclined surface formed on the nut or the joint body along the inclined surface formed on the outer peripheral surface of the collet. axially made in the other side only, the collet axial one side of the collet during tightening of the nut is not reduced in diameter, that are structured as, pipe fitting, characterized in that. The pipe joint according to claim 1, wherein the collet is formed in a symmetrical shape in which both sides in the collet axial direction are symmetrical with the center in the collet axial direction as a boundary. The joint body includes a core material into which the pipe is inserted on the outer peripheral side.
The pipe joint according to claim 1 or 2 , wherein a recess is provided on the outer peripheral surface of the core material at a position corresponding to a position where the collet is crimped to the pipe when the diameter of the collet is reduced. The pipe joint according to any one of claims 1 to 3 , wherein the portion where the collet is crimped to the pipe when the diameter of the collet is reduced has a sharp tip.

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