JP2005133742A - Joint - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a joint capable of regulating screwing of a push ring into a joint body in a temporary fastening state and regulating screwing of the push ring away from the joint body in a regular fastening state. <P>SOLUTION: The joint comprises the joint body 13 with an approximately cylindrical shape, and the push ring 14 engaged with the joint body 13. A groove 61 formed by serration processing is arranged on a screw-thread 60 of a second male screw section 34 screw-carved on the push ring 14. Burrs 62 caused by this serration processing are formed on slant faces 63 of the screw threads 60. The grove 61 regulates screwing of the push ring 14 into the joint body 13 in a temporary fastening state in which the push ring 14 is manually fastened to the joint body 13. The groove 61 regulates screwing of the push ring 14 away from the joint body 13 in a regular fastening state in which the push ring 14 is fastened to the joint body 13 with a wrench. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a pipe joint used for water pipes, cold / hot water pipes, floor heating, load heating, and the like.

  Conventionally, the following structure is known as a structure of a joint connected to a pipe such as a water pipe (see, for example, Patent Document 1). The joint includes a joint body, a cap that is screwed onto the joint body, a retaining member that restricts the pipe from being pulled out, and a collar that is disposed between the joint body and the cap. A seal member is provided between the outer peripheral surface of the joint main body of the joint and the inner peripheral surface of the cap or between the inner peripheral surface of the joint main body and the outer peripheral surface of the cap. Has the effect of stopping.

Moreover, what is shown below as a coupling which does not use a sealing member is known (for example, refer patent document 2). This joint includes a restricting means for restricting the main body and the pipe from coming out, and a push ring screwed into the joint main body. A locking protrusion is provided on the flat portion provided at the proximal end of the male screw portion formed on the push ring or the main body of the joint. This locking projection restricts the threading of the push ring into the main body, and in the final tightened state where the push ring is tightened against the main body with a force that deforms the locking projection, It is the structure which controls retraction.
JP 2001-159492 A (pages 5 and 6, FIG. 2) Japanese Patent Laid-Open No. 2002-257273 (second and seventh terms, FIG. 2)

  However, in the technique described in Patent Document 1, the seal member provided between the outer peripheral surface of the joint main body and the inner peripheral surface of the cap or between the inner peripheral surface of the joint main body and the outer peripheral surface of the cap is a rubber material. Since it is manufactured, the resistance is weak, and it has not been possible to obtain a sufficient function as a restriction of screwing in the temporarily tightened state of the cap and as a locking prevention in the fully tightened state of the cap.

  Further, in the technique described in Patent Document 2, the locking protrusion provided on the flat portion of the base end of the external thread portion formed on the outer surface of the push ring or the main body is screwed into the main body in the temporarily tightened state. Can be regulated. However, in the final tightening state in which the push ring is fastened to the main body with such a large force that the locking protrusion is deformed, there is a problem that the locking protrusion is crushed and the regulating force as a locking prevention cannot be exhibited.

  The present invention has been made paying attention to such problems existing in the prior art. The purpose is to provide a joint that can restrict the screwing of the push ring in the temporarily tightened state and can regulate the screwing of the push wheel in the final tightened state.

  In order to achieve the above-mentioned object, the joint of the present invention according to claim 1 has a tubular shape, a joint body into which a pipe can be inserted, and a pipe that is disposed and inserted in the joint body. A joint provided with a restricting means that engages with the outer peripheral surface to restrict the pipe from coming out of the joint body and a push ring that is screwed to the joint body and prevents the pipe from coming out of the joint body. The inner surface of the joint body is provided with a female thread, the outer peripheral surface of the push ring is provided with a male thread part that is screwed into the female thread part of the joint body, and one or a plurality of threads are formed on the thread of the male thread part. Serration processing is performed to form grooves, and in the temporarily tightened state where the press ring is temporarily tightened against the joint body, the screw ring is restricted from being screwed into the joint body, and the final tightening is performed by tightening the press ring against the joint body. In this state, the push ring is not screwed into the joint body. It was adapted to the gist of the.

  The joint of the invention of claim 2 is the joint of the invention of claim 1, wherein the serration is applied in the axial direction of the press ring, and the thread groove formed after the serration is The gist of the invention is that it extends in the axial direction and a flash is formed on the slope of the thread.

  According to a third aspect of the present invention, there is provided a joint according to the second aspect of the present invention, wherein the number of the grooves is 20 to 50 on the circumference of the male thread portion of the push ring.

According to the present invention, the following effects can be exhibited.
According to the joint of the first aspect of the present invention, it is possible to restrict the screwing of the push ring in the temporarily tightened state of the push ring to the joint body, and to regulate the screwing of the push ring in the final tightened state. it can.

  According to the joint of the invention described in claim 2, in addition to the effect of the invention described in claim 1, the restriction force of the screw retraction in the final tightening state is increased by the flash formed on the slope of the thread. be able to.

  According to the joint of the invention described in claim 3, in addition to the effect of the invention described in claim 2, the tightening force suitable for restricting the screwing in the temporary tightening state and the screwing out in the final tightening state It is possible to obtain a tightening force suitable for the regulation.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
As shown in FIG. 4, the pipe 11 is formed in a cylindrical shape from a synthetic resin such as polyolefin (crosslinked polyethylene, polybutene, etc.), and is used for plumbing of waterworks. A joint body 13 constituting the joint 12 is formed in a substantially cylindrical shape by a metal such as an alloy (brass, bronze, etc.), and a push ring 14 that is also formed in a substantially cylindrical shape by the metal is formed at the tip portion on the left side in FIG. It is designed to be screwed.

  A first male screw portion 15 is formed on the outer peripheral surface of the base end portion of the joint body 13 and can be screwed with a pipe body such as a water pipe. A nut portion 16 is formed on the outer peripheral surface of the distal end portion of the joint body 13. Then, the joint body 13 and the pipe body are easily screwed together and released by engaging a work tool such as a spanner with the outer peripheral surface of the nut portion 16 and rotating the joint body 13.

  Inside the joint body 13, a pair of lock rings 22 are disposed as restricting means for restricting the pipe 11 from coming out of the joint body 13. Both lock rings 22 protrude from the base ring 23 with the same length as a ring made of metal such as stainless steel, and in the insertion direction of the pipe 11 toward the inside of the base ring 23. It comprises a plurality of restricting pieces 24 that are inclined. In addition, a spacer 25 made of metal such as stainless steel is interposed between the lock rings 22. The width of the spacer 25 corresponds to the width of the base ring 23 of the lock ring 22.

  On the inner peripheral surface of the intermediate portion of the joint body 13, an annular inclined surface 26 is formed that is inclined so as to increase in diameter toward the tip of the joint body 13. A receiving surface 27 with which the base ring 23 of the lock ring 22 abuts is formed in an annular shape on the inner peripheral surface on the distal end side of the joint body 13 with respect to the inclined surface 26 so as to be orthogonal to the axis of the joint body 13. Of the pair of lock rings 22, the lock ring 22 positioned on the proximal end side of the joint body 13 is engaged with the base ring 23 on the receiving surface 27, and both the restricting pieces 24 are connected to the inclined surface 26. Are arranged so as to have a gap between them.

  As shown in FIG. 2A and FIG. 3A, the contact surface 18 and the inclined surface 26 provided in an annular shape so as to be orthogonal to the axis of the joint body 13 on the inner peripheral surface of the joint body 13. In the meantime, the first groove portion 28 and the second groove portion 29 are recessed so as to extend in the circumferential direction in order from the proximal end side of the joint body 13. The first groove portion 28 and the second groove portion 29 are fitted with a seal ring 30 having a circular cross section as a seal member, respectively, and the outer peripheral surface of the pipe 11 inserted into the joint body 13 and the inner periphery of the joint body 13. It is designed to seal between the surfaces.

  As shown in FIGS. 4 and 2A, a first female thread portion 17 is formed on the inner peripheral surface of the nut portion 16 that is the distal end side of the joint body 13. As shown in FIG. 5, the contact surface 18 provided at the intermediate portion in the joint body 13 regulates the insertion of the pipe 11 at a predetermined position when the pipe 11 is inserted into the joint body 13. Yes. An introduction path 19 is provided inside the joint body 13 from the abutment surface 18 so that when the joint body 13 is screwed into the pipe body, a liquid as a transport fluid flows in the introduction path 19. It has become.

  When the end portions of the pipe 11 are inserted inside the pair of lock rings 22, the restricting pieces 24 positioned in the two stages slightly expand outward, and the tip ends thereof are engaged with the outer periphery of the pipe 11 in two stages. The As a result, the escape of the pipe 11 from the joint body 13 is restricted. On the outer peripheral surface of the base end portion of the joint main body 13, a display groove as a confirmation means that indicates a predetermined insertion depth of the pipe 11 into the joint main body 13 at the distal end side of the joint main body 13 relative to the first male screw portion 15. 20 is provided. The display groove 20 is cut by cutting over the entire outer peripheral surface so as to be orthogonal to the axis of the joint body 13. The display groove 20 has a substantially V-shaped cross section, and the deepest portion 21 is located on the extended surface of the contact surface 18.

  As shown in FIGS. 2 (a), 3 (a), and 4, the push ring 14 includes a cylindrical cylindrical portion 31 and a gripping portion formed smaller than the outer diameter of the nut portion 16 of the joint body 13. 32. An insertion hole 33 for inserting the pipe 11 through the cylindrical portion 31 and the grip portion 32 is formed at the center of the push wheel 14. Further, a second male threaded portion 34 is formed on the outer peripheral surface of the cylindrical portion 31 and can be screwed with the first female threaded portion 17 of the joint body 13. On the outer periphery of the end of the grip portion 32, a pair of locking portions 35 are cut out at positions facing each other. A spanner is engaged with the engaging portions 35 when the push ring 14 is screwed into and released from the joint body 13.

  As shown in FIGS. 1A to 1D, a plurality of grooves 61 extending in the axial direction of the push ring 14 are formed by serrations on the thread 60 of the second male thread portion 34 of the push ring 14. . The plurality of grooves 61 are formed such that the cutting tool is depressed in a direction orthogonal to the thread 60 of the second male thread portion 34 and the thread 60 is recessed. The grooves are formed in a V-shaped cross section, and preferably 20 to 50 grooves are provided on the circumference of the second male screw portion 34. When the number is less than 20, the restriction force when the second male threaded portion 34 of the push ring 14 is fastened to the first female threaded portion 17 of the joint body 13 is low, and even the weak force of the operator can be easily screwed together. There is a possibility that the temporarily tightened state may not be formed. If there are more than 50, the restricting force when tightening the second male threaded portion 34 of the push ring 14 to the first female threaded portion 17 of the joint body 13 is too great, and the second male threaded portion 34 of the push ring 14 is There is a possibility that the first female screw portion 17 of the main body 13 cannot be screwed in at all by the hand of the operator. Further, on the slope 63 of the screw thread 60 around the groove 61, a flash 62 is formed and an edge portion 66 is formed. On the outer peripheral surface of the push ring 14, a flat portion 51 is formed by cutting over the entire circumference of the cylindrical portion 31 at the proximal end portion of the second male screw portion 34 that becomes the boundary between the cylindrical portion 31 and the gripping portion 32. Yes.

  As shown in FIGS. 2A and 2B, when the second male threaded portion 34 of the push ring 14 is screwed into the first female threaded portion 17 of the joint body 13, it is formed on the thread 60 of the second male threaded portion 34. The flash 62 is interposed between the thread valley 65 of the first female screw portion 17 and the screw thread 60 of the second male screw portion 34. Thereby, the screwing of the second male screw portion 34 into the first female screw portion 17 with a weak force, for example, the hand force of the operator or the like is restricted. This state is a temporarily tightened state. In this temporarily tightened state, further screwing of the second male screw portion 34 of the push ring 14 into the first female screw portion 17 of the joint body 13 is restricted, and a gap 54 is formed between the grip portion 32 and the joint body 13. It has become so. From the gap 54, the flat portion 51 is visible. The joint 12 includes a joint body 13, a lock ring 22 that constitutes a restricting unit, and a push wheel 14 or the like.

  As shown in FIGS. 3A and 3B, when the second male threaded portion 34 of the push ring 14 is screwed into the first female threaded portion 17 of the joint main body 13, for example, by using a wrench with a strong force, The second male screw portion 34 is screwed into the first female screw portion 17 while the flash 62a on the distal end side of the second male screw portion 34 is pressed by the screw valley 65 of the first female screw portion 17 and becomes smaller. As a result, the screw 62b on the base end side of the second male threaded portion 34 is completely screwed in while retaining its original shape. This state is the final tightening state. In this final tightened state, the flash 62 b that remains substantially in the original shape on the proximal end side of the second male screw portion 34 is between the screw valley 65 of the first female screw portion 17 and the screw thread 60 of the second male screw portion 34. The insertion of the second male screw portion 34 of the push ring 14 with respect to the first female screw portion 17 of the joint body 13 is restricted. Further, in the final tightening state, the inner end surface 32 a of the grip portion 32 of the push wheel 14 is substantially in contact with the distal end surface of the joint body 13, and no gap is formed between the grip portion 32 and the joint body 13. It is like that.

  In the temporary tightening state described above, the tightening force capable of tightening the second male screw portion 34 of the push ring 14 to the first female screw portion 17 of the joint body 13 by the hand force of the operator is 50 to 100 N · cm. Therefore, it is preferable that the screwing is regulated with a tightening force of 50 to 100 N · cm when the push ring 14 is screwed into the joint body 13. If it is lower than 50 N · cm, the second male threaded portion 34 of the push ring 14 is easily screwed into the first female threaded portion 17 of the joint body 13 even with a weak force of the operator, and the gripping portion 32 and the joint There is a possibility that the gap 54 is not formed between the main bodies 13, and there is a possibility that the temporarily tightened state is not formed. On the other hand, if it is larger than 100 N · cm, for example, it becomes difficult for an operator to screw the second male screw portion 34 of the push ring 14 into the first female screw portion 17 of the joint body 13, and tightening with a spanner is performed. There is a possibility that the push wheel 14 may fall off from the joint body 13 before performing.

  Moreover, it is preferable that the tightening with the spanner at the time of forming the final tightening state is screwed in at 1000 to 2000 N · cm. When the tightening force is lower than 1000 N · cm, the vibration of the liquid flowing in the joint body 13 and the impact generated when the liquid flowing in the pipe 11 is suddenly stopped are applied to the first female thread portion 17 of the joint body 13. There is a possibility that the second male threaded portion 34 of the push ring 14 is screwed off. Further, when it is larger than 2000 N · cm, a spanner is used for the pair of engaging portions 35 provided on the nut portion 16 and the push ring 14 formed on the outer peripheral surface of the tip portion of the joint body 13 by a spanner. There is a risk of scratching.

  As shown in FIG. 4, the in-core 36 has an insertion cylinder portion 37 formed in a cylindrical shape by a metal such as an alloy (brass, bronze, etc.), and an outer side so as to be orthogonal to the insertion cylinder portion 37 at one end thereof. It is comprised from the annular collar part 38 extended to. The length of the in-core 36 in the longitudinal direction is the same as the length from the contact surface 18 of the joint body 13 to the end surface of the push wheel 14. And the insertion cylinder part 37 is inserted in the edge part of the pipe 11, and prevents that the pipe 11 deform | transforms inside by heat etc. FIG. The outer peripheral surface 39 on the other end side of the insertion cylinder portion 37 is formed in a tapered surface shape whose diameter is reduced toward the end portion, so that the in-core 36 can be easily inserted into the pipe 11.

  Next, the operation of the joint 12 configured as described above will be described. In order to assemble the joint 12, first, a pair of lock rings 22 with spacers 25 are inserted into the joint body 13, and the second male thread portion 34 of the push ring 14 is inserted into the joint body 13 by the operator's hand. 1 Tighten the female thread portion 17 with a weak force. Then, as shown in FIGS. 2A and 2B, when the second male threaded portion 34 of the push ring 14 is screwed into the first female threaded portion 17 of the joint body 13, the thread 60 is formed. The beam 62 is interposed between the screw valley 65 of the first female screw portion 17 and the screw thread 60 of the second male screw portion 34 and cannot be screwed in with a weak force by the operator's hand. Moreover, the edge part 66 formed in the screw thread 60 of the 2nd external thread part 34 is slidably contacted with the thread valley 65 of the 1st internal thread part 17 of the coupling main body 13, and screwing is controlled. At this time, further screwing of the second male thread portion 34 of the push ring 14 into the first female thread portion 17 of the joint body 13 is restricted, and the push ring 14 is temporarily tightened with respect to the joint body 13. The operator can confirm that the flat portion 51 is in the temporarily tightened state by visually recognizing the flat portion 51 from the gap 54 formed between the grip portion 32 of the push wheel 14 and the joint body 13. This temporarily tightened state is a state in which the push ring 14 is only tightened with a weak force by the operator's hand with respect to the joint body 13 and may be a state before being tightened using a tool such as a spanner. It is formed so that it can be understood by workers.

  In order to make the push ring 14 into the final tightening state with respect to the joint body 13, first, the spanner is locked to the grip portion 32 of the push ring 14, and the second male thread portion 34 of the push ring 14 is connected to the first female thread of the joint body 13. Tighten with a strong force so that it can be screwed into the part 17. Then, the second male screw portion 34 is screwed into the first female screw portion 17 while the flash 62 a on the distal end side of the second male screw portion 34 is cut by the thread valley 65 of the first female screw portion 17 and becomes smaller. At this time, the flash 62b on the base end side of the second male screw portion 34 has little contact with the thread valley 65 of the first female screw portion 17, so that the screw engagement is completed while maintaining the original shape, and a final tightening state is obtained. Moreover, the edge part 66 formed in the screw thread 60 of the 2nd external thread part 34 becomes resistance with respect to the thread valley 65 of the 1st internal thread part 17 of the coupling main body 13, and screwing out is controlled.

  In this final tightened state, the flash 62b on the proximal end side of the second male screw portion 34 remains in its original shape, and therefore is interposed between the screw thread 60 of the second male screw portion and the screw valley 65 of the first female screw portion, The retraction of the second male screw portion 34 of the push ring 14 with respect to the first female screw portion 17 of the joint body 13 is restricted. In the step of forming the temporary tightening state and the step of forming the final tightening state, the press ring 14 is assembled to each of a large number of joint bodies 13, and the step of forming the final tightening state from the step of forming the temporary tightening state. Moved to.

  Further, in the joint 12, the tip end surface of the cylindrical portion 31 of the push ring 14 restricts the pair of lock rings 22 from coming out of the joint 12. Then, after the joint 12 is brought into the final tightening state, the first male screw portion 15 is screwed with a pipe body such as a water pipe, and the pipe 11 is inserted into the joint 12.

  At this time, if the joint 12 is in the final tightened state, the gap 54 is not formed between the joint main body 13 and the gripping portion 32, and the operator visually confirms that the joint 12 is in the final tightened state. Can be confirmed quickly. If the gap 54 is formed between the inner end surface 32a of the gripping portion 32 of the push ring 14 and the tip end surface of the joint body 13 and the flat portion 51 is visible, the joint 12 is in a temporarily tightened state. When it is confirmed that the above operation is repeated, the joint 12 in the temporarily tightened state is brought into the final tightened state.

  Next, in order to insert the pipe 11 into the joint 12, first, the insertion tube portion 37 of the in-core 36 is inserted into the end portion of the pipe 11. Subsequently, the outer end surface 40 of the flange portion 38 of the in-core 36 is made to correspond to the extended line of the deepest portion 21 of the display groove 20, and the outer peripheral surface of the pipe 11 is arranged along the outer peripheral surface of the joint body 13. After that, on the outer peripheral surface of the pipe 11, a line 41 is marked with an oil pen or the like at a position corresponding to the extended line of the end surface of the push wheel 14, and the end of the pipe 11 on the side where the in-core 36 is inserted is inserted. The hole 33 is inserted into the joint body 13.

  As shown in FIG. 4, when the outer end surface 40 of the flange portion 38 of the incore 36 reaches the contact surface 18, the line 41 on the outer peripheral surface of the pipe 11 is located at the same position as the end surface of the push ring 14, and The outer end surface 40 of the flange portion 38 is brought into contact with the contact surface 18. When the pipe 11 is inserted into the joint body 13, the pair of seal rings 30 seals between the outer peripheral surface of the pipe 11 and the inner peripheral surface of the joint body 13. Further, when the end portions of the pipe 11 are inserted inside the pair of lock rings 22, the restricting pieces 24 positioned in the two stages slightly expand outward, and the tip ends thereof are engaged with the outer periphery of the pipe 11 in two stages. Combined. As a result, the escape of the pipe 11 from the joint body 13 is restricted.

The effects exhibited by the above embodiment will be described below.
Of the joint main body 13 and the pusher wheel 14 constituting the joint 12 of the above-described embodiment, the second male screw part 34 threaded on the outer peripheral surface of the cylindrical part 31 of the pusher wheel 14 has a plurality of grooves 61 by serration processing. A flash 62 is formed around the groove 61. The flash 62 is interposed between the thread 60 of the second male threaded portion 34 and the thread valley 65 of the first female threaded portion 17 and is pushed into the joint body 13 with a weak tightening force by the operator's hand in the temporarily tightened state. Screwing of the cylindrical portion 31 of the wheel 14 is restricted. Further, in the final tightened state, the flash 62 is interposed between the thread 60 on the proximal end side of the second male threaded portion 34 and the thread valley 65 on the distal end side of the first female threaded portion 17, and the push ring 14 from the joint body 13. Can be controlled.

  Further, by setting the number of grooves 61 formed in the second male threaded portion 34 to 20 to 50 on the circumference of the second male threaded portion 34, a push wheel to the joint body 13 in the temporarily tightened state Accordingly, it is possible to obtain a tightening force suitable for the restriction of screwing 14 and the restriction of screwing of the push wheel 14 from the joint body 13 in the final tightening state.

In addition, this embodiment can also be changed and embodied as follows.
The grooves 61 provided in the thread 60 of the second male thread portion 34 are formed in the same number as the embodiment at an angle of approximately 45 ° with respect to the axial direction of the push ring 14 as shown in FIG. It may be. The angle of the groove 61 with respect to the axial direction of the push wheel 14 can be set to an arbitrary angle that intersects the axial direction. The number of grooves 61 can also be set to an arbitrary number.

-The number of the grooves 61 may be one.
The shape of the groove 61 can be formed in a U-shaped cross section, an arc shape in cross section, or the like.
Furthermore, the technical idea which can be grasped from the embodiment or another example will be described below.

  The joint according to claim 2 or 3, wherein the flash formed on the slope of the thread of the male screw portion is located around the groove. When comprised in this way, screwing of the push ring with respect to a joint main body can fully be controlled, and screwing of the push ring from a joint main body can fully be controlled.

  4. The joint according to claim 1, wherein the groove formed in the thread of the male screw portion extends in a direction intersecting with the axial direction of the push ring. When comprised in this way, a flash can be enlarged and the restriction | limiting of the screwing of the push ring with respect to a joint main body and the restriction | limiting of the screwing-off of a push ring from a joint main body can be performed effectively.

(A) is a plan view showing a push ring in the embodiment, (b) is a partially enlarged cross-sectional view showing a second male screw part of the push ring, (c) is a partially enlarged plan view showing a second male screw part of the push ring, (D) is a partial expanded sectional view which shows the flash formed in the screw thread of the 2nd external thread part of a press ring. (A) is a half cross-sectional view showing a temporarily tightened state of a push ring, (b) is an enlarged cross-sectional view showing a screwed portion in a temporarily tightened state. (A) is a half cross-sectional view showing the final tightening state, (b) is an enlarged cross-sectional view showing the screwed portion in the final tightening state. The disassembled perspective view which shows a coupling. The half sectional view showing the state where the pipe was inserted in the joint. Plan view of a push ring showing another example

Explanation of symbols

  DESCRIPTION OF SYMBOLS 11 ... Pipe, 12 ... Joint, 13 ... Joint main body, 14 ... Push ring, 17 ... Female thread part, 34 ... Male thread part, 22 ... Lock ring as a control means, 60 ... Screw thread, 61 ... Groove, 62 ... Burr, 63 ... Slope.

Claims (3)

A joint body that is cylindrical and into which a pipe can be inserted, and a regulating means that is disposed in the joint body and engages with the outer peripheral surface of the inserted pipe to restrict the pipe from coming out of the joint body. And a press ring that is screwed into the joint body and prevents the regulating means from coming out of the joint body.
A female thread portion is provided on the inner peripheral surface of the joint body, and a male screw portion is provided on the outer peripheral surface of the push ring. The male thread portion is threaded into the female thread portion of the joint body. In a temporarily tightened state in which a groove is formed by machining and the press ring is temporarily tightened against the joint body, the screw ring is restricted from being screwed into the joint body, and a final tightened state in which the press ring is tightened to the joint body Then, it is comprised so that the screwing-off of the push ring with respect to a joint main body may be controlled. The serration is performed in the axial direction of the press ring, and the thread groove formed after the serration extends in the axial direction of the press ring, and a burr is formed on the slope of the thread. The joint according to 1. The joint according to claim 2, wherein the number of the grooves is 20 to 50 on the circumference of the male screw portion of the push ring.

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