JP6420882B2 - Synthetic resin pipe fittings - Google Patents

Description

  The present invention relates to a synthetic resin pipe joint used as a connection structure of a synthetic resin tube, which is a fluid device such as a pump, a valve, and a filter, or a fluid path.

  2. Description of the Related Art Conventionally, tubes and pipe joints made of a synthetic resin such as a fluororesin have been employed in piping paths that require chemical resistance such as semiconductor manufacturing apparatuses and liquid crystal manufacturing apparatuses. As such a pipe joint, it is provided with a joint body attached to the distal end portion of the tube, and a union nut having a female thread part fastened to a male thread part formed on the outer periphery of the joint body, and the union nut is attached to the outer periphery of the joint body. A structure having a structure that secures the sealing performance between the joint body and the tube by tightening to the joint is often used.

  For example, in the resin pipe joint described in Patent Document 1, the distal end portion of a synthetic resin tube (pipe material) has a bulging portion whose inner peripheral portion is a fluid passage and bulges radially outward. An inner ring (fitting part) is press-fitted. The tube whose diameter is expanded and deformed by press-fitting the bulging portion of the inner ring is inserted into the receiving port of the joint body. In this state, the tube is pressed in the axial direction together with the inner ring by the union nut by screwing the female thread portion formed on the inner periphery of the union nut (push wheel) to the external thread portion formed on the outer periphery of the joint body. The tube is connected to the joint body.

  In order to secure good sealing performance in the above structure, it is necessary to manage the tightening amount of the union nut with respect to the joint main body to an appropriate value. As a management method of this tightening amount, there are known a method of managing the tightening torque while tightening the union nut little by little using a tool such as a spanner, and a method of managing by repeatedly measuring the tightening dimension with a gap gauge or the like. Yes.

JP-A-10-54489

In recent years, semiconductor manufacturing apparatuses and the like have been miniaturized, and the degree of integration of components installed in the apparatus has increased. For this reason, there is a present situation that the operator is forced to manage the tightening amount of the union nut by searching in a narrow space.
In addition, the following problems arise in each of the above tightening amount management methods. That is, in the tightening torque management method, a torque error occurs for each tool to be used, and therefore, the tightening amount tends to vary. Also, in the gap size management method, since the distance traveled in the axial direction with respect to the rotation angle of the union nut is very small, there is an individual difference depending on the worker at which point the tightening is completed, and the tightening amount tends to vary. .
This invention is made | formed in view of such a situation, and it aims at providing the synthetic resin pipe joint which can manage the clamping amount of a union nut appropriately.

  In order to achieve the above object, the synthetic resin pipe joint of the present invention includes an inner ring in which a bulging portion that is press-fitted into a distal end portion of a synthetic resin tube protrudes from the outer periphery of one end portion in the axial direction, An annular seal groove into which the other axial end of the inner ring is press-fitted is formed on the inner peripheral side in a state where the bulging part is press-fitted into the distal end of the tube, and a male screw part is formed on the outer periphery. A synthetic resin joint body formed on the inner periphery and a female thread portion that is tightened to the male thread portion of the joint body in a state in which the other axial end of the inner ring is press-fitted into the seal groove. A synthetic resin pipe joint having a first opposing surface that is perpendicular to the axial direction on the joint body side, and the union nut side includes the first nut. 1 Opposes the facing surface Two opposing surfaces are provided, one of the first opposing surface and the second opposing surface, provided on one opposing surface, projecting toward the other opposing surface, and on the other opposing surface And an engagement recess that engages with the engagement projection when the union nut is tightened to an appropriate position.

  According to the present invention, when the union nut is tightened to an appropriate position, the engaging convex portion is engaged with the engaging concave portion. It can be easily confirmed that Thereby, tightening management of a union nut can be performed appropriately.

  In the synthetic resin pipe joint, it is preferable that the engaging convex portion is in contact with the other facing surface before the engaging convex portion is engaged with the engaging concave portion. In this case, when the union nut is tightened to a position before the proper position, the engagement protrusion is brought into contact with the opposing surface, and the tightening resistance is increased. It can be easily confirmed.

The synthetic resin pipe joint is provided to protrude toward the one opposing surface at a position adjacent to the engaging recess on the other opposing surface, and the engaging convex portion is engaged with the engaging concave portion It is preferable to further include a restricting portion that restricts screwing in the tightening direction.
In this case, since the union nut can be further tightened from the proper position by the restricting portion, when the union nut tightening amount becomes an appropriate value, the tightening can be reliably completed. .

The synthetic resin pipe joint is provided at a predetermined position on the outer periphery on the joint main body side, provided at a predetermined position on the outer periphery on the union nut side with a first projecting portion protruding radially outward, A second projecting portion projecting in a direction, and the first projecting portion and the second projecting portion are positioned at a circumferential position when the engaging projecting portion is engaged with the engaging recess. It is preferable that they are arranged so as to coincide.
In this case, when the union nut is tightened to an appropriate position, the circumferential positions of the first protruding portion and the second protruding portion coincide with each other. It can be more easily confirmed that an appropriate value has been reached. In addition, when checking the tightening amount, it is easy to confirm that the union nut is in the proper position by visually checking that the circumferential positions of the first and second protrusions match each other. Therefore, the inspection work becomes easy.

The first projecting portion has a joint body side end surface that is a part of the first opposing surface, and the engaging convex portion or a part of the engaging concave portion provided on the first opposing surface is the It is preferably formed on the end surface of the joint body.
In this case, since the engaging convex part or the engaging concave part is formed only on the joint body side end surface of the first projecting part, it is formed only on the joint body side end surface of the first opposing surface. Compared with this, the strength can be improved. Thereby, durability by the repeated use of an engaging convex part or an engaging concave part can be improved.

The second projecting portion has a union nut side end surface which is a part of the second facing surface, and the engaging convex portion or a part of the engaging concave portion provided on the second facing surface is It is preferable that it is formed on the union nut side end face.
In this case, since the engaging convex part or the engaging concave part is formed only on the end face on the union nut side of the second protruding part, it is formed only on the end face other than the union nut side of the second facing face. Compared with this, the strength can be improved. Thereby, durability by the repeated use of an engaging convex part or an engaging concave part can be improved.

  According to the synthetic resin pipe joint of the present invention, it is possible to properly manage the tightening amount of the union nut.

It is sectional drawing which shows the synthetic resin pipe joint which concerns on 1st Embodiment of this invention. It is a side view which shows the coupling main body of the said synthetic resin pipe couplings. It is a top view which shows the said coupling main body. It is a side view which shows the union nut of the said synthetic resin pipe joints. It is a bottom view which shows the said union nut. It is a perspective view which shows the state in the middle of the fastening of the said union nut. It is a perspective view which shows the state which tightened the said union nut to the appropriate position. It is sectional drawing which shows the synthetic resin pipe joint which concerns on 2nd Embodiment of this invention. It is a principal part side view which shows the synthetic resin pipe joint of FIG. It is a side view which shows the state in the middle of the fastening of the union nut in the synthetic resin pipe joint of FIG.

Hereinafter, embodiments of the synthetic resin pipe joint of the present invention will be described with reference to the drawings.
FIG. 1 is a sectional view showing a synthetic resin pipe joint according to the first embodiment of the present invention. In FIG. 1, a synthetic resin pipe joint 1 includes a synthetic resin elbow joint body 2 mounted on the outer peripheral side of the distal end portion of a synthetic resin (PFA or the like) tube 10, and an outer periphery of the joint body 2. A union nut 3 made of synthetic resin attached to the side and an inner ring 4 made of synthetic resin attached to the inner peripheral side of the tip of the tube 10 are provided. The synthetic resin pipe joint 1 of the present embodiment is used in an environment where the maximum use pressure is 0.4 MPa and the maximum use temperature is 100 ° or less.
In the present embodiment, the direction from the bent portion of the joint body 2 toward the openings at both ends is referred to as axially outward (axially outside), and the direction from the openings at both ends of the joint body 2 toward the bent portions is within the axial direction. Is called the inner side (axially inside).

The inner ring 4 is formed in a cylindrical shape, and the inner diameter thereof is set to be approximately the same as the inner diameter of the tube 10 so as not to disturb the movement of the fluid. A bulging portion 4 a that protrudes radially outward is formed on the outer periphery of the axially outer end portion (one axial end portion) of the inner ring 4. The bulging portion 4a is press-fitted into the distal end portion of the tube 10 to expand the diameter of the distal end portion.
A cylindrical seal protrusion 4 b that protrudes inward in the axial direction from the distal end of the tube 10 is formed at the inner end (the other end in the axial direction) of the inner ring 4. In addition, an inclined protrusion 4c is formed on the inner peripheral side of the seal protrusion 4b. The inclined protrusion 4c has an outer diameter that gradually decreases inward in the axial direction. The outer diameter of the seal projection 4b is set to be approximately the same as the outer diameter at the tip of the tube 10.

  The joint body 2 is made of a synthetic resin material such as PVC, PA, PP, PE, or a fluororesin (PFA or PTFE or the like). The inner diameter of the joint body 2 is set to be approximately the same as the inner diameter of the inner ring 4. A receiving portion 21 for inserting the distal end portion of the tube 10 into which the inner ring 4 is press-fitted into the joint body 2 is formed at the outer end portion in the axial direction of the joint body 2. A male screw portion 22 made of a trapezoidal screw is formed on the outer periphery of the receiving portion 21.

  A cylindrical seal tube portion 23 is formed in the joint body 2 at a radially inner side than an axially inner end portion of the receiving portion 21. An inclined surface 23 a whose inner diameter gradually increases outward in the axial direction is formed at the outer end in the axial direction of the seal cylinder portion 23. An annular seal groove 24 into which the seal protrusion 4b of the inner ring 4 is inserted is formed between the outer peripheral surface of the seal cylinder portion 23 and the inner peripheral surface of the receiving portion 21 facing the seal cylinder portion 23. . The tip of the seal projection 4b is in contact with or close to the bottom of the seal groove 24.

  The union nut 3 is formed in a cylindrical shape by a synthetic resin material such as PVC, PA, PP, PE, or a fluororesin (PFA or PTFE or the like), like the joint body 2. The inner diameter of the union nut 3 is formed to be slightly larger than the outer diameter of the tube 10, and when the fitting body 2 is attached to the distal end portion of the tube 10, the distal end portion (the diameter of the tube 10 is expanded). No part) is inserted.

  The union nut 3 has a pressing portion 31 that is formed to protrude radially inward at the axially outer end portion, and a female screw portion 32 that is formed of a trapezoidal screw formed on the inner periphery of the axially central portion. . The female thread portion 32 can be fastened to the male thread portion 22 of the joint body 2. Note that the male screw portion 22 and the female screw portion 32 of the present embodiment are formed so that the union nut 3 can be tightened with a small number of rotations (for example, 1.5 rotations) in order to manually tighten the union nut 3 as will be described later. Yes.

  With the above configuration, the union nut 3 is screwed inward in the axial direction of the joint body 2 with the seal protrusion 4b of the inner ring 4 press-fitted into the tube 10 inserted into the receiving part 21 of the joint body 2. By doing so, the tube 10 can be connected to the joint body 2. At that time, the pressing portion 31 of the union nut 3 presses the radially expanded portion 10 a swelled radially outward by the bulging portion 4 a on the outer peripheral surface of the tube 10 inward in the axial direction. As a result, the tip of the seal protrusion 4 b comes into contact with or approaches the bottom of the seal groove 24. Further, the outer peripheral surface of the inclined protrusion 4c presses against the inclined surface 23a at the outer end in the axial direction of the seal tube portion 23, and the inner peripheral surface of the seal protrusion 4b presses against the outer peripheral surface of the seal tube portion 23, thereby Since the outer peripheral surface of the portion 4b is in pressure contact with the inner peripheral surface of the receiving portion 21, the fluid sealing performance is ensured.

  As described above, according to the synthetic resin pipe joint 1 of the present embodiment, the seal protrusion 4b of the inner ring 4 is inserted into the seal groove 24 of the joint body 2, so that the inside of the seal protrusion 4b in the radial direction can be obtained. Since the sealing performance can be ensured by using the pressing force toward the outer side and the outer side, it is not necessary to strongly tighten the union nut 3 inward in the axial direction. Therefore, since the synthetic resin pipe joint 1 can sufficiently secure the sealing performance by manually tightening the union nut 3 under the above-mentioned usage environment, a tightening tool such as a spanner is not required, Work can be done easily.

  FIG. 2 is a side view showing the joint body 2. FIG. 3 is a plan view showing the joint body 2. In FIGS. 2 and 3, a substantially annular flange portion 25 is integrally formed on the outer periphery of the joint body 2 in the axial direction inward from the male screw portion 22. On the outer peripheral surface of the flange portion 25, a first protruding portion 26 protruding outward in the radial direction is integrally formed at a predetermined position in the circumferential direction. In the present embodiment, two first projecting portions 26 are formed on the outer peripheral surface of the flange portion 25 at an interval of 180 ° in the circumferential direction. Further, a flat portion 25b is formed on the outer peripheral surface of the flange portion 25 at a predetermined position in the circumferential direction.

  As shown in FIG. 2, the first protrusion 26 is formed over the entire axial length of the flange portion 25. The axially outer end surface (joint body side end surface) 26 a of the first protrusion 26 is formed on the same plane as the axially outer end surface 25 a of the flange portion 25. These both end surfaces 25a and 26a constitute a first facing surface 27 that is a surface perpendicular to the axial direction. The first opposing surface 27 is formed with an engaging recess 5 that is recessed inward in the axial direction.

  As shown in FIG. 3, the engaging recess 5 in the present embodiment is formed by cutting out the both end faces 25a and 26a. Therefore, the two engaging recesses 5 in the present embodiment are formed on the first facing surface 27 with an interval of 180 ° in the circumferential direction. The engagement recess 5 is formed as a long groove that opens in the outer peripheral surface of the first protrusion 26 in a plan view and extends radially inward. As described above, since the engagement recess 5 is partially formed on the end surface 26 a of the first protrusion 26, the engagement recess 5 is compared with the case where the engagement recess 5 is formed only on the end surface 25 a of the first facing surface 27. The strength of 5 can be improved. Thereby, durability by the repeated use of the engagement recessed part 5 can be improved.

  A restricting portion 7 that protrudes outward in the axial direction is integrally formed at a position adjacent to each engaging recess 5 on the first facing surface 27. The restricting portion 7 is disposed on the lower side of the union nut 3 in the screwing direction (the direction of arrow a in FIG. 3) with respect to each engaging recess 5. A side surface 7a on the engaging recess 5 side of the restricting portion 7 is formed on the same plane as a side surface 5a on the restricting portion 7 side of the engaging recess 5, and an abutting surface with which an engaging convex portion 6 to be described later contacts. Has been.

  FIG. 4 is a side view showing the union nut 3. FIG. 5 is a bottom view showing the union nut 3. 4 and 5, a second projecting portion 33 projecting radially outward is integrally formed on the outer periphery of the union nut 3 at a predetermined position in the circumferential direction. In the present embodiment, two second projecting portions 33 are formed on the outer peripheral surface of the union nut 3 with an interval of 180 ° in the circumferential direction.

  As shown in FIG. 4, the 2nd protrusion part 33 is formed over the axial direction full length of the union nut 3, and is used as a holding part hold | gripped when the union nut 3 is hand-tightened. The first projecting portion 26 of the joint body 2 and the second projecting portion 33 of the union nut 3 are positioned so that their positions in the circumferential direction coincide with each other when an engaging convex portion 6 described later is engaged with the engaging concave portion 5. (See FIG. 7).

  An end surface (union nut side end surface) 33a on the axially inner side (lower side in the drawing) of the second protrusion 33 is formed on the same plane as the axially inner end surface 3a of the union nut 3. These both end faces 3a and 33a constitute a second facing surface 34 that is a surface perpendicular to the axial direction and faces the first facing surface 27 (see also FIG. 1). The second opposing surface 34 is integrally formed with an engaging convex portion 6 that protrudes inward in the axial direction.

  As shown in FIG. 5, the engagement convex portion 6 in the present embodiment is formed to extend radially inward from the radial outer end of the end surface 33 a of the second projecting portion 33 to the end surface 3 a of the union nut 3. . Therefore, the two engaging convex portions 6 in the present embodiment are formed on the second facing surface 34 at intervals of 180 ° in the circumferential direction. As described above, since the engaging convex portion 6 is partially formed on the end surface 33a of the second projecting portion 33, the engaging convex portion 6 is engaged compared to the case where it is formed only on the end surface 3a of the second facing surface 34. The strength of the convex portion 6 can be improved. Thereby, durability by repeated use of the engaging convex part 6 can be improved.

  The engaging convex part 6 can be engaged with the engaging concave part 5 on the joint body 2 side. The amount of protrusion of the engaging convex portion 6 inward in the axial direction is set so as to abut on the first facing surface 27 immediately before the engaging convex portion 6 engages with the engaging concave portion 5 (front side). The engaging convex portion 6 has a side surface 6 a that abuts against the abutting surface 7 a of the restricting portion 7 when engaged with the engaging concave portion 5.

Next, the tightening procedure of the union nut 3 will be described with reference to FIGS.
After the hand-tightening of the union nut 3 with respect to the joint body 2 is started, as shown in FIG. 6, the union nut 3 is engaged immediately before the proper position where the tightening amount is appropriate, that is, the engagement convex portion 6 is engaged. When the screw is screwed up just before engaging with the mating recess 5, the front end surface of the engaging projection 6 abuts against the first facing surface 27. Thereby, since the fastening resistance of the union nut 3 increases rapidly, the operator can more easily confirm that the union nut 3 has been tightened just before the proper position.

  Thereafter, when the union nut 3 is further tightened against the tightening resistance, the engaging convex portion 6 is screwed together with the union nut 3 while being in sliding contact with the first facing surface 27, and as shown in FIG. 5 is engaged. At this time, since the engaging convex portion 6 is released from the sliding resistance with the first facing surface 27, the tightening resistance of the union nut 3 rapidly decreases. Thereby, the operator can easily confirm that the tightening amount of the union nut 3 has become an appropriate value, and can perform tightening management of the union nut 3 appropriately.

  Further, when the engaging convex portion 6 is engaged with the engaging concave portion 5, the circumferential position of the first projecting portion 26 coincides with the circumferential position of the second projecting portion 33. Therefore, it is possible to more easily confirm that the tightening amount of the union nut 3 has become an appropriate value by visually confirming the coincident state. Further, when periodically checking the tightening amount of the union nut 3, it is visually confirmed that the circumferential positions of the first protruding portion 26 and the second protruding portion 33 coincide with each other. Since it can be easily confirmed that is in an appropriate position, inspection work is also facilitated.

  Further, when the engaging convex portion 6 is engaged with the engaging concave portion 5, the side surface 6 a of the engaging convex portion 6 contacts the contact surface 7 a of the restricting portion 7. Accordingly, the union nut 3 can be restricted from further screwing in the tightening direction from an appropriate position, and therefore, when the union nut 3 is tightened to an appropriate value, the tightening is surely completed. Can do.

FIG. 8 is a sectional view showing a synthetic resin pipe joint according to the second embodiment of the present invention. FIG. 9 is a side view of an essential part showing the synthetic resin pipe joint. 8 and 9, in the synthetic resin pipe joint 1 of the present embodiment, an annular gauge ring 8 is separately attached to the outer periphery of the straight type joint body 2 instead of the flange portion.
In the present embodiment, the direction from the axially central portion of the joint body 2 toward the openings at both axial ends is referred to as axially outward (axially outer side). A direction toward the central portion in the axial direction is referred to as an axially inner side (inward in the axial direction).

  A plurality of elongated holes 8a extending along the circumferential direction are formed in the gauge ring 8 at predetermined intervals. An end surface 8 b on the outer side in the axial direction of the gauge ring 8 is a first facing surface 27 that faces the second facing surface 34 of the union nut 3. On the first facing surface 27 of the gauge ring 8, an engaging convex portion 6 that protrudes outward in the axial direction is integrally formed at a position corresponding to the central portion in the longitudinal direction of the long hole 8a.

  On the other hand, on the second opposing surface 34 of the union nut 3, an engagement recess 5 is formed in which the engagement projection 6 is engaged. The second facing surface 34 is integrally formed with protruding portions 9 that protrude inward in the axial direction at adjacent positions on both sides in the circumferential direction of the engaging recess 5. The remaining configuration of the present embodiment is the same as that of the first embodiment, and thus the description thereof is omitted.

Next, the tightening procedure of the union nut 3 of this embodiment will be described with reference to FIGS.
After the hand-tightening of the union nut 3 with respect to the joint body 2 is started, as shown in FIG. 10, the union nut 3 is engaged immediately before the proper position, that is, the engaging convex portion 6 is engaged with the engaging concave portion 5. When the screw is advanced to just before, the protruding portion 9 comes into contact with the tip of the engaging convex portion 6. Thereby, the operator can easily confirm that the union nut 3 has been tightened to just before the proper position.

  Thereafter, when the union nut 3 is further tightened, the protruding portion 9 gets over the engaging convex portion 6 and is engaged with the engaging concave portion 5. When climbing over the engaging projection 6, the tightening resistance of the union nut 3 rapidly increases, and when the protrusion 9 is climbed over, the tightening resistance of the union nut 3 rapidly decreases. Thereby, the operator can easily confirm that the tightening amount of the union nut 3 has become an appropriate value, and can perform tightening management of the union nut 3 appropriately.

The present invention is not limited to the above embodiment. For example, in the first embodiment, the engagement concave portion 5 is provided on the joint body 2 side, and the engagement convex portion 6 and the restriction portion 7 are provided on the union nut 3 side. However, the engagement convex portion is provided on the joint main body 2 side. 6 and the restricting portion 7 may be provided, and the engaging recess 5 may be provided on the union nut 3 side.
Moreover, in the said 2nd Embodiment, although the engagement convex part 6 is provided in the joint main body 2 side and the engagement recessed part 5 and the projection part 9 are provided in the union nut 3 side, the engagement recessed part 5 is provided in the joint main body 2 side. And the protrusion part 9 may be provided and the engagement convex part 6 may be provided in the union nut 3 side. Moreover, the synthetic resin pipe joint 1 of the second embodiment may include the first projecting portion 26, the second projecting portion 33, or the restricting portion 7 as in the first embodiment. Further, the joint body 2 of the first embodiment may have other shapes such as a straight type in addition to the elbow type, and the joint body 2 of the second embodiment may have other shapes such as an elbow type in addition to the straight type. It may be a shape.

DESCRIPTION OF SYMBOLS 1 Synthetic resin pipe joint 2 Joint main body 3 Union nut 4 Inner ring 4a Expansion part 5 Engagement recessed part 6 Engagement convex part 7 Control part 8 Gauge ring 10 Tube 22 Male thread part 24 Seal groove 26 1st protrusion part 26a End surface ( (Fitting body side end face)
27 1st opposing surface 32 Female thread part 33 2nd protrusion part 33a End surface (Union nut side end surface)
34 Second facing surface

Claims (3)

An inner ring formed by projecting a bulging portion that is press-fitted into the distal end portion of the synthetic resin tube into the outer periphery of one axial end portion;
An annular seal groove into which the other axial end of the inner ring is press-fitted is formed on the inner peripheral side in a state where the bulging part is press-fitted into the distal end portion of the tube, and a male screw portion is provided on the outer periphery. A formed synthetic resin joint body;
A synthetic resin union nut having a female threaded portion formed on the inner periphery of a female threaded portion that is fastened to the male threaded portion of the joint body in a state in which the other axial end of the inner ring is press-fitted into the seal groove. A pipe joint,
Wherein the fitting body side, I perpendicular Mendea to the axial direction, the first opposed surface including an end surface of the fitting body is provided,
The union nut side is provided with a second facing surface that faces the first facing surface and includes an end surface of the union nut ,
An engaging projection provided on one of the first and second opposing surfaces and projecting toward the other opposing surface;
An engagement recess that is provided on the other facing surface and engages with the engagement projection when the union nut is tightened to an appropriate position ;
A first protrusion provided at a predetermined position on the outer periphery of the joint body side and protruding radially outward;
A second projecting portion provided at a predetermined position on the outer periphery of the union nut side and projecting radially outward;
The first projecting portion and the second projecting portion are arranged so that their circumferential positions coincide with each other when the engaging convex portion is engaged with the engaging concave portion,
The first protrusion has a joint body-side end surface that is a part of the first facing surface,
A part of the engaging convex part or the engaging concave part provided on the first facing surface is formed on the end face of the joint body, and the other part of the engaging convex part or the engaging concave part of the joint main body is formed. Formed on the end face,
The second protrusion has a union nut side end surface which is a part of the second facing surface,
A part of the engaging convex part or the engaging concave part provided on the second facing surface is formed on the end face on the union nut side, and the other part of the engaging convex part or the engaging concave part is the union nut. A synthetic resin pipe joint formed on the end face . The engagement convex portion is formed with the end surface of the joint main body on which the engagement concave portion is formed and the end surface of the joint main body or the engagement concave portion before the engagement convex portion is engaged with the engagement concave portion. The synthetic resin pipe joint according to claim 1, wherein the union nut side end surface and the end surface of the union nut are in contact with each other . Protruding toward the one opposing surface at a position adjacent to the engaging recess on the other opposing surface, and the engaging convex portion is screwed in the tightening direction from the state engaged with the engaging concave portion. The synthetic resin pipe joint according to claim 1, further comprising a restriction portion for restricting the pressure .

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