JP2010038267A - Resin pipe joint - Google Patents

Abstract

[PROBLEMS] To prevent the rotation of a tube associated with the turning operation of the union nut from occurring while the parts are a joint body and a union nut, and to ensure good sealing performance without causing the rotation of the tube due to the joint structure. Provide resin pipe fittings.
A fluororesin joint main body 1 having an inner cylinder portion 4 and a male screw portion 5, a nut main body 2A having a female screw portion 8 and a rotated operation portion 18, and a diameter expansion change region 9 in the diameter expansion portion 3A. And a pressing action cylinder 2B having a seal pressing part 10 acting on the small diameter side portion of the cylinder has a union nut 2 which is connected and integrated so as to be relatively rotatable, and the tube 3 is fitted on the inner cylinder part 4 Then, the nut main body 2A in a state where the expanded diameter portion 3A is formed is rotated to screw the union nut 2, and the small diameter side portion of the expanded diameter change region 9 is the seal pressing portion 10 in the axis P direction. Resin pipe joint that is configured to be pressed against.
[Selection] Figure 1

Description

  The present invention relates to a resin pipe joint having a structure in which a tube as a fluid transfer path is expanded (flared) and connected, and more specifically, in various technical fields such as semiconductor manufacturing, medical / pharmaceutical manufacturing, food processing, chemical industry, etc. It is also suitable for piping of high-purity liquid and ultrapure water handled in the manufacturing process, and relates to a resin pipe joint used as a connecting means of a tube that is a fluid device such as a pump, a valve, a filter, or a fluid transfer path. .

  As this type of resin pipe joint, a tube joint disclosed in Patent Document 1 is known. That is, the tube 1 made of synthetic resin is forcibly pushed into the inner tube portion 5 of the joint body 4 or, as shown in FIG. It fits in part 5. Then, the union nut 6 fitted in the tube in advance is screwed into the joint body, and is tightened to forcibly move in the axial direction of the joint body 4, so that the enlarged root portion 2 a of the tube 1 is edged. This is a structure in which the portion 6 a is pressed strongly in the axial direction to seal between the tube 1 and the inner cylinder portion 5.

  As the structure similar to the above-described structure, the one disclosed in FIGS. 8 and 9 of Patent Document 2 and the resin pipe joint disclosed in FIG. 6 of Patent Document 3 are known. As described above, the joint structure in which the tip of the tube is expanded (flared), fitted into the joint body, and fastened with a nut is the structure disclosed in FIG. 5 of Patent Document 2, FIG. 5 of Patent Document 3, or the like, Compared to a three-part pipe fitting that has a tube end fitted to the inner ring of the dedicated part with an expanded outer diameter fitted in the tubular receiving port of the fitting body and is fastened with a union nut, the joint body and union nut are fewer parts There is an advantage that a good sealing function can be obtained while economically constituting a pipe joint with two points.

  However, in any of these conventional resin pipe joints, the union nut is turned and screwed in the axial direction to press-contact the edge portion against the tube. In some cases, so-called “spinning” occurs in which the tube rotates together with the union nut. When this rotation occurs, the tube is forcibly pulled and easily damaged, and the seal point due to the pressing of the edge portion shifts, resulting in a problem that the sealing performance is adversely affected.

In particular, when the resin pipe joint is formed of a resin material having a large expansion coefficient such as a fluororesin so as to handle a high temperature fluid of 100 ° C. or higher, those problems become more prominent. Therefore, there is still room for improvement with respect to ensuring the performance of the resin pipe joint having a good sealing property without causing the tube to rotate with the union nut.
Noto 3041899 Japanese Patent Laid-Open No. 7-27274 JP 2002-357294 A

  In view of the above circumstances, the object of the present invention is to devise the tube so that it does not rotate with the turning operation of the union nut, while being economical, consisting of the joint body and the union nut. Another object of the present invention is to provide a resin pipe joint capable of ensuring good sealing performance without causing accompanying rotation due to the joint structure.

The invention according to claim 1 is a synthetic resin joint main body 1 including an inner tube portion 4 that can be externally fitted by expanding the diameter of an end portion of the synthetic resin tube 3 and a male screw portion 5 in a resin pipe joint. ,as well as,
A diameter expansion change region in a nut main body 2A including a female screw portion 8 and a rotated operation portion 18 that can be screwed into the male screw portion 5, and a diameter increasing portion 3A that is externally fitted to the inner cylindrical portion 4 of the tube 3. 9 has a union nut 2 in which a pressing action cylinder 2B having a sealing pressing portion 10 that can act on the small diameter side portion 9 is connected and integrated so as to be relatively rotatable around the axis P of the joint body 1. ,
The nut main body 2A is rotated in a state where the tube 3 is externally fitted to the inner cylinder portion 4 to form the enlarged diameter portion 3A, and the female screw portion 8 is screwed into the male screw portion 5. The union nut 2 is configured to be pressed in the axial center P direction by the sealing pressing portion 10 by the small diameter side portion of the diameter expansion changing region 9 by the screwing of the union nut 2 in the axial center P direction. It is characterized by.

  According to a second aspect of the present invention, in the resin pipe joint according to the first aspect, the pressing action cylinder 2 </ b> B is provided with a retaining pressing portion 11 that can act on a large diameter side portion of the diameter expansion change region 9. The union nut 2 is configured to be configured such that the large-diameter side portion of the expanded diameter changing region 9 is pressed in the axial center P direction by the retaining pressing portion 11 by the screwing of the union nut 2. It is a feature.

According to a third aspect of the present invention, in the resin pipe joint according to the first or second aspect, the joint main body 1 has a radial gap m allowing the tube 3 to enter the inner cylindrical portion 4. A cover portion 6 to be covered is provided, and a cylindrical protrusion 13 is formed in the pressing action tube 2B so as to be able to enter between the enlarged diameter portion 3A and the cover portion 6 in the radial direction.
By the screwing of the union nut 2, the cylindrical protrusion 13 enters the radial gap m and is press-fitted between the enlarged diameter portion 3 </ b> A and the cover portion 6. It is a feature.

  According to a fourth aspect of the present invention, in the resin pipe joint according to the third aspect, the male screw portion 5 is also formed on the outer peripheral portion of the cover portion 6.

  According to a fifth aspect of the present invention, in the resin pipe joint according to any one of the first to fourth aspects, the outer peripheral portion of the pressing cylinder 2B is formed in both the bottom peripheral surface 15a and the axis P direction. An outer peripheral groove 15 having side peripheral walls 15B and 15C is formed, a ring portion 19 that fits into the outer peripheral groove 15 is formed in the nut main body 2A, and a shaft of the both peripheral walls 15B and 15C is formed. The outer peripheral wall 15C far from the joint body 1 in the center P direction has a diameter that allows the ring portion 19 to be forced into the outer peripheral groove 15 and has a smaller diameter toward the outer side in the axis P direction. It is formed in the outer peripheral wall for mounting | wearing which has the taper outer peripheral surface 20 attached.

  The invention according to claim 6 is the resin pipe joint according to any one of claims 1 to 5, wherein both the joint body 1 and the union nut 2 are made of a fluororesin.

  According to the first aspect of the present invention, as will be described in detail in the section of the embodiment, the seal portion is formed at the tip portion of the inner tube portion by tightening by turning the union nut, and the inner tube portion. The tube and the joint main body are satisfactorily sealed without entering the fluid between the first and the enlarged diameter portions. Then, the union nut turning operation with the sealing pressing part in contact with the diameter expansion change region of the tube may cause the tube to rotate with its strong pressure contact force, but the nut body constituting the union nut and The structure that can rotate relative to the pressing cylinder functions so that the tube does not rotate. As a result, while making the joint body and the union nut economical, it is possible to reduce the follow-up caused by the joint structure by devising the tube so that the turn of the union nut does not occur. It is possible to provide a resin pipe joint that can ensure good sealing performance without being generated.

  According to the second aspect of the present invention, the retaining pressing portion acts so as to press the large-diameter side portion of the expanded diameter changing region in the axial direction by screwing of the union nut. Thus, it is possible to provide a resin pipe joint in which the action of preventing movement in the direction of coming out of the inner cylinder portion is strengthened and the pull-out resistance is further improved.

  According to the invention of claim 3, the expanded diameter portion is restrained from the inside and outside in the radial direction by the inner cylindrical portion and the cylindrical projection, and is firmly held so that it cannot be displaced or expanded and deformed. A function in which movement in the direction of coming out of the inner cylinder portion in the axial direction is effectively restricted occurs. Therefore, it is possible to provide a resin pipe joint that can achieve both the pull-out resistance and the good sealing performance while being economical, consisting of the joint body and the union nut. In this case, when there is a pressing portion for retaining, a resin pipe joint is provided that has an enhanced action of preventing the diameter-expanded portion from being pulled out from the inner cylinder portion by cooperating with the pressing portion, thereby further improving the pull-out resistance. Can do.

  According to the invention of claim 4, since the insertion portion of the tube into the inner tube portion, that is, the expanded diameter portion and the male thread portion can be overlapped in the axial direction, the screw between the union nut and the joint main body can be achieved. It is possible to provide a resin pipe joint having an advantage that the axial length can be made compact while having a joint structure.

  According to the invention of claim 5, although described in detail in the section of the embodiment, the ring portion is pushed in the axial direction from the outer peripheral wall side, and is fitted into the outer peripheral groove by forced insertion through the tapered outer peripheral surface. A union nut in which the pressing cylinder and the nut body are connected and integrated can be obtained. That is, there is an advantage that the nut body and the pressing cylinder can be relatively rotated, but the parts are single, and the nut body and the pressing cylinder can be easily assembled.

  According to the invention of claim 6, since both the joint body and the union nut are formed of a fluorine-based resin having characteristics excellent in chemical resistance and heat resistance, even if the fluid is a chemical liquid or a chemical liquid, Or even if it is a high-temperature fluid, a joint structure part does not deform | transform and it becomes easy to leak, and favorable sealing property and drawing-out force can be maintained now. Note that the fluorine-based resin is preferable in that it is stable at high temperatures, excellent in water repellency, has a small coefficient of friction, has extremely high chemical resistance, and has high electrical insulation.

  Embodiments of a resin pipe joint according to the present invention will be described below with reference to the drawings. FIG. 1 is a cross-sectional view of a resin pipe joint according to Example 1, and FIG. 2 is an enlarged cross-sectional view of a main part of the resin pipe joint of FIG.

[Example 1]
As shown in FIGS. 1 and 2, the resin pipe joint A according to Example 1 includes a tube 3 made of a fluororesin (an example of a synthetic resin typified by PFA, PTFE, etc.), a fluid device such as a pump and a valve, A joint body 1 made of fluororesin (an example of a synthetic resin typified by PFA, PTFE, etc.) and a fluororesin (synthetic resin typified by PFA, PTFE, etc.) are connected to tubes of different diameters or the same diameter. An example) It is comprised by two parts with the union nut 2 made from. Each figure shows an assembled state in which the union nut 2 is tightened by a predetermined amount.

  As shown in FIGS. 1 and 2, the joint body 1 is expanded in diameter to the outer cylinder side 4 of the inner cylinder part 4 and the inner cylinder part 4 at one end where the end part of the tube 3 can be expanded and fitted. A cover cylinder portion 6 having a circumferential groove (an example of a “radial gap”) m extending in the axis P direction to allow the tube 3 end to enter, a male screw portion 5 such as a trapezoidal screw, and a shaft center It is formed in a cylindrical member provided with a cylindrical space-like fluid path 7 having P. The inner cylinder part 4 has a straight shape having a tip tapered cylinder part 4A for gradually expanding the diameter of the tube 3 and a straight cylinder part 4B formed on the large diameter side of the tip tapered cylinder part 4A. It is structured as a thing.

  In the circumferential groove m, the outer peripheral surface that is the inner peripheral surface of the diameter is the outer peripheral surface 4b of the straight barrel portion 4B, and the outer peripheral surface that is the outer peripheral surface of the diameter is the inner peripheral surface 6a of the cover tube portion 6. Thus, it is formed with a wide radial width. A joint flange 1A is formed at a position away from the inner peripheral surface 21 of the circumferential groove m in the axial center P direction by a predetermined length, and the outer peripheral surface of the end portion of the cover cylinder portion 6 from the substantially root portion of the joint flange 1A. A male screw portion 5 is formed over the entire area. The tip surface of the inner cylinder part 4 is formed with a reverse taper angle that is closer to the inner inner side (the inner side in the direction of the axis P) toward the inner side in the radial direction. The shape of the liquid reservoir peripheral portion 17 due to the inner peripheral surface of the tube 3 being expanded and displaced toward the enlarged diameter portion (flare portion) is defined as the inner peripheral side expanded shape, and the fluid is stored in the liquid peripheral portion. 17 is difficult to stay. The cut surface 16 is formed so that the maximum diameter thereof is a substantially intermediate value between the inner diameter and the outer diameter of the tube 3 in the natural state, but this is not particularly concerned.

  As shown in FIGS. 1 and 2, the union nut 2 is integrally formed by connecting a nut body 2A on the outer diameter side, a pressing action cylinder 2B on the inner diameter side, and these 2A and 2B so that they can rotate relative to each other around the axis P. And connecting means 2C. The nut body 2 </ b> A has a cylindrical shape including a female screw portion 8 that can be screwed into the male screw portion 5, a rotated operation portion 18 for gripping and turning with a finger, and an inward flange (an example of a ring portion) 19. It is formed as a member. The pivoted operation portion 18 is basically an outer peripheral surface, and the inward flange 19 is formed in a donut shape with a square cross section having an inner peripheral surface 19a, an inner peripheral surface 19b, and an outer peripheral surface 19c. .

  The pressing cylinder 2B is a sealing peripheral edge (an example of a “sealing pressing section”) that can act on the small diameter side portion of the diameter expansion change region 9 in the diameter expanding section 3A that is externally fitted to the inner cylinder section 4 of the tube 3. 10, a retaining peripheral edge (an example of a “preventing pressing portion”) 11 that can act on the large-diameter side portion of the diameter-enlargement changing region 9 in the diameter-enlarging portion 3 </ b> A, A cylindrical projection 13 that can enter the circumferential groove m in a state of being inserted between and a guide cylinder portion that encloses the tube 3 over a predetermined length in the direction of the axis P following the sealing circumferential edge 10. 14 and an outer peripheral groove 15 in which an inner peripheral end of the inward flange 19 can be loosely fitted.

  The outer peripheral groove 15 has a bottom peripheral surface 15a which is an outer peripheral surface, an inner outer peripheral wall 15B having an inner peripheral surface 15b, and an outer outer peripheral wall 15C having an outer peripheral surface 15c. The peripheral surfaces 15a to 15c correspond to the inner peripheral surface 19a, the inner peripheral surface 19b, and the outer peripheral surface 19c of the inward flange 19, respectively, and are relatively movable between the two. The outer peripheral wall 15C having the outer peripheral surface 15c has a tapered outer peripheral surface 20 that has an extremely small rising dimension in the radial direction from the bottom peripheral surface 15a and has a smaller diameter toward the outer side in the axis P direction. .

  Therefore, the inward flange 19 can be pushed in the direction of the axis P from the outer peripheral wall 15C side, and can be fitted into the outer peripheral groove 15 by forced insertion through the tapered outer peripheral surface 20 to form the connecting means 2C. is there. As a result, the nut main body 2A and the pressing cylinder 2B can be connected and integrated so as to be relatively rotatable, so that the union nut 2 as a single part can be brought into a state in advance before assembly as the resin pipe joint A. In this case, the nut body may be heated and expanded so that it can be more easily assembled to the pressing cylinder 2B.

  In other words, the outer peripheral groove 15 having the outer peripheral wall 15B and 15C formed in both the bottom peripheral surface 15a and the axial center P direction is formed on the outer peripheral portion of the pressing cylinder 2B. A mating inward flange 19 is formed on the nut body 2A, and the outer peripheral wall 15C far from the joint body 1 in the direction of the axis P of the outer peripheral walls 15B and 15C is connected to the outer peripheral groove 15 of the direction flange 19. It is formed on the outer peripheral wall for mounting having a tapered outer peripheral surface 20 having a diameter that allows forcible insertion and an inclination that becomes smaller toward the outer side in the axis P direction.

  The sealing peripheral edge 10 has an inner diameter substantially equal to the outer diameter of the tube 3, and the pressing surface 10 a is a side peripheral surface orthogonal to the axis P. The circumferential edge 11 for retaining is slightly larger in diameter than the outer peripheral surface 4b of the straight barrel portion 4B, which is the maximum diameter of the inner cylindrical portion 4, and the thickness of the enlarged diameter portion 3A is added. The diameter, that is, a value smaller than the inner diameter of the cylindrical protrusion 13 is set, but the point may be the large-diameter side portion of the diameter expansion change region 9. The pressing surface 11a of the retaining peripheral edge 11 is also a side peripheral surface orthogonal to the axis P.

  The cylindrical protrusion 13 is externally fitted to the enlarged straight portion 12 surrounded by the straight barrel portion 4B having a constant diameter in the enlarged diameter portion 3A and is fitted to the cover cylindrical portion 6 so as to be circumferentially-circulated m. It is a straight cylindrical part that enters. As shown in FIGS. 1 and 2, in the state assembled as a joint, it reaches almost the far side peripheral surface 21 of the circumferential groove m similarly to the enlarged diameter portion 3 </ b> A, and the enlarged diameter straight portion 12 and the cover cylinder portion 6. It is in a state of being press-fitted between. Accordingly, as a result, the enlarged diameter straight portion 12 is in a state of being press-fitted between the straight barrel portion 4B and the cylindrical protrusion 13.

  Next, in order to externally insert and insert the end of the tube 3 into the inner cylinder portion 4, the tube 3 is forcibly pushed in at room temperature to expand the diameter, or it is easily heated and expanded using a heat source. Then, the tube end 3t is moved as shown in FIG. 1 by pushing it in, or by enlarging the tube end in advance using a diameter expander (not shown) and then pushing it into the inner cylinder part 4. It is inserted to the inner depth to the extent that it almost reaches the inner circumferential surface 21 of the circumferential groove m. As shown in FIGS. 1 and 2, the enlarged-diameter portion 3A that is externally fitted to the inner cylinder portion 4 includes an enlarged-diameter changing region 9 that is fitted on the outer peripheral surface 4a of the cylindrical portion 4A. It consists of the diameter-expanded straight part 12 fitted on the outer peripheral surface 4b of the barrel part 4B.

  As shown in FIGS. 1 and 2, a union nut is obtained by screwing the female threaded portion 8 with the male threaded portion 5 in a state where the tube 3 is externally fitted to the inner cylindrical portion 4 and rotating the nut body 2A. First, the cylindrical protrusion 13 is forcibly inserted between the enlarged diameter straight portion 12 and the cover cylindrical portion 6 by the screwing of the joint body 1 in the direction of the axis P by the tightening of No. 2, and then the enlarged diameter changing region. 9 is pressed in the axial center P direction by the retaining peripheral edge 11, and the small diameter side portion of the expanded diameter change region 9 is used for sealing. The peripheral edge 10 is pressed in the direction of the axis P. Note that the diameter of the fluid transfer path 3W of the tube 3 and the diameter of the fluid path 7 are set to be the same diameter in order to obtain a smooth fluid flow, but may be different from each other.

  In this case, the radially enlarged straight portion 12 and the cylindrical protrusion 13 that are overlapped in the radial direction are pressed into the circumferential groove m, and there is no gap between the inside and outside of the enlarged straight portion 12, and the straight barrel portion 4B and the cylinder It is in the state where it is press-clamped between the protrusions 13. At this time, the union nut 2 is formed in a cylindrical shape in the circumferential groove m because the pressing cylinder 2B and the nut body 2A can be rotated relative to each other by the fitting of the outer circumferential groove 15 and the inward flange 19 by the connecting means 2C. The pressing cylinder 2B that receives a large resistance to the rotational movement around the axis P due to the press-fitting of the protrusion 13 does not rotate around the axis P by rotating relative to the nut body 2A. Become. That is, it is possible to rotate only the nut main body 2A without rotating the pressing cylinder 2B.

  Thereby, the inconvenience that the diameter-enlarging straight portion 12, that is, the diameter-enlarging portion 3A, rotates together with the cylindrical protrusion 13 along with the turning operation of the union nut 2 can be prevented. If the expanded diameter portion 3A is rotated, the tube 3 is apt to be twisted, thereby causing problems such as unpredictability of the retaining function and the sealing function. Can be solved by using only one component of the union nut 2 having a relatively rotatable structure.

  Moreover, in Example 1, the diameter-expansion change area | region 9 of the tube 3 is formed as a part which the front-end | tip narrows and covers 4 A of cylinder parts. The diameter expansion change region 9 is a state of a taper tube that gradually expands, and the sealing peripheral edge 10 and the retaining peripheral edge 11 are in a positional relationship apart from each other in the axis P direction, but the tip tapered tube As the angle of the outer peripheral surface 4a of the portion 4A with respect to the axial center P becomes steeper, the distance in the axial center P direction between the sealing peripheral edge 10 and the retaining peripheral edge 11 becomes closer. Further, the sealing peripheral edge 10 and the inner cylinder portion 4 are slightly separated from each other in the direction of the axis P (see FIG. 2 and the like). However, if the angle of the outer peripheral surface 4a becomes steep, the distance is increased. If it becomes loose, the separation distance is reduced.

  As shown in FIGS. 1 and 2, in a predetermined assembled state of the resin pipe joint A, the sealing peripheral edge 10 has the small diameter side end portion of the diameter expansion change region 9 of the tube 3 in the axis P direction. Since the pressing is performed, the small diameter side end of the outer peripheral surface 4a of the diameter expansion change region 9 and the inner peripheral surface of the tube 3 in contact with the portion are strongly pressed to form the seal portion S. The tube 3 and the joint main body 1 are well sealed by the seal portion S at the tip of the inner tube portion 4 without any fluid such as cleaning liquid or chemical solution entering between the inner tube portion 4 and the enlarged diameter portion 3A. Yes.

  And the diameter-enlarging straight part 12 of the diameter-enlarging part 3A that is press-fitted to the inner cylinder part 4 is sandwiched between the outer peripheral surface 4b of the straight cylinder part 4B and the cylindrical projection 13, and is first expanded and deformed. Since the holding peripheral edge 11 is positioned so as to substantially bite into the enlarged diameter straight portion 12, the enlarged diameter portion 3 </ b> A extends from the inner cylinder portion 4 in the direction of the axis P. The retaining means N that firmly restricts the movement in the direction of withdrawal is configured, thereby realizing an excellent pull-out resistance. That is, when the union nut 2 is tightened, the retaining peripheral edge 11 presses the enlarged diameter straight portion 12 in the axial direction so as to prevent the tube 3 from being pulled out. This is because the pull-out force due to the cooperation with the retaining peripheral edge 11 is increased so as to prevent the outer shell 12 from escaping so as to swell outward in the diameter.

  As a result, the flare-type resin pipe joint A composed of the joint body 1 and the union nut 2 can be easily assembled by a tightening operation in a state where the tube is mounted on the inner cylinder portion, and the assembly performance is excellent. At the same time, it is realized as an improved one that can achieve both excellent sealing performance by the seal portion S and excellent pull-out resistance by the retaining means N.

[Another Example]
The resin pipe joint A according to the present invention may have a configuration using the union nut 2 that does not have either the retaining pressing portion 11 or the cylindrical protrusion 13 or both. For example, even when the union nut 2 is rotated in a state in which the seal pressing portion 10 such as a seal peripheral edge is in contact with the tube 3, the tube 3 may be rotated by the strong pressure contact force. And a structure capable of rotating relative to the pressing cylinder 2B are effective.

  The connecting means 2C may have a structure in which a ring portion formed in the pressing cylinder 2B is fitted in a circumferential groove formed in the nut body 2A. In this case, in the structure in which the pressing cylinder 2B presses the tube 3 by pressing the nut body 2A, the connecting means 2C of the first embodiment is more advantageous in terms of strength and compactness in the radial direction and the axial direction. is there. In addition, the sealing pressing portion 10 and the retaining pressing portion 11 include an intermittent circumferential edge divided into a plurality in the circumferential direction, a cross-sectional shape with an angle of 80 degrees or 100 degrees, etc. An angle other than 90 degrees (right angle) shown may be used.

  As the synthetic resin, various resins such as PEEK (polyetheretherketone) and PP (polypropylene) can be used in addition to the fluororesin. Further, as the fluororesin, various types such as PTFE, PFA, PVDF, ETFE and the like are possible.

Sectional drawing which shows the structure of the resin pipe joint by Example 1 FIG. 1 is an enlarged sectional view showing the main part of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Joint main body 2 Union nut 2A Nut main body 2B Press action cylinder 3 Tube 3A Expanded diameter part 4 Inner cylinder part 5 Male thread part 6 Cover part 8 Female thread part 9 Expanded diameter change area 10 Sealing pressure part 11 Depressing pressure part 13 Tube Protrusion 15 Outer peripheral groove 15B Inner peripheral wall 15C Outer peripheral wall 15a Bottom peripheral surface 18 Turned operation portion 19 Ring portion 20 Taper outer peripheral surface P Axis center m Radial gap

Claims (6)

Synthetic resin joint body provided with an inner cylinder portion that can be fitted to the outside by expanding the end of the synthetic resin tube, and a male screw portion, and
Acting on a small diameter side portion of a diameter increasing change region in a nut main body having a female screw portion that can be screwed to the male screw portion and a rotated operation portion, and a diameter increasing portion that is externally fitted to the inner tube portion of the tube A pressing cylinder having a pressing portion for sealing, and a union nut that is connected and integrated so as to be relatively rotatable around the axis of the joint body,
The shaft of the union nut in which the female threaded portion is screwed to the male threaded portion by rotating the nut body in a state where the tube is fitted on the inner cylindrical portion to form the enlarged diameter portion. A resin pipe joint configured such that a small diameter side portion of the diameter expansion change region is pressed in the axial direction by the sealing pressing portion by screwing in a central direction.   The pressing action cylinder is provided with a retaining pressing portion that can act on the large-diameter side portion of the diameter expansion change region, and the large diameter side portion of the diameter expansion change region by the screwing of the union nut. The resin pipe joint according to claim 1, wherein the resin pipe joint is configured to be pressed in the axial direction by the retaining pressing portion. The joint main body is provided with a cover portion that covers the inner cylinder portion with a radial gap that allows the tube to enter, and the enlarged diameter portion and the cover portion are arranged in the radial direction on the pressing action cylinder. A cylindrical projection that can enter between and is formed,
3. The structure according to claim 1, wherein the cylindrical protrusion enters the radial gap and is press-fitted between the enlarged diameter portion and the cover portion by the screwing of the union nut. Resin pipe fittings.   The resin pipe joint according to claim 3, wherein the male screw portion is also formed on an outer peripheral portion of the cover portion.   An outer peripheral groove having a bottom peripheral surface and a side peripheral wall formed in both axial directions is formed on the outer peripheral portion of the pressing action cylinder, and a ring portion that fits into the outer peripheral groove is the nut body. The outer peripheral wall on the side farther from the joint main body in the axial direction of the both side peripheral walls has a diameter that can be forced into the outer peripheral groove of the ring portion, and is outer in the axial direction. The resin pipe joint according to any one of claims 1 to 4, wherein the resin pipe joint is formed on a mounting outer peripheral wall having a tapered outer peripheral surface having an inclination with a smaller diameter.   The resin pipe joint according to any one of claims 1 to 5, wherein the joint body and the union nut are both made of a fluororesin.

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