JP2010223347A - Resin pipe joint - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a resin pipe joint improved to be excellent in assembly work efficiency and handling properties to confirm that tightening of a union nut is ended or almost ended even in a noisy work site. <P>SOLUTION: In the resin pipe joint, the union nut 2 advances by screwing a male screw 5 into a female screw 8 in a state that a tube 3 is externally fitted to an inner cylinder 4 to form a diameter-enlarged part 3A, and a diameter-enlarged change region 9 is pressed by a pressing part 10 for sealing. A ring body 18 is externally fitted to a joint body 1 rotatably between an outer peripheral flange 1A and a union nut end surface 2a in an axis P direction, a co-rotation means D co-rotating the ring body 18 by the rotated union nut 2 is provided, and a tightening end recognition means C is provided so that the ring body 18 is started to be co-rotated when the union nut 2 is in the advancing end state that the pressing part 10 for sealing presses the diameter-enlarged change region 9 and a seal part S is formed. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention is also suitable for piping of high-purity liquid and ultrapure water handled in manufacturing processes in various technical fields such as semiconductor manufacturing, medical / pharmaceutical manufacturing, food processing, chemical industry, etc., and includes pumps, valves, filters, etc. The present invention relates to a resin pipe joint used as a connecting means for a tube which is a fluid device 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 fitting cylinder (5) of the joint body (4), or as shown in FIG. Is expanded to fit into the fitting cylinder (5). Then, the union nut (6) fitted in the tube in advance is screwed into the joint body, and tightened to forcibly move in the axial direction of the joint body (4), thereby expanding the tube (1). The diameter root portion (2a) is strongly pressed in the axial direction by the edge portion (6a) to seal between the tube (1) and the fitting tube (5).

  A resin pipe joint disclosed in FIGS. 8 and 9 of Patent Document 2 is also known as the same structure as described above. Further, as disclosed in FIG. 5 of Patent Document 2 and Patent Document 3, a tube end that is externally expanded to the inner ring is internally fitted in a fitting cylinder of the joint body, and the tube is tightened by a union nut. There is also a resin pipe joint having a structure in which a diameter-enlarged portion to the inner ring is pressed and sealed. In any case, the tube end is expanded (flared) and sealed with a union nut. In the former structure in which the end of the tube is fitted outside the fitting cylinder part and is fastened with a nut, there is a merit that a pipe joint can be economically configured with two parts of a joint body and a union nut. With the structure, it is possible to reliably avoid leakage, obtain stable performance, and have excellent reliability.

  By the way, in actual construction of resin pipe joints having various excellent merits as described above, there is a chronic improvement item that it is difficult to understand the end point of union nut tightening. Originally, in the joint made of resin, due to the characteristics of the material, the tightening torque gradually increases with respect to the union nut turning operation, so the feeling of closing due to the sudden increase in the tightening torque like a metal material is poor, It is difficult to understand the end of tightening sensuously. Insufficient tightening may cause leakage, and excessive tightening may damage the joint. Since it is made of resin, these disadvantages are likely to occur. Therefore, it is necessary to correctly complete the tightening of the union nut.

Therefore, in Patent Document 3, a projecting piece (15) projecting in the axial direction in a cantilevered state on the joint body (1), and a protrusion formed on the end of the union nut (2) in the axial direction ( When the union nut (2) is about to end tightening, it comes into close contact with each other in the circumferential direction and comes into contact with it. A technique is disclosed that makes it possible to know that the person is approaching. That is, it is a sound generating means that informs the operator of the tightening end state by sound.
Noto 3041899 gazette Japanese Patent Laid-Open No. 7-27274 Japanese Patent Laid-Open No. 11-230463

  Even if the pipe joint portion is not visible, the sound generating means enables confirmation by the sound recognition of the tightening end state by the union nut operation, and a certain effect can be obtained. However, the actual piping work site is rarely in a quiet situation, and it is in a certain level of noise conditions, such as working in a factory that is in operation or other work and construction work being done together Will be done. Therefore, it is often impossible for the operator to hear the sound of the resin protruding piece, and there is still room for further improvement as means for notifying the end of tightening of the union nut, that is, a means for recognizing the end of tightening. It was a thing.

  In view of the above circumstances, the object of the present invention is to make it possible to confirm that the union nut has been tightened or is in a state close to it even in a work site under noise conditions, and to improve workability and handling. It is in providing a resin pipe joint that is improved to be superior.

The invention according to claim 1 is a synthetic resin joint body 1 comprising a fitting tube 4 that can be fitted and mounted by expanding the diameter of an end of the synthetic resin tube 3, and a male screw 5, and
A union nut 2 made of a synthetic resin including a female screw 8 that can be screwed into the male screw 5 and a sealing pressing portion 10 that can act on a diameter expansion change region 9 in the diameter expansion portion 3A of the tube 3;
The union nut 2 is screwed in the direction of the axis P of the joint body 1 by screwing the female screw 8 with the male screw 5 in a state where the tube 3 is fitted and attached to the fitting cylinder 4, In the resin pipe joint configured such that the diameter-enlarged change region 9 is pressed in the axial center P direction by the seal pressing portion 10 to form the seal portion S.
The joint body 1 is rotated about the axis P between the outer peripheral flange 1A formed on the joint body 1 and the tip 2a of the union nut 2 on the screwing side of the union nut 2 to the joint body 1 in the axis P direction. The movable ring body 18 is externally fitted, and a follow-up means E is provided for rotating the ring body 18 by the union nut 2 to be rotated. When the union nut 2 in which the seal portion S is formed by pressing the diameter-enlargement changing region 9 is in a state where the union of the union 2 is finished or just before the union, the ring body 18 starts to be rotated by the union nut 2. It is characterized in that a tightening end recognizing means C is provided.

  According to a second aspect of the present invention, there is provided the resin pipe joint according to the first aspect, wherein the follow-up means E is formed on the tip 2a of the union nut 2 so as to project toward the ring body in the direction of the axis P. And an engagement protrusion 19 that is formed on the ring body 18 so as to protrude toward the union nut in the direction of the axis P, and when the screwing is completed or just before that, the engagement protrusion 20 is The projection 19 is set to start pressing.

  According to a third aspect of the present invention, in the resin pipe joint according to the first or second aspect, the union nut 2 and the union of the ring body 18 from the screwing end state when the ring body 18 starts to be rotated by the union nut 2. The union nut 2 can be operated by turning a predetermined amount in the tightening direction until the ring body 18 is sandwiched between the outer peripheral flange 1A and a tightening limit state where further screwing is prevented is reached. The fastening means E is provided.

  According to a fourth aspect of the present invention, in the resin pipe joint according to the third aspect, the ring body 18 has a first ring portion 18a along the outer peripheral flange 1A and a union nut side having the engaged protrusion 19. The second ring portion 18b and a connecting portion 18c that connects the first ring portion 18a and the second ring portion 18b in a state of being displaced in the circumferential direction with respect to the engaged protrusion 19, and The fastening means E is deformed in the direction of the axis P in the first ring portion 18a other than the connecting portion 18c, and the ring body 18 is connected to the outer peripheral flange 1A and the union nut 2 in the connecting portion 18c. The union nut 2 can be turned until it reaches the tightening limit state sandwiched between them.

  According to a fifth aspect of the present invention, in the resin pipe joint according to the fourth aspect, each of the engaging protrusion 20, the engaged protrusion 19, and the connecting portion 18c is provided at four locations at equal intervals in the circumferential direction. It is characterized by being provided.

  The invention according to claim 6 is the resin pipe joint according to any one of claims 1 to 5, wherein 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, when the tightening of the union nut is advanced by the function of the tightening end recognition means, the outer peripheral flange of the joint body and the union nut tip A situation appears in which the ring body interposed between them is rotated around the union nut. Therefore, by visually confirming that the ring body has started to rotate, it can be recognized that the union nut has been tightened. As a result, the resin pipe joint is improved so that it can be confirmed that the union nut has been tightened or is close to it even in a work site under noisy conditions, and the assembly workability and handling are excellent. Can be provided.

  According to the second aspect of the present invention, the engagement protrusion starts to push the engagement protrusion and the ring body is rotated by the rotation means comprising the engagement protrusion at the tip of the union nut and the engagement protrusion of the ring body. By visually checking the situation, it is possible to recognize that the screwing end state or the immediately preceding state is reached. That is, the above-described effect of the invention according to claim 1 is rational and economical by means of a tightening end recognizing means having a simple rotating follower means for providing the engaging protrusion of the union nut and the engaged protrusion of the ring body. There are benefits to be gained.

  According to the invention of claim 3, since the union nut can be tightened by a predetermined amount from the tightening end state by the tightening means, it is possible to ensure the prevention of loosening due to changes over time, and thus the prevention of leakage, It is possible to provide a resin pipe joint that exhibits a sealing function effectively over a long period of time and is excellent in reliability.

  According to the invention of claim 4, the first ring portion, the second ring portion, and the connecting portion constitute a ring body, and the engaged protrusion can be reduced and moved in the axial direction, thereby tightening. A tightening means is provided that enables the union nut to be tightened by a predetermined amount from the attachment end state. Therefore, by improving the component (= ring body) of the tightening end recognizing means, the practicality and handleability can be improved without increasing the size such as adding the number of parts or adding space. There exists an advantage by which the said effect by invention is acquired. In this case, as in claim 5, if each of the engaging protrusions, the engaged protrusions, and the connecting portion is provided at four positions at equal intervals in the circumferential direction, the structure has strength and functions reliably. A practical resin pipe joint can be obtained.

  According to the invention of claim 6, the joint body and the union nut are formed of a fluorine-based resin excellent in chemical resistance and heat resistance, and the fluid is a chemical liquid, a chemical liquid, or a high-temperature fluid. Even if it exists, a joint structure part does not deform | transform and does not become easy to leak, but favorable sealing property and drawing-out resistance can be maintained now. A 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. 1 is a cross-sectional view showing the structure of the resin pipe joint of Example 1, FIG. 2 is a plan view of the resin pipe joint of FIG. 1, FIG. 3 is a front view showing the ring body, and FIG. FIG. 5 is a plan view of the resin pipe joint showing the tightening limit state after retightening.

[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 represented by PFA, PTFE, etc.), a fluid device such as a pump and a valve, A joint body 1 made of fluororesin (an example of synthetic resin represented by PFA, PTFE, etc.) and a fluororesin (synthesis represented by PFA, PTFE, etc.) are connected to tubes of different diameters or the same diameter. An example of resin) It is composed of three parts including a union nut 2 made of a ring and a ring body 18. FIG. 1 shows a tightening end state (assembled state) in which the union nut 2 is tightened by a predetermined amount.

  As shown in FIGS. 1 and 2, the joint main body 1 includes an inner cylinder 4 (one example of a fitting cylinder) 4 that can be externally fitted by expanding the diameter of the end of the tube 3, and an inner depth of the inner cylinder 4. A cover cylinder portion 6 having a circumferential groove m extending in the direction of the axis P in order to allow entry of the tip of the tube 3 whose diameter is expanded on the outer peripheral side of the side portion, a male screw 5 made of a trapezoidal screw, and the axis P It is formed in the cylindrical member provided with the cylindrical fluid-like fluid path 7 having the outer peripheral flange 1A and the like. The inner cylinder 4 has a tapered straight shape having a tapered tip portion 4A for gradually expanding the diameter of the tube 3 and a straight barrel portion 4B formed on the large diameter side of the tapered tip portion 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 cylindrical portion 6. . An outer peripheral 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 tube portion 6 from the substantially root portion of the outer peripheral flange 1A. A male screw 5 is formed over the entire area. The tip surface of the inner cylinder 4 is provided with a reverse taper angle closer to the inner back side (back side in the direction of the axis P) toward the inner side in the radial direction, that is, a cut surface 16 having a larger diameter toward the tip is formed. The shape of the liquid pool peripheral portion 17 resulting from the displacement of the inner peripheral surface of the tube 3 toward the enlarged diameter portion (flare portion) is defined as the inner peripheral side expanded shape, and the fluid is stored in the liquid pool peripheral portion 17. It is hard to be stagnant.

  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. Further, on the side opposite to the male screw 5 in the axial center P direction of the flange 1A, an operation hexagon nut portion 23 having a constant width in the axial center P direction, and a subsequent pipe portion (connecting portion) 25 (FIG. 2). 4 and 5).

  As shown in FIGS. 1 and 2, the joint body 1 is provided with a mounting outer peripheral surface 1 c having a diameter equal to or larger than the mountain diameter of the male screw 5 following the male screw side surface 1 a of the outer peripheral flange 1 </ b> A. Yes. This is a configuration for mounting a ring body 18 (described later) so that it can be pivotally moved. The ring body 18 is sandwiched between the union nut 2 and the outer peripheral flange 1A, so that the ring is unionized by the union nut 2. A follow-up means D (described later) for rotating the body 18 is configured.

  As shown in FIGS. 1 and 2, the union nut 2 includes a female screw 8 that can be screwed into the male screw 5, and a small-diameter side of the enlarged-diameter changing region 9 in the enlarged-diameter portion 3 </ b> A that is externally fitted to the inner cylinder 4 of the tube 3. A peripheral edge for sealing (an example of a pressing portion for sealing) 10 that can act on the end portion, a circumferential edge 11 for retaining that can act on the large-diameter side end portion of the diameter expansion change region 9, and a diameter in the expanded diameter portion 3A The presser inner peripheral portion 13 that can be externally fitted to the diameter-enlarging straight portion 12 that is surrounded by a certain straight barrel portion 4B, and the tube 3 is placed over a predetermined length in the axis P direction following the sealing peripheral edge 10. And a guide cylinder portion 14 that surrounds the guide cylinder portion 14. In addition, 2A is the outer peripheral surface to which the anti-slip process was given, 2b is a nut part.

  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 diameter of the circumferential edge 11 for retaining is larger than that of the outer peripheral surface 4b of the straight barrel portion 4B whose inner peripheral surface is the maximum diameter of the inner tube 4, and the diameter obtained by adding the wall thickness of the tube 3 In other words, it is set to a value smaller than the diameter of the presser inner peripheral portion 13, but it may not be (for example, a smaller diameter than the outer peripheral surface 4 b), and acts on the larger diameter side portion of the diameter expansion change region 9. It ’s fine. The pressing surface 11a of the retaining peripheral edge 11 is also a side peripheral surface orthogonal to the axis P.

  The presser inner peripheral portion 13 has no radial clearance between the presser inner peripheral portion 13 and the enlarged diameter straight portion 12 so that the enlarged diameter portion 3A is not rotated by tightening of the union nut 2. The retaining means N is configured to be set to a value that is press-fitted (press-fit externally fitted). This is because 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 to prevent the portion 12 from escaping so as to swell outward in the radial direction, and to increase the pull-out force by cooperating with the peripheral edge 11 for retaining.

  As shown in FIGS. 1 and 2, an engagement protrusion for rotating the ring body 18 (described later) is provided on the female thread side end surface 2 a which is the tip of the union nut 2 on the joint body of the union nut 2. 20 is formed. The engagement protrusions 20 have a substantially rectangular shape in a plan view and have a certain size in the radial direction, and are integrally formed at a total of four locations for every 90 degree equal angle around the axis P.

  As shown in FIG. 1 to FIG. 3, flexibility is provided between the end surface 2 a on the female screw side, which is the tip of the union nut 2 on the joint body of the union nut 2, and the outer peripheral flange 1 </ b> A in the axial center P direction. A ring body 18 having a material (synthetic resin such as fluororesin, metal such as spring steel, rubber, etc.) is interposed. The ring body 18 to be mounted on the mounting outer peripheral surface 1c of the joint body 1 includes a first ring portion 18a along the outer peripheral flange 1A, specifically, the male thread side surface 1a, and a second ring on the union nut side having an engaged protrusion 19. It is comprised as a gauge ring which has the part 18b and the connection part 18c which connects the 1st ring part 18a and the 2nd ring part 18b in the state which is displaced from the to-be-engaged protrusion 19 in the circumferential direction. The diameter of the ring body 18 is set to be the same as the diameter of the outer peripheral surface 1b of the outer peripheral flange 1A and the outer diameter of the union nut 2, but may be other than that.

  The second ring portion 18b has a substantially rectangular engaged projection 19 having a slight width in the circumferential direction and projecting toward the union nut in the direction of the axis P. Each is integrally formed at a total of four locations. Then, the connecting portions 18c having a slightly wider circumferential width than the engaged protrusions 19 are 4 in total at every 90 degree equal angle around the axis P in a state of being displaced by 45 degrees with respect to the engaged protrusion 19 and the axis P. The place is formed. The first ring portion 18a having the same diameter as that of the outer peripheral flange 1A and the second ring portion 18b having the same diameter as that of the union nut 2 have the same diameter. In other words, the ring body 18 is externally fitted to the mounting outer peripheral surface 1c of the joint body 1 between the outer peripheral flange 1A and the end surface 2a of the union nut 2 so as to be rotatable about the axis P. Yes.

  Next, in order to externally insert the end of the tube 3 into the inner cylinder 4, the tube 3 is forcibly pushed in at room temperature to increase the diameter, or it is warmed using a heat source so as to be easily deformed by expansion. The tube end 3t is formed as a cover tube as shown in FIG. 1 by pushing it into the inner tube 4 after expanding the tube end in advance using a diameter expander (not shown). Insert until the end wall 15 of the portion 6 is located inward. The diameter-enlarged portion 3A that is externally fitted to the inner cylinder 4 is fitted to the diameter-enlarged region 9 that is externally fitted to the outer peripheral surface 4a of the cylindrical portion 4A that is tapered at the tip, and the outer peripheral surface 4b of the straight barrel portion 4B. The enlarged diameter straight portion 12 is formed.

  That is, as shown in FIG. 1, in the axial center P direction of the joint body 1 by tightening the union nut 2 by screwing the female screw 8 with the male screw 5 in a state where the tube 3 is externally fitted to the inner cylinder 4. As a result of the screwing, the presser inner peripheral portion 13 is externally fitted to the enlarged diameter straight portion 12, and a portion having a larger diameter than the diameter of the inner cylinder 4 in the larger diameter side portion of the enlarged diameter changing region 9 is used for retaining. The peripheral edge 11 is pressed in the direction of the axis P, and the small diameter side portion of the diameter expansion change region 9 is set to be pressed in the direction of the axis P by the sealing peripheral edge 10. 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, as described above, there is no gap in the radial direction between the presser inner peripheral portion 13 and the enlarged diameter straight portion 12, and the enlarged diameter straight portion 12 is provided between the straight barrel portion 4B and the presser inner peripheral portion 13. It is in the state where it is clamped. 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 tip of the inner cylinder 4 are slightly separated from each other in the direction of the axis P, but if the angle of the outer peripheral surface 4a becomes steep, the separation distance is enlarged, and if it becomes loose, the separation distance. Is reduced.

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

  The diameter-enlarging straight part 12 of the diameter-enlarging part 3A that is press-fitted to the inner cylinder 4 is surrounded by the outer peripheral surface 4b of the straight cylinder part 4B and the presser inner peripheral part 13, and is first expanded and deformed. The retaining peripheral edge 11 is positioned so as to substantially bite into the enlarged diameter straight portion 12. This resists the pulling force acting on the enlarged diameter portion 3A due to the catch of the retaining peripheral edge 11 that pushes the large diameter side end portion of the enlarged diameter change region 9 so as to substantially bite into the enlarged diameter straight portion 12. In addition, the diameter-enlarged straight portion 12 can be expanded and deformed in the radial direction by the pulling force with the retaining peripheral edge 11 as a starting point. It also comes to be.

  If the diameter-enlarged portion 3A is displaced in the axial center P direction even a little, the seal point in the seal portion S may be shifted and the seal function may be uncertain, but this is prevented in advance. Accordingly, the retaining means N is configured in which the movement of the diameter-enlarged portion 3A in the direction of coming out of the inner cylinder 4 in the direction of the axis P is firmly restricted, thereby realizing an excellent pull-out resistance. 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 nut operation in a state where the tube is attached to the inner cylinder, and has excellent assemblability. It has been realized as an improved product that can achieve both excellent sealing performance by the seal portion S and excellent pull-out resistance by the retaining means N.

  In addition, after the pressing of the large-diameter side portion of the enlarged-diameter changing region 9 by the retaining peripheral edge 11 is started, the pressing of the small-diameter side portion of the enlarged-diameter changing region 9 by the sealing peripheral edge 10 is started. Depending on the setting, that is, the pressing time difference means, there are the following operations and effects. That is, when the union nut 2 is turned and tightened (screwed), the retaining peripheral edge 11 is first moved to the diameter expansion region 9 (specifically, the large diameter side portion of the diameter expansion region 9). At that time, the peripheral edge 10 for sealing has not yet reached the diameter expansion change region 9. As a result, only the retaining peripheral edge 11 pushes the large-diameter side portion of the expanded diameter change region 9, more specifically, the portion having a larger diameter than the straight barrel portion 4 </ b> B in the axial center P direction. The tightening operation causes an action to push the enlarged diameter straight portion 12 further into the inner side of the inner cylinder 4. The above describes the state in which the pressing of the small diameter side portion of the enlarged diameter change region 9 by the sealing peripheral edge 10 is started after the pressing of the large diameter side portion 9 of the enlarged diameter changing region 9 by the retaining edge 11 is started. However, the present invention is not limited to such a state, and a structure in which the retaining peripheral edge 11 and the sealing peripheral edge 10 simultaneously abut against the tube 3 may be employed, and in this case, the same action occurs.

  The diameter-enlarging straight portion 12 that is press-fitted and fitted to the straight barrel portion 4B is also pressed against the inner circumference portion 13 of the presser, but when the pressure-contact force is relatively weak, the diameter-enlarging portion 3A is displaced to move the inner cylinder 4 In order to insert the tube into the joint body 1 more reliably, the expanded diameter straight portion 12 pushed in the direction of the axis P is moved in the direction of the axis P. Due to the difficulty, it is possible to obtain a favorable effect that the pressure contact force is further increased and the action of being firmly clamped is generated in an attempt to expand in the radial direction. When the pressure contact force is relatively strong, the diameter-enlarging straight portion 12 pushed in the direction of the axis P is not able to move in the direction of the axis P first, thereby causing a strong action to expand in the radial direction. The effect that the diameter-expanded straight portion 12 is held more firmly with the presser inner peripheral portion 13 is obtained.

  That is, in any case, when the sealing peripheral edge 10 is not pierced into the enlarged diameter portion 3A, the retaining peripheral edge 11 pushes the enlarged diameter portion 3A in the direction of the axis P, thereby causing the straight barrel portion 4B. The press-holding force of the enlarged diameter straight portion 12 by the presser inner peripheral portion 13 is enhanced. For example, the portion that is pressed by the retaining peripheral edge 11 in the enlarged diameter portion 3A flows to the outside of the diameter and the corner space formed by the pressing surface 11a and the presser inner peripheral portion 13 is buried. As described above, the pressing time difference means has an effect of further improving both the pressure-contact holding force of the tube 3 with respect to the inner cylinder 4 and the pull-out resistance.

  Further, as shown in FIG. 1, the tube 3 is correctly formed by the circumferential groove m formed by the inner back side of the inner tube 4 and the cover tube portion 6 and the union nut 2 formed by a fluororesin that can be seen through. The indicator means B that can visually check whether or not it is inserted into the inner cylinder 4 may be configured. That is, the diameter-enlarged portion 3 </ b> A is visible and the diameter-enlarged end portion is visually observed on a line passing through the valley-shaped inner circumferential surface 22 until reaching the female screw 8 on the inner inner side of the presser inner circumferential portion 13. This is because it can be determined that the tube 3 is correctly fitted to the inner cylinder 4 if 3t is in a normal state invisible. If the poorly inserted state where the enlarged diameter portion 3A can be seen and the enlarged diameter end portion 3t can be seen, or the insufficiently inserted state where the enlarged diameter portion 3A itself cannot be seen, the insertion of the tube 3 has still reached the specified amount. In this case, an operation of further pushing the tube 3 is performed until the normal state can be visually confirmed.

  In the indicator means B, the union nut 2 is formed using a transparent or translucent (milky white or the like) fluororesin, and an object inside thereof can be visually confirmed. In particular, it is enlarged by seeing through only the portion where the thickness of the union nut 2 is small by visual observation on the inner back side of the presser inner peripheral portion 13 and through the valley-shaped inner peripheral surface 22 until reaching the female screw 8. The diameter portion 3A is relatively easily visible. On the other hand, the visibility of the enlarged diameter portion 3A is inferior at the part of the presser inner peripheral part 13 which is thicker than the part of the valley-shaped inner peripheral surface 22, and is difficult to see.

  And since the union nut 2 and the cover cylinder part 6 have overlapped in the part of the circumferential groove m in which the edge part of the tube 3 can enter, even if the joint main body 1 can also be seen through, thickness is a valley-shaped inner peripheral surface. In addition to being thicker than the portion 22, a change in the refractive index at the boundary surface due to the overlap of the male screw 5 and the female screw 8 is also added, so that it is impossible to visually recognize where the enlarged diameter end 3 t is located. In addition, when the joint body 1 is not transparent such as being colored, it is needless to say that the enlarged diameter portion 3A or the enlarged diameter end portion 3t is seen on the inner and inner side of the end wall 15 of the cover cylinder portion 6. I can't.

  Therefore, the union nut 2 was tightened by the function of the indicator means B whether or not a normal state in which the enlarged diameter portion 3A can be seen from the valley-shaped inner peripheral surface 22 and the enlarged diameter end portion 3t cannot be seen. A resin pipe joint A that can be visually confirmed in a later assembled state and that is convenient and excellent in usability can be provided.

  Further, the presence of the circumferential groove m and the cover cylinder portion 6 for constituting the indicator means B also provides an effect of functioning as an indicator when the tube 3 is inserted into the inner cylinder 4. That is, it can be confirmed whether or not the amount of insertion into the inner cylinder 4 by flaring the tube 3 is a predetermined amount. That is, it is sufficient that the end 3t as the enlarged diameter portion 3A inserted into the inner cylinder 4 is deeper than the end wall 15, and as a means for visually judging whether the tube 3 is assembled to the inner cylinder 4 or not. There is an advantage to function.

  Next, the tightening end recognition means C will be described. This resin pipe joint A is a tightening that can visually recognize the end of tightening of the union nut 2 (or that the end is near) in the state of assembly in which the tube 3 is inserted and fixed with the union nut 2. An end recognition means C is provided. That is, while the union nut 2 is turned and tightened, the ring body 18 is set so that the tightening is finished when the ring body 18 starts to rotate. In short, the rotational movement of the ring body 18 is visually observed. When the confirmation is made, the tightening end recognition means C functions such as assembly OK.

  As shown in FIGS. 1 and 2, the ring body externally fitted on the mounting outer peripheral surface 1c is provided with a follow-up means D in which the ring body is rotated by a union nut 2 that is operated to rotate. When the circumferential edge 10 presses against the diameter change region 9 and the union nut 2 in which the seal portion S is formed is in a screwing end state (or a state immediately before), the ring body 18 is rotated by the union nut 2. The tightening end recognition means C is configured to start. The follower means includes an engaging protrusion 20 of the union nut 2 and an engaged protrusion 19 formed on the ring body 18 in a state in which the radial dimension of the engaging protrusion 20 is equal to the engagement protrusion 20. In the immediately preceding state, the engagement protrusion 20 starts to press the engagement protrusion 19.

  The operation of the tightening end recognition means C will be described. In a situation where the union nut 2 is tightened and screwed and the circumferential edge for pressing 10 starts to press the diameter change region 9 or immediately before that, FIG. As shown, the engaging protrusion 20 and the engaged protrusion 19 are in a positional relationship slightly separated in the axial direction. Further, in a situation where the union nut 2 is further tightened and the peripheral edge 10 for pressing presses the diameter-enlargement change region 9 to form the seal portion S, the engagement protrusion 20 is engaged as shown in FIG. The union nut 2 is screwed until it interferes with the projection 19 in the radial direction, and the ring body 18 is rotated and moved.

  Therefore, the operator can recognize that the resin pipe joint A is in the tightening end state by observing that the ring body 18 starts to rotate, thereby ending the union nut 2 turning operation. This is a function for notifying the operator that the tightening is completed by the tightening end recognition means C. That is, when the union nut 2 in which the seal portion S is formed is in the screwing end state or just before it, the ring body 18 is set to start rotating by the union nut 2. In short, the union nut 2 may be screwed onto the joint body 1 and rotated in the tightening direction, and the tightening may be terminated when the accompanying rotation of the ring body 18 can be observed.

  Then, when it is necessary to retighten the union nut 2 due to creep or the like over time, the union nut 2 is turned around while the ring body 18 is rotated from the state shown in FIG. It ’s fine. That is, since the ring body 18 is further pressed in the axial center P direction, the second ring portion 18b between the connecting portions 18c, 18c adjacent in the circumferential direction is bent (elastically deformed) in the axial direction. (Refer to FIG. 5) It is possible to allow the engagement protrusion 20 to enter the width of the ring body 18 in the axis P direction while rotating the ring body 18. As shown in FIG. 5, the additional tightening limit is a state where the ring body 18 is sandwiched between the outer peripheral flange 1A and the union nut 2 at the connecting portion 18c, that is, a tightening limit state. This is because the ring body 18 cannot be deflected and displaced (elastically deformed) in the direction of the axis P.

  That is, in the resin pipe joint A according to the first embodiment, the ring body 18 is sandwiched between the union nut 2 and the outer peripheral flange 1A from the screwing end state when the ring body 18 starts to be rotated and moved by the union nut 2. Until the screw reaches a tightening limit state in which further screwing is prevented, a tightening means E is provided that allows the union nut 2 to be operated by a predetermined amount in the tightening direction. More specifically, the structure of the ring body 18, that is, the engagement protrusion 20 is located in the middle between the connecting portions 18 c and 18 c adjacent to each other in the circumferential direction and can be flexibly displaced (elastically deformed) in the axis P direction. The two ring portions 18b are bent in the axial direction.

[Another Example]
The sizes, shapes, dimensions, and the like of the engaging protrusions 20 and the engaged protrusions 19 can be appropriately changed and set, and the number of them and the number of connecting portions 18c can be variously set. In addition, for example, a resin pipe joint in which the connecting portion 18c and the engaged protrusions are provided at two places, the possible bending amount in the direction of the axis P of the second ring portion 18b is increased, and the tightening amount is increased is also possible. .

Sectional drawing which shows the structure (tightening completion state) of the resin pipe joint by Example 1 FIG. 1 is a plan view showing the resin pipe joint of FIG. Front view showing ring body The top view of the resin pipe joint which shows just before a ring body rotates. Top view of resin pipe joint showing the tightening limit (tightening limit)

DESCRIPTION OF SYMBOLS 1 Joint main body 1A Outer peripheral flange 2 Union nut 2a Tip 3 Tube 3A Expanded diameter part 4 Fitting cylinder 5 Male thread 8 Female thread 9 Expanded diameter change area 10 Sealing pressing part 18 Ring body 18a First ring part 18b Second ring part 18c Connection Part 19 Engagement protrusion 20 Engagement protrusion C Tightening end recognition means D Follow-up means E Retightening means P Shaft center S Seal part

Claims (6)

A synthetic resin joint body comprising a fitting tube that can be fitted and mounted by expanding the end of the synthetic resin tube, and a male screw, and
A union nut made of a synthetic resin provided with a female screw that can be screwed into the male screw, and a sealing pressing portion that can act on a diameter expansion change region in the diameter expansion portion of the tube;
As the union nut is screwed in the axial direction of the joint main body by screwing the female screw with the male screw in a state where the tube is fitted and attached to the fitting cylinder, the diameter expansion change region is A resin pipe joint configured to be pressed in the axial direction by a pressing portion for sealing to form a sealing portion,
A ring body that can be rotated around the shaft center is externally fitted to the joint body between the outer peripheral flange formed on the joint body and the tip end of the union nut that is screwed into the joint body. The ring body is provided with a rotating means that is rotated by the union nut that is equipped and operated, and the seal pressing portion presses the diameter-enlargement change region so that the seal portion is A resin pipe joint provided with a tightening end recognition means that is set so that the ring body starts to be pivoted and moved by the union nut when the union nut formed is in a state where it has ended or just before that. .   The follower means includes an engaging protrusion formed to protrude toward the ring body in the axial direction at the tip of the union nut, and an engaged protrusion formed to protrude from the ring body toward the union nut in the axial direction. 2. The resin pipe joint according to claim 1, wherein the engagement protrusion starts to press the engagement protrusion when the screwing end state or immediately before the screwing end state.   Tightening in which the ring body is sandwiched between the union nut and the outer peripheral flange from the state where the ring body starts to be rotated by the union nut to prevent further screwing. The resin pipe joint according to claim 1 or 2, further comprising means for tightening the union nut by a predetermined amount in a tightening direction until the limit state is reached.   The ring body is displaced in the circumferential direction with respect to the first ring portion along the outer peripheral flange, the second ring portion on the union nut side having the engaged protrusion, and the engaged protrusion in the circumferential direction. A connecting portion that connects the ring portion and the second ring portion, and the tightening means is configured such that a portion other than the connecting portion in the first ring portion is deformed in the axial direction, and the connecting portion 4. The resin according to claim 3, wherein the union nut can be turned until the ring body reaches the tightening limit state between the outer peripheral flange and the union nut. Pipe fittings.   5. The resin pipe joint according to claim 4, wherein each of the engagement protrusion, the engagement protrusion, and the connection portion is provided at four locations at equal intervals in the circumferential direction.   The resin pipe joint according to any one of claims 1 to 5, wherein the joint body and the union nut are made of a fluororesin.

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