JP2010216493A - Resin pipe connector - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a resin pipe connector formed to be confirmed that a union nut is completely fastened or in a state near thereto even in a work site under noisy condition and improved to be excellent in assembling workability and handling performance. <P>SOLUTION: This resin pipe connector is structured that a diameter enlarging region 9 is to be pushed by a sealing push part 10 with screw-advancement of a union nut 2 by screwing a female screw 8 and a male screw 5 to each other in the state of fitting a tube 3 on an inner cylinder 4 to generate an enlarged diameter part 3A. The tip of the union nut 2 is provided with a fastening completion recognizing means C formed with an abutment deforming part 18 to be bent for deformation with abutment of a connector body 1 on a peripheral flange 1A by screw-advancement, and set so that the abutment deforming part 18 starts to abut on the peripheral flange 1A in the state that screw-advancement of the union nut 2 formed with a seal part S is completed. <P>COPYRIGHT: (C)2010,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 object of the present invention resides in a point.
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.
Either the outer peripheral flange 1A formed on the joint body 1 or the end of the union nut 2 in the axial center P direction is brought into contact with the other by the screwing in the axial center P direction. An abutting deformation portion 18 that is bent and deformed is provided, and the union nut 2 in which the seal portion S is formed by the seal pressing portion 10 pressing the diameter-enlarged change region 9 or the unscrewed state of the union nut 2 is formed. A tightening end recognizing means C is provided, which is set so that the contact deforming portion 18 starts to contact the other in the immediately preceding state.

  According to a second aspect of the present invention, in the resin pipe joint according to the first aspect, the contact deformation portion 18 is separated from the one side by a predetermined distance in the direction of the axis P via the leg portion 18c, and the shaft A ring portion 18a formed of a material having flexibility with respect to the center P and facing away from the leg portion 18c in the circumferential direction with respect to the axis P. The ring portion 18a includes a contact portion 18b that protrudes from the ring portion 18a.

  According to a third aspect of the present invention, in the resin pipe joint according to the second aspect, the contact portion 18b is disposed in the center in the circumferential direction in a portion of the ring portion 18a that does not have the leg portion 18c. It is characterized by this.

  According to a fourth aspect of the present invention, in the resin pipe joint according to any one of the first to third aspects, the one is an end portion in the axial center direction of the union nut 2 and the other is the outer peripheral flange 1A. It is characterized by being.

  The invention according to claim 5 is the resin pipe joint according to any one of claims 1 to 4, wherein the joint body 1 and the union nut 2 are made of a fluororesin.

  According to the invention of claim 1, although described in detail in the section of the embodiment, when the union nut is turned in the tightening direction to push the tube and form the seal portion by the function of the tightening end recognition means, A situation appears in which the contact deformed portion provided on one of the joint body and the union nut contacts the other. Therefore, it is possible to recognize that the union nut has been tightened by visually confirming that the abutting deformation portion has abutted against the other. 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. In this case, if the abutment deforming portion is provided on the union nut as in claim 4, it is easier to manufacture and rational than providing it on the joint body.

  According to the second aspect of the present invention, since the flexible ring portion exists away from the one side in the axial direction, the union nut turning is still operated after the contact portion contacts the other. However, since the ring portion can be absorbed by being elastically deformed in the axial direction, there is an advantage that it is possible to avoid the inconvenience that the contact deformation portion or the other is damaged. In addition, there is also an advantage that the union nut can be retightened.

  According to invention of Claim 3, since the contact part is arrange | positioned in the center in the circumferential direction in the part which does not have the leg part of a ring part, compared with the case where it arrange | positions other than a center, the axis | shaft of a ring part The amount of elastic deformation in the center direction can be increased, and therefore, there is an advantage that a large amount of additional tightening can be secured efficiently while obtaining the effects of the first and second aspects of the invention.

  According to the invention of claim 5, 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 a resin pipe joint of Example 1, FIG. 2 is a plan view of the resin pipe joint, FIG. 3 is an axial direction view showing only a gauge ring portion of a union nut, and FIG. FIG. 5 is a plan view of a resin pipe joint showing a state before tightening, and FIG. 5 is a plan view of the resin pipe joint showing a tightened state.

[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 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 two parts including a union nut 2 made of resin. 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 formed with a mechanism outer peripheral surface 1c having a diameter equal to or larger than the thread diameter of the male screw 5 following the male thread side surface 1a of the outer peripheral flange 1A. Has been. This is a component for fitting a gauge ring portion 18 (described later) of the union nut 2 so as to be capable of rotational movement, and the gauge ring portion (an example of a contact deformation portion) 18 by the union nut 2 being screwed. Functions as a place of action of a tightening end recognition means C (described later), which is formed by abutting the outer peripheral flange 1A in contact with the outer peripheral flange 1A.

  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, a sealing peripheral edge (an example of a pressing portion for sealing) 10, a retaining peripheral edge 11, and a presser An inner peripheral portion 13, a guide tube portion 14, and a gauge ring portion 18 are provided. The sealing peripheral edge 10 is a portion capable of being pressed in the direction of the axis P by contacting the small diameter side end portion of the diameter expansion change region 9 in the diameter expansion portion 3A fitted on the inner cylinder 4 of the tube 3. The retaining peripheral edge 11 is a portion that can be pressed in the direction of the axis P by contacting the large-diameter side end portion of the diameter expansion change region 9. The presser inner peripheral portion 13 is a place that can be externally fitted to the enlarged diameter straight portion 12 surrounded by the straight barrel portion 4B having a constant diameter in the enlarged diameter portion 3A. The guide cylinder portion 14 is a location that surrounds the tube 3 over a predetermined length in the direction of the axis P following the sealing peripheral edge 10. The gauge ring portion 18 is a portion that bends and deforms in the direction of the axis P along with the contact with the outer peripheral flange 1 </ b> A due to screwing of the union nut 2. In addition, 2A is a union nut main body by which the outer peripheral surface was given the non-slip process, 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 That is, although it is set to a value smaller than the diameter of the presser inner peripheral portion 13, it may not be (for example, smaller diameter than the outer peripheral surface 4 b), and if it acts on the larger diameter side portion of the diameter expansion change region 9. good. 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.

  1-3, the gauge ring part 18 is formed in the front-end | tip part of the internal thread side end used as the screwing side of 1 to the coupling main body of the union nut 2, and four leg parts are provided in the end surface 2a. The ring portion 18a is formed integrally with the ring portion 18c, and the four contact portions 18b are formed integrally with the ring portion 18a. The ring portion 18a is a flat plate donut-shaped portion with a thin wall thickness in the direction of the axis P, and is disposed slightly away from the union nut body 2A in the direction of the axis P via the leg portion 18c.

  The leg portion 18c has a slight circumferential length with respect to the axis P at every equal angle (90 degrees) with respect to the axis P, and the same radial dimension as the ring portion 18a. It is a part for connecting 18a smoothly and integrating, that is, a connecting part. The abutting portion 18b protrudes from the ring portion 18a toward the outer peripheral flange 1A side in the axis P direction at every equal angle (90 degrees) positioned at the center between the leg portions 18c adjacent in the circumferential direction. It is integrally formed. The radial dimension is substantially half of the ring portion 18a, and the ring portion 18a and the outer peripheral surface are made to coincide with each other.

  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 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. Note that the pressing by the retaining peripheral edge 11 and the pressing by the sealing peripheral edge 10 may be performed simultaneously.

  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 recognized (in the case of a thin wall). 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. In other words, while the union nut 2 is turned and tightened, it is set so that the tightening is completed when it is compressed and deformed in the direction of the axis P of the gauge ring 18. The tightening end recognizing means C functions as if assembly is OK if the deformation is visually confirmed.

  As shown in FIGS. 1 and 2, the gauge ring portion 18 that is a contact deformation portion is separated from the union nut main body 2 </ b> A that is one side by a predetermined distance in the direction of the axis P via the leg portion 18 c, and the axis P A ring portion 18a formed in an annular shape, and a ring portion 18a that protrudes from the leg portion 18c toward the outer peripheral flange 1A side at a position away from the leg portion 18c in the circumferential direction. And a contact portion 18b. When the seal peripheral edge 10 presses against the diameter change region 9 and the union nut 2 in which the seal portion S is formed reaches the end of screwing or immediately before the tightening end recognition means C, The contact portion 18b is configured to start to contact the male thread side surface 1a of the outer peripheral flange 1A.

  The operation of the tightening end recognition means C will be described. In a situation immediately before the pressing peripheral edge 10 starts to press the diameter expansion change region 9 by tightening and screwing the union nut 2, as shown in FIG. The contact portion 18b and the outer peripheral flange 1A are in a positional relationship that is slightly separated in the direction of the axis P. Further, when the union nut 2 is turned in the tightening direction (rightward direction) and the pressing peripheral edge 10 presses the diameter-enlargement change region 9 to form the seal portion S (or the situation immediately before), FIG. As shown in FIG. 2, the union nut 2 is screwed until the contact portion 18b just contacts the outer peripheral flange 1A (the contact portion 18b and the outer peripheral flange 1A interfere in the radial direction).

  Therefore, the operator can recognize that the resin pipe joint A has been tightened by observing that the gauge ring portion 18 has come into contact with the outer peripheral flange 1A, thereby completing the turning operation of the union nut 2. To do. This is a function for notifying the operator that the tightening is completed by the tightening end recognition means C. The contact portion 18b is located in the middle between the adjacent leg portions 18c in the circumferential direction, and is made of flexible PTFE and can move in the axis P direction by elastic deformation of the ring portion 18a. Even if the union nut 2 is slightly turned in the tightening direction after the contact portion 18b contacts the outer peripheral flange 1A, the ring portion 18a is elastically deformed (see FIG. 5) and absorbed. Therefore, it is possible to provide a tightening end recognition means C that is set in such a manner that when the elastic deformation of the ring portion 18a is observed, the tightening is finished and the turning operation is finished.

  In the resin pipe joint A, the union nut 2 can be tightened to cope with a decrease in the pressing action of the tube 3 by the sealing peripheral edge 10 due to a change with time. That is, by the configuration in which the ring portion 18a can be elastically deformed in the direction of the axis P as described above, additional tightening by further turning the union nut 2 from the tightening end state shown in FIG. 2 is possible. As shown in FIG. 5, the additional tightening limit is a state in which the gauge ring 18 is sandwiched between the outer peripheral flange 1A and the union nut body 2A at the leg portion 18c, that is, a tightening limit state. This is because the ring portion 18a cannot be deflected and displaced (elastically deformed) in the axial center P direction.

[Another Example]
A resin pipe joint having a configuration in which the gauge ring portion 18 is mounted on the outer peripheral flange 1A is also possible. The structure and shape of the gauge ring portion (contact deformation portion) can be variously changed, and are not limited to the illustrated configuration.

Sectional drawing which shows the structure (tightening completion state) of the resin pipe joint by Example 1 Plan view of the resin pipe joint in FIG. Axial direction view showing only the gauge ring part of the union nut The top view of the resin pipe joint which shows the state before the contact part contacts the outer peripheral flange Top view of the resin pipe joint showing the tightened state

DESCRIPTION OF SYMBOLS 1 Joint body 1A Outer flange 2 Union nut 3 Tube 3A Expanded diameter part 4 Fitting cylinder 5 Male screw 8 Female thread 9 Expanded diameter change area 10 Sealing pressing part 18 Abutting deformation part 18a Ring part 18b Abutting part 18c Leg part C Tightening End recognition means P shaft center S seal part

Claims (5)

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,
Abutment that bends and deforms in the axial direction along with the abutment on either one of the outer peripheral flange formed on the joint body or the axial end of the union nut by the screwing. A deforming portion is provided, and when the seal pressing portion presses the diameter-enlargement change region and the union nut in which the seal portion is formed is in a screwing end state or just before that, the contact deforming portion A resin pipe joint provided with a tightening end recognizing means which is set so as to start contacting the other.   A ring portion formed of a flexible material, wherein the contact deformation portion is spaced apart from the one side by a leg portion in the axial direction and has an annular shape with respect to the axial center. The contact part which protrudes from the said ring part in the state which faced the said other side in the position which left | separated from the said leg part in the circumferential direction regarding the said axial center is comprised. Resin pipe fittings.   The resin pipe joint according to claim 2, wherein the contact portion is disposed in the center in a circumferential direction in a portion of the ring portion that does not have the leg portion.   The resin pipe joint according to any one of claims 1 to 3, wherein the one is an axial end portion of the union nut, and the other is the outer peripheral flange.   The resin pipe joint according to any one of claims 1 to 4, wherein the joint body and the union nut are made of a fluororesin.

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