JP2005291500A - Fusion type resin pipe coupling structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fusion type resin pipe coupling structure capable of sufficiently exhibiting the slipping-out preventive function of a tube member, capable of securing safety, and capable of simplifying fusion work of the tube member, even when abnormal fluid pressure and mechanical abnormal extraction force except for internal pressure are applied, by removing an obstacle to realizing high purity of fluid by solving the problem of gathering the fluid. <P>SOLUTION: An annular seal part 30 having a swelling part 31 abutting in a close contact shape on an inlet side seal part 25 by receiving the fastening action to a male screw 26 of a socket part 24 of a union nut 22 and a fitting projection part 32 abutting in a close contact shape on the innermost side seal part 27, is integrally molded by resin on the outer periphery of one end part 21a of the resin tube member 21 inserted into a through-passage 23 of a coupling body 20. The other end part 21b of the tube member 21 is formed into a fusion part butted against and fused on an end part of the other resin tube member 38. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a fusion-type resin pipe joint structure, and more specifically, a pipe or fluid of high-purity liquid or ultrapure water handled in manufacturing processes such as semiconductor manufacturing, medical / pharmaceutical manufacturing, food processing, chemical industry, etc. The present invention relates to a resin pipe joint structure that is suitably used for control devices and the like.

  As this type of resin pipe joint structure, for example, a structure as shown in FIGS. 3 and 4 (hereinafter referred to as “first conventional example”) is known (for example, see Patent Document 1). The resin pipe joint structure connects the filter 2 and its secondary side pipe 3 in a clean gas supply path 1 used in a semiconductor manufacturing apparatus or the like. That is, the pipe end portion 5 of the secondary side pipe 3 is inserted into the secondary side outlet portion 4 of the filter 2, and then screwed into the joint ring 6 fixed to the distal end side of the mouth portion 4 a of the secondary side outlet portion 4. By tightening the union nut 7 that has been tightened and pressing the bite ring 9 abutted against the tapered surface 8 of the joint ring 6 into the outer peripheral surface of the secondary side pipe 3, The secondary pipe 3 is connected in a sealed state with a biting ring 9.

  In addition, a fluid control device as shown in FIG. 5 (hereinafter referred to as “second conventional example”) is also known (see, for example, Patent Document 2). Resin connection ports 16 and 17 are provided on the liquid discharge side and the liquid discharge side, and resin tubes 18 and 19 for flow path construction are welded (welded) W to the connection ports 16 and 17 respectively. It is.

  However, in the resin pipe joint structure of the first conventional example in which the secondary side outlet portion 4 and the secondary side pipe 3 are connected in a sealed state by the biting ring 9 formed separately from the secondary side pipe 3, Although the biting ring 9 is pressed or bited into the outer peripheral surface of the secondary pipe 3 by tightening the union nut 7, there is a limit to the degree of pressure contact or biting of the biting ring 9 by tightening the union nut 7. A slight gap tends to occur between the inner peripheral surface of the biting ring 9 and the outer peripheral surface of the secondary side pipe 3. For this reason, the pressurized gas sent from the filter 2 enters the gap and becomes difficult to escape, resulting in a gas pool, which hinders gas purification. Further, when this resin pipe joint structure is used for a liquid supply pipe or the like, the liquid that has entered the gap is unlikely to come out and becomes a liquid pool, which hinders high purity of the liquid.

  Further, it is necessary to prevent the secondary side pipe 3 from coming out of the secondary side outlet portion 4 of the filter 2, and this retaining is achieved by press-contacting or biting into the outer peripheral surface of the secondary side pipe 3 of the biting ring 9. Although it is carried out, the means for preventing the secondary pipe 3 from coming off may not be sufficient depending on the use conditions. In other words, the pull-out resistance against the normally used fluid pressure applied to the secondary side pipe 3 is not a problem even with the above-described retaining means, but the temperature of the transported fluid exceeds the normal use temperature, or the fluid pressure is normally used. Safe when transporting dangerous chemicals, especially when abnormal fluid pressure is applied under severe operating conditions that far exceed the pressure of the product, or when mechanical pull-out force other than internal pressure is abnormally applied Ensuring sex is a very important issue. For this reason, it was necessary to limit the use conditions (temperature and pressure) of this resin pipe joint.

  Further, in the resin pipe joint structure of the first conventional example, the pull-out resistance of the secondary side pipe 3 is made only by pressing or biting into the outer peripheral surface of the secondary side pipe 3 of the biting ring 9 by tightening the union nut 7. However, this causes a safety problem when the tightening force of the union nut 7 becomes weak due to an initial construction error or a change over time. In particular, when the secondary side pipe 3 is made of a fluororesin (PFA or the like) that is excellent in heat resistance and chemical resistance, the friction coefficient is small and slippery.

In the fluid control device of the second conventional example shown in FIG. 5, since the resin connection ports 16 and 17 project integrally from the liquid input side and the liquid discharge side of the control device main body 15, the connection ports 16 and 17 are provided. Even if a fusing machine is used for fusing the resin tubes 18 and 19, the controller body 15 is bulky and obstructs the fusing work, so that the fusing work is difficult to perform. In addition, the resin connection ports 16 and 17 have the disadvantage that only the resin tubes 18 and 19 having the same diameter can be fused, and the resin tubes having different diameters cannot be fused.
JP 2001-141143 A (FIGS. 1 and 3) Japanese Patent Laid-Open No. 2002-156087 (FIGS. 1 and 2)

  The present invention has been made in order to solve such a problem, and its object is to provide a seal between a tube member and a joint body constituting a secondary side pipe or the like as in the first conventional example. By devising the structure and the tube member retention means, it is possible to eliminate the problem of gas and liquid pooling and eliminate the obstacles to high purity of the fluid, as well as abnormal fluid pressure and internal pressure. Even when a mechanical abnormal pulling force other than the above is applied, the tube member's retaining function can be fully exerted to ensure safety, there are no restrictions on the use conditions, and it can be used in all conditions and the design freedom An object of the present invention is to provide a fusion-type resin pipe joint structure in which the number of welds increases. Another object of the present invention is to provide a fusion-type resin pipe joint structure that can simplify the fusion work of tube members and enables fusion of different-diameter tube members.

  The fusion-type resin pipe joint structure of the present invention has a through-passage, a joint main body provided with a receiving portion at one end of the through-passage, and a resin tube inserted into the through-passage of the joint main body A union nut having a member, a female screw that is loosely fitted to the outer periphery of the tube member, and is screwed to a male screw on the outer periphery of the receiving portion, and an annular inward flange portion projecting inwardly at one end portion In the resin pipe joint structure comprising: a tapered inlet-side seal portion that gradually increases in diameter toward the outside of the receiving portion on the inner periphery of the opening end of the receiving portion; At least one inner back side seal portion is provided inward from the inlet side seal portion, and the inward flange is fastened to the outer periphery of one end portion of the tube member by tightening the male nut of the receiving portion of the union nut. In close contact with the inlet-side seal part under the pressing action of the part An annular seal portion having a bulging portion that comes into contact and a fitting convex portion that comes into close contact with the inner back side seal portion is integrally processed, and protrudes outward from the receiving portion of the tube member. The other end portion is characterized in that it is a fusion portion that is abutted and fused with an end portion of another resin tube member.

In this case, the annular seal portion and the tube member can be integrally molded with resin. Moreover, the said annular seal part can also be integrally processed by the said tube member by cutting. Moreover, the said annular seal part can also be integrally processed by welding to the said tube member.
In addition, the outer end surface of the bulging portion is formed vertically, and the corner portion where the vertical outer end surface of the bulging portion intersects the outer surface of the other end portion of the tube member extending axially outward from the outer end surface. A thick wall portion having an outer diameter larger than the outer diameter of the other end portion of the tube member and smaller than the outer diameter of the bulging portion can be attached to the tube member so that the tube member is not easily bent at the corner portion as a bending point. .

  According to the fusion-type resin pipe joint structure having the above-described structure, the union nut is tightened to tightly contact the bulging portion that is in close contact with the inlet-side seal portion of the joint body and the inner back-side seal portion. An annular seal portion having a fitting convex portion that comes into contact is integrally processed on a part of the outer periphery of the tube member so that no gap is generated between the outer periphery of the tube member and the annular seal portion. Therefore, there is no fluid pool problem as in the conventional resin pipe joint structure described above, and the obstacle to high purity of the fluid can be removed.

  In addition, even when an abnormal mechanical pressure other than abnormal fluid pressure or internal pressure is applied to the tube member, the annular seal portion pressed by the inward flange of the union nut is integrally processed on the tube member. Therefore, it can sufficiently counter the pulling force, and the tube member's pulling-out prevention force is enhanced to ensure safety, and there are no restrictions on the use conditions (temperature, pressure), and it can be used in all conditions and is designed. The degree of freedom can be increased.

  The tube member and the joint body can be separated, and the end of another resin tube member can be abutted and fused to the fused part of the other end of the tube member in this separated state. Even when a fusing machine is used for wearing, the fusing operation can be easily performed. In addition, when fusing another resin tube member having a different diameter from the tube member, the diameter of the other end of the tube member is formed to be the same as the diameter of the other resin tube member having a different diameter. Is possible.

  Preferred embodiments of the present invention will be described below with reference to the drawings.

[Example 1]
FIG. 1 shows one embodiment. In this embodiment, the present invention is applied to a resin pipe joint structure in a supply path 1 of a clean gas used in a semiconductor manufacturing apparatus or the like as in the conventional example shown in FIG. This is a fusion-type resin pipe joint structure that connects the filter 2 constituting the upstream portion and the secondary pipe 3 constituting the downstream portion thereof. The filter 2 itself is the same as the filter shown in FIG. 3, and a pressurized gas (nitrogen, air, inert gas) corresponding to the intended use from the primary side pipe not shown in the filter housing 10 by an appropriate filter member 11. Etc.) and a secondary side space 13 from which the pressurized gas that has passed through the filter member 11, that is, the cleaned clean gas, flows out.

  That is, the fusion-type resin pipe joint structure according to the present invention in this embodiment is a joint body 20 integrally formed at the distal end side of the secondary side outlet portion 4 communicating with the secondary side space 13 of the filter 2. And the tube member 21 and the union nut 22 which comprise the secondary side piping 3 are provided. The joint body 20, the tube member 21, and the union nut 22 are formed of a fluororesin (for example, PFA, PTFE, PVDF, etc.) excellent in heat resistance and chemical resistance, or other resins.

  The joint body 20 has a through-passage 23, a receiving portion 24 is provided at one end of the through-passage 23, and a taper that gradually increases in diameter toward the outside of the receiving portion on the inner periphery of the opening end of the receiving portion 24. A shaped inlet-side seal portion 25 is provided. A male screw 26 is formed on the outer periphery of the receiving portion 24. At least one inner back side seal portion 27 is provided inward from the inlet side seal portion 25 of the receiving port 24. In the illustrated example, the inner back side seal portion 27 has an annular first shape formed in a V-shaped cross section having a tapered surface 27a gradually decreasing in the inner back portion of the receiving portion 24 toward the receiving portion. One inner back side seal portion 27A is provided.

  The union nut 22 is formed with a female screw 28 screwed to the male screw 26 of the joint body 20 on the inner periphery thereof, and an annular inward flange portion 29 is formed inwardly at one end portion. Further, the inner peripheral surface of the one end portion 21 a of the tube member 21 and the inner peripheral surface of the pipe passage 23 of the joint body 20 are set to be flush with each other.

  The tube member 21 is formed by integrally molding an annular seal portion 30 on the outer periphery of one end portion 21a thereof. The annular seal portion 30 is formed continuously on the bulging portion 31 formed on the inner end side with a tapered surface 31a contacting the inlet-side seal portion 25 of the joint body 20, and on the tapered surface 31a side of the bulging portion 31. A tapered surface 32a that contacts the tapered surface 27a of the inner back side seal portion 27A of the joint body 20 is formed to have a fitting convex portion 32 formed on the inner end side. The other end portion 21b of the tube member 21 is a fusion portion that is abutted and fused with an end portion of another resin tube member 38.

  In the fusion-type resin pipe joint structure having the above-described configuration, one end part of another resin-made tube member 38 is fused in a butting manner to the fusion part of the other end part 21b of the tube member 21, When the tube member 21 is inserted through the receiving portion 24 of the joint body 20 or when the tube member 21 has already been temporarily inserted into the joint body 20, the union nut 22 is loosened and the tube member 21 is temporarily joined. After being extracted from the main body 20, the fusion W is performed. For the fusion, for example, a fusion machine using infrared heating is used. In this case, since the tube member 21 is separated from the joint body 20, the joint body 20 does not get in the way at the time of fusion and can be easily fused.

  The fusion bonding is not limited to the inner diameter of the one end portion 21a of the tube member 21 and the inner diameter of the other resin tube material 38, but is different from the inner diameter of the one end portion 21a of the tube member 21. The resin tube member 38 can also be fused.

  Thus, the one end portion 21 a of the tube member 21 is inserted into the receiving portion 24 of the joint body 20, and the female screw 28 of the union nut 22 that has been loosely fitted to the outer periphery of the tube member 21 in advance is screwed onto the male screw 26 of the joint body 20. Tighten together. Then, the inward flange portion 29 of the union nut 22 abuts on the outer end surface 31b perpendicular to the axis X of the bulging portion 31 of the tube member 21, and the entire tube member 21 together with the annular seal portion 30 is strongly pressed toward the joint body 20 side. Press.

  Due to the strong pressing action by tightening the union nut 22, the taper surface 32 a of the fitting convex portion 32 becomes the taper surface 27 a of the first inner back side seal portion 27 A of the joint body 20, and the taper surface 31 a of the bulge portion 31 becomes. The joint main body 20 is tightly sealed with a strong surface pressure and sealed in an airtight manner, and the tapered surface 32a of the fitting convex portion 32 is pressed against the tapered surface 27a of the first inner back side sealing portion 27A. As a result, the inner back side seal portion 27A is reduced in diameter. Therefore, it is possible to reliably prevent the fluid flowing out from the secondary outlet portion 4 of the filter 2 to the tube member 21 from leaking between the through-passage 23 of the joint body 20 and the outer periphery of the tube member 21 to the outside.

  Thus, according to the fusion-type resin pipe joint structure that connects the secondary outlet portion 4 of the filter 2 and the tube member 21 in a sealed state, the inlet-side seal portion of the joint body 20 is tightened by tightening the union nut 22. 25 and the inner seal portion 27 that are in close contact with the inner seal portion 27 are integrally formed on the outer periphery of the tube member 21 and do not form a gap with the tube member 21. Thus, it is possible to solve the problem of fluid accumulation such as the conventional resin pipe joint structure, and to contribute to the purification of the fluid.

  Further, the annular seal portion 30 which is integrally formed with the tube member 21 and pressed by the inward flange portion 29 of the union nut 22 has a mechanical abnormal pulling force other than abnormal fluid pressure and internal pressure. Even when it is applied to the member 21, it can sufficiently resist the pulling force and can increase the pulling resistance of the tube member 21, and can be used not only at normal temperature fluid but also at high temperature and high pressure fluid usage conditions. it can.

  In the annular seal portion 30 of the tube member 21, as shown in FIG. 1, when the outer end surface 31 b of the bulging portion 31 is formed perpendicular to the axis X, the inner surface of the inward flange portion 29 of the union nut 22. Therefore, the bulging portion 31 can be stably and reliably pressed by the inward flange portion 29 as the union nut 22 is tightened, and the pressing state can be secured. However, the tube member 21 is easy to bend at the corner where the tube member 21 intersects the vertical outer end surface 31b of the bulging portion 31 and the outer surface of the other end portion 21b extending axially outward from the outer end surface 31b. There is a demerit that the outer end surface 31b of the bulging portion 31 is easily separated from the inner surface of the inwardly facing flange portion 29 of the union nut 22 by bending.

  Therefore, at the corner where the perpendicular outer end surface 31b of the bulging portion 31 and the outer surface of the other end portion 21b intersect, the outer diameter is larger than the outer diameter of the other end portion 21b and smaller than the outer diameter of the bulging portion 31. It is preferable to attach the meat portion 33. By attaching the thick portion 33 in this way, it is possible to suppress the tube member 21 from being bent with the entering corner as a bending point as much as possible. Therefore, there is no problem that the outer end surface 31b of the bulging portion 31 is separated from the inner surface of the inward flange portion 29 of the union nut 22 due to the bending of the tube member 21, and the inward flange portion 29 of the union nut 22 is always bulged. Thus, it is possible to reliably maintain the state of being pressed against the outer end surface 31b of 31.

  Moreover, in order to hold | maintain the contact | abutting engagement state of the inward flange part 29 of the union nut 22 and the perpendicular | vertical outer end surface 31b of the bulging part 31 more reliably, the inner surface of the inward flange part 29 of the union nut 22 is maintained. A convex portion 34 is provided on the outer end surface 31 b of the bulging portion 31, while a concave portion 35 is provided on the inner surface of the inward flange portion 29. It is preferable to keep it.

[Example 2]
(Modification example of fitting convex part of tube member and inner back side seal part of joint body)
In addition to the above-described embodiment, the fitting protrusion 32 of the tube member 21 and the inner back side seal portion 27 of the joint body 20 may employ an embodiment as shown in FIG. That is, as shown in FIG. 2, the inner back side seal portion 27 of the joint body 20 is formed in a tapered shape that gradually increases in diameter toward the mouth portion in the inner portion of the mouth portion 24 of the joint body 20. A first inner back side seal portion 36A and a third inner back side seal portion 36C formed of an annular groove parallel to the axis X are formed.

  On the other hand, in the fitting convex part 32 of the tube member 21, the 1st fitting convex which has the taper surface which contact | abuts the 1st inner back side seal part 36A in the taper surface 31a side of the bulging part 31 of the tube member 21. 32A and the protrusions 32A project radially outward and inward in the axial direction, and press-fit into the third inner back seal portion 36C to generate radial surface pressure. A cylindrical second fitting protrusion 32B is formed. Further, the inner peripheral surface of the one end portion 21 a of the tube member 21 and the inner peripheral surface of the pipe passage 23 of the joint body 20 are set to be flush with each other.

  In addition, only the outer peripheral surface of the second fitting convex portion 32B may be brought into close contact with the third inner back side seal portion 36C to constitute the seal portion.

(Example of tube member forming)
By forming a pair of tube members having an annular seal portion symmetrically, and cutting the center portion of the tube members after forming, two tube members having required shapes can be obtained.

(Variation of integrated processing means for tube member and annular seal part)
As means for integrally processing the annular seal portion 30 on the outer periphery of the one end portion 21a of the tube member 21, instead of integrally molding the tube member 21 and the annular seal portion 30 integrally, one end portion of the tube member 21 by cutting is used. It is optional to integrally process the annular seal portion 30 on the outer periphery of 21a, or to form the annular seal portion 30 separately from the tube member 21 and to weld the annular seal portion 30 to the outer periphery of the tube member 21. .

(Modification of joint body)
The joint body 20 having the resin pipe joint structure according to the present invention is not limited to the socket shape in which the through passage 23 is formed in the direction of the axis X as shown in the illustrated examples. Resin that can be applied to a shape, elbow shape, or cross shape that forms a through passage in a cross shape, and that protrudes integrally with a fluid control device such as a flow meter or pressure gauge other than the filter 2 The present invention can be similarly applied to pipe joints or resin pipe joints separate from the fluid control devices.

FIG. 2 is a cross-sectional view of a half cutaway view of a resin pipe joint structure according to an embodiment of the present invention (Example 1). A half cut-away cross-sectional view corresponding to FIG. 1 showing a modified example of the fitting convex part of the tube member and the inner back side seal part of the joint body (Example 2) Sectional view of conventional resin pipe joint structure Sectional view of another conventional resin pipe joint structure Sectional view of still another conventional resin pipe joint structure

Explanation of symbols

DESCRIPTION OF SYMBOLS 20 Joint main body 21 Tube member 21a One end part of a tube member 21b The other end part of a tube member 22 Union nut 23 Through-passage 24 Receptacle part 25 Inlet side seal part 26 Male thread 27 Inner back side seal part 28 Female thread 29 Inward flange part 30 Annular seal part 31 bulge part 32 fitting convex part 33 thick part 38 Other resin tube members

Claims (5)

A joint body having a through-passage and having a receiving portion at one end of the through-passage, a resin tube member inserted through the through-passage of the joint body, and loosely fitted on the outer periphery of the tube member, In a resin pipe joint structure having a female screw that is screwed to a male screw on the outer periphery of the receiving part, and a union nut having an annular inward flange projecting inwardly at one end part,
A tapered inlet-side seal portion that gradually increases in diameter toward the outside of the receiving portion is provided on the inner periphery of the opening end of the receiving portion. Each side seal part is provided,
A bulging portion that is pressed against the inlet side seal portion in close contact with the outer periphery of one end portion of the tube member by receiving a pressing action by the inward flange portion by tightening the receiving portion of the union nut to the male screw; The annular seal portion having a fitting convex portion that comes into close contact with the inner back side seal portion is integrally processed,
The other end portion of the tube member that protrudes outward from the receiving portion is a fusion portion that is abutted and fused with an end portion of another resin tube member. Pipe joint structure.   The fusion-type resin pipe joint structure according to claim 1, wherein the annular seal portion and the tube member are integrally molded with resin.   The fusion-type resin pipe joint structure according to claim 1, wherein the annular seal portion is integrally formed with the tube member by cutting.   The fusion-type resin pipe joint structure according to claim 1, wherein the annular seal portion is integrally processed by welding to the tube member. The outer end surface of the bulging portion is formed vertically, and a corner portion where the vertical outer end surface of the bulging portion intersects with the outer surface of the other end portion of the tube member extending axially outward from the outer end surface, The fusion-type resin according to any one of claims 1 to 4, wherein a thick-walled portion having an outer diameter larger than the outer diameter of the other end portion of the tube member and smaller than the outer diameter of the bulging portion is attached. Pipe joint structure.

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