JP2009243493A - Pipe connection structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a pipe connection structure composing an inexpensive pipe structure. <P>SOLUTION: A rubber tube 5 is composed of a rubber inner layer 73, an intermediate resin barrier layer 77, and a rubber outer layer 75. The tube connection part 13 of a quick connector 3 is relatively inserted into a non-adhesive part between the resin barrier layer 77 and the rubber inner layer 73. The rubber outer layer 75 and resin barrier layer 77 are tightly fitted over the whole periphery of the tube connection part 13, and the rubber inner layer 73 enters over the whole length of the large diameter part 31 of the tube connection part 13. The insertion end 83 of a pipe body 7 is relatively inserted into the quick connector 3 and a retainer 11 from the axial other side, and the rubber inner layer 73 is compressed by being sandwiched between the insertion end 83 of the pipe body 7 and the large diameter part 31. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a pipe connection structure used for connecting a gasoline fuel pipe of an automobile, for example.

  As a connection structure for connecting a tube (fluid piping member) and a pipe body with a fluid pipe such as a gasoline fuel pipe, an annular outer peripheral surface of the insertion end of the pipe body is described, for example, in Patent Document 1 An engagement protrusion is formed, and the insertion end of the pipe body is relatively inserted and fitted into the connector so that the annular engagement protrusion snap-engages with the retainer means of the connector. Is used, and a tube fitted to the tube connection portion of the connector is connected to the pipe body through such a connection between the connector and the pipe body.

  In this pipe connection structure, in order to shorten the length of the connection part and make the pipe structure compact, the insertion end of the pipe body is relatively inserted into the connector until it reaches the inner periphery of the tube connection part. And is configured to be connected. In order to effectively seal between the tube connecting portion of the connector and the insertion end portion of the pipe body, a plurality of sealing O-rings are arranged in the tube connecting portion.

  As a tube fitted to the tube connecting portion of the connector, a rubber tube (rubber hose) excellent in flexibility as described in Patent Document 2, for example, is preferable. Such a rubber tube can also be easily bent using a mandrel, and can also be processed into a shape whose diameter gradually changes. However, since a rubber tube cannot secure a sufficient tightening force for the tube connection portion when fitted to the tube connection portion, the fitting portion to the tube connection portion needs to be fastened and fixed with a clamp member. . However, in automobile piping, etc., the piping connection structure must be configured in a narrow area where parts are densely packed, so it is not possible to attach a clamp member that protrudes outward to the outer periphery of the end of the rubber tube For this reason, resin tubes are often used.

JP 2005-155910 A JP2007-292303

  However, in a resin tube, a bellows portion must be formed in order to give flexibility to the tube. In addition, when the tube is formed in a bent shape in advance, after the bellows portion is formed in the tube, the tube is accommodated in a mold and heated to form a necessary bent shape. It is complicated. Therefore, when such a resin tube is used, the piping structure becomes expensive. Furthermore, it is difficult to form a shape whose diameter gradually changes with a resin tube. For example, when such a bellows resin tube is used for a filler pipe, foaming occurs in the injected fuel due to the bellows part, resulting in poor lubrication. There is also a fear.

  Moreover, the connector used here is assembled as shown, for example in FIG. That is, first, an O-ring C, a spacer bushing D, another O-ring E and a cylindrical bushing F are assembled into the tube connecting part B of the connector housing A from one axial end side (a) and sealed on one axial side. A connector housing A having a structure is configured (b). Next, the retainer H is disposed in the retainer holding portion G of the connector housing A from the other side in the axial direction (c), and the connector I is assembled (d). Then, as shown in FIG. 8, the piping tube J is tightly fitted on the outer periphery of the tube connecting portion B of the connector I configured as described above (a), and the piping tube K with connector is configured (b).

  Here, the O-ring C, the spacer bush D, another O-ring E, and the cylindrical bush F are not integrated into the tube connecting portion B at a time, but are temporarily installed in the tube connecting portion B one by one. We press-fit and finally incorporate these interior parts. Therefore, when the connector having such a structure is used, not only the number of interior parts is large, but also the work for assembling the interior parts takes time, so the connector becomes expensive and the cost of pipe connection increases. Further, when the number of O-rings is reduced to reduce the cost of assembling interior parts, the sealing function between the insertion end of the pipe body and the tube connecting portion of the connector is lowered.

  Accordingly, an object of the present invention is to provide a pipe connection structure that can eliminate at least one of such disadvantages.

  In order to achieve this object, the pipe connection structure of the present invention includes a connector in which a tubular tube connection portion is formed on one side in the axial direction and retainer means is provided on the other side in the axial direction, and the tube connection of this connector A pipe connection structure comprising: a pipe tube connected to a portion; and a pipe body having an insertion end portion inserted relatively to the connector from the other side in the axial direction and retained by the retainer means. The piping tube is a rubber tube having a laminated structure having a rubber inner layer and a rubber outer layer laminated on the outer side of the rubber inner layer, and the rubber inner layer is formed on the tube connecting portion. It is fitted to the inner periphery, and the rubber outer layer is connected to the tube connecting portion in a state of tightly covering the outer periphery of the tube connecting portion, and the insertion end of the pipe body is Serial is inserted into the connector so as to extend to the tube connecting portion, in which the rubber inner layer is sandwiched so as to compress between the tube connecting portion. The rubber outer layer is tightly covered or fitted to the outer periphery of the tube connection part, and the rubber inner layer is sandwiched between the insertion end of the pipe body and the tube connection part, so that the rubber tube is connected to the tube connection part of the connector. Therefore, the rubber tube and the tube connecting portion can be prevented from coming off and connected without using a clamp member for fastening the end of the rubber tube. Further, a space between the insertion end of the pipe body and the connector is sealed by using a rubber inner layer of the rubber tube as a sealing means. Since the rubber inner layer of the piping tube is used as a sealing means, O-rings and bushes in the tube connecting portion can be omitted, or the number of O-rings can be reduced. Furthermore, since the pipe body and the connector (tube connection part) are prevented from rotating via the rubber inner layer, the pipe body and the connector are relatively rotated by transmission of engine vibration or the like to the pipe connection part. (Because a rubber tube is used as the piping tube, vibration is absorbed by the rubber tube, and the transmission of vibration to the pipe connection itself is mitigated, thus increasing the detent effect) . Therefore, for example, when an O-ring is provided in the tube connecting portion, wear of the O-ring can be effectively prevented. Moreover, in this piping connection structure, the sealing means can be configured at the same time when the piping tube is fitted to the tube connecting portion of the connector.

  It is preferable that the axial length of the rubber inner layer of the piping tube fitted into the inner periphery of the tube connecting portion exceeds half of the axial length of the tube connecting portion. By configuring in this way, the retaining force between the rubber inner layer and the tube connecting portion and the detent force between the connector and the pipe body via the rubber inner layer should be sufficiently large. Can do. Moreover, it becomes possible to seal between the tube connection part of a connector and the insertion end part of a pipe body over a sufficiently long range.

  The laminated structure of the piping tube preferably includes a resin barrier layer so that the piping tube has permeation resistance to the internal fluid. And if this resin barrier layer is provided inside the rubber outer layer, and the tube connecting portion is fitted so as to cover the resin barrier layer and the rubber outer layer, the resin barrier layer and the tube connecting portion Due to the large engagement force between the two, the retaining force of the piping tube with respect to the tube connecting portion increases. For example, the resin barrier layer is directly placed on the tube connecting portion.

  Between the connector and the insertion end of the pipe body is a waterproof and dustproof annular seal member arranged on the other side in the axial direction from the rubber inner layer of the piping tube fitted in the inner periphery of the tube connection part If sealed, it is possible to effectively prevent foreign matter from entering between the rubber inner layer of the piping tube and the pipe body.

  As described above, when the pipe connection structure of the present invention is used, an effective pipe structure can be configured using a rubber tube.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a perspective view showing a pipe connection structure according to the present invention, FIG. 2 is a perspective view of a quick connector used in the pipe connection structure, and FIG. 3 is a cross-sectional view of the quick connector. This pipe connection structure is used for a gasoline fuel pipe of an automobile, more specifically, a filler pipe between a fuel filler port and a fuel tank.

  The pipe connection structure 1 includes a resin quick connector 3, a rubber filler hose (rubber pipe tube or rubber tube) 5 fitted on one side of the quick connector 3 in the axial direction, and a quick connector 3. And a metal pipe body 7 which is relatively inserted from the other side in the axial direction and protrudes from the vehicle body side or the fuel tank.

  The quick connector 3 includes a cylindrical connector housing 9 and a substantially annular retainer 11. The connector housing 9 is formed of glass fiber reinforced polyamide (PA + GF) as a raw material, and is integrally composed of a cylindrical tube connecting portion 13 on one axial side and a substantially cylindrical retainer holding portion 15 on the other axial side. And has a through hole 17 penetrating from one axial end to the other axial end. The tube connecting portion 13 has an axially one side portion 19 having a right-angled triangular section whose outer peripheral surface gradually increases in diameter toward the other side in the axial direction, and a substantially simple cylinder on the other side in the axial direction of the one side portion 19 in the axial direction. Are formed on the outer peripheral surface extending in the shape of a square-shaped retaining annular projection 21 having a rectangular cross section and two retaining annular projecting portions 23, 23 having a right-angled triangular section expanding in the axial direction. The other side portion 25 in the axial direction is formed with an interval in the axial direction sequentially from one side toward the other side in the axial direction, and a rubber tube or a rubber filler hose 5 is provided on the outer periphery or the outer peripheral surface. Tightly fitted and connected. An axially outer circumferential surface 27 (between the axially one side 19 and the retaining annular protruding portion 21) of the other axial side 25 is formed as a small or deep annular groove. 27 is fitted with a sealing O-ring 29 for sealing between the tube connecting portion 13 and the rubber tube 5 (see particularly FIG. 3).

  The inner peripheral surface of the tube connecting portion 13 is formed of a large diameter portion 31 on one side in the axial direction and a small diameter portion 33 on the other side in the axial direction, and the axial length of the large diameter portion 31 is that of the small diameter portion 33. It is longer than the axial length and is approximately 70% of the axial length of the tube connecting portion 13. An annular seal groove 35 is formed in the small diameter portion 33, and an O-ring 37 is fitted in the seal groove 35. The O-ring 37 includes fluorine rubber (FKM), acrylonitrile butadiene rubber (NBR), a blend of NBR and polyvinyl chloride (NBR + PVC), fluorosilicone rubber (FVMQ), ethylene / propylene / diene polymer rubber (EPDM) or An elastic material having waterproof and dustproof properties such as thermoplastic olefin (TPO) can be used.

  The substantially cylindrical retainer holding portion 15 is formed with engaging windows 39, 39 having the same structure so as to face the radially symmetric position, and each outer peripheral surface between the engaging windows 39, 39 has a radial direction. Flat portions 41, 41 having the same shape are provided so as to be symmetrically formed, and the flat portion 41 is formed over the entire axial length of the retainer holding portion 15, and is approximately 3 minutes of the outer diameter of the retainer holding portion 15. 1 width (length in the circumferential direction). On the one side in the axial direction of each flat portion 41, two identically shaped protrusions 43, 43 are formed in parallel with each other so as to extend in the circumferential direction with a slight gap in the axial direction. The ridge 43 extends over the entire width of the flat portion 41. A checker (not shown) for confirming the connection state between the pipe body 7 and the quick connector 3 is attached between the pair of protrusions 43 and 43.

  On the other side in the axial direction of each flat portion 41, a bulging portion 45 having the same shape is formed in the middle in the width direction, and this bulging portion 45 has the same protruding height as the ridge 43. Thus, the flat portion 41 extends in the axial direction from the other axial end until it is connected to the protrusion 43 on the other axial side.

  A retainer 11 made of PA is fitted in the retainer holding portion 15, and the retainer 11 is relatively flexible and formed so as to be elastically deformable. The retainer 11 has a relatively large deformation between both ends in the circumferential direction, in which a pair of engaging claws 47 and 47 having the same shape projecting radially outward are formed at the radially symmetrical position of the other axial end. The main body 49 has a C-shaped (substantially annular) cross section provided with a clearance for use, and the inner surface of the main body 49 is reduced in diameter toward one side in the axial direction except for a portion facing the deformation clearance. It is formed in a state. Reference numeral 51 denotes two notch-shaped recesses of the same shape formed on the one side in the axial direction of the main body portion 49 so as to be arranged in the circumferential direction or the width direction via a thin segment piece 53. These show the engagement convex part (it extends short in the axial direction) of the cross section square shape (rectangular shape) provided in the outer surface of the main-body part 49 part facing the clearance gap for a deformation | transformation.

  At the other axial end of the main body 49 of the retainer 11, a pair of operating arms 57, 57 extending from the position corresponding to the engaging claws 47, 47 incline radially outward toward the other axial side. The operation end portions 59 are integrally provided, and an operation end portion 59 protruding outward in the radial direction is formed at the other axial end portion of each operation arm 57. Engagement slits 61, 61 extending in the circumferential direction are also formed on one side in the axial direction of the main body 49 so as to face each other. The retainer 11 having such a configuration has an engagement claw 47 as a retainer holding part. 15 enters the engagement window 39 and becomes engaged or engageable with the other axial end 63 of the engagement window 39, and the operation end portions 59, 59 are connected to the other axial end portion of the retainer holding portion 15. Pushed into the retainer holding portion 15 from the other axial end opening so as to be engaged with the pair of receiving recesses 65, 65 formed corresponding to the engagement windows 39, 39. It has been. An accommodation recess 65 is formed at the other axial end of the retainer holding portion 15, and the operation end 59 of the operation arm 57 is accommodated in the accommodation recess 65, and the operation end 59 is arranged on the outer periphery of the retainer holding portion 15. By not projecting greatly from the surface, an external force is not easily applied to the operation end portion 59, and thus the retainer 11. The inner surfaces 67 and 67 of the retainer 11 facing each other, which extend from the operation arms 57 and 57 to the engagement slits 61 and 61, respectively, have a substantially tapered shape in the center or in the central axis direction toward one side in the axial direction. Inclined.

  On the inner peripheral surface of the retainer holding portion 15, a rectangular cross section (rectangular shape) extending from the other axial end to the one axial end of the bulging portion 45 along the bulging portion 45 at each bulging portion 45 position. ), And the cross-sectional shape of the engagement concave portion 69 is substantially the same as the cross-sectional shape of the retainer engagement convex portion 55 except for the other end portion in the axial direction. When the retainer 11 is fitted to the retainer holding portion 15, the engaging convex portion 55 is inserted and fitted into the engaging concave portion 69 or one axial side of the engaging concave portion 69. (The other end in the axial direction of the engaging recess 69 is formed in a larger cross-sectional shape than the engaging protrusion 55 to form an introduction guide portion). In addition, at one end in the axial direction of the inner peripheral surface of the retainer holding portion 15, two anti-rotation protrusions 71, 71 having the same shape protruding thinly inward in the radial direction are provided, and the anti-rotation protrusion 71 is a retainer. 11 is formed in substantially the same shape as the notch-shaped recess 51, and each rotation projection 71 is fitted in the notch-shaped recess 51 when the retainer 11 is fitted to the retainer holding portion 15. And is engaged with the notch-shaped recess 51 in the circumferential direction. In addition, even if the retainer 11 is rotated 180 degrees from the state shown in FIG. 1, the anti-rotation protrusions 71 and 71 are set at a pair in a radially symmetrical position so that the retainer 11 can be similarly fitted into the retainer holding portion 15. Is formed. In the illustrated example, the cross-sectional shape of the engaging concave portion 69 and the cross-sectional shape of the engaging convex portion 55 are the same, but the engaging concave portion 69 and the engaging convex portion 55 are not necessarily in the same cross-section. The engagement recess 69 and the engagement protrusion 55 can be formed with various cross-sectional shapes that can restrict the movement of the retainer 11 in the circumferential direction, or in the circumferential direction and the radial direction.

  FIG. 4 is a cross-sectional view of the end of the rubber tube or rubber filler hose 5.

  The rubber tube 5 has a laminated structure in which a resin barrier layer 77 is interposed between the rubber inner layer 73 and the rubber outer layer 75, and the adhesive strength between the layers exceeds 10 N / 25 mm. Are firmly bonded to each other. In the sample in which the adhesion strength was measured, the base material was destroyed before the layers were separated. At the end of the rubber tube 5, the rubber inner layer 73 and the resin barrier layer 77 are separated from each other in a non-adhered state, and the resin barrier layer 77 and the rubber outer layer 75 are separated from the rubber inner layer 73. It extends long outside. The length from the start end 79 of the non-bonded state between the rubber inner layer 73 and the resin barrier layer 77 to the outer ends of the resin barrier layer 77 and the rubber outer layer 75 is the outer periphery of the tube connector 13 of the quick connector 3. The length from the non-adhered start end 79 to the outer end of the rubber inner layer 73 is substantially equal to the axial length of the large-diameter portion 31 of the tube connecting portion 13. . In order to form such an end structure of the rubber tube 5, a hollow cylindrical spacer (not shown) is attached to the end of the rubber tube 5 prior to vulcanization after the rubber tube 5 is molded. Is inserted between the rubber inner layer 73 and the resin barrier layer 77, and the rubber tube 5 is vulcanized in a state in which the spacer is inserted. Just cut it.

  As the material for the rubber inner layer 73, NBR (acrylonitrile amount of 30% by mass or more with respect to the whole), NBR + PVC (acrylonitrile amount of 30% by mass or more with respect to the whole), FKM, hydrogenated NBR (H-NBR) or the like should be used. Can do. The thickness of the rubber inner layer 73 can be set to 1.0 to 2.5 mm. The material of the resin barrier layer 77 includes thermoplastic fluororesin (THV), polyvinylidene fluoride (PVDF), ethylene made of at least a terpolymer of vinylidene fluoride, hexafluoropropylene and tetrafluoroethylene. Tetrafluoroethylene copolymer (ETFE), polytetrafluoroethylene (PTFE), polychlorotrifluoroethylene (PCTFE), ethylene-vinyl alcohol (EVOH), polybutylene naphthalate (PBN), polybutylene terephthalate (PBT) Polyphenylene sulfide (PPS) can be used. The thickness of the resin barrier layer 77 can be set to 0.03 to 0.3 mm. Examples of the material of the rubber outer layer 75 include NBR, NBR + PVC (acrylonitrile amount of 30% by mass or more based on the whole), epichlorohydrin-ethylene oxide copolymer rubber (ECO), chlorosulfonated polyethylene rubber (CSM), acrylic rubber (ACM), A blend of NBR and ACM (NBR + ACM), ethylene-propylene-diene rubber (EPDM), a blend of NBR and EPDM (NBR + EPDM), butyl rubber (IIR), and the like can be used. The thickness of the rubber outer layer 75 can be set to 1.0 to 3.0 mm.

  The rubber inner layer 73 can be formed of a plurality of rubber layers instead of a single layer. The rubber outer layer 75 can also be formed of a plurality of rubber layers instead of a single layer.

  FIG. 5 is a diagram for explaining the configuration process of the pipe connection structure 1, showing the connection process between the quick connector and the rubber tube 5, and FIG. 6 is a cross-sectional view of the pipe connection structure 1.

  To configure the pipe connection structure 1, first, the rubber tube 5 is fitted into the tube connection portion 13 of the quick connector 3. The rubber tube 5 is fitted by relatively inserting the tube connecting portion 13 into the non-adhesive portion 81 between the resin barrier layer 77 and the rubber inner layer 73 (FIG. 5a). Here, the tips of the rubber outer layer 75 and the resin barrier layer 77 are flared (processed), and before the tips of the rubber outer layer 75 and the resin barrier layer 77 return to their original shapes, The tube connecting portion 13 is quickly inserted between the resin barrier layer 77 and the rubber inner layer 73. Then, the rubber outer layer 75 and the resin barrier layer 77 are tightly fitted to the outer periphery of the tube connecting portion 13 over the entire length, and the rubber inner layer 73 is inserted into the large diameter portion 31 of the tube connecting portion 13 over the entire length ( FIG. 5b). In this state, the non-adhered start end 79 is located near the tip of the tube connecting portion 13. For example, the outer peripheral surface of the rubber inner layer 73 is in contact with or pressed against the large-diameter portion 31. The resin barrier layer 77 is in direct contact with the outer periphery of the tube connecting portion 13, and the retaining annular protrusions 21 and 23 of the tube connecting portion 13 directly bite into the resin barrier layer 77. The tube connecting portion 13 and the rubber outer layer 75 side are firmly prevented from coming off. The outer diameter of the rubber inner layer 77 can be set to be the same as or substantially the same as the inner diameter of the large diameter portion 31. Further, as described above, the thickness of the rubber inner layer 73 can be set to 1.0 to 2.5 mm. Furthermore, the difference between the radius of the large diameter portion 31 and the radius of the small diameter portion 33 (large It is set to be slightly larger (for example, 20% larger) than the depth of the diameter portion 31. That is, the rubber inner layer 73 is formed so as to protrude inward from the small diameter portion 33.

  Next, the insertion end 83 of the pipe body 7 is relatively inserted into the quick connector 3 and the retainer 11 from the other side in the axial direction, and an annular engagement protrusion formed on the outer periphery of the insertion end 83 of the pipe body 7. The portion 85 is engaged (snapped) into the engagement slit 61 of the retainer 11. The pipe body 7 is connected to the quick connector 3 in a state of being prevented from coming off by engagement (fitting) of the annular engagement protrusion 85 with the engagement slit 61 (FIG. 6). Since the outer diameter of the insertion end portion 83 of the pipe body 7 is set to be the same or substantially the same as the inner diameter of the small diameter portion 33 of the tube connection portion 13, the inner diameter of the rubber inner layer 73 (the pipe body 7 is inserted). It is slightly larger than the inner diameter). In this state, the insertion end (tip) of the insertion end 83 of the pipe body 7 has reached the vicinity of one end (tip) in the axial direction of the tube connecting portion 13, and the insertion end 83 is inside the large-diameter portion 31. The rubber inner layer 73 inserted into the is compressed by being sandwiched between the large diameter portion 31. Therefore, the tube connecting portion 13 and the rubber inner layer 73 are firmly prevented from coming off. Further, the space between the insertion end 83 of the pipe body 7 and the large diameter portion 31 of the tube connecting portion 13 is well sealed by the compressed rubber inner layer 73. The O-ring 27 on the outer periphery of the tube connecting portion 13 seals between the tube connecting portion 13 and the resin barrier layer 77, and the O-ring 37 of the small diameter portion 35 is connected to the insertion end portion 83 and the small diameter portion of the pipe body 7. 33 is sealed.

  As described above, the pipe connection structure of the present invention is used for filler pipes of automobiles, for example, and achieves reduction of pipe costs.

It is a perspective view which shows the piping connection structure which concerns on this invention. It is a perspective view of a quick connector used in a pipe connection structure. It is sectional drawing of a quick connector. It is sectional drawing of the edge part of a rubber tube. It is a figure explaining the composition process of piping connection structure, and is a figure showing the connection process of a quick connector and a rubber tube. It is sectional drawing of a piping connection structure. It is a figure which shows the assembly process of the conventional connector. It is a figure which shows the assembly | attachment process of the conventional connector and piping tube.

Explanation of symbols

1 Piping connection structure 3 Quick connector 5 Rubber tube (Piping tube)
7 Pipe body 11 Retainer (Retainer means)
13 Tube connection portion 15 Retainer holding portion 73 Rubber inner layer 75 Rubber outer layer 77 Resin barrier layer 83 Insertion end

Claims (4)

A tubular tube connecting portion is formed on one side in the axial direction, a retainer means is provided on the other side in the axial direction, a piping tube connected to the tube connecting portion of the connector, and the connector in the axial direction. A pipe body having an insertion end relatively inserted from the other side and retained by the retainer means, and a pipe connection structure comprising:
The piping tube is a rubber tube having a laminated structure having a rubber inner layer and a rubber outer layer laminated on the outer side of the rubber inner layer, and the rubber inner layer is disposed inside the tube connecting portion. Fitted to the circumference, and the rubber outer layer is connected to the tube connection part in a state of tightly covering the outer circumference of the tube connection part,
The insertion end portion of the pipe body is inserted into the connector so as to extend into the tube connection portion, and is sandwiched so as to compress the rubber inner layer with the tube connection portion. Piping connection structure. The axial length of the rubber inner layer of the piping tube fitted in the inner periphery of the tube connecting portion is more than half of the axial length of the tube connecting portion. Item 1. The pipe connection structure according to Item 1. The laminated structure of the piping tube has a resin barrier layer inside the rubber outer layer, and the resin barrier layer and the rubber outer layer are tightly covered on the outer periphery of the tube connecting portion. The pipe connection structure according to claim 1 or 2, wherein Between the connector and the insertion end of the pipe body, on the other side in the axial direction than the rubber inner layer of the piping tube fitted in the inner periphery of the tube connecting portion, waterproof and dustproof. The pipe connection structure according to claim 1, wherein an annular seal member is disposed.

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