JP2015102171A - Pipeline connection structure - Google Patents

Abstract

A pipe connection structure with improved durability by suppressing degradation due to hydrolysis.
A stopper portion 24 is formed on a cylindrical member 20 made of resin from the outer peripheral surface of the cylindrical member 20 radially outward. The stopper portion 24 has a stopper surface 24A against which the distal end surface of the tubular body 18 is abutted. Between the outer peripheral surface and the stopper surface 44A, there is formed a groove 26 that constitutes a non-contacting space 28 that makes the radially inner end of the distal end surface of the tubular body 18 non-contacting and communicates with the outside air. .
[Selection] Figure 2

Description

  The present invention relates to a pipe connection structure, and more particularly to a pipe connection structure for connecting pipes via a resin material.

  In recent years, for the purpose of ease of molding and weight reduction, a resin material is used as a connection member for a tube body such as a hose instead of a metal material (see, for example, Patent Document 1). However, the resin material is easily deteriorated as compared with the metal material, and there is a demand for a countermeasure in consideration of deterioration due to hydrolysis.

JP 2006-234129 A

  The present invention has been made in view of the above facts, and an object thereof is to obtain a pipe connection structure with improved durability in consideration of degradation due to hydrolysis.

  The pipe connection structure according to the first aspect of the present invention has a tubular shape, and is disposed on the outer side in the radial direction from the outer peripheral surface of the tubular member, and a resin tubular member having a fluid flow path formed in the tube. The tubular body formed between the outer peripheral surface of the tubular member and the stopper surface, and a stopper portion having a stopper surface against which the distal end surface of the tubular body externally attached to the tubular member is abutted And a separation portion that forms a non-contact space that communicates with the outside air while making the inner end portion in the radial direction of the distal end surface of the tip end surface non-contact with the stopper portion.

  In the pipe connection structure according to the first aspect, the tubular body is extrapolated to the outer periphery of the cylindrical member, and the distal end surface is abutted against and connected to the stopper surface of the stopper portion. And the radial direction inner end part and stopper part of the front-end | tip surface of a tubular body are made into non-contact because the non-contact space is formed. Therefore, the distal end surface of the tubular body (the radially inner end portion of the distal end surface of the tubular body) does not contact the boundary portion between the outer peripheral surface of the cylindrical member and the stopper portion where stress concentrates when an external force is applied to the tubular body. The non-contact space communicates with the outside air. Thereby, the said boundary part becomes difficult to receive the influence of the water which penetrates between the internal peripheral surface of a tubular body, and a cylindrical body, and can suppress degradation by hydrolysis.

  The pipe connection structure according to a second aspect of the present invention is characterized in that a plurality of the stopper portions are provided apart from each other on the outer periphery of the cylindrical member.

  According to the pipe connection structure according to the second aspect of the invention, since the plurality of stopper portions are provided apart from each other, the non-contact space can be easily communicated with the outside air.

  In the pipe connection structure according to a third aspect of the present invention, the stopper portion is formed as a convex portion protruding outward in the radial direction of the cylindrical member, and the concave portion is an outer peripheral surface of the cylindrical member at the root of the stopper portion. It is comprised as a groove | channel formed along.

  According to the pipe connection structure according to the invention of claim 3, by forming the convex portion protruding radially outward of the cylindrical member, by forming a groove along the outer peripheral surface of the cylindrical member at the base of the convex portion, The stopper portion and the separation portion can be easily formed.

  According to a fourth aspect of the present invention, in the pipe connection structure, the cylindrical member is formed to protrude from the piping surface of the piping target member, and the stopper portion is formed to protrude from the piping surface and is spaced from the outer peripheral surface of the cylindrical member. It is characterized by being.

  According to the pipe connection structure according to the fourth aspect of the present invention, when the cylindrical member is formed to protrude from the piping surface of the piping target member, the stopper portion is separated from the outer peripheral surface of the cylindrical member so as to be spaced apart from the outer peripheral surface of the cylindrical member. Protrusions are formed. Thereby, a separation | spacing part is formed between the outer peripheral surface of a cylinder member, and a stopper part, and a stopper part and a separation | spacing part can be formed easily.

  According to the pipe connection structure according to the first aspect, it is possible to improve the durability by suppressing degradation due to hydrolysis of the boundary portion between the outer peripheral surface of the cylindrical member where the stress is concentrated and the stopper portion.

  According to the pipe connection structure of the second aspect, the non-contact space can be communicated with the outside air with a simple configuration.

  According to the pipe connection structure according to the third aspect, the stopper portion and the separation portion can be configured simply.

  According to the pipe connection structure according to the fourth aspect, the stopper portion and the separation portion can be simplified.

It is a perspective view of the piping connection structure concerning a 1st embodiment. It is a judgment surface view of the pipe joint structure concerning a 1st embodiment. (A) shows a pipe body unconnected, and (B) shows a pipe body connected state. It is sectional drawing which shows the shape of the groove | channel of the modification of 1st Embodiment. It is a perspective view of the piping connection structure concerning a 2nd embodiment. It is a judgment surface figure of the piping joint structure concerning a 2nd embodiment, (A) shows a pipe body unconnected, and (B) shows a pipe body connected state. It is a perspective view of the piping connection structure concerning a 3rd embodiment. It is a judgment surface view of the piping joint structure concerning a 3rd embodiment, (A) shows a pipe body unconnected, and (B) shows a pipe body connected state. FIG. It is a side view of the pipe connection structure concerning a comparative example. It is a graph which shows the relationship between the time of nylon resin, and allowable stress.

[First embodiment]
A pipe connection structure according to a first embodiment of the present invention will be described with reference to FIGS. 1 and 2. The pipe connection structure 10 of this embodiment includes a cylindrical tube member 20. A cylinder axis direction of the cylinder member 20 is indicated by a one-dot chain line, and a symbol S is given. A fluid flow path R is formed in the cylinder of the cylinder member 20. A thick portion 22 is formed on the end 20 </ b> A side of the cylindrical member 20. The thick-walled portion 22 is continuously formed with a tapered shape that gradually increases in diameter from one end 20A and a tapered shape that gradually decreases in diameter from the maximum diameter portion of the thick-walled portion 22 so that the cross-sectional shape is triangular. ing. A tubular body 18 is connected to the tubular member 20. The tubular body 18 is extrapolated to the cylindrical member 20 from the one end 20A side.

  A stopper portion 24 is formed integrally with the tubular member 20 at an intermediate portion in the tubular axial direction S of the tubular member 20. The stopper portion 24 is formed as a convex portion that protrudes radially outward from the outer periphery of the tubular member 20, and the circumferential direction of the tubular member 20 of the tubular member 20 is formed as a longitudinal direction. The stopper portions 24 are formed at four locations on the same circumference of the intermediate portion of the cylindrical member 20 in the cylindrical axis direction S and spaced apart at equal intervals.

  As shown in FIGS. 2A and 2B, a groove 26 is formed as a separation portion on the radially inner side of the stopper portion 24 on the one end 20A side. The groove 26 has a rectangular cross section. Due to the groove 26, the radially inner end 18 </ b> A and the stopper 24 of the distal end surface of the connected pipe body 18 are not in contact with each other. Further, a non-contact space 28 is formed between the outer peripheral surface 20B of the cylindrical member 20 and the stopper surface 24A. The non-contact space 28 communicates with the outside air at both ends in the circumferential direction of the stopper portion 24.

  As shown in FIG. 2 (B), the outer end 18B radially outside the radially inner end 18A of the distal end surface of the tubular body 18 is a stopper surface 24A formed on the one end 20A side of the stopper 24. It is hit by. The stopper surface 24A is disposed substantially perpendicular to the outer peripheral surface 20B of the cylindrical member 20. The surface of the stopper portion 24 opposite to the stopper surface 24 </ b> A is an inclined surface 24 </ b> B that forms an obtuse angle with the outer periphery of the tubular member 20.

  The protruding length L1 of the stopper portion 24 from the outer peripheral surface 20B of the cylindrical member 20 is preferably longer than the thickness W of the tubular body 18.

  The other end side (the side opposite to the one end 20A) of the cylindrical member 20 can be formed in a configuration that can be connected to a flow path (not shown) of another member, such as a taper screw or a flange. The cylindrical member 20 can be used as a joint.

  Next, the function and effect of this embodiment will be described.

  When connecting the tubular body 18 to the tubular member 20, the tubular body 18 is extrapolated from the one end 20A side of the tubular member 20, and the outer end portion 18B of the tubular body 18 is abutted against the stopper surface 24A. Then, the fastening band 19 is applied to the stopper portion 24 side of the thick portion 22 to fix the tubular body 18 to the cylindrical member 20.

  The liquid is used in this state and flows through the flow path R of the tubular body 18 and the cylindrical member 20. It is considered that the deterioration of the inner peripheral surface 20C (inner wall constituting the flow path R) of the cylindrical member 20 due to hydrolysis proceeds with long-term use. Further, it is considered that the liquid infiltrates at the molecular level and the hydrolysis proceeds at a portion where the outer peripheral surface 20B of the cylindrical member 20 is in contact with the inner peripheral surface 18C of the tubular body 18. In FIG. 2 (B), the portion considered to be deteriorated by hydrolysis is shown by shading. Here, when an external force is applied to the tubular body 18 and a radial force is applied to the tubular member 20, the stress concentrates on the boundary portion 29 between the outer peripheral surface 20 </ b> B of the tubular member 20 and the stopper portion 24. In the present embodiment, since the non-contact space 28 is formed, the boundary portion 29 is not in contact with the inner end portion 18A and the inner peripheral surface 18C of the tubular body 18, and the progress of deterioration due to hydrolysis is suppressed. Yes. Therefore, damage to the tubular member 20 due to the external force acting on the pipe body 18 is suppressed, and the durability of the pipe connection structure 10 can be improved.

  In this embodiment, four stopper portions 24 are provided on the outer periphery of the cylindrical member 20, but the number of stopper portions may be 1 to 3, or 5 or more. Further, when a plurality of stopper portions are provided, it is not always necessary to be spaced apart from each other at equal intervals, but by separating them at equal intervals, the tube body can be abutted against the stopper surface in a balanced manner and stable connection can be achieved.

  The stopper portion may be annular so as to extend over the entire outer periphery of the cylindrical member 20. In this case, in order to communicate the groove 26 with the outside air, a through hole communicating with the groove 26 may be formed in the stopper portion.

  In this embodiment, the groove 26 has a rectangular cross section, but may have other shapes, for example, a semicircular groove 26A as shown in FIG. As shown, it may be a triangular groove 26B.

[Second Embodiment]
Next, a second embodiment of the pipe connection structure according to the present invention will be described. In the present embodiment, the same parts as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

  As shown in FIGS. 4 and 5, the pipe connection structure 12 of this embodiment includes a cylindrical member 30, a pipe target wall 32, and a stopper portion 34.

  The piping target wall 32 is configured by a part of a casing or an outer wall of a device to which an external piping such as a radiator is connected and fluid is supplied to the inside. The cylindrical member 30 has a cylindrical shape and is formed so as to protrude from the wall surface 32 </ b> A of the piping target wall 32. A fluid flow path R is formed in the cylinder of the cylinder member 30. The flow path R communicates with a pipe (not shown) inside the pipe target wall 32. In addition, a thick portion 22 is formed on the distal end 30 </ b> A side of the cylindrical member 30.

  A stopper portion 34 is integrally formed on the piping target wall 32 on the radially outer side on the proximal end side of the tubular member 30. Four stopper portions 34 are formed at equal intervals along the outer peripheral surface 30 </ b> B of the cylindrical member 30. The stopper portion 34 is formed so as to protrude from the wall surface 32A of the piping target wall 32, is spaced from the outer peripheral surface 30B of the cylindrical member 30, and a separation portion 36 is formed between the wall surface 32A, the stopper portion 34, and the outer peripheral surface 30B. Yes. Due to the separation portion 36, the inner end portion 18 </ b> A of the connected pipe body 18 and the stopper portion 34 are not in contact with each other. A flat stopper surface 34 </ b> A is formed at the tip of the stopper portion 34. A non-contact space 38 is formed in the separation portion 36.

  As shown in FIGS. 5A and 5B, the stopper surface 34 </ b> A is disposed substantially perpendicular to the outer peripheral surface 30 </ b> B of the cylindrical member 30. The outer end portion 18B of the tubular body 18 is abutted against the stopper surface 34A. The non-contact space 38 communicates with the outside air at both ends in the circumferential direction of the stopper portion 34.

  The cylindrical member 30, the piping target wall 32, and the stopper portion 34 are made of resin, and nylon (PA), polypropylene (PP), or the like can be used as the resin. In addition, the protruding length L2 of the stopper portion 34 from the outer peripheral surface 30B of the cylindrical member 30 is preferably longer than the thickness W of the tubular body 18.

  Next, the function and effect of this embodiment will be described.

  When connecting the tubular body 18 to the tubular member 30, the tubular body 18 is extrapolated from the distal end 30A side of the tubular member 30, and the outer end portion 18B of the tubular body 18 is stopped as shown in FIG. It strikes against surface 34A. And the fastening band 19 is given to the stopper part 34 side rather than the thick part 22, and the tubular body 18 is fixed to the cylinder member 30. FIG.

  Also in this embodiment, when used over a long period of time, the aging deterioration of the tubular member 30 and the piping target wall 32 proceeds, and in particular, contact with the inner peripheral surface 30C of the tubular member 30 and the inner peripheral surface 18C of the tubular body 18. It is considered that hydrolysis proceeds on the outer peripheral surface 30B. In FIG. 5 (B), the portion considered to be deteriorated by hydrolysis is shown by shading. It is the boundary portion 39 between the outer peripheral surface of the tubular member 30 and the piping target wall 32 that is concentrated when an external force is applied to the tubular body 18 and a radial force acts on the tubular member 30. In the present embodiment, the boundary portion 39 is not in contact with the inner end portion 18A and the inner peripheral surface 18C of the tubular body 18, and the progress of deterioration due to hydrolysis is suppressed. Therefore, damage to the cylindrical member 30 due to the external force acting on the tubular body 18 is suppressed, and durability can be improved.

  In the present embodiment, four stopper portions 34 are provided, but the number of stopper portions may be 1 to 3, or 5 or more. The stopper portion may be annular so as to extend over the entire outer periphery of the cylindrical member 30. When the stopper portion is formed in an annular shape over the entire outer periphery of the cylindrical member 30, a through hole is formed in the radial direction so that the non-contact space 38 communicates with the outside air.

[Third embodiment]
Next, a third embodiment of the pipe connection structure according to the present invention will be described. In the present embodiment, the same parts as those in the first and second embodiments are denoted by the same reference numerals, and detailed description thereof is omitted.

  As shown in FIG. 6, the pipe connection structure 14 of this embodiment includes a cylindrical member 40 and a large-diameter connection portion 42. The cylindrical member 40 has the same shape as the cylindrical member 30 of the second embodiment, and the thick portion 22 is formed on the one end 40A side. A large-diameter connection portion 42 is formed integrally with the tubular member 40 on the opposite side of the tubular member 40 from the thick portion 22 in the tubular axial direction S. The large-diameter connection portion 42 has a cylindrical shape larger in diameter than the cylindrical member 40, and a flow path R1 communicating with the flow path R is formed in the cylinder.

  Between the cylindrical member 40 and the large diameter connecting portion 42, an annular stepped wall surface 42A is formed. The step wall surface 42 </ b> A is disposed substantially perpendicular to the outer peripheral surface 40 </ b> B of the tubular member 40. A stopper 44 is formed on the step wall 42A. Four stopper portions 44 are formed at equal intervals along the outer periphery of the cylindrical member 40.

  The stopper portion 44 protrudes from the step wall surface 42A toward the one end 40A. The radially outer surface of the stopper portion 44 is flush with the outer peripheral surface 42 </ b> B of the large-diameter connection portion 42. The stopper portion 44 is spaced from the outer peripheral surface 40B of the tubular member 40, and a separation portion 46 is formed between the stepped wall surface 42A, the stopper portion 44, and the outer peripheral surface 40B. Due to the separation portion 46, the inner end portion 18 </ b> A of the connected tubular body 18 and the stopper portion 44 are not in contact with each other. A flat stopper surface 44 </ b> A is formed at the tip of the stopper portion 44. A non-contact space 48 is formed in the separation portion 46.

  As shown in FIGS. 7A and 7B, the stopper surface 44 </ b> A is disposed substantially perpendicular to the outer periphery of the cylindrical member 40. As shown in FIG. 7B, the outer end portion 18B of the tubular body 18 is abutted against the stopper surface 44A. The non-contact space 48 is communicated with the outside air at both circumferential ends of the stopper portion 44.

  The cylindrical member 40, the large-diameter connection portion 42, and the stopper portion 44 are made of resin, and nylon (PA), polypropylene (PP), or the like can be used as the resin. In addition, the protruding length L3 of the stopper portion 44 from the outer peripheral surface 40B of the tubular member 40 is preferably longer than the thickness S of the tubular body 18.

  Next, the function and effect of this embodiment will be described.

  When connecting the tubular body 18 to the tubular member 40, the tubular body 18 is extrapolated from the one end 40A side of the tubular member 40, and the outer end portion 18B of the tubular body 18 is abutted against the stopper surface 44A. Then, the fastening band 19 is provided on the stopper portion 44 side with respect to the thick portion 22 to fix the tubular body 18 to the tubular member 40.

  Also in this embodiment, when used over a long period of time, the aging of the cylindrical member 40 proceeds, and in particular, the inner peripheral surface 40C of the cylindrical member 40, the inner peripheral surface 42C of the large-diameter connection portion 42, and the cylindrical member 40 It is considered that hydrolysis of a portion of the outer peripheral surface 40B that is in contact with the inner peripheral surface 18C of the tubular body 18 proceeds. In FIG. 7 (B), the portion considered to be deteriorated by hydrolysis is shown by shading. It is a boundary portion 49 between the outer peripheral surface of the tubular member 40 and the large-diameter connecting portion 42 when an external force is applied to the tubular body 18 and a radial force acts on the tubular member 40. In the present embodiment, the boundary portion 49 is not in contact with the inner end 18A and the inner peripheral surface 18C of the tubular body 18, and the progress of deterioration due to hydrolysis is suppressed. Therefore, damage to the cylindrical member 40 due to the external force action on the tubular body 18 is suppressed, and durability can be improved.

In the present embodiment, four stopper portions 44 are provided, but the number of stopper portions may be 1 to 3, or 5 or more. The stopper portion may be annular so as to extend over the entire outer periphery of the cylindrical member 40. When the stopper portion is formed in an annular shape over the entire outer periphery of the cylindrical member 40, a through hole is formed in the radial direction so that the non-contact space 48 communicates with the outside air.
Further, in order to ensure ventilation of the non-contact space 48, a hole penetrating in the direction of the cylinder axis S may be formed in the step wall surface 42A corresponding to the non-contact space 48. In addition, you may form the said hole similarly in the non-contact space of 1st, 2nd embodiment.

  The pipe connection structure according to the first to third embodiments described above can be used for pipe connection in an engine room of an automobile. In particular, it can be suitably used for an inlet / outlet of a heat exchanger such as a radiator or an inlet / outlet of an engine for cooling water.

  The pipe connection structure 14 of 3rd Embodiment is used as an Example of this invention, and the pipe connection structure C shown in FIG. 8 is used as a comparative example. The pipe body was connected to the cylindrical member of the example and the comparative example, a predetermined external force was applied to the pipe body, and the stress was measured at a specific position of the cylindrical member.

  As shown in FIG. 8, the pipe connection structure C is different from the pipe connection structure 14 in that the stopper portion 44 is not provided. In the pipe connection structure C, the tip end 18 </ b> A of the tubular body 18 is abutted against the stepped wall surface 42 </ b> A of the large-diameter connection portion 42 instead of the stopper portion 44. Further, in the pipe connection structure C, the stepped wall surface 42A is arranged at a position corresponding to the stopper surface 44A in the cylinder axis direction S.

  In the pipe connection structure 14, the stress is measured at the boundary portion 49 and the position 47 corresponding to the stopper surface 44 </ b> A in the cylinder axial direction S of the outer peripheral surface 20 </ b> B (see FIG. 7B). In the connection structure C, measurement was performed at the boundary portion 43 between the outer peripheral surface 40B and the stepped wall surface 42A. When the stress at the boundary portion 43 of the comparative example is A, the stress at the boundary portion 49 of the embodiment is B, and the stress at the position 47 is C, the magnitude of the stress is B> A> C.

  FIG. 9 shows a graph showing the relationship between time (aging) and allowable stress for resin (nylon). The broken line I indicates deterioration of the resin (nylon) with heat (hereinafter, the broken line I is referred to as “thermal deterioration line I”), and the solid line II includes hydrolysis (due to liquid in the piping) in addition to heat. Deterioration with time (hereinafter, solid line II is referred to as “heat + hydrolysis deterioration line II”). Since the position 47 of the example and the boundary portion 43 of the comparative example are in contact with the inner end portion 18A of the pipe body 18, the resin life is obtained from the heat + hydrolysis degradation line II. On the other hand, since the boundary portion 49 of the embodiment is not in contact with the inner end portion 18 </ b> A of the tubular body 18, the resin life can be obtained from the thermal deterioration line I.

  The resin life is considered by applying the stresses A, B, and C obtained by the measurement to the graph of FIG. The resin life (deterioration time CT until the allowable stress becomes C in the heat + hydrolysis degradation line II) at the position 47 in the example is the resin life (heat + hydrolysis degradation line II in the boundary portion 43 of the comparative example). Thus, the degradation time AT until the allowable stress becomes A is about 3.5 times. This is because the stress when the external force is applied is small at the position 47 in the embodiment, and therefore the allowable stress may be small. In addition, regarding the boundary portion 49 of the embodiment, the heat deterioration line I does not decrease to B, and the deterioration time is considered to be longer than the position 47. Therefore, in the example and the comparative example, the resin life can be compared by the resin life at the position 47 and the boundary portion 43. As described above, the resin life of the example was 3.5 times that of the comparative example, and it was confirmed that the durability of the example was excellent.

10, 12, 14 Piping connection structure 18 Tubing body 18A Radial inner end 20B Outer peripheral surface 20 Cylindrical member 24 Stopper portion 24A Stopper surface 26 Groove (separating portion)
28 Non-contacting space 30B Outer peripheral surface 30 Tubular member 32 Piping object wall (piping object member)
32A Wall surface (pipe surface)
34 Stopper portion 34A Stopper surface 36 Separating portion 38 Non-contacting space 40B Outer peripheral surface 40 Cylindrical member 44 Stopper portion 44A Stopper surface 46 Separating portion 48 Non-contacting space R Channel

Claims (4)

A cylindrical member made of resin in which a fluid flow path is formed in the cylinder; and
A stopper portion having a stopper surface that is disposed radially outward from the outer peripheral surface of the cylindrical member and against which a distal end surface of a tubular body that is extrapolated to the cylindrical member is abutted;
A non-contact portion formed between the outer peripheral surface of the tubular member and the stopper surface and configured to make the radially inner end portion of the distal end surface of the tubular body extrapolated and the stopper portion non-contact and communicate with the outside air. A separation portion forming a contact space;
Piping connection structure with   The pipe connection structure according to claim 1, wherein a plurality of the stopper portions are provided apart from each other on the outer periphery of the cylindrical member. The stopper portion is formed as a convex portion protruding outward in the radial direction of the cylindrical member,
3. The pipe connection structure according to claim 1, wherein the separation portion is configured as a groove formed along an outer peripheral surface of the cylindrical member at a base of the stopper portion.   The tubular member is formed to protrude from a piping surface of a piping target member, and the stopper portion is formed to protrude from the piping surface and is disposed apart from the outer peripheral surface of the cylindrical member. The pipe connection structure according to claim 1 or 2.

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