Joint pipe and manufacturing method for joint pipe

Abstract

To allow axial movement of a pipe material relative to a joint pipe, and improve followability of axial deviation between the joint pipe and the pipe material, in a configuration in which the pipe material is connected to the joint pipe.SOLUTION: A joint pipe has: a bellows pipe having a repeated mountain-fold and valley-fold structure; an annular groove formed in an inner peripheral wall of the bellows pipe; and an O-ring that is mounted to the annular groove, and seals fluid flowing in from a cylindrical pipe material connected to the bellows pipe.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present disclosure relates to a coupling tube and a method for manufacturing the coupling tube. [Background technology]

[0002] Patent Document 1 discloses a pipe fitting having a spiral groove continuously formed on the inner surface and a method for manufacturing the pipe fitting, in which a corrugated pipe is screwed into the end of the pipe fitting to connect it. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 5224357 Summary of the Invention [Problem to be solved by the invention]

[0004] However, the method of connecting by screwing in a corrugated pipe requires a lot of work, and in order to ensure a seal, it is necessary to attach a sealing sheet to the inner surface of the joint pipe, which is also troublesome.

[0005] Furthermore, in a pipe joint having a spiral groove, there is room for improvement in terms of tolerance for axial movement of the corrugated pipe (pipe body) connected to the pipe joint and in terms of ability to follow axial misalignment.

[0006] An object of the present disclosure is to facilitate connecting and sealing operations, allow axial movement of the tubing relative to the coupling pipe, and improve compliance with axial misalignment of the tubing. [Means for solving the problem]

[0007] A first embodiment of the coupling tube of the present disclosure includes a corrugated tube having a repeated mountain fold and valley fold structure, an annular groove formed in the inner peripheral wall of the corrugated tube, and an O-ring that is fitted into the annular groove and seals against fluid flowing in from a cylindrical tubing material connected to the corrugated tube.

[0008] In the joint pipe of the first aspect, by configuring the joint pipe as a bellows pipe, it is possible to allow axial movement of the connected pipe material and also to follow axial misalignment between the joint pipe and the pipe material.

[0009] Furthermore, the connection can be completed simply by inserting the cylindrical pipe into the joint pipe, and the O-ring installed in the annular groove ensures sealing.

[0010] The joint pipe of the second aspect is the joint pipe of the first aspect, in which the valley-folded portion of the insertion opening of the bellows tube expands in the radial direction.

[0011] In the second embodiment of the joint pipe, by expanding the valley fold portion of the insertion port of the bellows tube in the radial direction, the expanded portion becomes an inclined guide surface, making it easier to connect the pipe material to the joint pipe and easier to install the O-ring inside the joint pipe.

[0012] The joint pipe of the third aspect is the joint pipe of the first or second aspect, and a plurality of joint pipes are connected in series as a flow path through which a coolant for cooling flows.

[0013] In the third embodiment of the joint pipe, multiple joint pipes are connected in series and form a flow path, which increases the design freedom of the cooling circuit including the joint pipe compared to a configuration in which a single joint pipe is set.

[0014] The fourth aspect of the method for manufacturing a coupling tube involves clamping a softened tube on both sides between mold blocks having irregularities formed therein, and drawing a vacuum on the outer surface of the tube through air holes formed in the mold blocks to form a corrugated tube having a repeated mountain fold and valley fold structure and an annular groove in the inner wall of the corrugated tube.

[0015] In the fourth embodiment of the method for manufacturing a joint pipe, a softened tube is molded in a mold block having irregularities formed therein, thereby making it possible to manufacture a joint pipe that has no parting line on its inner peripheral wall.

[0016] A fifth embodiment of the method for manufacturing a joint pipe is the fourth embodiment of the method for manufacturing a joint pipe, in which a long bellows pipe is formed and then cut to obtain a bellows pipe of the required length.

[0017] In the fifth aspect of the manufacturing method for a joint pipe, manufacturing costs can be reduced compared to a method in which corrugated pipes of the required length are manufactured one by one.

[0018] A sixth aspect of the method for manufacturing a joint pipe is the method for manufacturing a joint pipe of the fourth or fifth aspect, wherein the tube is made of resin.

[0019] In the sixth aspect of the method for manufacturing a connector pipe, predetermined flexibility and stretchability can be achieved. [Effects of the Invention]

[0020] According to the present disclosure, connection and sealing operations are facilitated, axial movement of the pipe material relative to the coupling pipe is permitted, and axial misalignment of the pipe material can be accommodated. [Brief explanation of the drawings]

[0021] [Figure 1] FIG. 1 is a top perspective view of a cooling system including a coupling tube of the present disclosure. [Figure 2] FIG. 2 is a partial cross-sectional view of FIG. [Figure 3] 3A is a plan view of FIG. 1, and FIG. 3B is a partial cross-sectional view of FIG. 3A. [Figure 4] FIG. 1 is a cross-sectional view of a coupling tube of the present disclosure. [Figure 5] FIG. 2 is a cross-sectional plan view showing a manufacturing method of a joint pipe according to the present disclosure. [Figure 6] Figure 6(A) is a planar cross-section of a long corrugated tube cut at the cutting position, Figure 6(B) is a planar cross-section of a long corrugated tube cut at the first forming position, and Figure 6(C) is a planar cross-section of a long corrugated tube cut at the second forming position. DETAILED DESCRIPTION OF THE INVENTION

[0022] Hereinafter, embodiments for carrying out the present disclosure will be described with reference to the drawings. Components indicated by the same reference numerals in each drawing are the same or similar components. Duplicate descriptions and reference numerals in the embodiments described below may be omitted. Furthermore, all drawings used in the following description are schematic, and the dimensional relationships, ratios, etc. of each element shown in the drawings do not necessarily match those in reality. Furthermore, the dimensional relationships, ratios, etc. of each element between multiple drawings do not necessarily match.

[0023] An example of a coupling pipe according to this embodiment will be described with reference to the drawings. For convenience, the H direction refers to the up-down direction, the W direction refers to the width direction, and the D direction refers to the depth direction. The H direction, W direction, and D direction are perpendicular to each other. Although the above directions will be used in the description of this specification, the orientation of the coupling pipe is not limited to these directions.

[0024] (Cooling system configuration) 1, the cooling system 10 includes a battery pack 12, a cooling plate 14, a pipe 16, and a joint pipe 18. The cooling system 10 cools the battery pack 12.

[0025] The battery packs 12 are cylindrical and arranged in a row in the depth direction and spaced apart in the width direction. The battery packs 12 supply power to, for example, electronic components (not shown).

[0026] As shown in Fig. 3(A), the cooling plate 14 is formed in a wave shape in a plan view, and multiple cooling plates 14 are arranged in the width direction. The cooling plate 14 is formed hollow, and a cooling coolant (cooling water) is circulated inside the cooling plate 14 by a pump (not shown). The cooling coolant is an example of a fluid. The cooling plate 14 dissipates heat from the battery pack 12 while in contact with the side surface of the battery pack 12. The cooling plate 14 is made of a metal with relatively high thermal conductivity, such as aluminum.

[0027] As shown in Fig. 2, a part of the cooling plate 14 has a box-shaped portion 14A at the end on the front side in the depth direction. The box-shaped portion 14A is hollow, and a cooling coolant is circulated inside the box-shaped portion 14A by a pump (not shown). As shown in Fig. 1, a plurality of joint pipes 18 (described later) are arranged on both side surfaces in the width direction of the box-shaped portion 14A.

[0028] As shown in FIG. 2, the pipes 16 are cylindrical and extend in pairs in opposite directions from both widthwise side surfaces of the box-shaped portion 14A. In other words, the pipes 16 are cantilevered by the box-shaped portion 14A. The pipes 16 are in communication with the interiors of the box-shaped portions 14A and function as flow paths for flowing cooling water to the multiple box-shaped portions 14A. The pipes 16 are arranged in the vertical center of each box-shaped portion 14A. The pipes 16 are an example of tubular materials. The pipes 16 in one box-shaped portion 14A and the pipes 16 in the other box-shaped portion 14A facing that one box-shaped portion 14A are arranged spaced apart from each other in the widthwise direction.

[0029] (Configuration of joint pipe) As shown in Figures 1 and 2, the joint pipe 18 is arranged along the width direction and has a tubular shape with its center at C. The joint pipe 18 connects a pair of pipes 16 that are spaced apart in the width direction and face each other. In this embodiment, as shown in Figure 1, a plurality of joint pipes 18 are connected in series along the center C (width direction). The joint pipe 18 has a bellows tube 20, an annular groove 40, and an O-ring 60.

[0030] <Bellox tube> As shown in FIG. 1, the bellows tube 20 is a bellows-shaped tube that extends in the width direction and has a center C. Specifically, in FIG. 4, the bellows tube 20 has a structure in which mountain folds and valley folds are repeated in the depth direction. In more detail, the bellows tube 20 has a central portion MD where mountain folds and valley folds are repeated regularly, and end portions EG where the mountain folds and valley folds are irregular compared to the central portion MD, and the bellows tube 20 is stretchable in the width direction. In this embodiment, the bellows tube 20 has three mountain folds and four valley folds in the central portion MD in the width direction, and one mountain fold and one valley fold each in the two end portions EG. The tops of all the mountain folds are flat along the width direction. In addition, all of the junctions between the mountain folds and the valley folds are inclined.

[0031] Furthermore, tapered portions 24A are formed at the end portions EG of the bellows tube 20 in the width direction, widening in the radial direction from the valley fold portions 24. The open ends of the tapered portions 24A serve as insertion openings 22, which constitute both end portions of the bellows tube 20. In the bellows tube 20, one insertion opening 22 can be offset (axially misaligned) in the depth direction relative to the other insertion opening 22. With the pipes 16 inserted through the insertion openings 22 at both ends, the bellows tube 20 separates the pipes 16 in the width direction.

[0032] The inner diameter of the bellows tube 20, more specifically, the inner diameter DV (see Figure 4) of the valley fold portion of the bellows tube 20, is formed to be larger than the outer diameter of the pipe 16, as shown in Figure 3 (B), and the bellows tube 20 is connected to the outer periphery of the pipe 16.

[0033] <Annular groove> As shown in FIG. 4 , the annular groove 40 is a groove formed on the inner circumferential wall 26 of the bellows tube 20 on the open end side, with its center at C. The annular groove 40 has a rectangular shape when viewed in plan view. Specifically, the annular groove 40 is formed in an end portion EG that is closer to the open end than the central portion MD of the bellows tube 20, and closer to the mountain-fold portion than the tapered portion 24A. In this embodiment, a pair of annular grooves 40 are formed in the bellows tube 20. The annular groove 40 has a depth that allows the center of an O-ring 60, which will be described later, to be accommodated therein.

[0034] The bottom 40A of the annular groove 40 forms a cylindrical surface, and both side surfaces in the width direction of the annular groove 40 face each other with a distance DI between them. The mountain folds on the outer peripheral surface located behind the bottom 40A of the annular groove 40 have a convex shape that is closer to the center C than the mountain folds in the central portion MD of the bellows tube 20. In other words, the three mountain folds in the central portion MD protrude radially more than the mountain folds in the end portions EG.

[0035] <Oリング> As shown in FIG. 4 , the O-ring 60 is an annular body with its center at C and is fitted into the annular groove 40. The O-ring 60 seals the cooling coolant flowing in from the pipe 16 while being pressed between the outer circumferential surface of the pipe 16 and the inner circumferential wall 26 of the bellows tube 20. The O-ring 60 is made of rubber. In this embodiment, the O-ring 60 is fitted into each of the multiple annular grooves 40.

[0036] The inner diameter DO of the O-ring 60 is formed to be smaller than the outer diameter of the pipe 16, and when the O-ring 60 is inserted around the outer periphery of the pipe 16, the inner and outer peripheries of the O-ring 60 elastically deform and expand. The inner diameter DO of the O-ring 60 is also smaller than the inner diameter DV of the valley-folded portion of the bellows tube 20. The thickness TH of the O-ring 60 in the width direction is smaller than the distance DI between both side surfaces of the annular groove 40 in the width direction. In other words, there is a gap between the O-ring 60 in the width direction of the annular groove 40.

[0037] (Method for manufacturing joint pipe) Next, we will explain the method of manufacturing the joint pipe 18. As shown in Fig. 5, the joint pipe 18 is manufactured by molding the outer circumferential surface 82 of a tube 80 with a plurality of mold blocks 90. The tube 80 is made of resin.

[0038] The mold blocks 90 have a plurality of recesses and protrusions and a plurality of air holes 92 formed on the molding surface that comes into contact with the tube 80 (described later), and are arranged in pairs facing each other on both sides in the depth direction. The plurality of recesses and protrusions are formed in advance on the mold blocks 90 at positions that correspond to the bellows tube 20 and the annular groove 40 in one joint pipe 18. The mold blocks 90 are connected in a strip-like manner in the width direction and transport the tube 80 in the transport direction R. In this embodiment, the plurality of mold blocks 90 form two endless tracks on both sides in the depth direction to transport the tube 80.

[0039] The method for manufacturing the joint pipe 18 includes a preparation step, a first step PH1, a second step PH2, a third step PH3, a fourth step PH4, and a finishing step.

[0040] In a preparation step (not shown), a tube 80 is prepared as the base material of the joint pipe 18. Specifically, resin softened by heating is extruded in a tubular shape from a nozzle (not shown) in the discharge direction EX to prepare the tube 80.

[0041] 5, in the first step PH1, the tube 80 is sandwiched between mold blocks 90. Specifically, the tube 80 is sandwiched between the mold blocks 90 from both sides in the depth direction.

[0042] In the second step PH2, the outer peripheral surface 82 of the tube 80 is suctioned through the air holes 92 to form the outer peripheral surface 82 of the tube 80. Specifically, the outer peripheral surface 82 of the tube 80 is evacuated through the plurality of air holes 92 to form the bellows tube 20 and the annular groove 40. In this embodiment, a vacuum is drawn through the air holes 92 at a plurality of positions VC for each pair of mold blocks 90.

[0043] In the third step PH3, the bellows tube 20 and the annular groove 40 are cooled to fix their shapes, and the mold block 90 is removed.

[0044] In a fourth step PH4, cutting is performed at a cutting position CL to form a long bellows tube 20. The long bellows tube 20 refers to a tube that is located on the opposite side of the tapered portion 24A from the bellows tube 20 and includes a straight pipe portion 28 that continues from the tapered portion 24A, as shown in FIG. 6(B).

[0045] In the finishing process, as shown in Figure 6(A), the long corrugated tube 20 cut at the cutting position CL is cut to the required length. As shown in Figure 6(B), the long corrugated tube 20 is cut at a first forming position CL1 (see Figure 6(B)) or a second forming position CL2 (see Figure 6(C)) to form the corrugated tube 20. Here, the first forming position CL1 is a midpoint in the width direction of the tapered portion 24A, and the second forming position CL2 is a connection position between the tapered portion 24A and the straight pipe portion 28.

[0046] Then, when an O-ring 60 is fitted into the annular groove 40, the joint pipe 18 is completed.

[0047] (Action and effect) The coupling pipe 18 of this embodiment includes a corrugated tube 20 having a repeated mountain fold and valley fold structure, an annular groove 40 formed in an inner peripheral wall 26 of the corrugated tube 20, and an O-ring 60 that is fitted into the annular groove 40 and seals the coolant (not shown) that flows in from a pipe 16 connected to the corrugated tube 20. Even if a manufacturing error occurs in the width direction of a pair of pipes 16 connected to end portions EG of the coupling pipe 18, by configuring the coupling pipe 18 as a corrugated tube 20, axial movement of the connected pipes 16 can be tolerated. Even if one of the pair of pipes 16 is misaligned axially with respect to the other, the corrugated tube 20 deforms so that the insertion port 22 of one pipe is misaligned axially with respect to the other insertion port 22, so that the coupling pipe 18 can also accommodate the axial misalignment between the pipe 16. Furthermore, with the joint pipe 18 of this embodiment, the connection work is completed simply by inserting the pipe 16 into the bellows tube 20 due to the binding force of the O-ring 60, and sealing is ensured by the O-ring attached to the annular groove 40. Furthermore, because well-known connectors are not used to connect the pipes 16 together, it can be applied to places where installation space is limited.

[0048] Furthermore, in the joint pipe 18 of this embodiment, the valley fold portion 24 of the insertion opening 22 of the bellows tube 20 is expanded in the radial direction by the tapered portion 24A. By expanding the valley fold portion 24 of the insertion opening 22 in the radial direction, the inner surface of the tapered portion 24A becomes an inclined guide surface, making it easier to connect the pipe 16 to the joint pipe 18 and also easier to fit the O-ring 60 into the joint pipe 18.

[0049] 1, a plurality of joint pipes 18 in this embodiment are connected in series as a flow path through which a cooling coolant flows. According to this configuration, a plurality of joint pipes 18 are connected in series and form a flow path, which increases the degree of freedom in designing the cooling circuit including the joint pipe 18 compared to a configuration in which a single joint pipe is used.

[0050] The method for manufacturing the joint pipe 18 of this embodiment involves clamping a softened tube 80 from both sides between mold blocks 90 having irregularities formed therein, and drawing a vacuum on the outer peripheral surface 82 of the tube 80 through air holes 92 to form the corrugated tube 20 and the annular groove 40. According to this configuration, by molding the softened tube 80 with the mold blocks 90 having irregularities formed therein, a joint pipe having no parting line on the inner peripheral wall 26 can be manufactured.

[0051] Furthermore, in the manufacturing method of the joint pipe 18 of this embodiment, a long corrugated pipe 20 is formed and then cut to obtain a corrugated pipe 20 of the required length. Specifically, by selecting the first forming position CL1 or the second forming position CL2 and cutting the long corrugated pipe 20, manufacturing costs can be reduced compared to a method of manufacturing corrugated pipes of the required length one by one.

[0052] In the method for manufacturing the joint pipe 18 of this embodiment, the tube is made of resin. This configuration makes it possible to achieve predetermined flexibility and stretchability.

[0053] (Variation) Although the present disclosure has been described in detail with respect to specific embodiments, it will be apparent to those skilled in the art that the present disclosure is not limited to the specific embodiments and that the present disclosure can take on various other embodiments within the scope of the present disclosure.

[0054] Although the bellows tube 20 has three mountain folds and four valley folds in the widthwise central portion MD and one mountain fold and one valley fold each in the two end portions EG, this is not limited to this. Furthermore, although the inner diameter of the valley folds of the bellows tube 20 is uniformly DV, this is not limited to this. In Fig. 4, it is sufficient that the inner diameter of at least the valley folds on both sides of the annular groove 40 in the widthwise direction is DV.

[0055] Although the annular groove 40 has a rectangular shape in planar cross section, the shape is not limited to this. For example, the annular groove 40 may have an elliptical shape in planar cross section.

[0056] In the joint pipe 18, the valley bent portion 24 of the insertion opening 22 of the bellows pipe 20 is expanded in the radial direction by the tapered portion 24A, but this configuration is not essential.

[0057] Although a plurality of coolant flow passages are connected in series in the above embodiment, this configuration is not essential. For example, other fluids, liquids, powders, particles, or gases may flow through the flow passages.

[0058] In the manufacturing method of the joint pipe 18, a long corrugated tube 20 is formed and then cut to obtain the required length of the corrugated tube 20, but this configuration is not essential. Also, in the above embodiment, both ends are cut at either the first forming position CL1 or the second forming position CL2, but this is not limited to this. One end of the long corrugated tube 20 may be cut at the first forming position CL1, and the other end may be cut at the second forming position CL2.

[0059] Furthermore, in the manufacturing method of the joint pipe 18, the tube 80 is made of resin, but this configuration is not essential. The material of the tube 80 can be freely changed as long as the desired flexibility and stretchability can be achieved. [Explanation of symbols]

[0060] 10 Cooling System 12 Battery pack 14 Cooling plate 14A Box-shaped part 16 Pipe (an example of a pipe material) 18 Joint pipe 20 Bellows 22 Insertion port 24A tapered section 26 Inner wall 28 Straight pipe section 40 Annular groove 60 O-rings 80 tubes 82 Outer surface 90 mold block 92 Air vent CL cutting position CL1 1st molding position CL2 2nd molding position

Claims

1. A bellows tube with a repeated mountain fold and valley fold structure, an annular groove formed on an inner peripheral wall of the bellows tube; an O-ring fitted in the annular groove to seal against fluid flowing in from a cylindrical tubing connected to the bellows tube; A joint pipe having:

2. 2. The coupling pipe according to claim 1, wherein a valley folded portion of the insertion opening of the bellows pipe is expanded in the radial direction.

3. 2. The coupling pipe according to claim 1, wherein a plurality of said coupling pipes are connected in series as a flow path through which a coolant for cooling flows.

4. A method for manufacturing a coupling tube, comprising: clamping a softened tube on both sides between mold blocks having irregularities formed therein; and drawing a vacuum on the outer surface of the tube through air holes formed in the mold blocks, thereby forming a corrugated tube having a repeated mountain fold and valley fold structure and forming an annular groove in the inner wall of the corrugated tube.

5. 5. The method for manufacturing a joint pipe according to claim 4, wherein after forming a long bellows pipe, the bellows pipe is cut to a required length.

6. 5. The method for manufacturing a joint pipe according to claim 4, wherein the tube is made of resin.

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