Joint pipe and method for manufacturing joint pipe

Abstract

This joint pipe comprises: a bellows pipe having a repeated structure of mountain and valley folds; an annular groove formed on an inner peripheral wall of the bellows pipe; and an O-ring that is fitted to the annular groove and seals fluid flowing from a cylindrical pipe material connected to the bellows pipe.

Description

Joint pipe and manufacturing method of joint pipe

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

[0002] Japanese Patent Publication No. 5224357 discloses a pipe fitting having a continuous spiral groove 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.

[0003] However, the method of connecting by screwing a corrugated pipe, as shown in Patent Publication No. 5224357, requires a lot of work to connect, and also requires a sealing sheet to be attached to the inner surface of the joint pipe to ensure sealing, which is troublesome.

[0004] 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.

[0005] The present disclosure facilitates connecting and sealing operations, allows axial movement of the tubing relative to the coupling pipe, and improves compliance with axial misalignment of the tubing.

[0006] A first aspect 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.

[0007] In the first aspect of the joint pipe, 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.

[0008] Furthermore, the connection can be completed simply by inserting the cylindrical pipe into the joint pipe, and the O-ring fitted in the annular groove ensures sealing.

[0009] A joint pipe of a 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.

[0010] 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.

[0011] 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.

[0012] In the joint pipe of the third aspect, multiple joint pipes are connected in series and form a flow path, so that the design freedom of the cooling circuit including the joint pipe is increased compared to a configuration in which a single joint pipe is set.

[0013] In the fourth aspect of the method for manufacturing a coupling tube, a softened tube is sandwiched between mold blocks having irregularities formed therein, and a vacuum is drawn around 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 an annular groove in the inner wall of the corrugated tube.

[0014] 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 having no parting line on its inner peripheral wall.

[0015] The method for manufacturing a joint pipe of the fifth aspect is the method for manufacturing a joint pipe of the fourth aspect, in which a long bellows pipe is formed and then cut to obtain a bellows pipe of the required length.

[0016] In the manufacturing method of the fifth aspect of the joint pipe, manufacturing costs can be reduced compared to a method in which corrugated pipes of the required length are manufactured one by one.

[0017] 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.

[0018] In the method for manufacturing a joint pipe according to the sixth aspect, predetermined flexibility and stretchability can be achieved.

[0019] 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.

[0020] 1A is a top perspective view of a cooling system including a coupling pipe of the present disclosure; FIG. 2B is a partial cross-sectional view of FIG. 1; FIG. 2C is a partial cross-sectional view of FIG. 3A; FIG. 3D is a cross-sectional view of a coupling pipe of the present disclosure; FIG. 3E is a cross-sectional view of a coupling pipe of the present disclosure; FIG. 3F is a cross-sectional view of a coupling pipe of the present disclosure; FIG. 3G is a cross-sectional view of a coupling pipe of the present disclosure; FIG. 3G is a cross-sectional view of a coupling pipe of the present disclosure; FIG. 3H is a cross-sectional view of a coupling pipe of the present disclosure;

[0021] 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.

[0022] 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 vertical 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 one another. While the above directions are used in the description of this specification, the orientation of the coupling pipe is not limited to these directions.

[0023] 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.

[0024] 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).

[0025] As shown in Fig. 3A, 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. A cooling coolant (i.e., 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.

[0026] As shown in Fig. 2, a portion of the cooling plate 14 has a box-shaped portion 14A at the front end in the depth direction. The box-shaped portion 14A is hollow. A cooling coolant is circulated inside the box-shaped portion 14A by a pump (not shown). As shown in Fig. 1, a plurality of coupling pipes 18 (described later) are arranged on both side surfaces of the box-shaped portion 14A in the width direction.

[0027] 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.

[0028] (Configuration of the coupling pipe) As shown in Figures 1 and 2, the coupling pipe 18 is arranged along the width direction and has a tubular shape with a center C. The coupling 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 coupling pipes 18 are connected in series along the center C (e.g., in the width direction). The coupling pipe 18 has a bellows tube 20, an annular groove 40, and an O-ring 60.

[0029] <Corrugated Tube> As shown in FIG. 1, the corrugated tube 20 is a bellows-shaped tube extending in the width direction and centered at C. Specifically, in FIG. 4, the corrugated tube 20 has a structure in which mountain folds and valley folds are repeated in the depth direction. More specifically, the corrugated tube 20 has a central portion MD with regularly repeated mountain folds and valley folds, and end portions EG in which the mountain folds and valley folds are irregular compared to the central portion MD. The corrugated tube 20 is stretchable in the width direction. In this embodiment, the corrugated 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. Furthermore, all of the junctions between the mountain folds and valley folds are inclined.

[0030] Furthermore, tapered portions 24A that expand radially from the valley fold portions 24 are formed at end portions EG of the bellows tube 20 in the width direction. The open ends of the tapered portions 24A serve as insertion openings 22, which constitute both ends of the bellows tube 20. In the bellows tube 20, one insertion opening 22 can be offset in the depth direction (i.e., axially misaligned) 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.

[0031] The inner diameter of the bellows tube 20, more specifically, the inner diameter DV of the valley-folded portion of the bellows tube 20 (see FIG. 4 ), is formed to be larger than the outer diameter of the pipe 16, as shown in FIG. 3(B) . The bellows tube 20 is connected to the outer periphery of the pipe 16.

[0032] <Annular Groove> As shown in Figure 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. Furthermore, 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.

[0033] The bottom 40A of the annular groove 40 forms a cylindrical surface. Both side surfaces of the annular groove 40 in the width direction 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.

[0034] <O-ring> 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.

[0035] The inner diameter DO of the O-ring 60 is smaller than the outer diameter of the pipe 16. 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, expanding in diameter. 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 and the annular groove 40 in the width direction.

[0036] (Method of Manufacturing Joint Pipe) Next, a method of manufacturing the joint pipe 18 will be described. 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.

[0037] 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 band-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.

[0038] 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.

[0039] 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.

[0040] 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.

[0041] In the second process 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, a vacuum is drawn to the outer peripheral surface 82 of the tube 80 through a 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.

[0042] 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.

[0043] In the fourth step PH4, a cutter 94 is used to cut at a cutting position CL to form a long bellows tube 20. The long bellows tube 20 refers to a tube that includes a straight pipe portion 28 that is located on the opposite side of the tapered portion 24A from the bellows tube 20 and continues from the tapered portion 24A, as shown in Fig. 6(B) .

[0044] In the finishing process, as shown in Fig. 6A, the long corrugated tube 20 cut at the cutting position CL is cut to the required length. As shown in Fig. 6B or 6C, the long corrugated tube 20 is cut at a first forming position CL1 or a second forming position CL2 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.

[0045] Then, when an O-ring 60 is fitted into the annular groove 40, the joint pipe 18 is completed.

[0046] (Operation 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 the 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 cooling coolant (not shown) that flows in from the pipe 16 connected to the corrugated tube 20. Even if a manufacturing error occurs in the width direction of the pair of pipes 16 connected to the end portions EG of the coupling pipe 18, by configuring the coupling pipe 18 as a corrugated tube 20, it is possible to allow axial movement of the connected pipes 16. Even if one of the pair of pipes 16 is misaligned axially relative to the other, the corrugated tube 20 deforms so that one insertion port 22 is misaligned axially relative to the other insertion port 22, and therefore it is possible to accommodate the axial misalignment between the coupling pipe 18 and 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 locations with limited installation space.

[0047] 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 a 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.

[0048] 1, a plurality of joint pipes 18 in this embodiment are connected in series to form a flow path through which a cooling coolant flows. According to this configuration, a plurality of joint pipes 18 are connected in series to form a flow path, which increases the design freedom of the cooling circuit including the joint pipe 18 compared to a configuration in which a single joint pipe is used.

[0049] 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.

[0050] Furthermore, in the manufacturing method of the joint pipe 18 of this embodiment, a long corrugated pipe 20 is formed and then cut to a required length of the corrugated pipe 20. 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.

[0051] 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.

[0052] (Modifications) 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.

[0053] Although the bellows tube 20 has three mountain folds and four valley folds in the widthwise center portion MD and one mountain fold and one valley fold at each of 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.

[0054] Although the annular groove 40 has a rectangular shape in plan view, the shape is not limited to this. For example, the annular groove 40 may have an elliptical shape in plan view.

[0055] 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.

[0056] Although the coolant flows through a plurality of channels connected in series, this configuration is not essential. The channels may also carry, for example, fluids, liquids, powders, particles, or gases for other purposes.

[0057] In the manufacturing method of the coupling pipe 18, the long corrugated tube 20 is formed and then cut to the required length, 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.

[0058] In addition, 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 within a range that can achieve predetermined flexibility and stretchability.

[0059] The disclosure of Japanese Patent Application No. 2024-011997, filed on January 30, 2024, is incorporated herein by reference in its entirety. All documents, patent applications, and technical standards mentioned herein are incorporated herein by reference to the same extent as if each individual document, patent application, and technical standard was specifically and individually indicated to be incorporated by reference.

Claims

1. A coupling pipe comprising: a corrugated pipe having a repeated mountain fold and valley fold structure; an annular groove formed in the inner peripheral wall of the corrugated pipe; and an O-ring fitted to the annular groove to seal against fluid flowing in from a cylindrical pipe material connected to the corrugated pipe.

2. A coupling pipe as set forth in claim 1, wherein the valley folded portion of the insertion opening of the bellows pipe is expanded in the radial direction.

3. A coupling pipe according to claim 1, in which a plurality of the coupling pipes are connected in series as a flow path for a cooling coolant to flow.

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

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

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