Method for producing hollow article and hollow article

Abstract

In this method for producing a hollow article according to the present disclosure, a hollow article that has a pair of main surfaces is produced. The hollow article comprises a pair of metallic plates that constitute the pair of main surfaces, a flow passage wall part, and a resin fixation part. The method for producing a hollow article according to the present disclosure comprises: a preparation step; forming a gap in which the pair of metallic plates face each other; and forming the resin fixation part in the gap by insert molding. A mold that is used in the insert molding comprises: a first surface that is in contact with one of the pair of metallic plates; a second surface that is in contact with the other of the pair of metallic plates; and at least one gate for pouring a molten resin composition, which is a raw material for the resin fixation part, into the mold. The gate is formed on at least one of the first surface and the second surface.

Description

Manufacturing method of hollow article and hollow article

[0001] The present invention relates to a method for manufacturing a hollow article and to a hollow article.

[0002] A central processing unit (CPU) installed in a computer or a secondary battery installed in an electric vehicle generates heat during operation. As a means for cooling such a heat generating body, various cooling devices using a cooling medium have been proposed.

[0003] Patent Document 1 discloses a cooling device 900. As shown in Fig. 12, the cooling device 900 includes a housing 910 and a component 920. The component 920 is attached to the housing 910. A flow path R910 (see Fig. 13) for circulating a refrigerant is arranged inside the housing 910.

[0004] As shown in FIG. 13 , the housing 910 has a metal portion 911, a metal portion 912, a resin portion 913, and a resin portion 914. The metal portion 911 is a flat plate-like member. The metal portion 912 is a plate-like member. The metal portion 912 has a plurality of protrusions C912 for forming a flow path R910. The resin portion 913 is bonded to each of the metal portion 911 and the metal portion 912. The resin portion 913 indirectly connects the metal portion 911 and the metal portion 912. The resin portion 913 forms a side surface S910 of the housing 910. The resin portion 914 is disposed between the metal portion 911 and the metal portion 912 to reinforce the housing 910. The resin portion 913 is molded by injection molding.

[0005] Patent Document 1: International Publication No. 2020 / 241314

[0006] However, if the gate through which the molten resin portion 913 is poured into the mold faces the protruding portion C912 of the metal portion 912 during injection molding of the resin portion 913 (for example, if the gate is a side gate), the protruding portion C912 of the metal portion 912 is likely to be directly subjected to the injection pressure in the direction of the arrow shown in FIG. 13 . This may cause the protruding portion C912 to deform and break. If the protruding portion C912 breaks, the molten resin portion 913 may enter the flow path R910. As a result, the yield of the cooling device 900 may decrease.

[0007] An object of one aspect of the present disclosure is to provide a method for manufacturing a hollow article and a hollow article that can suppress a decrease in yield.

[0008] The means for solving the above problems include the following embodiments. <1> A method for manufacturing a hollow article having a pair of main surfaces, the hollow article comprising: a pair of metal plates constituting the pair of main surfaces; a flow path wall portion sandwiched between the pair of metal plates; and a resin fixing portion fixing one of the pair of metal plates to the other of the pair of metal plates; an internal flow path for circulating a heat exchange medium is formed by at least one of the pair of metal plates and the flow path wall portion; the method for manufacturing the hollow article comprises: preparing the pair of metal plates and the flow path wall portion; sandwiching the flow path wall portion between the pair of metal plates to form a gap where the pair of metal plates face each other; and forming the resin fixing portion in the gap by insert molding; <2> The method for manufacturing a hollow article according to <1>, wherein the pair of metal plates have a plurality of positioning holes, and the mold has a plurality of fitting portions that fit into the positioning holes. <3> The method for manufacturing a hollow article according to <1> or <2>, wherein, in forming the resin fixing portion, the position of the gate includes a position outside the periphery of the pair of metal plates. <4> The method for manufacturing a hollow article according to <3>, wherein at least one of the pair of metal plates has a notch on its periphery at a position corresponding to the position of the gate. <5> The method for manufacturing a hollow article according to any one of <1> to <4>, wherein at least one of the pair of metal plates has at least one through hole, and a space that communicates with the through hole but does not communicate with the flow path wall portion is formed by at least one of the pair of metal plates and the flow path wall portion, and in forming the resin fixing portion, the position of the gate includes a position facing the through hole.<6> The method for manufacturing a hollow article according to any one of <1> to <5>, further comprising forming a concave-convex structure on a portion of each of the pair of metal plates that contacts the resin fixing portion, wherein forming the concave-convex structure is performed before forming the gap. <7> A hollow article having a pair of main surfaces, the hollow article comprising: a pair of metal plates that constitute the pair of main surfaces; a flow path wall portion sandwiched between the pair of metal plates; and a resin fixing portion that fixes one of the pair of metal plates to the other of the pair of metal plates, wherein an internal flow path for circulating a heat exchange medium is formed by at least one of the pair of metal plates and the flow path wall portion, and the resin fixing portion has at least one gate mark only on at least one of the pair of main surfaces. <8> The hollow article according to <7>, wherein the position of the gate mark includes a position outside the periphery of the pair of metal plates. <9> The hollow article according to <8>, wherein at least one of the pair of metal plates has a notch on its periphery at a position corresponding to the position of the gate mark. <10> The hollow article according to any one of <7> to <9>, wherein at least one of the pair of metal plates has at least one through hole, the position of the gate mark includes a position within the through hole, the resin fixing portion has a filling portion filled in a space that communicates with the through hole but does not communicate with the internal flow path, and the space is formed by at least one of the pair of metal plates and the flow path wall portion. <11> The hollow article according to any one of <7> to <10>, wherein each of the pair of metal plates has an uneven structure at a portion that comes into contact with the resin fixing portion.

[0009] According to one aspect of the present disclosure, a method for manufacturing a hollow article and a hollow article that can suppress a decrease in yield can be provided.

[0010] FIG. 1 is a perspective view showing the appearance of a hollow article according to a first embodiment of the present disclosure. FIG. 2 is a perspective view showing the appearance of a hollow article according to the first embodiment of the present disclosure. FIG. 3 is a cross-sectional view taken along line III-III of FIG. 1. FIG. 4 is a cross-sectional view taken along line IV-IV of FIG. 1. FIG. 5 is a diagram illustrating a method for manufacturing a hollow article according to the first embodiment of the present disclosure. FIG. 6 is a perspective view showing the appearance of a hollow article according to a second embodiment of the present disclosure. FIG. 7 is a cross-sectional view taken along line VIII-VIII of FIG. 6. FIG. 8 is a diagram illustrating a method for manufacturing a hollow article according to the second embodiment of the present disclosure. FIG. 9 is a perspective view showing the appearance of a hollow article according to a third embodiment of the present disclosure. FIG. 10 is a perspective view showing the appearance of a hollow article according to the third embodiment of the present disclosure. FIG. 11 is a cross-sectional view taken along line XII-XII of FIG. 9. FIG. 12 is a perspective view showing the appearance of a conventional hollow article. FIG. 13 is a cross-sectional view taken along line XI-XI of FIG. 12.

[0011] In this disclosure, a numerical range indicated using "to" indicates a range that includes the numerical values ​​before and after "to" as the minimum and maximum values, respectively. In the numerical ranges described in stages in this disclosure, the upper or lower limit value described in a certain numerical range may be replaced with the upper or lower limit value of another staged numerical range, or may be replaced with a value shown in an example. In this disclosure, when multiple substances corresponding to each component are present in the material, the amount of each component in the material means the total amount of the multiple substances present in the material, unless otherwise specified. When embodiments in this disclosure are described with reference to drawings, the configuration of the embodiment is not limited to the configuration shown in the drawings. The sizes of components in each drawing are conceptual, and the relative size relationships between components are not limited thereto. In the drawings, the same or equivalent parts are designated by the same reference symbols, and descriptions thereof will not be repeated.

[0012] (1) Manufacturing Method of Hollow Article The manufacturing method of a hollow article disclosed herein manufactures a hollow article having a pair of main surfaces. The hollow article includes a pair of metal plates, a flow path wall, and a resin fixing portion. The pair of metal plates constitute the pair of main surfaces. The flow path wall is sandwiched between the pair of metal plates. The resin fixing portion fixes one of the pair of metal plates to the other of the pair of metal plates. An internal flow path for circulating a heat exchange medium is formed by at least one of the pair of metal plates and the flow path wall. The manufacturing method of a hollow article disclosed herein includes preparing the pair of metal plates and the flow path wall (hereinafter also referred to as a "preparation process"); sandwiching the flow path wall between the pair of metal plates to form a gap where the pair of metal plates face each other (hereinafter also referred to as an "assembly process"); and forming the resin fixing portion in the gap by insert molding (hereinafter also referred to as an "insert molding process"). The mold used for the insert molding (hereinafter also referred to as a "mold") has a first surface, a second surface, and at least one gate. The first surface contacts one of the pair of metal plates. The second surface contacts the other of the pair of metal plates. At least one gate is used to pour a molten resin composition (hereinafter also referred to as "first resin composition"), which is the raw material of the resin fixing portion, into the mold. The gate is formed on at least one of the first surface and the second surface. The preparation process, assembly process, and insert molding process are performed in this order.

[0013] "Hollow article" refers to an article having an internal flow path inside. "Internal flow path" refers to a space for circulating a heat exchange medium. "Metal plate" refers to a plate-like object made of metal. "Gap" refers to a space for forming a resin fixing part.

[0014] The manufacturing method of a hollow article according to the present disclosure has the above-described configuration, and therefore can suppress a decrease in yield. This effect is presumably due to, but not limited to, the following reasons. In the present disclosure, the gate is formed on at least one of the first surface and the second surface. In other words, the gate and the flow path wall are not opposed to each other. Therefore, in the insert molding process, the flow path wall is less likely to be directly subjected to injection pressure. This makes the flow path wall less likely to break than when the gate and the flow path wall are opposed to each other. As a result, it is presumed that the manufacturing method of a hollow article according to the present disclosure can suppress a decrease in yield.

[0015] (1.1) Hollow Article The shape of the hollow article is not particularly limited as long as it has a pair of main surfaces, and may be appropriately selected depending on the application of the hollow article, etc. Examples of the shape of the hollow article include a rectangular parallelepiped, a cubic, and a cylindrical object.

[0016] The hollow article includes a pair of metal plates, a flow path wall portion, and a resin fixing portion. The pair of metal plates constitute a pair of main surfaces of the hollow article. The flow path wall portion is sandwiched between the pair of metal plates. The resin fixing portion fixes one of the pair of metal plates to the other of the pair of metal plates.

[0017] The flow path wall may be made of metal or resin. The pair of metal plates and the flow path wall may be separate bodies. When the flow path wall is made of metal, at least one of the pair of metal plates and the flow path wall may be an integrally molded metal product. Details of the hollow article will be described later.

[0018] Hereinafter, a metal flow path wall may be referred to as a "metal flow path wall," and a resin flow path wall may be referred to as a "resin flow path wall."

[0019] (1.2) Preparation Step The method for manufacturing a hollow article includes a preparation step.

[0020] In the preparation step, a pair of metal plates and a flow path wall portion are prepared.

[0021] The method for preparing the pair of metal plates is not particularly limited, and examples thereof include metal forming. Examples of metal forming include roll forming, die casting, cutting, rolling, press forming, and extrusion forming. The method for preparing the flow path wall portion is appropriately selected depending on the material of the flow path wall portion, etc. The method for preparing the metal flow path wall portion is not particularly limited, and examples thereof include metal forming. The method for preparing the resin flow path wall portion is not particularly limited, and examples thereof include resin forming. When at least one of the pair of metal plates and the flow path wall portion are an integrally molded metal product, the method for preparing the integrally molded metal product is not particularly limited, and examples thereof include metal forming.

[0022] (1.3) Assembly Process The method for manufacturing a hollow article includes an assembly process.

[0023] In the assembly process, the flow path wall portion is sandwiched between a pair of metal plates to form a gap where the pair of metal plates face each other, thereby obtaining an insert body.

[0024] The gap between the insert bodies may be formed, for example, around the entire periphery of the metal plate and each of the metal plates, or may be formed around a portion of the entire periphery of the metal plate and each of the metal plates. The method for forming the gap is not particularly limited. The assembly process may be performed outside the mold or inside the mold. When the pair of metal plates have a plurality of positioning holes and the mold has a plurality of fitting portions that fit into the positioning holes, the positioning holes of the pair of metal plates may be fitted into the fitting portions of the mold.

[0025] (1.4) Roughening Step Preferably, the method for manufacturing a hollow article further includes forming an uneven structure (hereinafter also referred to as a "roughening step") on the portion of each of the pair of metal plates that contacts the resin fixing portion (hereinafter also referred to as a "contact portion"). The roughening step is performed before the insert molding step is performed. The roughening step may be performed before the assembly step is performed, or may be performed after the assembly step is performed and before the insert molding step is performed.

[0026] By including the roughening step in the manufacturing method for the hollow article, a portion of the resin fixing portion penetrates into the recesses of the uneven structure of the metal plate during the insert molding step, thereby more strongly adhering the resin fixing portion to each of the pair of metal plates, resulting in a hollow article that maintains excellent airtightness for a long period of time.

[0027] The state of the concave-convex structure is not particularly limited as long as sufficient bonding strength (hereinafter also referred to as "bonding strength") between the metal plate and the resin fixing portion can be obtained. The average pore size of the recesses in the concave-convex structure is preferably 5 nm to 500 μm, more preferably 10 nm to 150 μm, and even more preferably 15 nm to 100 μm. The average pore depth of the recesses in the concave-convex structure is preferably 5 nm to 500 μm, more preferably 10 nm to 150 μm, and even more preferably 15 nm to 100 μm. When at least one of the average pore size or average pore depth of the recesses in the concave-convex structure is within the above numerical range, stronger bonding tends to be obtained. The average pore size and average pore depth of the recesses are measured according to JIS B0601-2001.

[0028] The method for forming the uneven structure is not particularly limited. Examples of the method for forming the uneven structure include a method using a laser as disclosed in Japanese Patent No. 4020957; a method using an inorganic base (e.g., NaOH, etc.) and an inorganic acid (e.g., HCl, HNO ３A method of immersing the surface of the housing in an aqueous solution of an acid-based etchant (preferably an inorganic acid, ferric ions, and cupric ions) and, if necessary, manganese ions, aluminum chloride hexahydrate, sodium chloride, etc., as disclosed in WO 2015-8847; a displacement crystallization method of etching with an aqueous acid-based etchant containing such as an aqueous solution of an acid-based etchant; a method of immersing the surface of the metal plate in an aqueous solution of one or more selected from hydrazine hydrate, ammonia, and a water-soluble amine compound, as disclosed in WO 2009 / 31632; a hot water treatment method as disclosed in JP 2008-162115 A; and blasting treatment, etc. The method of forming the uneven structure can be selected depending on the material of the surface that comes into contact with the resin fixing portion of the metal plate, the state of the desired uneven structure, etc.

[0029] The surface of the metal plate may be subjected to a treatment for adding functional groups in order to improve the bonding strength. The treatment for adding functional groups may be performed by various known methods.

[0030] (1.5) Insert Molding Process In the insert molding process, a resin fixing portion is formed in the gap by insert molding. Specifically, a molten first resin composition is filled into the gap of the insert body, and then cooled to solidify the molten first resin composition. The resin fixing portion surrounds the periphery of the pair of metal plates. This results in a hollow article.

[0031] Specifically, an injection molding machine is used for insert molding. The injection molding machine includes a mold, an injection device, and a mold clamping device. The injection device pours a melt of the first resin composition into the mold at a predetermined injection pressure. The mold clamping device clamps the mold with high pressure to prevent the mold from opening due to the filling pressure of the melt of the first resin composition.

[0032] In insert molding, first, a mold with an insert body placed inside is clamped. This forms a molding space for forming a resin fixing portion between the insert body and the injection molding mold. Next, the injection molding machine fills the molding space with a melt of the first resin composition at high pressure. Next, the melt of the first resin composition in the mold is cooled and solidified. This forms a resin fixing portion in the insert body. In other words, a hollow article according to the present disclosure is obtained.

[0033] (1.5.1) Mold The mold used for insert molding has a first surface, a second surface, and at least one gate. The first surface contacts one of a pair of metal plates. The second surface contacts the other of the pair of metal plates. The at least one gate is used to pour a melt of the first resin composition into the mold. The gate is formed on at least one of the first surface and the second surface.

[0034] The structure of the mold is not particularly limited, and may be a two-plate mold or a three-plate mold. A two-plate mold has a fixed-side mold plate and a movable-side mold plate. The fixed-side mold plate is fixed to the injection molding machine. The movable-side mold plate is movable relative to the fixed-side mold plate. A three-plate mold has a fixed-side mold plate, a movable-side mold plate, and a runner stripper plate. The runner stripper plate, fixed-side mold plate, and movable-side mold plate are stacked in this order.

[0035] The shape of the first surface of the mold is selected according to the shape of one of the main surfaces of the pair of metal plates. When one of the main surfaces of the pair of metal plates is flat, the shape of the first surface of the mold is flat. The shape of the second surface of the mold is selected according to the shape of the other main surface of the pair of metal plates. When the other main surface of the pair of metal plates is flat, the shape of the second surface of the mold is flat. The number of gates is not particularly limited and is selected appropriately according to the size of the hollow article, etc.

[0036] Preferably, the pair of metal plates have a plurality of positioning holes, and the mold has a plurality of fitting portions that fit into the positioning holes. This allows the pair of metal plates to be positioned at specific positions within the mold. As a result, the method for manufacturing a hollow article can further suppress a decrease in yield.

[0037] The dimensions of the positioning holes are not particularly limited and are appropriately selected depending on the size of the hollow article, etc. The dimensions are preferably 1.0 mm to 5.0 mm, and more preferably 2.0 mm to 3.0 mm.

[0038] The positions of each of the multiple positioning holes in the pair of metal plates and the positions of each of the multiple fitting portions in the mold may be selected appropriately depending on the shape of the pair of metal plates, etc. The shape of the positioning holes is not particularly limited and may be any known shape (e.g., round holes, pin holes, etc.). The shape of the fitting portions is not particularly limited as long as they fit into the positioning holes and may be any known shape (e.g., pins (protrusions)). The number of positioning holes in the pair of metal plates and the number of fitting portions in the mold each need only be at least two, and preferably three. The number of positioning holes in the pair of metal plates and the number of fitting portions in the mold may be the same or different.

[0039] In the insert molding process, the gate position preferably includes a position outside the periphery of the pair of metal plates. This allows a resin fixing portion to be formed that surrounds the periphery of the pair of metal plates. Furthermore, in the insert molding process, the flow path wall portion is less likely to be directly subjected to injection pressure. As a result, the manufacturing method of the hollow article disclosed herein can suppress a decrease in yield.

[0040] In the insert molding process, when the gate position includes a position outside the periphery of the pair of metal plates, at least one of the pair of metal plates preferably has a notch on its periphery at a position corresponding to the gate position. This allows the length (width) of the resin fixing portion along the main surface of the hollow article to be shorter than when at least one of the pair of metal plates does not have a notch. As a result, the manufacturing method of the hollow article disclosed herein can manufacture a more compact hollow article.

[0041] "A position on the periphery corresponding to the position of the gate" refers to a position on the periphery of a pair of metal plates near the position of the gate of the mold (i.e., a position surrounding the position of the gate) when the pair of metal plates are placed in the mold.

[0042] The number of notches may be the same as or different from the number of gates located outside the periphery of the pair of metal plates. The shape of the notches is not particularly limited, and examples thereof include an arc shape (e.g., semicircular), a triangle, a rectangle, a polygon, and an irregular shape. It is preferable that the notches in the pair of metal plates are formed so as to surround the gates of the mold when the pair of metal plates are placed in the mold.

[0043] The dimensions of the notch are not particularly limited and are appropriately selected depending on the size of the hollow article, etc. When the shape of the notch is arc-shaped, the value obtained by subtracting the diameter of the gate mark from the diameter of the arc is preferably 0.1 mm to 10 mm, and more preferably 0.5 mm to 5 mm.

[0044] At least one of the pair of metal plates has at least one through-hole, and a space (hereinafter also referred to as "internal space") that communicates with the through-hole but not with the flow path wall portion is formed by at least one of the pair of metal plates and the flow path wall portion. In forming the resin fixing portion (i.e., the insert molding process), it is preferable that the position of the gate includes a position facing the through-hole. This allows the internal space to be filled with a melt of the first resin composition, forming the resin fixing portion. In other words, the contact area between the pair of metal plates and the resin fixing portion is larger than when no internal space is formed. As a result, each of the pair of metal plates is more strongly fixed. Therefore, a hollow article with excellent airtightness can be obtained for a long period of time.

[0045] (2) Hollow Article The hollow article disclosed herein has a pair of main surfaces. The hollow article comprises a pair of metal plates, a flow path wall, and a resin fixing portion. The pair of metal plates constitute the pair of main surfaces of the hollow article. The flow path wall is sandwiched between the pair of metal plates. The resin fixing portion fixes one of the pair of metal plates to the other of the pair of metal plates. An internal flow path is formed by at least one of the pair of metal plates and the flow path wall. The internal flow path is used to circulate a heat exchange medium. The resin fixing portion has at least one gate mark on at least one of the pair of main surfaces. The gate mark may be a resin mark in a cold runner or a resin mark in a hot runner.

[0046] Because the hollow article of the present disclosure has the above-described configuration, the flow path wall is not directly subjected to the injection pressure during the insert molding process. Therefore, the flow path wall is less deformed than when the gate mark and the flow path wall face each other. As a result, the hollow article of the present disclosure has excellent airtightness over a long period of time.

[0047] (2.1) Metal Plate The metal plate constitutes a part of the wall portion that forms the internal flow path. The metal plate is a plate-like object. The shape of the metal plate can be, for example, a flat plate. The size of the metal plate is appropriately selected depending on the application of the hollow article.

[0048] Each of the pair of metal plates preferably has a concave-convex structure at the portion that contacts the resin fixing portion. This allows a portion of the resin fixing portion to fit into the recess of the concave-convex structure of the metal plate. As a result, the metal plate is more firmly bonded to the resin fixing portion. Therefore, the airtightness of the hollow article can be maintained for a longer period of time.

[0049] The uneven structure is formed by carrying out the roughening process described above. The state of the uneven structure is the same as the example of the state of the uneven structure in the roughening process described above. The surface of the metal plate may be subjected to a treatment to add the above-mentioned functional groups in order to improve the bonding strength.

[0050] The metal constituting the metal plate is not particularly limited, and examples thereof include iron, copper, nickel, gold, silver, platinum, cobalt, zinc, lead, tin, titanium, chromium, aluminum, magnesium, manganese, and alloys thereof (e.g., stainless steel, brass, phosphor bronze, etc.). From the viewpoint of thermal conductivity, the metal constituting the metal plate is preferably aluminum, an aluminum alloy, copper, or a copper alloy, and more preferably copper or a copper alloy. From the viewpoint of weight reduction and strength, the metal constituting the metal plate is preferably aluminum or an aluminum alloy. The metal constituting one of the pair of metal plates and the metal constituting the other of the pair of metal plates may be the same or different.

[0051] (2.2) Flow path wall The flow path wall constitutes a part of the wall that forms the internal flow path. The flow path wall is, for example, a cylindrical or plate-like object. An example of a flow path wall that is a plate-like object is a flow path wall having a plate and an annular wall for forming the internal flow path. The annular wall has a first main surface facing the metal plate and a second main surface opposite the first main surface. The annular wall protrudes from the second main surface of the plate. The annular wall is cylindrical. The shape and size of the flow path wall are selected appropriately depending on the application of the hollow article. Examples of materials for the flow path wall include resin and metal.

[0052] (2.2.1) Resin Flow Channel Walls Resin flow channel walls can reduce the weight of the hollow article compared to when metal flow channel walls are used, and can also improve the degree of freedom in designing the internal flow channels.

[0053] The resin flow path wall is a molded article made of a second resin composition. The resin flow path wall includes an injection-molded article or a press-molded article. The resin component of the second resin composition is not particularly limited, and examples thereof include thermoplastic resins (including elastomers) and thermosetting resins. Examples of thermoplastic resins (including elastomers) include polyolefin-based resins, polyvinyl chloride, polyvinylidene chloride, polystyrene-based resins, acrylonitrile-styrene copolymer (AS) resins, acrylonitrile-butadiene-styrene copolymer (ABS) resins, polyester-based resins, poly(meth)acrylic-based resins, polyvinyl alcohol, polycarbonate-based resins, polyamide-based resins, polyimide-based resins, polyether-based resins, polyacetal-based resins, fluorine-based resins, polysulfone-based resins, polyphenylene sulfide resins, and polyketone-based resins. Examples of thermosetting resins include phenolic resins, melamine resins, urea resins, polyurethane-based resins, epoxy resins, and unsaturated polyester resins. These resins may be used alone or in combination of two or more. From the viewpoint of moldability, the resin component of the second resin composition preferably contains a thermoplastic resin. The second resin composition may consist of a resin component. The second resin composition may contain at least one of a filler and a compounding agent, as necessary. Examples of fillers include fibers (e.g., glass fibers, carbon fibers, and cellulose fibers), carbon nanotubes (CNTs), graphene, carbon particles, clay, talc, silica, and minerals. These fillers may be used alone or in combination of two or more. Examples of compounding agents include heat stabilizers, antioxidants, pigments, weathering agents, flame retardants, plasticizers, dispersants, lubricants, mold release agents, and antistatic agents. These compounding agents may be used alone or in combination of two or more.

[0054] (2.2.2) Metal flow path wall The metal flow path wall has superior mechanical strength to the resin flow path wall. Therefore, for example, when a heat exchange medium circulates in the internal flow path, the pressure resistance of the hollow article against the internal pressure caused by the circulation of the heat exchange medium can be improved compared to when the flow path wall is a resin flow path wall.

[0055] The metal constituting the metal flow path wall portion is not particularly limited and may be the same as the metal exemplified as the metal constituting the metal plate. The metal constituting the metal flow path wall portion may be the same as or different from the metal constituting each of the pair of metal plates.

[0056] The metal flow path wall portion may be a separate body from each of the pair of metal plates. In this case, the method for fixing the metal flow path wall portion to at least one of the pair of metal plates is not particularly limited, and examples thereof include insert molding and a method using a known adhesive.

[0057] At least one of the pair of metal plates and the metal flow path wall portion may be an integrally molded metal product, including a rolled product, a die-cast product, a machined product, a rolled material, a pressed product, or an extruded material.

[0058] When the metal constituting the metal flow path wall and the metal constituting the metal plate are different metals, the hollow article preferably has an electrical insulating layer. The electrical insulating layer is interposed between the metal flow path wall and the metal plate. This makes it difficult for the different metals to come into electrical contact with each other. This makes it possible to suppress the occurrence of electrolytic corrosion between the different metals. As a result, the metal plate is less susceptible to corrosion. The electrical insulating layer is not particularly limited as long as it is a film having electrical insulation properties, and examples thereof include an adhesive layer, an insert bonding layer, and an elastomer packing.

[0059] (2.3) Resin fixing portion The resin fixing portion fixes one of the pair of metal plates to the other. The resin fixing portion has at least one gate mark on only at least one of the pair of main surfaces of the hollow article. The resin fixing portion is a fixing portion made of resin. The resin fixing portion surrounds the peripheries of the pair of metal plates.

[0060] The number and positions of the gate marks are the same as the number and positions of the gates of the mold described above. The number of gate marks is not particularly limited and is selected appropriately depending on the size of the hollow article, etc.

[0061] The gate marks are preferably positioned outside the peripheries of the pair of metal plates, which makes it less likely that the flow path walls will be directly subjected to injection pressure during insert molding of the resin fixing portion, thereby more reliably sealing the internal flow path.

[0062] When the gate mark position includes a position outside the periphery of the pair of metal plates, at least one of the pair of metal plates preferably has a notch at a position on its periphery corresponding to the gate mark position. This makes the length (width) of the resin fixing portion along the main surface of the hollow article shorter than when at least one of the pair of metal plates does not have a notch. As a result, the hollow article of the present disclosure is more compact.

[0063] The number of notches may be the same as or different from the number of gates located outside the periphery of the pair of metal plates. The shape of the notches is not particularly limited, and examples thereof include semicircular, triangular, rectangular, polygonal, and irregular shapes.

[0064] Preferably, at least one of the pair of metal plates has at least one through hole, the position of the gate mark includes a position within the through hole, and the resin fixing portion has a filling portion filled in a space (i.e., an internal space) that is connected to the through hole but not to the flow path wall portion. The space (i.e., the internal space) is formed by at least one of the pair of metal plates and the flow path wall portion. This results in a larger contact area between the pair of metal plates and the resin fixing portion than when the resin fixing portion does not have a filling portion. As a result, each of the pair of metal plates is more strongly fixed. Therefore, the hollow article disclosed herein has excellent airtightness over a long period of time.

[0065] The resin fixing portion is a molded body of the first resin composition. Examples of the resin component of the first resin composition include the same resins as those exemplified as the resin component of the second resin composition. The resin component of the first resin composition may be the same as or different from the resin component of the second resin composition. It is preferable that the resin component of the first resin composition contains a resin that is compatible with the resin component of the second resin composition. This allows the resin fixing portion and the resin flow path wall portion to be fused together.

[0066] "Having compatibility" means that the resin components constituting the resin fixing portion and the resin flow path wall portion mix without separating in an atmosphere in which the resin components constituting the resin fixing portion and the resin flow path wall portion melt. "The resin fixing portion and the resin flow path wall portion are fused together" means that the resin flow path wall portion and the resin fixing portion are fixed together at room temperature (e.g., 23°C) without the use of a fastener (e.g., adhesive, screw, etc.).

[0067] The first resin composition may contain at least one of a filler and a compounding agent, as needed. Examples of the filler and compounding agent include the same fillers and compounding agents as those exemplified as the fillers and compounding agents that can be contained in the resin composition.

[0068] (2.4) Internal Flow Channel The hollow article has an internal flow channel. The internal flow channel is located inside the hollow article. The shape of the internal flow channel is not particularly limited and may be appropriately selected depending on the application of the hollow article, etc.

[0069] The hollow article having an internal flow path means that the hollow article has a supply port and a recovery port. The supply port and the recovery port are connected via an internal flow path. Each of the supply port and the recovery port (hereinafter referred to as "supply port, etc.") may have a connecting part. Examples of connecting parts include male connectors (nipples). If each of the supply port, etc. does not have a connecting part, the hollow article may be processed to connect the supply section and the recovery section. Examples of processing methods include threading. The supply section supplies the heat exchange medium to the supply port. The recovery section recovers the heat exchange medium from the recovery port. If the hollow article is a rectangular parallelepiped having two main surfaces, each of the supply port and the recovery port may be located on one of the two main surfaces and one of the four side surfaces. For example, the supply port and the recovery port may be located on the same main surface, on different main surfaces, or only on the side surfaces of the hollow article. The supply port, etc. may be formed by a flow path wall portion or at least one of a pair of metal plates.

[0070] (2.5) Partition Member The hollow article may further have a partition member. The partition member separates the internal flow path. This allows the internal flow path to be designed more freely.

[0071] The partition member is disposed between a pair of metal plates within the internal flow path. The partition member is, for example, fixed to at least one of the pair of metal plates. When the partition member is fixed to one of the pair of metal plates, the partition member may or may not be in contact with the other of the pair of metal plates. When the partition member is in contact with the other of the pair of metal plates and is made of resin, the partition member may be bonded to the other of the pair of metal plates. The partition member may be made of either resin or metal. Examples of resins constituting the partition member include the same resins as those exemplified as resins constituting the resin flow path wall portion. Examples of metals constituting the partition member include the same metals as those exemplified as metals constituting the metal plates. The method for fixing the partition member to at least one of the pair of metal plates is appropriately selected depending on the material of the partition member, and examples include welding, a known adhesive, mechanical fastening, and welding. These fixing methods may be used alone or in combination. When the partition member is made of metal, the partition member and at least one of the pair of metal plates may be integrally molded. When the partition member is made of resin, the partition member and the flow path wall portion may be integrally molded.

[0072] When the partition member is made of metal, the partition member and at least one of the pair of metal plates may be an integrally molded metal part.

[0073] (2.6) Uses The hollow article can be used in a temperature control device, etc. The temperature control device controls the temperature of a heat exchange object.

[0074] When the hollow article is intended for use as a hollow article, a heat exchange medium may circulate through the internal flow path. The heat exchange medium exchanges heat with the heat exchange target. The heat exchange medium is a cooling medium or a heating medium, and is selected appropriately depending on the type of the heat exchange target, etc. The cooling medium refers to a medium for removing heat from the heat exchange target. Examples of the cooling medium include a cooling liquid and a cooling gas. The cooling liquid is not particularly limited as long as it is a liquid commonly used for cooling, and examples include water, oil, glycol-based aqueous solution, air conditioner refrigerant, non-conductive liquid, and phase-change liquid. Examples of the cooling gas include air and nitrogen gas. The temperature of the cooling medium is adjusted appropriately depending on the type of the heat exchange target, etc. The heating medium refers to a medium for providing heat to the heat exchange target. Examples of the heating medium include a heating liquid and a heating gas, etc. The heating liquid is not particularly limited as long as it is a liquid commonly used as a heating liquid, and examples thereof include water, oil, glycol-based aqueous solution, air conditioner refrigerant, non-conductive liquid, and phase-change liquid. Examples of the heating gas include air and water vapor. The temperature of the heating medium is adjusted appropriately depending on the type of heat exchange medium, etc.

[0075] (3) First Embodiment An example of a hollow article according to the present disclosure will be described with reference to FIGS. 1 to 5.

[0076] (3.1) Hollow Article As shown in Fig. 1, the hollow article 1A according to the first embodiment of the present disclosure includes a metal plate 11A, a metal plate 12A (see Fig. 2), a resin flow path wall portion 13A, a resin fixing portion 14A, and a partition member 15 (see Figs. 3 and 4). The metal plate 11A and the metal plate 12A are an example of a pair of metal plates. The hollow article 1A is a rectangular parallelepiped object.

[0077] In this embodiment, one side of the hollow article 1A in the longitudinal direction is defined as the positive X-axis direction (hereinafter also referred to as the "front side"), and the opposite side is defined as the negative X-axis direction (hereinafter also referred to as the "rear side"). One side of the hollow article 1A in the lateral direction is defined as the positive Y-axis direction (hereinafter also referred to as the "right side"), and the opposite side is defined as the negative Y-axis direction (hereinafter also referred to as the "left side"). One side of the hollow article 1A in the thickness direction is defined as the positive Z-axis direction (hereinafter also referred to as the "upper side"), and the opposite side is defined as the negative Z-axis direction (hereinafter also referred to as the "lower side"). The X-axis, Y-axis, and Z-axis are each perpendicular to one another. Note that these directions do not limit the orientation of the hollow article 1A of the present disclosure during use.

[0078] Hereinafter, the "metal plate 11A and the metal plate 12A" may also be referred to as "a pair of metal plates 11A, 12A."

[0079] The metal plate 12A, partition member 15, resin flow path wall portion 13A, and metal plate 11A are arranged in this order as shown in Figures 3 and 4. The resin flow path wall portion 13A is sandwiched between the pair of metal plates 11A and 12A. The resin fixing portion 14A contacts the peripheral portions of the pair of metal plates 11A and 12A, fixing the metal plate 12A to the metal plate 11A.

[0080] As shown in Fig. 1, the hollow article 1A has an upper main surface TS1 and a lower main surface BS1 (see Fig. 2). A pair of connection portions 131 of the resin flow path wall portion 13A are arranged on the upper main surface TS1 side of the hollow article 1A. The upper main surface TS1 and the lower main surface BS1 are an example of a pair of main surfaces.

[0081] The hollow article 1A has an internal flow path R1 therein. Specifically, the internal flow path R1 is formed by a metal plate 12A and a resin flow path wall portion 13A, as shown in Figures 3 and 4. A cooling medium flows through the internal flow path R1. The cooling medium is an example of a heat exchange medium.

[0082] (3.1.1) Metal Plates The pair of metal plates 11A, 12A are flat plates. The metal plate 11A constitutes an upper main surface TS1. The metal plate 12A constitutes a lower main surface BS1. The metal plate 11A has a pair of through holes H11A (supply port and recovery port) (see FIG. 1).

[0083] The metal plate 11A has two notches A11 (see FIG. 1 ). One of the two notches A11 is located on the rear left side of the periphery of the metal plate 11A. The other of the two notches A11 is located on the front right side of the periphery of the metal plate 11A.

[0084] The pair of metal plates 11A, 12A have two positioning holes B11 (see FIG. 1). One of the two positioning holes B11 is located on the rear left side of the metal plate 11A. The other of the two notches A11 is located on the rear right side of the metal plate 11A.

[0085] Each of the pair of metal plates 11A, 12A has an uneven structure at a portion that comes into contact with the resin fixing portion 14A.

[0086] (3.1.2) Resin Flow Path Wall Portion The resin flow path wall portion 13A is a plate-like member.

[0087] The resin flow path wall 13A has a pair of connection portions 131 (corresponding to a supply port and a recovery port) (see FIG. 1). The pair of connection portions 131 are exposed from the through-holes H11A of the metal plate 11A. As shown in FIG. 4, the connection portions 131 have an opening H131 and a hollow portion R131. The hollow portion R131 connects the opening H131 to the internal flow path R1.

[0088] As shown in Figures 3 and 4, the resin flow path wall 13A further has a recessed portion R132. The recessed portion R132 is located in the center of the lower surface of the resin flow path wall 13A in the front-to-rear direction (X-axis direction) and the left-to-right direction (Y-axis direction). The metal plate 12A has an upper main surface TS12 (see Figure 3). At least a portion of the lower surface of the resin flow path wall 13A surrounding the recessed portion R132 is in physical contact with the upper main surface TS12 of the metal plate 12A. As a result, an internal flow path R1 is formed between the recessed portion R132 and the upper main surface TS12 of the metal plate 12A.

[0089] (3.1.3) Resin Fixing Portion The resin fixing portion 14A fixes the metal plate 12A to the metal plate 11A.

[0090] As shown in Figures 3 and 4, a gap R10 is formed between the pair of metal plates 11A and 12A. The gap R10 represents a space between the pair of metal plates 11A and 12A where the resin flow path wall 13A and the peripheral edges of the pair of metal plates 11A and 12A are not in contact. The gap R10 is formed around the entire periphery of the pair of metal plates 11A and 12A. The resin fixing portion 14A is filled in the gap R10. In other words, the resin fixing portion 14A is in physical contact with the peripheral edge of the lower main surface BS11 of the metal plate 11A, the peripheral edge of the upper main surface TS12 of the metal plate 12A, and the side surface of the resin flow path wall 13A.

[0091] The resin fixing portion 14A has two gate marks A14 (see FIG. 1 ) only on the upper main surface TS1 of the hollow article 1A. In the first embodiment, the two gate marks A14 are located outside the periphery of the metal plate 11A. One of the two gate marks A14 is located on the rear left side of the upper main surface TS1 of the hollow article 1A. The other of the two cutout portions A11 is located on the front right side of the upper main surface TS1 of the hollow article 1A.

[0092] (3.1.4) Partition Member The partition member 15 divides the internal flow path R1. The partition member 15 has a plurality of partition wall portions 151. The plurality of partition wall portions 151 are arranged at predetermined intervals along the Y-axis direction. Each of the plurality of partition wall portions 151 is a long plate-like object, which increases the heat transfer area, improves the amount of heat transfer, and controls the flow direction of the cooling medium. The partition member 15 may be fixed to the metal plate 12A. Methods for fixing the partition member 15 to the metal plate 12A include the same methods as those exemplified above as the fixing methods.

[0093] (3.1.5) Flow of Cooling Medium The hollow article 1A is installed, for example, so that the heat-generating body (i.e., an example of a heat-exchange body) is in contact with the lower main surface BS1 of the hollow article 1A. In this case, an external supply unit is connected to one of the two connection parts 131. An external recovery unit is connected to the other of the two connection parts 131. The supply unit supplies the cooling medium to the connection part 131. The recovery unit recovers the cooling medium from the connection part 131. Heat from the heating body is conducted to the cooling medium filled in the internal flow path R1 via at least one of the pair of metal plates 11A, 12A.

[0094] The cooling medium is supplied to the opening H131 of the connection portion 131. The cooling medium supplied to the opening H131 moves to the internal flow path R1 through the hollow portion R131 of the connection portion 131. Most of the cooling medium moves through the internal flow path R1 toward the other connection portion 131. At this time, the cooling medium exchanges heat with at least one of the pair of metal plates 11A, 12A. Next, the cooling medium moves to the opening H131 through the hollow portion R131 of the other connection portion 131 and is collected in an external collection section. In this way, the cooling medium absorbs heat from the heat-generating element inside the hollow article 1A and is collected outside the hollow article 1A. As a result, the hollow article 1A promotes heat dissipation from the heat-generating element. In other words, the hollow article 1A controls the temperature of the heat-generating element.

[0095] (3.2) Method for Manufacturing Hollow Article The method for manufacturing a hollow article according to the first embodiment of the present disclosure includes a preparation step, a roughening step, an assembly step, and an insert molding step, which are performed in this order.

[0096] (3.2.1) Mold In the first embodiment, a mold 30A is used. The mold 30A has a two-plate structure. As shown in FIG. 5 , the mold 30A has a movable mold 31A and a fixed mold 32. The movable mold 31A has a first surface S31 that contacts the metal plate 11A and two gates G. The fixed mold 32 has a second surface S32 that contacts the metal plate 11B and two pins (not shown) that fit into the positioning holes B11. The gates G are formed only on the first surface S31. The position of the gates G is outside the periphery of the metal plate 11A. The position of the gates G and the position of the gate marks A14 are the same. The pins of the fixed mold 32 are an example of a fitting portion.

[0097] (3.2.2) Preparation Step In the preparation step, the metal plate 11A, the metal plate 12A, the resin flow path wall portion 13A, and the partition member 15 are prepared. The preparation methods for the metal plate 11A, the metal plate 12A, and the resin flow path wall portion 13A are the same as the methods exemplified in (1.2) above. The preparation method for the partition member 15 may be any known method.

[0098] (3.2.3) Roughening Step In the roughening step, a concave-convex structure is formed on each of the metal plates 11A and 12A at a position where the metal plates 11A and 12A come into contact with the resin fixing portion 14A. The method for forming the concave-convex structure is the same as the method exemplified in (1.4) above.

[0099] (3.2.4) Assembly Process In the assembly process, the resin flow path wall portion 13A is sandwiched between a pair of metal plates 11A, 12A inside the mold 30A, and a gap R10 is formed where the pair of metal plates 11A, 12A face each other. At this time, the positioning holes B11 of the pair of metal plates 11A, 12A are fitted onto the pins of the fixed mold 32. This results in the insert body 20A.

[0100] (3.2.5) Insert Molding Process In the insert molding process, the resin fixing portion 14A is formed in the gap R10 by insert molding. Specifically, an injection molding machine is used to supply a melt of the first resin composition to the mold 30A, and the melt of the first resin composition is filled into the molding space at high pressure from two gates G. The molding space refers to the space in which the resin fixing portion 14A is formed. The molding space includes the gap R10. Next, the melt of the first resin composition in the mold 30A is cooled and solidified. This results in a hollow article 1A.

[0101] (3.3) Effects and Benefits As described with reference to FIGS. 1 to 5 , the hollow article manufacturing method of the first embodiment manufactures a hollow article 1A having an upper main surface TS1 and a lower main surface BS1. The hollow article manufacturing method of the first embodiment includes a preparation process, an assembly process, and an insert molding process. The mold 30A has a first surface S31 that contacts the metal plate 11A, a second surface S32 that contacts the metal plate 12A, and two gates G. The gates G are formed only on the first surface S31. As a result, the gates G and the resin flow path wall 13A do not face each other, as shown in FIG. 5 . Therefore, in the insert molding process, the resin flow path wall 13A is less likely to be directly subjected to injection pressure. This makes the resin flow path wall 13A less likely to break than when the gates G and the resin flow path wall 13A face each other. As a result, the hollow article manufacturing method of the first embodiment can suppress a decrease in yield.

[0102] As described with reference to Figures 1 to 5, the pair of metal plates 11A, 12A have two positioning holes B11. The mold 30A has two pins that fit into the two positioning holes B11. This allows the pair of metal plates 11A, 12A to be positioned at specific positions within the mold 30A. As a result, the method for manufacturing a hollow article according to the first embodiment can further suppress a decrease in yield.

[0103] As described with reference to Figures 1 to 5, in the insert molding process, the gate G is positioned outside the periphery of the metal plate 11A. This allows the resin fixing portion 14A to be formed, surrounding the periphery of the pair of metal plates 11A, 12A. Furthermore, in the insert molding process, the resin flow path wall portion 13A is less likely to be directly subjected to injection pressure. As a result, the method for manufacturing a hollow article according to the first embodiment can suppress a decrease in yield.

[0104] 1 to 5, in the insert molding process, the metal plate 11A has a notch A11 at a position on its periphery corresponding to the position of the gate G. This allows the length (width) of the resin fixing portion 14A in the Y-axis direction to be shorter than when the metal plate 11A does not have the notch A11. As a result, the hollow article manufacturing method of the first embodiment can manufacture a more compact hollow article 1A.

[0105] As described with reference to Figures 1 to 5, the method for manufacturing a hollow article according to the first embodiment further includes a roughening step. This allows a portion of the resin fixing portion 14A to penetrate into the recesses of the uneven structure of the pair of metal plates 11A and 12A. This allows the resin fixing portion 14A to be more firmly fixed to each of the pair of metal plates 11A and 12A. As a result, a hollow article 1A that maintains excellent airtightness for a long period of time can be obtained.

[0106] As described with reference to FIGS. 1 to 5, the hollow article 1A has an upper main surface TS1 and a lower main surface BS1. The hollow article 1A includes a pair of metal plates 11A, 12A, a resin flow path wall 13A, and a resin fixing portion 14A. An internal flow path R1 for circulating a heat exchange medium is formed by the metal plate 12A and the resin flow path wall 13A. The resin fixing portion 14A has two gate marks A14 only on the upper main surface TS1. As a result, in the insert molding process of the hollow article 1A, the resin flow path wall 13A is not directly subjected to the injection pressure. Therefore, the resin flow path wall 13A is less deformed than when the gate marks A14 and the resin flow path wall 13A are opposite each other. As a result, the hollow article 1A maintains excellent airtightness over a long period of time.

[0107] 1 to 5, the gate mark A14 is located outside the periphery of the pair of metal plates 11A, 12A. This makes it less likely that the resin flow path wall 13A will be directly subjected to injection pressure during insert molding of the resin fixing portion 14A. This ensures that the internal flow path R1 is more reliably sealed.

[0108] 1 to 5, the metal plate 11A has a notch A11 at a position corresponding to the position of the gate mark A14 on its periphery. This makes the length (width) of the resin fixing portion 14A in the Y-axis direction shorter than when the metal plate 11A does not have the notch A11. As a result, the hollow article 1A is more compact.

[0109] As described with reference to Figures 1 to 5, each of the pair of metal plates 11A, 12A has a concave-convex structure at the portion that contacts the resin fixing portion 14A. This allows a portion of the resin fixing portion 14A to fit into the recesses of the concave-convex structure of the pair of metal plates 11A, 12A. As a result, the pair of metal plates 11A, 12A are more firmly bonded to the resin fixing portion 14A. This allows the airtightness of the hollow article 1A to be maintained for a longer period of time.

[0110] (4) Second Embodiment An example of a hollow article according to the present disclosure will be described with reference to FIGS.

[0111] (4.1) Hollow Article A hollow article 1B according to a second embodiment of the present disclosure is essentially the same as the hollow article 1A according to the first embodiment, except that the flow path wall is made of metal. As shown in FIG. 6, the hollow article 1B includes a metal plate 11B, a metal plate 12B, a metal flow path wall 13B (see FIG. 7), and a resin fixing portion 14B. The metal plate 12B and the metal flow path wall 13B form an integrally molded metal product 120 (see FIG. 7). The metal plate 11B and the metal plate 12B are an example of a pair of metal plates.

[0112] In the second embodiment, the metal plate 11B has one through hole C11 (see FIG. 6 ). The gate mark A14 is located within the through hole C11. As shown in FIG. 7 , the resin fixing portion 14B has a filling portion 14B1 that is filled in an internal space R14 that communicates with the through hole C11 but does not communicate with the internal flow path R1. The internal space R14 is formed by the pair of metal plates 11B, 12B and the metal flow path wall portion 13B.

[0113] (4.2) Method for Manufacturing Hollow Article The method for manufacturing a hollow article according to the second embodiment of the present disclosure includes a preparation step, a roughening step, an assembly step, and an insert molding step, which are performed in this order.

[0114] (4.2.1) Mold The mold 30B of the second embodiment is similar to the mold 30A of the first embodiment, except that the number of gates G of the movable mold 31B is one.

[0115] (4.2.2) Preparation Step In the preparation step, the metal plate 11B and the integrally molded metal product 120 (i.e., the metal plate 12B and the metal flow path wall portion 13B) are prepared. The preparation methods for the metal plate 11B and the integrally molded metal product 120 are the same as the methods exemplified in (1.2) above.

[0116] (4.2.3) Roughening Step In the roughening step, a concave-convex structure is formed on the portion of each of the pair of metal plates 11B, 12B that comes into contact with the resin fixing portion 14B. The method for forming the concave-convex structure is the same as the method exemplified in (1.4) above.

[0117] (4.2.4) Assembly Process In the assembly process, the metal flow path wall portion 13B is sandwiched between the pair of metal plates 11B, 12B inside the mold 30B to form a gap R10 where the pair of metal plates 11B, 12B face each other and an internal space R14. At this time, the positioning holes B11 of the pair of metal plates 11B, 12B are fitted onto the pins of the fixed mold 32. This results in the insert body 20B.

[0118] (4.2.5) Insert Molding Process In the insert molding process, the resin fixing portion 14B is formed in the gap R10 and the internal space R14 by insert molding. Specifically, an injection molding machine is used to supply a melt of the first resin composition to the mold 30B, and the melt of the first resin composition is filled at high pressure into the molding space from one gate G. The molding space refers to the space in which the resin fixing portion 14B is formed. The molding space includes the gap R10 and the internal space R14. Next, the melt of the first resin composition in the mold 30B is cooled and solidified. This results in a hollow article 1B.

[0119] (4.3) Effects and Benefits As described with reference to FIGS. 6 to 8 , the hollow article manufacturing method of the second embodiment produces a hollow article 1B having an upper main surface TS1 and a lower main surface BS1. The hollow article manufacturing method of the second embodiment includes a preparation process, an assembly process, and an insert molding process. The mold 30B has a first surface S31 that contacts the metal plate 11B, a second surface S32 that contacts the metal plate 12B, and one gate G. The gate G is formed only on the first surface S31. As a result, the gate G and the metal flow path wall 13B do not face each other, as shown in FIG. 8 . Therefore, in the insert molding process, the metal flow path wall 13B is less likely to be directly subjected to injection pressure. This makes the metal flow path wall 13B less likely to break than when the gate G and the metal flow path wall 13B face each other. As a result, the hollow article manufacturing method of the second embodiment can suppress a decrease in yield.

[0120] 6 to 8, the pair of metal plates 11B, 12B have two positioning holes B11. The mold 30B has two pins that fit into the two positioning holes B11. This makes it possible to further suppress a decrease in yield in the method for manufacturing a hollow article according to the second embodiment.

[0121] As described with reference to Figures 6 to 8, the metal plate 11A has one through hole C11. The internal space R14 is formed by the pair of metal plates 11B, 12B and the metal flow path wall portion 13B. In the insert molding process, the position of the gate G includes a position facing the through hole C11. As a result, the internal space R14 is filled with a molten first resin composition, forming the resin fixing portion 14B. In other words, the contact area between the pair of metal plates 11B, 12B and the resin fixing portion 14B is larger than when the internal space R14 is not formed. As a result, each of the pair of metal plates 11B, 12B is more strongly fixed. Therefore, a hollow article 1B with excellent airtightness over a long period of time is obtained.

[0122] 6 to 8, the method for producing a hollow article according to the second embodiment further includes a roughening step, which allows a hollow article 1B to be obtained that has excellent airtightness for a long period of time.

[0123] As described with reference to Figures 6 to 8, the hollow article 1B has an upper main surface TS1 and a lower main surface BS1. The hollow article 1B includes a pair of metal plates 11B, 12B, a metal flow path wall 13B, and a resin fixing portion 14B. An internal flow path R1 for circulating a heat exchange medium is formed by the pair of metal plates 11B, 12B and the metal flow path wall 13B. The resin fixing portion 14B has one gate mark A14 only on the upper main surface TS1. As a result, in the insert molding process of the hollow article 1B, the metal flow path wall 13B is not directly subjected to the injection pressure. Therefore, the metal flow path wall 13B is less deformed than when the gate mark A14 and the metal flow path wall 13B are opposite each other. As a result, the hollow article 1B maintains excellent airtightness over a long period of time.

[0124] As described with reference to Figures 6 to 8, the metal plate 11B has one through hole C11. The position of the gate mark A14 includes a position within the through hole C11. The resin fixing portion 14B has a filling portion 14B1 that is filled in an internal space R14 that is connected to the through hole C11 but not connected to the internal flow path R1. The internal space R14 is formed by the pair of metal plates 11B, 12B and the metal flow path wall portion 13B. This results in a larger contact area between the pair of metal plates 11B, 12B and the resin fixing portion 14B than when the resin fixing portion 14B does not have the filling portion 14B1. As a result, each of the pair of metal plates 11B, 12B is more strongly fixed. Therefore, the hollow article 1B has excellent airtightness over a long period of time.

[0125] 6 to 8, each of the pair of metal plates 11B, 12B has an uneven structure at the portion that comes into contact with the resin fixing portion 14B, which allows the airtightness of the hollow article 1B to be maintained for a longer period of time.

[0126] (5) Third Embodiment An example of a hollow article according to the present disclosure will be described with reference to FIGS.

[0127] (5.1) Hollow Article A hollow article 1C according to a third embodiment of the present disclosure is the same as the hollow article 1A according to the first embodiment, except for the position of the gate marks. As shown in Fig. 9, the hollow article 1C includes a metal plate 11C, a metal plate 12C, a resin flow path wall portion 13A (see Fig. 11), and a resin fixing portion 14C. The metal plates 11C and 12C are an example of a pair of metal plates.

[0128] The metal plate 11C has the same configuration as the metal plate 11A of the first embodiment except that it does not have the two cutout portions A11 (see FIG. 1). The metal plate 12C has the same configuration as the metal plate 12A of the first embodiment except that it has two through holes D12 (see FIGS. 10 and 11). The resin fixing portion 14C has the same configuration as the resin fixing portion 14A except that it does not cover the side surfaces of the metal plate 11C and the metal plate 12C.

[0129] (5.2) Manufacturing method of hollow article The manufacturing method of a hollow article according to the third embodiment of the present disclosure is similar to the manufacturing method of a hollow article according to the first embodiment, except for the mold used. The mold of the third embodiment is similar to the mold 30A of the first embodiment, except for the gate G of the mold facing the through hole D12 of the metal plate 12C. The manufacturing method of a hollow article according to the third embodiment of the present disclosure includes a preparation step, a roughening step, an assembly step, and an insert molding step. The preparation step, roughening step, assembly step, and insert molding step are performed in this order.

[0130] (5.3) Effects and Benefits As described with reference to Figures 9 to 11, the hollow article manufacturing method of the third embodiment produces a hollow article 1C having an upper main surface TS1 and a lower main surface BS1. The hollow article manufacturing method of the third embodiment includes a preparation process, an assembly process, and an insert molding process. The mold of the third embodiment has a first surface S31 that contacts the metal plate 11C, a second surface S32 that contacts the metal plate 12C, and two gates G. The gates G are formed only on the second surface S32. As a result, the gates G and the resin flow path wall 13A do not face each other. Therefore, in the insert molding process, the resin flow path wall 13A is less likely to be directly subjected to injection pressure. As a result, the resin flow path wall 13A is less likely to break than when the gates G and the resin flow path wall 13A face each other. As a result, the hollow article manufacturing method of the third embodiment can suppress a decrease in yield.

[0131] 9 to 11, the method for producing a hollow article according to the third embodiment further includes a roughening step, which makes it possible to obtain a hollow article 1C that has excellent airtightness for a long period of time.

[0132] As described with reference to Figures 9 to 11, the hollow article 1C has an upper main surface TS1 and a lower main surface BS1. The hollow article 1C includes a pair of metal plates 11C, 12C, a resin flow path wall 13A, and a resin fixing portion 14C. An internal flow path R1 for circulating a heat exchange medium is formed by the metal plate 11C and the resin flow path wall 13A. The resin fixing portion 14C has two gate marks A14 only on the lower main surface BS1. As a result, in the insert molding process of the hollow article 1C, the resin flow path wall 13A is not directly subjected to the injection pressure. Therefore, the resin flow path wall 13A is less deformed than when the gate marks A14 and the resin flow path wall 13A are opposite each other. As a result, the hollow article 1C maintains excellent airtightness over a long period of time.

[0133] 9 to 11, each of the pair of metal plates 11C, 12C has an uneven structure at the portion that comes into contact with the resin fixing portion 14C, which allows the airtightness of the hollow article 1C to be maintained for a longer period of time.

[0134] The embodiments of the present invention have been described above with reference to the drawings. However, the present invention is not limited to the above embodiments and can be embodied in various forms without departing from the spirit and scope of the present invention. The drawings mainly show each component in a schematic manner for ease of understanding, and the thickness, length, number, etc. of each component shown in the drawings may differ from the actual components due to the convenience of creating the drawings. The materials, shapes, dimensions, etc. of each component shown in the above embodiments are merely examples and are not particularly limited, and various modifications are possible within a scope that does not substantially depart from the effects of the present invention.

[0135] The disclosure of Japanese Patent Application No. 2023-155839, filed on September 21, 2023, is incorporated herein by reference in its entirety. All documents, patent applications, and technical standards described 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 method for manufacturing a hollow article having a pair of main surfaces, the hollow article comprising: a pair of metal plates constituting the pair of main surfaces; a flow path wall portion sandwiched between the pair of metal plates; and a resin fixing portion fixing one of the pair of metal plates to the other of the pair of metal plates; an internal flow path for circulating a heat exchange medium is formed by at least one of the pair of metal plates and the flow path wall portion; the method for manufacturing the hollow article comprises: preparing the pair of metal plates and the flow path wall portion; sandwiching the flow path wall portion between the pair of metal plates to form a gap between the pair of metal plates; and forming the resin fixing portion in the gap by insert molding; 2. A method for manufacturing a hollow article according to claim 1, wherein the pair of metal plates have a plurality of positioning holes, and the mold has a plurality of fitting portions that fit into the positioning holes.

3. A method for manufacturing a hollow article as described in claim 1 or claim 2, wherein in forming the resin fixing portion, the position of the gate includes a position outside the periphery of the pair of metal plates.

4. The method for manufacturing a hollow article according to claim 3, wherein at least one of the pair of metal plates has a notch on its periphery at a position corresponding to the position of the gate.

5. A method for manufacturing a hollow article as described in claim 1 or claim 2, wherein at least one of the pair of metal plates has at least one through hole, a space communicating with the through hole but not communicating with the flow path wall portion is formed by at least one of the pair of metal plates and the flow path wall portion, and in forming the resin fixing portion, the position of the gate includes a position facing the through hole.

6. A method for manufacturing a hollow article as described in claim 1 or claim 2, further comprising forming a concave-convex structure in the portion of each of the pair of metal plates that contacts the resin fixing portion, and forming the concave-convex structure is performed before forming the gap.

7. A hollow article having a pair of main surfaces, the hollow article comprising: a pair of metal plates constituting the pair of main surfaces; a flow path wall portion sandwiched between the pair of metal plates; and a resin fixing portion fixing one of the pair of metal plates to the other of the pair of metal plates, an internal flow path for circulating a heat exchange medium is formed by at least one of the pair of metal plates and the flow path wall portion, and the resin fixing portion has at least one gate mark only on at least one of the pair of main surfaces.

8. The hollow article according to claim 7, wherein the location of the gate mark includes a location outside the periphery of the pair of metal plates.

9. The hollow article according to claim 8, wherein at least one of said pair of metal plates has a notch on its periphery at a position corresponding to the position of said gate mark.

10. A hollow article according to any one of claims 7 to 9, wherein at least one of the pair of metal plates has at least one through hole, the position of the gate mark includes a position within the through hole, the resin fixing portion has a filling portion that fills a space that communicates with the through hole but does not communicate with the internal flow path, and the space is formed by at least one of the pair of metal plates and the flow path wall portion.

11. The hollow article according to any one of claims 7 to 9, wherein each of the pair of metal plates has an uneven structure at a portion that comes into contact with the resin fixing portion.

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