Heat dissipation structure and battery equipped with the same

Abstract

The present invention provides a heat dissipation structure and a battery. The heat dissipation structure can adapt to various forms of heat sources, has excellent elastic deformability, has excellent heat dissipation efficiency, can improve the uniformity of heat dissipation of multiple heat sources, and can improve production efficiency. The present invention relates to a heat dissipation structure (1) and a battery. The heat dissipation structure (1) includes a plurality of heat dissipation members (20) and a support plate (10) for supporting the plurality of heat dissipation members (20). The heat dissipation member (20) includes: a plurality of buffer members (22) having a hollow or solid shape; and a heat conduction sheet (21) covering the outer side surface of the buffer member (22). The support plate (10) has a plurality of groove portions (15) for supporting the heat dissipation members (20) along a direction perpendicular to the length direction of the heat dissipation members (20). The groove portion (15) is a curved groove portion that is open on the heat dissipation member (20) side and recessed in the thickness direction, and is formed such that its radius of curvature (R2) is greater than the radius of curvature (R1) of the heat dissipation member (20), and its depth (T) is less than the circular conversion diameter (D) of the heat dissipation member (20).

Description

[0001] Cross-reference

[0002] This application claims priority based on Japanese Patent Application No. 2020-092967 filed on May 28, 2020, and the content described in this application is incorporated herein by reference. In addition, the content described in patents, patent applications, and documents cited in this application is incorporated herein by reference. Technical Field

[0003] The present invention relates to a heat dissipation structure and a battery including the heat dissipation structure. Background Art

[0004] The control systems of automobiles, airplanes, ships, or household or business-use electronic devices are becoming more precise and complex. Along with this, the integration density of small electronic components on circuit boards is continuously increasing. As a result, there is a strong desire to solve the problems of failures and shortened lifetimes of electronic components caused by heat generation around the circuit board.

[0005] In order to achieve rapid heat dissipation from the circuit board, conventionally, the circuit board itself has been made of a material with excellent heat dissipation properties, or a single means such as installing a heat sink or driving a cooling fan, or a combination of multiple means has been used. Among them, the method of forming the circuit board itself from a material with excellent heat dissipation properties, such as diamond, aluminum nitride (AlN), cubic boron nitride (cBN), etc., makes the cost of the circuit board extremely high. In addition, the arrangement of the cooling fan causes problems such as failures of rotating devices such as the fan, the necessity of maintenance for preventing failures, and difficulty in ensuring installation space. On the other hand, a heat sink is a simple member that can increase the surface area by forming a plurality of columnar or flat protrusions using a metal with high thermal conductivity (such as aluminum), and thus is widely used as a heat dissipation member (see Patent Document 1).

[0006] However, currently, worldwide, in order to reduce the load on the global environment, the trend of gradually converting conventional gasoline or diesel vehicles to electric vehicles is becoming active. In particular, in addition to European countries represented by France, the Netherlands, and Germany, electric vehicles are also becoming popular in China. In the popularization of electric vehicles, in addition to the development of high-performance batteries, it is also necessary to install a large number of charging stations, etc. In particular, the technological development for improving the charge and discharge functions of lithium-based automotive batteries is important. As is well known, the above-mentioned automotive batteries cannot fully exhibit their charge and discharge functions at temperatures above 60 degrees Celsius. Therefore, similar to the circuit board described above, improving heat dissipation is also emphasized in batteries.

[0007] In order to achieve rapid heat dissipation of the battery, the following structure is adopted: a water-cooling pipe is arranged on a frame made of a metal with excellent heat conductivity such as aluminum, a plurality of battery cells are arranged on the frame, and a rubber sheet with good adhesion is sandwiched between the battery cells and the bottom surface of the frame. In the battery with such a structure, the battery cells transfer heat to the frame through the rubber sheet, and heat is effectively removed through water cooling.

[0008] Prior art documents

[0009] Patent documents

[0010] Patent document 1: Japanese Patent Laid-Open No. 2008-243999 Summary of the invention

[0011] Problems to be solved by the invention

[0012] However, in the conventional battery as described above, the rubber sheet has lower heat conductivity than aluminum and graphite, so it is difficult to efficiently transfer heat from the battery cells to the frame. In addition, a method of sandwiching a spacer such as graphite instead of the rubber sheet can be considered, but since the lower surfaces of the plurality of battery cells are uneven and have a difference in height between the high and low planes, a gap is generated between the battery cells and the spacer, and the heat transfer efficiency is reduced. From this one example, it can also be seen that the battery cells can take various forms (including unevenness such as height differences or uneven or non-smooth surface states), so the requirement for adapting to various forms of the battery cells and achieving high heat transfer efficiency is increased. In addition, in order to achieve high heat transfer efficiency, it is preferable to uniformly dissipate heat from each of the plurality of battery cells so that the temperatures of the plurality of battery cells are uniform. Furthermore, it is desired that the heat dissipation structure returns to a shape close to the original shape when the battery cells are removed. In addition, an improvement in the productivity of the heat dissipation structure is also required. This applies not only to battery cells but also to other heat sources such as circuit boards, electronic components, or the main body of an electronic device. Meeting such requirements also helps the applicant achieve the sustainable development goal of "ensuring that everyone has access to cheap, reliable, and sustainable modern energy".

[0013] The present invention has been completed in view of the above problems, and an object thereof is to provide a heat dissipation structure and a battery including the heat dissipation structure, the heat dissipation structure being capable of adapting to various forms of a heat source, having excellent elastic deformability, excellent heat dissipation efficiency, being capable of improving the uniformity of heat dissipation of each of a plurality of heat sources, and being capable of improving productivity.

[0014] Means for solving the problems

[0015] (1) A heat dissipation structure according to an embodiment for achieving the above object includes a plurality of heat dissipation members for enhancing heat dissipation from a heat source and a support plate for supporting the plurality of heat dissipation members. The heat dissipation members include: a plurality of buffer members having a hollow or solid shape; and a heat conduction sheet for transferring heat from the heat source, covering the outer side surface of the buffer members. The support plate has a plurality of groove portions for supporting the heat dissipation members along a direction perpendicular to the length direction of the heat dissipation members. The groove portions are curved groove portions that are open on the heat dissipation member side and recessed in the thickness direction, and are formed such that their radius of curvature is greater than the radius of curvature of the heat dissipation members and their depth is less than the circle conversion diameter of the heat dissipation members.

[0016] (2) In a heat dissipation structure according to another embodiment, preferably, the support plate has at least one or more flow paths for allowing a cooling medium to flow along the length direction.

[0017] (3) In a heat dissipation structure according to another embodiment, preferably, the flow path is a through-path penetrating the support plate.

[0018] (4) In a heat dissipation structure according to another embodiment, preferably, the support plate can be a plate-like member made of metal.

[0019] (5) In a heat dissipation structure according to another embodiment, preferably, the heat dissipation member can be a cylindrical member having a hollow portion along the length direction.

[0020] (6) In a heat dissipation structure according to another embodiment, preferably, the buffer member is a cylindrical buffer member having the hollow portion in the length direction, and the heat conduction sheet is wound around the outer side surface of the cylindrical buffer member in a spiral shape toward the length direction.

[0021] (7) In a heat dissipation structure according to another embodiment, preferably, the heat conduction sheet and the buffer member can have a form that integrally advances in a spiral shape in one direction.

[0022] (8) A heat dissipation structure according to another embodiment can preferably have a heat conductive oil on the surface of the heat conduction sheet for enhancing the heat conductivity from a heat source in contact with the surface of the heat conduction sheet to the surface.

[0023] (9) In a heat dissipation structure according to another embodiment, preferably, the heat conductive oil can contain silicone oil and a heat conductive filler, and the heat conductivity of the heat conductive filler is higher than that of the silicone oil and includes one or more of metal, ceramic, or carbon.

[0024] (10) A battery according to an embodiment has one or more battery cells as heat sources in a housing, and a heat dissipation structure according to any one of the above is provided between the battery cell and the housing.

[0025] Advantages of the Invention

[0026] According to the present invention, a heat dissipation structure and a battery including the heat dissipation structure can be provided. The heat dissipation structure can adapt to various forms of heat sources, has excellent elastic deformability and heat dissipation efficiency, can improve the uniformity of heat dissipation of multiple heat sources, and can achieve an improvement in productivity. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 A plan view showing the heat dissipation structure according to the first embodiment.

[0028] Figure 2 Respectively show Figure 1 A sectional view taken along line A-A in [reference numeral omitted] and an enlarged view of a part C thereof.

[0029] Figure 3 Show Figure 1 A sectional view taken along line B-B in [reference numeral omitted].

[0030] Figure 4 With the same viewing angle as Figure 2 A view showing the heat dissipation structure according to the second embodiment.

[0031] Figure 5 A view showing a manufacturing process of a heat dissipation member constituting the heat dissipation structure for explanation.

[0032] Figure 6 A view showing a manufacturing process of a support plate constituting the heat dissipation structure according to the first embodiment for explanation.

[0033] Figure 7 A view showing a preferred manufacturing process of a modified example of a heat dissipation member constituting the heat dissipation structure for explanation.

[0034] Figure 8 A longitudinal sectional view of a battery including the heat dissipation structure.

[0035] Figure 9 Respectively show a sectional view when the battery cells are horizontally placed in contact with the side surfaces of the heat dissipation structure, a partial enlarged view thereof, and a partial sectional view when the battery cells expand during charge and discharge.

[0036] [Reference Signs]

[0037] 1, 1a ··· Heat dissipation structure,

[0038] 10, 10a ··· Support plate,

[0039] 15 ··· Groove portion

[0040] 17, 17a ··· Through - path

[0041] 20, 20a ··· Heat - dissipating member

[0042] 21 ··· Heat - conducting sheet

[0043] 22 ··· Buffer member

[0044] 23, 23a ··· Hollow portion

[0045] 40 ··· Battery

[0046] 41 ··· Housing

[0047] 43 ··· Flow path

[0048] 45 ··· Cooling medium

[0049] 50 ··· Battery cell (an example of heat source)

[0050] R1 ··· Curvature radius of heat - dissipating member

[0051] R2 ··· Curvature radius of groove portion

[0052] T ··· Depth of groove portion

[0053] D ··· Equivalent diameter in terms of circle of heat - dissipating member Detailed implementation mode

[0054] Next, with reference to the accompanying drawings, the implementation modes of the present invention will be described. In addition, the implementation modes described below do not limit the invention defined in the claims, and moreover, not all of the elements and their combinations described in the implementation modes are necessary for the solution means of the invention.

[0055] 1. Heat - dissipating structure

[0056] (First implementation mode)

[0057] Figure 1 The top view showing the heat - dissipating structure of the first implementation mode Figure 2 Respectively show Figure 1 The cross - sectional view taken along line A - A in Figure 3 and the enlarged view of a part C thereof Figure 1 The cross - sectional view taken along line B - B in Figure 2 and Figure 3 In this implementation mode, the heat source is disposed above the plane of Figure 1In [the figure], the heat dissipation structure 1 includes 10 heat dissipation members 20, but the number of the heat dissipation members 20 is not particularly limited. The same applies to the subsequent embodiments.

[0058] (1) Schematic Structure

[0059] The heat dissipation structure 1 according to the first embodiment is a member including a plurality of heat dissipation members 20 that improve heat dissipation from a heat source and a support plate 10 that supports the plurality of heat dissipation members 20. The heat dissipation member 20 includes: a plurality of buffer members 22 having a hollow or solid shape; and a heat conduction sheet 21 that is a sheet for transferring heat from the heat source and covers the outer side surface of the buffer member 22. The support plate 10 includes a plurality of groove portions 15 that support the heat dissipation members 20 along a direction ([ Figure 1 the left - right direction) perpendicular to the length direction of the heat dissipation member 20. The groove portion 15 is a curved groove portion that is open on the heat dissipation member 20 side and recessed in the thickness direction. The groove portion 15 is formed such that its curvature radius R2 is larger than the curvature radius R1 of the heat dissipation member 20, and its depth T is smaller than the circular - equivalent diameter D of the heat dissipation member 20 (refer to Figure 2 ). The heat dissipation member 20 may also be referred to as a "heat conduction member" or a "heat - conducting member". It should be noted that the "curvature radius" is the radius of the positive circle that is closest to the degree of curvature of the curve in the cross - section when cutting perpendicularly to the length direction of the heat dissipation member 20 and the groove portion 15. In addition, the "circular - equivalent diameter" is the diameter of the positive circle having the same area as the area of the tube cross - section when cutting the heat dissipation member 20 perpendicularly to its length direction. The same applies to the subsequent embodiments.

[0060] (2) Heat Conduction Sheet

[0061] The heat conduction sheet 21 is preferably a sheet that travels while being wound in a spiral shape. The constituent material of the heat conduction sheet 21 is not limited, and it is preferably a sheet containing carbon, and more preferably a sheet composed of 90 mass% or more of carbon. For example, the heat conduction sheet 21 may also be a graphite - made film obtained by firing a resin. However, the heat conduction sheet 21 may also be a sheet containing carbon and resin. In this case, the resin may also be a synthetic fiber, and in this case, aramid fiber can be appropriately used as the resin. The "carbon" referred to in this application is broadly interpreted to include any structure of carbon (element symbol: C) such as graphite, carbon black with lower crystallinity than graphite, diamond, and diamond - like carbon having a structure close to diamond. In this embodiment, the heat conduction sheet 21 may be a thin sheet obtained by curing a material in which graphite fibers and carbon particles are mixed and dispersed in a resin. The heat conduction sheet 21 may be carbon fiber woven into a net shape, and further, it may be blended or interwoven. It should be noted that various fillers such as graphite fibers, carbon particles, or carbon fibers are also all included in the concept of carbon fillers.

[0062] When the heat-conductive sheet 21 is a sheet containing carbon and resin, the resin can exceed 50% by mass relative to the total mass of the heat-conductive sheet 21, or can be 50% by mass or less. That is, as long as there is no major obstacle to heat conduction, the heat-conductive sheet 21 can be based on resin or not. As the resin, for example, a thermoplastic resin can be preferably used. As the thermoplastic resin, a resin with a high melting point such that it does not melt when conducting heat from a heat source is preferably used. For example, polyphenylene sulfide (PPS), polyether ether ketone (PEEK), polyamideimide (PAI), aromatic polyamide (aramid fiber), etc. can be preferably selected. In the state before forming the heat-conductive sheet 21, the resin is dispersed in the gaps of the carbon filler in a granular or fibrous form, for example. In addition to the carbon filler and resin, as a filler for further improving heat conduction, Al2O3, AlN, or diamond can also be dispersed in the heat-conductive sheet 21. Alternatively, an elastomer softer than the resin can be used instead of the resin. The heat-conductive sheet 21 can also be a sheet that replaces carbon as described above or contains metal and / or ceramic together with carbon. As the metal, a metal with relatively high thermal conductivity such as aluminum, copper, or an alloy containing at least one of them can be selected. In addition, as the ceramic, a ceramic with relatively high thermal conductivity such as Al2O3, AlN, cBN, hBN, etc. can be selected.

[0063] The heat-conductive sheet 21 can have excellent or poor electrical conductivity. The thermal conductivity of the heat-conductive sheet 21 is preferably 10 W / mK or more. In this embodiment, the heat-conductive sheet 21 is preferably a graphite film and is made of a material with excellent thermal conductivity and electrical conductivity. The heat-conductive sheet 21 is preferably a sheet with excellent bendability (or flexibility), and its thickness is not limited. It is preferably 0.02 to 3 mm, more preferably 0.03 to 0.5 mm. However, the thermal conductivity of the heat-conductive sheet 21 decreases in the thickness direction as its thickness increases, but the heat transfer amount increases with its thickness. Therefore, it is preferable to determine its thickness by comprehensively considering the strength, flexibility, and thermal conductivity of the sheet.

[0064] (3) Buffer member

[0065] An important function of the buffer member 22 is ease of deformation and resilience. The resilience depends on elastic deformability. Ease of deformation is a characteristic required to follow the shape of the heat source. Especially when accommodating a semi-solid such as a lithium-ion battery or a content with a liquid state in a battery cell with an easily deformable package, the design dimensions are mostly irregular shapes or the dimensional accuracy cannot be improved. Therefore, it is important to maintain the ease of deformation of the buffer member 22 and the resilience for the follow-up force.

[0066] In the present embodiment, the buffer member 22 is a cylindrical buffer member having a hollow portion 23 in the longitudinal direction of the heat dissipation member 20. Even when the heat source in contact with the heat conduction sheet 21 is uneven, the buffer member 22 enables good contact between the heat conduction sheet 21 and the heat source. Furthermore, the hollow portion 23 facilitates the deformation of the buffer member 22, contributes to the weight reduction of the heat dissipation structure 1, and also has the function of improving the contact between the heat conduction sheet 21 and the heat source. The buffer member 22 also functions as a protective member to prevent the heat conduction sheet 21 from being damaged due to the load applied to the heat conduction sheet 21. In this embodiment, the buffer member 22 is a member having a lower thermal conductivity than the heat conduction sheet 21. In addition, in this embodiment, the hollow portion 23 is formed in a circular cross-sectional shape, but the cross-sectional shape of the hollow portion 23 is not limited to a circle, and may be, for example, a polygon, an ellipse, a semi-circle, a substantially polygon with rounded corners, etc. In addition, the hollow portion 23 may be composed of a plurality of hollow portions such as two hollow portions having a semi-circular cross-sectional shape obtained by dividing a circular cross-sectional shape into two parts vertically or horizontally. Furthermore, the buffer member 22 may be a solid shape without the hollow portion 23.

[0067] The buffer member 22 is preferably configured to include thermosetting elastomers such as silicone rubber, polyurethane rubber, isoprene rubber, ethylene propylene rubber, natural rubber, ethylene propylene diene monomer rubber (EPDM), nitrile butadiene rubber (NBR), or styrene butadiene rubber (SBR); thermoplastic elastomers such as polyurethane-based, ester-based, styrene-based, olefin-based, butadiene-based, fluorine-based, or a composite thereof. The buffer member 22 is preferably made of a material having high heat resistance such that it can maintain its shape without melting or decomposing due to the heat transferred in the heat conduction sheet 21. In this embodiment, the buffer member 22 is more preferably made of a material in which silicone is impregnated in a polyurethane-based elastomer or made of silicone rubber. In order to slightly increase its thermal conductivity, the buffer member 22 may also be formed by dispersing fillers represented by particles of Al2O3, AlN, cBN, hBN, diamond, etc. in rubber. The buffer member 22 may or may not contain air bubbles in addition to containing air bubbles inside. In addition, the "buffer member" refers to an elastically deformable member that is flexible and can conform to the surface of the heat source, and in this sense, it can also be replaced by a "rubber-like elastomer". Furthermore, as a deformation example of the buffer member 22, instead of using the above rubber-like elastomer, metal can be used. For example, the buffer member 22 may be made of spring steel. Moreover, as the buffer member 22, a helical spring may be arranged. In addition, a metal wound in a spiral shape can be made into spring steel and arranged as a buffer member on the annular back surface of the heat conduction sheet 21. In addition, the buffer member 22 can also be composed of a sponge or a solid material (a material that is not a porous structure like a sponge) formed of resin, rubber, etc.

[0068] (4) Support plate

[0069] The support plate 10 is preferably a plate-shaped member made of metal. The support plate 10 is more preferably made of a material with relatively high thermal conductivity such as aluminum, copper, or an alloy containing at least one of them. However, the support plate 10 may also contain resin and / or ceramic, or may be made of resin and / or ceramic instead of the above-mentioned metal. As the resin and ceramic, for example, the same materials as those constituting the aforementioned heat conduction sheet 21 can be cited.

[0070] The support plate 10 preferably includes: a support substrate 11 having a plurality of groove portions 15 for supporting the heat dissipation member 20; and a bottom plate 12. The support substrate 11 preferably includes: a plurality of groove portions 15 arranged on the surface facing the heat source along a direction perpendicular to the length direction of the heat dissipation member 20 ( Figure 2 the left-right direction); and a plurality of cutout portions 18 arranged on the surface facing the bottom plate 12 along a direction perpendicular to the length direction (refer to Figure 7 described later). The groove portion 15 is a curved groove portion that opens on the heat dissipation member 20 side (heat source side) and is recessed in the thickness direction ( Figure 2 the up-down direction). The cutout portion 18 is preferably a groove portion that opens on the bottom plate 12 side and is cut into a rectangular shape in the thickness direction ( Figure 2 the up-down direction). The cutout portion 18 is preferably formed to penetrate along the length direction ( Figure 2 the depth direction of the paper surface in the figure). The bottom plate 12 is preferably a flat plate-shaped member joined to the surface of the support substrate 11 where the cutout portion 18 is formed. By joining the support substrate 11 and the bottom plate 12, the support plate 10 forms a through path 17 that penetrates the support plate 10 in the length direction through the cutout portion 18 and the bottom plate 12. The through path 17 is a member that serves as a flow path 43 for allowing the cooling medium 45 to flow in the length direction. It should be noted that the size and shape of the cutout portion 18 are not particularly limited as long as they are at least large enough to allow the cooling medium 45 to flow. In addition, the number of cutout portions 18 provided in the heat dissipation structure 1 is not particularly limited. In addition, the support plate 10 may also be integrally formed with the support substrate 11 and the bottom plate 12. In addition, the cooling medium 45 may be replaced with a "cooling member" or a "coolant". The cooling medium 45 is not limited to cooling water and is interpreted to also include organic solvents such as liquid nitrogen and ethanol. The cooling medium 45 is not limited to a liquid in the case of being used for cooling and may also be a gas or a solid. In addition, since the "support plate" is a plate member that transfers heat from the heat dissipation member 20 to the cooling medium to cool the heat source, it may also be renamed a "cooling plate".

[0071] The heat dissipation member 20 is pressed by the heat source and is flattened in the vertical direction, that is, in the direction from the heat source toward the flow path 43 through which the cooling medium 45 flows. When the heat dissipation member 20 is hardly flattened, there is a possibility that the adhesion between the heat conduction sheet 21 and the heat source or the like becomes low. In order to reduce this risk, when the heat dissipation member 20 is appropriately compressed in the vertical direction, its thickness is at least 80% of the pipe diameter (=equivalent circular diameter: D) of the heat dissipation member 20. The groove portion 15 is formed so that its depth T is less than the equivalent circular diameter D of the heat dissipation member 20. The groove portion 15 is preferably formed so that its depth T is at least 80% (0.8D) or less of the pipe diameter of the heat dissipation member 20 (refer to Figure 2 a magnified view of a part C). In this embodiment, the groove portion 15 is formed so that its depth T is 80% (0.8D) of the pipe diameter of the heat dissipation member 20. Here, the depth T of the groove portion 15 is the length from the surface of the support substrate 11 facing the heat source to the bottom of the groove portion 15. By forming the groove portion 15 in this way, the heat source can be reliably brought into contact with the heat dissipation member 20, and the heat dissipation member 20 can be compressed to at least an appropriate thickness when compressed in the above-mentioned vertical direction.

[0072] In addition, the groove portion 15 is formed so that its radius of curvature R2 is larger than the radius of curvature R1 (=0.5D) of the heat dissipation member 20. By forming the groove portion 15 in this way, when the heat dissipation member 20 is pressed by the heat source and flattened, the heat dissipation member 20 can be deformed into a substantially elliptical shape along the curved surface of the groove portion 15 (refer to Figure 2 a magnified view of a part C). Therefore, in the heat dissipation structure 1, for example, compared with the case where the radius of curvature R2 of the groove portion 15 is smaller than the radius of curvature R1 of the heat dissipation member 20, or the case where the support plate 10 does not have the groove portion 15, the contact area between the heat dissipation member 20 and the support plate 10 when the heat dissipation member 20 is pressed by the heat source and flattened becomes larger. In addition, the groove portion 15 is preferably configured so that the length L2 in its length direction is longer than the length L1 in the length direction of the heat dissipation member 20 (refer to Figure 3 ). By configuring it in this way, even when the heat dissipation member 20 expands and contracts in its length direction due to the press from the heat source, the support plate 10 can reliably support the heat dissipation member 20. However, the support plate 10 may also be configured so that the length L2 in the length direction of the groove portion 15 is the same as the length L1 in the length direction of the heat dissipation member 20. It should be noted that the number of groove portions 15 provided in the heat dissipation structure 1 is not particularly limited as long as it is at least the same as or more than the number of heat dissipation members 20. For example, it can be the same as the number of heat dissipation members 20 or more than the number of heat dissipation members 20.

[0073] (5) Thermal conductive oil

[0074] The heat-conductive oil preferably contains silicone oil and a heat-conductive filler. The heat-conductive filler has a higher heat conductivity than the silicone oil and contains one or more of metals, ceramics, or carbon. The heat-conductive sheet 21 microscopically has gaps (holes or recesses). Usually, air exists in these gaps, which may have an adverse effect on the heat conductivity. The heat-conductive oil fills these gaps and exists instead of air, having the function of improving the heat conductivity of the heat-conductive sheet 21.

[0075] The heat-conductive oil is disposed on the surface of the heat-conductive sheet 21, at least on the surface where the heat source contacts the heat-conductive sheet 21. In this application, the "oil" of the heat-conductive oil refers to a non-water-soluble combustible substance that is liquid or semi-solid at normal temperature (any temperature in the range of 20 to 25 °C). The term "oil" can also be replaced with "grease" or "wax". The heat-conductive oil is an oil that does not become an obstacle to heat conduction when heat is transferred from the heat source to the heat-conductive sheet 21. The heat-conductive oil can be a hydrocarbon-based oil or silicone oil. The heat-conductive oil preferably contains silicone oil and a heat-conductive filler. The heat-conductive filler has a higher heat conductivity than the silicone oil and contains one or more of metals, ceramics, or carbon.

[0076] The silicone oil is preferably composed of molecules with a linear structure having a siloxane bond of 2000 or less. The silicone oil is roughly divided into ordinary silicone oil and modified silicone oil. As ordinary silicone oil, examples include dimethyl silicone oil, methylphenyl silicone oil, and methylhydrogen silicone oil. As modified silicone oil, examples include reactive silicone oil and non-reactive silicone oil. Reactive silicone oil includes various silicone oils such as amino-modified type, epoxy-modified type, carboxyl-modified type, methanol-modified type, methacrylic acid-modified type, mercapto-modified type, and phenol-modified type. Non-reactive silicone oil includes various silicone oils such as polyether-modified type, methylstyryl-modified type, alkyl-modified type, higher fatty acid ester-modified type, hydrophilic special-modified type, higher fatty acid-containing type, and fluorine-modified type. The silicone oil is an oil with excellent heat resistance, cold resistance, viscosity stability, and heat conductivity. Therefore, it is particularly suitable as the heat-conductive oil coated on the surface of the heat-conductive sheet 21 and interposed between the heat source and the heat-conductive sheet 21.

[0077] The heat-conductive oil preferably contains, in addition to the oil component, a heat-conductive filler composed of one or more of metals, ceramics, or carbon. As metals, examples include gold, silver, copper, aluminum, beryllium, tungsten, etc. As ceramics, examples include alumina, aluminum nitride, cubic boron nitride, hexagonal boron nitride, etc. As carbon, examples include diamond, graphite, diamond-like carbon, amorphous carbon, carbon nanotubes, etc.

[0078] The heat conductive oil is preferably disposed not only between the heat source and the heat conductive sheet 21 but also between the heat conductive sheet 21 and the housing of the battery described later. The heat conductive oil can be applied to the entire surface of the heat conductive sheet 21 or a part of the heat conductive sheet 21. The method of causing the heat conductive oil to exist on the heat conductive sheet 21 is not particularly limited and may be any method such as spraying using a sprayer, coating using a brush, or dipping the heat conductive sheet 21 in the heat conductive oil. It should be noted that the heat conductive oil is not an essential component for the heat dissipation structure 1 or the battery described later, but is an additional component that can be appropriately provided. The same applies to the following embodiments.

[0079] In a state where the plurality of heat dissipation members 20 of the heat dissipation structure 1 are supported by the groove portion 15, the heat dissipation structure 1 is arranged on the support plate 10 in a direction perpendicular to its longitudinal direction. The groove portion 15 is a curved groove portion that is open on the side of the heat dissipation member 20 and recessed in the thickness direction, and is formed such that its radius of curvature R2 is larger than the radius of curvature R1 of the heat dissipation member 20 and its depth T is smaller than the circular conversion diameter D of the heat dissipation member 20. Thus, even when the lower ends of the plurality of heat sources are uneven, the contact between the heat conductive sheet 21 and the lower ends becomes good. In order to achieve high heat transfer efficiency, it is preferable to dissipate heat uniformly from each of the plurality of heat sources so that the temperatures of the plurality of heat sources are uniform. For this purpose, it is preferable to arrange the plurality of heat dissipation members 20 such that the number of heat dissipation members 20 in contact with each heat source is uniform. The heat dissipation structure 1 preferably sets the number and position of the groove portions 15 in the support plate 10 in consideration of the sizes of the plurality of heat sources, and sets the number of heat dissipation members 20. By designing the heat dissipation structure 1 in this way, the plurality of heat dissipation members 20 are positioned on the support plate 10. Therefore, the heat dissipation structure 1 can improve the uniformity of heat dissipation of each of the plurality of heat sources. In addition, the heat dissipation structure 1 can be positioned by the groove portion 15 provided in the support plate 10 without connecting the plurality of heat dissipation members 20 with a wire or the like, and can improve the production efficiency. In addition, the heat dissipation structure 1 has a structure in which each heat dissipation member 20 winds the heat conductive sheet 21 in a spiral shape on the outer side surface of the buffer member 22, so that the deformation of the buffer member 22 is not excessively restricted. In addition, the plurality of heat dissipation members 20 are not limited to being arranged such that the distances between the heat dissipation members 20 are equal. That is, the plurality of groove portions 15 are not limited to being arranged such that the distances of the groove portion rolls are equal.

[0080] (Second Embodiment)

[0081] Next, the heat dissipation structure of the second embodiment will be described. The same reference numerals are given to the parts common to the previous embodiments, and the repeated description will be omitted.

[0082] Figure 4 In the same perspective view Figure 2 shows the heat dissipation structure of the second embodiment.

[0083] The heat dissipation structure 1a according to the second embodiment has a structure similar to that of the heat dissipation structure 1 according to the first embodiment, but is different from the heat dissipation structure 1 according to the first embodiment in that a support plate 10a is provided instead of the support plate 10. In addition, the structure of the heat dissipation structure 1a other than the support plate 10a is the same as that of the heat dissipation structure 1 according to the first embodiment, so detailed description thereof is omitted.

[0084] The support plate 10a is preferably a member manufactured by integral molding, which is different from the support plate 10 of the first embodiment manufactured by joining the support substrate 11 and the bottom plate 12. The support plate 10a includes: a plurality of groove portions 15 disposed on a surface facing the heat source along a direction perpendicular to the length direction of the heat dissipation member 20 ( Figure 4 the left-right direction); and a through path 17a disposed along a direction perpendicular to the length direction. The through path 17a penetrates the support plate 10a along the length direction ( Figure 4 the depth direction of the paper surface in the figure) to be formed. The through path 17a, similar to the through path 17 of the first embodiment, is a member that functions as a flow path 43 for the cooling medium 45 to flow along the length direction. In addition, in this embodiment, the through path 17a is formed in a circular cross-sectional shape, but the cross-sectional shape of the through path 17a is not limited to a circle, and may be, for example, a polygon, an ellipse, a semi-circle, a substantially polygon with rounded corners at the vertices, etc. In addition, the through path 17a may be composed of a plurality of through paths such as two through paths with a circular cross-sectional shape divided into two upper and lower or left and right. In addition, the size and position of the through path 17a are not particularly limited as long as they are at least of a size and position that can allow the cooling medium 45 to flow. In addition, the number of through paths 17a provided in the heat dissipation structure 1 is not particularly limited. In addition, since the material of the support plate 10a and the structure of the groove portion 15 are the same as those of the support plate 10 of the first embodiment, detailed description thereof is omitted. The heat dissipation structure 1a configured in this way also has the same effect as the first embodiment.

[0085] 2. Manufacturing method of heat dissipation structure

[0086] Next, an example of a preferred manufacturing method of the heat dissipation structure 1 of the first embodiment will be described.

[0087] Figure 5 A diagram for explaining the manufacturing process of the heat dissipation member constituting the heat dissipation structure. Figure 6 A diagram for explaining the manufacturing process of the support plate constituting the heat dissipation structure of the first embodiment.

[0088] First, an example of a preferred manufacturing method of the heat dissipation member 20 constituting the heat dissipation structure 1 will be described. First, a buffer member 22 having a hollow portion 23 is formed (refer to Figure 5 a) of). Next, an adhesive is applied to the outer side surface of the buffer member 22. Next, after the strip-shaped heat conduction sheet 21 is wound around the outer side surface of the buffer member 22 in a spiral shape, if there is a portion of the heat conduction sheet 21 protruding from both ends of the buffer member 22, the protruding portion is cut or cut together with the buffer member 22 (refer to Figure 5 b and c) of). Finally, a heat conductive oil is applied to the surface of the heat conduction sheet 21. It is also possible to fix the heat conduction sheet 21 without interposing an adhesive between the buffer member 22 and the heat conduction sheet 21. In this case, the buffer member 22 in a state before complete curing is prepared, and the strip-shaped heat conduction sheet 21 is wound around its outer side surface. After that, the buffer member 22 is heated to be completely cured, and the heat conduction sheet 21 is fixed to the outer side surface of the buffer member 22.

[0089] The cutting process for cutting the portion of the heat conduction sheet 21 protruding from both ends of the buffer member 22 and the coating process for applying the heat conductive oil are not limited to being performed at the above timing. For example, the cutting process may be performed after the coating process.

[0090] Next, an example of a preferred manufacturing method of the support plate 10 constituting the heat dissipation structure 1 will be described. First, a support substrate 11 and a bottom plate 12 are prepared (refer to Figure 6 d) of). The support substrate 11 is preferably manufactured by cutting, extrusion molding, etc. The support substrate 11 is formed such that the radius of curvature R2 of the groove portion 15 is larger than the radius of curvature R1 of the heat dissipation member 20 and the depth T of the groove portion 15 is smaller than the circular conversion diameter D of the heat dissipation member 20 (refer to Figure 2 ). Next, the support substrate 11 and the bottom plate 12 are joined by welding or the like to manufacture the support plate 10 (refer to Figure 6 e) of). At this time, the support substrate 11 and the bottom plate 12 are joined such that the cutout portion 18 provided in the support substrate 11 faces the bottom plate 12.

[0091] The heat dissipation structure 1 is manufactured by respectively disposing a plurality of heat dissipation members 20 manufactured by the above manufacturing method on a plurality of groove portions 15 provided in the support plate 10 manufactured by the above manufacturing method. In this case, it is preferable that the plurality of heat dissipation members 20 are fixed in a state of being inclined with respect to the horizontal plane on the surface of the support plate 10 having the grooves 15, and roll on the inclined surface from the upstream side of the inclined surface, so as to be respectively disposed in the plurality of groove portions 15. The heat dissipation structure 1 manufactured in this way can dispose the plurality of heat dissipation members 20 in the plurality of groove portions 15 only by rolling on the inclined surface of the support plate 10 fixed in an inclined manner. Therefore, without connecting the plurality of heat dissipation members 20 with wires or the like, the plurality of heat dissipation members 20 can be easily positioned on the support plate 10, and an improvement in productivity can be achieved. In addition, the heat dissipation structure 1 may also dispose the plurality of heat dissipation members 20 on the support substrate 11 before joining the support substrate 11 and the bottom plate 12. In this case, the heat dissipation structure 1 is manufactured by joining the support substrate 11 on which the plurality of heat dissipation members 20 are disposed to the bottom plate 12.

[0092] The heat dissipation structure 1a according to the second embodiment is manufactured by respectively disposing a plurality of heat dissipation members 20 manufactured by the above manufacturing method in a plurality of groove portions 15 provided in a support plate 10a manufactured by machining or extrusion molding or the like. In this case, it is preferable that the plurality of heat dissipation members 20 are fixed in a state of being inclined with respect to the horizontal plane on the surface of the support plate 10a having the grooves 15, and roll on the inclined surface from the upstream side of the inclined surface, so as to be respectively disposed in the plurality of groove portions 15. The support plate 10a is formed in the same manner as the support plate 10, such that the radius of curvature R2 of the groove portion 15 is larger than the radius of curvature R1 of the heat dissipation member 20, and the depth T of the groove portion 15 is smaller than the circular conversion diameter D of the heat dissipation member 20. The heat dissipation structure 1a manufactured in this way can easily position the plurality of heat dissipation members 20 on the support plate 10a without connecting the plurality of heat dissipation members 20 with wires or the like, and an improvement in productivity can be achieved.

[0093] An example of a preferable manufacturing method of a modified example of the heat dissipation structure 1 will be described. In this modified example, except for replacing the heat dissipation member 20 constituting the above heat dissipation structure 1 with a heat dissipation member 20a, it is manufactured by the same manufacturing method as the above heat dissipation structure 1, so a detailed description thereof is omitted. Hereinafter, a preferable manufacturing method of the heat dissipation member 20a will be described.

[0094] Figure 7 A diagram for explaining a preferable manufacturing process of a modified example of the heat dissipation member constituting the heat dissipation structure.

[0095] First, a strip-shaped laminated sheet 28 is manufactured. In the manufacture of the strip-shaped laminated sheet 28, the heat conduction sheet 21 and the buffer member 22 are preferably fixed using an adhesive. Next, the strip-shaped laminated sheet 28 is made to travel in one direction while being wound into a spiral shape to manufacture a long strip-shaped heat dissipation member 20a. As a manufacturing method in which no adhesive is interposed between the heat conduction sheet 21 and the buffer member 22, the following method can be exemplified. For example, in an uncured state where the buffer member 22 is not completely cured, the heat conduction sheet 21 is pasted on the buffer member 22. Then, the buffer member 22 is completely cured by heating.

[0096] Alternatively, after winding the strip-shaped laminated sheet 28 into a spiral shape, both ends of the laminated sheet 28 may be cut to trim the shape. Finally, a heat conductive oil is applied to the surface of the heat conduction sheet 21. The heat dissipation member 20a has a hollow portion 23a that penetrates in the longitudinal direction thereof. The hollow portion 23a is different from the heat dissipation member 20 in the above-described embodiment in that it also penetrates in the direction of the outer side surface of the heat dissipation member 20a. In this way, the buffer member 22 is disposed inside the heat conduction sheet 21, and the heat conduction sheet 21 and the buffer member 22 have a form of integrally traveling in one direction in a spiral shape. Since the entire heat dissipation member 20a is spiral, it is easier to expand and contract in the longitudinal direction of the heat dissipation member 20a than the above-described heat dissipation member 20.

[0097] In addition, the heat dissipation structure 1a may include the heat dissipation member 20a instead of the heat dissipation member 20. In this case, the heat dissipation structure 1a can be manufactured by the same manufacturing method as the above-described heat dissipation structure 1a except that the heat dissipation member 20 is replaced with the heat dissipation member 20a.

[0098] 3. Battery

[0099] Next, the battery of the present embodiment will be described.

[0100] Figure 8 A longitudinal sectional view of a battery including a heat dissipation structure is shown. Here, the "longitudinal sectional view" refers to a view obtained by vertically cutting from the upper opening surface inside the battery case to the bottom.

[0101] In this embodiment, the battery 40 is, for example, a battery for an electric vehicle and includes a plurality of battery cells 50. The battery 40 includes a bottomed frame 41 that is open on one side. The frame 41 is preferably made of aluminum or an aluminum-based alloy. The battery cells 50 are disposed inside the frame 41 at 44. Electrodes (not shown) project above the battery cells 50. The plurality of battery cells 50 are preferably forced together from both sides within the frame 41 by screws or the like in the compressing direction, and thus are closely adhered to each other (not shown). The battery cells 50 are disposed within the frame 41 in such a manner that a heat dissipation structure 1 is sandwiched between the battery cells 50 and the bottom 42 of the frame 41. On the bottom 42 side of the heat dissipation structure 1, there is provided a flow path 43 (penetrating path 17) through which cooling water, which is an example of a cooling medium 45, flows.

[0102] The battery 40 includes one or two or more battery cells 50 as heat sources inside the frame 41. A plurality of heat dissipation members 20 included in the heat dissipation structure 1 are interposed between the battery cells 50 and the cooling medium 45. In the battery 40 having such a structure, the battery cells 50 transfer heat to the cooling medium 45 flowing in the flow path 43 (penetrating path 17) through the heat dissipation members 20, and heat is effectively removed by water cooling.

[0103] In a state where the battery cells 50 are disposed inside the frame 41 (see Figure 8 ), the heat dissipation structure 1 is compressed in the thickness direction of the heat dissipation structure 1 between the battery cells 50 and the bottom 42. As a result, heat from the battery cells 50 is easily transferred to the heat conduction sheet 21, the support plate 10, the flow path 43, and the cooling medium 45. Further, when the heat dissipation structure 1 is compressed in its thickness direction by the battery cells 50, the heat dissipation structure 1 is compressed to a position where the length in the thickness direction of the heat dissipation member 20 becomes the depth T of the groove portion 15. That is, the heat dissipation member 20 is not compressed to a position where the length in its thickness direction is smaller than the depth T of the groove portion 15. Therefore, even if the heat dissipation member 20 is compressed in this thickness direction (vertical direction) due to the pressing from the battery cells 50, it is possible to suppress the contact between the battery cells 50 and the support plate 10 and further compression of the heat dissipation member 20 compared to the depth T of the groove portion 15. The depth T of the groove portion 15 is preferably a thickness of 80% of the converted diameter D of the heat dissipation member 20 (0.8D). Further, since the heat dissipation structure 1 includes the support plate 10, an operator can mount the heat dissipation structure 1 on the battery 40 by holding the support plate 10, and workability is improved. In addition, the battery 40 may include the aforementioned heat dissipation structure 1a instead of the heat dissipation structure 1.

[0104] 4. Other Embodiments

[0105] As described above, the preferred embodiments of the present invention have been described, but the present invention is not limited thereto, and various modifications can be made for implementation.

[0106] Figure 9 They respectively represent a cross-sectional view when placed horizontally in such a manner that the side surface of the battery cell contacts the heat dissipation structure, a partial enlarged view thereof, and a partial cross-sectional view when the battery cell expands during charge and discharge.

[0107] In the foregoing first embodiment, the situation where the battery cell 50 is vertical and the heat dissipation structure 1 contacts its lower end has been described, but the arrangement manner of the battery cell 50 is not limited thereto. As Figure 9 shown, the battery cell 50 can also be arranged in such a manner that the side surface of the battery cell 50 contacts each heat dissipation member 20, 20a of the heat dissipation structure 1. The temperature of the battery cell 50 rises during charging and discharging. If the container of the battery cell 50 itself is formed of a material rich in flexibility, the side surface of the battery cell 50 may expand in particular. Even in such a case, as Figure 9 shown, each heat dissipation member 20, 20a constituting the heat dissipation structure 1 can also deform in accordance with the shape of the outer surface of the battery cell 50, so that the heat dissipation performance can be maintained at a high level during charge and discharge. In addition, similarly in the above-described second embodiment, the battery cell 50 can also be arranged in such a manner that the side surface of the battery cell 50 contacts each heat dissipation member 20, 20a of the heat dissipation structure 1a.

[0108] In addition, the support plates 10, 10a may also be formed with one or more positioning holes through which the positioning pins provided on the frame 41 (such as the bottom 42, etc.) of the battery 40 can be inserted. The positioning hole is a hole through which the positioning pin protruding from the bottom 42 of the battery 40 can be inserted. By inserting the positioning pin into the positioning hole, the positioning of the battery 40 and the heat dissipation structures 1, 1a becomes easy. In addition, the shapes and positions of the positioning hole and the positioning pin are not particularly limited.

[0109] In addition, in the above-described first embodiment, the support plate 10 is composed of the support substrate 11 and the bottom plate 12, but the support plate 10 may not have the bottom plate 12. That is, the support plate 10 may be composed only of the support substrate 11. In this case, when the support plate 10 is disposed on the battery 40, the support plate 10 may be disposed in such a manner that the surface on the side of the cutout portion 18 of the support plate 10 is placed on the bottom 42 of the frame 41. Thereby, the flow path 43 for allowing the cooling medium 45 to flow in the length direction can be formed by the cutout portion 18 and the bottom 42.

[0110] In addition, the forms of the support plates 10, 10a are not particularly limited, as long as they have a plurality of groove portions 15 that support a plurality of heat dissipation members 20, 20a at least along a direction perpendicular to the length direction of the heat dissipation members 20, 20a, for example, they may not have the through paths 17, 17a. In this case, in order to allow the cooling medium 45 to flow on the bottom 42 of the frame 41, the battery 40 preferably has one or more water cooling pipes 43.

[0111] In addition, the heat dissipation member 20 may also not form the hollow portion 23 in the buffer member 22. In this case, the heat dissipation member 20 has a structure in which the buffer member 22 is filled in the hollow portion of the spiral heat conduction sheet 21. The hollow portion may be formed by at least the winding structure of the heat conduction sheet 21 among the heat conduction sheet 21 and the buffer member 22, and thus may not be formed in the buffer member 22.

[0112] In addition, as long as the heat conduction sheet 21 included in the heat dissipation member 20 is shaped to cover at least the outer side surface of the buffer member 22, it may not be in a shape that travels while being wound into a spiral. For example, the heat dissipation member 20 may also be in a form in which the outer side surface of the buffer member 22 is covered with a single planar heat conduction sheet 21.

[0113] In addition, the spiral buffer member 22 in the heat dissipation member 20a is not limited to having the same width as the heat conduction sheet 21, and may be larger or smaller than the width of the heat conduction sheet 21.

[0114] In addition, the heat source includes not only the battery unit 50, but also all objects that generate heat, such as a circuit board, an electronic device main body, etc. For example, the heat source may also be electronic components such as a capacitor and an IC chip. Similarly, the cooling medium 45 may be not only water for cooling, but also an organic solvent, liquid nitrogen, or a cooling gas. In addition, the heat dissipation structures 1 and 1a may also be disposed in structures other than the battery 40, such as electronic devices, household appliances, and power generation devices.

[0115] In addition, the multiple constituent elements of the above-described respective embodiments can be freely combined except in cases where they cannot be combined with each other. For example, the heat dissipation structure 1a may also be provided in the battery 40.

[0116] Industrial Applicability

[0117] The heat conduction member of the present invention can be used, for example, in various electronic devices such as automobiles, industrial robots, power generation devices, PCs, and household electrical appliances, in addition to automotive batteries. In addition, the battery of the present invention can be used in household rechargeable batteries, batteries for electronic devices such as PCs, etc., in addition to automotive batteries.

Claims

1. A heat dissipation structure, characterized in that the heat dissipation structure includes a plurality of heat dissipation members for enhancing heat dissipation from a heat source and a support plate for supporting the plurality of heat dissipation members, the heat dissipation members include: a plurality of buffer members having a hollow or solid shape; and a heat conduction sheet for transferring heat from the heat source, covering the outer side surface of the buffer members, the support plate has a plurality of groove portions for supporting the heat dissipation members along a direction perpendicular to the length direction of the heat dissipation members, the groove portions are curved groove portions that are open on the heat dissipation member side and recessed in the thickness direction, and are formed such that their radius of curvature is greater than the radius of curvature of the heat dissipation members and their depth is less than the circular conversion diameter of the heat dissipation members.

2. The heat dissipation structure according to claim 1, wherein The support plate has at least one or more flow paths for allowing a cooling medium to flow along the length direction.

3. The heat dissipation structure according to claim 2, wherein, The flow paths are through paths that penetrate the support plate.

4. The heat dissipation structure according to any one of claims 1 to 3, characterized in that, The support plate is a plate-shaped member made of metal.

5. The heat dissipation structure according to any one of claims 1 to 3, characterized in that The heat dissipation members are cylindrical members having a hollow portion along the length direction.

6. The heat dissipation structure according to claim 5, characterized in that the buffer members are cylindrical buffer members having the hollow portion along the length direction, the heat conduction sheet is wound around the outer side surface of the cylindrical buffer member in a spiral shape toward the length direction.

7. The heat dissipation structure according to claim 5, wherein The heat conduction sheet and the buffer members have a form of integrally advancing in a spiral shape in one direction.

8. The heat dissipation structure according to any one of claims 1 to 3, characterized in that, There is heat conductive oil on the surface of the heat conduction sheet, and the heat conductive oil is used to enhance the heat conductivity from the heat source in contact with the surface of the heat conduction sheet to the surface.

9. The heat dissipation structure according to claim 8, wherein The heat conductive oil contains silicone oil and heat conductive fillers, the heat conductivity of the heat conductive fillers is higher than that of the silicone oil, and the heat conductive fillers include one or more of metal, ceramic, or carbon.

10. A battery, which includes one or two or more battery cells as heat sources in a housing, and the heat dissipation structure according to any one of claims 1 to 9 is provided between the battery cells and the housing.

Images