Cooling structure

Abstract

A cooling structure according to the present invention is provided with a flow path forming member that forms a flow path for circulating a refrigerant. In a bottom part inner wall of the flow path forming member, a cooling fin installation section is provided, separated from a side part inner wall of the flow path forming member, the cooling fin installation section being provided with at least one cooling fin projecting from the bottom part inner wall to inside the flow path. At least one obstacle projecting from the side part inner wall to inside the flow path is provided on the side part inner wall of the flow path forming member.

Description

[Technical Field]

[0001] The present disclosure relates to a cooling structure. [Background technology]

[0002] In recent years, with the increase in heat generation from heat-generating elements, development of cooling structures with high cooling efficiency has been progressing. For example, vehicles equipped with motors, such as hybrid vehicles and electric vehicles, are equipped with drive means for driving the motor. The drive means is composed of a power module including multiple power semiconductors such as IGBTs (insulated gate bipolar transistors), electronic components such as capacitors, and bus bars that electrically connect these electronic components. When driving a motor, a large current may flow through the bus bars that connect the power semiconductors, capacitors, and other electronic components. In this case, the drive means generates heat due to switching loss, resistance loss, and other factors, making it desirable to efficiently cool the drive means.

[0003] In a cooling structure such as a water jacket through which a coolant flows to cool a heat generating body, cooling fins are usually installed inside (see, for example, Patent Document 1). The cooling fins are arranged to obstruct the flow of the coolant, increase the flow rate of the heat dissipation part, and improve cooling performance. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] International Publication No. 2011 / 132736 Summary of the Invention [Problem to be solved by the invention]

[0005] In a cooling structure such as a water jacket having cooling fins provided therein, it is desirable to further improve the cooling efficiency. In view of such circumstances, the present disclosure relates to providing a cooling structure having excellent cooling efficiency. [Means for solving the problem]

[0006] Means for solving the above problems include the following aspects. <1> a flow path forming member that forms a flow path for circulating a coolant; a cooling fin installation section in which at least one cooling fin protruding from the bottom inner wall toward the inside of the flow path is provided is provided on the bottom inner wall of the flow path forming member, the cooling fin installation section being spaced apart from the side inner wall of the flow path forming member; The cooling structure includes at least one obstacle provided on an inner side wall of the flow path forming member, the obstacle protruding from the inner side wall toward the inside of the flow path. <2> the flow path has a narrow portion where the width of the flow path is narrowed, The cooling fin installation section is provided in a narrow portion of the flow path. <1> The cooling structure according to claim 1. <3> The present invention has at least one combination of an obstacle A, which is one of the at least one obstacle, and a cooling fin B, which is one of the at least one cooling fins and is closest to the obstacle A, that satisfies the relationship of the following formula: <1> or <2> The cooling structure according to claim 1. Formula:a≧b a: Length of obstacle A in the width direction of the flow path b: The minimum distance between the cooling fin B and the inner side wall of the flow path forming member <4> The following relationship is satisfied: <1> ~ <3> The cooling structure according to any one of claims 1 to 5. Formula:c≧d c: average length of the at least one obstacle in the width direction of the flow path d: minimum distance between the at least one cooling fin and the inner side wall of the flow path forming member <5> When the flow path is observed from the protruding direction of the cooling fin, in a section formed by extending the cooling fin installation section in the width direction to the side inner wall of the flow path forming member, the at least one cooling fin and the at least one obstacle are arranged so that any straight line parallel to the longitudinal direction of the flow path intersects with at least one selected from the group consisting of the at least one cooling fin and the at least one obstacle. <1> ~ <4> The cooling structure according to any one of claims 1 to 5. <6> The average length of the at least one cooling fin in the width direction of the flow path is 0.5 mm to 20.0 mm. <1> ~ <5> The cooling structure according to any one of claims 1 to 5. <7> The average length of the at least one obstacle in the width direction of the flow channel is 0.25 mm to 10.0 mm. <1> ~ <5> The cooling structure according to any one of claims 1 to 5. <8> The at least one cooling fin is provided in plurality in the cooling fin installation section. <1> ~ <7> The cooling structure according to any one of claims 1 to 5. <9> the at least one obstacle is provided in a plurality of areas on the side inner wall of the flow path forming member corresponding to the cooling fin installation section; <1> ~ <8> The cooling structure according to any one of claims 1 to 5. [Effects of the Invention]

[0007] According to the present disclosure, a cooling structure having excellent cooling efficiency is provided. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 2 is a cross-sectional view showing a main part of a cooling structure according to one embodiment. [Figure 2] 3 is a schematic diagram showing the configuration of a flow path forming member of a cooling structure according to one embodiment. FIG. [Figure 3] 3 is a schematic diagram showing the configuration of a flow path forming member of a cooling structure according to one embodiment. FIG. [Figure 4] 3 is a schematic diagram showing the configuration of a flow path forming member of a cooling structure according to one embodiment. FIG. [Figure 5]3 is a schematic diagram showing the configuration of a flow path forming member of a cooling structure according to one embodiment. FIG. [Figure 6] 3 is a schematic diagram showing the configuration of a flow path forming member of a cooling structure according to one embodiment. FIG. [Figure 7] FIG. 2 is a schematic view of a side inner wall of a flow path forming member of a cooling structure according to one embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, modes for carrying out embodiments of the present disclosure will be described in detail. However, the embodiments of the present disclosure are not limited to the following embodiments. In the following embodiments, components (including element steps, etc.) are not essential unless otherwise specified. The same applies to numerical values ​​and their ranges, and they do not limit the embodiments of the present disclosure.

[0010] In the present disclosure, the term "process" includes not only a process that is independent of other processes, but also a process that cannot be clearly distinguished from other processes as long as the purpose of the process is achieved. In the present disclosure, numerical ranges indicated using "to" include 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 one numerical range may be replaced with the upper or lower limit value of another numerical range described in stages. When embodiments of the present disclosure are described with reference to the drawings, the configuration of the embodiment is not limited to the configuration shown in the drawings. Furthermore, the size of components in each drawing is conceptual, and the relative size relationships between components are not limited to this. Furthermore, in each drawing, components having substantially the same function are assigned the same reference numerals, and redundant descriptions may be omitted.

[0011] In the present disclosure, the bottom inner wall of the flow path forming member refers to two opposing surfaces among the surfaces surrounding the flow path in an area including at least the cooling fin installation section, and a cooling fin is provided protruding from at least one of the surfaces. In the present disclosure, the side inner wall of the flow path forming member refers to any surface connecting the two bottom inner walls among the surfaces surrounding the flow path in an area including at least the cooling fin installation section. In this disclosure, the "longitudinal direction" of a cooling structure, a flow path forming member, or a flow path refers to a direction parallel to the direction of travel of the refrigerant in the flow path (here, the direction of travel of the refrigerant when the presence of cooling fins, obstacles, etc. is not taken into consideration). In this disclosure, the "width direction" of a cooling structure, a flow path forming member, or a flow path refers to a direction perpendicular to the longitudinal direction. In the present disclosure, the cross section of a flow path refers to a cross section obtained by cutting the flow path in the width direction from one bottom inner wall of the flow path forming member to the other bottom inner wall.

[0012] ≪Cooling structure≫ The cooling structure of the present disclosure comprises: a flow path forming member that forms a flow path for circulating a coolant; a cooling fin installation section in which at least one cooling fin protruding from the bottom inner wall toward the inside of the flow path is provided is provided on the bottom inner wall of the flow path forming member, the cooling fin installation section being spaced apart from the side inner wall of the flow path forming member; The cooling structure is such that at least one obstacle is provided on the inner side wall of the flow path forming member, the obstacle protruding from the inner side wall toward the inside of the flow path. In conventional cooling structures in which no obstacles are provided on the side surfaces of the flow path forming member, the refrigerant flows largely along the wall surfaces of the flow path forming member, and the refrigerant does not flow easily into the compartments where the cooling fins are located, resulting in reduced cooling efficiency. In the cooling structure of the present disclosure, obstacles are provided on the side surfaces of the flow path forming member, which inhibit the flow of the refrigerant along the side surfaces, making it easier for the refrigerant to flow into the compartments where the cooling fins are located, which is thought to improve cooling efficiency.

[0013] Hereinafter, a cooling structure according to the present disclosure will be described with reference to the drawings. However, the embodiments of the present disclosure are not limited to those illustrated in the drawings. 1 is a cross-sectional view in the width direction of a cooling structure 10 in one embodiment of the cooling structure of the present disclosure. Note that Fig. 1 is a cross-sectional view of the cooling structure 10 cut along line AA shown in Fig. 2. The cooling structure 10 shown in FIG. 1 includes a flow path forming member 14 having a substantially rectangular cross section and forming a flow path 12 for circulating a coolant. The flow path 12 is surrounded by an upper bottom inner wall 16, which corresponds to one of a pair of opposing bottom inner walls of the flow path forming member 14, and a lower bottom inner wall 18, which corresponds to the other inner wall, as well as side inner walls 20 and 22, which connect the upper bottom inner wall and the lower bottom inner wall 18.

[0014] In the cooling structure 10, a plurality of cooling fins 24 are provided to protrude substantially perpendicularly from the upper bottom inner wall 16 of the flow path forming member 14 toward the inside of the flow path 12. The protruding directions of the plurality of cooling fins 24 are all substantially parallel to one another. When the flow path forming member 14 provided with the cooling fins 24 is manufactured using a mold, making the protruding directions of the plurality of cooling fins 24 substantially parallel makes it easier to pull the cooling fins 24 out of the mold. This makes it easier to manufacture the flow path forming member 14 provided with the cooling fins 24 using a mold.

[0015] 1, the cooling fins 24 and the obstacles 36 are indicated by dotted lines in a cross section in the width direction (a cross section when the cooling structure 10 is cut along line BB in FIG. 2) at a location different from the cross section shown in FIG. 1. The multiple cooling fins 24 are arranged in a substantially straight line in the width direction of the flow path 12. The cooling fins 24 arranged on line AA in FIG. 2 and the cooling fins 24 and obstacles 36 arranged on line BB in FIG. 2 are arranged in a positional relationship where they are offset from each other in the width direction of the flow path 12, and are configured to obstruct the flow of refrigerant that moves straight in the longitudinal direction of the flow path 12.

[0016] A bus bar 26, which is the object to be cooled, is fixed to the base of the cooling fin 24 with a bolt 28 and a nut 30. The nut 30 has a nut body 32 and a heat diffusion member 34 provided on the side of the nut body 32 opposite to the side where the bolt 28 is inserted. The heat diffusion member 34 is a plate-like member that is integrated with the nut body 32. The bus bar 26 is connected to electronic components (not shown) such as power semiconductors and capacitors.

[0017] The entire heat diffusion member 34 of the nut 30 and the portion of the nut body 32 opposite to the side where the bolt 28 is inserted are embedded in the flow path forming member 14. Note that the heat diffusion member 34 is not limited to being embedded in the flow path forming member 14, and may be joined to the flow path forming member 14, for example, joined to the outer wall of the flow path forming member 14. For example, the heat diffusion member 34 may be joined to the flow path forming member 14 using a resin-metal joining technique using laser roughening.

[0018] When a current flows through the bus bar 26, the bus bar 26 itself generates heat due to resistance loss. The bus bar 26 is also connected to electronic components (not shown), and heat generated by these electronic components when a current is passed through the bus bar 26 is diffused through the bus bar 26. Therefore, the bus bar 26 is prone to becoming hot.

[0019] Heat generated from the bus bar 26 itself and heat diffused through the bus bar 26 is transferred via the bolt 28 and the nut body 32 to the portion of the heat diffusion member 34 that is integrated with the nut body. Because the heat diffusion member 34 is a plate-like object, the heat transferred to the heat diffusion member 34 is diffused in the plane direction of the heat diffusion member 34, allowing the heat to be diffused over a wide area.

[0020] The heat diffusion member 34 is disposed at the base of the cooling fins 24, and the heat diffused to the heat diffusion member 34 reaches the base of the cooling fins 24. The heat that reaches the base of the cooling fins 24 moves from the base of the cooling fins 24 to the tip of the cooling fins 24 through the cooling fins 24. At this time, the heat is transferred from the cooling fins 24 to the refrigerant flowing through the flow paths 12. In this manner, the object to be cooled, such as the bus bar 26, is cooled.

[0021] 1, the minimum distance h from the surface of the heat diffusion member 34 on the flow path 12 side to the inner wall of the flow path forming member 14 is preferably 0.3 mm or more from the viewpoint of insulation, more preferably 0.5 mm or more from the viewpoint of formability, and even more preferably 1.5 mm or more. Furthermore, from the viewpoint of cooling efficiency, the minimum distance h is preferably 2.5 mm or less.

[0022] 2 is a schematic diagram of the internal structure of the region where the cooling fins 24 are provided in the cooling structure 10 of FIG. 1, viewed from the protruding direction of the cooling fins 24. To make it easier to understand the positional relationship between the cooling fins 24 and the thermal diffusion member 34, illustration of the bus bars 26 and the like is omitted in FIG. 2. Also, to make it easier to understand the positional relationship between the cooling fins 24 and the thermal diffusion member 34, a section (hereinafter referred to as the thermal diffusion section 34a) corresponding to the installation position of the thermal diffusion member 34 is indicated by a two-dot chain line.

[0023] 2, seven cooling fins 24 are provided within the thermal diffusion section 34a. That is, the inner wall of the upper bottom of the flow path forming member 14 corresponding to the thermal diffusion member 34 is defined as the cooling fin installation section 34b. The number of cooling fins 24 provided within the thermal diffusion section 34a is not particularly limited. Note that the positional relationship between the thermal diffusion section 34a and the cooling fin installation section 34b is not limited to the configuration shown in FIG. 2; for example, the cooling fins 24 may be provided outside the range of the thermal diffusion section 34a, or the thermal diffusion section 34a may be located outside the cooling fin installation section 34b.

[0024] Obstacles 36 are provided on the side inner walls 20 and 22 of the flow path forming member 14 so as to protrude from the side inner walls 20 and 22 into the flow path 12. This causes the refrigerant to change direction and flow toward the cooling fins 24 instead of flowing linearly along the side inner walls 20 and 22 of the flow path forming member 14.

[0025] Each component of the cooling structure of the present disclosure will be described below.

[0026] <Flow path forming member> The cooling structure includes a flow path forming member for circulating a coolant. The material of the flow path forming member is not particularly limited. For example, the material of the flow path forming member may be a resin. Examples of the resin include polyethylene resin, polypropylene resin (PP), composite polypropylene resin (PPC), polyphenylene sulfide resin (PPS), polyphthalamide resin (PPA), polybutylene terephthalate resin (PBT), epoxy resin, phenol resin, polystyrene resin, polyethylene terephthalate resin, polyvinyl alcohol resin, vinyl chloride resin, ionomer resin, polyamide resin, acrylonitrile-butadiene-styrene copolymer resin (ABS), and polycarbonate resin.

[0027] The resin constituting the flow path forming member may contain an inorganic filler, such as glass, silica, alumina, zircon, magnesium oxide, calcium silicate, calcium carbonate, potassium titanate, silicon carbide, silicon nitride, boron nitride, beryllia, zirconia, etc. Aluminum hydroxide, zinc borate, etc. may also be used as a flame-retardant inorganic filler.

[0028] (flow path) The shape of the flow path formed by the flow path forming member is not particularly limited. The cross-sectional shape of the flow path may be rectangular, circular, elliptical, or a polygon other than rectangular. From the viewpoint of ease of manufacturing the flow path forming member, a rectangular shape is preferable. Of the flow path, a region including the cooling fin installation region is preferably rectangular. Each inner wall forming the flow path may be flat or curved.

[0029] The width and length of the flow path are not particularly limited and can be set appropriately depending on the size, shape, etc. of the object to be cooled.

[0030] In one embodiment, the flow path may have a narrow portion where the width of the flow path is narrowed, and a cooling fin may be provided in the narrow portion of the flow path. Figure 3 is a schematic diagram showing the arrangement of the flow path forming member and the flow path shape in one embodiment of a flow path forming member in which a cooling fin is provided in the narrow portion. When the flow path has a narrow portion, the amount of refrigerant flowing through the cooling fin installation section increases, improving cooling efficiency. When the flow path has a narrow portion, if no obstacles are provided on the side inner wall of the flow path forming member, the refrigerant will more easily flow along the side inner wall. In the cooling structure of the present disclosure, the provision of obstacles on the side inner wall prevents the refrigerant from flowing linearly along the side inner wall, improving cooling efficiency.

[0031] (Cooling fin installation area) A cooling fin installation section is provided on the bottom inner wall of the flow path forming member, spaced apart from the side inner wall of the flow path forming member, and has at least one cooling fin protruding from the bottom inner wall into the flow path. The cooling fin installation section is preferably a section corresponding to a region where the object to be cooled or a thermal diffusion section connected to the object to be cooled contacts the flow path forming member. In the present disclosure, the cooling fin installation section means a section defined as follows: When observing the flow path forming member from the protruding direction of the cooling fins, a line passing through the point of the cooling fin closest to the side inner wall of the flow path forming member and parallel to the longitudinal direction of the flow path is drawn on both sides of the flow path forming member. A line passing through the most upstream point of the cooling fin located most upstream in the flow path and parallel to the width direction of the flow path is drawn, and a line passing through the most downstream point of the cooling fin located most downstream in the flow path and parallel to the width direction of the flow path is drawn. The rectangular area enclosed by the four lines drawn is the cooling fin installation section. Figure 2 shows the cooling fin installation section 34b obtained by the above procedure.

[0032] The number of cooling fin installation sections in the flow path is not particularly limited, and can be set appropriately depending on the number of objects to be cooled.

[0033] The number of cooling fins in a cooling fin installation section is not particularly limited. From the viewpoint of cooling efficiency, multiple cooling fins may be provided. For example, two or more, ten or more, or twenty or more cooling fins may be provided in a cooling fin installation section. Furthermore, 100 or less, 90 or less, or 80 or less cooling fins may be provided in a cooling fin installation section. Two to 100, 10 to 90, or 20 to 80 cooling fins may be provided per cooling fin installation section.

[0034] When multiple cooling fins are provided in the cooling fin installation section, the arrangement of each cooling fin is not particularly limited. In one aspect, multiple cooling fins may be arranged in the width direction of the flow path. In one aspect, multiple cooling fins may be arranged in the longitudinal direction of the flow path. In one aspect, multiple cooling fins may be arranged in the width direction and longitudinal direction of the flow path. In one aspect, in order to prevent the flow of refrigerant parallel to the longitudinal direction of the flow path, multiple cooling fins arranged in the width direction of the flow path may be arranged in multiple rows in the longitudinal direction, with the rows being offset from each other in the width direction.

[0035] The shape of the cooling fins is not particularly limited, and may be a cylinder, an elliptical cylinder, a rectangular pillar, a cone, a pyramid, or the like. The shape of the tip of the cooling fin may be flat, hemispherical, conical, pyramidal, or the like.

[0036] The size of the cooling fins is not particularly limited. For example, from the viewpoint of strength, the average length of the cooling fins in the width direction of the flow path is preferably 0.5 mm or more, more preferably 1.0 mm or more, and even more preferably 1.5 mm or more. Furthermore, from the viewpoint of cooling efficiency, the average length is preferably 20.0 mm or less, more preferably 15.0 mm or less, even more preferably 3.0 mm or less, and particularly preferably 2.0 mm or less. From these viewpoints, the average length is preferably 0.5 mm to 20.0 mm, more preferably 1.0 mm to 15.0 mm, even more preferably 1.5 mm to 3.0 mm, and particularly preferably 1.5 mm to 2.0 mm. The average length of the flow path of the cooling fins in one cooling fin installation section is the arithmetic mean value of the width direction lengths of all the cooling fins at their base portions (i.e., the portions where the cooling fins intersect with the bottom inner wall) of all the cooling fins in one cooling fin installation section.

[0037] The length of the cooling fins in the protruding direction can be set appropriately based on the size of the flow path, etc. For example, from the viewpoint of formability, the average length of the cooling fins in the protruding direction is preferably 50 mm or less, more preferably 30 mm or less. Furthermore, from the viewpoint of cooling efficiency, the average length is preferably 10 mm or more, more preferably 30 mm or more. The average length of the cooling fins in the protruding direction is the arithmetic mean value of the lengths from the base (i.e., the part where the cooling fin meets the bottom inner wall) to the tip of the cooling fin for all the cooling fins in one cooling fin installation section.

[0038] The material of the cooling fin is not particularly limited. The material of the cooling fin may be metal from the viewpoint of thermal conductivity, or resin from the viewpoint of ease of processing. Examples of resin include the resins exemplified as materials for the flow path forming member. The resin may or may not contain an inorganic filler exemplified as materials for the flow path forming member. The material of the cooling fin may be the same as or different from at least one material selected from the group consisting of the flow path forming member and the obstacle. The cooling fin may be made of a metal core material coated with resin. Coating the metal core material with resin ensures insulation and can suppress metal corrosion, etc. It is preferable that the resin coats the entire surface of the metal core material. From the viewpoint of improving cooling efficiency, it is preferable that one end of the core material is connected to a thermal diffusion unit connected to the object to be cooled.

[0039] The surface roughness Ra of the portion of the cooling fin that comes into contact with the refrigerant may be 10 μm or more, 50 μm or more, or 100 μm or more. If the surface roughness of the portion of the cooling fin that comes into contact with the refrigerant is 10 μm or more, the thermal emissivity of the cooling fin increases, and heat tends to be transferred from the cooling fin to the refrigerant more efficiently. If the surface roughness Ra of the portion of the cooling fin that comes into contact with the refrigerant is 100 μm or more, the surface area of ​​the cooling fin increases, and heat tends to be transferred from the cooling fin to the refrigerant more efficiently. The surface roughness Ra of the portion of the cooling fin that comes into contact with the refrigerant may be 500 μm or less from the viewpoint of processability, etc. In the present disclosure, the surface roughness Ra refers to a value measured based on JIS B0601:2013.

[0040] Methods for making the surface roughness Ra of the cooling fin at the portion that comes into contact with the refrigerant 10 μm or more include a method in which the surface of a mold used to mold the flow path forming member is given irregularities corresponding to the surface roughness of the cooling fin, and then the cooling fin is molded from resin, and a method in which the surface of the cooling fin is adjusted to the desired surface roughness by mechanical processing such as machining, blasting, or laser processing.

[0041] (Obstacles) In a region corresponding to the cooling fin installation section, the side inner wall of the flow path forming member is provided with at least one obstacle protruding from the side inner wall into the flow path, the obstacle being provided so as to prevent the refrigerant from flowing linearly along the side inner wall of the flow path and to change the direction of the refrigerant flow.

[0042] The shape of the obstacle is not particularly limited, and the cross-sectional shape of the obstacle when observed from the protruding direction of the cooling fin may be semicircular, arcuate, partially circular, rectangular, or a polygon other than a rectangle. In observing the cross section of the flow path, the obstacle may be provided from one bottom inner wall to the other bottom inner wall of the flow path forming member, or may be provided on a part of the one bottom inner wall to the other bottom inner wall. From the viewpoint of efficiently blocking the flow of the refrigerant, it is preferable that the obstacle be provided from one bottom inner wall to the other bottom inner wall of the flow path forming member.

[0043] The size of the obstacles is not particularly limited. For example, the average length of the obstacles in the width direction of the flow channel may be 0.25 mm or more, 0.5 mm or more, 0.8 mm or more, or 1.0 mm or more. From the viewpoint of cooling efficiency, the average length of the obstacles in the width direction of the flow channel may be 10.0 mm or less, 7.0 mm or less, or 5.0 mm or less. The length of the obstacles in the width direction of the flow channel may be 0.25 mm to 10.0 mm, 0.5 mm to 10.0 mm, 0.8 mm to 7.0 mm, or 1.0 mm to 5.0 mm. The average length of the obstacles in the width direction of the flow channel may be within the above range. The average widthwise length of the obstacles is the arithmetic mean of the widthwise lengths of all obstacles present in the area corresponding to one cooling fin installation section. Here, the "area corresponding to the cooling fin installation section" refers to the area defined as follows: When observing the flow path from the direction in which the cooling fins of the flow path forming member protrude, the cooling fin installation section is extended in the widthwise direction of the flow path forming member to obtain a straight line where it intersects with the side inner wall (the two obtained straight lines are shown by bold lines in Figure 6). Next, when observing the flow path from the direction in which the obstacles protrude, the obtained straight line is moved from one bottom of the side inner wall of the flow path forming member to the other bottom, and the area through which the obtained straight line passes is defined as the "area corresponding to the cooling fin installation section." Figure 7 shows a schematic diagram of one embodiment of the side inner wall observed from the direction in which the obstacles extend. In Figure 7, the bold line corresponds to the obtained straight line. The area surrounded by the bold and dashed lines in Figure 7 is the "area corresponding to the cooling fin installation section." Figure 7 shows that two obstacles exist in the "area corresponding to the cooling fin installation section" for one side inner wall. The average widthwise length of the obstacle is the average widthwise length of the obstacles present in the "area corresponding to the cooling fin installation section" on the pair of side inner walls, but the average widthwise length of the obstacles present on one of the side inner walls may also be within the above range. The average length of the obstacle in the width direction of the flow passage may be determined so that the minimum distance between the cooling fin and the inner side wall of the flow passage forming member satisfies a specific relationship described below.

[0044] The number of obstacles is not particularly limited. In one aspect, a plurality of obstacles may be provided in an area of ​​the inner side wall of the flow passage forming member that corresponds to the cooling fin installation section.

[0045] The material of the obstacle is not particularly limited. From the viewpoint of ease of processing, the material of the obstacle may be a resin. Examples of the resin include the resins exemplified in the material of the flow path forming member. The resin may or may not contain an inorganic filler exemplified in the material of the flow path forming member. The material of the obstacle may be the same as or different from at least one material selected from the group consisting of the flow path forming member and the cooling fin. The obstacle may be molded together with the flow path forming member, or may be manufactured separately from the flow path forming member and integrated with the flow path forming member.

[0046] (Arrangement of cooling fins and obstacles) In one embodiment, the cooling structure may have at least one combination of an obstacle A, which is one of the at least one obstacle, and a cooling fin B, which is one of the at least one cooling fins and is closest to the obstacle A, satisfying the following formula: Formula:a≧b a: The width of the flow path of obstacle A b: Minimum distance between cooling fin B and the inner side wall of the flow path forming member

[0047] 4, for example, in the case of obstacle A, which is one of the four obstacles, and cooling fin B, which is one of the seven cooling fins and is closest to obstacle A, the length a of obstacle A in the width direction of the flow path and the minimum distance b between cooling fin B and the inner side wall of the flow path forming member satisfy the relationship a ≥ b. This configuration tends to prevent the refrigerant from flowing linearly along the inner side wall of the flow path forming member, thereby improving cooling efficiency.

[0048] In one embodiment, the cooling structure may satisfy the following relationship: Formula:c≧d c: average length of at least one obstacle across the width of the flow channel d: minimum distance between at least one cooling fin and the inner side wall of the flow path forming member

[0049] 5, for example, the average value c of the widthwise lengths c1 to c4 of the four obstacles and the minimum distance d between the seven cooling fins and the inner side wall of the flow path forming member satisfy the relationship c≧d. This configuration tends to prevent the refrigerant from flowing linearly along the inner side wall of the flow path forming member, thereby improving cooling efficiency. The "average widthwise length of at least one obstacle in the flow path" in the above c refers to the average widthwise length of obstacles present in the "region corresponding to the cooling fin installation section" on the pair of side inner walls, as described above, and the "side inner walls" in the above d refers to the pair of side inner walls. The average widthwise length of obstacles present on one side inner wall and the minimum distance between the flow path forming member on the same side inner wall and the side inner wall may also satisfy the above relationship. For example, in FIG. 5, the average values ​​c' and d of c3 and c4 may satisfy the relationship c'≧d.

[0050] In one aspect, when the flow path is observed from the protruding direction of the cooling fin, in a section formed by extending the cooling fin installation section in the width direction to the side inner wall of the flow path forming member, the at least one cooling fin and the at least one obstacle may be arranged so that any straight line parallel to the longitudinal direction of the flow path intersects with at least one selected from the group consisting of the at least one cooling fin and the at least one obstacle.

[0051] 6, in section S1, which is formed by extending the cooling fin installation section in the width direction to the side inner wall of the flow path forming member, any straight line drawn parallel to the longitudinal direction of the flow path intersects with at least one selected from the group consisting of a cooling fin and an obstacle. This prevents the refrigerant from flowing in a straight line, increases the chances of the refrigerant coming into contact with the cooling fin, and tends to improve cooling efficiency.

[0052] <Refrigerant> The type of coolant flowing through the flow path is not particularly limited. Examples of the coolant include liquids such as water and organic solvents, and gases such as air. Water used as the coolant may contain components such as antifreeze.

[0053] <Cooled object> Examples of the object to be cooled include electronic components such as power semiconductors and capacitors, in addition to the bus bars exemplified in the description of Fig. 1. When the object to be cooled is an electronic component, it is preferable to provide a cooling fin at the location of the cooling structure where the electronic component is placed.

[0054] The object to be cooled may be cooled via a thermal diffusion unit exemplified in the description of Fig. 1. The material of the thermal diffusion unit may be a metal or alloy such as aluminum, iron, copper, gold, silver, or stainless steel. The thermal diffusion unit may be mesh-shaped, punched metal, or the like, from the viewpoint of suppressing the load on the cooling structure due to the difference in thermal expansion coefficient between the material constituting the flow path forming member and the cooling fins and the metal constituting the thermal diffusion unit.

[0055] [Method for manufacturing cooling structure] The method for manufacturing the cooling structure is not particularly limited, and can be any of the usual molding methods for resin molded bodies, such as injection molding, die slide injection molding, blow molding, compression molding, transfer molding, extrusion molding, and cast molding. Since high positional accuracy is sometimes required for manufacturing the cooling structure, die slide injection molding is preferred. The cooling structure may also be manufactured by combining die slide injection molding with other molding methods, such as insert molding.

[0056] [Uses of cooling structure] The cooling structure can be widely used for cooling heat-generating bodies, and is particularly effective for cooling power modules equipped with multiple power semiconductors, electronic components such as capacitors, and bus bars that electrically connect these electronic components in vehicles equipped with motors such as hybrid vehicles and electric vehicles.

[0057] The disclosure of Japanese Patent Application No. 2021-011481 is incorporated herein by reference in its entirety. All documents, patent applications, and technical standards described herein are incorporated by reference into this specification to the same extent as if each individual document, patent application, and technical standard was specifically and individually indicated to be incorporated by reference. [Explanation of symbols]

[0058] 10 Cooling structure 12 Flow path 14 Flow path forming member 16 Upper bottom inner wall 18 Lower bottom inner wall 20 Side inner wall 22 Side inner wall 24 Cooling fins 26 Busbar 28 volts 30 nuts 32 Nut body 34 Heat diffusion material 34a Thermal diffusion section 34b Cooling fin installation section 36 Obstacles A Obstacle A B Cooling fin B a) Width of obstacle A b Minimum distance between cooling fin B and the inner side wall of the flow path forming member c1 to c4: Length of obstacles in the width direction of the flow path S1 A section in which the cooling fin installation section is extended in the width direction to the side inner wall of the flow path forming member

Claims

1. a flow path forming member that forms a flow path for circulating a coolant; the flow path has a narrow portion where the width of the flow path is narrowed, a cooling fin installation section in which at least one cooling fin is provided on a bottom inner wall of the flow path forming member in a narrow width portion of the flow path, the cooling fin installation section being spaced apart from a side inner wall of the flow path forming member and protruding from the bottom inner wall toward the inside of the flow path; The cooling structure further comprises at least one obstacle provided on an inner side wall of the flow passage forming member at a narrow portion of the flow passage, the obstacle protruding from the inner side wall toward the inside of the flow passage.

2. 2. The cooling structure according to claim 1, comprising at least one combination of an obstacle A, which is one of the at least one obstacle, and a cooling fin B, which is one of the at least one cooling fins and is closest to the obstacle A, satisfying the relationship of the following formula: Formula: a≧b a: Length of obstacle A in the width direction of the flow path b: Minimum distance between the cooling fin B and the inner side wall of the flow path forming member

3. The cooling structure according to claim 1 or 2, which satisfies the following formula: Formula: c≧d c: average length of the at least one obstacle in the width direction of the flow path d: minimum distance between the at least one cooling fin and the inner side wall of the flow path forming member

4. 4. The cooling structure according to claim 1, wherein, when the flow path is observed from the protruding direction of the cooling fin, in a section formed by extending the cooling fin installation section in the width direction to the side inner wall of the flow path forming member, the at least one cooling fin and the at least one obstacle are arranged so that any straight line parallel to the longitudinal direction of the flow path intersects with at least one selected from the group consisting of the at least one cooling fin and the at least one obstacle.

5. The cooling structure according to any one of claims 1 to 4, wherein the average length of the at least one cooling fin in the width direction of the flow path is 0.5 mm to 20.0 mm.

6. The cooling structure according to any one of claims 1 to 4, wherein an average length of the at least one obstacle in the width direction of the flow path is 0.25 mm to 10.0 mm.

7. The cooling structure according to any one of claims 1 to 6, wherein a plurality of the at least one cooling fins are provided in the cooling fin installation section.

8. The cooling structure according to any one of claims 1 to 7, wherein the at least one obstacle is provided in a plurality of areas on the side inner wall of the flow path forming member corresponding to the cooling fin installation section.

9. A cooling structure described in any one of claims 1 to 8, wherein the material of the flow path forming member includes resin.

10. A cooling structure described in any one of claims 1 to 9, wherein the material of the flow path forming member includes resin, and the cooling structure further comprises a heat diffusion member joined to or embedded in the flow path forming member.

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