Cooling structure

Abstract

To provide a resin-made cooling structure which is excellent in cooling efficiency.SOLUTION: A cooling structure 10 has a resin-made flow channel formation member 14 forming a flow channel 12 circulating a refrigerant, a bus bar 26 having a terminal part 28A, a terminal part 28B and a connection part 30 for connecting the terminal part 28A and the terminal part 28B, and a fastening part 36A and a fastening part 36B which are provided on an outer wall surface of the flow channel formation member 14 and fix the terminal part 28A and the terminal part 28B of the bus bar 26 to the flow channel formation member 14, wherein the fastening part 36A and the fastening part 36B include a bolt 32A or a bolt 32B, and a nut 34A or a nut 34B which is screwed with the bolt 32A or the bolt 32B and is embedded in the flow channel formation member 14, when the inside of the flow channel 14 is observed from a refrigerant flow direction, a side opposite to a side where the bolt 32A or the bolt 32B is mounted of the nut 34A or the nut 34B projects into the flow channel 12 in a state of covered with the flow channel formation member 14.SELECTED DRAWING: Figure 2

Description

[Technical field]

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

[0002] Vehicles equipped with motors, such as hybrid vehicles and electric vehicles, are equipped with a drive means for driving the motor. The drive means is composed of a power module having a plurality of 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 bar that connects electronic components such as power semiconductors and capacitors. When a large current flows through the bus bar, the driving means generates heat due to switching loss, resistance loss, etc., so the driving means needs to be cooled efficiently.

[0003] As a cooling means for cooling the driving means, a heat sink made of a metal such as aluminum or copper is used because of its high thermal conductivity (see, for example, Patent Document 1). Also, a terminal block is known in which a nut for fastening a bus bar and a heat sink are integrated with an insulating plate by resin (see, for example, Patent Document 2). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2010-182831 A [Patent Document 2] JP 2012-151038 A Summary of the Invention [Problem to be solved by the invention]

[0005] However, in order to manufacture a metal heat sink, it is necessary to go through complicated manufacturing processes such as extrusion molding, skiving, crimping, etc. Therefore, the cost of a metal heat sink tends to be high. In addition, many steps may be required to incorporate a metal heat sink into a cooling target such as a drive means, etc. Therefore, a cooling method that has excellent cooling efficiency without using a metal heat sink is required.

[0006] One aspect of the present disclosure has been made in consideration of the above-described conventional circumstances, and has an object to provide a resin cooling structure having excellent cooling efficiency. [Means for solving the problem]

[0007] Specific means for achieving the above object are as follows. <1> a flow path forming member made of resin that forms a flow path through which a coolant flows; A bus bar having a plurality of terminal portions and a connecting portion connecting the plurality of terminal portions; a fastening portion provided on an outer wall surface of the flow path forming member and configured to fix the terminal portions of the bus bar to the flow path forming member, The fastening portion includes a bolt and a nut that is screwed with the bolt and embedded in the flow passage forming member, A cooling structure in which, when the inside of the flow path is observed from the direction in which the refrigerant flows, the side of the nut opposite the side to which the bolt is attached protrudes into the flow path and is covered by the flow path forming member. <2> When the inside of the flow path is observed from the direction of flow of the refrigerant, the tip of the bolt reaches into the inside of the flow path. <1> The cooling structure according to claim 1. <3> The outer shape of the nut is a cylinder or a polygonal column. <1> or <2> The cooling structure according to claim 1. <4> The outer peripheral surface of the nut is knurled or serrated. <1> ~ <3> 13. The cooling structure according to claim 12 . <5> The metal constituting the bolt and the nut is copper or a copper-containing alloy. <1> ~ <4> 13. The cooling structure according to claim 12 . Effect of the Invention

[0008] According to one embodiment of the present disclosure, it is possible to provide a resin cooling structure having excellent cooling efficiency. [Brief description of the drawings]

[0009] [Figure 1] FIG. 2 is a plan view of a main part of the cooling structure 10. [Diagram 2] 2 is a cross-sectional view of the cooling structure 10 taken along line AA in FIG. 1. FIG. [Diagram 3] 2 is a diagram showing an end face of the cooling structure 10 taken along line BB in FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, the embodiments for carrying out the present disclosure will be described in detail. However, the present disclosure is not limited to the following embodiments. In the following embodiments, the components (including element steps, etc.) are not essential unless otherwise specified. The same applies to the numerical values ​​and their ranges, and do not limit the present disclosure.

[0011] <Cooling structure> The cooling structure disclosed herein comprises a flow path forming member made of resin that forms a flow path through which a refrigerant flows, a bus bar having a plurality of terminal portions and connecting portions that connect the plurality of terminal portions, and a fastening portion provided on an outer wall surface of the flow path forming member and fixing the plurality of terminal portions of the bus bar to the flow path forming member, wherein the fastening portion includes a bolt and a nut that screws into the bolt and is embedded in the flow path forming member, and when the inside of the flow path is observed from the flow direction of the refrigerant, the side of the nut opposite the side where the bolt is attached protrudes into the flow path and is covered by the flow path forming member. In the cooling structure of the present disclosure, when observing the inside of the flow path from the direction of the refrigerant flow, the side of the nut opposite to the side where the bolt is attached is covered by the flow path forming member and protrudes into the flow path, so that the amount of refrigerant that comes into contact with the nut via the flow path forming member can be increased while ensuring the insulation of the nut. This makes it possible to efficiently transfer heat transferred from the bus bar to the nut to the refrigerant, improving the cooling efficiency of the cooling structure.

[0012] The cooling structure of the present disclosure will be described below with reference to the drawings. Note that the sizes of the members in each drawing are conceptual, and the relative relationship between the sizes of the members is not limited thereto. In addition, members having substantially the same functions are given the same reference numerals throughout the drawings, and duplicated descriptions may be omitted.

[0013] Figures 1 to 3 are diagrams showing the main parts of the cooling structure 10, with Figure 1 showing a plan view of the main parts of the cooling structure 10, Figure 2 showing a cross section of the cooling structure 10 taken along line AA in Figure 1, and Figure 3 showing an end face of the cooling structure 10 taken along line BB in Figure 1. The arrows in Figure 2 indicate the direction of refrigerant flow, and Figure 3 corresponds to a diagram of the inside of the flow path 12 observed from the direction of refrigerant flow. The cooling structure 10 includes a resin flow path forming member 14 that forms a flow path 12 having a substantially rectangular cross section for circulating a refrigerant. The flow path 12 is surrounded by an upper inner wall 16 that corresponds to one of a pair of opposing inner walls, a lower inner wall 18 that corresponds to the other of the pair of opposing inner walls, and a side inner wall 20 and a side inner wall 22 that connect the upper inner wall 16 and the lower inner wall 18.

[0014] Bus bar 26 has terminal portion 28A, terminal portion 28B, and connecting portion 30 that connects terminal portion 28A and terminal portion 28B. Terminal portion 28A is overlapped with terminal portion 28C of another bus bar 38 by fastening portion 36A formed of bolt 32A and nut 34A screwed onto bolt 32A, and is fastened and fixed to the outer wall surface of flow path forming member 14. Terminal portion 28B is overlapped with terminal portion 28D of another bus bar 40 and fastened and fixed to the outer wall surface of flow path forming member 14 by fastening portion 36B formed of bolt 32B and nut 34B screwed onto bolt 32B. The bus bars 38 and 40 are connected to electronic components (not shown) such as power semiconductors and capacitors.

[0015] A portion of nut 34A opposite to the side where bolt 32A is inserted and a portion of nut 34B opposite to the side where bolt 32B is inserted are embedded in the outer wall surface of flow path forming member 14. In addition, as shown in Figures 2 and 3, when the inside of flow path 12 is observed from the flow direction of the refrigerant, the portion of nut 34A opposite to the side where bolt 32A is inserted and the portion of nut 34B opposite to the side where bolt 32B is inserted protrude from upper inner wall 16 into flow path 12 while being covered by flow path forming member 14. The resin thickness in the portions of the nuts 34A and 34B covered with the flow path forming member 14 is preferably 2.5 mm or less, more preferably 2.0 mm or less, and even more preferably 1.5 mm or less, from the viewpoint of improving cooling performance. On the other hand, the resin thickness in the portions of the nuts 34A and 34B covered with the flow path forming member 14 is preferably 0.3 mm or more, more preferably 0.5 mm or more, and even more preferably 1.0 mm or more, in order to ensure the insulation of the nuts 34A and 34B.

[0016] By configuring the portion of nut 34A opposite the side where bolt 32A is inserted and the portion of nut 34B opposite the side where bolt 32B is inserted to protrude into flow path 12 while being covered by flow path forming member 14, it becomes possible to position a portion of nuts 34A and 34B within flow path 12, and the cooling structure 10 can be made low-profile. In the cooling structure 10, the tip portion of the nut 34A on the side opposite to the side where the bolt 32A is inserted, and the tip portion of the nut 34B on the side opposite to the side where the bolt 32B is inserted are configured not to reach the lower inner wall 18, but these tip portions may reach the lower inner wall 18.

[0017] 2 and 3, when the inside of the flow passage 12 is observed from the direction in which the refrigerant flows, the tips of the bolts 32A and 32B reach into the inside of the flow passage 12. As shown in FIG. By having the tips of bolts 32A and 32B reach inside flow path 12, heat transferred from the bus bar to the bolts can be efficiently transferred into flow path 12, further improving the cooling efficiency of cooling structure 10.

[0018] The nuts 34A and 34B may be general-purpose metal nuts, and there is no particular limitation on their shapes. The nuts 34A and 34B may have an outer shape of a cylinder or a polygonal column. Furthermore, the outer circumferential surfaces of the nuts 34A and 34B may be knurled or serrated from the viewpoint of improving the bonding strength between the nuts 34A and 34B and the flow path forming member 14 and from the viewpoint of improving the cooling effect.

[0019] The metal constituting the bus bar is not particularly limited, and examples thereof include copper, a copper-containing alloy, aluminum, etc. The bus bar may be plated with nickel, tin, etc. The metal constituting the bolts and nuts is not particularly limited, and examples thereof include copper, copper-containing alloys, aluminum, iron, etc. The bolts and nuts may be plated with nickel, trivalent chromate, zinc, etc. Generally, the metal constituting the busbar is copper or a copper-containing alloy from the viewpoint of electrical conductivity, and therefore, from the viewpoint of suppressing the occurrence of electrolytic corrosion when a busbar made of copper or a copper-containing alloy is used, the metal constituting the bolt and nut is preferably copper or a copper-containing alloy, and more preferably brass.

[0020] There is no particular limitation on the type of coolant flowing through the flow path 12. 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.

[0021] (Method of manufacturing flow passage forming member) The flow path forming member 14 may be manufactured by any method, and may be manufactured by a method for molding a typical resin molded body, such as injection molding, die slide injection molding, blow molding, compression molding, transfer molding, extrusion molding, cast molding, etc. Since high positional accuracy may be required in the manufacture of the cooling structure, the die slide injection molding is preferred. Furthermore, the portion of the flow passage forming member 14 where the nuts 34A and 34B are embedded may be manufactured separately by insert molding.

[0022] There is no particular limitation on the type of resin constituting the flow path forming member 14. 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), polycarbonate resin, and the like.

[0023] The resin constituting the flow path forming member 14 may contain an inorganic filler. Examples of the inorganic filler include silica, alumina, zircon, magnesium oxide, calcium silicate, calcium carbonate, potassium titanate, silicon carbide, silicon nitride, boron nitride, beryllia, and zirconia. Furthermore, examples of inorganic fillers having a flame retardant effect include aluminum hydroxide and zinc borate.

[0024] (Use of cooling structure) The cooling structure of the present disclosure is effective for cooling bus bars that electrically connect electronic components such as power modules having a plurality of power semiconductors and capacitors in vehicles equipped with motors such as hybrid automobiles and electric automobiles. [Explanation of symbols]

[0025] 10 Cooling structure 12 Flow Path 14 Flow path forming member 16 Upper inner wall 18 Lower inner wall 20, 22 Inner side wall 26, 38, 40 Busbars 28A, 28B, 28C, 28D terminal section 30 Connecting part 32A, 32B Volts 34A, 34B Nut 36A, 36B fastening section

Claims

1. a flow path forming member made of resin that forms a flow path through which a coolant flows; A bus bar having a plurality of terminal portions and a connecting portion connecting the plurality of terminal portions; a fastening portion provided on an outer wall surface of the flow path forming member and configured to fix the terminal portions of the bus bar to the flow path forming member, The fastening portion includes a bolt and a nut that is screwed with the bolt and embedded in the flow passage forming member, A cooling structure in which, when the inside of the flow path is observed from the direction in which the refrigerant flows, the side of the nut opposite the side to which the bolt is attached protrudes into the flow path and is covered by the flow path forming member.

2. 2. The cooling structure according to claim 1, wherein when the inside of the flow passage is observed from the direction in which the coolant flows, a tip of the bolt reaches into the inside of the flow passage.

3. 3. The cooling structure according to claim 1, wherein the nut has an outer shape of a cylinder or a polygonal column.

4. The cooling structure according to any one of claims 1 to 3, wherein the outer peripheral surface of the nut is knurled or serrated.

5. The cooling structure according to any one of claims 1 to 4, wherein the metal constituting the bolt and the nut is copper or a copper-containing alloy.

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