Cooling unit, cooling unit manufacturing method, battery case with cooling unit, and battery for electric vehicle

Abstract

To provide a cooling unit that has a refrigerant flow path formed of resin, but can prevent blockage of the refrigerant flow path and a decrease in refrigerant efficiency caused by molten resin, and a method for manufacturing the same.SOLUTION: A cooling unit 50 for an electric vehicle battery includes a first resin-laminated metal plate having a first metal plate 1 and a first resin layer 2 laminated on one side of the first metal plate, and a second resin-laminated metal plate having a second metal plate 3 and a second resin layer laminated on one side of the second metal plate, which are welded together via the first resin layer and the second resin layer, and a concave surface 9 that becomes a refrigerant flow path 51 of the cooling unit is formed in the first resin layer 2, and no melting marks are observed in the resin 5 that forms the refrigerant flow path 51, in the part of the resin 6 that comes into contact with the metal plate 1 where the shape of the concave surface 9 is reflected.SELECTED DRAWING: Figure 7

Description

[Technical Field]

[0001] The present invention relates to a cooling unit, a method for manufacturing a cooling unit, a battery case with a cooling unit, and a battery for an electric vehicle. [Background technology]

[0002] In electric vehicles that use electricity supplied from batteries as a power source, such as electric vehicles (EVs) and battery-powered trains, thermal management is important to prevent the battery's discharge capacity and lifespan from decreasing. A cooling medium is used to remove heat generated by the battery, and therefore a cooling unit for cooling the battery needs a flow path structure for the cooling medium (refrigerant) to flow (for example, Patent Documents 1-3).

[0003] Patent Document 1 discloses a battery case for an electric vehicle and a manufacturing method thereof. The battery case for an electric vehicle in Patent Document 1 includes a tray having a mounting portion on which a battery is placed and having a groove formed in the bottom of the mounting portion, a closure plate joined to the tray so as to close the groove and define a coolant flow path, and a top cover that seals the mounting portion of the tray.

[0004] Patent Document 2 discloses a battery pack. The pack housing of the battery pack in Patent Document 2 includes a floor panel having a lower surface formed with a coolant channel for supplying or discharging cooling water, and a base plate disposed in a layered manner below the floor panel.

[0005] Patent Document 3 discloses a water-cooled heat sink. In the water-cooled heat sink of Patent Document 3, a flow path structure is formed by interposing a flow path forming plate, which has a long hole that penetrates from the upper surface side to the lower surface side, between an upper cover and a lower cover. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Publication No. 2021-064448 [Patent Document 2] Special Publication No. 2022-545886 [Patent Document 3] Japanese Patent Application Laid-Open No. 2012-64732 Summary of the Invention [Problem to be solved by the invention]

[0007] In the battery case for an electric vehicle disclosed in Patent Document 1, the battery case and cooling unit are joined and integrated using friction stir welding (FSW). In the battery pack disclosed in Patent Document 2, FSW is also used to join the coolant channel and base plate. However, due to technical limitations, FSW cannot be applied to joining surfaces with complex shapes, which limits the shape of the cooling unit.

[0008] In the water-cooled heat sink described in Patent Document 3, the upper cover, lower cover, and flow path forming plate are joined together by brazing. However, brazing requires heating to a temperature close to the melting point of the metal, so it cannot be applied to thin metal plates due to the risk of thermal damage. This not only limits the shape of the cooling unit, but is also disadvantageous for cooling units for electric vehicle batteries, which require lightweight construction.

[0009] The present inventors came up with the idea of ​​forming the refrigerant flow path of the cooling unit out of resin in order to increase the degree of freedom in designing the shape of the cooling unit. For example, as shown in Fig. 1, a resin-made refrigerant flow path 51 can be formed using a resin-laminated metal plate 10 in which a resin layer 2 is laminated on a metal plate 1 having a concave surface 9 formed thereon, and a resin-laminated metal plate 11 in which a resin layer 4 is laminated on a metal plate 3. In addition to the example shown in Fig. 1, a flow path structure can also be formed by bonding the resin-laminated metal plate 10 to a battery case, so forming the refrigerant flow path of the cooling unit out of resin is highly useful.

[0010] However, when the inventors actually produced a prototype cooling unit using a resin-laminated metal sheet, they found that not only the welded portion of the resin layer but also the resin layer forming the refrigerant flow path melted. For example, as shown in Figure 2, if resin 16 in refrigerant flow path 51 melts, refrigerant flow path 51 is partially blocked. This can reduce the cooling efficiency.

[0011] The inventors also investigated a hot plate welding method in which a hot plate is brought into direct contact with the resin surface to melt the resin layer of the resin laminated metal plate, and then the bonding surface is pressed to bond them together. However, with this hot plate welding method, heat is also transferred to the resin on the refrigerant flow path surface, causing the resin layer that forms the refrigerant flow path to melt, resulting in the shape of the flow path structure being distorted.

[0012] Dividing the hot plate into multiple pieces was also considered to reduce the amount of heat transferred from the hot plate. However, when the spacing between the multiple concave surfaces 9, 9 that form the flow paths is narrow, as shown in Figure 3, it is difficult to manufacture the small divided hot plate 41. In addition, arranging the small divided hot plate in a location where the spacing between the concave surfaces is narrow is cumbersome. As a result, dividing the hot plate into multiple pieces limits the size of the refrigerant flow path. This does not increase the degree of freedom in designing the shape of the cooling unit.

[0013] In addition, as shown in Fig. 4, when the hot plate 40 is separated from the resin layer 2 after contact with the resin layer 2, stringiness 42 of the molten resin occurs. If the stringy resin flows into the refrigerant flow path, the refrigerant flow path may be blocked, as shown in Fig. 2.

[0014] The present invention primarily provides a cooling unit that has a refrigerant flow path formed of resin, but can prevent blockage of the refrigerant flow path and a decrease in refrigerant efficiency caused by molten resin, and a method for manufacturing the same. [Means for solving the problem]

[0015] The present invention has the following aspects. [1] A cooling unit for an electric vehicle battery, a first resin-laminated metal plate having a first metal plate and a first resin layer laminated on one surface of the first metal plate, and a second metal plate welded and joined via the first resin layer; a concave surface that serves as a refrigerant flow path of the cooling unit is formed in the first resin layer; A cooling unit, wherein no melting traces are observed in the resin forming the refrigerant flow path at a portion where the shape of the concave surface is reflected and the resin is in contact with the first metal plate. [2] A cooling unit for an electric vehicle battery, a first resin-laminated metal plate having a first metal plate and a first resin layer laminated on one surface of the first metal plate, and a second resin-laminated metal plate having a second metal plate and a second resin layer laminated on one surface of the second metal plate, the first resin layer and the second resin layer being welded and joined together; a concave surface that serves as a refrigerant flow path of the cooling unit is formed in one or both of the first resin layer and the second resin layer; A cooling unit, wherein no melting traces are observed in the resin forming the refrigerant flow path at a portion where the resin comes into contact with the metal plate in a portion where the shape of the concave surface is reflected. [3] The cooling unit according to [2], wherein the first resin layer contains a thermoplastic resin or the second resin layer contains a thermoplastic resin. [4] The cooling unit according to [2] or [3], wherein the first resin layer has a thickness of 0.05 to 0.2 mm, or the second resin layer has a thickness of 0.05 to 0.2 mm. [5] The cooling unit according to any one of [2] to [4], wherein the thermal conductivity of the first resin layer is 0.1 W / m·K or more, or the thermal conductivity of the second resin layer is 0.1 W / m·K or more. [6] A cooling unit described in any one of [2] to [5], wherein the surface of the refrigerant flow path is covered with the first resin layer and the second resin layer so that the refrigerant does not come into contact with the first metal plate and the second metal plate. [7] The cooling unit according to any one of [2] to [6], wherein solidified resin overflows from the end where the first resin-laminated metal plate and the second resin-laminated metal plate are joined. [8] The cooling unit according to any one of [1] to [7], wherein the thickness of the first metal plate is 0.5 to 2.0 mm, or the thickness of the second metal plate is 0.5 to 2.0 mm. [9] A cooling unit according to any one of [1] to [8], wherein the thermal conductivity of the first metal plate is 200 W / m·K or more, or the thermal conductivity of the second metal plate is 200 W / m·K or more.

[10] The cooling unit according to any one of [1] to [9], wherein the specific gravity of the first metal plate is 4.0 or less, or the specific gravity of the second metal plate is 4.0 or less.

[11] The cooling unit according to any one of [1] to

[10] , wherein solidified resin overflows from an end portion where the first resin-laminated metal plate and the second metal plate are joined.

[0016]

[12] A method for manufacturing a cooling unit for an electric vehicle battery, comprising: The method includes joining a first resin-laminated metal plate having a first metal plate and a first resin layer laminated on one surface of the first metal plate to a second metal plate by infrared welding via the first resin layer, The manufacturing method, wherein the first resin layer has a concave surface formed therein, the concave surface serving as a refrigerant flow path for the cooling unit.

[13] A method for manufacturing a cooling unit for an electric vehicle battery, comprising: a first resin-laminated metal plate having a first metal plate and a first resin layer laminated on one surface of the first metal plate, and a second resin-laminated metal plate having a second metal plate and a second resin layer laminated on one surface of the second metal plate, joined together by infrared welding via the first resin layer and the second resin layer; The manufacturing method, wherein a concave surface that serves as a refrigerant flow path of the cooling unit is formed in one or both of the first resin layer and the second resin layer.

[14] A manufacturing method according to

[12] or

[13] , in which the resin layer in the portion where the concave surface is formed when the first resin-laminated metal plate is viewed from the side is joined by infrared welding without irradiating it with infrared rays.

[15] A manufacturing method according to any one of

[12] to

[14] , in which the resin layer adjacent to the concave surface when the first resin-laminated metal plate is viewed from the side is also joined by infrared welding without irradiating it with infrared rays.

[16] The manufacturing method according to any one of

[12] to

[15] , wherein the metal plate in the portion where the shape of the concave surface is not reflected is pressed and joined by infrared welding.

[17] The manufacturing method according to any one of

[13] to

[16] , wherein the first resin layer contains a thermoplastic resin or the second resin layer contains a thermoplastic resin.

[18] The manufacturing method according to any one of

[13] to

[17] , wherein the thickness of the first resin layer is 0.05 to 0.2 mm, or the thickness of the second resin layer is 0.05 to 0.2 mm.

[19] The manufacturing method according to any one of

[13] to

[18] , wherein the thermal conductivity of the first resin layer is 0.1 W / m·K or more, or the thermal conductivity of the second resin layer is 0.1 W / m·K or more.

[20] The manufacturing method according to any one of

[12] to

[19] , wherein the thickness of the first metal plate is 0.5 to 2.0 mm, or the thickness of the second metal plate is 0.5 to 2.0 mm.

[21] The manufacturing method according to any one of

[12] to

[20] , wherein the thermal conductivity of the first metal plate is 200 W / m·K or more, or the thermal conductivity of the second metal plate is 200 W / m·K or more.

[22] The manufacturing method according to any one of

[12] to

[21] , wherein the specific gravity of the first metal plate is 4.0 or less, or the specific gravity of the second metal plate is 4.0 or less.

[0017]

[23] A battery case; a cooling unit attached to the battery case; Equipped with A battery case with a cooling unit for an electric vehicle battery, wherein the cooling unit is the cooling unit according to any one of [1] to

[11] .

[24] a battery module; a battery case that houses the battery module; a cooling unit attached to the battery case; Equipped with The battery for an electric vehicle, wherein the cooling unit is the cooling unit according to any one of [1] to

[11] .

[25] The battery for an electric vehicle according to

[24] , wherein the cooling unit is attached to the outside of the battery case.

[26] The battery for an electric vehicle according to

[24] or

[25] , wherein the cooling unit is attached to the inside of the battery case.

[0018]

[27] A battery case; a cooling unit attached to the battery case; Equipped with the cooling unit includes a first resin-laminated metal plate having a first metal plate and a first resin layer laminated on one surface of the first metal plate; The first resin layer has a concave surface that serves as a refrigerant flow path for the cooling unit, the battery case and the first resin-laminated metal plate are welded and joined via the first resin layer, A battery case with a cooling unit for an electric vehicle battery, in which no melting marks are observed in the resin forming the refrigerant flow path at the portion where the shape of the concave surface is reflected and which comes into contact with the first metal plate.

[28] A battery case with a cooling unit for an electric vehicle battery as described in

[27] , wherein solidified resin overflows from the end where the battery case and the first resin-laminated metal plate are joined.

[29] A battery case with a cooling unit for an electric vehicle battery according to

[27] or

[28] , wherein the first resin layer contains a thermoplastic resin.

[30] The battery case with a cooling unit for an electric vehicle battery according to any one of

[27] to

[29] , wherein the first resin layer has a thickness of 0.05 to 0.2 mm.

[31] The battery case with a cooling unit for an electric vehicle battery according to any one of

[27] to

[30] , wherein the first resin layer has a thermal conductivity of 0.1 W / m·K or more.

[32] The battery case with a cooling unit for an electric vehicle battery according to any one of

[27] to

[31] , wherein the thickness of the first metal plate is 0.5 to 2.0 mm.

[33] The battery case with a cooling unit for an electric vehicle battery according to any one of

[27] to

[32] , wherein the first metal plate has a thermal conductivity of 200 W / m·K or more.

[34] The battery case with a cooling unit for an electric vehicle battery according to any one of

[27] to

[33] , wherein the specific gravity of the first metal plate is 4.0 or less.

[0019]

[35] a battery module; a battery case that houses the battery module; a cooling unit attached to the battery case; Equipped with the cooling unit includes a first resin-laminated metal plate having a first metal plate and a first resin layer laminated on one surface of the first metal plate; a concave surface that serves as a refrigerant flow path of the cooling unit is formed in the first resin layer; the battery case and the first resin-laminated metal plate are welded and joined via the first resin layer, A battery for an electric vehicle, wherein no melting marks are observed in the resin forming the refrigerant flow path at the portion where the shape of the concave surface is reflected and in contact with the first metal plate.

[36] The battery for an electric vehicle according to

[35] , wherein the cooling unit is attached to the outside of the battery case.

[37] The battery for an electric vehicle according to

[35] or

[36] , wherein the cooling unit is attached to the inside of the battery case.

[38] The battery for an electric vehicle according to any one of

[35] to

[37] , wherein solidified resin overflows from the end where the battery case and the first resin-laminated metal plate are joined.

[39] The battery for an electric vehicle according to any one of

[35] to

[38] , wherein the first resin layer contains a thermoplastic resin.

[40] The battery for an electric vehicle according to any one of

[35] to

[39] , wherein the first resin layer has a thickness of 0.05 to 0.2 mm.

[41] The battery for an electric vehicle according to any one of

[35] to

[40] , wherein the first resin layer has a thermal conductivity of 0.1 W / m·K or more.

[42] The battery for an electric vehicle according to any one of

[35] to

[41] , wherein the thickness of the first metal plate is 0.5 to 2.0 mm.

[43] A battery for an electric vehicle according to any one of

[35] to

[0442] , wherein the thermal conductivity of the first metal plate is 200 W / m·K or more.

[44] The battery for an electric vehicle according to any one of

[35] to

[43] , wherein the specific gravity of the first metal plate is 4.0 or less. [Effects of the Invention]

[0020] According to the present invention, there is provided a cooling unit and a manufacturing method thereof that has a refrigerant flow path formed primarily from resin, but can prevent blockage of the refrigerant flow path and a decrease in refrigerant efficiency caused by molten resin. [Brief explanation of the drawings]

[0021] [Figure 1] FIG. 1 is a schematic explanatory diagram of a cooling unit. [Figure 2] FIG. 2 is a schematic cross-sectional view showing an example of a problem with a refrigerant flow path formed of resin. [Figure 3] FIG. 3 is a schematic cross-sectional view showing another example of the problem of a refrigerant flow path formed of resin. [Figure 4] FIG. 4 is a schematic cross-sectional view showing another example of the problem of a refrigerant flow path formed of resin. [Figure 5]FIG. 5 is a side view showing an example of a cooling unit. [Figure 6] FIG. 6 is a side view showing another example of the cooling unit. [Figure 7] FIG. 7 shows an example of a resin cross section of a refrigerant flow path of a cooling unit. [Figure 8] FIG. 8 is a schematic diagram for illustrating an example of irradiating the first resin-clad metal sheet with infrared rays using an infrared light source. [Figure 9] FIG. 9 is a schematic diagram for illustrating an example of irradiating the first resin-clad metal sheet with infrared rays using an infrared light source. [Figure 10] FIG. 10 is a schematic diagram for illustrating an example of irradiating the second resin-clad metal sheet with infrared rays using an infrared light source. [Figure 11] FIG. 11 is a schematic diagram for illustrating the application of pressure to a portion of the metal plate where the shape of the concave surface formed in the resin layer is not reflected. [Figure 12] FIG. 12 is a perspective view that schematically shows an example of a battery for an electric vehicle. [Figure 13] FIG. 13 is a schematic vertical cross-sectional view of the battery for an electric vehicle shown in FIG. [Figure 14] FIG. 14 is a perspective view that schematically shows another example of a battery for an electric vehicle. [Figure 15] FIG. 15 is a schematic vertical cross-sectional view of the battery for an electric vehicle shown in FIG. [Figure 16] FIG. 16 is a perspective view that schematically shows another example of a battery for an electric vehicle. [Figure 17] FIG. 17 is a schematic vertical cross-sectional view of the battery for an electric vehicle shown in FIG. [Figure 18] FIG. 18 is a perspective view that schematically shows another example of a battery for an electric vehicle. [Figure 19] FIG. 19 is a schematic vertical cross-sectional view of the battery for an electric vehicle shown in FIG. DETAILED DESCRIPTION OF THE INVENTION

[0022] As used herein, the following terms have the following meanings: The symbol "to" indicating a range of values ​​means that the values ​​before and after it are inclusive. Any combination of the lower and upper limits disclosed herein can be used to create any range of values.

[0023] Hereinafter, several embodiments of the present invention will be described with reference to the drawings. However, the following description relates to representative examples, and the embodiments of the present invention are not limited to the following description. Furthermore, the dimensional ratios in each drawing are for the convenience of explanation and may differ from the actual ones. In the following drawings, the same components are indicated by the same reference numerals, and descriptions of overlapping components may be omitted.

[0024] [Cooling unit] The cooling unit 50 shown in Fig. 5 is a cooling unit for an electric vehicle battery. In the cooling unit of Fig. 5, a first resin-laminated metal plate 10 and a second metal plate 3 are welded together via a first resin layer 2. The first resin-laminated metal plate 10 has a first metal plate 1 and a first resin layer 2 laminated on one side of the first metal plate 1.

[0025] 5, a concave surface 9 that serves as a refrigerant flow path 51 of the cooling unit 50 is formed in the first resin layer 2. Therefore, by joining the first resin-laminated metal plate 10 and the second metal plate 3, the refrigerant flow path 51 of the cooling unit 50 is formed.

[0026] Fig. 6 shows another example of a cooling unit. As shown in Fig. 6, a second resin laminated metal plate 11 may be used, which has a second metal plate 3 and a second resin layer 4 laminated on one side of the second metal plate 3. In the cooling unit of Fig. 6, a first resin laminated metal plate 10 and a second resin laminated metal plate 11 are welded and joined via the first resin layer 2 and the second resin layer 4.

[0027] 6, the first resin layer 2 also has a concave surface 9 that serves as the refrigerant flow path 51 of the cooling unit 50. Therefore, by joining the first resin laminated metal plate 10 and the second resin laminated metal plate 11, the refrigerant flow path 51 of the cooling unit 50 is formed. However, in another example (not shown), the concave surfaces that serve as the refrigerant flow path of the cooling unit may be formed in both the first resin layer 2 and the second resin layer 4, or the concave surfaces that serve as the refrigerant flow path of the cooling unit may be formed only in the second resin layer 4.

[0028] In the cooling unit of the present invention, no melting traces are observed in the resin forming the refrigerant flow path where it comes into contact with the metal plate in the portion where the concave shape is reflected. For example, as shown in Figure 7, the first metal plate 1 and the second metal plate 3 are welded and joined by molten resin 5. Resin 5 is formed when the first resin layer 2 and the second resin layer 4 melt and then solidify.

[0029] On the other hand, no melting marks are observed in the resin 6 forming the refrigerant flow path 51 in FIG. 7 at the portion where the shape of the concave surface 9 is reflected and where it comes into contact with the first metal plate 1. There are no melting marks, such as weld lines, on the surface or cross section of such resin 6. This is because the resin 6 is the portion of the first resin layer 2 that did not melt during joining and remained intact. If no melting marks are observed, there is no need to worry about the molten resin dripping as shown in FIG. 2 or the resin stringing as shown in FIG. 4.

[0030] 5 and 6, in the cooling unit according to the preferred embodiment, the solidified resin overflows from the ends of the joint surface of the resin layer, forming resin overflow portions 12 that conform to the shapes of both ends of the second metal plate 3. The formation of resin overflow portions 12 can improve the sealing performance of the refrigerant flow path of the cooling unit.

[0031] 6, in the cooling unit according to the preferred embodiment, the surface of the refrigerant flow path 51 is covered with the first resin layer 2 and the second resin layer 4 so that the refrigerant does not come into contact with the first metal plate 1 and the second metal plate 3. In this case, even if the refrigerant contains a corrosion-accelerating substance such as chloride ions, damage to the surface of the refrigerant flow path 51 is unlikely to occur. In addition, the risk of the refrigerant leaking outside the cooling unit is reduced.

[0032] There are no particular limitations on the shapes of the first metal plate 1 and the second metal plate 3. The first metal plate 1 and the second metal plate 3 may each be flat, have a curved surface, or have various complex shapes such as steps.

[0033] The materials for the first metal plate 1 and the second metal plate 3 are not particularly limited, but aluminum, aluminum alloys, copper, and copper alloys are preferred from the viewpoint of thermal conductivity, and aluminum and aluminum alloys are preferred from the viewpoint of weight reduction. Metals with higher thermal conductivity, such as silver, can also be used, but this increases the cost. The first metal plate 1 and the second metal plate 3 may be made of one type of material or two or more types of material.

[0034] The thickness of the first metal plate 1 and the second metal plate 3 is preferably 0.5 to 2.0 mm, more preferably 0.5 to 1.5 mm, and even more preferably 0.5 to 1.0 mm. The thinner the first metal plate 1 and the second metal plate 3, the lighter the cooling unit 50 can be. The thicker the first metal plate 1 and the second metal plate 3, the stronger the cooling unit 50 can be.

[0035] The thermal conductivity of the first metal plate 1 and the thermal conductivity of the second metal plate 3 are not particularly limited, but are each preferably 200 W / m K or more, more preferably 250 W / m K or more, and even more preferably 300 W / m K or more. The higher the thermal conductivity of the first metal plate 1 and the second metal plate 3, the better, as this improves cooling performance.

[0036] Although there are no particular limitations on the specific gravity of the first metal plate 1 and the second metal plate 3, each is preferably 4.0 or less, more preferably 3.5 or less, and even more preferably 3.0 or less. The lower the specific gravity of the first metal plate 1 and the second metal plate 3, the lighter the cooling unit 50 can be, which contributes to reducing the weight of the electric vehicle battery and the electric vehicle itself.

[0037] The resins for the first resin layer 2 and the second resin layer 4 are not particularly limited, but are preferably those that are not easily corroded by, dissolved in, or absorbed by the refrigerant. For example, when the refrigerant is a liquid whose main component is water, polyolefin resins such as polyethylene and polypropylene are preferred.

[0038] The first resin layer 2 and the second resin layer 4 each preferably contain a thermoplastic resin. The thermoplastic resin is not particularly limited, but examples thereof include polyolefin resins such as polyethylene and polypropylene, polyester resins, polystyrene resins, and polyamide resins, from the viewpoint of adhesiveness. From the viewpoint of adhesiveness, it is preferable that the bonding surfaces of the first resin layer 2 and the second resin layer 4 each be subjected to a physical or chemical roughening treatment.

[0039] The method for laminating the first metal sheet 1 and the first resin layer 2 and the method for laminating the second metal sheet 3 and the second resin layer 4 are not particularly limited, but an example of such a method is to interpose an adhesive between the metal sheet 1 (3) and the resin layer 2 (4) and then press them together. An example of a commercially available resin-laminated metal sheet 10, 11 is Hishimetal, manufactured by Mitsubishi Chemical Infratec Corporation.

[0040] The first resin layer 2 and the second resin layer 4 may each further contain a filler to improve thermal conductivity in addition to the resin. The filler is not particularly limited, but examples include metal powder, metal particles, metal oxide powder, metal oxide particles, and diamond particles. The particle size of the filler is not particularly limited as long as it is within a range that does not interfere with the effects of the present invention.

[0041] The thickness of the first resin layer 2 and the second resin layer 4 are not particularly limited, but are each preferably 0.05 to 0.2 mm, more preferably 0.05 to 0.15 mm, and even more preferably 0.05 to 0.1 mm. The thinner the first resin layer 2 and the second resin layer 4, the lighter the cooling unit 50. The thicker the first resin layer 2 and the second resin layer 4, the less likely the refrigerant will damage the surface of the refrigerant flow path 51.

[0042] The thermal conductivity of the first resin layer 2 and the thermal conductivity of the second resin layer 4 are not particularly limited, but are each preferably 0.1 W / m K or more, more preferably 0.3 W / m K or more, and even more preferably 0.5 W / m K or more. The higher the thermal conductivity of the first resin layer 2 and the thermal conductivity of the second resin layer 4, the better, as this improves cooling performance.

[0043] [Manufacturing method of cooling unit] 5 , a manufacturing method of a cooling unit for an electric vehicle battery according to one example includes joining a first resin-laminated metal plate 10 and a second metal plate 3 via a first resin layer 2 by infrared welding. Since a concave surface 9 that becomes a refrigerant flow path 51 of the cooling unit 50 is formed in the first resin layer 2, joining the first resin-laminated metal plate 10 and the second metal plate 3 forms the refrigerant flow path 51 of the cooling unit 50.

[0044] 6, a method for manufacturing a cooling unit for an electric vehicle battery according to another example includes joining a first resin laminated metal plate 10 and a second resin laminated metal plate 11 by infrared welding via a first resin layer 2 and a second resin layer 4. Because a concave surface 9 that becomes a refrigerant flow path 51 of a cooling unit 50 is formed in the first resin layer 2, joining the first resin laminated metal plate 10 and the second resin laminated metal plate 11 forms the refrigerant flow path 51 of the cooling unit 50. However, although not shown, in another example, the concave surfaces that become the refrigerant flow path of the cooling unit may be formed in both the first resin layer 2 and the second resin layer 4, or the concave surfaces that become the refrigerant flow path of the cooling unit may be formed only in the second resin layer 4.

[0045] As shown in FIG. 8, infrared welding can be performed by irradiating the first resin layer 2 of the first resin-laminated metal sheet 10 with infrared rays using an infrared light source 45. Infrared welding can melt only the resin layer in the first resin layer 2 in the portion that does not form the refrigerant flow path, i.e., the resin layer in the specific portion where the concave surface 9 is not formed. Therefore, as described with reference to FIG. 7, it is possible to manufacture a cooling unit having a refrigerant flow path formed from the resin 6 in which no melting traces are observed. Furthermore, by positioning the infrared light source 45 in a non-contact manner so that it can irradiate the resin layer at the desired position for welding with infrared rays, it is possible to melt only the specific resin layer. As a result, melting of the resin layer that forms the refrigerant flow path and stringiness of the resin can be prevented.

[0046] For example, as shown in Fig. 8, it is preferable to join the resin layer in the portion where the concave surface 9 is formed when the first resin-laminated metal sheet 10 is viewed from the side by infrared welding without irradiating it with infrared rays. It is also preferable to join the resin layer 2a in the portion adjacent to the concave surface 9 when the first resin-laminated metal sheet 10 is viewed from the side by infrared welding without irradiating it with infrared rays.

[0047] The distance p between the end of the infrared light source 45 on the concave surface 9 side and the end of the concave surface 9 is preferably 1 mm or more in side view, more preferably 2 mm or more, and even more preferably 3 mm or more. The distance d between the end of the infrared light source 45 on the resin layer side and the resin layer is preferably 2 mm or more in side view, more preferably 4 mm or more, and even more preferably 5 mm or more.

[0048] With infrared welding, even when a plurality of concave surfaces 9, 9 are formed in the resin layer, for example, as shown in Fig. 9, it is possible to limit the melting range of the resin layer by controlling the irradiation range of infrared rays from the infrared light source 45. Therefore, it is thought that the problem of limiting the size of the refrigerant flow path as described with reference to Fig. 3 is unlikely to occur. On the other hand, as shown in Fig. 10, when no concave surfaces are formed in the second resin layer 4, the infrared light source 45 may be arranged so that infrared rays are irradiated onto the entire surface.

[0049] In one example, it is preferable to apply pressure to the metal plate at a portion where the shape of the concave surface formed in the resin layer is not reflected and join them by infrared welding. For example, as shown in Fig. 11, it is possible to apply pressure to the metal plate 1a at a portion of the surface of the first metal plate 1 where the shape of the concave surface 9 formed in the first resin layer 2 is not reflected and join them by infrared welding.

[0050] [Batteries for electric vehicles, battery cases with cooling units] The cooling unit can be used as a cooling unit for an electric vehicle battery. The electric vehicle battery 100 shown in Figures 12 and 13 includes a battery module 71, a battery case 72 that houses the battery module 71, and a cooling unit 70 attached to the battery case 72.

[0051] The cooling unit 70 includes the above-described cooling unit 50. The cooling unit is not limited to the form illustrated in Figures 12 and 13. In the electric vehicle battery 100 shown in Figures 12 and 13, the cooling unit 70 is attached to the outside of the battery case 72.

[0052] 12 and 13, a piping joint that serves as a refrigerant inlet to refrigerant flow path 51 or a refrigerant outlet from refrigerant flow path 51 is joined to the surface opposite first metal plate 1 of the portion where the concave surface that serves as refrigerant flow path 51 is formed. The battery case 72 and battery module 71 can be cooled by supplying refrigerant into refrigerant flow path 51 from the piping joint on the inlet side (not shown) and discharging the refrigerant from the piping joint on the outlet side (not shown).

[0053] The battery module 71 is not particularly limited as long as it is a battery that requires cooling, but a secondary battery is preferable. Examples of secondary batteries include lead-acid batteries, nickel-cadmium batteries, metal lithium batteries, lithium-ion secondary batteries, lithium-ion polymer secondary batteries, and sodium-ion batteries. However, the battery module is not limited to these examples.

[0054] Lithium ion secondary batteries and lithium ion polymer secondary batteries are preferred, and lithium ion secondary batteries are more preferred, as they can be used at ambient temperatures, are lightweight, and have high voltage and energy density.

[0055] The material of the battery case 72 is not particularly limited as long as it is a material and shape that can accommodate the battery module 71, but a metal battery case or a synthetic resin battery case is preferred. Examples of the metal material for the battery case 72 include iron, aluminum, and aluminum alloys. However, the metal material is not limited to these examples. One type of metal material may be used alone, or two or more types may be used in combination.

[0056] Examples of synthetic resin materials for the battery case 72 include thermoplastic resin and thermosetting resin. From the viewpoint of the cooling efficiency of the cooling unit 70, a metal material is preferable, and a metal material with high thermal conductivity is more preferable. From the viewpoint of weight reduction, a synthetic resin material is preferable. The synthetic resin battery case 72 may be formed from a resin fiber composite material (fiber reinforced material) in which fibers such as glass fiber are mixed into a synthetic resin.

[0057] Examples of thermoplastic resins include polyolefin resins such as polyethylene and polypropylene, polyester resins, polystyrene resins, polyamide resins, acrylonitrile-butadiene-styrene (ABS) resins, polyvinyl acetal resins, ethylene vinyl acetate copolymer (EVA) resins, polyvinyl alcohol resins, polycarbonate resins, polyphenylene ether resins, acrylic resins, polyvinyl chloride resins (PVC), novolac resins, polyurethane resins, and polyisobutylene resins. However, the thermoplastic resins are not limited to these examples. One type of thermoplastic resin may be used alone, or two or more types may be used in combination.

[0058] Examples of thermosetting resins include epoxy resins, vinyl ester resins, urethane resins, phenolic resins, urea resins, melamine resins, unsaturated polyester resins, and polyimide resins. From the viewpoint of recyclability, the synthetic resin preferably contains a thermoplastic resin, more preferably contains a polyolefin resin, and even more preferably contains a polypropylene resin. However, the thermosetting resin is not limited to these examples. One type of thermosetting resin may be used alone, or two or more types may be used in combination.

[0059] 14 and 15, in another example, the joint surface between the battery case 72 and the cooling unit 70 may be curved. In this way, the joint surface between the battery case and the cooling unit may be flat or curved.

[0060] As illustrated in Figures 16 and 17, in another example, the joint surface between the battery case 72 and the cooling unit 70 may have various complex shapes, such as a step 74 (Figure 17) at the joint surface between the battery case 72 and the cooling unit 70.

[0061] 18 and 19, in another example, the cooling unit 70 may be attached to the inside of the battery case 72. In this case, it is preferable that the second metal plate 3 of the second resin-laminated metal plate 11 is in direct contact with the battery module 71. Direct contact between the battery module 71 and the second metal plate 3 of the cooling unit 70 can provide better cooling performance.

[0062] Although not shown in Figures 16, 17, 18 and 19, a piping joint that serves as a refrigerant inlet to refrigerant flow path 51 or a refrigerant outlet from refrigerant flow path 51 is joined to the surface opposite to first metal plate 1 in the portion where the concave surface that serves as refrigerant flow path 51 is formed.

[0063] 12, 13, 14, 15, 16, 17, 18, and 19 each disclose a battery case with a cooling unit, which includes a battery case 72 and a cooling unit 70 attached to the battery case 72. The cooling unit 70 encompasses the cooling unit 50 described above.

[0064] Although not shown in the figures, the second resin-laminated metal plate can be omitted in an electric vehicle battery or a battery case with a cooling unit. If the first resin-laminated metal plate is directly joined to the battery case, the second resin-laminated metal plate can be omitted. To manufacture an electric vehicle battery or a battery case with a cooling unit that does not require a second resin-laminated metal plate, the first resin-laminated metal plate can be bonded to the inside or outside of the battery case via a first resin layer that has a concave surface that serves as a refrigerant flow path for the cooling unit. As shown in Figures 8 and 9, by melting only the first resin layer in the portion that does not form the refrigerant flow path, that is, the first resin layer in the specific portion that does not have a concave surface, it is possible to manufacture a cooling unit that has a refrigerant flow path formed by the resin and the surface of the battery case, with no visible melting marks.

[0065] Although several specific embodiments have been described above, each embodiment is presented as an example and does not limit the scope of the present invention. Each embodiment described in this specification can be modified in various ways within the scope of the effects of the invention and can be combined with features described in other embodiments within the scope of feasibility. [Industrial Applicability]

[0066] According to the present invention, there is provided a cooling unit and a manufacturing method thereof that has a refrigerant flow path formed primarily from resin, but can prevent blockage of the refrigerant flow path and a decrease in refrigerant efficiency caused by molten resin. [Explanation of symbols]

[0067] 1. First metal plate 2. First resin layer 3 Second metal plate 4 Second resin layer 5 Molten resin 6. Resin with no visible melting marks 8. Adhesive 9 concave 10 First resin-laminated metal plate 11 Second resin-laminated metal plate 45 Infrared light source 50 Cooling Unit 70 Cooling Unit 100 Electric vehicle batteries

Claims

1. A cooling unit for an electric vehicle battery, a first resin-laminated metal plate having a first metal plate and a first resin layer laminated on one surface of the first metal plate, and a second metal plate are welded and joined via the first resin layer; a concave surface that serves as a refrigerant flow path of the cooling unit is formed in the first resin layer; A cooling unit, wherein no melting traces are observed in the resin forming the refrigerant flow path at a portion where the shape of the concave surface is reflected and the resin is in contact with the first metal plate.

2. A cooling unit for an electric vehicle battery, a first resin-laminated metal sheet having a first metal plate and a first resin layer laminated on one surface of the first metal plate, and a second resin-laminated metal sheet having a second metal plate and a second resin layer laminated on one surface of the second metal plate, the first resin layer and the second resin layer being welded and joined together; a concave surface that serves as a refrigerant flow path of the cooling unit is formed in one or both of the first resin layer and the second resin layer; A cooling unit, wherein no melting traces are observed in the resin forming the refrigerant flow path at a portion where the resin comes into contact with the metal plate in a portion where the shape of the concave surface is reflected.

3. The cooling unit according to claim 2 , wherein the first resin layer contains a thermoplastic resin or the second resin layer contains a thermoplastic resin.

4. 3. The cooling unit according to claim 2, wherein the first resin layer has a thickness of 0.05 to 0.2 mm, or the second resin layer has a thickness of 0.05 to 0.2 mm.

5. The cooling unit according to claim 2 , wherein the thermal conductivity of the first resin layer is 0.1 W / m·K or more, or the thermal conductivity of the second resin layer is 0.1 W / m·K or more.

6. The cooling unit according to claim 2 , wherein a surface of the refrigerant flow path is covered with the first resin layer and the second resin layer so that the refrigerant does not come into contact with the first metal plate and the second metal plate.

7. The cooling unit according to claim 2 , wherein solidified resin overflows from an end portion where the first resin-clad metal plate and the second resin-clad metal plate are joined.

8. 2. The cooling unit according to claim 1, wherein the first metal plate has a thickness of 0.5 to 2.0 mm, or the second metal plate has a thickness of 0.5 to 2.0 mm.

9. The cooling unit according to claim 1 , wherein the thermal conductivity of the first metal plate is 200 W / m·K or more, or the thermal conductivity of the second metal plate is 200 W / m·K or more.

10. The cooling unit according to claim 1 , wherein the specific gravity of the first metal plate is 4.0 or less, or the specific gravity of the second metal plate is 4.0 or less.

11. The cooling unit according to claim 1 , wherein solidified resin overflows from an end portion where the first resin-laminated metal plate and the second metal plate are joined.

12. A method for manufacturing a cooling unit for an electric vehicle battery, The method includes joining a first resin-laminated metal plate having a first metal plate and a first resin layer laminated on one surface of the first metal plate to a second metal plate by infrared welding via the first resin layer, The manufacturing method, wherein the first resin layer has a concave surface that serves as a refrigerant flow path for the cooling unit.

13. A method for manufacturing a cooling unit for an electric vehicle battery, a first resin-laminated metal plate having a first metal plate and a first resin layer laminated on one surface of the first metal plate, and a second resin-laminated metal plate having a second metal plate and a second resin layer laminated on one surface of the second metal plate, joined together by infrared welding via the first resin layer and the second resin layer; A manufacturing method, wherein a concave surface that serves as a refrigerant flow path of the cooling unit is formed in one or both of the first resin layer and the second resin layer.

14. The manufacturing method according to claim 12 or 13, wherein the resin layer in the portion where the concave surface is formed when the first resin-laminated metal plate is viewed from the side is joined by infrared welding without irradiating it with infrared rays.

15. The manufacturing method according to claim 12 or 13, wherein the resin layer in a portion adjacent to the concave surface when the first resin-laminated metal plate is viewed from the side is also joined by infrared welding without irradiating it with infrared rays.

16. The manufacturing method according to claim 12 or 13, wherein the metal plate in the portion where the shape of the concave surface is not reflected is pressed and joined by infrared welding.

17. The manufacturing method according to claim 13 , wherein the first resin layer contains a thermoplastic resin or the second resin layer contains a thermoplastic resin.

18. The manufacturing method according to claim 13, wherein the first resin layer has a thickness of 0.05 to 0.2 mm, or the second resin layer has a thickness of 0.05 to 0.2 mm.

19. The manufacturing method according to claim 13 , wherein the thermal conductivity of the first resin layer is 0.1 W / m·K or more, or the thermal conductivity of the second resin layer is 0.1 W / m·K or more.

20. The manufacturing method according to claim 12, wherein the thickness of the first metal plate is 0.5 to 2.0 mm, or the thickness of the second metal plate is 0.5 to 2.0 mm.

21. The manufacturing method according to claim 12, wherein the thermal conductivity of the first metal plate is 200 W / m·K or more, or the thermal conductivity of the second metal plate is 200 W / m·K or more.

22. The manufacturing method according to claim 12 , wherein the specific gravity of the first metal plate is 4.0 or less, or the specific gravity of the second metal plate is 4.0 or less.

23. Battery case and a cooling unit attached to the battery case; Equipped with A battery case with a cooling unit for an electric vehicle battery, wherein the cooling unit is the cooling unit according to any one of claims 1 to 11.

24. A battery module; a battery case that houses the battery module; a cooling unit attached to the battery case; Equipped with A battery for an electric vehicle, wherein the cooling unit is the cooling unit according to any one of claims 1 to 11.

25. 25. The electric vehicle battery of claim 24, wherein the cooling unit is mounted to the outside of the battery case.

26. 25. The electric vehicle battery of claim 24, wherein the cooling unit is mounted inside the battery case.

27. Battery case and a cooling unit attached to the battery case; Equipped with the cooling unit includes a first resin-laminated metal plate having a first metal plate and a first resin layer laminated on one surface of the first metal plate; the first resin layer has a concave surface that serves as a refrigerant flow path for the cooling unit; the battery case and the first resin-laminated metal plate are welded and joined via the first resin layer, A battery case with a cooling unit for an electric vehicle battery, wherein no melting traces are observed in the resin forming the refrigerant flow path at the portion where the shape of the concave surface is reflected and in contact with the first metal plate.

28. 28. The battery case with a cooling unit for an electric vehicle battery according to claim 27, wherein solidified resin overflows from an end where the battery case and the first resin-laminated metal plate are joined.

29. 28. The battery case with a cooling unit for an electric vehicle battery according to claim 27, wherein the first resin layer contains a thermoplastic resin.

30. The battery case with a cooling unit for an electric vehicle battery according to claim 27, wherein the first resin layer has a thickness of 0.05 to 0.2 mm.

31. 28. The battery case with a cooling unit for an electric vehicle battery according to claim 27, wherein the thermal conductivity of the first resin layer is 0.1 W / m·K or more.

32. The battery case with a cooling unit for an electric vehicle battery according to claim 27, wherein the thickness of the first metal plate is 0.5 to 2.0 mm.

33. 28. The battery case with a cooling unit for an electric vehicle battery according to claim 27, wherein the thermal conductivity of the first metal plate is 200 W / m·K or more.

34. 28. The battery case with a cooling unit for an electric vehicle battery according to claim 27, wherein the specific gravity of the first metal plate is 4.0 or less.

35. A battery module; a battery case that houses the battery module; a cooling unit attached to the battery case; Equipped with the cooling unit includes a first resin-laminated metal plate having a first metal plate and a first resin layer laminated on one surface of the first metal plate; a concave surface that serves as a refrigerant flow path of the cooling unit is formed in the first resin layer; the battery case and the first resin-laminated metal plate are welded and joined via the first resin layer, A battery for an electric vehicle, wherein no melting traces are observed in the resin forming the refrigerant flow path at a portion where the shape of the concave surface is reflected and the resin is in contact with the first metal plate.

36. 36. The electric vehicle battery of claim 35, wherein the cooling unit is mounted to the outside of the battery case.

37. 36. The electric vehicle battery of claim 35, wherein the cooling unit is mounted inside the battery case.

38. 36. The battery for an electric vehicle according to claim 35, wherein solidified resin overflows from an end portion where the battery case and the first resin-laminated metal plate are joined.

39. 36. The electric vehicle battery of claim 35, wherein the first resin layer comprises a thermoplastic resin.

40. The battery for electric vehicles according to claim 35, wherein the first resin layer has a thickness of 0.05 to 0.2 mm.

41. 36. The battery for an electric vehicle according to claim 35, wherein the thermal conductivity of the first resin layer is 0.1 W / m·K or more.

42. 36. The battery for an electric vehicle according to claim 35, wherein the first metal plate has a thickness of 0.5 to 2.0 mm.

43. 36. The battery for an electric vehicle according to claim 35, wherein the thermal conductivity of the first metal plate is 200 W / m·K or greater.

44. 36. The electric vehicle battery of claim 35, wherein the first metal plate has a specific gravity of 4.0 or less.

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