Cooling heat exchanger

Abstract

Provided is a cooling heat exchanger which has a novel structure, and is capable of tolerating a difference in deformation amount due to thermal expansion between a metallic cooling surface constituent member superposed on a cooling object and a synthetic resinous flow path member superposed on and fixed to the cooling surface constituent member.　A cooling heat exchanger 10 has a lamination structure in which a metallic cooling surface constituent member 12 superposed on a cooling object B and a synthetic resinous flow path member 14 are superposed on each other, and a cooling flow path 58 through which a cooling heat medium flows is formed between the superposed surfaces of the cooling surface constituent member 12 and the flow path member 14. The cooling surface constituent member 12 and the flow path member 14 are bonded to each other by means of an adhesive layer 54 having elasticity in the outer peripheral regions. The cooling surface constituent member 12 and the flow path member 14 are fixed to each other by direct bonding without an adhesive in a direct bonding portion 44 provided in a central region of the flow path member 14.

Description

cooling heat exchanger

[0001] The present invention relates to a cooling heat exchanger used to cool an object to be cooled, such as a battery pack in an electrically powered vehicle such as an electric automobile.

[0002] For example, in electrically powered vehicles such as electric vehicles and hybrid vehicles, the heat generated by the battery packs and electronic devices to be cooled is increasing due to miniaturization and high performance, making cooling performance increasingly important. Conventionally, cooling heat exchangers have been used that have a structure in which cooling channels are formed between overlapping metal plates. In this cooling heat exchanger, one plate is overlapped with the cooling target, such as a battery pack, and the cooling target is cooled by the cooling medium flowing through the cooling channel.

[0003] In addition, due to the strong demand for lightweight vehicles in electric vehicles, weight reduction of cooling heat exchangers is also being considered. For example, International Publication No. 2020 / 196878 (Patent Document 1) proposes that one plate, which is superimposed on the object to be cooled and for which thermal conductivity is important, is made of metal, and the other plate, which does not require thermal conductivity, is made of a resin member made of a synthetic resin with a specific gravity lower than that of metal. In Patent Document 1, the resin member is a box body with an opening on the top surface, and a flow path forming rib is provided integrally with the box body inside the box body.

[0004] International Publication No. 2020 / 196878

[0005] However, the inventors of the present invention have found that, in the structure of Patent Document 1, when the metal plate and the resin member are overlapped and fixed to each other by adhesive or other means, deflection occurs in the plate thickness direction due to the difference in linear expansion coefficient. Therefore, in extremely high or low temperature environments, the difference in deformation due to thermal expansion between the metal plate and the resin member may cause the cooling heat exchanger to deflect, leading to separation between the metal plate and the resin member and a decrease in cooling performance. In particular, cooling heat exchangers used in electric vehicles are large in the length and width directions perpendicular to the overlapping direction of the metal plate and the resin member, and therefore the difference in deformation due to the difference in linear expansion coefficient between the metal plate and the resin member is likely to become a problem.

[0006] The problem to be solved by the present invention is to provide a cooling heat exchanger having a novel structure that can tolerate the difference in deformation amount due to the difference in the linear expansion coefficient between a metal cooling surface component that is overlaid on the object to be cooled and a synthetic resin flow path component that is overlaid on and fixed to the cooling surface component.

[0007] The following describes preferred embodiments for understanding the present invention, but the embodiments described below are merely examples and may be appropriately combined with one another. Multiple components described in each embodiment may be recognized and employed independently to the greatest extent possible, and may also be appropriately combined with any of the components described in other embodiments. Accordingly, the present invention is not limited to the embodiments described below, and various other embodiments may be realized.

[0008] The first aspect is a cooling heat exchanger having a laminated structure in which a metal cooling surface component and a synthetic resin flow path component are superimposed on the object to be cooled, and a cooling flow path through which a cooling heat medium flows is formed between the superimposed surfaces of the cooling surface component and the flow path component, and the cooling surface component and the flow path component are bonded to each other in their outer peripheral regions by an elastic adhesive layer, and are fixed to each other by direct bonding without adhesive at a direct bonding portion provided in the central region of the flow path component.

[0009] In a cooling heat exchanger constructed according to this aspect, the metal cooling surface component and the synthetic resin flow path component are bonded to each other by an elastic adhesive layer, so that the difference in deformation due to the difference in linear expansion coefficient between the flow path component and the cooling surface component in response to temperature changes, for example, is tolerated by the elastic deformation of the adhesive layer, thereby reducing or preventing warping of the cooling heat exchanger due to the difference in linear expansion coefficient between the flow path component and the cooling surface component.

[0010] The flow path member and the cooling surface member are bonded together with an adhesive layer in the outer peripheral region of the flow path member, and are fixed to each other by direct bonding without an adhesive layer at a direct bonding portion provided in the central region of the flow path member. The provision of such a direct bonding portion prevents misalignment or separation between the flow path member and the cooling surface member, and also prevents damage (peeling) to the adhesive layer due to differences in the linear expansion coefficients of the flow path member and the cooling surface member.

[0011] In particular, because the direct bond that positions the flow path member and the cooling surface component relative to each other is located in the central region of the flow path member, the distance from the direct bond to the outer circumferential edge of the flow path member is relatively small over the entire circumference. Since the difference in the amount of deformation due to the difference in the linear expansion coefficients of the flow path member and the cooling surface component increases as the distance from the direct bond increases, the difference in the amount of deformation due to the difference in the linear expansion coefficients of the flow path member and the cooling surface component is suppressed even at the outer circumferential edge of the flow path member that is farthest from the direct bond.

[0012] In the cooling heat exchanger of this embodiment, differences in the linear expansion coefficients of the flow path member and the cooling surface constituent member are allowed, so the linear expansion coefficient is less likely to be an issue when selecting the synthetic resin material for the flow path member and the metal material for the cooling surface constituent member, and the materials for forming the flow path member and the cooling surface constituent member can be selected with great freedom.

[0013] In a second aspect, in the cooling heat exchanger described in the first aspect, an adhesive surface is provided at the adhesive portion of the flow path member with the cooling surface component member, where an adhesive is applied to form the adhesive layer, and a position determining portion is provided around the adhesive surface that protrudes toward the cooling surface component member from the adhesive surface and determines the thickness of the adhesive layer.

[0014] In a cooling heat exchanger constructed according to this aspect, the relative positions of the flow path member and the cooling surface member in the overlapping direction are determined by the abutment of the cooling surface member with the position determining portion, so the thickness of the adhesive layer formed between the overlapping surfaces of the flow path member and the cooling surface member is set with precision. As a result, the allowable amount of deformation due to the difference in linear expansion coefficient between the flow path member and the cooling surface member caused by the elasticity of the adhesive layer is set with precision, and warping of the cooling heat exchanger due to temperature changes, damage to or peeling of the adhesive layer, etc. are more reliably prevented.

[0015] In particular, since the position determining portion is provided around the adhesive surface where the adhesive is applied, the thickness of the adhesive layer can be set more accurately than if it were provided at a position far away from the adhesive surface.

[0016] In a third aspect, in the cooling heat exchanger described in the second aspect, an adhesive escape portion that allows the adhesive constituting the adhesive layer to overflow is provided between the adhesive surface and the position determining portion, between the overlapping surfaces of the flow path member and the cooling surface constituent member.

[0017] In a cooling heat exchanger constructed in accordance with this aspect, for example, when the thickness of the adhesive on the adhesive surface is made thicker than the distance between the opposing surfaces of the adhesive surface and the cooling surface component, which is determined by the position determining portion, and an adhesive layer of a predetermined thickness is formed between the opposing surfaces of the adhesive surface and the cooling surface component, an adhesive escape portion is provided that allows excess adhesive to overflow from the adhesive surface, thereby preventing problems such as the overflowing adhesive leaking into the cooling flow path.

[0018] The adhesive escape portion is preferably recessed and has a bottom surface that is farther from the cooling surface component than the adhesive surface, which makes it easier to distinguish between the adhesive surface and the adhesive escape portion, makes it easier to ensure the volume of the adhesive escape portion, and makes it less likely that adhesive that has spilled out from the adhesive surface will overflow from the adhesive escape portion.

[0019] In a fourth aspect, in the cooling heat exchanger described in the second or third aspect, the adhesive escape portion is provided continuously around the entire circumference of the adhesive surface, and the position determination portion is provided continuously around the entire circumference of the adhesive escape portion.

[0020] In a cooling heat exchanger constructed according to this aspect, the adhesive escape portion is provided so as to surround the entire periphery of the adhesive surface, allowing the adhesive to ooze outward from the adhesive surface in any direction. Also, the position determining portion is provided so as to surround the entire periphery of the adhesive escape portion, preventing the adhesive from leaking outward from the adhesive escape portion.

[0021] Furthermore, since the position determining portion is provided around the entire circumference of the adhesive surface, the thickness of the adhesive layer formed between the opposing surfaces of the adhesive surface and the cooling surface component can be set more accurately.

[0022] In a fifth aspect, in the cooling heat exchanger described in any one of the first to fourth aspects, a plurality of the flow path members are superimposed on one of the cooling surface constituent members, and the direct joint portion is provided in the central region of each of the flow path members.

[0023] In a cooling heat exchanger constructed according to this aspect, each flow path member can be made compact, and the difference in deformation between each flow path member and the cooling surface component due to differences in linear expansion coefficients in response to temperature changes can be reduced. In particular, since the direct bonded portions are provided in the central regions of each flow path member, which can be made compact, the distance from the direct bonded portions to the outer peripheral edge of each flow path member can be shortened. This more effectively prevents warping of the cooling heat exchanger and damage to the adhesive layer.

[0024] By attaching a plurality of flow path members to one cooling surface component, it is possible to reduce the size of each flow path member while integrally obtaining a sufficiently large cooling heat exchanger.

[0025] A sixth aspect is a cooling heat exchanger according to any one of the first to fifth aspects, in which one flow path member is superimposed on one cooling surface component member.

[0026] The cooling heat exchanger constructed according to this aspect can be constructed with a small number of parts, using only one flow path member and one cooling surface member. Moreover, even if the flow path member and the cooling surface member each have a large area, problems such as warping of the cooling heat exchanger or separation between the flow path member and the cooling surface member due to differences in the linear expansion coefficients of the flow path member and the cooling surface member can be reduced.

[0027] A seventh aspect is a cooling heat exchanger according to any one of the first to sixth aspects, wherein the direct joint portion is provided at only one location in the center of the flow path member.

[0028] The cooling heat exchanger constructed according to this embodiment has a simplified structure compared to a case in which the central region is directly bonded at multiple locations. Furthermore, if multiple direct bond portions are provided, there is a risk that the difference in the amount of deformation between the flow path member and the cooling surface component due to the difference in linear expansion coefficients between the multiple direct bond portions may not be tolerated. However, if the direct bond portion is provided at only one central location, the difference in the amount of deformation over the entire outer periphery of the direct bond portion can be tolerated by the adhesive layer.

[0029] According to the present invention, it is possible to tolerate the difference in the amount of deformation caused by the difference in the linear expansion coefficient between the metal cooling surface component that is overlaid on the object to be cooled and the synthetic resin flow path component that is overlaid on and fixed to the cooling surface component.

[0030] 1 is a plan view of the cooling heat exchanger shown in FIG. 1; sectional view taken along III-III in FIG. 2; sectional view taken along IV-IV in FIG. 2; sectional view of the cooling heat exchanger shown in FIG. 1; sectional view of the cooling heat exchanger shown in FIG. 1; sectional view of the cooling heat exchanger shown in FIG. 6;

[0031] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0032] 1 to 4 show a cooling heat exchanger 10 according to a first embodiment of the present invention. As also shown in Fig. 5, the cooling heat exchanger 10 has a laminated structure in which a metal plate 12 serving as a cooling surface component and a resin plate 14 serving as a flow path component are overlapped and fixed to each other. In the following description, in principle, the up-down direction refers to the left-right direction in Fig. 3, which is the overlapping direction of the metal plate 12 and the resin plate 14, the front-rear direction refers to the up-down direction in Fig. 2, and the left-right direction refers to the left-right direction in Fig. 2.

[0033] The metal plate 12 has a rectangular plate shape that is approximately square when viewed from above. The metal plate 12 is preferably made of a metal material with high thermal conductivity, such as aluminum, copper, stainless steel, or an alloy thereof.

[0034] A plurality of lightening holes 16 are formed in the metal plate 12. Each lightening hole 16 has a generally oval cross-sectional shape that is longer in the left-right direction than in the front-rear direction, and in this embodiment, six lightening holes 16 are arranged in three rows in the front-rear direction and two rows in the left-right direction.

[0035] An insertion hole 18 is formed in the left-right center of the metal plate 12, penetrating the metal plate 12. A plurality of the insertion holes 18 are formed spaced apart from one another in the front-rear direction. The insertion hole 18 is located in the front-rear center between adjacent lightening holes 16, 16 in the front-rear direction.

[0036] A plurality of through-holes (not shown) are formed in both the left and right ends of the metal plate 12, and a port member 20 is attached to each through-hole. The port member 20 has a generally cylindrical shape that extends in the vertical direction as a whole, and is integrally formed at the lower end with a flange-like portion 22 that protrudes outward toward the outer periphery.

[0037] A retaining projection 24 that protrudes outward is formed in the middle of the upper and lower portions of the port member 20. The retaining projection 24 has a smaller projection dimension toward the outer periphery than the flange-shaped portion 22 and is generally semicircular in longitudinal cross section. The retaining projection 24 is insertable into a tube or the like of an external flow path (described below), and serves to prevent the tube or the like of an external flow path (not shown) that is connected to the port member 20 in an externally inserted state from coming out.

[0038] The port member 20 is overlapped on the upper surface of the metal plate 12 at the periphery of the opening of the through hole in the metal plate 12 and is fixed to the metal plate 12 by means of adhesive, welding, or the like. In this embodiment, a flange-shaped portion 22 is provided at the lower end of the port member 20, which increases the overlapping area with the upper surface of the metal plate 12 and makes it easier to ensure the bonding strength between the metal plate 12 and the port member 20. The inner hole of the port member 20 is positioned relative to the through hole in the metal plate 12 and is in communication with the space below the metal plate 12.

[0039] The resin plate 14 has a rectangular plate shape when viewed from above and below, and is longer in the left-right direction than in the front-rear direction. As shown in Fig. 2, the width of the resin plate 14 in the left-right direction is approximately the same as or slightly smaller than that of the metal plate 12, and the length of the resin plate 14 in the front-rear direction is smaller than that of the metal plate 12. The front-rear length of the resin plate 14 is equal to or less than one-fourth the front-rear length of the metal plate 12, and is approximately the same as the distance between adjacent lightening holes 16, 16 in the front-rear direction of the metal plate 12.

[0040] The resin plate 14 is made of a hard synthetic resin, preferably a thermoplastic synthetic resin material. Suitable materials for the resin plate 14 include polyamide, polyester, fluororesin, polyolefin, etc. The resin plate 14 can also be made of a fiber-reinforced synthetic resin reinforced with glass fiber, carbon fiber, etc.

[0041] As shown in FIG. 5 , the resin plate 14 has a recess 26 that opens to the upper surface. In other words, the resin plate 14 has a substantially rectangular, annular outer circumferential bonding portion 28 whose outer peripheral end protrudes upward. The outer circumferential bonding portion 28 extends circumferentially with a predetermined width. As shown in FIG. 3 , the outer circumferential bonding portion 28 includes a planar bonding surface 30 that extends substantially perpendicular to the up-down direction in the widthwise middle portion, a relief groove 32 that serves as an adhesive relief portion that opens upward on the inner circumferential side of the bonding surface 30, and positioning portions 34 a, 34 b provided on the outer circumferential side of the bonding surface 30 and the inner circumferential side of the relief groove 32. The bonding surface 30, the relief groove 32, and the positioning portions 34 a, 34 b of the outer circumferential bonding portion 28 are all continuous annularly around the entire circumference.

[0042] The resin plate 14 is provided with a plurality of inner peripheral adhesive portions 36 that protrude upward from the bottom surface of the recess 26. As shown in Fig. 3, the inner peripheral adhesive portions 36 are ridges that extend linearly in the left-right direction. When viewed from above, the inner peripheral adhesive portions 36 have a generally rectangular shape with long sides that extend linearly in the left-right direction at the middle portion in the left-right direction, and both left and right ends are generally semicircular in top view, resulting in an overall generally oval shape that is long in the left-right direction.

[0043] The inner peripheral adhesive portion 36 comprises an adhesive surface 38 extending approximately perpendicular to the vertical direction, an annular escape groove 40 as an adhesive escape portion extending to surround the entire periphery of the adhesive surface 38, and an annular position determination portion 42 extending to surround the entire periphery of the escape groove 40.

[0044] The bottom surface of the relief groove 40 is located below the adhesive surface 38. Therefore, the portion of the inner circumferential adhesive portion 36 that forms the adhesive surface 38 protrudes upward relative to the portion where the relief groove 40 is formed. Furthermore, the upper surface of the position determining portion 42 is located above the bottom surface of the relief groove 40, and is located above the adhesive surface 38. The difference d in the vertical position between the adhesive surface 38 and the upper surface of the position determining portion 42 is set to the design thickness dimension of the adhesive layer 54, which will be described later.

[0045] In the resin plate 14, four inner periphery adhesive portions 36 are arranged side by side in the front-to-rear direction while being spaced apart from one another. The inner periphery adhesive portions 36a located at the outer ends in the front-to-rear direction are longer in the left-to-right direction than the inner periphery adhesive portions 36b located in the middle in the front-to-rear direction. The inner periphery adhesive portions 36b located in the middle in the front-to-rear direction are arranged in two rows, front to back and two rows, left to right. In the recess 26, grooves extending in the left-to-right direction are formed between the inner periphery adhesive portion 36a and the outer periphery adhesive portion 28, between the inner periphery adhesive portion 36a and the inner periphery adhesive portion 36b, and between the inner periphery adhesive portion 36b and the inner periphery adhesive portion 36b.

[0046] A central joint 44, which constitutes a direct joint, is provided between the inner peripheral adhesive portions 36b, 36b located on the left side and the inner peripheral adhesive portions 36b, 36b located on the right side. The central joint 44 is provided integrally with the resin plate 14 and protrudes upward from the bottom surface of the recess 26. The central joint 44 is cylindrical, and its center hole constitutes an insertion hole 46 that passes through the resin plate 14.

[0047] Similar to the inner peripheral bonding portion 36, the outer peripheral side of the insertion hole 46 in the central bonding portion 44 is provided with an annular bonding surface 48, a relief groove 50a as an adhesive relief portion extending inner circumferentially along the bonding surface 48, a relief groove 50b as an adhesive relief portion extending outer circumferentially along the bonding surface 48, a position determining portion 52a extending inner circumferentially along the relief groove 50a, and a position determining portion 52b extending outer circumferentially along the relief groove 50b. In the central bonding portion 44, the relief grooves 50a, 50b are provided so as to surround the entire inner and outer peripheries of the bonding surface 48. In addition, in the central bonding portion 44, the position determining portion 52a is provided annularly on the inner peripheral side along the entire length of the relief groove 50a, and the position determining portion 52b is provided annularly on the outer peripheral side along the entire length of the relief groove 50b. The adhesive surface 48, the relief grooves 50a, 50b, and the position determining portions 52a, 52b are all annular. The relief groove 50 of the central adhesive portion 44 is narrower than the relief groove 40 of the inner adhesive portion 36. The position determining portion 52 of the central adhesive portion 44 is narrower than the position determining portion 42 of the inner adhesive portion 36. However, the relief groove 50 of the central adhesive portion 44 and the relief groove 40 of the inner adhesive portion 36 may have the same width, or the relief groove 50 may be wider than the relief groove 40. Similarly, the position determining portion 52 of the central adhesive portion 44 and the position determining portion 42 of the inner adhesive portion 36 may have the same width, or the position determining portion 52 may be wider than the position determining portion 42.

[0048] The bottom surfaces of the relief grooves 50a, 50b are located below the adhesive surface 48. Therefore, the portion of the central joint 44 that forms the adhesive surface 48 protrudes upward relative to the portions where the relief grooves 50a, 50b are formed. Furthermore, the upper surfaces of the position defining portions 52a, 52b are located above the bottom surfaces of the relief grooves 50a, 50b, and above the adhesive surface 48. The difference d in the vertical position between the adhesive surface 48 and the upper surface of the position defining portion 52 is set to the thickness dimension of the adhesive layer 54, which will be described later.

[0049] The metal plate 12 is placed on top of the resin plate 14. The metal plate 12 is placed on top of the resin plate 14 while abutting against the position determining portions 34, 42, and 52 of the resin plate 14. As a result, the relative positions of the resin plate 14 and the metal plate 12 in the overlapping direction are determined by the position determining portions 34, 42, and 52.

[0050] With the resin plate 14 and the metal plate 12 positioned relative to each other by the positioning portions 34, 42, 52, the adhesive surfaces 30, 38, 48 face and are spaced downward from the metal plate 12. The bottom surfaces of the relief grooves 32, 40, 50 are also spaced downward from the metal plate 12, with the distance of this space being greater than the distance between the metal plate 12 and the adhesive surfaces 30, 38, 48.

[0051] An adhesive layer 54 is formed between the opposing surfaces of the bonding surfaces 30, 38, and 48 and the metal plate 12, respectively, and the outer periphery of the resin plate 14 is bonded to the metal plate 12 by the adhesive layer 54. The adhesive layer 54 is formed by applying an adhesive to the bonding surfaces 30, 38, and 48, and solidifying the adhesive layer between the bonding surfaces 30, 38, and 48 and the underside of the metal plate 12 as the metal plate 12 is placed on the resin plate 14. The adhesive layer 54 is elastic and allows relative displacement between the bonding surfaces 30, 38, and 48 and the metal plate 12 through elastic deformation, while maintaining the bonding surfaces 30, 38, and 48 and the metal plate 12 in a mutually connected state. The Young's modulus of the adhesive layer 54 is preferably 500 MPa or less, and more preferably 100 MPa or less.

[0052] The adhesive that forms the elastic adhesive layer 54 may be, for example, a urethane-based adhesive or a mixture of epoxy and silicone adhesives, and a specific example is "EP001K" manufactured by Cemedine Co., Ltd.

[0053] The thickness of the adhesive layer 54 is determined by the difference in vertical position d between the adhesive surfaces 30, 38, 48 and the upper surfaces of the positioning portions 34, 42, 52. In other words, when the metal plate 12 is placed in contact with the upper surfaces of the positioning portions 34, 42, 52, an adhesive layer 54 having a thickness d is formed between the adhesive surface 30 and the metal plate 12. In this way, the thickness of the adhesive layer 54 is set stably and accurately based on the relative vertical positional relationship between the adhesive surfaces 30, 38, 48 and the upper surfaces of the positioning portions 34, 42, 52. The thickness d of the adhesive layer 54 is preferably set within a range of 0.02 mm to 5 mm, and more preferably within a range of 0.2 mm to 1 mm.

[0054] To ensure that the thickness of the adhesive layer 54 is consistently d, the thickness of the adhesive applied to the bonding surfaces 30, 38, and 48 must be greater than d, and then the adhesive on the bonding surfaces 30, 38, and 48 must be thinned to d by overlapping the metal plates 12. Therefore, when the adhesive becomes thinner than when applied to the bonding surfaces 30, 38, and 48, it may overflow from the bonding surfaces 30, 38, and 48. Therefore, relief grooves 32, 40, and 50 are formed around the bonding surfaces 30, 38, and 48, and adhesive that overflows from the bonding surfaces 30, 38, and 48 to the inner or outer periphery is accommodated in the relief grooves 32, 40, and 50. This prevents the adhesive from overflowing into portions of the recess 26 other than the inner peripheral bonding portion 36 and the central joint portion 44 (the cooling channel 58, described below), thereby preventing adverse effects on the flow of heat transfer medium in the cooling channel 58, described below, for example. In this embodiment, the position determining portions 34, 42, 52 are provided so as to surround the relief grooves 32, 40, 50, making it difficult for the adhesive to overflow beyond the relief grooves 32, 40, 50 and further outward.

[0055] The resin plate 14 and the metal plate 12, which are bonded together by the adhesive layer 54, are pin-joined at their central portions. That is, a pin 56 is inserted from above into the insertion hole 18 that penetrates the metal plate 12 and the insertion hole 46 that penetrates the resin plate 14. Then, for example, the shank of the pin 56, which protrudes below the resin plate 14, is compressed and crushed in the axial direction, thereby increasing its diameter. The metal plate 12 and the resin plate 14 are positioned relative to each other between the tip of the enlarged shank of the pin 56 and the head of the pin 56, and the pin 56 is prevented from slipping out of the insertion holes 18, 46. In this way, the central region of the resin plate 14 is connected to the metal plate 12 by direct bonding with the pin 56, without the adhesive layer 54 interposed therebetween.

[0056] An annular positioning portion 52a is formed around the insertion hole 46 of the resin plate 14, and the positioning portion 52a and the metal plate 12 are overlapped in a state of direct contact without the use of adhesive. As a result, the central region of the resin plate 14 is mechanically and directly joined to the metal plate 12 by the pin 56 without the adhesive layer 54 interposed therebetween. The resin plate 14 and the metal plate 12 are positioned relative to each other at the direct joint portion formed by the pin 56, and relative displacement due to differences in linear expansion coefficients, as described below, is prevented. In this embodiment, the direct joint portion where the metal plate 12 and the resin plate 14 are directly joined by the pin 56 is provided at only one location in the center of each resin plate 14.

[0057] The metal plate 12 and the resin plate 14 are bonded together with an elastic adhesive layer 54 in an outer peripheral region of the resin plate 14 that is located on the outer side of the central region where the central joint 44 is provided. The metal plate 12 and the resin plate 14 are directly joined and fixedly connected by a pin 56 in the central region where the central joint 44 is provided. The directly joined central region is defined by a position defining portion 52a in the central joint 44 and the insertion hole 46. It is desirable that the projected area of ​​the central region in the up-down direction be sufficiently smaller than that of the resin plate 14, and the outer diameter of the position defining portion 52a, which is the outer diameter of the central region, is preferably 30 mm or less, and more preferably 10 mm or less.

[0058] In this embodiment, four resin plates 14, 14, 14, 14 arranged in the front-to-rear direction are attached to one metal plate 12. Each resin plate 14 is connected to the metal plate 12 by adhesion with an adhesive layer 54 in the outer periphery and by direct bonding with a pin 56 in the central region.

[0059] The metal plate 12 is placed on the upper surface of the resin plate 14, thereby covering the opening of the recess 26. This forms a cooling flow path 58 between the metal plate 12 and the resin plate 14, through which a heat transfer medium for cooling flows. The cooling flow path 58 is connected to the inner holes of the port members 20 at both left and right ends, and the heat transfer medium for cooling is supplied to and discharged from an external flow path (not shown) connected to the port member 20 via the port member 20. A pump, a refrigerator, or the like (not shown) is connected to the external flow path, and the heat transfer medium circulates through a circulation path formed by the cooling flow path 58 and the external flow path, changing its temperature through heat exchange. Specifically, for example, a heat transfer medium cooled by a refrigerator is supplied to the cooling flow path 58 through one port member 20, and the heat transfer medium, whose temperature increases as it flows through the cooling flow path 58 while exchanging heat with a battery pack (described later), is then discharged to the external flow path through the other port member 20. In this embodiment, a plurality of inner peripheral adhesive portions 36a, 36b are provided within the recess 26, and a cooling flow path 58 extending in the left-right direction is formed by overlapping the metal plate 12 and the resin plate 14. Note that the external flow path only needs to be provided with a mechanism for lowering the temperature of the high-temperature heat medium, and for example, an air-cooling device such as a radiator or a liquid-cooling device can be provided instead of a refrigerator.

[0060] The cooling heat exchanger 10 is mounted and used in an electrically powered vehicle such as an electric vehicle or a hybrid car. When the cooling heat exchanger 10 is mounted on the vehicle, a battery pack B to be cooled is placed on the portion of the metal plate 12 that overlaps with the resin plate 14, as shown in FIGS. 3 and 4 . The battery pack B may be placed directly on the metal plate 12, but is preferably placed on the metal plate 12 without any gaps, using a heat-conductive gap filler, heat-conductive sheet, or the like, interposed therebetween. The battery pack B is cooled by the cooling heat exchanger 10 by exchanging heat between the battery pack B and a heat medium flowing through the cooling flow passage 58 via the metal plate 12.

[0061] Depending on the vehicle's operating environment, the cooling heat exchanger 10 may be used in a high-temperature environment. In such cases, a difference in deformation occurs between the metal plate 12 made of metal and the resin plate 14 made of synthetic resin due to the difference in linear expansion coefficients. In the cooling heat exchanger 10, the metal plate 12 and the resin plate 14 are bonded together at the outer periphery of the resin plate 14 with an elastic adhesive layer 54 and are directly joined at the central region of the resin plate 14 with pins 56 without the adhesive layer 54. This structure restricts relative displacement between the metal plate 12 and the resin plate 14 at the central region of the resin plate 14, while allowing relative displacement at the outer periphery of the resin plate 14 due to elastic deformation of the adhesive layer 54. This allows sufficient relative displacement, particularly in the planar direction, due to the difference in linear expansion coefficients. Therefore, warping of the cooling heat exchanger 10 due to the difference in the linear expansion coefficients of the interconnected metal plate 12 and resin plate 14 is prevented, and peeling of the metal plate 12 and resin plate 14 due to rupture of the adhesive layer 54 is also less likely to occur.

[0062] In particular, because the metal plate 12 and the resin plate 14 are directly bonded to each other and positioned in the central region, the maximum length from the directly bonded portion to the outer circumferential edge of the resin plate 14 is relatively small. This reduces the difference in deformation amount due to the difference in the linear expansion coefficients of the metal plate 12 and the resin plate 14, effectively suppressing warping of the cooling heat exchanger 10, damage to the adhesive layer 54, and misalignment between the metal plate 12 and the resin plate 14.

[0063] In this embodiment, four plastic plates 14, 14, 14, 14 are attached to one metal plate 12. This reduces the size of each plastic plate 14, and shortens the maximum length from the central joint 44 provided in the central region of the plastic plate 14 to the outer peripheral edge of the plastic plate 14. Therefore, the difference in deformation amount due to the difference in linear expansion coefficient between the metal plate 12 and the plastic plate 14 is more effectively suppressed.

[0064] The upper surfaces of the positioning portions 34, 42, 52 of the resin plate 14 abut against the metal plate 12, thereby accurately setting the thickness d of the adhesive layer 54 formed between the bonding surfaces 30, 38, 48 and the metal plate 12. This stabilizes the amount of relative displacement between the metal plate 12 and the resin plate 14 permitted by the elasticity of the adhesive layer 54, and more effectively prevents problems such as warping of the cooling heat exchanger 10 due to differences in the linear expansion coefficients of the metal plate 12 and the resin plate 14.

[0065] The Young's modulus of the adhesive layer 54 is preferably 500 MPa or less, and more preferably 100 MPa or less, so that relative displacement due to the difference in linear expansion coefficient between the metal plate 12 and the resin plate 14 caused by elastic deformation of the adhesive layer 54 is sufficiently tolerated, thereby preventing warping of the cooling heat exchanger 10 and damage to the adhesive layer 54.

[0066] The outer diameter of the position defining portion 52a, which constitutes the central region in the narrow sense that is directly joined by the pin 56, is preferably 30 mm or less, and more preferably 10 mm or less. By making the area ratio of the central region in the resin plate 14 sufficiently small in this manner, the deformation constraint region in the resin plate 14 is narrowed. As a result, a large area is secured for the outer peripheral region that is permitted to move relative to the metal plate 12, preventing warping of the cooling heat exchanger 10 and damage to the adhesive layer 54 due to differences in the linear expansion coefficients of the metal plate 12 and the resin plate 14.

[0067] Fig. 6 shows a cooling heat exchanger 60 according to a second embodiment of the present invention. As shown in Fig. 7, the cooling heat exchanger 60 has a structure in which a metal plate 62 made of metal as a cooling surface component and a resin plate 14 made of synthetic resin as a flow path component are stacked one on top of the other in the vertical direction. In the following description, components and parts that are substantially the same as those in the first embodiment are denoted by the same reference numerals in the drawings, and description thereof will be omitted.

[0068] The metal plate 62 has a shorter length in the front-to-rear direction than the metal plate 12 of the first embodiment, and has approximately the same front-to-rear length as the resin plate 14. Therefore, the metal plate 62 has a rectangular shape that is longer in the left-to-right direction when viewed from above. The metal plate 62 has an insertion hole 18 formed in only one location, in the center. The metal plate 62 has through holes (not shown) formed in diagonal corners. A port member 20 is attached to the portion of the metal plate 62 where each through hole is formed.

[0069] The metal plate 62 is superimposed on the resin plate 14 from above, and as in the first embodiment, the metal plate 62 is bonded in the outer peripheral region with an elastic adhesive, and is directly joined in the central region without an adhesive layer by a pin 56 inserted into the insertion hole 18. In this embodiment, one resin plate 14 is attached to one metal plate 62 by being superimposed on it.

[0070] As shown in this embodiment, the cooling heat exchanger 60 can also be configured using one metal plate 62 and one resin plate 14. In this case, by making the metal plate 62 and the resin plate 14 relatively small, warping of the cooling heat exchanger 60 and peeling of the adhesive due to differences in linear expansion coefficients can be prevented. Note that it is also possible to configure a large cooling heat exchanger with a small number of parts using one metal plate and one resin plate by stacking one large resin plate instead of the four resin plates 14, 14, 14, 14, on the large metal plate (12) shown in the first embodiment.

[0071] Although the embodiments of the present invention have been described in detail above, the present invention is not limited to the specific description. For example, the direct bonded portion may be provided in a central region of a synthetic resin flow path member that is closer to the inner periphery than the outer periphery where the adhesive layer is provided, and multiple direct bonded portions may be provided in the central region.

[0072] In the first and second embodiments, pin joints are used as an example of the direct joint structure of the direct joint portion, but the direct joint structure of the direct joint portion is not limited to pin joints. Specifically, for example, a joint structure using bolts 72 and nuts 74 can be used, as in the cooling heat exchanger 70 shown in Fig. 8. Furthermore, for example, a direct joint structure can be formed by melting the overlapping surface of a synthetic resin flow path member with a cooling surface component by using a laser or frictional heat to weld the flow path member and the cooling surface component.

[0073] The adhesive relief portion is not limited to the groove shape shown in the first and second embodiments, and may be any shape that is spaced apart from the cooling surface component and forms an adhesive storage area between it and the cooling surface component. The adhesive relief portion may be provided, for example, on the same plane as the adhesive surface so as to extend outside the adhesive surface, or may be formed on a surface that is closer to the cooling surface component than the adhesive surface.

[0074] The shape of the cooling flow path is not limited to the linear shape shown in the above embodiment, and may be, for example, a spiral shape, a planar double spiral shape, a serpentine shape, etc. Furthermore, protrusions or the like may be provided in the cooling flow path to facilitate agitation of the heat transfer medium flowing through the cooling flow path.

[0075] The shapes of the flow path member and the cooling surface constituent member in a plan view are not particularly limited, and may be rectangular, square, various polygonal shapes, circular shapes, etc. Furthermore, the sizes of the flow path member and the cooling surface constituent member are set appropriately depending on, for example, the size of the object to be cooled, etc.

[0076] The object to be cooled is not limited to the battery pack B exemplified in the first embodiment, but may be, for example, a control device including an electronic circuit or the like as a heat generating element.

[0077] REFERENCE SIGNS LIST 10 Cooling heat exchanger (first embodiment) 12 Metal plate (cooling surface component) 14 Resin plate (flow path component) 16 Lightening hole 18 Insertion hole 20 Port component 22 Flange-shaped component 24 Anti-removal protrusion 26 Recess 28 Outer peripheral bonding portion 30 Bonding surface 32 Relief groove (adhesive relief portion) 34 Position determining portion 34a Position determining portion 34b Position determining portion 36 Inner peripheral bonding portion 36a Inner peripheral bonding portion 36b Inner peripheral bonding portion 38 Bonding surface 40 Relief groove (adhesive relief portion) 42 Position determining portion 44 Central bonding portion (direct bonding portion) 46 Insertion hole 48 Bonding surface 50 Relief groove (adhesive relief portion) 50a Relief groove (adhesive relief portion) 50b Relief groove (adhesive relief portion) 52 Position determining portion 52a Position determining portion 52b Position determining portion 54 Adhesive layer 56 Pin 58 Cooling flow path 60 Cooling heat exchanger (second embodiment) 62 Metal plate (cooling surface component) 70 Cooling heat exchanger (another embodiment) 72 Bolt 74 Nut B Battery pack (cooling target)

Claims

1. A heat exchanger for cooling, having a laminated structure in which a metal cooling surface component superposed on a cooling object and a synthetic resin flow path component are superposed on each other, and a cooling flow path through which a heat medium for cooling flows is formed between the superposed surfaces of the cooling surface component and the flow path component, wherein the cooling surface component and the flow path component are adhered to each other by an adhesive layer having elasticity in an outer peripheral region, and are fixed to each other by direct joining without an adhesive at a direct joining portion provided in a central region of the flow path component.

2. The heat exchanger for cooling according to claim 1, wherein an adhesive surface to which an adhesive is applied to form the adhesive layer is provided at an adhered portion of the flow path component with the cooling surface component, and a position defining portion that protrudes toward the cooling surface component side from the adhesive surface and defines the thickness of the adhesive layer is provided around the adhesive surface.

3. The heat exchanger for cooling according to claim 2, wherein an adhesive escape portion that allows the adhesive constituting the adhesive layer to overflow is provided between the adhesive surface and the position defining portion, between the superposed surfaces of the flow path component and the cooling surface component.

4. The heat exchanger for cooling according to claim 2 or 3, wherein the adhesive escape portion is continuously provided over the entire circumference around the adhesive surface, and the position defining portion is continuously provided over the entire circumference around the adhesive escape portion.

5. The heat exchanger for cooling according to any one of claims 1 to 4, wherein a plurality of the flow path components are superposed on one cooling surface component, and the direct joining portions are respectively provided in the central regions of the flow path components.

6. The heat exchanger for cooling according to any one of claims 1 to 5, wherein one flow path component is superposed on one cooling surface component.

7. The heat exchanger for cooling according to any one of claims 1 to 6, wherein the direct joining portion is provided only at one location in the center of the flow path component.

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