Heat exchanger

Abstract

Provided is a heat exchanger having a novel structure in which a lower plate and an upper plate are appropriately brazed together by efficient heating.　A heat exchanger 10 cools and / or heats an object 50 to be temperature-regulated, by heat exchange with a heat exchange fluid flowing through an internal flow passage 46. Outer peripheral portions of a lower plate 12 and an upper plate 14, which are stacked on one another, are provided with outer peripheral joined portions 40a, 40b joined to each other by brazing. Portions of the lower plate 12 and the upper plate 14 that are located outward of the outer peripheral joined portions 40a, 40b are provided with outer peripheral separated portions 30a, 30b separated from each other. At least one of the outer peripheral separated portion 30a of the lower plate 12 and the outer peripheral joined portion 40b of the upper plate 14 serves as an outer peripheral heat-receiving portion 60a (60b) that is disposed on a heat-transfer member 52a (52b) and is heated by heat transferred from the heat-transfer member 52a (52b) subjected to induction heating.

Description

Heat Exchanger

[0001] The present invention relates to a heat exchanger used for cooling and / or heating, for example, batteries of electrified vehicles.

[0002] Conventionally, heat exchangers used for cooling and / or heating batteries of electrified vehicles are known. Like the cooling structure disclosed in Japanese Patent No. 7553866 (Patent Document 1), for example, the heat exchanger has a structure in which a press-formed member formed with a groove portion and a flat flow path upper lid stacked on the press-formed member so as to cover the groove portion are fixed to each other by brazing. The cooling fluid flows through the flow path formed between the press-formed member and the flow path upper lid by utilizing the groove portion, whereby heat exchange occurs between the battery pack superimposed on the cooling surface of the flow path upper lid and the cooling fluid, and thus the battery pack is cooled.

[0003] Japanese Patent No. 7553866

[0004] Incidentally, as described in Patent Document 1, the press-formed member serving as a lower plate and the flow path upper lid serving as an upper plate are brazed and fixed to each other by heating the brazing filler metal arranged between the overlapping surfaces of the press-formed member and the flow path upper lid. Patent Document 1 exemplifies heating by a heating furnace as a general means for heating the brazing filler metal.

[0005] However, as pointed out in Patent Document 1, brazing using a heating furnace requires large-scale equipment, so problems such as an increase in manufacturing cost are likely to occur. In addition, not only the brazed portion but also the entire base material accommodated in the heating furnace is heated, which results in increased energy required for brazing.

[0006] One of the heating methods used in brazing is induction heating, which utilizes electromagnetic induction. Induction heating has advantages such as lower energy consumption compared to heating using a heating furnace and easier miniaturization of equipment compared to heating furnaces that house and heat the entire base material. However, with induction heating, it is difficult to heat the entire brazed area almost uniformly, which can lead to variations in the fixing strength between the lower plate and the upper plate, or misalignment of the relative position and orientation of the lower plate and the upper plate. In particular, temperature differences tend to occur between the brazed areas at the outer edges and the inner edges of the lower and upper plates, and the above-mentioned problems due to temperature differences during brazing could be a concern.

[0007] The problem to be solved by the present invention is to provide a novel heat exchanger structure in which the lower plate and the upper plate are properly brazed together by efficient heating.

[0008] The following describes preferred embodiments for understanding the present invention. However, each embodiment described below is illustrative and can be combined with others as appropriate. Furthermore, the multiple components described in each embodiment can be recognized and adopted as independently as possible, and can be combined with any component described in another embodiment as appropriate. Thus, the present invention is not limited to the embodiments described below, and various other embodiments can be realized.

[0009] The first embodiment is a heat exchanger that has a channel through which a heat exchange fluid flows, and cools and / or heats a temperature-controlled object by heat exchange with the heat exchange fluid flowing through the channel, wherein a lower plate has a recess forming the channel in its inner circumference and an upper plate has a heat exchange surface for the temperature-controlled object, and these are superimposed on each other, and outer peripheral fixing portions are provided on the outer circumference of the lower plate and the upper plate, fixed to each other by brazing, and outer peripheral separation portions are provided on the lower plate and the upper plate that are separated from each other on the outer peripheral fixing portion side, and at least one of the outer peripheral separation portion on the lower plate and the outer peripheral fixing portion on the upper plate is an outer peripheral heat receiving portion that is heated by the heat transferred from the heat transfer member when superimposed on the heat transfer member that is induced to heat.

[0010] According to the heat exchanger structured in this embodiment, an outer peripheral heat receiving section is provided on at least one outer peripheral portion of the lower plate and the upper plate. By heating at least one outer peripheral portion of the lower plate and the upper plate, it is possible to prevent insufficient heating of the brazing material placed between the overlapping surfaces of the lower plate and the upper plate in the outer peripheral portion, thereby achieving stable brazing even in the outer peripheral portion.

[0011] When heating the lower plate, heating the outer peripheral separation portion allows the outer peripheral fixing portion adjacent to the outer peripheral separation portion to be heated from both the inner and outer sides, achieving a heating state closer to that of other fixing portions on the inner side.

[0012] When heating the upper plate, the presence of an outer peripheral separation ensures that the heat received by the outer peripheral fixing portion from the upper plate side is transferred equally to both the inner and outer peripheral sides of the outer peripheral fixing portion, thereby suppressing variations in the heating state of the outer peripheral fixing portion.

[0013] The second embodiment is a heat exchanger described in the first embodiment, wherein the outer peripheral separation portion of the lower plate is provided with a projection that protrudes from the outer peripheral fixing portion in a direction away from the upper plate, and a flange-like portion that protrudes outward is provided on the tip side of the projection of the projection portion in the outer peripheral separation portion.

[0014] According to the heat exchanger structured in this embodiment, by making the outer peripheral separation portion of the lower plate in which the recess is formed a shape consisting of an inclined projection portion and a flange-like portion, the shape of the outer peripheral side of the outer peripheral fixing portion in which the outer peripheral separation portion is formed can be made to approximate the shape of the inner peripheral side of the outer peripheral fixing portion in which the recess is formed. Therefore, the difference between the heating state of the outer peripheral fixing portion and the heating state of the other fixing portions is reduced, and the heating state of each fixing portion is stabilized.

[0015] When the outer peripheral separation portion of the lower plate is used as the outer peripheral heat receiving portion, the presence of a flange-like portion in the outer peripheral separation portion ensures a sufficient contact area between the outer peripheral separation portion and the heat transfer member.

[0016] The third embodiment is a heat exchanger described in the first or second embodiment, wherein the outer peripheral fixing portion is in the shape of a flat plate.

[0017] In a heat exchanger with a structure according to this embodiment, the flat shape of the outer peripheral fixing portion makes it easier to secure a large brazing area between the lower plate and the upper plate. In addition, when brazing the outer peripheral fixing portion, misalignment between the lower plate and the upper plate is less likely to occur.

[0018] Furthermore, when a heat transfer component is superimposed on the upper plate, the flat shape of the outer peripheral fixing portion of the upper plate makes it easier to bring the heat transfer component into contact with the outer peripheral fixing portion, allowing for efficient transfer of heat from the heat transfer component to the brazed outer peripheral fixing portion.

[0019] The fourth embodiment is a heat exchanger described in any one of the first to third embodiments, wherein the lower plate is a plate-shaped member of substantially constant thickness.

[0020] According to the heat exchanger structured in this embodiment, the lower plate is made of a plate-like member of substantially constant thickness, which allows the lower plate to be easily manufactured by pressing or other methods of plate material.

[0021] The fifth embodiment is a heat exchanger described in any one of the first to fourth embodiments, wherein the flow path comprises parallel flow path sections arranged in the flow path width direction, the lower plate and the upper plate are superimposed on each other and brazed at a partition wall section that divides the parallel flow path section, and the walls at both ends of the flow path width direction in these parallel flow path sections constitute the outer circumferential fixing section.

[0022] According to the heat exchanger structured in this embodiment, since an outer peripheral separation portion is provided on the outer peripheral side of the outer peripheral fixing portion, the difference in shape between the inner peripheral fixing portion, which is composed of partition walls separating the parallel flow channels, and the outer peripheral fixing portion, which is composed of both end walls in the flow channel width direction of the parallel flow channels, can be reduced, thereby reducing the difference in heating conditions between the inner peripheral fixing portion and the outer peripheral fixing portion.

[0023] The sixth embodiment is a heat exchanger described in any one of the first to fifth embodiments, wherein the brazing material used to braze the lower plate and the upper plate is a low-melting-point brazing material having a melting point in the range of 520 to 580°C.

[0024] According to the heat exchanger structure in this embodiment, the heating temperature of the heat transfer member can be made relatively low, thereby reducing the energy required for induction heating, and preventing damage to the lower plate and / or upper plate superimposed on the heat transfer member due to high temperatures.

[0025] The low melting point of the brazing material makes it less likely for the brazing material to fail to melt properly, even when it is heated by the heat transferred from the induction-heated heat transfer member during brazing. Furthermore, by using a brazing material that melts at a relatively low temperature, a wide temperature range can be obtained in which the brazing material melts without damaging the lower plate and / or upper plate due to high heat. Therefore, a wider range of temperature variation in the heat transfer member can be tolerated, making heating control easier and stabilizing the quality of the brazing fixation.

[0026] According to the present invention, in a heat exchanger, the lower plate and the upper plate can be properly brazed by efficient heating.

[0027] Figure 1 shows an exploded perspective view of a heat exchanger as a first embodiment of the present invention. Figure 1 shows a plan view of the lower plate constituting the heat exchanger. Figure 1 shows a cross-sectional view of the heat exchanger shown in Figure 1, corresponding to the III-III section in Figure 2. Figure 3 shows the IV-IV section. Figure 1 shows a flowchart showing the manufacturing process of the heat exchanger shown in Figure 1. Figure 5 shows an exploded perspective view of the object to be heated in the manufacturing process of the heat exchanger. Figure 6 shows a plan view of the object to be heated. Figure 7 shows the VIII-VIII section. Figure 7 shows the IX-IX section. Figure 7 shows the X-X section. Figure 5 shows a diagram showing the induction heating process in the manufacturing process of the heat exchanger, with the heating coil positioned at the left end of the object to be heated. Figure 5 shows a diagram showing the induction heating process in the manufacturing process of the heat exchanger, with the heating coil positioned at the right end of the object to be heated.

[0028] Embodiments of the present invention will be described below with reference to the drawings.

[0029] Figures 1 to 4 show a heat exchanger 10 as a first embodiment of the present invention. The heat exchanger 10 has a structure in which a lower plate 12 and an upper plate 14 are overlapped and fixed to each other. In the following description, as a general rule, the vertical direction refers to the vertical direction on the plane of the paper in Figure 3, which is the direction in which the lower plate 12 and the upper plate 14 are overlapped; the horizontal direction refers to the horizontal direction on the plane of the paper in Figure 3, which is the length direction of the flow path 46, which will be described later; and the front-back direction refers to the vertical direction on the plane of the paper in Figure 2, which is the width direction of the flow path 46, which will be described later.

[0030] The lower plate 12 is preferably made of a synthetic resin mixed with metal or a heat conductive filler. The lower plate 12 is made of, for example, an aluminum alloy or stainless steel, and in this embodiment, it is made of an aluminum alloy to reduce weight. The lower plate 12 is a plate-like member with a substantially uniform thickness throughout, and in this embodiment, it is a pressed metal fitting. The lower plate 12 has a recess 16 that opens on its upper surface. The peripheral wall of the recess 16 is composed of an outer peripheral wall portion 18 that extends continuously around the entire outer circumference of the lower plate 12 and protrudes upward.

[0031] The recess 16 of the lower plate 12 is provided with a partition wall portion 20 that protrudes upward from the bottom wall portion. The partition wall portion 20 extends linearly in the left-right direction, and multiple portions (four in this embodiment) are provided in parallel, separated from each other in the front-rear direction. The left and right ends of the partition wall portion 20 do not reach the outer peripheral wall portion 18, and are separated inward in the left-right direction from the left and right sides of the outer peripheral wall portion 18. With the formation of multiple partition wall portions 20 in this manner, the portions of the recess 16 located to the left and right of the partition wall portion 20 are formed as continuous junction portions 22, 22 in the front-rear direction. Through holes 24 are formed in each of the junction portions 22, 22, penetrating the bottom wall portion in the vertical direction. The positions of the through holes 24, 24 in the junction portions 22, 22 are not particularly limited, but in this embodiment, the through hole 24 of the left junction portion 22 and the through hole 24 of the right junction portion 22 are arranged diagonally across the lower plate 12.

[0032] In the recess 16, between adjacent partition wall portions 20, 20 in the front-rear direction, and between adjacent outer peripheral wall portion 18 and partition wall portion 20 in the front-rear direction, grooves 26 extending linearly in the left-right direction are formed. Multiple protrusions 28 are formed on the bottom wall portion of the groove 26 in the lower plate 12. The protrusions 28 are substantially V-shaped in a plan view of the lower plate 12 shown in Figure 2, and extend inclined to the right from the center in the front-rear width direction of the groove 26 to both sides. In this embodiment, the protrusions 28 are provided throughout the width direction of the groove 26, and both ends in the front-rear direction are integrally connected to the side wall portion of the groove 26. In this embodiment, the protrusions 28 are not provided on the left side portion of the groove 26, but only on the right side portion. Furthermore, the bottom wall of the groove 26 widens approximately perpendicular to the vertical direction in the right portion where the projection 28 is formed, and in the left portion where the projection 28 is not formed, it slopes upward as it moves to the right, so that the depth of the left portion of the groove 26 becomes shallower as it moves to the right. Consequently, the left confluence portion 22, which is continuously provided at the left end of the groove 26, is deeper in the vertical direction than the right confluence portion 22, which is continuously provided at the right end of the groove 26.

[0033] As shown in enlarged view in Figures 3 and 4, the outer peripheral wall portion 18 of the lower plate 12 is provided to protrude upward in a stepped manner relative to the bottom wall portion of the recess 16, and the protruding tip surface is an annular plane that extends continuously in the circumferential direction with a certain width dimension. An outer peripheral separation portion 30a is provided on the outer peripheral side of the outer peripheral wall portion 18 of the lower plate 12, protruding downward. The outer peripheral separation portion 30a is provided to be separated downward from the protruding tip surface (upper surface) of the outer peripheral wall portion 18. The outer peripheral separation portion 30a integrally includes a protruding portion 32 that protrudes downward from the outer peripheral end of the outer peripheral wall portion 18, and a flange-like portion 34 that protrudes outward in an orthogonal direction from the lower end of the protruding portion 32 toward the outer peripheral side. By providing such an outer peripheral separation portion 30a, the deformation rigidity of the plate-like lower plate 12 is improved.

[0034] The protruding portion 32 of the outer peripheral separation portion 30a has a shape that substantially corresponds to the portion connecting the protruding tip of the outer peripheral wall portion 18 and the bottom wall portion of the recess 16. Furthermore, the flange-like portion 34 of the outer peripheral separation portion 30a has a shape that substantially corresponds to the portion connecting the bottom wall portion of the recess 16 with the outer peripheral wall portion 18. Therefore, as shown in Figures 3 and 4, the outer peripheral end of the lower plate 12, which is composed of the outer peripheral wall portion 18 and the outer peripheral separation portion 30a, has a cross-sectional shape that is substantially symmetrical between the inner and outer peripheral portions.

[0035] The partition wall portion 20 has substantially the same cross-sectional shape as the outer peripheral end of the lower plate 12, which is composed of the outer peripheral wall portion 18 and the outer peripheral separation portion 30a, and the front and rear portions have substantially symmetrical cross-sectional shapes. The protruding tip surface of the partition wall portion 20 is located on the same vertically orthogonal plane as the protruding tip surface of the outer peripheral wall portion 18.

[0036] The upper plate 14 is made of a synthetic resin mixed with metal or a heat conductive filler. The upper plate 14 is made of, for example, an aluminum alloy or stainless steel, and in this embodiment, it is made of an aluminum alloy to reduce weight. As shown in Figure 1, the upper plate 14 has a substantially rectangular flat plate shape, and as shown in Figures 3 and 4, the upper surface is a heat exchange surface 36 that comes into contact with the battery pack 50, which will be described later.

[0037] As shown in Figures 3 and 4, the upper plate 14 of this embodiment is a clad plate with a brazing material layer 38 on its lower surface. The brazing material layer 38 is made of a material with a lower melting point than the lower plate 12 and the upper plate 14. For example, an alloy of iron, manganese, magnesium, and copper is preferably used, but it can be formed using various conventionally known brazing materials. It is desirable that the brazing material layer 38 be made of a low-melting-point brazing material with a melting point in the range of 520 to 580°C.

[0038] The upper plate 14 is superimposed on the upper surface of the lower plate 12 and covers the recess 16 of the lower plate 12. The outer peripheral wall portion 18 and partition wall portion 20 of the lower plate 12 and the upper plate 14 are superimposed in a state of contact with each other, and are fixed to each other by brazing at the superimposed portion.

[0039] As described above, in this embodiment, the outer peripheral fixing portion 40a, which is the fixing portion on the lower plate 12 side by brazing, is formed by the outer peripheral wall portion 18 of the lower plate 12. Also, the outer peripheral fixing portion 40b, which is the fixing portion on the upper plate 14 side by brazing, is formed by the overlapping portion with the outer peripheral wall portion 18 of the upper plate 14. The outer peripheral fixing portions 40a and 40b in this embodiment extend in a substantially rectangular annular shape along the outer peripheral edges of the lower plate 12 and the upper plate 14.

[0040] In this embodiment, the inner circumferential fixing portion 42a, which is the fixing portion on the lower plate 12 side by brazing, is formed by the partition wall portion 20 of the lower plate 12. Similarly, the inner circumferential fixing portion 42b, which is the fixing portion on the upper plate 14 side by brazing, is formed by the overlapping portion with the partition wall portion 20 of the upper plate 14. The inner circumferential fixing portions 42a and 42b in this embodiment extend linearly in the left-right direction.

[0041] The outer peripheral separation portion 30a of the lower plate 12 has a protruding portion 32 that protrudes from the outer peripheral fixing portion 40a in a direction away from the upper plate 14, and is separated downward from the outer peripheral end of the upper plate 14. As a result, the outer peripheral separation portion 30b on the upper plate 14 side is separated upward from the outer peripheral separation portion 30a of the lower plate 12. The flange-like portion 34 of the outer peripheral separation portion 30a of the lower plate 12 is located approximately parallel to the outer peripheral separation portion 30b of the upper plate 14, separated by approximately a constant distance.

[0042] A fluid-filled region 44, separated from the outside, is formed using the recess 16 by brazing the outer peripheral fixing portion 40a of the lower plate 12 and the outer peripheral fixing portion 40b of the upper plate 14. In addition, the left and right intermediate portions of the fluid-filled region 44 are formed into a parallel flow path section 48, in which multiple flow paths 46 are arranged in parallel in the flow path width direction by brazing the inner peripheral fixing portion 42a of the lower plate 12 and the inner peripheral fixing portion 42b of the upper plate 14, utilizing the groove 26. The multiple flow paths 46 in the parallel flow path section 48 are separated by partition wall portions 20 that constitute the inner peripheral fixing portion 42a. Furthermore, the walls of the flow paths 46 located at both the front and rear ends of the parallel flow path section 48 are composed of partition wall portions 20 that constitute the inner peripheral fixing portion 42a and outer peripheral wall portions 18 that constitute the outer peripheral fixing portion 40a.

[0043] The heat exchanger 10, constructed by brazing a lower plate 12 and an upper plate 14 together, has through holes 24, 24 on the left and right sides that are connected to an external circuit (not shown). A heat exchange fluid, such as water, is supplied from the external circuit to the fluid-filled region 44 through the left through hole 24, and the heat exchange fluid is discharged from the fluid-filled region 44 to the external circuit through the right through hole 24. This causes the heat exchange fluid to flow through the flow path 46 from left to right. The temperature of the heat exchange fluid is regulated in the external circuit, and as it flows through the flow path 46 in contact with the upper plate 14, it regulates the temperature of the upper plate 14.

[0044] As shown in Fig. 4, a battery pack 50 as a temperature control target is attached to the heat exchange surface 36 of the upper plate 14 in the heat exchanger 10. The temperature of the battery pack 50 is adjusted by heat exchange between the upper plate 14 cooled or heated by a heat exchange fluid and the battery pack 50. In short, heat exchange via the upper plate 14 occurs between the heat exchange fluid flowing through the flow path 46 and the battery pack 50, so that the battery pack 50 is cooled and / or heated.

[0045] In the upstream portion of the flow path 46, the cross-sectional area of the flow path decreases toward downstream. Further, a projection 28 is provided in the downstream portion of the flow path 46, and the heat exchange fluid flowing through the flow path 46 is agitated by the projection 28, whereby the temperature difference of the heat exchange fluid in the flow path depth direction is reduced. Due to these features, in the heat exchanger 10, the temperature difference between the heat exchange fluid and the battery pack 50 is sufficiently large even in the downstream portion of the flow path 46, and the heat exchanger 10 exhibits effective cooling / heating performance for the battery pack 50.

[0046] In the present embodiment, the battery pack 50 is overlapped in a state of being in direct contact with the heat exchange surface 36 of the upper plate 14. However, for example, a heat-conductive heat conductive sheet or heat conductive gel may be interposed between the battery pack 50 and the heat exchange surface 36 of the upper plate 14, so that the battery pack 50 and the heat exchange surface 36 of the upper plate 14 are indirectly in contact with each other via the heat conductive sheet or the like. By providing such a heat conductive sheet or the like, a slight gap between the battery pack 50 and the upper plate 14 is filled with the heat conductive sheet or the like, thereby improving heat exchange efficiency.

[0047] The heat exchanger 10 of the present embodiment functions as a heating device that increases the temperature of the battery pack 50 by causing a heat exchange fluid having a higher temperature than the battery pack 50 to flow through the flow path 46, and on the other hand, functions as a cooler that decreases the temperature of the battery pack 50 by causing a heat exchange fluid having a lower temperature than the battery pack 50 to flow through the flow path 46. For example, the flow path 46 may be selectively connectable to an external circuit that supplies / discharges high-temperature heat exchange fluid and an external circuit that supplies / discharges low-temperature heat exchange fluid, and the heat exchanger 10 may selectively exhibit a function as a heating device and a function as a cooling device by switching the external circuit connected to the flow path 46. However, the heat exchanger 10 may have only a function as a cooler. Further, the temperature control target is not limited to the battery pack 50.

[0048] Incidentally, the heat exchanger 10 is manufactured by a manufacturing method including steps according to the flowchart shown in FIG. 5. That is, first, in step (hereinafter, S) 1, the lower plate 12 and the upper plate 14 are prepared. The lower plate 12 is formed into a predetermined shape including the above-described recess 16 by pressing a base plate of aluminum alloy. The upper plate 14 is prepared as a flat plate of aluminum alloy provided with a brazing filler metal layer 38.

[0049] Next, in S2, the first heat transfer member 52a and the second heat transfer member 52b are prepared. As shown in Figure 6, the first and second heat transfer members 52a and 52b each integrally include a rectangular annular outer heat transfer portion 54 corresponding to the outer peripheral fixing portions 40a and 40b, and a plurality of linear inner heat transfer portions 56 corresponding to the inner peripheral fixing portions 42a and 42b. As can be seen from the fact that the plurality of inner heat transfer portions 56 have shapes corresponding to the inner peripheral fixing portions 42a and 42b, they are separated from each other in the front-rear direction, and are also separated inward in the front-rear direction from both the front and rear sides of the outer heat transfer portion 54. It is desirable that the first heat transfer member 52a be made of a material that has a higher heating efficiency by induction heating than the lower plate 12, and is made of stainless steel, for example, which has a higher heating efficiency by induction heating than aluminum alloy. In addition, the first heat transfer member 52a can be made of a carbon material such as graphite to reduce weight. The second heat transfer member 52b is preferably made of a material that has a higher induction heating efficiency than the upper plate 14, and is made of stainless steel, for example, which has a higher induction heating efficiency than aluminum alloy. Furthermore, the second heat transfer member 52b can be made of a carbon material such as graphite to reduce its weight. The first heat transfer member 52a and the second heat transfer member 52b are only required to be made of materials that have conductivity and appropriate electrical resistance and are excellent in induction heating efficiency, and may be made of different materials.

[0050] The first and second heat transfer members 52a and 52b, made of stainless steel, can be prepared in S2, for example, by punching out a stainless steel sheet to form an outer peripheral heat transfer portion 54 and a plurality of inner peripheral heat transfer portions 56. The first and second heat transfer members 52a and 52b, made of carbon material, are formed into a predetermined shape during pressurization and sintering during manufacturing. In this embodiment, the left-right width dimensions of the left and right sides of the outer peripheral heat transfer portion 54 of the second heat transfer member 52b are larger than the left-right width dimensions of the left and right sides of the outer peripheral heat transfer portion 54 of the first heat transfer member 52a, and the length of the second heat transfer member 52b in the left-right direction is longer than that of the first heat transfer member 52a.

[0051] Next, in S3, the lower plate 12 and the upper plate 14 are stacked on top of each other, with the first heat transfer member 52a stacked on the lower surface of the lower plate 12 and the second heat transfer member 52b stacked on the upper surface of the upper plate 14 to form the object to be heated 58. When the first and second heat transfer members 52a and 52b are made of stainless steel, it is desirable to interpose a heat-conducting buffer member 59 between the overlapping surfaces of the first heat transfer member 52a and the lower plate 12, and between the overlapping surfaces of the second heat transfer member 52b and the upper plate 14, as shown in Figures 9 and 10. The heat-conducting buffer member 59 is, for example, a plate-shaped member made of carbon material and has a shape corresponding to the first and second heat transfer members 52a and 52b. By providing the heat-conducting buffer member 59, it is possible to allow efficient heat transfer from the first and second heat transfer members 52a and 52b to the lower plate 12 and upper plate 14 during the brazing process described later, while preventing damage to the lower plate 12 and upper plate 14 due to direct contact between the first and second heat transfer members 52a and 52b. If the first and second heat transfer members 52a and 52b are made of carbon material, the heat-conducting buffer member 59 can be omitted to reduce the number of parts while preventing damage to the lower plate 12 and upper plate 14.

[0052] In the object to be heated 58, the first heat transfer member 52a and the second heat transfer member 52b are superimposed on the lower plate 12 and upper plate 14 from both the upper and lower sides, sandwiching the lower plate 12 and upper plate 14 which are superimposed on each other, as shown in Figures 7 to 10.

[0053] In the object to be heated 58, the outer peripheral heat transfer portion 54 of the first heat transfer member 52a is superimposed on the outer peripheral fixing portion 40a of the lower plate 12, as shown in Figures 7 to 10, straddling the outer peripheral fixing portion 40a, and overlapping the outer peripheral side and inner peripheral side of the outer peripheral fixing portion 40a. The first heat transfer member 52a is superimposed on the outer peripheral side of the outer peripheral fixing portion 40a in contact with the flange-shaped portion 34 of the outer peripheral separation portion 30a, and is superimposed on the inner peripheral side of the outer peripheral fixing portion 40a in contact with the bottom wall of the recess 16. Therefore, both the outer peripheral side (outer peripheral separation portion 30a) and the inner peripheral side of the outer peripheral fixing portion 40a superimposed on the first heat transfer member 52a are outer peripheral heat receiving portions 60a that are heated by receiving heat transferred from the induction-heated first heat transfer member 52a.

[0054] In the object to be heated 58, the outer peripheral heat transfer portion 54 of the second heat transfer member 52b is superimposed on the outer peripheral fixing portion 40b of the upper plate 14. Therefore, the outer peripheral fixing portion 40b superimposed on the second heat transfer member 52b is used as the outer peripheral heat receiving portion 60b that is heated by receiving heat transferred from the second heat transfer member 52b which is induced to heat. The outer peripheral heat transfer portion 54 superimposed on the upper plate 14 may be superimposed only on the outer peripheral fixing portion 40b, or it may be superimposed on the inner and / or outer peripheral sides beyond the outer peripheral fixing portion 40b.

[0055] In the object to be heated 58, the inner heat transfer portion 56 of the first heat transfer member 52a straddles the inner fixing portion 42a of the lower plate 12 and overlaps with the bottom wall portion of the flow path 46 (groove 26) on both the front and rear outer sides of the inner fixing portion 42a. Therefore, the portions that have come off on both the front and rear outer sides of the inner fixing portion 42a that are overlapped with the first heat transfer member 52a are all considered to be the inner heat receiving portions 62a that receive heat from the first heat transfer member 52a.

[0056] In the object to be heated 58, the inner circumferential heat transfer portion 56 of the second heat transfer member 52b is superimposed on the inner circumferential fixing portion 42b of the upper plate 14. Therefore, the inner circumferential fixing portion 42b superimposed on the second heat transfer member 52b serves as the inner circumferential heat receiving portion 62b that receives heat from the second heat transfer member 52b. The inner circumferential heat transfer portion 56 superimposed on the upper plate 14 may be superimposed only on the inner circumferential fixing portion 42b, or it may be superimposed on the front, rear and outward and / or left and right outward from the inner circumferential fixing portion 42b.

[0057] Next, in S4, the object to be heated 58 is set on the support base 66 of the induction heating device 64. The induction heating device 64 includes a heating coil 68 that forms a magnetic field when energized, and a support base 66 that supports the object to be heated 58 so that it can be inserted into the heating coil 68. The induction heating device 64 then induces heating of the object to be heated 58 by inserting the object to be heated 58, which is set on the support base 66, into the energized heating coil 68. The method of fixing the object to be heated 58 to the support base 66 is not particularly limited, but in this embodiment, both left and right ends of the second heat transfer member 52b, which protrudes outward on both the left and right sides than the first heat transfer member 52a, are placed on the support base 66 and fixed to the support base 66 by a fixing device (not shown).

[0058] More specifically, the induction heating device 64 includes a power supply unit 70 that outputs a high-frequency alternating current, a capacitor box 72 connected to the power supply unit 70, and a heating coil 68 through which the output current of the power supply unit 70 flows via the capacitor box 72. The induction heating device 64 also includes a temperature measuring instrument 74, such as a thermal camera equipped with a temperature sensor, which measures the temperature of the object to be heated 58 before and after induction heating by the heating coil 68.

[0059] The support base 66 is preferably made of an electrically insulating material, and it is desirable that the material is such that temperature rise due to induction heating is unlikely to occur. The support base 66 is capable of fixedly setting the object to be heated 58. The support portion of the object to be heated 58 is inserted into the heating coil 68, and the object to be heated 58 set on the support base 66 can be inserted into the heating coil 68 together with a part of the support base 66. The support base 66 is movable relative to the heating coil 68 in the axial direction (left-right direction) of the heating coil 68, and the insertion position into the heating coil 68 can be changed in the left-right direction. Therefore, by moving the support base 66 relative to the heating coil 68, the insertion portion of the object to be heated 58 set on the support base 66 into the heating coil 68 can be changed, and the heated portion of the object to be heated 58 can be changed in the left-right direction. The speed of the relative movement of the support base 66 with respect to the heating coil 68 is controlled by a control device (not shown) and is variable in this embodiment.

[0060] Next, in S5, current is supplied from the power supply unit 70 to the heating coil 68 via the capacitor box 72, and a magnetic field is formed by the heating coil 68. Then, the portion of the object to be heated 58 inserted into the heating coil 68 is heated by electromagnetic induction. For example, the temperature rise of the object to be heated 58 due to induction heating can also be controlled by controlling the magnitude of the current supplied from the power supply unit 70 to the heating coil 68, in other words, the output of the heating coil 68, using a control device (not shown).

[0061] Here, since the first and second heat transfer members 52a and 52b are made of a material that has higher induction heating efficiency compared to the lower plate 12 and upper plate 14, the portion inserted into the heating coil 68 becomes hotter than the lower plate 12 and upper plate 14. Then, heat is transferred from the high-temperature first and second heat transfer members 52a and 52b to the outer peripheral heat receiving portion 60a and inner peripheral heat receiving portion 62a of the lower plate 12, which is superimposed on the first and second heat transfer members 52a and 52b, and to the outer peripheral heat receiving portion 60b and inner peripheral heat receiving portion 62b of the upper plate 14, thereby heating the lower plate 12 and upper plate 14 with the heat transferred from the first and second heat transfer members 52a and 52b.

[0062] Next, in S6, while maintaining power supply to the heating coil 68, the support base 66 is moved relative to the heating coil 68, thereby gradually changing the heating area of ​​the object to be heated 58 by the heating coil 68 in the left-right direction. That is, the object to be heated 58 and the heating coil 68 move relative to each other by the sliding displacement of the support base 66, from the state in Figure 11A where the heating coil 68 is located at the left end of the object to be heated 58 to the state in Figure 11B where the heating coil 68 is located at the right end of the object to be heated 58. As a result, the entirety of the first and second heat transfer members 52a and 52b can be heated by the heating coil 68 positioned on a part of the object to be heated 58 in the left-right direction.

[0063] In addition, in S6, the support base 66 can be moved back and forth in the left-right direction relative to the heating coil 68 to heat the first and second heat transfer members 52a and 52b multiple times. Furthermore, temperature unevenness of the first and second heat transfer members 52a and 52b can be reduced by controlling the movement speed of the support base 66 relative to the heating coil 68 and the power supplied to the heating coil 68, for example, based on the temperature distribution of the first and second heat transfer members 52a and 52b measured by the temperature measuring instrument 74. Specifically, for example, when both ends in the left-right direction are inserted into the heating coil 68, moving the support base 66 faster relative to the heating coil 68 than when the middle part in the left-right direction is inserted into the heating coil 68 can prevent the ends in the left-right direction, which are prone to temperature rise, from becoming excessively hot.

[0064] Then, at the overlapping surface between the outer peripheral fixing portion 40a and inner peripheral fixing portion 42a of the lower plate 12, which have become hot due to the heat transferred from the first and second heat transfer members 52a and 52b that are induction heated, and the outer peripheral fixing portion 40b and inner peripheral fixing portion 42b of the upper plate 14, the brazing material layer 38 of the upper plate 14 melts. In this embodiment, the relative movement between the object to be heated 58 and the heating coil 68 in S6 makes it possible to melt the brazing material layer 38 of the upper plate 14 over the entire overlapping portion (heating target portion) between the outer peripheral fixing portion 40a and inner peripheral fixing portion 42a of the lower plate 12 and the outer peripheral fixing portion 40b and inner peripheral fixing portion 42b of the upper plate 14.

[0065] Thus, by employing induction heating as a heating method for melting the brazing material layer 38, it is possible to obtain superior effects such as miniaturization of heating equipment, reduction of heating equipment costs, improvement of energy efficiency, and reduction of heating time compared to heating using conventional heating furnaces such as Nocorok furnaces.

[0066] Furthermore, instead of directly heating the lower plate 12 and the upper plate 14 including the brazing material layer 38 by induction heating, the first and second heat transfer members 52a and 52b are induction heated, and the lower plate 12 and upper plate 14 are indirectly heated by the heat transferred from the heated first and second heat transfer members 52a and 52b. Therefore, even when the lower plate 12 and upper plate 14 are made of a material such as an aluminum alloy, which has relatively low induction heating efficiency, the brazing material layer 38 can be effectively melted without increasing the output of the induction heating device 64. As a result, the brazing equipment including the induction heating device 64 can be miniaturized, and the electrical energy required for brazing can be reduced.

[0067] The lower plate 12 has an outer peripheral separation portion 30a on the outer peripheral side of the outer peripheral fixing portion 40a, and the outer peripheral heat receiving portions 60a provided on the inner and outer peripheral sides of the outer peripheral fixing portion 40a are both in contact with the first heat transfer member 52a and overlap, receiving heat transferred from the first heat transfer member 52a. Therefore, the outer peripheral fixing portion 40a of the lower plate 12 is heated from both the inner and outer peripheral sides, reducing the temperature difference between the inner and outer portions, and allowing the overlapping portion of the brazing material layer 38 with the outer peripheral fixing portion 40a to melt stably.

[0068] Furthermore, since the lower plate 12 is provided with an outer peripheral separation portion 30a, the outer peripheral fixing portion 40a and its adjacent portion and the inner peripheral fixing portion 42a and its adjacent portion have substantially the same cross-sectional shape. Therefore, the heating and heat dissipation patterns of the outer peripheral fixing portion 40a and the inner peripheral fixing portion 42a become similar, and the outer peripheral fixing portion 40a and the inner peripheral fixing portion 42a can be brazed in the same manner. Since the lower plate 12 in this embodiment is a plate-like member with substantially a uniform thickness throughout, the difference in heating and heat dissipation patterns due to the difference in thickness between the outer peripheral fixing portion 40a and the inner peripheral fixing portion 42a is also reduced.

[0069] The upper plate 14 has an outer peripheral separation portion 30b on the outer peripheral side of the outer peripheral fixing portion 40b. As a result, the heat transferred from the second heat transfer member 52b to the outer peripheral fixing portion 40b is transferred similarly to the inner and outer peripheral sides of the outer peripheral fixing portion 40b in the upper plate 14. This makes the heating and heat dissipation patterns of the inner and outer peripheral portions of the outer peripheral fixing portion 40b similar, reducing the temperature difference between the inner and outer peripheral portions of the outer peripheral fixing portion 40b. Therefore, the brazing material layer 38 of the outer peripheral fixing portion 40b can be stably melted.

[0070] The outer peripheral fixing portion 40b of the upper plate 14 is a flat plate shape that extends substantially perpendicular to the vertical direction, and is pressed against the outer peripheral fixing portion 40a of the lower plate 12, which extends substantially perpendicular to the vertical direction, in the vertical direction and brazed. Therefore, during brazing, it is easy to press the outer peripheral fixing portion 40a of the lower plate 12 and the outer peripheral fixing portion 40b of the upper plate 14 against each other, and misalignment between the lower plate 12 and the upper plate 14 is less likely to occur.

[0071] Furthermore, since the upper plate 14 of this embodiment is flat overall, the area around the outer peripheral fixing portion 40b and the area around the inner peripheral fixing portion 42b have substantially the same cross-sectional shape. Therefore, the heating and heat dissipation patterns of the outer peripheral fixing portion 40b and the inner peripheral fixing portion 42b become similar, and the outer peripheral fixing portion 40b and the inner peripheral fixing portion 42b can be brazed in the same manner.

[0072] The brazing material layer 38 is formed of a low-melting-point brazing material with a melting point in the range of 520 to 580°C. Therefore, the lower plate 12 and upper plate 14 only need to be heated to a relatively low temperature, and can be heated to a sufficient temperature by the heat transferred from the first and second heat transfer members 52a and 52b. Furthermore, because the brazing material layer 38 has a low melting point, the temperature range of the brazing material layer 38 during brazing can be made wider, and the temperature variation of the first and second heat transfer members 52a and 52b after heating by induction heating can be tolerated over a larger temperature range. In addition, the induction heating of the first and second heat transfer members 52a and 52b can be done at a relatively low temperature, preventing damage to the lower plate 12 and upper plate 14 caused by pressing the high-temperature first and second heat transfer members 52a and 52b against them.

[0073] Next, after the brazing material layer 38 has been sufficiently heated, in S7, the power supply to the heating coil 68 is stopped, and the heating of the first and second heat transfer members 52a and 52b is stopped. Then, as the heated and melted brazing material layer 38 cools and solidifies, the lower plate 12 and the upper plate 14 are brazed to each other at the outer peripheral fixing portions 40a and 40b and the inner peripheral fixing portions 42a and 42b. After the heating of the brazing material layer 38 is complete, the object to be heated 58 may be removed from the support base 66, and the brazing material layer 38 may be cooled in a location separate from the support base 66.

[0074] Finally, in S8, the heat exchanger 10 can be obtained by removing the first and second heat transfer members 52a and 52b from the brazed lower plate 12 and upper plate 14. As described above, the heat exchanger 10 of this embodiment is manufactured by efficiently brazing the lower plate 12 and the upper plate 14 using induction heating.

[0075] Although embodiments of the present invention have been described in detail above, the present invention is not limited by its specific description. For example, a projection protruding from the bottom wall of the flow path is not essential in the present invention and can be omitted. Furthermore, when a projection is provided, the specific shape of the projection is not particularly limited and may be a shape that extends linearly in the width direction of the flow path, a hemispherical shape, a frustoconical shape, etc. The projection does not need to be provided along the entire width direction of the flow path, but may be provided only in the middle of the width direction of the flow path, or may be provided biased to one side of the width direction of the flow path. The projection may be provided along the entire length of the flow path, or may be provided partially in the length direction of the flow path. When multiple projections are provided, they may differ in shape (including size) and pitch in the length direction of the flow path.

[0076] In the first embodiment, a structure was shown in which a plurality of channels 46 are arranged in parallel in the parallel channel section 48. However, for example, the parallel channel section can also be formed in the middle portion of a single channel that extends in a meandering manner. Alternatively, for example, only a single channel extending linearly in one direction may be provided.

[0077] The outer peripheral fixing portion does not necessarily have to be continuous around the entire circumference. Specifically, for example, the lower plate and the upper plate may be partially separated in the circumferential direction, and a port for connecting the flow path to an external circuit may be provided in the separated portion. If the outer peripheral fixing portion is not provided around the entire circumference, the outer peripheral heat receiving portion may also be omitted in the portion where the outer peripheral fixing portion is not provided.

[0078] The upper plate is preferably flat in shape to obtain a flat heat exchange surface, but irregularities may be provided as appropriate. Specifically, for example, the upper plate may be bent into a continuous groove shape around its entire circumference at the outer peripheral separation portion for the purpose of improving bending deformation rigidity. Partition walls (inner peripheral fixing portion) that separate multiple flow paths are not essential in the lower plate. If partition walls are not provided in the lower plate, only one flow path may be provided. Alternatively, for example, a corrugated intermediate plate can be placed between the lower plate and the upper plate, and the fluid-filled region between the lower plate and the upper plate can be partitioned by the intermediate plate to form flow paths on both the lower plate side and the upper plate side. In this case, in addition to the upper surface of the upper plate, the lower surface of the lower plate also serves as a heat exchange surface.

[0079] The brazing material is not necessarily limited to being integrally provided as a brazing layer on the clad upper plate; for example, it can be placed separately between the overlapping surfaces of the lower plate and the upper plate. Alternatively, a brazing layer can be integrally provided on the upper plate by applying liquid brazing material to the upper plate with a spray or brush and allowing it to dry or solidify.

[0080] The shape of the heat transfer member is not limited, and may be a flat plate shape without an intermediate gap, such as the first and second heat transfer members 52a and 52b of the first embodiment. Alternatively, a heat transfer member on the lower plate side may be used, for example, that has a protruding portion that can contact the inner circumference fixing portion of the lower plate.

[0081] The heat transfer member superimposed on the lower plate (the first heat transfer member 52a in the first embodiment) and the heat transfer member superimposed on the upper plate (the second heat transfer member 52b in the first embodiment) may have different shapes from each other. That is, for example, the inner circumferential heat transfer portion of the heat transfer member on the lower plate side may be provided so as to cover substantially the entire bottom wall portion of the groove, and the inner circumferential heat transfer portion of the heat transfer member on the upper plate side may be provided at a position outside the groove so as to overlap the inner circumferential fixing portion.

[0082] In the first embodiment, an example was given of using both a first heat transfer member 52a superimposed on the lower plate 12 and a second heat transfer member 52b superimposed on the upper plate 14 as heat transfer members. However, the heat transfer members can also be limited to, for example, the first heat transfer member 52a superimposed on the lower plate 12, and only the second heat transfer member 52b superimposed on the upper plate 14. In short, the heat transfer members only need to be superimposed on at least one of the lower plate and the upper plate during brazing.

[0083] In the first embodiment, a structure was illustrated in which the support base 66 is movable relative to the fixedly provided heating coil 68, but the heating coil 68 may also be movable relative to the fixedly provided support base 66.

[0084] The control of the movement speed between the support base and the heating coil is not limited to the feedback control based on the temperature distribution exemplified in the first embodiment, but can also be controlled, for example, based on statistical information of data such as temperature distribution and heating efficiency that have been collected in advance.

[0085] The heating coil is not limited to one through which the object to be heated 58 is inserted, as shown in the first embodiment. For example, it may be arranged on both the upper and lower sides of the object to be heated 58, with the vertical direction being axial, so that the object to be heated 58 is inserted between the upper and lower heating coils.

[0086] 10 Heat exchanger (first embodiment) 12 Lower plate 14 Upper plate 16 Recess 18 Outer peripheral wall portion 20 Partition wall portion 22 Confluence portion 24 Through hole 26 Groove 28 Projection 30a, 30b Outer peripheral separation portion 32 Protruding portion 34 Flange-shaped portion 36 Heat exchange surface 38 Brazing material layer 40a, 40b Outer peripheral fixing portion 42a, 42b Inner peripheral fixing portion 44 Fluid sealed area 46 Flow path 48 Parallel flow path portion 50 Battery pack 52a First heat transfer member 52b Second heat transfer member 54 Outer peripheral heat transfer portion 56 Inner peripheral heat transfer portion 58 Object to be heated 59 Heat transfer buffer member 60a, 60b Outer peripheral heat receiving portion 62a, 62b Inner peripheral heat receiving portion 64 Induction heating device 66 Support base 68 Heating coil 70 Power supply unit 72 Capacitor box 74 Temperature measuring instrument

Claims

1. A heat exchanger having a flow path through which a heat exchange fluid flows, which cools and / or heats a temperature-controlled object by heat exchange with the heat exchange fluid flowing through the flow path, wherein a lower plate has a recess forming the flow path in its inner circumference and an upper plate has a heat exchange surface for the temperature-controlled object, and these are superimposed on each other, the outer circumference of the lower plate and the upper plate are provided with an outer peripheral fixing portion fixed to each other by brazing, the outer circumference of the lower plate and the upper plate is provided with an outer peripheral separation portion that is separated from each other on the outer circumference side of the outer peripheral fixing portion, and at least one of the outer peripheral separation portion of the lower plate and the outer peripheral fixing portion of the upper plate is an outer peripheral heat receiving portion that is heated by the heat transferred from the heat transfer member by being superimposed on the heat transfer member that is induction heated.

2. The heat exchanger according to claim 1, wherein the outer peripheral separation portion of the lower plate is provided with a projection that protrudes from the outer peripheral fixing portion in a direction away from the upper plate, and a flange-like portion that protrudes toward the outer periphery is provided on the tip side of the projection of the projection portion in the outer peripheral separation portion.

3. The heat exchanger according to claim 1 or 2, wherein the outer peripheral fixing portion is in the shape of a flat plate.

4. The heat exchanger according to any one of claims 1 to 3, wherein the lower plate is a plate-shaped member of substantially constant thickness.

5. The heat exchanger according to any one of claims 1 to 4, wherein the flow path comprises parallel flow path sections arranged in the flow path width direction, the lower plate and the upper plate are superimposed on each other and brazed at a partition wall section that divides the parallel flow path section, and the walls at both ends of the flow path width direction in the parallel flow path section constitute the outer circumferential fixing section.

6. The heat exchanger according to any one of claims 1 to 5, wherein the brazing material used to braze the lower plate and the upper plate is a low-melting-point brazing material having a melting point in the range of 520 to 580°C.

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