Method for manufacturing heat exchanger

Abstract

Provided is a method for manufacturing a heat exchanger having a novel structure and with which it is possible to braze a lower plate and an upper plate by efficient heating.　The method for manufacturing a heat exchanger includes the steps of: (a) preparing a lower plate 12 and an upper plate 14 that overlap each other and form a flow path 46 therein; (b) preparing a conductive heat transfer member 52; and (c) arranging the lower plate 12, the upper plate 14, and the heat transfer member 52 that overlap each other so as to be movable relative to a heating coil 64 of an induction heating device 62 that inductively heats the heat transfer member 52, and moving the lower plate 12, the upper plate 14, and the heat transfer member 52 relative to the heating coil 64 while partially inductively heating the heat transfer member 52 in the relative movement direction by means of the heating coil 64, thereby brazing the overlapping surfaces of the lower plate 12 and the upper plate 14 by transfer heat from the heat transfer member 52.

Description

Method for manufacturing a heat exchanger

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

[0002] Conventionally, heat exchangers used for cooling batteries of electrified vehicles and the like are known. Like the cooling structure disclosed in Japanese Patent No. 7553866 (Patent Document 1), for example, the heat exchanger comprises a press-formed member provided with a groove, and a flat flow path cover plate stacked on the press-formed member so as to cover the groove, which are fixed to each other by brazing. A coolant flows through the flow path formed between the press-formed member and the flow path cover plate by utilizing the groove, whereby heat exchange occurs between the battery pack stacked on the cooling surface of the flow path cover plate and the coolant, and 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 cover plate serving as an upper plate are brazed and fixed to each other by heating the brazing filler metal disposed between the overlapping surfaces of the press-formed member and the flow path cover plate. 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, and thus problems such as an increase in manufacturing cost are likely to occur. In addition, not only the brazed portion but 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 consuming less energy than heating using a heating furnace and being easier to miniaturize compared to heating furnaces that house and heat the entire base material. However, since the materials of the lower plate and upper plate, which are the base materials for brazing, are selected considering factors such as weight, corrosion resistance, and cost, it is conceivable that some materials may not be suitable for induction heating, as it is difficult to raise the temperature through electromagnetic induction. In such cases, the amount of energy required to heat the lower plate and upper plate to a suitable temperature for brazing may increase, or problems may arise such as insufficient temperature rise due to induction heating of the lower plate and upper plate, resulting in improper brazing and fixation.

[0007] The problem to be solved by the present invention is to provide a method for manufacturing a heat exchanger with a novel structure that allows the lower plate and the upper plate to be brazed 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 method for manufacturing a heat exchanger, comprising: (a) preparing a lower plate and an upper plate that are superimposed on each other to form a flow path inside; (b) preparing a conductive heat transfer member; and (c) arranging the superimposed lower plate, upper plate and heat transfer member so as to be movable relative to a heating coil of an induction heating device that induction heats the heat transfer member, and moving the lower plate, upper plate and heat transfer member relative to the heating coil while partially induction heating the heat transfer member by the heating coil in the direction of relative movement, thereby brazing the overlapping surfaces of the lower plate and upper plate by heat transferred from the heat transfer member.

[0010] According to the heat exchanger manufacturing method in this embodiment, the lower plate and upper plate are heated by the heat transferred from the induction-heated heat transfer member, and the lower plate and upper plate are brazed together. Therefore, even if the lower plate and upper plate are made of materials that are difficult to induction heat, by using a heat transfer member made of a material with high induction heating efficiency, the lower plate and upper plate can be efficiently brazed together using induction heating.

[0011] When induction heating a heat transfer component, instead of heating the entire component simultaneously, the component is moved while partially heating it, thereby scanning and heating the entire component. This allows for miniaturization of the induction heating device while effectively heating the entire brazed area.

[0012] A second embodiment is a method for manufacturing a heat exchanger as described in the first embodiment, wherein a recess constituting the flow path is formed in at least one of the lower plate and the upper plate, and the heat transfer member is superimposed on the bottom wall portion of the recess in the lower plate and / or the upper plate.

[0013] When a recess is formed in at least one of the lower plate and the upper plate, the brazed portion becomes the wall of the recess outside the recess. However, if a heat transfer member is to be superimposed on the portion outside the recess, it becomes necessary to insert the heat transfer member into the recess between the recesses, which can easily lead to problems such as complexity of the heat transfer member's shape, reduced durability, and misalignment due to differences in thermal expansion coefficients between the lower plate and / or upper plate and the heat transfer member. Therefore, according to the heat exchanger manufacturing method according to this embodiment, by superimposing the heat transfer member onto the bottom wall of the recess, the shape of the heat transfer member is simplified, superimposing of the heat transfer member is made easier, and relative displacement between the heat transfer member and the lower plate and / or upper plate due to differences in thermal expansion coefficients can be tolerated.

[0014] A third embodiment is a method for manufacturing a heat exchanger as described in the second embodiment, wherein the recess is formed in the lower plate, a flat plate portion is formed in the upper plate that covers the recess and extends to the brazed portion with the lower plate, and the heat transfer member is superimposed on the upper plate at a position away from the recess.

[0015] According to the heat exchanger manufacturing method in this embodiment, the heat transfer member is superimposed on the upper plate at a position away from the recess, allowing the heat transfer member to be positioned closer to the brazed portion between the lower plate and the upper plate, and enabling efficient heating of the brazed portion by the heat transferred from the heat transfer member.

[0016] Since the brazed portion of the lower plate, including the part outside the recess, is superimposed on the flat portion of the upper plate, it is easy to superimpose the heat transfer member onto the upper plate at the brazed portion, and it is easy to secure a large area for heat transfer from the heat transfer member to the upper plate. Furthermore, because the brazed portion of the upper plate to the lower plate is flat, the area of ​​the brazed portion is secured, and a sufficiently large fixing strength between the lower plate and the upper plate can be obtained.

[0017] The fourth embodiment is a method for manufacturing a heat exchanger described in any one of the first to third embodiments, wherein the speed of relative movement between the heat transfer member and the heating coil can be controlled.

[0018] By increasing the relative speed of movement between the heat transfer member and the heating coil, the temperature rise of the heat transfer member can be suppressed, while by decreasing the relative speed of movement between the heat transfer member and the heating coil, the temperature of the heat transfer member can be increased further. Therefore, according to the heat exchanger manufacturing method according to this embodiment, the temperature distribution of the induction-heated heat transfer member can be made uniform by controlling the relative speed of movement between the heat transfer member and the heating coil.

[0019] The fifth aspect is a method for manufacturing a heat exchanger as described in the fourth aspect, wherein the speed of relative movement of the heating coil with respect to the heat transfer member is made faster at both ends of the lower plate and the upper plate in the relative movement direction than at the intermediate portion of the lower plate and the upper plate excluding both ends of the relative movement direction.

[0020] According to the heat exchanger manufacturing method in this embodiment, since the temperature of both ends of the lower plate and upper plate is easily increased by induction heating, the temperature difference between the ends and the intermediate portion in the direction of relative movement can be suppressed by increasing the speed of relative movement of the heat transfer member with respect to the heating coil when heating both ends of the lower plate and upper plate.

[0021] The sixth aspect is a method for manufacturing a heat exchanger described in any one of the first to fifth aspects, wherein the current flowing through the heating coil is controllable.

[0022] According to the heat exchanger manufacturing method in this embodiment, the temperature rise of the heat transfer member can be suppressed by reducing the current flowing through the heating coil, and the temperature of the heat transfer member can be increased further by increasing the current flowing through the heating coil. Therefore, by controlling the current flowing through the heating coil, it becomes easier to make the temperature distribution of the induction-heated heat transfer member more uniform.

[0023] The seventh embodiment is a method for manufacturing a heat exchanger described in any one of the first to sixth embodiments, wherein the heat transfer member is prepared by forming it from a material that has a higher induction heating efficiency than the lower plate and the upper plate.

[0024] According to the heat exchanger manufacturing method in this embodiment, even if the lower plate and upper plate are made of materials with low induction heating efficiency, the lower plate and / or upper plate can be effectively heated and brazed by the heat transferred from the heat transfer member which is efficiently heated by induction heating.

[0025] The eighth aspect is a method for manufacturing a heat exchanger as described in the seventh aspect, wherein the lower plate and the upper plate are prepared by being formed from an aluminum alloy, and the heat transfer member is prepared by being formed from stainless steel.

[0026] According to the heat exchanger manufacturing method in this embodiment, the lower plate and upper plate are made of aluminum alloy, thereby reducing the weight of the heat exchanger.

[0027] By using stainless steel for the heat transfer components, higher induction heating efficiency can be achieved compared to lower and upper plates made of aluminum alloy. Furthermore, even when stainless steel heat transfer components are directly heated to high temperatures by induction heating, a decrease in durability is less likely to be a problem, and deformation due to thermal expansion is kept relatively small.

[0028] The ninth aspect is a method for manufacturing a heat exchanger as described in the eighth aspect, wherein a heat-conducting buffer member is provided between the overlapping surfaces of the lower plate and / or the upper plate and the heat transfer member.

[0029] According to the heat exchanger manufacturing method in this embodiment, by interposing a heat-conductive buffer member between the lower plate and / or upper plate and the heat transfer member, it is possible to prevent damage to the lower plate and / or upper plate caused by direct contact with the stainless steel heat transfer member while allowing sufficient heat transfer from the heat transfer member.

[0030] The tenth aspect is a method for manufacturing a heat exchanger as described in the seventh aspect, wherein the heat transfer member is prepared by forming it from a carbon material.

[0031] According to the heat exchanger manufacturing method in this embodiment, the heat transfer members are made of a carbon material such as graphite, thereby reducing the weight and cost of the heat transfer members. Furthermore, heat transfer members made of carbon material are less likely to damage the lower plate and / or upper plate even when they are directly superimposed on and in contact with the lower plate and / or upper plate, compared to heat transfer members made of metal.

[0032] The eleventh aspect is a method for manufacturing a heat exchanger described in any one of the first to tenth aspects, wherein the outer peripheral fixing portion provided on the outer periphery of the lower plate and the upper plate is fixed by brazing, and the outer peripheral portions of the lower plate and the upper plate are separated from each other from the outer peripheral portion.

[0033] In the heat exchanger manufacturing method according to this embodiment, if the outermost brazing portion, which is the outermost part to be fixed, is located at the outer edge of the lower plate and the upper plate, the difference in heating state between the outermost part to be fixed and the other inner parts to be fixed becomes large during brazing. Therefore, by separating the lower plate and the upper plate on the outer side of the outermost part to be fixed, the difference in heating state between the outermost part to be fixed and the other inner parts to be fixed during brazing can be reduced, thereby achieving stable brazing by uniformizing the temperature of these inner and outer parts to be fixed.

[0034] The twelfth aspect is a method for manufacturing a heat exchanger described in any one of the first to eleventh aspects, wherein the lower plate and the upper plate are brazed together with a low-melting-point brazing material having a melting point in the range of 520 to 580°C.

[0035] According to the heat exchanger manufacturing method 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 the lower plate and / or upper plate superimposed on the heat transfer member from being damaged by high heat.

[0036] 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.

[0037] According to the present invention, when manufacturing a heat exchanger, the lower plate and the upper plate can be brazed by efficient heating.

[0038] 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.

[0039] Embodiments of the present invention will be described below with reference to the drawings.

[0040] 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.

[0041] 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.

[0042] 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.

[0043] Between the front-rear direction adjacent partition wall portions 20, 20 in the recess 16, and between the front-rear direction adjacent outer peripheral wall portion 18 and the partition wall portion 20, there are respectively formed recessed grooves 26 that extend linearly in the left-right direction. A plurality of protrusions 28 are formed on the bottom wall portion of the recessed 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 FIG. 2, and extend obliquely rightward toward both sides from the center in the front-rear width direction of the recessed groove 26. In the present embodiment, the protrusions 28 are provided over the entire width direction of the recessed groove 26, and both end portions in the front-rear direction are integrally connected to the side wall portions of the recessed groove 26. In the present embodiment, the protrusions 28 are not provided on the left side portion of the recessed groove 26, but only on the right side portion. The bottom wall portion of the recessed groove 26 extends substantially orthogonal to the vertical direction in the right side portion where the protrusions 28 are formed, and is inclined upward toward the right in the left side portion where no protrusion 28 is formed, so that the depth of the left side portion of the recessed groove 26 becomes shallower as it goes toward the right. Therefore, the left joining portion 22 continuously provided at the left end of the recessed groove 26 has a greater depth in the vertical direction than the right joining portion 22 continuously provided at the right end of the recessed groove 26.

[0044] As shown enlarged in FIGS. 3 and 4, the outer peripheral wall portion 18 of the lower plate 12 is provided to protrude upward in a stepped shape with respect to the bottom wall portion of the recess 16, and a protruding distal end surface thereof is an annular flat surface that continuously extends in the circumferential direction with a certain width dimension. An outer peripheral spacing portion 30a protruding downward is provided on the outer peripheral side of the outer peripheral wall portion 18 in the lower plate 12. The outer peripheral spacing portion 30a is provided so as to be spaced downward relative to the protruding distal end surface (upper surface) of the outer peripheral wall portion 18. The outer peripheral spacing portion 30a is integrally provided with a protruding portion 32 that protrudes downward from the outer peripheral end of the outer peripheral wall portion 18, and a flange-shaped portion 34 that protrudes in the vertical orthogonal direction toward the outer periphery from the lower end portion of the protruding portion 32. By providing such an outer peripheral spacing portion 30a, the deformation rigidity of the lower plate 12 formed as a plate-shaped member is improved.

[0045] The protruding portion 32 of the outer peripheral spaced portion 30a has a shape substantially corresponding to a portion connecting the protruding tip end of the outer peripheral wall portion 18 and the bottom wall portion of the recessed portion 16. Further, the flange-shaped portion 34 of the outer peripheral spaced portion 30a has a shape substantially corresponding to a connection portion between the bottom wall portion of the recessed portion 16 and the outer peripheral wall portion 18. Accordingly, as shown in Figures 3 and 4, the outer peripheral end portion of the lower plate 12 constituted by the outer peripheral wall portion 18 and the outer peripheral spaced portion 30a has a cross-sectional shape in which the inner peripheral portion and the outer peripheral portion are substantially symmetrical.

[0046] The partition wall portion 20 has substantially the same cross-sectional shape as the outer peripheral end portion of the lower plate 12 constituted by the outer peripheral wall portion 18 and the outer peripheral spaced portion 30a, and has a cross-sectional shape in which the front portion and the rear portion are substantially symmetrical. Note that 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.

[0047] The upper plate 14 is formed of metal, synthetic resin mixed with thermally conductive filler, or the like. The upper plate 14 is formed of, for example, an aluminum alloy or stainless steel, and in the present embodiment, is formed of an aluminum alloy to achieve weight reduction. 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 thereof serves as a heat exchange surface 36 in contact with a battery pack 50 described later.

[0048] As shown in Figures 3 and 4, the upper plate 14 of the present embodiment is a clad plate whose lower surface is constituted by a brazing filler metal layer 38. The brazing filler metal layer 38 is formed of a material having 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 suitably employed, but various conventionally known brazing filler metals can be used to form the layer. It is desirable that the brazing filler metal layer 38 is formed of a low-melting-point brazing filler metal having a melting point within the range of 520 to 580°C.

[0049] The upper plate 14 is superimposed on the upper surface of the lower plate 12 and covers the recessed portion 16 of the lower plate 12. The outer peripheral wall portion 18 and the partition wall portion 20 of the lower plate 12, and the upper plate 14 are superimposed on each other in a mutually abutting state, and are fixed to each other at the superimposed portion by brazing.

[0050] 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.

[0051] 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.

[0052] 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.

[0053] 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.

[0054] 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.

[0055] As shown in Figure 4, a battery pack 50, which is the object to be temperature controlled, 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 controlled by heat exchange between the upper plate 14, which is cooled or heated by the heat exchange fluid, and the battery pack 50. In short, heat exchange occurs between the heat exchange fluid flowing through the flow path 46 and the battery pack 50 via the upper plate 14, causing the battery pack 50 to be cooled and / or heated.

[0056] In the upstream portion of the flow path 46, the cross-sectional area of ​​the flow path decreases towards the downstream portion. Furthermore, 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, thereby reducing the temperature difference of the heat exchange fluid in the depth direction of the flow path. As a result, the heat exchanger 10 maintains a sufficiently large temperature difference between the heat exchange fluid and the battery pack 50 even in the downstream portion of the flow path 46, and exhibits effective cooling / heating performance for the battery pack 50.

[0057] In this embodiment, the battery pack 50 is placed on top of the upper plate 14 in direct contact with the heat exchange surface 36. However, for example, a heat-conducting thermal conductive sheet or thermal 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 via the thermal conductive sheet or the like. By providing such a thermal conductive sheet or the like, the small gap between the battery pack 50 and the upper plate 14 is filled with the thermal conductive sheet or the like, thereby improving the heat exchange efficiency.

[0058] The heat exchanger 10 of this embodiment functions as a heating device to raise the temperature of the battery pack 50 by flowing a heat exchange fluid at a higher temperature than the battery pack 50 through the flow path 46, while also functioning as a cooler to lower the temperature of the battery pack 50 by flowing a heat exchange fluid at a lower temperature than the battery pack 50 through the flow path 46. For example, the flow path 46 may be selectively connectable to an external circuit that supplies / discharges a high-temperature heat exchange fluid and an external circuit that supplies / discharges a low-temperature heat exchange fluid, and the heat exchanger 10 may selectively perform the functions of a heating device and a cooling device by switching the external circuit connected to the flow path 46. However, the heat exchanger 10 may only have the function of a cooler. Furthermore, the object to temperature control is not limited to the battery pack 50.

[0059] Incidentally, the heat exchanger 10 is manufactured by a manufacturing method that includes the steps shown in the flowchart in Figure 5. Specifically, first, in step (hereinafter referred to as S) 1, the lower plate 12 and the upper plate 14 are prepared. The lower plate 12 is prepared in a predetermined shape with the recess 16 as described above by press-forming an aluminum alloy sheet. The upper plate 14 is prepared as a flat aluminum alloy sheet with a brazing layer 38.

[0060] Next, in S2, a conductive first heat transfer member 52a and a 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 peripheral 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.

[0061] 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.

[0062] 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.

[0063] 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.

[0064] 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.

[0065] 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.

[0066] 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.

[0067] 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.

[0068] In this embodiment, the outer peripheral fixing portion 40b and inner peripheral fixing portion 42b of the upper plate 14, onto which the second heat transfer member 52b is superimposed, are flat plate-shaped portions, ensuring a sufficient contact area with the second heat transfer member 52b. Furthermore, since 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 are flat plate shapes that extend in a direction perpendicular to the superimposing direction, misalignment between the lower plate 12 and the upper plate 14 is less likely to occur during brazing.

[0069] 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).

[0070] 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.

[0071] 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.

[0072] 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).

[0073] 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.

[0074] 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.

[0075] 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.

[0076] 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.

[0077] 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.

[0078] 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.

[0079] 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.

[0080] 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.

[0081] 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.

[0082] 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.

[0083] 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.

[0084] 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.

[0085] Next, after sufficient heating of the brazing material layer 38 is completed, 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, 40b and the inner peripheral fixing portions 42a, 42b. In this embodiment, the outer peripheral fixing portion 40a on the lower plate 12 and the outer peripheral fixing portion 40b on the upper plate 14 before brazing are designated as outer peripheral fixing portions, and these outer peripheral fixing portions are fixed to each other by brazing in the brazing process from S5 to S7. Similarly, in this embodiment, the inner circumferential fixing portion 42a on the lower plate 12 and the inner circumferential fixing portion 42b on the upper plate 14 before brazing are designated as the inner circumferential fixing portions, and the inner circumferential fixing portions are fixed to each other by brazing in the brazing process of S7. The outer circumferential portion 30a, 30b is the outer circumferential separation portion 30a, 30b, which separates the lower plate 12 and the upper plate 14 from each other after brazing. 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 place other than the support base 66.

[0086] 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.

[0087] 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.

[0088] 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.

[0089] 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.

[0090] 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.

[0091] 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.

[0092] 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.

[0093] 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.

[0094] 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.

[0095] In the first embodiment, a structure was illustrated in which the support base 66 is movable relative to the fixedly mounted heating coil 68, but the heating coil 68 may also be movable relative to the fixedly mounted support base 66. Furthermore, the support structure for the object to be heated in the induction heating device is not particularly limited, and for example, a pair of support bases fixed to support parts extending from the heat transfer member to both the left and right sides may be provided at positions away from the object to be heated on both sides.

[0096] 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.

[0097] 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.

[0098] 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 method for manufacturing a heat exchanger, comprising the steps of: preparing a lower plate and an upper plate that are superimposed on each other to form a flow path inside; preparing a conductive heat transfer member; and arranging the superimposed lower plate, upper plate and heat transfer member so as to be movable relative to a heating coil of an induction heating device that induction heats the heat transfer member, and while partially induction heating the heat transfer member by the heating coil in the direction of relative movement, moving the lower plate, upper plate and heat transfer member relative to the heating coil, thereby brazing the overlapping surfaces of the lower plate and upper plate by heat transferred from the heat transfer member.

2. A method for manufacturing a heat exchanger according to claim 1, wherein a recess constituting the flow path is formed in at least one of the lower plate and the upper plate, and the heat transfer member is superimposed on the bottom wall portion of the recess in the lower plate and / or the upper plate.

3. The method for manufacturing a heat exchanger according to claim 2, wherein a flat plate portion extending to the brazed portion with the lower plate is formed on the upper plate, and the heat transfer member is superimposed on the flat plate portion of the upper plate.

4. A method for manufacturing a heat exchanger according to any one of claims 1 to 3, wherein the speed of relative movement between the heat transfer member and the heating coil can be controlled.

5. The method for manufacturing a heat exchanger according to claim 4, wherein the speed of relative movement of the heating coil with respect to the heat transfer member is made faster at both ends of the lower plate and the upper plate in the relative movement direction than at the intermediate portion of the lower plate and the upper plate excluding both ends of the relative movement direction.

6. A method for manufacturing a heat exchanger according to any one of claims 1 to 5, wherein the current flowing through the heating coil can be controlled.

7. A method for manufacturing a heat exchanger according to any one of claims 1 to 6, wherein the heat transfer member is prepared by forming it from a material that has a higher induction heating efficiency than the lower plate and the upper plate.

8. The method for manufacturing a heat exchanger according to claim 7, wherein the lower plate and the upper plate are prepared by being formed from an aluminum alloy, and the heat transfer member is prepared by being formed from stainless steel.

9. The method for manufacturing a heat exchanger according to claim 8, wherein a heat-conducting buffer member is disposed between the overlapping surfaces of the lower plate and / or the upper plate and the heat transfer member.

10. The method for manufacturing a heat exchanger according to claim 7, wherein the heat transfer member is prepared by being formed from a carbon material.

11. A method for manufacturing a heat exchanger according to any one of claims 1 to 10, wherein the outer peripheral fixing portion provided on the outer peripheral portion of the lower plate and the upper plate is fixed by brazing, and the outer peripheral portions of the lower plate and the upper plate are separated from each other.

12. A method for manufacturing a heat exchanger according to any one of claims 1 to 11, wherein the lower plate and the upper plate are brazed together with a low-melting-point brazing material having a melting point in the range of 520 to 580°C.

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