Heat exchanger and method for manufacturing heat exchanger

Abstract

A heat exchanger is provided with a first plate member, a second plate member, and a plurality of joining portions. The first plate member faces the battery. The second plate member is disposed so as to face the first plate member, and a flow path through which the heat exchange medium passes is formed between the second plate member and the first plate member. The plurality of joining portions are portions where the first plate member and the second plate member are joined by welding, and each of the plurality of joining portions has one of a plurality of weld lines extending in a first direction and arranged in a second direction orthogonal to the first direction to divide the flow path. Among the plurality of welding lines, the welding line located closer to the first plate member side than the neutral axis is set as a first welding line, and the welding line located closer to the second plate member side than the neutral axis is set as a second welding line. The sum of the shortest distances from the neutral axis to the first weld line and the sum of the shortest distances from the neutral axis to the second weld line are substantially the same.

Description

Technical Field

[0001] The present disclosure relates to a heat exchanger and a method for manufacturing the heat exchanger. Background Art

[0002] In the Japanese Patent Gazette No. 2020-510534, a heat exchanger for cooling a battery mounted on an electric vehicle by heat exchange with the battery is disclosed. The heat exchanger has two plate-like components joined by laser beam welding, and a flow path formed between the two plate-like components and through which a heat exchange medium passes. The flow path is divided by a plurality of joints, which are the parts where the two plate-like components are joined, and are arranged in an orthogonal direction orthogonal to the flow direction of the heat exchange medium. In the Japanese Patent Gazette No. 2020-510534, a structure is disclosed, in which a plurality of joints are arranged on a neutral axis extending in an orthogonal direction in a cross section along the orthogonal direction of the heat exchanger. Moreover, in the Japanese Patent Gazette No. 2020-510534, a structure is disclosed, in which a plurality of joints are arranged away from the neutral axis on a cooling surface of a plate-like component opposite to the battery, which contacts the battery and extends in a plane parallel to the neutral axis of the heat exchanger. Summary of the invention

[0003] However, when multiple joints are arranged on the neutral axis of the heat exchanger, the heat exchanger does not contact the battery at the position where the multiple joints are arranged, so the cooling surface of the heat exchanger in contact with the battery tends to become smaller. Therefore, there is a problem that the cooling performance of the heat exchanger for the battery tends to be reduced.

[0004] Furthermore, when multiple joints are arranged on the planar cooling surface of the heat exchanger away from the neutral axis, the heat exchanger generates thermal strain due to the contraction stress of the multiple joints during cooling, so the cooling surface is easily deformed, and it is difficult for the cooling surface to contact the battery. Therefore, there is a problem that the cooling performance of the heat exchanger on the battery is easily reduced.

[0005] One aspect of the present disclosure is preferably to improve the cooling performance of a heat exchanger on a battery.

[0006] [Solution to the problem]

[0007] One scheme of the present disclosure is a heat exchanger that performs heat exchange with a battery mounted on an electric vehicle and includes a first plate member, a second plate member, and a plurality of joints. The first plate member is a plate-shaped member and is configured to be opposite to the battery. The second plate member is a plate-shaped member and is arranged to be opposite to the side of the first plate member opposite to the battery, and a flow path for a heat exchange medium to pass through is formed between the second plate member and the first plate member. The plurality of joints are locations where the first plate member and the second plate member are joined by welding. Moreover, the plurality of joints each have one of a plurality of welding lines, and the plurality of welding lines extend along the first direction and are arranged in a second direction orthogonal to the first direction to divide the flow path. The plurality of welding lines are respectively arranged on the first plate member side and the second plate member side relative to a neutral axis extending along the second direction in a cross section orthogonal to the first direction of the heat exchanger. Among the plurality of welding lines, a welding line located closer to the first plate member than the neutral axis is set as at least one first welding line, and a welding line located closer to the second plate member than the neutral axis is set as at least one second welding line. The total value of the shortest distances from the neutral axis to the at least one first welding line is substantially the same as the total value of the shortest distances from the neutral axis to the at least one second welding line.

[0008] In the above configuration, the deformation of the heat exchanger caused by the contraction stress of the first welding line when cooling is easily offset by the deformation of the heat exchanger caused by the contraction stress of the second welding line when cooling. Therefore, the influence caused by the thermal strain of the heat exchanger having the joint formed by welding can be suppressed. That is, the deformation of the first plate member can be suppressed, so that the first plate member can be easily contacted with the battery. Therefore, the cooling performance of the heat exchanger for the battery can be improved.

[0009] In one embodiment of the present disclosure, the number of at least one first welding line and the number of at least one second welding line may be the same. The shortest distance from the neutral axis to each of the at least one first welding line and the shortest distance from the neutral axis to each of the at least one second welding line may be the same.

[0010] In the above configuration, the deformation of the heat exchanger caused by the first welding line is easily offset by the deformation of the heat exchanger caused by the second welding line. Therefore, the influence of thermal strain caused by the heat exchanger having the joint formed by welding is suppressed. Therefore, the cooling performance of the heat exchanger for the battery can be improved.

[0011] In one embodiment of the present disclosure, the plurality of welding lines may be arranged line-symmetrically with respect to a center line in a cross section orthogonal to a first direction of the heat exchanger. The center line may be a line passing through the center of a second direction in a cross section orthogonal to the first direction of the heat exchanger and perpendicular to the neutral axis.

[0012] According to the above configuration, the influence of thermal strain of the heat exchanger can be suppressed at each location on both sides of the center line.

[0013] In one aspect of the present disclosure, the first direction may be a longitudinal direction of the heat exchanger.

[0014] The weld line extending in the longitudinal direction of the heat exchanger has a greater influence on the thermal strain of the heat exchanger than the weld line extending in the transverse direction of the heat exchanger. Therefore, according to the above-mentioned structure, it is easy to suppress the influence of the thermal strain of the heat exchanger.

[0015] In one embodiment of the present disclosure, the first plate member may have a contact portion. The contact portion is a portion in contact with the battery, and the contact portion is substantially parallel to the neutral axis and extends substantially in a planar shape in the first direction and the second direction. At least one first welding line may be disposed on the contact portion.

[0016] According to the above configuration, since the portion of the contact portion where the flow path is provided and the portion of the contact portion where the first welding line is provided are both in contact with the battery, the surface of the contact portion in contact with the battery and the surface area of ​​the contact portion that exchanges heat with the battery can be increased. Therefore, the cooling performance of the heat exchanger on the battery can be further improved.

[0017] In one aspect of the present disclosure, a plurality of weld lines may be formed by heat input to the joint portion. The sum of values ​​obtained by multiplying the shortest distance from the neutral axis to each of the at least one first weld lines by the amount of heat input when each of the at least one first weld lines is formed may be substantially the same as the sum of values ​​obtained by multiplying the shortest distance from the neutral axis to each of the at least one second weld lines by the amount of heat input when each of the at least one second weld lines is formed.

[0018] In the above configuration, in the evaluation of the influence of thermal strain on the heat exchanger, in addition to the shortest distance from the neutral axis to each weld line, the heat input amount when each weld line is formed is also taken into account. Thus, for example, even if the shrinkage stress of each weld line when cooling is different due to the different heat input amounts when each weld line is formed, the deformation of the heat exchanger caused by the first weld line can be easily offset by the deformation of the heat exchanger caused by the second weld line. Therefore, in a heat exchanger having a joint formed by heat input under different conditions during welding, the influence of thermal strain can also be suppressed. Therefore, the cooling performance of the heat exchanger for the battery can be improved.

[0019] In one aspect of the present disclosure, a method for manufacturing a heat exchanger may include: arranging the second plate member on the first plate member so that the first plate member and the second plate member abut against each other at a joint portion; and forming a plurality of weld lines by inputting heat to the joint portion, and joining the first plate member and the second plate member to each other. The sum of the values ​​obtained by multiplying the shortest distance from the neutral axis to each of the at least one first weld lines by the amount of heat input when each of the at least one first weld lines is formed may be substantially the same as the sum of the values ​​obtained by multiplying the shortest distance from the neutral axis to each of the at least one second weld lines by the amount of heat input when each of the at least one second weld lines is formed.

[0020] In the above configuration, in the evaluation of the influence of thermal strain on the heat exchanger, in addition to the shortest distance from the neutral axis to each weld line, the heat input amount when each weld line is formed is also taken into account. Thus, for example, even if the shrinkage stress of each weld line when cooling is different due to the different heat input amounts when each weld line is formed, the deformation of the heat exchanger caused by the first weld line can be easily offset by the deformation of the heat exchanger caused by the second weld line. Therefore, in a heat exchanger having a joint formed by heat input under different conditions during welding, the influence of thermal strain can also be suppressed. Therefore, the cooling performance of the heat exchanger for the battery can be improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 is a schematic perspective view showing a heat exchanger.

[0022] Figure 2 is a side view schematically showing the arrangement of the heat exchanger relative to the battery.

[0023] Figure 3 yes Figure 1 End view of the III-III section.

[0024] Figure 4 is a schematic top view showing a heat exchanger.

[0025] Figure 5 It is a schematic perspective view showing a heat exchanger according to a first modified example.

[0026] Figure 6 It is a side view schematically showing the arrangement of the heat exchanger relative to the battery according to the first modification.

[0027] Figure 7 It is a schematic plan view showing a heat exchanger according to a first modified example.

[0028] Figure 8This is an end view schematically showing the one-side structure of the heat exchanger according to the second modification with respect to the center line, in a cross section perpendicular to the longitudinal direction.

[0029] Fig. 9 This is an end view schematically showing the one-side structure of the heat exchanger according to the third modification with respect to the center line, in a cross section perpendicular to the longitudinal direction.

[0030] Fig.10 The figure schematically shows a heat exchange device arranged corresponding to the battery pack.

[0031] Fig.11 This is a diagram schematically showing a heat exchange device in which a plurality of heat exchangers are connected and integrated.

[0032] Fig.12 It is a diagram schematically showing the shape of a flow path of a heat exchanger according to a fourth modified example.

[0033] Fig.13 It is a diagram schematically showing the shape of the flow path of the heat exchanger according to the fifth modification.

[0034] Fig.14 is a flow chart showing a method for manufacturing a heat exchanger. DETAILED DESCRIPTION

[0035] Exemplary embodiments of the present disclosure are described below with reference to the accompanying drawings.

[0036] [1. Composition]

[0037] Figure 1 The heat exchanger 100 shown cools or heats the battery mounted on the electric vehicle by exchanging heat with the battery. An electric vehicle is a vehicle that uses the electric energy stored in the battery as all or part of the power of the vehicle. Electric vehicles include pure electric vehicles, plug-in hybrid vehicles, hybrid vehicles, fuel cell vehicles, etc. The heat exchanger 100 is constructed in a manner that a heat exchange medium such as cooling water flows inside. The heat exchanger 100 has an inlet 101 for allowing the heat exchange medium to flow into the heat exchanger 100, and an outlet 102 for allowing the heat exchange medium to be discharged from the heat exchanger 100.

[0038] In the present embodiment, the inlet 101 and the outlet 102 are provided on the first plate member 1 described below. Specifically, the inlet 101 is arranged at the first end S1 of the heat exchanger 100 in the horizontal direction S, and is arranged at the first end L1 of the heat exchanger 100 in the longitudinal direction L. The outlet 102 is arranged at the first end S1 of the heat exchanger 100 in the horizontal direction S, and is arranged at the second end L2 of the heat exchanger 100 in the longitudinal direction L. In addition, the positions of the inlet and the outlet in the heat exchanger can take various positions according to the shape of the flow path where the heat exchange medium flows.

[0039] like Figure 2 As shown, the heat exchanger 100 is arranged in a manner opposite to the contact surface 201 of the battery 200, and the battery 200 is located between the inlet 101 and the outlet 102. A heat conductive material 300 is arranged between the heat exchanger 100 and the battery 200. In addition, a heat conductive material may not be arranged between the heat exchanger and the battery. The frame 400 is provided in a manner surrounding the side extending orthogonally to the contact surface 201 of the battery 200, and the heat exchanger 100 is located closer to the inside than the frame 400. The surface of the heat exchanger 100 on the opposite side of the surface opposite to the battery 200 is covered by the lower shell 500. In addition, in Figure 2 In the figure, for the convenience of explanation, a part of the frame 400 is omitted.

[0040] When the heat exchanger 100 is mounted in an electric vehicle, the longitudinal direction L can be the front-to-back direction of the electric vehicle and the lateral direction S can be the left-right direction of the electric vehicle, or the longitudinal direction L can be the left-to-right direction of the electric vehicle and the lateral direction S can be the front-to-back direction of the electric vehicle.

[0041] like Figure 3 As shown, in the present embodiment, the heat exchanger 100 includes a first plate member 1 , a second plate member 2 , eight joints 3 , and six flow paths 4 .

[0042] <First Plate Member 1>

[0043] The first plate member 1 is a plate member in a substantially rectangular shape and faces the contact surface 201 of the battery 200. The first plate member 1 is made of a metal with high thermal conductivity, such as aluminum. Alternatively, the first plate member may be made of a metal with high corrosion resistance, such as stainless steel. The first plate member 1 has two contact portions 11 and three non-contact portions 12.

[0044] Each contact portion 11 is a portion that is in indirect or direct contact with the battery 200 of the first plate component 1. Each contact portion 11 is approximately parallel to the neutral axis N extending along the transverse direction S in a cross section (hereinafter referred to as a cross section) orthogonal to the longitudinal direction L of the heat exchanger 100, and extends in a roughly planar shape in the longitudinal direction L and the transverse direction S. The neutral axis refers to the intersection line of the neutral plane and the cross section, which is a surface in an object that does not produce compressive strain and tensile strain. On the neutral axis, even if a bending moment acts on the object, the tensile force is balanced with the compressive force, so that no stress intensity is generated on the cross section. The two contact portions 11 are located on the same plane and are arranged along the transverse direction S.

[0045] Each non-contact portion 12 extends along the longitudinal direction L of the heat exchanger 100. The three non-contact portions 12 are located on the same plane and are arranged along the transverse direction S. Among the three non-contact portions 12, one non-contact portion 12 is located at the first end S1 of the transverse direction S, one non-contact portion 12 is located at the second end S2 of the transverse direction S, and one non-contact portion 12 is located between two contact portions 11. The two contact portions 11 protrude from the three non-contact portions 12 toward a side (for example, above) where the battery 200 is arranged. That is, a step is formed between each non-contact portion 12 and each contact portion 11. In the present embodiment, the first plate member 1 has a plurality of through holes 13 at the non-contact portion 12 located between the two contact portions 11. The plurality of through holes 13 are arranged at intervals from each other in the longitudinal direction L. In addition, the first plate member may not have a plurality of through holes at the non-contact portion located between the two contact portions.

[0046] <Second Plate Part>

[0047] The second plate member 2 is a plate member in a substantially rectangular shape, and is arranged in a manner opposite to the side of the first plate member 1 opposite to the battery 200. For example, when the contact surface 201 of the battery 200 mounted on the electric vehicle extends in a substantially horizontal direction, the second plate member 2 is arranged below or above the first plate member 1. In addition, for example, when the contact surface 201 of the battery 200 mounted on the electric vehicle extends in a substantially vertical direction, the second plate member 2 is arranged to the left, right, front or rear of the first plate member 1. The second plate member 2 is similar to the first plate member 1, and is made of a metal with high thermal conductivity, such as aluminum. In addition, the second plate member can be made of a metal with high corrosion resistance, such as stainless steel. The second plate member 2 has five flat plate portions 21 and four convex portions 22.

[0048] Each flat plate portion 21 is a portion that does not abut against each contact portion 11 of the first plate member 1, and each flat plate portion 21 is approximately parallel to the neutral axis N, and extends in a substantially planar shape in the longitudinal direction L and the transverse direction S. The five flat plate portions 21 are located on the same plane and are arranged along the transverse direction S. Among the five flat plate portions 21, a flat plate portion 21 located at the first end S1 of the transverse direction S, a flat plate portion 21 located at the second end S2 of the transverse direction S, and a flat plate portion 21 located in the center of the second plate member 2 abut against each non-contact portion 12 of the first plate member 1 opposite to each flat plate portion 21. In the present embodiment, the second plate member 2 has a plurality of through holes 23 at the flat plate portion 21 located in the center of the transverse direction S. The plurality of through holes 23 are arranged at intervals from each other in the longitudinal direction L. Each through hole 23 of the second plate member 2 overlaps with each through hole 13 of the first plate member 1. In addition, the second plate member does not need to have a plurality of through holes in the flat plate portion located in the center in the transverse direction S.

[0049] Each convex portion 22 is a portion that contacts each contact portion 11 of the first plate member 1 and extends along the longitudinal direction L of the heat exchanger 100. The four convex portions 22 are arranged in the transverse direction S and are respectively located between two adjacent flat plate portions 21. The four convex portions 22 protrude from the five flat plate portions 21 toward the first plate member 1. That is, a step is formed between each convex portion 22 and each flat plate portion 21.

[0050] <Jointing section>

[0051] The eight joints 3 are where the first plate member 1 and the second plate member 2 are joined by welding, and the eight joints 3 extend along the longitudinal direction L of the heat exchanger 100. For welding, laser welding, arc welding, etc. are used, for example.

[0052] Each joint portion 3 is provided at a position where each contact portion 11 of the first plate member 1 abuts each convex portion 22 of the second plate member 2, and at a position where each non-contact portion 12 of the first plate member 1 abuts each flat plate portion 21 of the second plate member 2. The two contact portions 11 of the first plate member 1 and the five flat plate portions 21 of the second plate member 2 do not abut, but are spaced apart from each other. Thus, six flow paths 4 for the heat exchange medium to pass through are formed between the first plate member 1 and the second plate member 2.

[0053] like Figure 3 and Figure 4As shown, each joint 3 has a welding line. In the present embodiment, the heat exchanger 100 has eight welding lines 31a to 31h. The eight welding lines 31a to 31h are parallel to the neutral plane along the neutral axis N, and extend straight along the longitudinal direction L, and the eight welding lines 31a to 31h are arranged in the transverse direction S to divide the first plate member 1 and the second plate member 2 into the above-mentioned six flow paths 4. With respect to the neutral axis N, a part of the eight welding lines 31a to 31h is arranged on the first plate member 1 side, and the rest is arranged on the second plate member 2 side. In the following description, among the eight welding lines 31a to 31h, the welding lines located closer to the first plate member 1 than the neutral axis N are also referred to as first welding lines 31b, 31c, 31f, and 31g, and the welding lines located closer to the second plate member 2 than the neutral axis N are also referred to as second welding lines 31a, 31d, 31e, and 31h.

[0054] The eight welding lines 31a to 31h are arranged line-symmetrically with respect to the center line A in the cross section of the heat exchanger 100. The center line A is a line that passes through the center of the cross section of the heat exchanger 100 in the longitudinal direction S and is perpendicular to the neutral axis N.

[0055] Specifically, two first welding lines 31b and 31c are arranged at the contact portion 11 on the first end S1 side of the first plate member 1, and two first welding lines 31f and 31g are arranged at the contact portion 11 on the second end S2 side of the first plate member 1. The second welding line 31a is arranged at the non-contact portion 12 located at the first end S1 of the first plate member 1, and the second welding line 31h is arranged at the non-contact portion 12 located at the second end S2 of the first plate member 1. The second welding line 31d is arranged at a position closer to the first end S1 side than each through hole 13 and 23 in the non-contact portion 12 located at the center in the lateral direction S of the first plate member 1, and the second welding line 31e is arranged at a position closer to the second end S2 side than each through hole 13 and 23 in the non-contact portion 12.

[0056] Moreover, the sum of the shortest distances LA1, LA2, LA3, and LA4 from the neutral axis N to the first weld lines 31b, 31c, 31f, and 31g is substantially the same as the sum of the shortest distances LB1, LB2, LB3, and LB4 from the neutral axis N to the second weld lines 31a, 31d, 31e, and 31h. In the present embodiment, the number of the plurality of first weld lines 31b, 31c, 31f, and 31g is the same as the number of the plurality of second weld lines 31a, 31d, 31e, and 31h, which is four. In addition, the shortest distances LA1, LA2, LA3, and LA4 are the same as the shortest distances LB1, LB2, LB3, and LB4, which are, for example, 1.0 mm. That is, as shown in the present embodiment, when a plurality of first welding lines 31b, 31c, 31f, 31g and a plurality of second welding lines 31a, 31d, 31e, 31h, etc. are distributed on both sides of the neutral axis N, (the number of first welding lines × the shortest distance from the neutral axis N to the first welding line) = (the number of second welding lines × the shortest distance from the neutral axis N to the second welding line) holds.

[0057] To form a heat exchange medium along Figure 4 The ends of the respective weld lines 31 a to 31 h in the longitudinal direction L are also connected by weld lines extending along the transverse direction S in the manner of the six flow paths 4 flowing from the inlet 101 to the outlet 102 as indicated by the arrows.

[0058] <Method for manufacturing heat exchanger>

[0059] Next, use Fig.14 The following describes a method for manufacturing the heat exchanger 100. The method for manufacturing the heat exchanger 100 includes a pressing step S10, an arranging step S20, and a joining step S30.

[0060] (Pressing process)

[0061] First, a flat plate blank material is punched to form a first plate member 1 and a second plate member 2 of a predetermined shape. Specifically, the first plate member 1 is punched to form two contact portions 11 and three non-contact portions 12. Furthermore, the second plate member 2 is punched to form five flat plate portions 21 and four convex portions 22.

[0062] (Configuration process)

[0063] Next, the second plate member 2 is placed on the first plate member 1 in such a manner that the first plate member 1 and the second plate member 2 abut against each other at each joint portion 3 (see Figure 3Specifically, in each joint portion 3, the first plate member 1 and the second plate member 2 are arranged to overlap each other so that the two contact portions 11 abut against the four convex portions 22 and the three non-contact portions 12 abut against the three flat plate portions 21 facing thereto.

[0064] (Joining process)

[0065] Next, eight welding lines 31a to 31h are formed by heat input to each joint portion 3, thereby joining the first plate member 1 and the second plate member 2. Specifically, each joint portion 3 is irradiated with, for example, laser light along the longitudinal direction L. As described above, eight welding lines 31a to 31h are formed in such a manner that each first welding line 31b, 31c, 31f, 31g and each second welding line 31a, 31d, 31e, 31h are arranged on both sides of the neutral axis N (see FIG. 2 ). Figure 3 ). Thus, the heat exchanger 100 can be obtained.

[0066] Each welding line 31a to 31h is formed by heat input to each joint part 3 using laser light or the like, thereby causing melting in the first plate member 1 and the second plate member 2. In the present embodiment, in the joining step S30, heat input to each joint part 3 is performed under certain conditions. That is, the heat input amount when forming each welding line 31a to 31h is substantially the same. The heat input amount is calculated by (power during welding ÷ welding speed × welding length).

[0067] [2. Effect]

[0068] According to the embodiments described in detail above, the following effects can be obtained.

[0069] (2a) In the present embodiment, the plurality of first welding lines 31b, 31c, 31f, 31g and the plurality of second welding lines 31a, 31d, 31e, 31h are equally arranged on both sides of the neutral axis N. Thus, the deformation of the heat exchanger 100 caused by the contraction stress of each of the first welding lines 31b, 31c, 31f, 31g during cooling is easily offset by the deformation of the heat exchanger 100 caused by the contraction stress of each of the second welding lines 31a, 31d, 31e, 31h during cooling. Therefore, the influence of the thermal strain of the heat exchanger 100 having eight joints 3 can be suppressed. That is, the deformation of the first plate member 1 can be suppressed, so that the two contact portions 11 of the first plate member 1 can be easily brought into contact with the battery 200 indirectly or directly. In other words, the surface of each contact portion 11 that faces the battery 200 and exchanges heat with the battery 200 is easily maintained in a flat state. Therefore, the cooling performance of the heat exchanger 100 for the battery 200 can be improved. Furthermore, since the deformation of the first plate member 1 can be suppressed, the assemblability of the heat exchanger 100 for the battery 200 is also improved.

[0070] (2b) In the present embodiment, two first welding lines 31b and 31c are arranged at the contact portion 11 on the first end S1 side of the first plate member 1, and two first welding lines 31f and 31g are arranged at the contact portion 11 on the second end S2 side of the first plate member 1. Thus, the portion of each contact portion 11 where each flow path 4 is provided and the portion of each contact portion 11 where each first welding line 31b, 31c, 31f, 31g is provided are all in direct or indirect contact with the battery 200. Therefore, it is possible to ensure that the surface area of ​​each contact portion 11 that is in direct or indirect contact with the battery 200 and performs heat exchange with the battery 200 is large. Therefore, the cooling performance of the heat exchanger 100 on the battery 200 can be further improved.

[0071] (2c) In this embodiment, the eight welding lines 31a to 31h are arranged line-symmetrically with respect to the center line A in the cross section of the heat exchanger 100. Therefore, the influence of thermal strain of the heat exchanger 100 can be suppressed at each location on both sides of the center line A.

[0072] (2d) In the present embodiment, the eight welding lines 31a to 31h extend along the longitudinal direction L of the heat exchanger 100. The welding lines extending along the longitudinal direction L of the heat exchanger 100 have a greater influence on the thermal strain of the heat exchanger 100 than the welding lines extending along the transverse direction S of the heat exchanger 100. Therefore, according to the structure of the heat exchanger 100 of the present embodiment, it is easy to suppress the influence caused by the thermal strain of the heat exchanger 100.

[0073] In addition, in the present embodiment, the longitudinal direction L corresponds to an example of the first direction, and the transverse direction S corresponds to an example of the second direction.

[0074] [3. Other embodiments]

[0075] As mentioned above, although embodiment of this disclosure is described, this disclosure is not limited to the said embodiment, Various forms can be adopted.

[0076] (3a) In the above embodiment, the inlet 101 and the outlet 102 of the heat exchange medium are arranged on the first plate member 1, but the arrangement of the inlet and the outlet is not limited to this. Figure 5 to Figure 7 As shown, the inlet 101a and the outlet 102a included in the heat exchanger 100a of the first modified example may be provided at a portion extending from the first end S1 in the longitudinal direction S of the first plate member 1a.

[0077] In this case, if Figure 6As shown, the heat exchanger 100a is arranged so as to face the contact surface 201 of the battery 200 and so as not to overlap the battery 200 with the inlet 101a and the outlet 102a in the lateral direction S. The heat conductive material 300 may or may not be arranged between the heat exchanger 100a and the battery 200. The frame 400 is arranged so as to surround the side of the battery 200, and the inlet 101a and the outlet 102a are located closer to the outside than the frame 400. Figure 6 In the figure, for the sake of convenience, a part of the frame 400 is omitted. The heat exchanger 100a of the first modified example can also serve as a lower shell. Therefore, the surface of the heat exchanger 100a located on the opposite side of the surface facing the battery 200 is different from the heat exchanger 100 of the above embodiment and may not be covered by the lower shell.

[0078] (3b) In the above embodiment, the heat exchanger 100 is exemplified in which six flow paths 4 are formed by eight joints 3 having four first welding lines 31b, 31c, 31f, and 31g and four second welding lines 31a, 31d, 31e, and 31h equally arranged on both sides of the neutral axis N. However, the structure of the heat exchanger is not limited thereto, and the number of flow paths, that is, the number of welding lines, is not limited.

[0079] For example, Figure 8 The heat exchanger 100b of the second modified example shown may be a structure in which eight flow paths 4b are formed by ten joints 3b. Specifically, the first plate member 1b may have two contact portions 11b and three non-contact portions 12b, and the second plate member 2b may have seven flat portions 21b and six convex portions 22b. Figure 8 In the figure, for ease of explanation, only the structure of the half portion (hereinafter referred to as the first portion) of the heat exchanger 100b located on the first end S1 side is shown with the center line A as the center, but the heat exchanger 100b is a linearly symmetrical structure relative to the center line A in the cross section of the heat exchanger 100b.

[0080] In the first part of the heat exchanger 100b, each joint 3b has a welding line. The first part of the heat exchanger 100b has five welding lines 32a to 32e. The three first welding lines 32b, 32c, and 32d are arranged at the contact portion 11b on the first end S1 side of the first plate member 1b. In addition, the second welding line 32a is arranged at the non-contact portion 12b of the first end S1 of the first plate member 1b, and the second welding line 32e is arranged in the non-contact portion 12b located in the center of the horizontal direction S of the first plate member 1b at a position closer to the first end S1 side than each through hole 13, 23.

[0081] Thus, the portion of each contact portion 11b where each flow path 4b is provided and the portion of each contact portion 11b where each first welding line 32b, 32c, 32d is provided are in direct or indirect contact with the battery 200. Therefore, the surface area of ​​each contact portion 11b that is in direct or indirect contact with the battery 200 and performs heat exchange with the battery 200 can be ensured to be large.

[0082] In addition, in the first part of the heat exchanger 100b, the number of the plurality of first welding lines 32b, 32c, and 32d is three, and the number of the plurality of second welding lines 32a and 32e is two. The amount of deformation due to thermal strain of the joint portion of the heat exchanger changes depending on the distance between the neutral axis and the welding lines of the joint portion. Therefore, in the case of a configuration in which the number of the plurality of first welding lines 32b, 32c, and 32d is different from the number of the plurality of second welding lines 32a and 32e, as in the heat exchanger 100b, the shortest distance from the neutral axis N to the first welding line and the shortest distance from the neutral axis N to the second welding line are set to different values. In the configuration of the heat exchanger 100b, the shortest distances LC1, LC2, and LC3 from the neutral axis N to the first weld lines 32b, 32c, and 32d are set to, for example, 0.8 mm, and the shortest distances LD1 and LD2 from the neutral axis N to the second weld lines 32a and 32e are set to, for example, 1.2 mm. As a result, the total value of the shortest distances LC1, LC2, and LC3 from the neutral axis N to the first weld lines 32b, 32c, and 32d is substantially the same as the total value of the shortest distances LD1 and LD2 from the neutral axis N to the second weld lines 32a and 32e.

[0083] Thus, the deformation of the heat exchanger 100b caused by the contraction stress of each of the first welding lines 32b, 32c, and 32d during cooling is easily offset by the deformation of the heat exchanger 100b caused by the contraction stress of each of the second welding lines 32a and 32e during cooling. Therefore, the influence of the thermal strain of the heat exchanger 100b can be suppressed. That is, the deformation of the first plate member 1b can be suppressed, so that the two contact portions 11b of the first plate member 1b are easily in direct or indirect contact with the battery 200. Therefore, the cooling performance of the heat exchanger 100b for the battery 200 can be improved.

[0084] In addition, for example Fig. 9 The heat exchanger 100c of the third modified example shown may be a structure in which ten flow paths 4c are formed by twelve joints 3c. Specifically, the first plate member 1c may have two contact portions 11c and three non-contact portions 12c, and the second plate member 2c may have nine flat portions 21c and eight convex portions 22c. Fig. 9In the figure, for ease of explanation, only the structure of the half portion (hereinafter referred to as the second portion) of the heat exchanger 100c located on the first end S1 side is shown with the center line A as the center, but the heat exchanger 100c is a linearly symmetrical structure relative to the center line A in the cross section of the heat exchanger 100c.

[0085] In the second part of the heat exchanger 100c, each joint 3c has a welding line. The second part of the heat exchanger 100c has six welding lines 33a to 33f. Four first welding lines 33b, 33c, 33d, and 33e are arranged at the contact portion 11c on the first end S1 side of the first plate member 1c. In addition, the second welding line 33a is arranged at the non-contact portion 12c of the first end S1 of the first plate member 1c. The second welding line 33f is arranged at a position closer to the first end S1 side than each through hole 13, 23 in the non-contact portion 12c located in the center of the horizontal direction S of the first plate member 1c.

[0086] Thus, the portion of each contact portion 11c where each flow path 4c is provided and the portion of each contact portion 11c where each first welding line 33b, 33c, 33d, 33e is provided are in direct or indirect contact with the battery 200. Therefore, the surface area of ​​each contact portion 11c that is in direct or indirect contact with the battery 200 and performs heat exchange with the battery 200 can be ensured to be large.

[0087] In the second portion of the heat exchanger 100c, the number of the plurality of first welding lines 33b, 33c, 33d, 33e is four, and the number of the plurality of second welding lines 33a, 33f is two. In the heat exchanger 100c, the number of the plurality of first welding lines 33b, 33c, 33d, 33e is different from the number of the plurality of second welding lines 33a, 33f, as in the heat exchanger 100b. Therefore, in the configuration of the heat exchanger 100c, the shortest distances LE1, LE2, LE3, LE4 from the neutral axis N to the first welding lines 33b, 33c, 33d, 33e are set to, for example, 0.7 mm, and the shortest distances LF1, LF2 from the neutral axis N to the second welding lines 33a, 33f are set to, for example, 1.4 mm. As a result, the total value of the shortest distances LE1, LE2, LE3, LE4 from the neutral axis N to the first weld lines 33b, 33c, 33d, 33e is substantially the same as the total value of the shortest distances LF1, LF2 from the neutral axis N to the second weld lines 33a, 33f.

[0088] Thus, the deformation of the heat exchanger 100c caused by the contraction stress of each of the first welding lines 33b, 33c, 33d, and 33e during cooling is easily offset by the deformation of the heat exchanger 100c caused by the contraction stress of each of the second welding lines 33a and 33f during cooling. Therefore, the influence of the thermal strain of the heat exchanger 100c can be suppressed. That is, the deformation of the first plate member 1c can be suppressed, so that the two contact portions 11c of the first plate member 1c are easily in direct or indirect contact with the battery 200. Therefore, the cooling performance of the heat exchanger 100c for the battery 200 can be improved.

[0089] (3c) In the above-mentioned embodiment and the first to third modified examples, the shortest distances from the neutral axis N to the first weld lines are fixed, and the shortest distances from the neutral axis N to the second weld lines are fixed. However, for example, if the total value of the shortest distances from the neutral axis N to the first weld lines is substantially the same as the total value of the shortest distances from the neutral axis N to the second weld lines, the values ​​of the shortest distances may not be fixed.

[0090] (3d) In the above-described embodiment and the first to third modified examples, the plurality of weld lines are arranged line-symmetrically with respect to the center line A in the cross section of the heat exchanger. However, for example, if the total value of the shortest distances from the neutral axis N to the first weld lines is substantially the same as the total value of the shortest distances from the neutral axis N to the second weld lines, the weld lines may not be arranged line-symmetrically with respect to the center line A.

[0091] (3e) In the above-described embodiment and the first to third modified examples, the first welding line and the second welding line extend along the longitudinal direction L of the heat exchanger 100b to form six flow paths 4. However, for example, the first welding line and the second welding line may extend along the transverse direction S of the heat exchanger to form a plurality of flow paths through which the heat exchange medium flows.

[0092] (3f) In the above-described embodiment and the first to third modified examples, the first welding line is disposed at the contact portion 11 of the first plate member 1 . However, the first welding line may not be disposed at the contact portion.

[0093] (3g) In the above embodiment, the heat exchanger 100 is exemplified as having a size corresponding to the battery 200. However, for example, the heat exchanger 100 may be configured as a combination of a plurality of batteries 200 and arranged in the annular frame 600. Fig.10 In the embodiment corresponding to the battery pack 220 shown in FIG. 1 , the heat exchangers 100 are arranged in a row in the horizontal direction S and a plurality of heat exchangers 100 are connected (see FIG. 1 ). Fig.11 The heat exchange device 110, which is a combination of a plurality of heat exchangers 100, is arranged to face the battery pack 220. Fig.11In the example shown, when the heat exchanger 100 is mounted on the electric vehicle, the longitudinal direction L of the heat exchanger 100 is the left-right direction of the electric vehicle, and the transverse direction S of the heat exchanger 100 is the front-back direction of the electric vehicle. In addition, when the heat exchanger 100 is mounted on the electric vehicle, the longitudinal direction L of the heat exchanger 100 may be the front-back direction of the electric vehicle, and the transverse direction S of the heat exchanger 100 may be the left-right direction of the electric vehicle.

[0094] (3h) In the above embodiment, the heat exchange medium is exemplified as follows: Figure 4 The arrows shown in FIG. 4 are the shape of the flow path 4 from the inlet 101 to the outlet 102, but the shape of the flow path is not limited thereto. Fig.12 As shown, the heat exchanger 100d of the fourth modification may have a shape of a flow path 4d as indicated by an arrow in which the heat exchange medium flows from the inlet 101d to the outlet 102d. Fig.13 As shown in FIG. 1 , a heat exchanger 100e according to the fifth modification may have a shape of a flow path 4e as indicated by an arrow indicating that a heat exchange medium flows from an inlet 101e to an outlet 102e.

[0095] (3i) In the above embodiment, in the joining step S30, heat input to each joining portion 3 is performed under certain conditions. That is, in the above embodiment, the heat input amount when each welding line 31a to 31h is formed is substantially the same. However, for example, in the joining step S30, heat input to each joining portion may be performed under different conditions. That is, the heat input amount when each welding line is formed may be different.

[0096] Here, if the heat input amount changes, the contraction stress of the weld line when it is cooled changes. Therefore, for example, in addition to the shortest distance from the neutral axis N to each weld line, the heat input amount when each weld line is formed can also be adopted to evaluate the influence of the thermal strain of the heat exchanger. For example, in a structure where the heat exchanger has a plurality of weld lines, when the heat input amount is adopted, the total value of the values ​​obtained by multiplying the shortest distance from the neutral axis N to each first weld line by the heat input amount when each first weld line is formed can be substantially the same as the total value of the values ​​obtained by multiplying the shortest distance from the neutral axis N to each second weld line by the heat input amount when each second weld line is formed.

[0097] Specifically, as shown in the above embodiment, taking the case where the heat exchanger 100 has eight welding lines 31a to 31h as an example, it can be ((shortest distance LA1×heat input amount QA1)+(shortest distance LA2×heat input amount QA2)+(shortest distance LA3×heat input amount QA3)+(shortest distance LA4×heat input amount QA4))=((shortest distance LB1×heat input amount QB1)+(shortest distance LB2×heat input amount QB2)+(shortest distance LB3×heat input amount QB3)+(shortest distance LB4×heat input amount QB4)). Each heat input amount QA1 to QA4 is the heat input amount when forming each of the first welding lines 31b, 31c, 31f, and 31g. Moreover, each heat input amount QB1 to QB4 is the heat input amount when forming each of the second welding lines 31a, 31d, 31e, and 31h.

[0098] Thus, since the heat input amount is different, even if the shrinkage stress of each welding line when cooling is different, the deformation of the heat exchanger caused by the shrinkage stress of each first welding line when cooling is easily offset by the deformation of the heat exchanger caused by the shrinkage stress of each second welding line when cooling. Therefore, considering the shape, thickness, size, etc. of the heat exchanger, even in a heat exchanger having a joint formed by heat input under different conditions during welding, the influence of thermal strain can be suppressed. That is, by adopting the heat input amount, it is easy to expand the design range of the heat exchanger with improved cooling performance. In addition, in the joining step S30, even if the heat input to the joint is performed under certain conditions, the heat input amount when each welding line is formed is substantially the same. In the evaluation of the influence of thermal strain on the heat exchanger, in addition to the shortest distance from the neutral axis to each welding line, the heat input amount when each welding line is formed can also be adopted.

[0099] (3j) The functions of one component in the above-mentioned embodiment may be dispersed among multiple components, or the functions of multiple components may be integrated into one component. In addition, a part of the components of the above-mentioned embodiment may be omitted. At least a part of the components of the above-mentioned embodiment may be added to the components of the above-mentioned other embodiments, or at least a part of the components of the above-mentioned embodiment may be replaced with the components of the above-mentioned other embodiments.

[0100] [4. Technical ideas disclosed in this specification]

[0101] [Project 1]

[0102] A heat exchanger that performs heat exchange with a battery mounted on an electric vehicle, the heat exchanger being characterized by comprising:

[0103] a first plate member, the first plate member being a plate-shaped member and configured to face the battery;

[0104] a second plate member, the second plate member being a plate-shaped member and arranged to face the side of the first plate member opposite to the side facing the battery, and forming a flow path for a heat exchange medium to pass therethrough between the second plate member and the first plate member; and

[0105] a plurality of joints, wherein the plurality of joints are locations where the first plate member and the second plate member are joined by welding;

[0106] The plurality of joints each have one of a plurality of welding lines, the plurality of welding lines extending along a first direction and arranged in a second direction orthogonal to the first direction to divide the flow path,

[0107] The plurality of welding lines are arranged on the first plate member side and the second plate member side, respectively, with respect to a neutral axis extending along the second direction in a cross section perpendicular to the first direction of the heat exchanger.

[0108] Among the plurality of welding lines, a welding line located closer to the first plate member than the neutral axis is set as at least one first welding line, and a welding line located closer to the second plate member than the neutral axis is set as at least one second welding line,

[0109] A total value of the shortest distances from the neutral axis to the at least one first welding line is substantially the same as a total value of the shortest distances from the neutral axis to the at least one second welding line.

[0110] [Project 2]

[0111] The heat exchanger according to item 1 is characterized in that

[0112] The number of the at least one first welding line is the same as the number of the at least one second welding line,

[0113] The shortest distance from the neutral axis to each of the at least one first welding line is the same as the shortest distance from the neutral axis to each of the at least one second welding line.

[0114] [Item 3]

[0115] The heat exchanger according to item 1 or 2, characterized in that

[0116] The plurality of welding lines are arranged in line symmetry with respect to the center line in the cross section,

[0117] The center line is a line that passes through the center of the second direction in the cross section and is perpendicular to the neutral axis.

[0118] [Item 4]

[0119] The heat exchanger according to any one of items 1 to 3, characterized in that

[0120] The first direction is the longitudinal direction of the heat exchanger.

[0121] [Item 5]

[0122] The heat exchanger according to any one of items 1 to 4, characterized in that

[0123] The first plate member has a contact portion, the contact portion is a portion in contact with the battery, and the contact portion is substantially parallel to the neutral axis and extends in a substantially planar shape in the first direction and the second direction.

[0124] The at least one first welding line is disposed at the contact portion.

[0125] [Item 6]

[0126] The heat exchanger according to any one of items 1 to 5, characterized in that

[0127] forming the plurality of weld lines by heat input to the joint,

[0128] A total value of values ​​obtained by multiplying the shortest distance from the neutral axis to each of the at least one first weld lines by the amount of heat input when each of the at least one first weld lines is formed is substantially the same as a total value of values ​​obtained by multiplying the shortest distance from the neutral axis to each of the at least one second weld lines by the amount of heat input when each of the at least one second weld lines is formed.

[0129] [Item 7]

[0130] A method for manufacturing a heat exchanger is a method for manufacturing a heat exchanger according to any one of items 1 to 5, wherein the method for manufacturing a heat exchanger is characterized by comprising:

[0131] placing the second plate member on the first plate member so as to overlap the first plate member and the second plate member abut against each other at the joint portion; and

[0132] forming the plurality of welding lines by inputting heat to the joint portion, and joining the first plate member and the second plate member to each other;

[0133] A total value of values ​​obtained by multiplying the shortest distance from the neutral axis to each of the at least one first weld lines by the amount of heat input when each of the at least one first weld lines is formed is substantially the same as a total value of values ​​obtained by multiplying the shortest distance from the neutral axis to each of the at least one second weld lines by the amount of heat input when each of the at least one second weld lines is formed.

Claims

1. A heat exchanger for performing heat exchange with a battery mounted on an electric vehicle, the heat exchanger comprising: a first plate member, the first plate member being a plate-shaped member and configured to face the battery; a second plate member, the second plate member being a plate-shaped member and arranged to face the side of the first plate member opposite to the side facing the battery, and forming a flow path for a heat exchange medium to pass therethrough between the second plate member and the first plate member; and a plurality of joints, wherein the plurality of joints are locations where the first plate member and the second plate member are joined by welding; The plurality of joints each have one of a plurality of welding lines, the plurality of welding lines extending along a first direction and arranged in a second direction orthogonal to the first direction to divide the flow path, The plurality of welding lines are arranged on the first plate member side and the second plate member side, respectively, with respect to a neutral axis extending along the second direction in a cross section perpendicular to the first direction of the heat exchanger. Among the plurality of welding lines, a welding line located closer to the first plate member than the neutral axis is set as at least one first welding line, and a welding line located closer to the second plate member than the neutral axis is set as at least one second welding line, A total value of the shortest distances from the neutral axis to the at least one first welding line is substantially the same as a total value of the shortest distances from the neutral axis to the at least one second welding line.

2. The heat exchanger according to claim 1, characterized in that The number of the at least one first welding line is the same as the number of the at least one second welding line, The shortest distance from the neutral axis to each of the at least one first welding line is the same as the shortest distance from the neutral axis to each of the at least one second welding line.

3. The heat exchanger according to claim 1 or 2, characterized in that: The plurality of welding lines are arranged in line symmetry with respect to the center line in the cross section, The center line is a line that passes through the center of the second direction in the cross section and is perpendicular to the neutral axis.

4. The heat exchanger according to claim 1 or 2, characterized in that: The first direction is the longitudinal direction of the heat exchanger.

5. The heat exchanger according to claim 1 or 2, characterized in that: The first plate member has a contact portion, the contact portion is a portion in contact with the battery, and the contact portion is substantially parallel to the neutral axis and extends in a substantially planar shape in the first direction and the second direction. The at least one first welding line is disposed at the contact portion.

6. The heat exchanger according to claim 1 or 2, characterized in that: forming the plurality of weld lines by heat input to the joint, A total value of values ​​obtained by multiplying the shortest distance from the neutral axis to each of the at least one first weld lines by the amount of heat input when each of the at least one first weld lines is formed is substantially the same as a total value of values ​​obtained by multiplying the shortest distance from the neutral axis to each of the at least one second weld lines by the amount of heat input when each of the at least one second weld lines is formed.

7. A method for manufacturing a heat exchanger, comprising: The second plate member is arranged to overlap the first plate member so that the first plate member and the second plate member abut against each other at the joint portion; as well as forming the plurality of welding lines by inputting heat to the joint portion, and joining the first plate member and the second plate member to each other; A total value of values ​​obtained by multiplying the shortest distance from the neutral axis to each of the at least one first weld lines by the amount of heat input when each of the at least one first weld lines is formed is substantially the same as a total value of values ​​obtained by multiplying the shortest distance from the neutral axis to each of the at least one second weld lines by the amount of heat input when each of the at least one second weld lines is formed.

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