heat exchanger
The heat exchanger design for electric vehicles addresses complex manufacturing by positioning welded and heat input sections to straddle the neutral axis, offsetting bending forces and simplifying the process while maintaining thermal strain balance.
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- FUTABA IND CO LTD
- Filing Date
- 2024-11-08
- Publication Date
- 2026-05-20
AI Technical Summary
The existing heat exchangers for electric vehicles require complex bending processes to suppress distortion due to laser welding, complicating the manufacturing process.
A heat exchanger design that includes a first plate member facing the battery, a second plate member forming a flow path, welded portions, and heat input portions positioned to straddle the neutral axis, offsetting bending forces through thermal strain balance.
Suppresses bending deformation in the heat exchanger with a simpler process by generating thermal strain opposite to the welded joint, maintaining thermal strain balance and reducing unwanted deformation.
Smart Images
Figure 2026083801000001_ABST
Abstract
Description
Technical Field
[0001] The present disclosure relates to a heat exchanger that performs heat exchange with a battery mounted on an electric vehicle.
Background Art
[0002] Patent Document 1 below discloses a technique for suppressing distortion due to laser welding by forming a bent portion or a protruding portion by processing for bending a material and improving rigidity in a heat exchanger formed by laser welding.
Prior Art Document
Patent Document
[0003]
Patent Document 1
Summary of the Invention
Problems to be Solved by the Invention
[0004] However, the heat exchanger of Patent Document 1 above has a problem that processing for bending a material is required and the manufacturing process of the heat exchanger is complicated. One aspect of the present disclosure is to suppress distortion due to laser welding in a simple process in a heat exchanger that performs heat exchange with a battery.
Means for Solving the Problems
[0005] One aspect of the present disclosure is a heat exchanger configured to perform heat exchange with a battery mounted on an electric vehicle. The heat exchanger includes a first plate member, a second plate member, at least one welding portion, and at least one heat input portion. The first plate member is a plate-shaped member configured to face the battery. The second plate member is disposed to face the surface of the first plate member opposite to the battery, and is a plate-shaped member that forms a flow path through which a heat exchange medium passes between the first plate member.
[0006] The welded portion is the area where the first plate member and the second plate member are joined by welding, and which extends along the first direction. The heat input portion is the area in at least one of the first plate member and the second plate member that is heated without being joined to the other member. The welded portion and the heat input portion are located so as to straddle the neutral axis of the heat exchanger in a cross section perpendicular to the first direction.
[0007] With this configuration, the welded joint experiences bending forces due to thermal contraction. However, since the heat input section of the heat exchanger is formed on the opposite side of the welded joint, across the neutral axis, it can generate a bending force in the opposite direction to the bending force caused by the welded joint. In other words, by generating thermal strain on the side opposite to the side where the effect of thermal strain is greater than that of the neutral axis, the balance of thermal strain can be maintained. Therefore, with this configuration, the bending force caused by the welded joint can be offset by the bending force in the opposite direction from the heat input section, thus suppressing bending deformation in the heat exchanger with a simpler process compared to bending.
[0008] In one aspect of this disclosure, the heat input portion may be a portion formed to extend along a first direction. With such a configuration, since the heat input portion and the weld portion are arranged parallel to each other, the bending force can be suppressed along the direction in which the portion where the bending force is generated extends (i.e., the first direction).
[0009] In one aspect of this disclosure, the midpoint of the heat input portion and the midpoint of the weld portion may be at the same position in the first direction. With this configuration, since the positions of the midpoints are aligned in the first direction, the bending force near the midpoint in the first direction can be effectively suppressed.
[0010] In one aspect of this disclosure, the heat exchanger may have multiple heat input sections, with at least one heat input section. In this configuration, when the direction in which the neutral axis extends in the cross-section is defined as the second direction, the multiple heat input sections may be arranged symmetrically with respect to the center of the second direction in the heat exchanger. With such a configuration, the bending force in the heat input sections is generated uniformly with respect to the center of the second direction, making it less likely for unwanted bending forces in the second direction to be generated.
[0011] In one aspect of this disclosure, the weld may consist of multiple welds, with at least one weld being provided. Furthermore, the heat input may consist of multiple heat inputs, with at least one heat input being provided. Additionally, the product of the distance from each weld to the neutral axis and the heat required to form the weld is calculated for each weld, and the sum of these products is defined as the welding heat. Similarly, the product of the distance from each heat input to the neutral axis and the heat required to form the heat input is calculated for each heat input, and the sum of these products is defined as the heat input. In such a configuration, the heat input may be configured to coincide with the welding heat.
[0012] With this configuration, the bending forces across the neutral axis can be made approximately the same. Therefore, the bending deformation of the heat exchanger can be suppressed. Note that "approximately the same" may include "nearly the same". [Brief explanation of the drawing]
[0013] [Figure 1] This is a schematic perspective view showing a heat exchanger. [Figure 2] This is a central cross-sectional view of Figure 1. [Figure 3] This is a schematic perspective view showing the second plate member. [Figure 4] Figure 4A is a schematic cross-sectional view showing the heat exchanger of the first modified example, and Figure 4B is a schematic cross-sectional view showing the heat exchanger of the second modified example. [Figure 5] Figure 5A is a schematic cross-sectional view showing the heat exchanger of the third modified example, Figure 5B is a schematic cross-sectional view showing the heat exchanger of the fourth modified example, and Figure 5C is a schematic cross-sectional view showing the heat exchanger of the fifth modified example. [Modes for carrying out the invention]
[0014] Hereinafter, exemplary embodiments of the present disclosure will be described with reference to the drawings. [1. Embodiments] [1-1. Structure] The heat exchanger 100 shown in Figure 1 cools or heats a battery 200 (see, for example, Figure 2) mounted on an electric vehicle by exchanging heat with the battery. An electric vehicle is an automobile that runs using the electrical energy stored in the battery 200 as all or part of its power. Electric vehicles include electric vehicles, plug-in hybrid vehicles, hybrid vehicles, fuel cell vehicles, etc. The heat exchanger 100 is configured so that a heat exchange medium such as cooling water flows through its interior.
[0015] The heat exchanger 100 comprises a first plate member 10, a second plate member 20, one welded joint 31, four welded joints 32, and two heat input sections 33. The heat exchanger 100 may also include an inlet 121 through which the heat exchange medium flows into the heat exchanger 100, and an outlet 122 through which the heat exchange medium is discharged from the heat exchanger 100.
[0016] In this embodiment, the inlet 121 and outlet 122 are provided on the first plate member 10. Specifically, the inlet 121 is located at the first end in the first direction L, which is the longitudinal direction of the heat exchanger 100, and approximately in the center of the second direction S, which is the short direction of the heat exchanger 100. The outlet 122 is located at the second end in the first direction L of the heat exchanger 100, and approximately in the center of the second direction S. The second end is the end opposite to the first end in the first direction L. Furthermore, the positions of the inlet 121 and outlet 122 in the heat exchanger 100 can take various positions depending on the shape of the flow path 34 through which the heat exchange medium flows. The battery 200 is positioned between the inlet 121 and the outlet 122.
[0017] As shown in FIG. 2, the heat exchanger 100 is arranged to face the contact surface (e.g., the lower surface in FIG. 2) of the battery 200. A heat conductive material (not shown) may be arranged between the heat exchanger 100 and the battery 200.
[0018] In the heat exchanger 100, the first direction L may correspond to the longitudinal direction of the electric vehicle, and the second direction S may correspond to the lateral direction of the electric vehicle, or the first direction L may correspond to the lateral direction of the electric vehicle, and the second direction S may correspond to the longitudinal direction of the electric vehicle.
[0019] <The first plate member 10> The first plate member 10 is a substantially rectangular plate-like member configured to face the contact surface of the battery 200. The first plate member 10 is made of a metal with high thermal conductivity such as aluminum, for example. Note that the first plate member 10 may be made of a metal with high corrosion resistance such as stainless steel. The first plate member 10 is parallel to the neutral axis N extending along the second direction S in a cross section (hereinafter simply referred to as a cross section) orthogonal to the first direction L of the heat exchanger 100, and extends substantially planar along the first direction L and the second direction S. Here, the neutral axis N indicates a line where the neutral plane, which is a surface where neither compressive strain nor tensile strain occurs in an object, intersects the cross section in a composite material in which the first plate member 10 and the second plate member 20 are joined by welding. At the neutral axis N, even if a bending moment acts on the object, the tensile force and the compressive force balance each other, and no stress intensity occurs in the cross section.
[0020] <The second plate member 20> The second plate member 20 is arranged to face the surface of the first plate member 10 opposite to the battery 200 (e.g., the lower surface in FIG. 2), and is a substantially rectangular plate-like member that forms a flow path 34 through which a heat exchange medium passes between the second plate member 20 and the first plate member 10. In the present embodiment, five flow paths 34 are formed as shown in FIG. 2.
[0021] For example, if the contact surface of the battery 200 mounted on the electric vehicle extends in a substantially horizontal direction, the second plate member 20 is positioned below or above the first plate member 10. Also, for example, if the contact surface of the battery 200 mounted on the electric vehicle extends in a substantially vertical direction, the second plate member 20 is positioned to the left, right, front, or rear of the first plate member 10. The second plate member 20 is made of a metal with high thermal conductivity, such as aluminum, similar to the first plate member 10. The second plate member 20 may also be made of a metal with high corrosion resistance, such as stainless steel.
[0022] As shown in Figure 2, the second plate member 20 comprises a plurality of contact portions 21, a plurality of separation portions 22, and a plurality of connecting portions 23. The contact portions 21 are portions having surfaces that contact the first plate member 10, extending along a first direction L, and parallel to the neutral axis N. The separation portions 22 are portions having surfaces parallel to the contact portions 21 and further away from the first plate member 10 than the contact portions 21, extending along the first direction L, and parallel to the neutral axis N. The connecting portions 23 continuously connect the contact portions 21 and the separation portions 22 along the first direction L. The connecting portions 23 have planes that intersect with the contact portions 21 and the separation portions 22. Each space enclosed by the first member, the separation portions 22, and the connecting portions 23 is configured to function as a flow path 34.
[0023] <Welded joints 31, 32> The welded portions 31 and 32 are areas where the first plate member 10 and the second plate member 20 are joined by welding, and are areas that extend linearly along the first direction L. Multiple welded portions 31 and 32 are each formed on one of the contact portions 21. Each of the multiple welded portions 31 and 32 extends linearly along the first direction L and is formed in a line along the second direction S which is perpendicular to the first direction L. As shown in Figures 1 to 3, the welded portion 31 is formed along the outer circumference of the first plate member 10 and the second plate member 20, and has portions formed not only along the first direction L but also along the second direction S.
[0024] On the other hand, the welded portion 32 is formed in the portion of the contact portion 21 that is located between the multiple flow channels 34. In other words, the welded portion 32 is formed to partition the multiple flow channels 34. As shown in Figure 2, the welded joints 31 and 32 are formed by heat input from the second plate member 20 side. This is to ensure that the weld line (i.e., weld bead) caused by the melting of the material is formed only on the second plate member 20 side and is less likely to form on the battery 200 side of the first plate member 10. With this configuration, the heat exchanger 100 can be made less prone to unevenness on the battery 200 side of the first plate member 10, so that heat exchange can be performed smoothly without gaps forming between it and the battery 200.
[0025] <Heat input section 33> The heat input section 33 is a portion of at least one of the first plate member 10 and the second plate member 20 that is heated without being joined to the other member. In other words, the heat input section 33 is a portion that is heated and then shrinks when cooled, generating a bending force. In this embodiment, as shown in Figure 2, two heat input sections 33 are formed, each extending linearly along the first direction L. The two heat input sections 33 are arranged symmetrically with respect to the center CS in the second direction of the heat exchanger 100. That is, as shown in Figure 2, the two heat input sections 33 are positioned at a distance W from the center CS, flanking the center CS.
[0026] <Arrangement of welded parts 31, 32 and heat input part 33> As shown in Figure 3, the welded sections 31, 32 and the heat input section 33 are formed symmetrically with respect to the center CL of the first direction L. In other words, if we assume that the welded sections 31, 32 and the heat input section 33 are line segments extending along the first direction, the midpoints of these line segments coincide with the center CL. Therefore, in the first direction L, the midpoint of the heat input section 33 and the midpoints of the welded sections 31, 32 are set to be in the same position.
[0027] Furthermore, the heat input section 33 extends along the first direction L by a distance L1 from the center CL, sandwiching the center CL. Similarly, the welded section 32 extends along the first direction L by a distance L2 from the center CL, sandwiching the center CL, and the welded section 31 extends along the first direction L by a distance L3 from the center CL, sandwiching the center CL.
[0028] Furthermore, as shown in Figure 2, the welded sections 31 and 32 and the heat input section 33 are positioned so as to straddle the neutral axis N of the heat exchanger 100 in a cross section perpendicular to the first direction L. In the example shown in Figure 2, since the welded sections 31 and 32 are located slightly above the neutral axis N, when thermal contraction occurs, a bending force is applied to the heat exchanger 100 that causes it to become convex downwards.
[0029] In contrast, since the heat input section 33 is formed below the neutral axis N, when thermal contraction occurs, a bending force is applied to the heat exchanger 100 that causes it to become convex upwards. In this way, the bending force generated by the welded sections 31 and 32 is offset by the bending force generated by the heat input section 33, making the heat exchanger 100 less prone to deformation.
[0030] To further optimize the deformation of the heat exchanger 100, for example, the following can be done. For example, the product of the distance Ha to Hf from one weld 31, 32 to the neutral axis N and the heat quantity Qa to Qf required to form this weld 31, 32 is calculated for each weld 31, 32, and the sum of these products is taken as the welding heat quantity Q1. Also, the product of the distance Hg to Hh from one heat input section 33 to the neutral axis N and the heat quantity Qg to Qh required to form this heat input section 33 is calculated for each heat input section 33, and the sum of these products is taken as the heat input quantity Q2. In such a configuration, the heat input quantity Q2 is configured to match the welding heat quantity Q1.
[0031] In other words, the left side of the following equation represents the welding heat quantity Q1, and the right side represents the heat input quantity Q2. The amount of heat input to the first plate member 10 and the second plate member 20 to form the respective welds 31, 32 and heat input section 33 is adjusted so that the following equation holds true. For the welds 31 and 32, a positive value is set for the distance when they are located above the neutral axis N, and a negative value is set for the distance when they are located below the neutral axis N. For the heat input section 33, a positive value is set for the distance when it is located below the neutral axis N, and a negative value is set for the distance when it is located above the neutral axis N.
[0032]
number
[0033] As described above, the amount of heat input in the welded sections 31 and 32 and the heat input section 33 is thought to be obtained by multiplying the welding output divided by the welding speed by the welding length. [1-2. Effects] The embodiments described in detail above produce the following effects.
[0034] (1a) One aspect of the present disclosure is a heat exchanger 100 configured to exchange heat with a battery 200 mounted on an electric vehicle. The heat exchanger 100 comprises a first plate member 10, a second plate member 20, at least one welded portion 31, 32, and at least one heat input portion 33. The first plate member 10 is a plate-shaped member configured to face the battery 200. The second plate member 20 is a plate-shaped member positioned to face the side of the first plate member 10 opposite to the battery 200, and forming a flow path 34 between itself and the first plate member 10 through which a heat exchange medium passes.
[0035] The welded sections 31 and 32 are portions where the first plate member 10 and the second plate member 20 are joined by welding, and which extend linearly along the first direction L. The heat input section 33 is a portion of at least one of the first plate member 10 and the second plate member 20 that is heated without being joined to other members. The welded sections 31 and 32 and the heat input section 33 are positioned so as to straddle the neutral axis N of the heat exchanger 100 in a cross section perpendicular to the first direction L.
[0036] With this configuration, bending forces are generated in the welded parts 31 and 32 due to thermal contraction, but the heat exchanger 100 has a heat input section 33 formed on the opposite side of the welded parts 31 and 32, with the neutral axis N in between. Therefore, a bending force can be generated in the opposite direction to the bending force caused by the welded parts 31 and 32. In other words, by generating thermal strain on the side opposite to the side where the effect of thermal strain is greater than that of the neutral axis N, the balance of thermal strain can be maintained. Therefore, with this configuration, the bending force caused by the welded parts 31 and 32 can be offset by the bending force in the opposite direction from the heat input section 33. Consequently, bending deformation in the heat exchanger 100 can be suppressed with a simpler process compared to bending.
[0037] (1b) In one aspect of the present disclosure, the heat input portion 33 is a portion formed to extend linearly along a first direction L. With this configuration, since the heat input portion 33 and the welded portions 31, 32 are arranged in parallel, the bending force can be suppressed along the direction in which the portion where the bending force is generated extends (i.e., the first direction L).
[0038] (1c) In one aspect of the present disclosure, in the first direction L, the midpoint of the heat input portion 33 and the midpoints of the welded portions 31 and 32 are set to the same position. With this configuration, since the positions of the midpoints are aligned in the first direction L, the bending force near the midpoint in the first direction L can be effectively suppressed.
[0039] (1d) In one aspect of the present disclosure, the heat exchanger 100 is provided with a plurality of heat input sections 33, where at least one heat input section 33 is a plurality of heat input sections 33. In this configuration, the plurality of heat input sections 33 are arranged symmetrically with respect to the center CS of the second direction S in the heat exchanger 100. With this configuration, the bending force in the heat input sections 33 is generated uniformly with respect to the center CS of the second direction S, so that unwanted bending forces in the second direction S are less likely to be generated.
[0040] (1e) In one aspect of the present disclosure, the product of the distance from one weld 31, 32 to the neutral axis N and the amount of heat required to form the weld 31, 32 is calculated for each weld 31, 32, and the sum of these products is defined as the welding heat quantity Q1. In addition, the product of the distance from one heat input section 33 to the neutral axis N and the amount of heat required to form the heat input section 33 is calculated for each heat input section 33, and the sum of these products is defined as the heat input quantity Q2. In this configuration, the heat input quantity Q2 is configured to be the same as the welding heat quantity Q1.
[0041] With this configuration, the bending forces across the neutral axis N can be made approximately the same. Therefore, the bending deformation of the heat exchanger 100 can be suppressed. Note that "approximately the same" may include "approximately the same".
[0042] [2. Other Embodiments] Although embodiments of the present disclosure have been described above, the present disclosure is not limited to the embodiments described above and can be implemented in various modified forms.
[0043] (2a) In the above embodiment, two examples of heat input sections 33 were shown, but the invention is not limited thereto. There may be more or fewer than two heat input sections 33. For example, as in the first modified example heat exchanger 101 shown in Figure 4A, there may be only one heat input section 33, or as in the second modified example heat exchanger 102 shown in Figure 4B, there may be three heat input sections 33. In cases other than two heat input sections 33, it is preferable that the heat input sections 33 be arranged symmetrically with respect to the center CS in the second direction S. Furthermore, when three or more heat input sections 33 are formed, it is preferable that each heat input section 33 be arranged at equal intervals in the second direction S.
[0044] (2b) In the above embodiment, a configuration in which the first plate member 10 is a flat plate has been described, but the invention is not limited to this. For example, as shown in Figures 5A to 5C, the first plate member 10 may be bent near the end in the second direction S so as to be convex upward. In such a configuration, the welded parts 31 and 32 may be formed on either side of the neutral axis N, and the heat input part 33 should be appropriately positioned according to the length of the welded parts 31 and 32, the amount of heat input, etc.
[0045] For example, in the case of a heat exchanger 103 of the third modified example shown in Figure 5A, where the effect of thermal contraction is large above the neutral axis N, it is preferable to form the heat input portion 33 below the neutral axis N, similar to the configuration of the embodiment.
[0046] Furthermore, for example, as in the heat exchanger 104 of the fourth modified example shown in Figure 5B, if the effect of thermal contraction is large below the neutral axis N, it is preferable to form the heat input section 33 above the neutral axis N. In this case, it is preferable to form the heat input section 33 from the second plate member 20 side. In the example in Figure 5B, the heat input section 33 is formed adjacent to the welded section 32 so as to be parallel to it.
[0047] Furthermore, if the effect of thermal shrinkage is significant below the neutral axis N, a heat input portion 33 may be formed on the first plate member 10, as shown in the fifth modified example heat exchanger 105 in Figure 5C. However, it is preferable to flatten the contact surface of the first plate member 10 with the battery 200 by grinding off the weld bead.
[0048] (2c) Multiple functions of one component in the above embodiment may be realized by multiple components, or one function of one component may be realized by multiple components. Also, multiple functions of multiple components may be realized by one component, or one function realized by multiple components may be realized by one component. Furthermore, some of the configuration of the above embodiment may be omitted. Furthermore, at least some of the configuration of the above embodiment may be added to or replaced with the configuration of other above embodiments.
[0049] (2d) In addition to the heat exchangers 100 to 105 described above, this disclosure can also be realized in various forms, such as systems, vehicles, and heat exchange methods that use the heat exchangers 100 to 105 as components.
[0050] [Technical concepts disclosed in this specification] [Item 1] A heat exchanger configured to exchange heat with a battery mounted on an electric vehicle, A first plate member, which is a plate-shaped member, is configured to face the battery, A second plate member, which is a plate-shaped member, is positioned facing the side of the first plate member opposite to the battery, and forms a flow path between it and the first plate member through which a heat exchange medium passes. The portion where the first plate member and the second plate member are joined by welding, and which extends along the first direction, includes at least one welded portion, At least one of the first plate member and the second plate member has at least one heat-input portion which is a part that is heated without being joined to other members, Equipped with, The welded portion and the heat input portion are positioned so as to straddle the neutral axis of the heat exchanger in a cross-section perpendicular to the first direction. heat exchanger. [Item 2] The heat exchanger described in item 1, The heat input portion is a part formed to extend along the first direction. heat exchanger. [Item 3] A heat exchanger as described in item 2, In the first direction, the midpoint of the heat input portion and the midpoint of the welded portion are at the same position. heat exchanger. [Item 4] A heat exchanger described in any one of items 1 to 3, The aforementioned at least one heat input section comprises a plurality of heat input sections, In the aforementioned cross-section, the direction in which the neutral axis extends is defined as the second direction. The plurality of heat input sections are arranged symmetrically with respect to the center in the second direction of the heat exchanger. heat exchanger. [Item 5] A heat exchanger described in any one of items 1 to 4, The at least one welded joint comprises multiple welded joints, The aforementioned at least one heat input section comprises a plurality of heat input sections, The product of the distance from each weld to the neutral axis and the amount of heat required to form that weld is calculated for each weld, and the sum of these products is taken as the welding heat. The product of the distance from one heat input point to the neutral axis and the amount of heat required to form that heat input point is calculated for each heat input point, and the sum of these products is taken as the total heat input. The heat input is configured to match the welding heat. heat exchanger. [Explanation of symbols]
[0051] 10...First plate member, 20...Second plate member, 21...Contact part, 22...Separation part, 23...Connection part, 31,32...Welded part, 33...Heat input part, 34...Flow path, 100~105...Heat exchanger, 121...Inlet, 122...Outlet, 200...Battery.
Claims
1. A heat exchanger configured to exchange heat with a battery mounted on an electric vehicle, A first plate member, which is a plate-shaped member, is configured to face the battery, A second plate member, which is a plate-shaped member, is positioned facing the side of the first plate member opposite to the battery, and forms a flow path between it and the first plate member through which a heat exchange medium passes. The portion where the first plate member and the second plate member are joined by welding, and which extends along the first direction, includes at least one welded portion, At least one of the first plate member and the second plate member has at least one heat-input portion which is a part that is heated without being joined to other members, Equipped with, The welded portion and the heat input portion are positioned so as to straddle the neutral axis of the heat exchanger in a cross section perpendicular to the first direction. heat exchanger.
2. A heat exchanger according to claim 1, The heat input portion is a part formed to extend along the first direction. heat exchanger.
3. A heat exchanger according to claim 2, In the first direction, the midpoint of the heat input portion and the midpoint of the welded portion are at the same position. heat exchanger.
4. A heat exchanger according to any one of claims 1 to 3, The aforementioned at least one heat input section comprises a plurality of heat input sections, In the aforementioned cross-section, the direction in which the neutral axis extends is defined as the second direction. The plurality of heat input sections are arranged symmetrically with respect to the center in the second direction of the heat exchanger. heat exchanger.
5. A heat exchanger according to any one of claims 1 to 3, The at least one welded joint comprises multiple welded joints, The aforementioned at least one heat input section comprises a plurality of heat input sections, The product of the distance from each weld to the neutral axis and the amount of heat required to form that weld is calculated for each weld, and the sum of these products is taken as the welding heat quantity. The product of the distance from one heat input point to the neutral axis and the amount of heat required to form that heat input point is calculated for each heat input point, and the sum of these products is taken as the total heat input. The heat input is configured to match the welding heat. heat exchanger.