A heat exchanger

Abstract

The application discloses a heat exchanger, which comprises a core body, the core body comprises a first plate and a second plate, the core body has a first fluid channel and a second fluid channel, the first fluid channel comprises a first inter-plate channel, the second fluid channel comprises a second inter-plate channel, the core body has a first isolation part and a second isolation part, the first isolation part is located on the first plate, the first isolation part has a first welding part, a second welding part and a first main body part, the first welding part has a first welding surface, the first welding surface is welded and fixed with the second plate adjacent to one side of the first plate, so that the first isolation part separates the first inter-plate channel into a first sub-inter-plate channel and a second sub-inter-plate channel, the second welding part has a second welding surface, the second welding surface is welded and fixed with the second plate adjacent to the other side of the first plate, so that the second isolation part separates the second inter-plate channel into a third sub-inter-plate channel and a fourth sub-inter-plate channel. The cooperation requirement of the isolation part can be reduced, and the heat exchanger is easy to install and process.

Description

Technical Field

[0001] This invention relates to the field of heat exchange technology, and in particular to a heat exchanger. Background Technology

[0002] Plate heat exchangers offer high heat exchange efficiency, are compact, and relatively lightweight, making them suitable for various industries such as refrigeration, chemical processing, and water treatment. The basic principle of a plate heat exchanger is that two heat exchange media exchange heat through heat exchange plates in adjacent flow channels. As the application scenarios for plate heat exchangers increase, the performance requirements for them are also constantly rising. In a U-shaped plate channel heat exchanger, although the channel is relatively long, the structure of the middle blocking section of the plates uses a nested stacking method, requiring high precision in the fit between the plates. Summary of the Invention

[0003] The purpose of this invention is to provide a heat exchanger with an isolation section that is easy to install and convenient to process.

[0004] A heat exchanger is provided, comprising a core, the core including a first plate and a second plate stacked thereon, the core having a first fluid channel and a second fluid channel isolated from each other, the first fluid channel including a first inter-plate channel located between the first plate and the second plate, the second fluid channel including a second inter-plate channel located between the second plate and the first plate, the core having a first isolation portion and a second isolation portion, the first isolation portion being located on the first plate and the second isolation portion being located on the second plate; the first isolation portion having a first welded portion, a second welded portion and a first main body portion, the first main body portion being located between the first welded portion and the second welded portion. The first welding part has a first welding surface facing the second plate adjacent to the first plate on one side, and the first welding surface is welded and fixed to the second isolation part on the second plate adjacent to the first plate on one side, such that the first isolation part divides the first inter-plate channel into a first sub-plate channel and a second sub-plate channel. The second welding part has a second welding surface facing the second plate adjacent to the other side of the first plate, and the second welding surface is welded and fixed to the second isolation part on the second plate adjacent to the other side of the first plate, such that the second isolation part divides the second inter-plate channel into a third sub-plate channel and a fourth sub-plate channel.

[0005] The first plate includes a first isolation portion, which has a first welding portion and a second welding portion. The first welding portion has a first welding surface, which is welded and fixed to the second isolation portion on a second plate adjacent to one side of the first plate, so that the first isolation portion divides the first plate inter-channel into a first sub-plate inter-channel and a second sub-plate inter-channel. The second welding portion has a second welding surface, which is welded and fixed to the second isolation portion on a second plate adjacent to the other side of the first plate, so that the second isolation portion divides the second plate inter-channel into a third sub-plate inter-channel and a fourth sub-plate inter-channel. This reduces the fitting requirements of the isolation portion and makes it easy to install and process. Attached Figure Description

[0006] Figure 1 This is a perspective view of one embodiment of the heat exchanger in this invention;

[0007] Figure 2 This is a schematic diagram of the structure of the first plate of an embodiment of the heat exchanger in this invention;

[0008] Figure 3 This is another structural schematic diagram of the first plate of an embodiment of the heat exchanger in this invention;

[0009] Figure 4 This is a schematic diagram of the structure of the second plate in one embodiment of the heat exchanger of the present invention;

[0010] Figure 5 This is another structural schematic diagram of the second plate of an embodiment of the heat exchanger in this invention;

[0011] Figure 6 This is a partial cross-sectional view of one embodiment of the heat exchanger in this invention;

[0012] Figure 7 This is a schematic diagram of the structure of the first plate of another embodiment of the heat exchanger in this invention;

[0013] Figure 8 This is another structural schematic diagram of the first plate of another embodiment of the heat exchanger in this invention;

[0014] Figure 9 This is a schematic diagram of the structure of the second plate in another embodiment of the heat exchanger of the present invention;

[0015] Figure 10 This is a partial cross-sectional view of another embodiment of the heat exchanger in this invention;

[0016] Figure 11 This is a top view of a partial structure of another embodiment of the present invention.

[0017] Figure label:

[0018] Core 10,

[0019] First plate 1, first middle section 11, first flange 12

[0020] First isolation section 13, first welding section 131, first welding surface 1311, second welding section 132, second welding surface 1321, first main body section 133, fourth welding section 134, fourth welding surface 1341, fourth main body section 135, fifth main body section 136, fifth welding section 137, sixth welding surface 1371, fourth isolation section 14, eighth welding surface 141.

[0021] Second plate 2, second middle section 21, second flange 22

[0022] Second isolation section 23, third welding section 231, third welding surface 2311, fifth welding surface 2312, second main body section 232, third main body section 233, third isolation section 24, seventh welding surface 2411. Detailed Implementation

[0023] To enable those skilled in the art to better understand the present invention, the present invention will be further described below in conjunction with the accompanying drawings and specific embodiments.

[0024] In this document, terms such as "upper," "lower," "left," and "right" are established based on the positional relationships shown in the accompanying drawings. Depending on the drawings, the corresponding positional relationships may change. Therefore, they should not be interpreted as absolute limitations on the scope of protection. Moreover, relational terms such as "first" and "second" are merely used to distinguish one component from another with the same name, and do not necessarily require or imply any such actual relationship or order between these components. "Connected" refers to direct connection or indirect connection through other channels.

[0025] refer to Figures 1-6 A heat exchanger includes a core 10, which includes a first plate 1 and a second plate 2 stacked together. The first plate 1 includes a first central portion 11 and a first flange 12 located on the periphery of the first central portion 11. The first central portion 11 is generally rectangular, and corner holes are provided near its corners. The second plate 2 includes a second central portion 21 and a second flange 22 located on the periphery of the second central portion 21. The second central portion 21 is generally rectangular, and corner holes are provided near its corners. The first plate 1 and the second plate 2 are stacked sequentially, and the first flange 12 and the second flange 22 are welded to form the core 10. The corner holes on the width direction side of the first central portion 11 are opposite to the corner holes on the width direction side of the second central portion 21 to form a first channel and a second channel. The corner holes on the other width direction side of the first central portion 11 are opposite to the corner holes on the other width direction side of the second central portion 21 to form a third channel and a fourth channel.

[0026] refer to Figures 1-6 The core 10 has a first fluid channel and a second fluid channel that are isolated from each other. The first fluid channel includes a first channel and a second channel located on one side of the core 10 in the same width direction. The first fluid channel also includes a first inter-plate channel located between the first plate 1 and the second plate 2. The first inter-plate channel connects the first channel and the second channel. The second fluid channel includes a third channel and a fourth channel located on the other side of the core 10 in the same width direction. The second fluid channel also includes a second inter-plate channel located between the second plate 2 and the first plate 1. The second inter-plate channel connects the third channel and the fourth channel.

[0027] refer to Figures 1-6 The core 10 has a first isolation portion 13 and a second isolation portion 23. The first isolation portion 13 is located on the first plate and has a first welding portion 131, a second welding portion 132, and a first main body portion 133. The first main body portion 133 is located between the first welding portion 131 and the second welding portion 132. The first welding portion 131 has a first welding surface 1311, which faces the second plate 2 adjacent to the first plate 1 on one side, and the first welding surface 1311 is adjacent to the second plate 2 on one side of the first plate 1. The second isolation portion 23 is welded and fixed, so that the first isolation portion 13 divides the first inter-plate channel into a first sub-plate channel and a second sub-plate channel. The second welding portion 132 has a second welding surface 1321, which faces the second plate 2 adjacent to the other side of the first plate 1. The second welding surface 1321 is welded and fixed to the second isolation portion 23 on the second plate 2 adjacent to the other side of the first plate 1, so that the second isolation portion 23 divides the second inter-plate channel into a third sub-plate channel and a fourth sub-plate channel.

[0028] This heat exchanger includes a first plate 1, which includes a first isolation portion 1313. The first isolation portion 1313 has a first welding portion 131 and a second welding portion 132. The first welding portion 131 has a first welding surface 1311, which is welded and fixed to a second isolation portion 23 on a second plate 2 adjacent to one side of the first plate 1. This allows the first isolation portion 13 to divide the first inter-plate channel into a first sub-plate channel and a second sub-plate channel. The second welding portion 132 has a second welding surface 1321, which is welded and fixed to a second isolation portion 23 on a second plate 2 adjacent to the other side of the first plate 1. This allows the second isolation portion 23 to divide the second inter-plate channel into a third sub-plate channel and a fourth sub-plate channel. This reduces the fitting requirements of the isolation portion and makes it easier to install and process.

[0029] refer to Figures 2-3 , Figure 6Along the stacking direction of the core 10, the first welding part 131 protrudes from the first middle part. The first isolation part 13 has a fourth welding part 134 and a fourth main body part 135. The fourth main body part 135 is located between the first welding part 131 and the fourth welding part 134. The fourth main body part 135 is generally opposite to the second main body part 232. The second main body part 232 is inclined relative to the first middle part 11, and the fourth main body part 135 is inclined relative to the first middle part 11. The inclination directions of the second main body part 232 and the fourth main body part 135 relative to the first middle part 11 are opposite. That is, the second main body part 232 and the fourth main body part 135 are generally in the shape of an "eight", which is convenient for molding.

[0030] refer to Figures 2-3 , Figure 6 The first isolation portion 13 has a fifth main body portion 136 and a fifth welding portion 137. The fifth main body portion 136 is located between the second main body portion 232 and the fourth main body portion 135. The fifth main body portion 136 is located between the first welding portion 131 and the fifth welding portion 137. The fifth welding portion 137 is located between the second welding portion 132 and the fourth welding portion 134. The fifth main body portion 136 is generally U-shaped and extends along the width direction of the first plate 1. The second main body portion 232 and the fourth main body portion 135 are located on both sides of the opening of the U-shaped fifth main body portion 136 and extend along the length direction of the first plate 1.

[0031] refer to Figures 2-3 , Figure 6 The second welding part 132, the fourth welding part 134, the fifth welding part 137, and the first middle part are coplanar. That is, the upper surfaces of the second welding part 132, the fourth welding part 134, the fifth welding part 137, and the first middle part 11 are located on the same plane. The lower surfaces of the second welding part 132, the fourth welding part 134, the fifth welding part 137, and the first middle part 11 are located on the same plane. The fifth welding part 137 is approximately U-shaped. Along the width direction of the first plate 1, the second welding part 132 and the fourth welding part 134 are located on both sides of the U-shaped fifth welding part 137, and the second welding part 132 and the fourth welding part 134 extend along the length direction of the first plate 1, which facilitates molding and saves costs.

[0032] refer to Figures 4-6 The second plate 2 includes a second middle portion 21, and a second isolation portion 23 is located on the second plate 2. The second isolation portion 23 has a third welding portion 231, a second main body portion 232 and a third main body portion 233. Along the stacking direction of the core 10, the third welding portion 231 protrudes from the second middle portion 21, and the second main body portion 232 and the third main body portion 233 are located on both sides of the third welding portion 231. The second main body portion 232 and the third main body portion 233 are generally opposite to each other.

[0033] refer to Figures 1-6 The fourth welding part 134 has a fourth welding surface 1341, which faces the second plate 2 adjacent to the first plate 1. The third welding part 231 has a third welding surface 2311, which faces the first plate 1 adjacent to the second plate 2. The second welding surface 1321 is welded to the third welding surface 2311. The fourth welding surface 1341 is welded to the third welding surface 2311. The fifth welding part 137 has a sixth welding surface 1371, which faces the second plate 2 adjacent to the first plate 1 and is welded to the third welding surface 2311. The third welding part 231 has a fifth welding surface 2322, which faces the second plate adjacent to the other side of the second plate. The fifth welding surface 2322 is welded to the first welding surface 1311. This reduces the stamping depth of the first isolation part 13 and / or the second isolation part 23, reduces the thinning rate of the plates, and improves the corrosion resistance of the plates.

[0034] The first plate 1 also includes a fourth isolation portion 14, which protrudes from the first middle portion 11. The end of the fourth isolation portion 14 away from the first isolation portion 13 is connected to the first flange 12, while the end of the first isolation portion 13 away from the fourth isolation portion 14 is not connected to the first flange 12. The top wall of the fourth isolation portion 14 forms a seventh welding portion, which has an eighth welding surface 141. The eighth welding surface 141 faces the second plate 2 adjacent to one side of the first plate 1, and the eighth welding surface 141 is welded and fixed to the second plate 2 adjacent to one side of the first plate 1. In the length direction of the first plate 1, there is a gap between the end of the fourth isolation portion 14 away from the first isolation portion 13 and the first flange 12 to allow fluid to flow from the first sub-plate inter-channel to the second sub-plate inter-channel.

[0035] The second plate 2 also includes a third isolation portion 24. Along the stacking direction of the core 10, the third isolation portion 24 protrudes from the second middle portion 21. The top wall of the third isolation portion 24 forms a sixth welding portion. The sixth welding portion has a seventh welding surface 2411. The seventh welding surface 2411 faces the first plate 1 adjacent to the second plate 2 on one side, and the seventh welding surface 2411 is welded and fixed to the first plate 1 adjacent to the second plate 2 on one side. One end of the third isolation portion 24 is connected to the second flange 22, and the other end of the third isolation portion 24 is connected to the second isolation portion 23.

[0036] refer to Figures 7-8 , Figure 10 Along the opposite direction of the core 10 layers, the second welding part 132 protrudes from the first middle part 11, and the second isolation part 23 has the second welding part 132 and the second main body part 232, with the second main body part 232 located between the first middle part and the second welding part 132.

[0037] refer to Figures 7-8 , Figure 10 The first isolation portion 13 has a third main body portion 233 and a third welding portion 231. The third main body portion 233 is located between the first welding portion 131 and the third welding portion 231. The third main body portion 233 and the first main body portion 133 are located on both sides of the first welding portion 131. The third main body portion 233 is generally opposite to the first main body portion 133. Along the opposite direction of the core stacking, the third welding portion 231 protrudes from the first middle portion. The second isolation portion 23 has a third welding portion 231 and a fourth main body portion 135. The fourth main body portion 135 is located between the third welding portion 231 and the first middle portion.

[0038] refer to Figures 7-8 , Figure 10 The first isolation portion 13 has a fifth main body portion 136 and a fifth welding portion 137. The fifth main body portion 136 is located between the first main body portion 133 and the third main body portion 233. The fifth main body portion 136 is located between the first welding portion 131 and the fifth welding portion 137. Along the opposite direction of the core stacking, the fifth welding portion 137 protrudes from the first middle portion 11. The second isolation portion 23 has a fifth welding portion 137 and a sixth main body portion. The sixth main body portion is located between the first middle portion of the fifth welding portion 137. The sixth main body portion is generally U-shaped. Along the width direction of the first plate 1, the second main body portion 232 and the fourth main body portion 135 are located on both sides of the opening of the U-shaped sixth main body portion 137, and the second main body portion 232 and the fourth main body portion 135 extend along the length direction of the first plate 1.

[0039] refer to Figures 7-10 The first middle part 11 has a fourth welding surface 1341 and a fifth welding surface. The fourth welding surface 1341 faces the first plate 1 adjacent to the second plate 2 on one side, and the fifth welding surface faces the first plate 1 adjacent to the other side of the second plate 2. The second welding surface 1321 is welded to the fourth welding surface 1341. The third welding part 231 has a third welding surface 2311. The third welding surface 2311 faces the second plate 2 adjacent to the first plate 1 on one side, and the third welding surface 2311 is welded to the fourth welding surface 1341. The fifth welding part 137 has a sixth welding surface 1371. The sixth welding surface 1371 faces the second plate 2 adjacent to the first plate 1 on one side, and the sixth welding surface 1371 is welded to the fourth welding surface 1341.

[0040] The second plate 2 includes a second flange 22 located at the periphery of the second middle portion 21. The second plate 2 includes a third isolation portion 24. Along the stacking direction of the core 10, the third isolation portion 24 protrudes from the second middle portion 21. The top wall of the third isolation portion 24 forms a sixth welding portion. The sixth welding portion has a seventh welding surface 2411. The seventh welding surface 2411 faces the first plate 1 adjacent to the second plate 2 on one side, and the seventh welding surface 2411 is welded and fixed to the first plate 1 adjacent to the second plate 2 on one side. One end of the third isolation portion 24 is connected to the second flange 22, and the other end of the third isolation portion 24 is connected to the fifth main body portion 136, making the heat exchanger structure more compact.

[0041] The first plate 1 includes a first middle portion 11. Along the stacking direction of the core 10, a first welding portion 131 protrudes from the first middle portion 11. Along the opposite direction of the stacking of the core 10, a second welding portion 132 protrudes from the first middle portion 11. The first isolation portion 13 includes a second main body portion 232, which is located between the first middle portion 11 and the second welding portion 132.

[0042] The second plate 2 includes a third welding portion 231 and a third main body portion 233. The second plate 2 includes a second middle portion 21. Along the stacking direction of the core 10, the third welding portion 231 protrudes from the second middle portion 21. The third main body portion 233 is located between the second middle portion 21 and the third welding portion 231. The third welding portion 231 has a third welding surface 2311. The third welding surface 2311 faces the first plate 1 on the adjacent side of the second plate 2, and the second welding surface 1321 is welded and fixed to the third welding surface 2311. The second isolation portion 23 includes a second welding portion 132, a second main body portion 232, a third welding portion 231, and a fourth main body portion 135.

[0043] The first isolation portion 13 has a fourth main body portion 135 and a fourth welding portion 134. Along the opposite direction of the stacking of the core 10, the fourth welding portion 134 protrudes from the first middle portion 11. The fourth main body portion 135 is located between the first middle portion 11 and the fourth welding portion 134. The fourth main body portion 135 and the first main body portion 133 are located on both sides of the first welding portion 131. The fourth main body portion 135 and the first main body portion 133 are approximately opposite each other. The fourth welding portion 134 has a fourth welding surface 1341. The fourth welding surface 1341 faces the second plate 2 adjacent to the first plate 1 and is welded to the third welding surface 2311. The first isolation portion 13 has a fifth main body portion 136, which is located between the first middle portion 11 and the fourth welding portion 134.

[0044] This article uses specific examples to illustrate the principles and implementation methods of the present invention. The descriptions of the above embodiments are only for the purpose of helping to understand the core ideas of the present invention. It should be noted that those skilled in the art can make several improvements and modifications to the present invention without departing from the principles of the present invention, and these improvements and modifications also fall within the protection scope of the claims of the present invention.

Claims

1. A heat exchanger, comprising a core, the core including a first plate and a second plate stacked thereon, the core having a first fluid channel and a second fluid channel isolated from each other, characterized in that, The first fluid channel includes a first inter-plate channel located between the first plate and the second plate, and the second fluid channel includes a second inter-plate channel located between the second plate and the first plate. The core has a first isolation portion and a second isolation portion, wherein the first isolation portion is located on the first plate and the second isolation portion is located on the second plate. The first isolation portion has a first welding portion, a second welding portion, and a first main body portion. The first main body portion is located between the first welding portion and the second welding portion. The first welding portion has a first welding surface facing the second plate adjacent to the first plate on one side, and the first welding surface is welded and fixed to the second isolation portion on the second plate adjacent to the first plate on one side, such that the first isolation portion divides the first inter-plate channel into a first sub-plate channel and a second sub-plate channel. The second welding portion has a second welding surface facing the second plate adjacent to the other side of the first plate, and the second welding surface is welded and fixed to the second isolation portion on the second plate adjacent to the other side of the first plate, such that the second isolation portion divides the second inter-plate channel into a third sub-plate channel and a fourth sub-plate channel.

2. The heat exchanger according to claim 1, characterized in that, The second plate includes a second middle portion, the second isolation portion has a third welding portion and a second main body portion, the third welding portion protrudes from the second middle portion along the stacking direction of the core body, the third welding portion has a third welding surface, the third welding surface faces the first plate adjacent to the second plate on one side, and the second welding surface is welded and fixed to the third welding surface.

3. The heat exchanger according to claim 2, characterized in that, The second isolation portion has a third main body portion, the second main body portion and the third main body portion are located on both sides of the third welding portion, and the second main body portion and the third main body portion are generally opposite to each other. The first isolation portion has a fourth welding portion and a fourth main body portion, the fourth main body portion is located between the first welding portion and the fourth welding portion, the fourth main body portion is generally opposite to the second main body portion, the fourth welding portion has a fourth welding surface, the fourth welding surface faces the second plate adjacent to the first plate, and the fourth welding surface is welded and fixed to the third welding surface.

4. The heat exchanger according to claim 3, characterized in that, The first plate includes a first middle portion. The first isolation portion has a fifth main body portion and a fifth welding portion. The fifth main body portion is located between the second main body portion and the fourth main body portion. The fifth main body portion is located between the first welding portion and the fifth welding portion. The second welding portion, the fourth welding portion, the fifth welding portion, and the first middle portion are coplanar. The fifth welding portion is located between the second welding portion and the fourth welding portion. The fifth welding portion has a sixth welding surface. The sixth welding surface faces the second plate adjacent to the first plate on one side. The sixth welding surface is welded and fixed to the third welding surface.

5. The heat exchanger according to claim 2, characterized in that, The first plate includes a first middle portion along the direction of the core stacking, a first weld portion protruding from the first middle portion along the opposite direction of the core stacking, a second weld portion protruding from the first middle portion, a second isolation portion located on the first plate, the second isolation portion having the second weld portion and a second main body portion, the second main body portion being located between the first middle portion and the second weld portion.

6. The heat exchanger according to claim 5, characterized in that, The first isolation portion has a third main body portion and a third welding portion. The third main body portion is located between the first welding portion and the third welding portion. The third main body portion and the first main body portion are located on both sides of the first welding portion. The third main body portion is generally opposite to the first main body portion. Along the opposite direction of the core stacking, the third welding portion protrudes from the first middle portion. The third welding portion has a third welding surface. The third welding surface faces the second plate adjacent to the first plate on one side, and the third welding surface is welded and fixed to the second plate adjacent to the first plate on one side. The second isolation portion has the third welding portion and the fourth main body portion, the fourth main body portion being located between the first middle portion of the third welding portion.

7. The heat exchanger according to claim 6, characterized in that, The first isolation portion has a fifth main body portion and a fifth welding portion. The fifth main body portion is located between the first main body portion and the third main body portion. The fifth main body portion is located between the first welding portion and the fifth welding portion. Along the opposite direction of the core stacking, the fifth welding portion protrudes from the first middle portion. The fifth welding portion has a sixth welding surface. The sixth welding surface faces the second plate adjacent to the first plate on one side, and the sixth welding surface is welded and fixed to the second plate adjacent to the first plate on one side. The second isolation portion has the fifth welding portion and the sixth main body portion, the sixth main body portion being located between the first middle portion of the fifth welding portion.

8. The heat exchanger according to claim 7, characterized in that, The second plate includes a second flange located at the periphery of the second middle portion. The second plate includes a third isolation portion. Along the stacking direction of the core, the third isolation portion protrudes from the second middle portion. The top wall of the third isolation portion forms a sixth welding portion. The sixth welding portion has a seventh welding surface. The seventh welding surface faces the first plate adjacent to one side of the second plate and is welded and fixed to the first plate adjacent to one side of the second plate. One end of the third isolation portion is connected to the second flange, and the other end of the third isolation portion is connected to the fifth main body portion.

9. The heat exchanger according to claim 1, characterized in that, The first plate includes a first middle portion along the direction of the core stacking, the first weld portion protrudes from the first middle portion along the opposite direction of the core stacking, the second weld portion protrudes from the first middle portion, and the first isolation portion includes a second main body portion located between the first middle portion and the second weld portion; The second plate includes a third welding portion and a third main body portion. The second plate includes a second middle portion. Along the stacking direction of the core, the third welding portion protrudes from the second middle portion. The third main body portion is located between the second middle portion and the third welding portion. The third welding portion has a third welding surface. The third welding surface faces the first plate adjacent to the second plate, and the second welding surface is welded and fixed to the third welding surface. The second isolation portion has a second welding portion, a second main body portion, the third welding portion, and the third main body portion.

10. The heat exchanger according to claim 9, characterized in that, The first isolation portion has a fourth main body portion and a fourth welding portion. Along the opposite direction of the core stacking, the fourth welding portion protrudes from the first middle portion. The fourth main body portion is located between the first middle portion and the fourth welding portion. The fourth main body portion and the first main body portion are located on both sides of the first welding portion. The fourth main body portion and the first main body portion are approximately opposite each other. The fourth welding portion has a fourth welding surface. The fourth welding surface faces the second plate adjacent to the first plate and is welded to the third welding surface. The first isolation portion has a fifth main body portion. The fifth main body portion is located between the first middle portion and the fourth welding portion.

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