Battery case and method for manufacturing a battery case

Abstract

The present invention provides a battery case and a method for manufacturing the battery case. [Solution] The battery case includes at least two welded bottom plates, each of which has a fourth cavity for allowing a coolant to flow through. Each bottom plate includes a first side wall welded to an adjacent bottom plate, the first side wall having a predetermined width W2. The outermost bottom plate includes a second side wall spaced apart from the first side wall, the second side wall having a predetermined width W3, where 2W2 ≥ W3. The battery case of the present invention solves the problem of battery cases in the prior art, which are difficult to manufacture due to their complex structure.

Description

Technical Field

[0001] The present invention relates to the field of energy storage technology, and particularly to a battery case and a method for manufacturing the battery case.

Background Art

[0002] (Related Application) This application claims the priority of a patent application with an application number of 202311395032.1 and a filing date of October 25, 2023, and the priority of a patent application with an application number of 202322873372.2 and a filing date of October 25, 2023. All the contents of the above patent applications are incorporated herein by reference.

[0003] An energy storage battery is a power storage component required for a solar power generation system. Its main function is to store the power of the solar power generation system and supply power to the load at night and in an emergency when the sunlight intensity is insufficient. The energy storage battery is usually installed inside a battery case. However, the battery case in the prior art has a problem that the manufacturing difficulty is high because the structure of the battery case is complex.

Summary of the Invention

Problems to be Solved by the Invention

[0004] In view of this, the present invention provides a battery case and a method for manufacturing the battery case, which are advantageous for solving the problem existing in the battery case in the prior art that the manufacturing difficulty is high due to the high complexity of the structure of the battery case.

Means for Solving the Problems

[0005] In a first embodiment, the present invention provides a battery case comprising at least two welded bottom plates, each bottom plate having a fourth cavity for the flow of a coolant, each bottom plate including a first side wall welded to an adjacent bottom plate, the first side wall having a predetermined width W2, and the outermost bottom plate including a second side wall spaced apart from the first side wall, the second side wall having a predetermined width W3, satisfying 2W2 ≥ W3.

[0006] A structural plate located at the bottom of the battery case is used to fix and support the batteries located inside the battery case, and this large-area structural plate is composed of at least two smaller bottom plates. Each bottom plate is provided with a fourth cavity for the circulation of coolant. More specifically, the coolant located outside the battery case flows into the fourth cavity. By means of heat conduction, the coolant can absorb the heat generated by the batteries located in the bottom plate during operation. The coolant that has absorbed the heat can be re-flowed to the outside of the bottom plate. By circulating the coolant back and forth within the fourth cavity, the batteries are kept operating within the normal temperature range, and the battery life is improved. As can be seen from the above, the bottom plate is used not only as part of the structural plate of the battery case to fix and support the batteries, but the fourth cavity provided within the bottom plate may also be used to circulate the coolant and achieve heat dissipation. Compared to installing a separate structural plate for fixing and supporting the battery and a separate heat dissipation plate for heat dissipation, the complexity of the structure of the bottom plate and battery case according to the present invention is lower, and the difficulty of manufacturing the bottom plate and battery case is also lower. Next, since the bottom plate in contact with the battery has an integrated heat dissipation function, the formed heat conduction path is short, and the heat from the battery can be quickly conducted to the coolant inside the bottom plate, resulting in high heat dissipation efficiency. Because the area of ​​the structural plate at the bottom of the battery case is large, if a large area structural plate is manufactured all at once using a conventional manufacturing process, the structural strength and dimensional accuracy of the formed structural plate will be relatively inferior. On the other hand, the structural plate at the bottom of the battery case according to the present invention is formed by welding together at least two bottom plates with relatively small areas. With this setup, at least two bottom plates with relatively small areas may be manufactured first in the production process. The structural strength and dimensional accuracy of each bottom plate manufactured using an existing manufacturing process are relatively high. Next, the formed bottom plates may be welded together to form the bottom plate structural plate required for the battery case. The structural strength and dimensional accuracy of the formed structural plate are also relatively high. This allows for better meeting actual usage needs. Here, each bottom plate includes a first side wall, and the first side wall of each bottom plate is welded to the first side wall of the adjacent bottom plate; that is, the two welded first side walls form a connecting structure between the two bottom plates. The welding method has the advantage of providing a strong and reliable connection structure.The outermost bottom plate further includes a second side wall, the second side wall being structured to satisfy the shape, size, or structural strength of the bottom plate itself, and not intended for welding to another bottom plate. The first side wall has a predetermined width W2, and the second side wall has a predetermined width W3, and 2W2 ≥ W3. With this setting, because the sum of the widths W2 of two adjacent first side walls is large, the width of the moltenable connection area between the two adjacent bottom plates is large during the welding process, the width of the welded structure formed between the two adjacent bottom plates after welding is large, the structural strength of the welded structure between the two adjacent bottom plates is high, the possibility of structural problems such as cracks, fractures, or bending occurring in the welded structure between the two adjacent bottom plates is low, and thus the operational reliability of the structural plate formed by welding at least two bottom plates is high.

[0007] Preferably, the dimensions satisfy 7mm ≤ W2 ≤ 10mm or 3mm ≤ W3 ≤ 8mm.

[0008] Preferably, the bottom plate further includes a second top wall and a second bottom wall, the second top wall being connected to the second bottom wall via a first side wall and a second side wall, the second top wall, the first side wall and the second bottom wall being at least part of a structure for forming a fourth cavity, the connection point of any first side wall away from an adjacent first side wall and the corresponding second top wall includes a first chamfer, and / or the connection point of any first side wall away from an adjacent first side wall and the corresponding second bottom wall includes a second chamfer.

[0009] Preferably, the first chamfered portion has a rounded chamfered structure, the first chamfered portion has a predetermined radius R1, and satisfies 1 mm ≤ R1 ≤ 3 mm, and / or the second chamfered portion has a rounded chamfered structure, the second chamfered portion has a predetermined radius R2, and satisfies 1 mm ≤ R2 ≤ 3 mm.

[0010] Preferably, the second top wall has a predetermined height H2 relative to the second bottom wall, satisfying 5mm ≤ H2 ≤ 8mm.

[0011] Preferably, the bottom plate further includes a support located within the fourth cavity, and the second bottom wall is connected to the second top wall via the support.

[0012] Preferably, the support portion has a predetermined height H3 and satisfies 5mm ≤ H3 ≤ 8mm, and / or the support portion has a predetermined width W4 and satisfies 3mm ≤ W4 ≤ 5mm.

[0013] Preferably, the connection point between the support portion and the second top wall includes a third chamfered portion, and / or the connection point between the support portion and the second bottom wall includes a fourth chamfered portion.

[0014] Preferably, the third chamfered portion has a rounded chamfered structure, the third chamfered portion has a predetermined radius R3, and satisfies 1 mm ≤ R3 ≤ 3 mm, and / or the fourth chamfered portion has a rounded chamfered structure, the fourth chamfered portion has a predetermined radius R4, and satisfies 1 mm ≤ R4 ≤ 3 mm.

[0015] Preferably, the support portion has a plate-like structure, and the fourth cavity is partitioned by the support portion, thereby forming at least two parallel and communicating flow channels.

[0016] Preferably, the cross-sectional shape of the flow path is rectangular, circular, semicircular, elliptical, or hexagonal.

[0017] Preferably, the bottom plate further includes at least two separators located within the same flow path, the separators being parallel to the plate-shaped support, and each separator located within the same flow path being spaced apart along the flow direction of the flow path.

[0018] Preferably, each bottom plate is provided so as to be distributed along the width or length of the battery case, the fourth cavities of each bottom plate are in communication with each other, one outermost bottom plate is provided with an inlet, and the other outermost bottom plate is provided with an outlet.

[0019] Preferably, the battery case further comprises an inlet connection tube and an outlet connection tube, the inside of which the inlet connection tube communicates with an inlet port and is sealed to a bottom plate on which the inlet port is provided, the inside of the outlet connection tube communicates with an outlet port and is sealed to a bottom plate on which the outlet port is provided, and the inlet connection tube and the outlet connection tube are used to communicate with corresponding external guide tubes.

[0020] Preferably, the bottom plate is provided with a fifth opening that communicates with a fourth cavity, and the battery case further comprises a first closing member that closes the fifth opening.

[0021] Preferably, the battery case further comprises side plates, each bottom plate being distributed along the width or length of the battery case, the outermost bottom plate being integrally molded or welded to the side plate, the side plate being provided with an inwardly recessed slide groove, the slide groove being used for sliding engagement with a slide rail, the side wall of the side plate being formed surrounding the slide groove being provided with a hanging hole, the hanging hole being drilled by a hook so that the side plate is connected to the hook.

[0022] The side plate of the battery case of the present invention may be provided with an inwardly recessed sliding groove, and the fixing device for housing the battery case may include a sliding rail, and the sliding groove may slide-fit with the sliding rail. This assembly method makes it easy to quickly attach the battery case to the fixing device by sliding, resulting in high assembly efficiency. Of course, this assembly method also makes it easy to quickly detach the battery case from the fixing device by sliding, resulting in high removal efficiency. The side plate of the battery case is further provided with a suspension hole. The suspension hole is drilled by a hook of a lifting device (e.g., a crane, overhead vehicle, or other device), thereby connecting the side plate to the hook. This allows the hook of the lifting device to quickly move the battery case. For example, the hook may move the battery case to a position where the sliding groove and the sliding rail are aligned in order to slide-fit the sliding groove and the sliding rail. Alternatively, the hook may move the battery case to another position away from the fixing device. Since the suspension holes are provided in the side wall that surrounds the slide groove in the side plate, this installation results in a high degree of structural compactness between the slide groove and the suspension holes. Under the condition that the size of the structure for installing the slide groove and suspension holes in the side plate is small and the size along other directions is the same, the volume of the side plate is small, the space occupied by the battery case in the fixing device is small, and many battery cases can be accommodated in the space of the fixing device, resulting in a high load capacity. Accordingly, the weight of the side plate is light, and the energy consumption for transporting the battery cases is also low.

[0023] Preferably, a sliding groove is provided in the outer wall of the side plate, which is provided along the height direction of the battery case, and a hanging hole is provided in the top wall of the side plate, which is formed to surround the sliding groove.

[0024] Preferably, a first cavity is further provided at the top of the side plate, the first cavity is in communication with a slide groove via a hanging hole, and the first cavity is used to accommodate at least a portion of the hook.

[0025] Preferably, on the side of the side plate away from the slide groove, a second cavity is further provided. The side plate is provided with a first opening, the first opening communicates with the suspension hole, the second cavity communicates with the slide groove through the first opening, and the second cavity communicates with the first cavity through the first opening.

[0026] Preferably, at the bottom of the side plate, a third cavity is further provided. The side plate is provided with a second opening, the second opening communicates with the first opening, the second opening also communicates with the slide groove, the third cavity communicates with the second cavity through the second opening, and the third cavity communicates with the slide groove through the second opening.

[0027] Preferably, a third opening is provided on the outer wall of the side plate, the third opening communicates with the second opening, and the third opening is used for the hook to retreat from the outer arc surface of the bent portion.

[0028] Preferably, the side plate includes an I-shaped rib portion, and the first cavity, the second cavity, the third cavity and the slide groove are formed by being partitioned by the I-shaped rib portion. The suspension hole, the first opening and the second opening are provided on the I-shaped rib portion.

[0029] Preferably, a fourth opening is provided on the outer wall of the side plate, the fourth opening communicates with the suspension hole, and the fourth opening is used for the hook to retreat from the inner arc surface of the bent portion.

[0030] Preferably, the slide groove has a predetermined width W1, satisfying 10 mm ≤ W1 ≤ 15 mm, and / or the slide groove has a predetermined depth H1, satisfying 8 mm ≤ H1 ≤ 12 mm.

[0031] The second aspect of the present invention provides a method for manufacturing a battery case. The manufacturing method includes step S1 of manufacturing a side plate and a bottom plate connected to each other by an integral molding process, and step S2 of welding at least two bottom plates by a friction welding process.

Effect of the Invention

[0032] The outermost bottom plate and side plates, which are connected to each other, are manufactured by an integral molding process. This integral molding process has the advantage of reducing the number of molds to be manufactured, increasing production efficiency, and improving the structural strength and dimensional accuracy between the outermost bottom plate and side plates. The integral molding process may be a casting process, an extrusion process, or an injection molding process. The first side walls of at least two bottom plates are welded by a friction welding process. More specifically, the temperature of the first side walls of the bottom plates is increased by high-speed friction until at least a portion of the first side walls is melted, then the molten portions of the first side walls of the two bottom plates are welded together, and after the first side walls have cooled, a welded structure is formed between the first side walls of the two bottom plates. Since auxiliary welding with other materials is not required in this welding process, the material of the welded structure between the first side walls of the two bottom plates is the same as the material of the bottom plate, meaning that the structural strength of the welded structure between the first side walls of the two bottom plates is the same as the structural strength of the bottom plate, and the operational reliability of the formed structural plate located at the bottom of the battery case is high. Here, the first side walls of the two base plates can be rubbed against each other at high speed until at least a portion of the first side walls of the two base plates melts, or the first side walls of the two base plates can be rubbed simultaneously using the curved side wall of the high-speed rotating column, and the molten portions of the first side walls of the two base plates can be welded together.

[0033] To more clearly explain the technical solutions of the embodiments of the present invention, the drawings necessary for use in the embodiments are briefly introduced below. Clearly, the drawings referred to in the following description are only a few embodiments of the present invention, and those skilled in the art can obtain other drawings based on these without expending any effort commensurate with inventive step. [Brief explanation of the drawing]

[0034] [Figure 1] This is a schematic diagram of the three-dimensional structure in one specific embodiment of the battery case according to the present invention. [Figure 2] Figure 1 is a schematic diagram of the battery case structure after disassembly. [Figure 3] This is a localized, enlarged schematic diagram of area A in Figure 2. [Figure 4] This is a schematic diagram of the structure of the base plate and side plate. [Figure 5] This is a localized, enlarged schematic diagram of section B in Figure 4. [Figure 6] This is a schematic diagram of the structure in one specific embodiment of the hook. [Figure 7] This is a cross-sectional view along the C-C direction between the bottom plate and the side plate in Figure 2. [Figure 8] This is a localized, enlarged schematic diagram of area D in Figure 7. [Figure 9] Figure 8 is a schematic diagram of the structure of the I-shaped rib section. [Figure 10] This is a schematic diagram of the structure of section E in Figure 7. [Figure 11] Figure 2 is a cross-sectional view along the F-F direction between the bottom plate, the first closing member, and the second closing member. [Figure 12] This is a schematic diagram of the structure of the two base plates. [Figure 13] This is a schematic diagram of the three base plates in a disassembled structure. [Figure 14] This is a localized, enlarged schematic diagram of section G in Figure 12. [Figure 15] This is a schematic diagram of the structure in one specific embodiment of the first closure member. [Figure 16] This is a schematic diagram of the structure in another specific embodiment of the first closure member. [Figure 17] This is a localized, enlarged schematic diagram of section H in Figure 12. [Figure 18] This is a schematic diagram of the structure in one specific embodiment of the second closure member. [Figure 19] This is a flowchart of one specific embodiment of the method for manufacturing a battery case according to the present invention. [Modes for carrying out the invention]

[0035] To better understand the solution provided by the present invention, embodiments of the present invention will be described in detail below with reference to the drawings.

[0036] As is clear, the embodiments described represent only some, and not all, embodiments of the present invention. All other embodiments that a person skilled in the art could obtain based on the embodiments of the present invention without performing work worthy of inventive step are all within the scope of the protection of the present invention.

[0037] The terms used in the embodiments of the present invention are for the sole purpose of describing specific embodiments and are not intended to limit the invention. The singular forms of “one type,” “the said,” and “the said” used in the embodiments of the present invention and the appended claims are also intended to include plural forms unless the context clearly indicates otherwise.

[0038] It is important to understand that the terms "and / or" used herein simply describe a relationship that explains the related objects, and that there may be three types of relationships. For example, A and / or B can indicate three situations: A existing alone, A and B existing simultaneously, or B existing alone. Also, the symbol " / " in this specification generally indicates that the related objects before and after are in an "or" relationship.

[0039] As shown in Figure 1, a first embodiment of the present invention provides a battery case 10. The inside of the battery case houses a battery (not shown), and the battery case protects the battery. In actual applications, the battery case may be housed in a fixing device such as a holder, box, or cabinet. As shown in Figure 2, the battery case 10 comprises a side plate 1, a bottom plate 2, a front plate 3, a rear plate 4, and a top lid 5. Two side plates 1 are connected to the bottom plate 2 and are arranged facing each other, the front plate 3 is connected to the bottom plate 2, the rear plate 4 is connected to the bottom plate 2 and is arranged facing each other, and at least two of the side plates 1, the front plate 3, and the rear plate 4 are connected to the top lid 5, and the side plates 1, the bottom plate 2, the front plate 3, the rear plate 4, and the top lid 5 form a space for housing a battery. The following description in this specification will first introduce the structure of the side plate 1, and then the structure of the bottom plate 2. The directions X, Y, and Z described herein are perpendicular to each other in pairs, and the dashed lines in the drawings of this application represent structural boundaries.

[0040] As shown in Figure 3, the side plate 1 is provided with an inwardly recessed slide groove 11, which slides into a slide rail (not shown). As shown in Figures 4 and 5, a hanging hole 12 is provided in the side wall of the side plate 1 that surrounds the slide groove 11, and the side plate 1 is connected to the hook 20 by drilling the hanging hole 12 with a hook 20 as shown in Figure 6.

[0041] As shown in Figure 3, the side plate 1 of the battery case 10 may be provided with an inwardly recessed slide groove 11, and the fixing device (not shown) for housing the battery case 10 may include a slide rail, and the slide groove 11 may slide-fit with the slide rail. This assembly method makes it easy to quickly attach the battery case 10 to the fixing device by sliding, resulting in high assembly efficiency. Of course, this assembly method also makes it easy to quickly detach the battery case 10 from the fixing device by sliding, resulting in high removal efficiency. As shown in Figures 4 and 5, the side plate 1 of the battery case 10 is further provided with a suspension hole 12. The suspension hole 12 is drilled by a hook 20 (shown in Figure 6) of a lifting device (e.g., a crane, overhead vehicle, or other device), thereby connecting the side plate 1 to the hook 20. This allows the hook 20 of the lifting device to quickly move the battery case 10. For example, the hook 20 may move the battery case 10 to a position where the slide groove 11 and the slide rail are aligned in order to slide-fit the slide groove 11 and the slide rail. Alternatively, the hook 20 may move the battery case 10 to another position away from the fixing device. Since the hanging hole 12 is provided in the side wall that surrounds the slide groove 11 in the side plate 1, this installation results in a high degree of structural compactness between the slide groove 11 and the hanging hole 12. Under the condition that the size of the structure for installing the slide groove 11 and the hanging hole 12 in the side plate 1 (e.g., the size along direction X) is small and the size along other directions (e.g., directions Z and Y) is the same, the volume of the side plate 1 is small, the space occupied by the battery case 10 in the fixing device is small, and many battery cases 10 can be accommodated in the space of the fixing device, resulting in a high loading rate. Accordingly, the weight of the side plate 1 is light, and the energy consumption for transporting the battery cases 10 is also low.

[0042] Here, as shown in Figure 4, the slide groove 11 may be provided along the length direction of the side plate 1 (a direction parallel to direction Y).

[0043] Furthermore, as shown in Figures 7 and 8, the shape of the cross-section perpendicular to the direction Y of the slide groove 11 may be a rectangle or a polygon such as an isosceles trapezoid.

[0044] Furthermore, in the embodiments of the present invention, the shape and number of suspension holes 12 are not limited.

[0045] As shown in Figure 8, the slide groove 11 is provided on the outer wall 1a of the side plate 1, which is installed along the height direction (parallel to direction X) of the battery case 10. Accordingly, the slide rail of the fixing device (not shown) is also provided on the side wall structure of the fixing device, which is installed along the height direction (parallel to direction X) of the fixing device. This installation simplifies the structure of the fixing device for sliding and fitting with the battery case 10. Since the outer wall 1a is part of the structure of the battery case 10 from a general viewing angle, the slide groove 11 is easily visible to the user, thereby making it easy for the user to quickly and accurately slide and fit the slide groove 11 and the slide rail. For similar reasons, the hanging hole 12 is also easily visible to the user, thereby making it easy for the user to quickly and accurately drill the hanging hole 12 for the hook 20. Therefore, the above structural installation can improve the assembly efficiency and assembly accuracy of the battery case 10. The hanging hole 12 is provided in the top wall 111 of the side plate 1, which surrounds the slide groove 11. Due to the force of gravity from the battery case 10, the hook 20 is unlikely to detach from the hanging hole 12, thus ensuring high reliability of the connection between the battery case 10 and the hook 20.

[0046] In other embodiments (not shown), the bottom wall of the side plate 1 may be provided with a sliding groove 11 and a hanging hole 12. The following description in this specification mainly uses the example that the sliding groove 11 and the hanging hole 12 are provided on the outer wall 1a of the side plate 1.

[0047] As optional, as shown in Figure 8, a first cavity 13 is further provided at the top 1b of the side plate 1, the first cavity 13 is in communication with the slide groove 11 via the hanging hole 12, and the first cavity 13 accommodates at least a portion of the hook 20.

[0048] A portion of the structure of the hook 20 shown in Figure 6 may be moved into the first cavity 13 via the slide groove 11 and hanging hole 12 shown in Figure 8, thereby connecting the hook 20 to the side plate 1. With this installation, the space for the structure of the part of the side plate 1 that houses the hook 20 is large, there are many points in the internal structure of the side plate 1 for connecting to the hook 20, the area of ​​connection with the hook 20 in the internal structure of the side plate 1 is large, the points of connection with the hook 20 in the internal structure of the side plate 1 are located close to the inside of the side plate 1, and accordingly the length or volume of the structure of the hook 20 located inside the side plate 1 may be increased, the structural strength of the hook 20 is large, and the reliability of the connection between the side plate 1 and the hook 20 is high. With the installation of the first cavity 13, the weight 1 of the battery case 10 is lighter, and the energy consumption for transporting the battery case 10 is also reduced.

[0049] As shown in Figure 8, the first cavity 13 may be provided along the length direction of the side plate 1 (a direction parallel to direction Y).

[0050] Furthermore, as shown in Figure 8, the shape of the cross-section perpendicular to the direction Y of the first cavity 13 may be a polygon such as a rectangle.

[0051] As selectable, as shown in Figure 8, a second cavity 15 is further provided on the side of the side plate 1 away from the slide groove 11, and a first opening 14 is provided in the side plate 1, the first opening 14 is in communication with the hanging hole 12, the second cavity 15 is in communication with the slide groove 11 via the first opening 14, and the second cavity 15 is in communication with the first cavity 13 via the first opening 14.

[0052] A portion of the structure of the hook 20 shown in Figure 6 may be located within the first opening 14 and the second cavity 15 shown in Figure 8. This arrangement increases the space available within the side plate 1 to accommodate a portion of the structure of the hook 20, increases the number of connection points with the hook 20 in the internal structure of the side plate 1, and increases the area available for connection with the hook 20 in the internal structure of the side plate 1. Consequently, the length or volume of the structure within the hook 20 located within the side plate 1 increases, the structural strength of the hook 20 increases, and the reliability of the connection between the side plate 1 and the hook 20 increases. The installation of the second cavity 15 reduces the weight 1 of the battery case 10 and also reduces the energy consumption required to transport the battery case 10.

[0053] As shown in Figure 8, the second cavity 15 may be provided along the length direction of the side plate 1 (a direction parallel to direction Y).

[0054] Furthermore, as shown in Figure 8, the shape of the cross-section of the second cavity 15 perpendicular to the direction Y may be a polygon such as a rectangle.

[0055] As selectable, as shown in Figure 8, a third cavity 17 is further provided at the bottom 1c of the side plate 1, and a second opening 16 is provided in the side plate 1, the second opening 16 is in communication with the first opening 14, the second opening 16 is in communication with the slide groove 11, the third cavity 17 is in communication with the second cavity 15 via the second opening 16, and the third cavity 17 is in communication with the slide groove 11 via the second opening 16.

[0056] A portion of the structure of the hook 20 shown in Figure 6 may be located within the second opening 16 and the third cavity 17 shown in Figure 8. This arrangement increases the space available within the side plate 1 to accommodate a portion of the structure of the hook 20, increases the number of connection points with the hook 20 in the internal structure of the side plate 1, and increases the area available for connection with the hook 20 in the internal structure of the side plate 1. Consequently, the length or volume of the structure within the hook 20 located within the side plate 1 increases, the structural strength of the hook 20 increases, and the reliability of the connection between the side plate 1 and the hook 20 increases. The installation of the third cavity 17 reduces the weight 1 of the battery case 10 and also reduces the energy consumption required to transport the battery case 10.

[0057] As shown in Figure 8, the third cavity 17 may be provided along the length direction of the side plate 1 (a direction parallel to direction Y).

[0058] Furthermore, as shown in Figure 8, the shape of the cross-section of the third cavity 17 perpendicular to the direction Y may be a polygon such as a rectangle.

[0059] As selectable, as shown in Figure 8, a third opening 18 is provided in the outer wall 1a of the side plate 1, the third opening 18 communicates with the second opening 16, and the third opening 18 is used to retract from the outer curved surface 201 of the bent portion of the hook 20 shown in Figure 6.

[0060] At least a portion of the outer curved surface 201 of the bent portion of the hook 20 shown in Figure 6 is movable through the third opening 18 shown in Figure 8 to the slide groove 11 or other internal space of the side plate 1, thereby facilitating the connection of a portion of the hook 20's structure to the internal structure of the side plate 1. The installation of the third opening 18 reduces the possibility of the hook 20 becoming stuck to the structure of the side plate 1 during connection, and makes it easier for the user to quickly connect the hook 20 to the side plate 1.

[0061] As shown in Figure 5, the surface of the outer wall 1a of the side plate 1 that surrounds the third opening 18 includes a first rounded chamfer structure 181. The installation of the first rounded chamfer structure 181 reduces the degree of stress concentration in the structure forming the third opening 18 within the side wall 1. Therefore, the possibility of crack problems occurring in the structure forming the third opening 18 within the side plate 1 is low.

[0062] Furthermore, in the embodiments of the present invention, the shape and area of ​​the third opening 18 are not limited.

[0063] As shown in Figure 8, the side plate 1 is partitioned by including an I-shaped rib portion 1d to form a first cavity 13, a second cavity 15, a third cavity 17, and a slide groove 11. This configuration makes the side plate 1 lighter in weight, increases its structural strength, and reduces the likelihood of structural problems such as bending deformation occurring in the side plate 1. The suspension holes 12, the first opening 14, and the second opening 16 are provided in the I-shaped rib portion 1d, creating a configuration in which the slide groove 11, the suspension holes 12, the first cavity 13, the first opening 14, the second cavity 15, the second opening 16, and the third cavity 17 communicate with each other. Thus, some parts of the hook 20 structure can be positioned within the slide groove 11, the hanging hole 12, the first cavity 13, the first opening 14, the second cavity 15, the second opening 16, and the third cavity 17, respectively, thereby achieving a technical effect of improving the reliability of the connection between the side plate 1 and the hook 20 as described above. This will not be repeated here.

[0064] As shown in Figure 8, a portion of the first opening 14 is provided in a structure located between the first cavity 13 and the second cavity 15 of the side plate 1, and the other portion of the first opening 14 is provided in a structure located between the second cavity 15 and the slide groove 11 of the side plate 1.

[0065] Furthermore, as shown in Figure 9, the I-shaped rib portion 1d includes a first top wall 111, an inner wall 112, and a first bottom wall 113 to surround the slide groove 11. The first top wall 111 separates the slide groove 11 from the first cavity 13, the inner wall 112 separates the slide groove 11 from the second cavity 15, and the first bottom wall 113 separates the slide groove 11 from the third cavity 17.

[0066] As optional, as shown in Figure 8, a fourth opening 19 is provided in the outer wall 1a of the side plate 1, which communicates with the hanging hole 12 and is used to retract from the inner curved surface 202 of the bent portion of the hook 20 shown in Figure 6.

[0067] At least a portion of the inner arc surface 202 of the bent portion of the hook 20 shown in Figure 6 is movable through the fourth opening 19 shown in Figure 8 to the slide groove 11 or other internal space of the side plate 1, thereby facilitating the connection of a portion of the hook 20's structure to the internal structure of the side plate 1. The installation of the fourth opening 19 reduces the possibility of the hook 20 becoming stuck to the structure of the side plate 1 during connection, and makes it easier for the user to quickly connect the hook 20 to the side plate 1.

[0068] As shown in Figure 5, the surface formed around the fourth opening 19 on the outer wall 1a of the side plate 1 includes a second rounded chamfer structure 191. The installation of the second rounded chamfer structure 191 reduces the degree of stress concentration in the structure forming the fourth opening 19 within the side wall 1. Therefore, the possibility of crack problems occurring in the structure forming the fourth opening 19 within the side plate 1 is low.

[0069] The number of installations of the first opening 14, second opening 16, third opening 18, and fourth opening 19 is the same as the number of installations of the suspension holes 12. That is, the first opening 14, second opening 16, third opening 18, and fourth opening 19 exist in correspondence with each suspension hole 12.

[0070] As selectable, as shown in Figure 8, the slide groove 11 has a predetermined width W1 (size along direction X) satisfying 10 mm ≤ W1 ≤ 15 mm. Specifically, W1 may be 10 mm, 11 mm, 12 mm, 13 mm, 14 mm, or 15 mm.

[0071] As shown in Figure 8, when W1 is less than 10 mm, the width W1 of the slide groove 11 is small, and accordingly, the width of the slide rail of the fixing device (not shown) is also small, resulting in low structural strength of the slide rail and thus low reliability of the connection between the battery case 10 and the fixing device. When the width W1 of the slide groove 11 is greater than 15 mm, the width W1 of the slide groove 11 is large, the height of the side plate 1 (size along direction X) is large, the volume of the side plate 1 is large, and as a result, the space of the fixing device occupied by a single battery case 10 is large, the number of battery cases 10 that can be accommodated in the fixing device is small, i.e., the loading rate is low, the weight of the side plate 1 is heavy, and the energy consumption for transporting the battery cases 10 is also high. Therefore, it is desirable for the width W1 of the slide groove 11 to be between 10 mm and 15 mm.

[0072] As selectable, as shown in Figure 8, the slide groove 11 has a predetermined depth H1 (size along direction Z) and satisfies 8 mm ≤ H1 ≤ 12 mm, where H1 may specifically be 8 mm, 9 mm, 10 mm, 11 mm, or 12 mm.

[0073] As shown in Figure 8, when H1 is less than 8 mm, the depth H1 of the slide groove 11 is small, and there is less space in the slide groove 11 to accommodate the slide rail of the fixing device (not shown). This makes it easy for the slide rail to detach from the slide groove 11, and the sliding engagement between the slide groove 11 and the slide rail is easily lost, meaning that the connection between the battery case 10 and the fixing device is easily lost. When H2 is greater than 12 mm, the depth H1 of the slide groove 11 is large, the structural strength of the side plate 1 is low, and structural problems such as deformation of the side plate 1 are likely to occur. Therefore, it is desirable for the depth H1 of the slide groove 11 to be between 8 mm and 12 mm.

[0074] The following section of this specification describes the structure of the base plate 2.

[0075] As shown in Figure 2, a structural plate located at the bottom of the battery case 10 is used to fix and support a battery (not shown) located inside the battery case 10. This large structural plate is composed of at least two smaller bottom plates 2. As shown in Figures 10 to 11, a fourth cavity 21a is provided in each of the bottom plates 2, and the fourth cavity 21a is used for the circulation of a coolant (not shown). More specifically, the coolant located outside the battery case 10 flows into the fourth cavity 21a. Due to the method of heat conduction, the coolant can absorb the heat generated by the battery (not shown) located in the bottom plate 2 during operation. The coolant that has absorbed the heat can be re-flowed to the outside of the bottom plate 2. By circulating the coolant back and forth within the fourth cavity 21a, the battery is operated within the normal temperature range, improving the battery's lifespan. As can be seen from the above, the bottom plate 2 is used not only as part of the structural plate of the battery case 10 to have the function of fixing and supporting the battery, but the bottom plate 2 may also achieve heat dissipation by using the fourth cavity 21a provided inside the bottom plate 2 to circulate the coolant. Compared to separately installing a structural plate for fixing and supporting the battery and a heat dissipation plate for heat dissipation, the complexity of the structure of the bottom plate 2 and battery case 10 in the embodiment of the present invention is lower, and the difficulty of manufacturing the bottom plate 2 and battery case 10 is also lower. Next, since the bottom plate 2 in contact with the battery has an integrated heat dissipation function, the formed heat conduction path is short, and the heat from the battery can be quickly conducted to the coolant inside the bottom plate 2, resulting in high heat dissipation efficiency. Because the area of ​​the structural plate at the bottom of the battery case 10 is large, if a large area structural plate is manufactured directly at once using a conventional manufacturing process, the structural strength and dimensional accuracy of the formed structural plate will be relatively inferior. On the other hand, the structural plate at the bottom of the battery case 10 in the embodiment of the present invention is formed by welding together at least two bottom plates 2 with relatively small areas. With this setup, at least two relatively small base plates 2 may be manufactured first during the production process. The structural strength and dimensional accuracy of each base plate 2 manufactured using the existing manufacturing process are relatively high. Next, the formed base plates 2 may be welded together to form the base plate structural plate required for the battery case 10. The structural strength and dimensional accuracy of the formed structural plate are also relatively high.This allows for better meeting actual usage needs. Here, each bottom plate 2 includes a first side wall 22a, and the first side wall 22a of each bottom plate 2 is welded to the first side wall 22a of the adjacent bottom plate 2, i.e., the two welded first side walls 22a form a connecting structure between the two bottom plates 2. The welding method has the advantage of high strength and reliability of the connecting structure. As shown in Figure 8, the outermost bottom plate 2 further includes a second side wall 22b, which is a structure to satisfy the shape, size, or structural strength of the bottom plate 2 itself, and the second side wall 22b is not for welding to another bottom plate 2. The first side wall 22a has a predetermined width W2 (size along direction Z), and the second side wall 22b has a predetermined width W3 (size along direction Z), and satisfies 2W2 ≥ W3. With this setting, the sum of the widths W2 of the two adjacent first side walls 22a is large, so during the welding process, the width of the moltenable connection area between the two adjacent bottom plates 2 is large, the width of the welded structure formed between the two adjacent bottom plates 2 after welding is large, the structural strength of the welded structure between the two adjacent bottom plates 2 is high, the possibility of structural problems such as cracks, fractures or bending occurring in the welded structure between the two adjacent bottom plates 2 is low, and as a result the operational reliability of the structural plate formed by welding at least two bottom plates 2 is high.

[0076] As shown in Figure 12, when the structural plate at the bottom of the battery case 10 is composed of two bottom plates 2, each bottom plate 2 includes a first side wall 22a and a second side wall 22b that are spaced apart, the two first side walls 22a are welded together, the second side wall 22b is not used for welding, and the fourth cavity 21a is located between the first side wall 22a and the second side wall 22b. As shown in Figure 13, when the structural plate at the bottom of the battery case 10 is composed of at least three bottom plates 2, at least three bottom plates 2 are provided so as to be distributed along the width direction (parallel to direction Z) of the battery case 10. The outermost bottom plate 2 may include a first side wall 22a and a second side wall 22b spaced apart, and the corresponding fourth cavity 21a is located between the first side wall 22a and the second side wall 22b. The bottom plate 2 located between two bottom plates 2 includes two first side walls 22a spaced apart, and the corresponding fourth cavity 21a is located between the two first side walls 22a. The two first side walls 22a between two adjacent bottom plates 2 are welded, while the second side wall 22b is not used for welding.

[0077] In other embodiments (not shown), at least three bottom plates 2 are provided so as to be distributed along the length direction (parallel to direction Y) of the battery case 10.

[0078] Selectively, as shown in Figure 8, the dimensions satisfy 3mm ≤ W3 ≤ 8mm. The width W3 may specifically be 3mm, 4mm, 5mm, 6mm, 7mm, or 8mm.

[0079] As shown in Figure 8, when the width W3 of the second side wall 22b is less than 3 mm, the width of the second side wall 22b is too small, resulting in low structural strength and making it prone to structural problems such as cracking, fracture, or bending deformation. When the width W3 of the second side wall 22b is greater than 10 mm, the width of the second side wall 22b is too large, and under conditions where the size along the direction Z of a single base plate 2 is limited and the distance between the second side wall 22b and the first side wall 22a is limited, the size along the direction Z of the fourth cavity 21a is small, resulting in a small amount of coolant that can be contained in the fourth cavity 21a and poor heat dissipation efficiency. Therefore, it is desirable for the width W2 of the first side wall 22a to be between 3 mm and 8 mm.

[0080] Selectively, as shown in Figure 10, the condition 7mm ≤ W2 ≤ 10mm is satisfied. The width W2 may specifically be 7mm, 8mm, 9mm, or 10mm.

[0081] As shown in Figure 10, when the width W2 of the first side wall 22a is less than 7 mm, the width of the first side wall 22a is too small, resulting in a small width for a portion of the welded structure that forms the bottom plate 2. This leads to low structural strength in the formed welded structure and makes it prone to structural problems such as cracks, fractures, and bending deformation. When the width W2 of the first side wall 22a is greater than 10 mm, the width of the first side wall 22a is too large. Under conditions where the size of a single bottom plate 2 along the direction Z is limited, the size of the fourth cavity 21a along the direction Z is small, resulting in a small amount of coolant that can be contained in the fourth cavity 21a and poor heat dissipation efficiency. Therefore, it is desirable for the width W2 of the first side wall 22a to be between 7 mm and 10 mm.

[0082] As optional, as shown in Figure 10, the base plate 2 further includes a second top wall 23a and a second bottom wall 23b, the second top wall 23a being connected to the second bottom wall 23b via a first side wall 22a and a second side wall 22b, and the second top wall 23a, the first side wall 22a and the second bottom wall 23b are at least part of a structure for surrounding and forming the fourth cavity 21a. With this configuration, the structure of the base plate 2 is less complex and easier to manufacture.

[0083] The structural plate at the bottom of the battery case 10 is composed of two bottom plates 2, each bottom plate 2 further including a second side wall 22b spaced apart from a first side wall 22a, and the second top wall 23a is connected to the second bottom wall 23b via the second side wall 22b. The second top wall 23a, the first side wall 22a, the second bottom wall 23b, and the second side wall 22b form a structure that surrounds the fourth cavity 21a.

[0084] When the structural plate at the bottom of the battery case 10 is composed of at least three bottom plates 2, the outermost bottom plate 2 further includes a second side wall 22b spaced apart from a first side wall 22a, and the second top wall 23a is connected to the second bottom wall 23b via the second side wall 22b, and the second top wall 23a, the first side wall 22a, the second bottom wall 23b and the second side wall 22b form a structure for surrounding the corresponding fourth cavity 21a. The bottom plate 2 located between the two bottom plates 2 includes two first side walls 22a spaced apart, and the second top wall 23a is connected to the second bottom wall 23b via the two first side walls 22a spaced apart, and the first side wall 22a, the second bottom wall 23b and the two second side walls 22b form a structure for surrounding the corresponding fourth cavity 21a.

[0085] The second top wall 23a fixes and supports a battery (not shown). The battery case 10 may further include a thermally conductive adhesive provided between the second top wall 23a and the battery. The second top wall 23a is connected to the battery via the thermally conductive adhesive, which can quickly conduct heat from the battery to the second top wall 23a.

[0086] Furthermore, the material of the second top wall 23a may be metal. This results in higher thermal conductivity. The second top wall 23a can quickly conduct heat to the coolant located in the fourth cavity 21a.

[0087] Furthermore, the battery case may further include a heat-absorbing layer (not shown) provided on the side of the second top wall 23a that is spaced apart from the second bottom wall 23b. The material of the heat-absorbing layer may be a carbon-nitrogen co-permeable layer, a nitrogen-oxygen co-permeable layer, a carbon-oxygen co-permeable layer, or a carbon-nitrogen-oxygen co-permeable layer. Any of the above materials can also be used to make at least a portion of the heat-absorbing layer black or a dark color close to black. Compared to other colors (silver-white of stainless steel or aluminum), a heat-absorbing layer that is black or a dark color close to black has a higher efficiency in absorbing thermal radiation electromagnetic waves, and a larger frequency range of thermal radiation electromagnetic waves that can be absorbed by a heat-absorbing layer that is black or a dark color close to black. Therefore, the heat-absorbing layer can quickly and in large quantities absorb thermal radiation electromagnetic waves generated when the battery is operating. That is, the heat-absorbing layer quickly absorbs heat from the battery using the principle of thermal radiation, and the second top wall 23a in contact with the heat-absorbing layer conducts the heat absorbed by the heat-absorbing layer to the coolant located in the fourth cavity 21a.

[0088] As selectable, as shown in Figure 10, the connection point between the side of any first side wall 22a that is separated from an adjacent first side wall 22a and the corresponding second top wall 23a includes a first chamfer 221. By installing the first chamfer 221, the degree of stress concentration at the connection point between the first side wall 22a and the second top wall 23a can be reduced, thereby reducing the possibility of structural problems such as cracks, fractures, or deformation occurring at the connection point between the first side wall 22a and the second top wall 23a.

[0089] As selectable, as shown in Figure 10, the connection point between the side of any first side wall 22a that is separated from an adjacent first side wall 22a and the corresponding second bottom wall 23b includes a second chamfer 222. By installing the second chamfer 222, the degree of stress concentration at the connection point between the first side wall 22a and the second bottom wall 23b can be reduced, thereby reducing the possibility of structural problems such as cracks, fractures, or deformation occurring at the connection point between the first side wall 22a and the second bottom wall 23b.

[0090] As selectable, as shown in Figure 10, the first chamfered portion 221 has a rounded chamfered structure and has a predetermined radius R1 satisfying 1 mm ≤ R1 ≤ 3 mm. The radius R1 may specifically be 1 mm, 1.5 mm, 2 mm, 2.5 mm, or 3 mm.

[0091] As shown in Figure 10, when the radius R1 is less than 1 mm, the radius R1 of the first chamfer 221 is small. The stress concentration at the connection point between the first side wall 22a and the second top wall 23a is high, and structural problems such as cracks, fractures, or deformations are likely to occur at the connection point between the first side wall 22a and the second top wall 23a. On the other hand, under conditions where dimensional accuracy is guaranteed, it is difficult to manufacture the first chamfer 221 with a small radius R1. When the radius R1 is greater than 3 mm, the radius R1 of the first chamfer 221 is large, the volume of the connection point between the first side wall 22a and the second top wall 23a is large, and under conditions where the volume of a single bottom plate 2 is constant, the volume of the fourth cavity 21a is small, the amount of coolant that can be contained in the fourth cavity 21a is small, and the heat dissipation efficiency is poor. Therefore, it is desirable for the radius R1 to be between 1 mm and 3 mm.

[0092] In other embodiments (not shown), the first chamfered portion 221 may have a corner chamfered structure.

[0093] As selectable, as shown in Figure 10, the second chamfered portion 222 has a rounded chamfered structure and has a predetermined radius R2 satisfying 1 mm ≤ R2 ≤ 3 mm. The radius R2 may specifically be 1 mm, 1.5 mm, 2 mm, 2.5 mm, or 3 mm.

[0094] As shown in Figure 10, when the radius R2 is less than 1 mm, the radius R2 of the second chamfer 222 is small. The stress concentration at the connection point between the first side wall 22a and the second bottom wall 23b is high, and structural problems such as cracks, fractures, or deformations are likely to occur at the connection point between the first side wall 22a and the second bottom wall 23b. On the other hand, manufacturing the second chamfer 222 with a small radius R2 is difficult under conditions where dimensional accuracy is guaranteed. When the radius R2 is greater than 3 mm, the radius R2 of the second chamfer 222 is large, the volume of the connection point between the first side wall 22a and the second bottom wall 23b is large, and under the condition that the volume of a single bottom plate 2 is constant, the volume of the fourth cavity 21a is small, the amount of coolant that can be contained in the fourth cavity 21a is small, and the heat dissipation efficiency is poor. Therefore, it is desirable for the radius R2 to be between 1 mm and 3 mm.

[0095] In other embodiments (not shown), the second chamfered portion 222 may have a corner chamfered structure.

[0096] Selectively, as shown in Figure 10, the second top wall 23a has a predetermined height H2 relative to the second bottom wall 23b, satisfying 5mm ≤ H2 ≤ 8mm. The height H2 may specifically be 5mm, 5.5mm, 6mm, 6.5mm, 7mm, 7.5mm, or 8mm.

[0097] As shown in Figure 10, when the height H2 is less than 5 mm, the height of the fourth cavity 21a located between the second top wall 23a and the second bottom wall 23b is small, the amount of coolant that can be contained in the fourth cavity 21a is small, and the heat dissipation efficiency is poor. When the height H2 is greater than 8 mm, the thickness of the bottom plate 2 is large, the weight of the battery case 10 is heavy, and the energy consumption for transporting the battery case 10 is large. Therefore, it is desirable for the height H2 to be between 5 mm and 8 mm.

[0098] As optional, as shown in Figure 10, the bottom plate 2 further includes a support portion 22c located within the fourth cavity 21a, and the second bottom wall 23b is connected to the second top wall 23a via the support portion 22c. With this configuration, the support portion 22c plays a role in improving the structural strength of the bottom plate 2, and the possibility of structural problems such as bending deformation, cracking, or fracture occurring in the second top wall 23a and the second bottom wall 23b is low.

[0099] The support portion 22c may be in the shape of a rod, column, plate, or disc. In the description below, the plate-shaped support portion 22c will be described mainly as an example. In the embodiments of the present invention, the number of support portions 22c installed is not limited.

[0100] Selectively, as shown in Figure 10, the support portion 22c has a predetermined height H3 (size parallel to direction X) and satisfies 5mm ≤ H3 ≤ 8mm. The height H3 may specifically be 5mm, 5.5mm, 6mm, 6.5mm, 7mm, 7.5mm, or 8mm.

[0101] As shown in Figure 10, the height H2 of the second top wall 23a relative to the second bottom wall 23b and the height H3 of the support portion 22c are the same. The technical effects of setting the numerical range for height H3 include the technical effects of setting the numerical range for height H2 as described above, and will not be explained again here.

[0102] As selectable, as shown in Figure 10, the support portion 22c has a predetermined width W4 (size parallel to direction Z) satisfying 3mm ≤ W4 ≤ 5mm. The width W4 may specifically be 3mm, 3.5mm, 4mm, 4.5mm, or 5mm.

[0103] As shown in Figure 10, when the width W4 of the support portion 22c is less than 3 mm, the structural strength of the support portion 22c is low, the effect of the support portion 22c on improving the structural strength of the bottom plate 2 is weak, and there is a high possibility that structural problems such as bending deformation, cracking, or fracture will occur in the second top wall 23a and the second bottom wall 23b. When the width W4 of the support portion 22c is greater than 5 mm, the space occupied by the support portion 22c in the fourth cavity 21a is large, the amount of coolant that can be contained in the fourth cavity 21a is small, and the heat dissipation efficiency is poor. Therefore, it is desirable for the width W4 of the support portion 22c to be between 3 mm and 5 mm.

[0104] As optional, as shown in Figure 10, the connection point between the support portion 22c and the second top wall 23a includes a third chamfer portion 223. By installing the third chamfer portion 223, the degree of stress concentration at the connection point between the support portion 22c and the second top wall 23a can be reduced, thereby reducing the possibility of structural problems such as cracks, fractures, or deformation occurring at the connection point between the support portion 22c and the second top wall 23a.

[0105] As optional, as shown in Figure 10, the connection point between the support portion 22c and the second bottom wall 23b includes a fourth chamfer portion 224. By installing the fourth chamfer portion 224, the degree of stress concentration at the connection point between the support portion 22c and the second bottom wall 23b can be reduced, thereby reducing the possibility of structural problems such as cracks, fractures, or deformation occurring at the connection point between the support portion 22c and the second bottom wall 23b.

[0106] As selectable, as shown in Figure 10, the third chamfered portion 223 has a rounded chamfered structure and has a predetermined radius R3 satisfying 1 mm ≤ R3 ≤ 3 mm. The radius R3 may specifically be 1 mm, 1.5 mm, 2 mm, 2.5 mm, or 3 mm.

[0107] As shown in Figure 10, when the radius R3 is less than 1 mm, the radius R3 of the third chamfer 223 is small, the stress concentration at the connection point between the support 22c and the second top wall 23a is high, and structural problems such as cracks, fractures, or deformations are likely to occur at the connection point between the support 22c and the second top wall 23a. On the other hand, manufacturing the third chamfer 223 with a small radius R3 is difficult under conditions where dimensional accuracy is guaranteed. When the radius R3 is greater than 3 mm, the radius R3 of the third chamfer 223 is large, the volume of the connection point between the support 22c and the second top wall 23a is large, and under the condition that the volume of a single bottom plate 2 is constant, the volume of the fourth cavity 21a is small, the amount of coolant that can be contained in the fourth cavity 21a is small, and the heat dissipation efficiency is poor. Therefore, it is desirable for the radius R3 to be between 1 mm and 3 mm.

[0108] In other embodiments (not shown), the third chamfered portion 223 has a corner chamfered structure.

[0109] As selectable, as shown in Figure 10, the fourth chamfer 224 has a rounded chamfer structure and has a predetermined radius R4 satisfying 1 mm ≤ R4 ≤ 3 mm. The radius R4 may specifically be 1 mm, 1.5 mm, 2 mm, 2.5 mm, or 3 mm.

[0110] As shown in Figure 10, when the radius R4 is less than 1 mm, the radius R4 of the fourth chamfer 224 is small, the stress concentration at the connection point between the support 22c and the second bottom wall 23b is high, and structural problems such as cracks, fractures, or deformations are likely to occur at the connection point between the support 22c and the second bottom wall 23b. On the other hand, manufacturing the fourth chamfer 224 with a small radius R4 is difficult under conditions where dimensional accuracy is guaranteed. When the radius R4 is greater than 3 mm, the radius R4 of the fourth chamfer 224 is large, the volume of the connection point between the support 22c and the second bottom wall 23b is large, and under the condition that the volume of a single bottom plate 2 is constant, the volume of the fourth cavity 21a is small, the amount of coolant that can be contained in the fourth cavity 21a is small, and the heat dissipation efficiency is poor. Therefore, it is desirable for the radius R4 to be between 1 mm and 3 mm.

[0111] In other embodiments (not shown), the fourth chamfered portion 224 has a corner chamfered structure.

[0112] As selectable, as shown in Figure 11, the support portion 22c is a plate-like structure, and the fourth cavity 21a is partitioned by the support portion 22c to form at least two parallel and communicating flow paths 211. With this configuration, the flow paths 211 are used to guide the coolant to flow regularly along the direction of extension of the flow paths 211 (a direction parallel to direction Y), thereby improving the efficiency of coolant flow. Furthermore, the flow paths 211 are used to divide the coolant and form at least two flowing fluid paths, each fluid absorbing heat from the corresponding portion in the bottom plate 2, and the difference in efficiency of heat transfer from each portion in the bottom plate 2 to the coolant is small. Therefore, the installation of the flow paths 211 can improve heat dissipation efficiency.

[0113] The more support portions 22c there are, the more flow channels 211 will be formed.

[0114] The cross-sectional shape of the flow path 211 can be selected from rectangular (as shown in Figure 10), circular, semicircular, elliptical, or hexagonal. Any of the above cross-sectional shapes of the flow path 211 can meet the requirements for the flow of coolant.

[0115] Selectively, as shown in Figure 11, the bottom plate 2 further includes at least two separators 22d located within the same flow path 211, the separators 22d being parallel to the plate-shaped support portion 22c, and each separator 22d located within the same flow path 211 being spaced apart along the flow direction of the flow path 211 (a direction parallel to direction Y).

[0116] As shown in Figure 11, as the coolant flows through the channel 211, multiple stacked flat flow layers, arranged along the flow direction of the channel 211, are easily formed. The flat flow layer in the coolant near the support portion 22c easily absorbs heat from the support portion 22c, and the flat flow layer in the coolant near the second top wall 23a easily absorbs heat from the second top wall 23a. However, the heat conduction efficiency between each flat flow layer is poor, making it difficult for heat to be transferred to the internal flat flow layer in the coolant, resulting in poor heat dissipation efficiency. However, by providing two adjacent separators 22d with a gap between them, the coolant easily forms turbulence in the space between the two adjacent separators 22d. This turbulence can break through the flat flow layer of the coolant and redistribute heat within the coolant, meaning that heat from outside the coolant is more easily transferred into the coolant, thereby improving heat dissipation efficiency.

[0117] The height of the separator 22d may be less than the height H2 of the fourth cavity 21a or the height H3 of the support portion 22c. The separator 22d may be connected only to the second top wall 23a, or the separator 22d may be connected only to the second bottom wall 23b. The height of the separator 22d may be equal to the height H2 of the fourth cavity 21a or the height H3 of the support portion 22c. For example, the separator 22d is connected not only to the second top wall 23a but also to the second bottom wall 23b. The width of the separator 22d (size along direction Z) is smaller than the width of the flow path 211 (size along direction Z), and the ratio of the width of the separator 22d to the width of the flow path 211 is in the range of 1:10 to 2:10. The length of the separator 22d (size along the direction Y) is smaller than the length of the support part 22c (size along the direction Y), and the ratio of the length of the separator 22d to the length of the support part 22c is in the range of 1:20 to 2:20.

[0118] Furthermore, the position of the separator 22d along direction Z and the position along direction Y within the flow path 211 are not restricted.

[0119] As selectable, as shown in Figure 12, each bottom plate 2 is provided so as to be distributed along the width direction (parallel to direction Z) of the battery case 10, and the fourth cavities 21a of each bottom plate 2 are in communication with each other, with an inlet 24a provided in one outermost bottom plate 2 and an outlet 24b provided in the other outermost bottom plate 2. With this arrangement, the coolant outside the bottom plate 2 can flow into the corresponding fourth cavity 21a of the bottom plate 2 from the inlet 24a of one outermost bottom plate 2, and the fourth cavities 21a of each bottom plate 2 are in communication in sequence, forming a single cooling path that guides the coolant and causes it to flow in one direction. The coolant may pass through each fourth cavity 21a in sequence, or the coolant may flow out of the bottom plate 2 from the fourth cavity 21a of the other outermost bottom plate 2 via the corresponding outlet 24b. With the above setup, the coolant flows in one direction from the inlet 24a to the outlet 24b, making it easier to control the flow of the coolant.

[0120] As shown in Figures 11 and 14, each bottom plate 2 is provided with a sixth opening 25b that communicates with the fourth cavity 21a, and the sixth openings 25b of two adjacent and welded bottom plates 2 communicate with each other. That is, the coolant located in the fourth cavity 21a of one bottom plate 2 can flow into the fourth cavity 21a of the other bottom plate 2 via the sixth opening 25b. The second top wall 23a, the first side wall 22a, and the second bottom wall 23b are formed surrounding the sixth opening 25b.

[0121] In other embodiments (not shown), each bottom plate 2 may be arranged so as to be distributed along the length direction (parallel to direction Y) of the battery case 10.

[0122] As optional, as shown in Figure 2, the battery case 10 further comprises an inlet pipe 6, the inside of which communicates with the inlet port 24a shown in Figure 12, and the inlet pipe 6 is used to communicate with a corresponding external guide pipe (not shown). With this setup, the coolant can flow from the external guide pipe through the inlet pipe 6 and the inlet port 24a in sequence into the fourth cavity 21a of the bottom plate 2. The inlet pipe 6 is sealed to the bottom plate 2 where the inlet port 24a is provided (for example, by welding or sealing using sealant) to reduce the possibility of coolant leakage between the inlet pipe 6 and the bottom plate 2.

[0123] As optional, as shown in Figure 2, the battery case 10 further comprises a liquid outlet connecting pipe 7, the inside of which communicates with the liquid outlet 24b shown in Figure 12, and the liquid outlet connecting pipe 7 is used to communicate with a corresponding external guide pipe (not shown). With this setup, the coolant can flow from the fourth cavity 21a of the bottom plate 2 through the liquid outlet 24b and the liquid outlet connecting pipe 7 in sequence into the corresponding external guide pipe. The liquid outlet connecting pipe 7 is sealed to the bottom plate 2 where the liquid outlet 24b is provided (for example, by welding or sealing using sealant) to reduce the possibility of coolant leakage between the liquid outlet connecting pipe 7 and the bottom plate 2.

[0124] As optional, as shown in Figure 14, the bottom plate 2 is provided with a fifth opening 25a that communicates with the fourth cavity 21a, which facilitates the manufacture of the bottom plate 2 having the fifth opening 25a and the fourth cavity 21a by an extrusion molding process. As shown in Figures 15-16, the battery case 10 may further include a first sealing member 8. The first sealing member 8 is used to seal the fifth opening 25a and has a sealing effect on the coolant located in the fourth cavity 21a, reducing the possibility of the coolant leaking out of the bottom plate 2 through the fifth opening 25a.

[0125] The first closing member 8 may be welded to the bottom plate 2 or bonded with sealant.

[0126] Furthermore, a fifth opening 25a is provided at both ends of the bottom plate 2 along the direction X, and the battery case 10 includes two first closing members 8, each of which closes the corresponding fifth opening 25a.

[0127] Furthermore, as shown in Figures 15 and 16, the first closing member 8 includes at least two projections 81 spaced apart along the direction Z, and the projections 81 close off the fifth opening 25a by drilling it. The height of the projections 81 along the direction X is the same as the height H2 of the fourth cavity 21a along the direction X.

[0128] As shown in Figures 15 and 16, a spacing space 82 is provided between each pair of protrusions 81. In the embodiment of the present invention, the number of protrusions 81 and spacing spaces 82 is not limited. There are spacing spaces 82 that are fitted into the support portion 22c and connect some of the support portion 22c to some of the protrusions 81, and there are also spacing spaces 82 that are fitted into the first side wall 22a and connect some of the first side wall 22a to some of the protrusions 81. The above arrangement further improves the reliability of the connection between the first closing member 8 and the bottom plate 2. Furthermore, each first closing member 8 is connected to at least two bottom plates 2, further improving the structural strength of the structural plate consisting of at least two bottom plates 2.

[0129] Of the fifth openings 25a, some communicate with the sixth opening 25b, and accordingly, there are projections 81 that drill into the sixth opening 25b, but the sixth opening 25b is not closed by the projections 81.

[0130] Optionally, as shown in Figure 8, the outermost bottom plate 2 may further include a third side wall 22e spaced apart from the second side wall 22b. That is, the second side wall 22b is located between the first side wall 22a and the third side wall 22e, and the second top wall 23a is also connected to the second bottom wall 23b via the third side wall 22e. The second top wall 23a, the third side wall 22e, the second bottom wall 23b, and the second side wall 22b form a fifth cavity 21b located within the outermost bottom plate 2. This configuration reduces the weight of the outermost bottom plate 2, which in turn reduces the weight of the battery case 10 and the energy consumption required to transport the battery case 10.

[0131] Here, as shown in Figure 11, the fifth cavity 21b is provided along the direction Y.

[0132] As optional, as shown in Figure 17, the outermost bottom plate 2 is further provided with a seventh opening 25c that communicates with the fifth cavity 21b. As shown in Figure 18, the battery case 10 may further include a second closing member 9. The second closing member 9 closes the seventh opening 25c, and accordingly, at least a portion of the second closing member 9 is located within the fifth cavity 21b. The outermost bottom plate 2 is further provided with a first through hole 26 that penetrates the second top wall 23a and the second bottom wall 23b. When the second closing member 9 does not close the seventh opening 25c, the first through hole 26 is able to communicate with the fifth cavity 21b. The second closing member 9 is further provided with a second through hole 91. When the second closing member 9 closes the seventh opening 25c and at least a portion of the second closing member 9 is located within the fifth cavity 21b, the second through-hole 91 communicates with the first through-hole 26, forming a hole that can perform a positioning or connecting role. The connection of the second closing member 9 to the bottom plate 2 improves the structural strength of the portion of the bottom plate 2 where the first through-hole 26 is provided.

[0133] As selectable, as shown in Figure 4, the outermost bottom plate 2 is integrally molded and connected to the side plate 1 or welded.

[0134] When the outermost bottom plate 2 and the side plate 1 are integrally molded and connected (for example, by integral molding using a casting process, extrusion process, or injection molding process), there are advantages to reducing the number of molds to be manufactured, increasing production efficiency, and improving the structural strength and dimensional accuracy between the outermost bottom plate 2 and the side plate 1.

[0135] As shown in Figure 19, a second embodiment of the present invention provides a method for manufacturing a battery case. As shown in Figure 2, the manufactured battery case 10 comprises two side plates 1 and at least two bottom plates 2, each bottom plate 2 distributed along the width direction (parallel to direction Z) of the battery case 10, and the outermost bottom plate 2 is connected to the corresponding side plate 1. The method for manufacturing a battery case according to the embodiment of the present invention includes step S1 and step S2. In step S1, the side plate 1 and the bottom plate 2 are manufactured by an integral molding process. In step S2, at least two bottom plates 2 are welded together by a friction welding process. The outermost bottom plate 2 and side plate 1, which are connected to each other as shown in Figure 4, are manufactured by an integral molding process. This integral molding process has the advantage of reducing the number of molds to be manufactured, increasing production efficiency, and improving the structural strength and dimensional accuracy between the outermost bottom plate 2 and side plate 1. The integral molding process may be a casting process, an extrusion process, or an injection molding process.

[0136] The first side walls 22a of at least two bottom plates 2 shown in Figure 10 are welded by a friction welding process. More specifically, the temperature of the first side walls 22a of the bottom plates 2 is increased by high-speed friction until at least a portion of the first side walls 22a is melted, then the molten portions of the first side walls 22a of the two bottom plates 2 are welded together, and after the first side walls 22a have cooled, a welded structure is formed between the first side walls 22a of the two bottom plates 2. Since auxiliary welding with other materials is not required in this welding process, the material of the welded structure between the first side walls 22a of the two bottom plates 2 is the same as the material of the bottom plate 2, that is, the structural strength of the welded structure between the first side walls 22a of the two bottom plates 2 is the same as the structural strength of the bottom plate 2, and the operational reliability of the formed structural plate located at the bottom of the battery case 10 is high.

[0137] Here, the first side walls 22a of the two base plates 2 can be rubbed against each other at high speed until at least a portion of the first side walls 22a of the two base plates 2 melt, or the first side walls 22a of the two base plates 2 can be rubbed simultaneously using the curved side wall of the high-speed rotating column, and the molten portions of the first side walls 22a of the two base plates 2 can be welded together. [Explanation of Symbols]

[0138] 10 Battery Case 1 Side panel 1a Outer wall 1b top 1c bottom 1d I-shaped rib section 11 Slide grooves 111 1st top wall 112 Inner wall 113 First bottom wall 12 hanging holes 13. First Cavity 14. First opening 15. Second Cavity 16. Second opening 17. Third Cavity 18. Third opening 181 First rounded chamfer structure 19. Fourth opening 191 Second rounded chamfer structure 2 Bottom plate 21a Fourth Cavity 211 Flow channel 21b Fifth Cavity 22a 1st side wall 221 First chamfered section 222 Second chamfered section 22b 2nd side wall 22c Support part 223 Third chamfered section 224 Fourth chamfered section 22d Separator 22e 3rd side wall 23a 2nd top wall 23b 2nd bottom wall 24a Liquid inlet 24b Liquid outlet 25a 5th opening 25b 6th opening 25c 7th opening 26 First through hole 3 Front panel 4 Rear plate 5 Top lid 6. Inlet fluid connecting tube 7. Outlet connection pipe 8. First closure member 81 Protrusion 82 spacing spaces 9. Second closure member 91 Second through hole 20 hooks 201 Bend part outer arc surface 202 Inner arc surface of bending part

Claims

1. It is a battery case, The battery case (10) comprises at least two welded bottom plates (2), each of which is provided with a fourth cavity (21a) for the flow of coolant, each bottom plate (2) includes a first side wall (22a) welded to an adjacent bottom plate (2), and the outermost bottom plate (2) includes a second side wall (22b) spaced apart from the first side wall (22a), and the battery case (10) further comprises side plates (1), each bottom plate (2) being distributed along the width or length of the battery case (10), and the outermost bottom plate (2) and the side plate (1) are integrally constructed. A battery case characterized in that a side plate (1) is provided with an inwardly recessed slide groove (11), the slide groove (11) is used for sliding engagement with a slide rail, a hanging hole (12) is provided in the side wall of the side plate (1) that surrounds the slide groove (11), and the hanging hole (12) is drilled by a hook (20) so that the side plate (1) is connected to the hook (20).

2. The battery case according to claim 1, characterized in that the outer wall (1a) of the side plate (1) provided along the height direction of the battery case (10) is provided with the slide groove (11), and the top wall (111) of the side plate (1) formed surrounding the slide groove (11) is provided with the hanging hole (12).

3. The battery case according to claim 2, wherein a first cavity (13) is further provided at the top (1b) of the side plate (1), the first cavity (13) communicates with the slide groove (11) via the hanging hole (12), and the first cavity (13) is used to accommodate at least a portion of the hook (20).

4. The battery case according to claim 3, wherein a second cavity (15) is further provided on the side of the side plate (1) away from the slide groove (11), a first opening (14) is provided on the side plate (1), the first opening (14) communicates with the hanging hole (12), the second cavity (15) communicates with the slide groove (11) via the first opening (14), and the second cavity (15) communicates with the first cavity (13) via the first opening (14).

5. The battery case according to claim 4, further comprising a third cavity (17) in the bottom (1c) of the side plate (1), a second opening (16) in the side plate (1), the second opening (16) communicating with the first opening (14), the second opening (16) communicating with the slide groove (11), the third cavity (17) communicating with the second cavity (15) via the second opening (16), and the third cavity (17) communicating with the slide groove (11) via the second opening (16).

6. The battery case according to claim 5, characterized in that a third opening (18) is provided in the outer wall (1a) of the side plate (1), the third opening (18) communicates with the second opening (16), and the third opening (18) is used to retract from the outer curved surface (201) of the bent portion of the hook (20).

7. The battery case according to claim 5, wherein the side plate (1) includes an I-shaped rib portion (1d), and the I-shaped rib portion (1d) partitions the first cavity (13), the second cavity (15), the third cavity (17), and the slide groove (11), and the hanging hole (12), the first opening (14), and the second opening (16) are provided in the I-shaped rib portion (1d).

8. The battery case according to claim 2, characterized in that a fourth opening (19) is provided in the outer wall (1a) of the side plate (1), the fourth opening (19) communicates with the hanging hole (12), and the fourth opening (19) is used to retract from the inner curved surface (202) of the bent portion of the hook (20).

9. The battery case according to claim 1, characterized in that the slide groove (11) has a predetermined width W1 satisfying 10 mm ≤ W1 ≤ 15 mm, and / or the slide groove (11) has a predetermined depth H1 satisfying 8 mm ≤ H1 ≤ 12 mm.

10. Each of the bottom plates (2) is provided so as to be distributed along the width or length of the battery case (10), and the fourth cavities (21a) of each bottom plate (2) are in communication with each other, and one outermost bottom plate (2) is provided with an inlet (24a), and the other outermost bottom plate (2) is provided with an outlet (24b). The battery case (10) further comprises an inlet connection tube (6) and an outlet connection tube (7), the inside of the inlet connection tube (6) is in communication with the inlet port (24a), and the inlet connection tube (6) is sealed and connected to the bottom plate (2) on which the inlet port (24a) is provided. The inside of the liquid outlet connecting pipe (7) is in communication with the liquid outlet (24b), and the liquid outlet connecting pipe (7) is sealed and connected to the bottom plate (2) on which the liquid outlet (24b) is provided. The battery case according to claim 1, characterized in that the inlet pipe (6) and the outlet pipe (7) are used to communicate with the corresponding external flow guide pipe.

11. The battery case according to claim 1, wherein the bottom plate (2) is provided with a fifth opening (25a) that communicates with the fourth cavity (21a), and the battery case (10) further comprises a first closing member (8) that closes the fifth opening (25a).

12. A method for manufacturing a battery case, The battery case (10) is the battery case according to any one of claims 1 to 11. The aforementioned manufacturing method is The steps include providing the slide groove (11) in the side plate (1) and providing the hanging hole (12) in the side wall of the side plate (1) that surrounds the slide groove (11), The steps include manufacturing the side plate (1) and the bottom plate (2), which are connected to each other, by an integral molding process, A method for manufacturing a battery case, comprising the step of welding at least two of the bottom plates (2) by a friction welding process.

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