Battery case and method for manufacturing battery case

Abstract

To provide a battery case and a method for manufacturing a battery case.SOLUTION: A battery case has at least two welded bottom plates, each bottom plate having a fourth cavity for the flow of a coolant and including a first side wall welded to an adjacent bottom plate. The first side wall has a predetermined width W2, and the outermost bottom plate includes a second side wall provided to be spaced apart from the first side wall, and the second side wall has a predetermined width W3, and satisfies 2W2≥W3. The battery case can solve a problem existing in battery cases in the prior art, that is, solve the problem that the battery case has a highly complex structure and is therefore difficult to manufacture.SELECTED DRAWING: Figure 10

Description

[Technical field]

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

[0002] (Related Applications) This application claims priority to a patent application having application number 202311395032.1 and filing date October 25, 2023, and priority to a utility model application having application number 202322873372.2 and filing date October 25, 2023, the entire contents of which are incorporated herein by cross-reference.

[0003] An energy storage battery is a power storage component necessary for a photovoltaic power generation system, and its main function is to store the power of the photovoltaic power generation system and supply power to a load when the amount of sunlight is insufficient, at night, and in an emergency. The energy storage battery is usually installed inside a battery case, but the battery case in the prior art has a problem that it is difficult to manufacture because of the complex structure of the battery case. Summary of the Invention [Problem to be solved by the invention]

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

[0005] In a first aspect, the present invention provides a battery case, the battery case comprising at least two welded bottom plates, each of which is provided with a fourth cavity for a coolant to flow through, each bottom plate including a first side wall welded to an adjacent bottom plate, the first side wall having a predetermined width W2, and an 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] The structural plate located at the bottom of the battery case is used to fix and support the battery located inside the battery case, and the structural plate having a large area is composed of at least two bottom plates having a small area. Each bottom plate is provided with a fourth cavity for the flow of the coolant. In detail, the coolant located outside the battery case flows into the fourth cavity. By the method of thermal conduction, the coolant can absorb heat generated during the operation of the battery installed in the bottom plate. The coolant that absorbed the heat can flow back to the outside of the bottom plate. By circulating the coolant back and forth in the fourth cavity, the battery is operated within a normal temperature range and the service life of the battery is improved. As can be seen from the above, the bottom plate is not only used as a part of the structural plate of the battery case to have the function of fixing and supporting the battery, but the fourth cavity provided in the bottom plate may also be used to circulate the coolant to realize heat dissipation. The structure of the bottom plate and the battery case according to the present invention is less complicated and the manufacturing difficulty of the bottom plate and the battery case is also lower than when a structural plate for fixing and supporting the battery is installed separately and a heat dissipation plate for heat dissipation is installed separately. Next, the bottom plate that the battery contacts has an integrated heat dissipation function, so that the formed heat conduction path is short, and the heat of the battery can be quickly conducted to the coolant in the bottom plate, and the heat dissipation efficiency is high. Since the area of ​​the structural plate at the bottom of the battery case is large, if a structural plate with a large area is directly manufactured at one time by the conventional manufacturing process, the structural strength and dimensional accuracy of the formed structural plate are relatively poor. On the other hand, the structural plate at the bottom of the battery case according to the present invention is formed by welding at least two bottom plates with a relatively small area. By this installation, at least two bottom plates with a relatively small area may be manufactured first in the production process. The structural strength and dimensional accuracy of each bottom plate manufactured by the existing manufacturing process are relatively high. Next, the formed bottom plate may be welded to form a bottom plate structural plate required for the battery case. The structural strength and dimensional accuracy of the formed structural plate are also relatively high. In this way, the actual usage needs can be better met. 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 connection structure of the two bottom plates. The welding method has the advantages of high strength of the connection structure and high connection reliability.The outermost bottom plate further includes a second side wall, the second side wall is structured to meet the shape, size or structural strength of the bottom plate itself, and the second side wall is not 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 satisfies 2W2≧W3. With this setting, the sum of the widths W2 of the two adjacent first side walls is large, so that in the welding process, the width of the meltable connection area between the two adjacent bottom plates is large, 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, and the welded structure between the two adjacent bottom plates is unlikely to have structural problems such as cracks, breaks or bends, so that the operational reliability of the structural plate formed by welding at least two bottom plates is high.

[0007] Preferably, the relationship 7 mm≦W2≦10 mm or 3 mm≦W3≦8 mm is satisfied.

[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 the first side wall and the second side wall, the second top wall, the first side wall and the second bottom wall being at least part of a structure for surrounding and forming a fourth cavity, and a connection point of any one of the first side walls between a side facing away from an adjacent first side wall and the corresponding second top wall includes a first chamfered portion, and / or a connection point of any one of the first side walls between a side facing away from an adjacent first side wall and the corresponding second bottom wall includes a second chamfered portion.

[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, which satisfies 5 mm≦H2≦8 mm.

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

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

[0013] Preferably, the connection point between the support and the second top wall includes a third chamfered portion, and / or the connection point between the support 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 to form at least two parallel and communicating flow paths.

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

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

[0018] Preferably, the bottom plates are arranged so as to be distributed along the width direction or length direction of the battery case, the fourth cavities of each bottom plate are connected to each other, and one outermost bottom plate is provided with a liquid inlet port and the other outermost bottom plate is provided with a liquid outlet port.

[0019] Preferably, the battery case further comprises an inlet connection pipe and an outlet connection pipe, the interior of the inlet connection pipe communicating with the inlet port and the inlet connection pipe being sealed connected to a bottom plate provided with the inlet port, the interior of the outlet connection pipe communicating with the outlet port and the outlet connection pipe being sealed connected to the bottom plate provided with the outlet port, and the inlet connection pipe and the outlet connection pipe being used to communicate with corresponding external flow tubes.

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

[0021] Preferably, the battery case further includes side plates, each bottom plate being distributed along the width direction or length direction 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 which is used for sliding engagement with the slide rail, the side plate being provided with a side wall surrounding and forming the slide groove, and the hanger 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 a slide groove recessed inward, and the fixing device for accommodating the battery case may include a slide rail, and the slide groove may slide-fit with the slide rail. This assembly method makes it easy for the battery case to be quickly attached to the fixing device in a sliding manner, and the assembly efficiency is high. Of course, this assembly method makes it easy for the battery case to be quickly detached from the fixing device in a sliding manner, and the removal efficiency is high. The side plate of the battery case is further provided with a hanging hole. The hanging hole is drilled by a hook of a lifting device (e.g., a crane, an overhead traveling vehicle, a crane, or other device) to connect 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 slide groove and the slide rail are aligned to slide-fit the slide groove and the slide rail. Or, the hook may move the battery case from the fixing device to another position. Since the hanging hole is provided on the side wall to surround and form the sliding groove in the side plate, the degree of structural compactness between the sliding groove and the hanging hole is high due to this installation. Under the condition that the size of the structure for installing the sliding groove and the hanging hole in the side plate is small and the size in 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, and the loading rate is high. Correspondingly, the weight of the side plate is light, and the energy consumption for transporting the battery case is also low.

[0023] Preferably, a slide groove is provided in an outer wall of the side plate that is provided along the height direction of the battery case, and a hanging hole is provided in a top wall of the side plate that surrounds and forms the slide groove.

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

[0025] Preferably, a second cavity is further provided on the side of the side plate facing away from the slide groove, and a first opening is provided in the side plate, the first opening communicating with the hanging hole, the second cavity communicating with the slide groove via the first opening, and the second cavity communicating with the first cavity via the first opening.

[0026] Preferably, a third cavity is further provided at the bottom of the side plate, a second opening is provided in the side plate, the second opening is connected to the first opening, the second opening is also connected to the slide groove, the third cavity is connected to the second cavity via the second opening, and the third cavity is connected to the slide groove via 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 retracting from the outer arc surface of the bent portion of the hook.

[0028] Preferably, the side plate includes a U-shaped rib portion, which divides the side plate into a first cavity, a second cavity, a third cavity, and a slide groove, and the hanging hole, the first opening, and the second opening are provided in the U-shaped rib portion.

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

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

[0031] A second aspect of the present invention provides a method for manufacturing a battery case, the method comprising the steps of: Step S1: manufacturing a side plate and a bottom plate to be connected to each other by an integral molding process; and step S2 of welding the at least two bottom plates together by a friction welding process. Effect of the Invention

[0032] The outermost bottom plate and side plate connected to each other are manufactured by an integral molding process, which has the advantages 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 plate. The integral molding process may be a casting process, an extrusion molding process, or an injection molding process. The first side walls of at least two bottom plates are welded by a friction welding process. In detail, the temperature of the first side wall of the bottom plate is increased by high-speed friction until at least a part of the first side wall is melted, and then the melted parts of the first side walls of the two bottom plates are welded, and after the first side walls are cooled, a welded structure is formed between the first side walls of the two bottom plates. Since this welding process does not require auxiliary welding by other materials, 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, that is, the structural strength of the welded structure between the first side walls of the two bottom plates and the structural strength of the bottom plate are the same, and the operating reliability of the formed structural plate located at the bottom of the battery case is high. Here, the first side walls of the two bottom plates can be rubbed against each other at high speed until at least a portion of the first side walls of the two bottom plates melts, or the curved side wall of the high-speed rotating cylinder can be used to rub the first side walls of the two bottom plates simultaneously, and the melted portions of the first side walls of the two bottom plates can be welded.

[0033] In order to more clearly describe the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings referred to in the following description are only some embodiments of the present invention, and those skilled in the art can obtain other drawings based on these drawings without labors worthy of inventive step. [Brief description of the drawings]

[0034] [Figure 1] FIG. 2 is a schematic diagram of the three-dimensional structure of a battery case according to one specific embodiment of the present invention. [Diagram 2] FIG. 2 is a structural exploded schematic diagram of the battery case in FIG. [Diagram 3] FIG. 3 is a local enlarged schematic view of part A in FIG. 2. [Figure 4] FIG. 2 is a schematic diagram of the structure of the bottom plate and side plate. [Diagram 5] 5 is a local enlarged schematic view of part B in FIG. 4. FIG. [Figure 6] FIG. 2 is a structural schematic diagram of a specific embodiment of a hook. [Figure 7] 3 is a cross-sectional view of the bottom plate and the side plate in the CC direction in FIG. 2. [Figure 8] FIG. 8 is a local enlarged schematic view of a portion D in FIG. [Figure 9] FIG. 9 is a structural schematic diagram of the U-shaped rib portion in FIG. 8. [Figure 10] FIG. 8 is a schematic diagram showing the structure of part E in FIG. [Figure 11] 3 is a cross-sectional view of the bottom plate, the first closing member, and the second closing member in the direction FF in FIG. 2. [Figure 12] FIG. 2 is a schematic diagram of the exploded structure of the two bottom plates. [Figure 13] This is a schematic diagram of the structure of the three bottom plates. [Figure 14] 13 is a local enlarged schematic view of a portion G in FIG. 12. FIG. [Figure 15] FIG. 4 is a structural schematic diagram of a first closing member according to one specific embodiment. [Figure 16] 13 is a structural schematic diagram of another specific embodiment of the first blocking member. FIG. [Figure 17] 13 is a schematic enlarged view of a portion H in FIG. 12. FIG. [Figure 18] FIG. 4 is a structural schematic diagram of a second blocking member according to one specific embodiment. [Figure 19] 2 is a flow chart of a battery case manufacturing method according to a specific embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

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

[0036] Obviously, the described embodiments are only some of the embodiments of the present invention, but not all of the embodiments. Based on the embodiments of the present invention, all other embodiments that a person skilled in the art can obtain without inventive efforts fall within the scope of protection of the present invention.

[0037] The terms used in the embodiments of the present invention are only for the purpose of describing particular embodiments, and are not intended to limit the present invention. The singular forms "a," "the," and "the" used in the embodiments of the present invention and the appended claims are also intended to include the plural forms unless the context clearly dictates otherwise.

[0038] It should be understood that the term "and / or" used in this specification is only a relational relationship to describe related objects, and indicates that three kinds of relations may exist. For example, A and / or B can indicate three kinds of situations: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the symbol " / " in this specification generally indicates that the related objects before and after are in an "or" relationship.

[0039] As shown in FIG. 1, a first aspect of the embodiment of the present invention provides a battery case 10. The inside of the battery case accommodates a battery (not shown), and the battery case protects the battery. In practical application, the battery case may be accommodated in a fixed device such as a holder, a box, or a cabinet. As shown in FIG. 2, the battery case 10 includes a side plate 1, a bottom plate 2, a front plate 3, a rear plate 4, and a top cover 5. Two side plates 1 are connected to the bottom plate 2, the two side plates 1 are arranged to face each other, the front plate 3 is connected to the bottom plate 2, the rear plate 4 is connected to the bottom plate 2, the front plate 3 and the rear plate 4 are arranged to face each other, at least two of the side plates 1, the front plate 3, and the rear plate 4 are connected to the top cover 5, and the side plates 1, the bottom plate 2, the front plate 3, the rear plate 4, and the top cover 5 surround and form a space for accommodating a battery. The contents described later in this specification will first introduce the structure of the side plate 1, and then introduce the structure of the bottom plate 2. The directions X, Y and Z described in this specification are perpendicular to each other, and the dashed lines in the drawings of this application are structure boundaries.

[0040] As shown in Fig. 3, the side plate 1 is provided with a slide groove 11 recessed inward, and the slide groove 11 is slidably fitted with a slide rail (not shown). As shown in Figs. 4 and 5, a hanging hole 12 is provided in a side wall of the side plate 1 that surrounds and forms the slide groove 11, and the hanging hole 12 is drilled by a hook 20 shown in Fig. 6 to connect the side plate 1 to the hook 20.

[0041] As shown in FIG. 3, the side plate 1 of the battery case 10 may be provided with a slide groove 11 recessed inward, and the fixing device (not shown) for accommodating 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 in a sliding manner, and the assembly efficiency is high. Of course, this assembly method also makes it easy to quickly detach the battery case 10 from the fixing device in a sliding manner, and the removal efficiency is high. As shown in FIG. 4 to FIG. 5, the side plate 1 of the battery case 10 is further provided with a lifting hole 12. The lifting hole 12 is drilled by a hook 20 (shown in FIG. 6) of a lifting device (for example, a device such as a crane, an overhead traveling vehicle, or a crane) to connect 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. Or, the hook 20 may move the battery case 10 from the fixing device to another position. Since the hanging hole 12 is provided on the side wall for surrounding and forming the slide groove 11 in the side plate 1, the degree of structural compactness between the slide groove 11 and the hanging hole 12 is high by this installation. Under the condition that the size (e.g., the size along the direction X) of the structure for installing the slide groove 11 and the hanging hole 12 in the side plate 1 is small and the size along other directions (e.g., the direction Z and the direction 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, and the loading rate is high. Correspondingly, the weight of the side plate 1 is light, and the energy consumption for transporting the battery case 10 is also low.

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

[0043] As shown in Figs. 7 and 8, the cross section of the slide groove 11 perpendicular to the direction Y may have a rectangular or polygonal shape such as an isosceles trapezoid.

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

[0045] Alternatively, as shown in FIG. 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 the X direction) of the battery case 10, and 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 the X direction) of the fixing device, and this installation simplifies the structure of the fixing device for sliding and fitting with the battery case 10. Since the outer wall 1a belongs to the structure of the battery case 10 at a general viewing angle, the slide groove 11 is easily observed by the user, which makes it easy for the user to quickly and accurately slide and fit the slide groove 11 and the slide rail. For the same reason, the hanging hole 12 is also easily observed by the user, which makes it easy for the user to quickly and accurately drill the hanging hole 12 with 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 to surround and form the slide groove 11, and because the gravity of the battery case 10 makes it difficult for the hook 20 to come off the hanging hole 12, the connection reliability between the battery case 10 and the hook 20 is high.

[0046] In another embodiment (not shown), the bottom wall of the side panel 1 may be provided with the slide groove 11 and the hanging hole 12. The contents described later in this specification will be mainly described taking as an example that the slide groove 11 and the hanging hole 12 are provided on the outer wall 1a of the side panel 1.

[0047] Optionally, as shown in FIG. 8, a first cavity 13 is further provided on the top 1b of the side panel 1, the first cavity 13 being connected to the slide groove 11 via the hanging hole 12, and the first cavity 13 accommodating at least a portion of the hook 20.

[0048] A part of the structure of the hook 20 shown in FIG. 6 may be moved into the first cavity 13 via the slide groove 11 and the hanging hole 12 shown in FIG. 8 to connect the hook 20 to the side plate 1. This arrangement makes the space of the structure of the part that accommodates the hook 20 in the side plate 1 large, the number of points for connecting to the hook 20 in the internal structure of the side plate 1 is large, the area of ​​the internal structure of the side plate 1 that connects to the hook 20 is large, and the points of the internal structure of the side plate 1 that connect to the hook 20 are located in positions close to the inside of the side plate 1. Accordingly, the length or volume of the structure located in the side plate 1 in the hook 20 may be increased, the structural strength of the hook 20 is large, and the connection reliability between the side plate 1 and the hook 20 is high. The arrangement of the first cavity 13 makes the weight 1 of the battery case 10 light, and the energy consumption of transporting the battery case 10 is also low.

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

[0050] As shown in FIG. 8, the cross section of the first cavity 13 perpendicular to the direction Y may have a polygonal shape such as a rectangle.

[0051] Optionally, as shown in FIG. 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 connected to the hanging hole 12, the second cavity 15 is connected to the slide groove 11 via the first opening 14, and the second cavity 15 is connected to the first cavity 13 via the first opening 14.

[0052] A part of the structure of the hook 20 shown in Fig. 6 may be located in the first opening 14 and the second cavity 15 shown in Fig. 8. This arrangement provides a larger space for accommodating a part of the structure of the hook 20 in the side panel 1, provides more points for connecting with the hook 20 in the internal structure of the side panel 1, and provides a larger area for connecting with the hook 20 in the internal structure of the side panel 1. Accordingly, the length or volume of the structure in the hook 20 located in the side panel 1 becomes larger, and the structural strength of the hook 20 becomes greater, thereby improving the connection reliability between the side panel 1 and the hook 20. The arrangement of the second cavity 15 makes the weight 1 of the battery case 10 lighter, and the energy consumption for transporting the battery case 10 also becomes smaller.

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

[0054] As shown in FIG. 8, the cross section of the second cavity 15 perpendicular to the direction Y may have a polygonal shape such as a rectangle.

[0055] Optionally, as shown in FIG. 8, a third cavity 17 is further provided in the bottom 1c of the side panel 1, and a second opening 16 is provided in the side panel 1, the second opening 16 is connected to the first opening 14, the second opening 16 is connected to the slide groove 11, the third cavity 17 is connected to the second cavity 15 via the second opening 16, and the third cavity 17 is connected to the slide groove 11 via the second opening 16.

[0056] A part of the structure of the hook 20 shown in Fig. 6 may be located in the second opening 16 and the third cavity 17 shown in Fig. 8. This arrangement provides a larger space for accommodating a part of the structure of the hook 20 in the side panel 1, provides more points for connecting with the hook 20 in the internal structure of the side panel 1, and provides a larger area for connecting with the hook 20 in the internal structure of the side panel 1. Accordingly, the length or volume of the structure in the hook 20 located in the side panel 1 becomes larger, and the structural strength of the hook 20 becomes greater, thereby improving the connection reliability between the side panel 1 and the hook 20. The arrangement of the third cavity 17 reduces the weight 1 of the battery case 10 and reduces the energy consumption for transporting the battery case 10.

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

[0058] As shown in FIG. 8, the cross section of the third cavity 17 perpendicular to the direction Y may have a polygonal shape such as a rectangle.

[0059] Optionally, as shown in FIG. 8, a third opening 18 is provided in the outer wall 1a of the side panel 1, the third opening 18 being connected to the second opening 16, and the third opening 18 is used to retreat from the outer arc surface 201 of the bent portion of the hook 20 shown in FIG. 6.

[0060] At least a part of the outer arc surface 201 of the bent part of the hook 20 shown in Fig. 6 can be moved into the slide groove 11 or other internal space of the side panel 1 via the third opening 18 shown in Fig. 8, thereby facilitating connection of a part of the structure of the hook 20 to the internal structure of the side panel 1. The provision of the third opening 18 can reduce the possibility of problems occurring in the locking between the hook 20 and the structure of the side panel 1 during connection, making it easier for the user to quickly connect the hook 20 to the side panel 1.

[0061] 5, the surface of the outer wall 1a of the side panel 1 for surrounding and forming the third opening 18 includes a first round chamfered structure 181, and the provision of the first round chamfered structure 181 can reduce the stress concentration of the structure for forming the third opening 18 in the side wall 1. Therefore, the possibility of a crack problem occurring in the structure for forming the third opening 18 in the side panel 1 is low.

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

[0063] Optionally, as shown in Fig. 8, the side plate 1 includes a U-shaped rib portion 1d, which divides the side plate 1 into a first cavity 13, a second cavity 15, a third cavity 17, and a slide groove 11. This arrangement makes the side plate 1 light in weight and high in structural strength, and reduces the possibility of structural problems such as bending deformation occurring in the side plate 1. The hanging hole 12, the first opening 14, and the second opening 16 are provided in the U-shaped rib portion 1d, thereby forming an arrangement in which 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 communicate with each other. In this way, a part of the structure of the hook 20 can be positioned in 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 the technical effect of improving the connection reliability between the side panel 1 and the hook 20 in the above content. A description will not be repeated here.

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

[0065] 9, the U-shaped rib portion 1d includes a first top wall 111, an inner wall 112, and a first bottom wall 113 for surrounding and forming 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] Optionally, as shown in FIG. 8, a fourth opening 19 is provided in the outer wall 1a of the side panel 1, the fourth opening 19 communicates with the hanging hole 12, and the fourth opening 19 is used to retreat from the inner arc surface 202 of the bent portion of the hook 20 shown in FIG. 6.

[0067] At least a part of the inner arc surface 202 of the bent part of the hook 20 shown in Fig. 6 can be moved to the slide groove 11 or other internal space of the side panel 1 via the fourth opening 19 shown in Fig. 8, thereby facilitating connection of a part of the structure of the hook 20 to the internal structure of the side panel 1. The provision of the fourth opening 19 can reduce the possibility of problems occurring in the hook 20 and the structure of the side panel 1 from locking during connection, making it easier for the user to quickly connect the hook 20 to the side panel 1.

[0068] 5, the surface of the outer wall 1a of the side panel 1 for surrounding and forming the fourth opening 19 includes a second round chamfered structure 191, and the provision of the second round chamfered structure 191 can reduce the stress concentration of the structure for forming the fourth opening 19 in the side wall 1. Therefore, the possibility of a crack problem occurring in the structure for forming the fourth opening 19 in the side panel 1 is low.

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

[0070] Optionally, as shown in Fig. 8, the slide groove 11 has a predetermined width W1 (size along the direction X), which satisfies 10mm <= W1 <= 15mm. W1 may be specifically 10mm, 11mm, 12mm, 13mm, 14mm, or 15mm.

[0071] As shown in Fig. 8, when W1 is smaller than 10mm, the width W1 of the slide groove 11 is small, and the width of the slide rail of the fixing device (not shown) is accordingly small, the structural strength of the slide rail is low, and the connection reliability between the battery case 10 and the fixing device is low. When the width W1 of the slide groove 11 is larger than 15mm, the width W1 of the slide groove 11 is large, the height (size along the direction X) of the side plate 1 is large, and the volume of the side plate 1 is large, so that the space of the fixing device occupied by a single battery case 10 is large, and the number of battery cases 10 accommodated in the fixing device is small, that is, the loading rate is low, the weight of the side plate 1 is heavy, and the energy consumption of transporting the battery case 10 is large. Therefore, it is preferable that the width W1 of the slide groove 11 is 10mm to 15mm.

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

[0073] 8, when H1 is smaller than 8 mm, the depth H1 of the slide groove 11 is small, and the space in the slide groove 11 for accommodating the slide rail of the fixing device (not shown) is small, so that the slide rail is likely to come off the slide groove 11 and the sliding engagement between the slide groove 11 and the slide rail is likely to be lost, that is, the connection between the battery case 10 and the fixing device is likely to be lost. When H2 is larger 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 preferable that the depth H1 of the slide groove 11 is 8 mm to 12 mm.

[0074] The following description of this specification will introduce the structure of the bottom plate 2.

[0075] As shown in FIG. 2, the structural plate located at the bottom of the battery case 10 is used to fix and support the battery (not shown) located inside the battery case 10, and the structural plate having a large area is composed of at least two bottom plates 2 having a small area. As shown in FIG. 10 to FIG. 11, a fourth cavity 21a is provided in each bottom plate 2, and the fourth cavity 21a is used for the circulation of the cooling liquid (not shown). In detail, the cooling liquid located outside the battery case 10 flows into the fourth cavity 21a. By the method of heat conduction, the cooling liquid can absorb heat generated during the operation of the battery (not shown) installed in the bottom plate 2. The cooling liquid that has absorbed the heat can flow back to the outside of the bottom plate 2. By circulating the cooling liquid back and forth within the fourth cavity 21a, the battery is operated within a normal temperature range, and the service life of the battery is improved. As can be seen from the above, the bottom plate 2 is not only used as a part of the structural plate of the battery case 10 to have the function of fixing and supporting the battery, but the fourth cavity 21a provided in the bottom plate 2 may be used to circulate the coolant, so that the bottom plate 2 can realize heat dissipation. Compared to installing a structural plate for fixing and supporting the battery alone and a heat dissipation plate for heat dissipation alone, the complexity of the structure of the bottom plate 2 and the battery case 10 according to the embodiment of the present invention is lower, and the difficulty of manufacturing the bottom plate 2 and the battery case 10 is also lower. Next, since the bottom plate 2 that the battery contacts has an integrated heat dissipation function, the formed heat conduction path is short, and the heat of the battery can be quickly conducted to the coolant in the bottom plate 2, and the heat dissipation efficiency is high. Since the area of ​​the structural plate at the bottom of the battery case 10 is large, if a structural plate with a large area is directly manufactured at one time by the conventional manufacturing process, the structural strength and dimensional accuracy of the formed structural plate are relatively poor. On the other hand, the structural plate at the bottom of the battery case 10 according to the embodiment of the present invention is formed by welding at least two bottom plates 2 each having a relatively small area. Due to this arrangement, in the production process, at least two bottom plates 2 each having a relatively small area may be first fabricated. The structural strength and dimensional accuracy of each bottom plate 2 fabricated by the existing manufacturing process are relatively high. Then, the formed bottom plates 2 may be welded to form a bottom 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 can better meet the actual needs of use. 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, that is, the two welded first side walls 22a form a connection structure of the two bottom plates 2. The welding method has the advantage of high strength of the connection structure and high connection reliability. As shown in FIG. 8, the outermost bottom plate 2 further includes a second side wall 22b, and the second side wall 22b is a structure for satisfying 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 the direction Z), and the second side wall 22b has a predetermined width W3 (size along the 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 that during the welding process, the width of the meltable 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, and the welded structure between the two adjacent bottom plates 2 is unlikely to have structural problems such as cracks, breaks or bending, so that the operational reliability of the structural plate formed by welding at least two bottom plates 2 is high.

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

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

[0078] Alternatively, as shown in Fig. 8, the width W3 satisfies 3mm <= W3 <= 8mm. The width W3 may be specifically 3mm, 4mm, 5mm, 6mm, 7mm or 8mm.

[0079] As shown in Fig. 8, when the width W3 of the second side wall 22b is smaller than 3mm, the width of the second side wall 22b is too small, the structural strength of the second side wall 22b is low, and structural problems such as cracks, breakage, or bending deformation are likely to occur. When the width W3 of the second side wall 22b is larger than 10mm, the width of the second side wall 22b is too large, and under the condition that the size of the single bottom plate 2 along the direction Z is limited and the distance between the second side wall 22b and the first side wall 22a is limited, the size of the fourth cavity 21a along the direction Z is small, the amount of cooling liquid that can be contained in the fourth cavity 21a is small, and the heat dissipation efficiency is poor. Therefore, it is preferable that the width W2 of the first side wall 22a is 3mm to 8mm.

[0080] Alternatively, as shown in Fig. 10, the width W2 satisfies 7mm <= W2 <= 10mm. Specifically, the width W2 may be 7mm, 8mm, 9mm or 10mm.

[0081] As shown in Fig. 10, when the width W2 of the first side wall 22a is smaller than 7mm, the width of the first side wall 22a is too small, so that the width of a part of the welded structure for forming the bottom plate 2 is small, the structural strength of the welded structure formed is low, and the welded structure formed is likely to have structural problems such as cracks, breakage, and bending deformation. When the width W2 of the first side wall 22a is larger than 10mm, the width of the first side wall 22a is too large, so that under the condition that 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, the amount of cooling liquid that can be contained in the fourth cavity 21a is small, and the heat dissipation efficiency is poor. Therefore, it is preferable that the width W2 of the first side wall 22a is 7mm to 10mm.

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

[0083] The structural plate at the bottom of the battery case 10 is composed of two bottom plates 2, each of which further includes a second side wall 22b spaced apart from the 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 are structured to surround and form the fourth cavity 21a.

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

[0086] In addition, the material of the second top wall 23a may be metal, so that the heat transfer efficiency is higher, and the second top wall 23a can quickly transfer the heat to the cooling liquid 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 separated from the second bottom wall 23b. The material of the heat absorbing layer may be a carbon-nitrogen co-permeation layer, a nitrogen-oxygen co-permeation layer, a carbon-oxygen co-permeation layer, or a carbon-nitrogen-oxygen co-permeation layer. Any of the above materials may have at least a part of the heat absorbing layer in black or a dark color close to black. Compared with other colors (stainless steel or aluminum silver-white), a heat absorbing layer with a black or dark color close to black appearance has a high efficiency of absorbing heat radiation electromagnetic waves, and the frequency range of heat radiation electromagnetic waves that can be absorbed by a heat absorbing layer with a black or dark color close to black appearance is large. Therefore, the heat absorbing layer can quickly and in large quantities absorb heat radiation electromagnetic waves generated during the operation of the battery. That is, the heat absorbing layer quickly absorbs the heat of the battery by utilizing the heat radiation principle, 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] Optionally, as shown in FIG. 10, the connection point of any one of the first side walls 22a between the side facing away from the adjacent first side wall 22a and the corresponding second top wall 23a includes a first chamfered portion 221, and the provision of the first chamfered portion 221 can reduce the degree of stress concentration at the connection point between the first side wall 22a and the second top wall 23a, thereby reducing the possibility of structural problems such as cracks, breaks or deformation occurring at the connection point between the first side wall 22a and the second top wall 23a.

[0089] Optionally, as shown in FIG. 10, the connection point between the side of any one of the first side walls 22a facing away from the adjacent first side wall 22a and the corresponding second bottom wall 23b includes a second chamfered portion 222. By providing the second chamfered portion 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, and the possibility of structural problems such as cracks, breaks or deformation occurring at the connection point between the first side wall 22a and the second bottom wall 23b can be reduced.

[0090] Optionally, as shown in Fig. 10, the first chamfered portion 221 is a rounded chamfered structure, and the first chamfered portion 221 has a predetermined radius R1, which satisfies 1mm≦R1≦3mm. The radius R1 may be specifically 1mm, 1.5mm, 2mm, 2.5mm, or 3mm.

[0091] As shown in FIG. 10, when the radius R1 is smaller than 1 mm, the radius R1 of the first chamfered portion 221 is small. The stress concentration at the connection between the first side wall 22a and the second top wall 23a is high, and structural problems such as cracks, breaks, or deformations are likely to occur at the connection between the first side wall 22a and the second top wall 23a. On the other hand, it is difficult to manufacture the first chamfered portion 221 having a small radius R1 under the condition that the dimensional accuracy is guaranteed. When the radius R1 is larger than 3 mm, the radius R1 of the first chamfered portion 221 is large, the volume of the connection between the first side wall 22a and the second top wall 23a is large, and under the condition that the volume of the single bottom plate 2 is constant, the volume of the fourth cavity 21a is small, the amount of cooling liquid that can be contained in the fourth cavity 21a is small, and the heat dissipation efficiency is poor. Therefore, it is preferable that the radius R1 is 1 mm to 3 mm.

[0092] In another embodiment (not shown), the first chamfer 221 may be a corner chamfer structure.

[0093] Optionally, as shown in Fig. 10, the second chamfered portion 222 is a rounded chamfered structure, and the second chamfered portion 222 has a predetermined radius R2, which satisfies 1mm≦R2≦3mm. The radius R2 may be specifically 1mm, 1.5mm, 2mm, 2.5mm, or 3mm.

[0094] As shown in FIG. 10, when the radius R2 is smaller than 1 mm, the radius R2 of the second chamfered portion 222 is small. The stress concentration at the connection between the first side wall 22a and the second bottom wall 23b is high, and structural problems such as cracks, breaks, or deformations are likely to occur at the connection between the first side wall 22a and the second bottom wall 23b. On the other hand, the manufacturing difficulty of the second chamfered portion 222 having a small radius R2 is high under the condition that the dimensional accuracy is guaranteed. When the radius R2 is larger than 3 mm, the radius R2 of the second chamfered portion 222 is large, the volume of the connection between the first side wall 22a and the second bottom wall 23b is large, and under the condition that the volume of the single bottom plate 2 is constant, the volume of the fourth cavity 21a is small, the amount of cooling liquid that can be contained in the fourth cavity 21a is small, and the heat dissipation efficiency is poor. Therefore, it is preferable that the radius R2 is 1 mm to 3 mm.

[0095] In another embodiment (not shown), the second chamfer 222 may be a corner chamfer structure.

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

[0097] 10, when the height H2 is smaller 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 accommodated in the fourth cavity 21a is small, and the heat dissipation efficiency is poor. When the height H2 is larger 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 of transporting the battery case 10 is large. Therefore, it is preferable that the height H2 is 5 mm to 8 mm.

[0098] Optionally, as shown in Fig. 10, the bottom plate 2 further includes a support 22c located in the fourth cavity 21a, and the second bottom wall 23b is connected to the second top wall 23a via the support 22c. With this arrangement, the support 22c serves to improve the structural strength of the bottom plate 2, and the second top wall 23a and the second bottom wall 23b are unlikely to suffer structural problems such as bending, cracking, or breaking.

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

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

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

[0102] Optionally, as shown in Fig. 10, the support portion 22c has a predetermined width W4 (size parallel to the direction Z) that satisfies 3mm <= W4 <= 5mm. The width W4 may be specifically 3mm, 3.5mm, 4mm, 4.5mm, or 5mm.

[0103] 10, when the width W4 of the support portion 22c is smaller than 3 mm, the structural strength of the support portion 22c is low, the effect of the support portion 22c in improving the structural strength of the bottom plate 2 is weak, and structural problems such as bending deformation, cracks, or breakage are likely to occur in the second top wall 23a and the second bottom wall 23b. When the width W4 of the support portion 22c is larger than 5 mm, the space of the fourth cavity 21a occupied by the support portion 22c is large, the amount of cooling liquid that can be contained in the fourth cavity 21a is small, and the heat dissipation efficiency is poor. Therefore, it is preferable that the width W4 of the support portion 22c is 3 mm to 5 mm.

[0104] Optionally, as shown in Fig. 10, the connection portion between support portion 22c and second top wall 23a includes a third chamfered portion 223. The provision of third chamfered portion 223 can reduce the stress concentration at the connection portion between support portion 22c and second top wall 23a, thereby reducing the possibility of structural problems such as cracks, breakage, or deformation occurring at the connection portion between support portion 22c and second top wall 23a.

[0105] Optionally, as shown in Fig. 10, the connection portion between the support portion 22c and the second bottom wall 23b includes a fourth chamfered portion 224. The provision of the fourth chamfered portion 224 can reduce the degree of stress concentration at the connection portion between the support portion 22c and the second bottom wall 23b, and reduces the possibility of structural problems such as cracks, breakage, or deformation occurring at the connection portion between the support portion 22c and the second bottom wall 23b.

[0106] Optionally, as shown in Fig. 10, the third chamfered portion 223 is a rounded chamfered structure, and the third chamfered portion 223 has a predetermined radius R3, which satisfies 1mm≦R3≦3mm. The radius R3 may be specifically 1mm, 1.5mm, 2mm, 2.5mm, or 3mm.

[0107] As shown in Fig. 10, when the radius R3 is smaller than 1 mm, the radius R3 of the third chamfered portion 223 is small, the stress concentration at the connection between the support portion 22c and the second top wall 23a is high, and structural problems such as cracks, breakage, or deformation are likely to occur at the connection between the support portion 22c and the second top wall 23a. On the other hand, under the condition that the dimensional accuracy is guaranteed, the manufacturing difficulty of the third chamfered portion 223 having a small radius R3 is high. When the radius R3 is larger than 3 mm, the radius R3 of the third chamfered portion 223 is large, the volume of the connection between the support portion 22c and the second top wall 23a is large, and under the condition that the volume of the 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 preferable that the radius R3 is 1 mm to 3 mm.

[0108] In another embodiment (not shown), the third chamfer 223 is a corner chamfer structure.

[0109] Optionally, as shown in Fig. 10, the fourth chamfered portion 224 is a rounded chamfered structure, and the fourth chamfered portion 224 has a predetermined radius R4, which satisfies 1mm≦R4≦3mm. The radius R4 may be specifically 1mm, 1.5mm, 2mm, 2.5mm, or 3mm.

[0110] As shown in Fig. 10, when the radius R4 is smaller than 1 mm, the radius R4 of the fourth chamfered portion 224 is small, the stress concentration at the connection between the support portion 22c and the second bottom wall 23b is high, and structural problems such as cracks, breakage, or deformation are likely to occur at the connection between the support portion 22c and the second bottom wall 23b. On the other hand, under the condition that the dimensional accuracy is guaranteed, the manufacturing difficulty of the fourth chamfered portion 224 having a small radius R4 is high. When the radius R4 is larger than 3 mm, the radius R4 of the fourth chamfered portion 224 is large, the volume of the connection between the support portion 22c and the second bottom wall 23b is large, and under the condition that the volume of the 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 preferable that the radius R4 is 1 mm to 3 mm.

[0111] In another embodiment (not shown), the fourth chamfer 224 is a corner chamfer structure.

[0112] Alternatively, as shown in FIG. 11, the support 22c has a plate-like structure, and the fourth cavity 21a is partitioned by the support 22c to form at least two parallel and communicating flow paths 211. With this arrangement, the flow paths 211 are used to guide the cooling liquid to flow regularly along the extension direction of the flow paths 211 (direction parallel to the direction Y), improving the flow efficiency of the cooling liquid. Next, the flow paths 211 are further used to divide the cooling liquid to form at least two flow paths of fluid, each of which absorbs heat from the corresponding part in the bottom plate 2, and the difference in efficiency of each part in the bottom plate 2 transferring heat to the cooling liquid is small. Therefore, the arrangement of the flow paths 211 can improve the heat dissipation efficiency.

[0113] The greater the number of support portions 22c, the greater the number of flow paths 211 that are formed.

[0114] Optionally, the cross-sectional shape of the flow passage 211 is rectangular (as shown in FIG. 10), circular, semicircular, elliptical or hexagonal, and any of the above cross-sectional shapes of the flow passage 211 can meet the demand for the flow of the cooling liquid.

[0115] Optionally, as shown in FIG. 11, the bottom plate 2 further includes at least two separators 22d positioned within the same flow path 211, the separators 22d being parallel to the plate-shaped support portion 22c, and each separator 22d positioned 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 FIG. 11, in the process in which the cooling liquid flows through the flow path 211, flat flow layers that are stacked in multiple layers and arranged along the flow direction of the flow path 211 are easily formed. The flat flow layers closer to the support portion 22c in the cooling liquid are easily able to absorb heat from the support portion 22c, or the flat flow layers closer to the second top wall 23a in the cooling liquid are easily able to absorb heat from the second top wall 23a. However, the heat conduction efficiency between the flat flow layers is poor, and heat is not easily transferred to the inner flat flow layers in the cooling liquid, resulting in poor heat dissipation efficiency. However, since the two adjacent separators 22d are spaced apart from each other, the cooling liquid is easily able to form turbulence in the space between the two adjacent separators 22d, and the turbulence can break the flat flow layers of the cooling liquid and redistribute heat in the cooling liquid, i.e., the heat outside the cooling liquid is more easily transferred to the inside of the cooling liquid, thereby improving the heat dissipation efficiency.

[0117] The height of the separator 22d may be smaller 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 (size along the direction Z) of the separator 22d is smaller than the width (size along the direction Z) of the flow path 211, 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 separator 22d (size along direction Y) is smaller than the length of support portion 22c (size along direction Y), and the ratio of the length of separator 22d to the length of support portion 22c is in the range of 1:20 to 2:20.

[0118] Furthermore, the position of separator 22d in flow channel 211 along direction Z and along direction Y are not limited.

[0119] Optionally, as shown in FIG. 12, the bottom plates 2 are provided so as to be distributed along the width direction (parallel to the direction Z) of the battery case 10, and the fourth cavities 21a of the bottom plates 2 communicate with each other, and one of the outermost bottom plates 2 is provided with a liquid inlet 24a, and the other of the outermost bottom plates 2 is provided with a liquid outlet 24b. With this arrangement, the cooling liquid outside the bottom plate 2 can flow from the liquid inlet 24a of one of the outermost bottom plates 2 into the fourth cavity 21a of the corresponding bottom plate 2, and the fourth cavities 21a of each bottom plate 2 communicate with each other in order to form one cooling path that guides the cooling liquid to flow in one direction. The cooling liquid may pass through each fourth cavity 21a in order, or the cooling liquid may flow from the fourth cavity 21a of the other outermost bottom plate 2 to the outside of the bottom plate 2 via the corresponding liquid outlet 24b. With the above-described arrangement, the cooling liquid flows in one direction from the liquid inlet 24a to the liquid outlet 24b, making it easy to control the flow of the cooling liquid.

[0120] 11 and 14, each bottom plate 2 is provided with a sixth opening 25b communicating with the fourth cavity 21a, and the sixth openings 25b of two adjacent 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 through the sixth opening 25b into the fourth cavity 21a of the other bottom plate 2. The second top wall 23a, the first side wall 22a and the second bottom wall 23b surround and form the sixth opening 25b.

[0121] In another embodiment (not shown), the bottom plates 2 may be provided so as to be distributed along the length direction of the battery case 10 (parallel to the direction Y).

[0122] Optionally, as shown in FIG. 2, the battery case 10 further includes an inlet connection tube 6, the inside of which is connected to the inlet port 24a shown in FIG. 12, and the inlet connection tube 6 is used to connect to a corresponding external flow pipe (not shown). With this arrangement, the coolant can flow from the external flow pipe through the inlet connection tube 6 and the inlet port 24a in order into the fourth cavity 21a of the bottom plate 2. The inlet connection tube 6 is hermetically connected (for example, by welding or sealing with a sealant) to the bottom plate 2 provided with the inlet port 24a, thereby reducing the possibility of coolant leakage problems occurring between the inlet connection tube 6 and the bottom plate 2.

[0123] Optionally, as shown in FIG. 2, the battery case 10 further includes an outlet connection pipe 7, the inside of which is connected to the outlet port 24b shown in FIG. 12, and the outlet connection pipe 7 is used to connect to a corresponding external guiding pipe (not shown). With this arrangement, the coolant can flow from the fourth cavity 21a of the bottom plate 2 through the outlet port 24b and the outlet connection pipe 7 in order into the corresponding external guiding pipe. The outlet connection pipe 7 is hermetically connected (for example, by welding or sealing with a sealant) to the bottom plate 2 provided with the outlet port 24b, thereby reducing the possibility of coolant leakage problems occurring between the outlet connection pipe 7 and the bottom plate 2.

[0124] Optionally, as shown in FIG. 14, the bottom plate 2 is provided with a fifth opening 25a communicating with the fourth cavity 21a, and this arrangement makes it easy to manufacture the bottom plate 2 provided with the fifth opening 25a and the fourth cavity 21a by an extrusion molding process. As shown in FIGS. 15 and 16, the battery case 10 may further include a first closing member 8. The first closing member 8 is used to close the fifth opening 25a, and the first closing member 8 has a closing effect on the cooling liquid located in the fourth cavity 21a, reducing the possibility that the cooling liquid will leak to the outside of the bottom plate 2 via the fifth opening 25a.

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

[0126] Furthermore, a fifth opening 25a is provided on 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 a corresponding fifth opening 25a.

[0127] 15 and 16, the first closing member 8 includes at least two protrusions 81 spaced apart along the direction Z, and the protrusions 81 open and close the fifth opening 25a. The height of the protrusions 81 along the direction X is equal to the height H2 of the fourth cavity 21a along the direction X.

[0128] As shown in Figs. 15 and 16, a space 82 is provided between every two protrusions 81. In the embodiment of the present invention, the number of protrusions 81 and the space 82 is not limited. Some space 82 are fitted into the support parts 22c to connect some of the support parts 22c to some of the protrusions 81, and some space 82 are fitted into the first side walls 22a to connect some of the first side walls 22a to some of the protrusions 81. The above-mentioned installation 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] Among the fifth openings 25a, there is one that communicates with the sixth opening 25b, and there is a corresponding protrusion 81 that opens the sixth opening 25b. However, the sixth opening 25b is not blocked by the protrusion 81.

[0130] Optionally, as shown in FIG. 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 surround and form a fifth cavity 21b provided in the outermost bottom plate 2. This arrangement reduces the weight of the outermost bottom plate 2, and accordingly reduces the weight of the battery case 10, and the energy consumption required for transporting the battery case 10 is also small.

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

[0132] Optionally, as shown in FIG. 17, the outermost bottom plate 2 is further provided with a seventh opening 25c communicating with the fifth cavity 21b. As shown in FIG. 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 penetrating 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 can communicate with the fifth cavity 21b. The second closing member 9 is further provided with a second through hole 91. When the second blocking member 9 blocks the seventh opening 25c and at least a portion of the second blocking member 9 is positioned within the fifth cavity 21b, the second through hole 91 communicates with the first through hole 26, thereby forming a hole that can serve a positioning or connecting role, and by connecting the second blocking member 9 to the bottom plate 2, it can serve to improve the structural strength of the portion of the bottom plate 2 where the first through hole 26 is provided.

[0133] Optionally, as shown in FIG. 4, the outermost bottom plate 2 is integrally connected or welded to the side plates 1 .

[0134] When the outermost bottom plate 2 and the side plate 1 are integrally molded (for example, manufactured integrally using a casting process, an extrusion molding process or an injection molding process), there are advantages in 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 Fig. 19, a second aspect of the embodiment of the present invention provides a manufacturing method for a battery case. As shown in Fig. 2, the manufactured battery case 10 includes two side plates 1 and at least two bottom plates 2, each bottom plate 2 being distributed along the width direction (parallel to the direction Z) of the battery case 10, and the outermost bottom plate 2 is connected to the corresponding side plate 1. The manufacturing method for the battery case according to the embodiment of the present invention includes steps S1 and 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 connected to each other as shown in Fig. 4 are manufactured by an integral molding process, which has the advantages of reducing the number of molds to be manufactured, improving 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 molding process, or an injection molding process.

[0136] The first side walls 22a of at least two bottom plates 2 shown in FIG. 10 are welded by a friction welding process. In detail, the temperature of the first side walls 22a of the bottom plate 2 is increased by high-speed friction until at least a part of the first side walls 22a is melted, and then the melted parts of the first side walls 22a of the two bottom plates 2 are welded, and after the first side walls 22a are cooled, a welded structure is formed between the first side walls 22a of the two bottom plates 2. Since this welding process does not require auxiliary welding by other materials, 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 and the structural strength of the bottom plate 2 are the same, 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 bottom 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 bottom plates 2 melts, or the curved side wall of a high-speed rotating cylinder can be used to rub the first side walls 22a of the two bottom plates 2 simultaneously, and the melted portions of the first side walls 22a of the two bottom plates 2 can be welded. [Explanation of symbols]

[0138] 10 Battery case 1 Side Panel 1a Outer wall 1b top 1c bottom 1d U-shaped rib 11 Slide groove 111 1st top wall 112 Inner Wall 113 1st Bottom Wall 12 Hanging hole 13 First Cavity 14 First opening 15 2nd cavity 16 Second opening 17 3rd cavity 18 3rd Opening 181 First round chamfer structure 19 4th Opening 191 Second round chamfer structure 2 Bottom plate 21a 4th cavity 211 Flow Path 21b 5th cavity 22a 1st side wall 221 First chamfer 222 Second chamfer 22b 2nd side wall 22c Support part 223 3rd chamfer 224 4th chamfer 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 connection pipe 7 Outflow connection pipe 8 First blocking member 81 Protrusion 82 Spacing 9 Second blocking member 91 Second Through Hole 20 Hook 201 Bend part outer arc surface 202 Inner arc surface of bending part

Claims

1. A battery case comprising: The battery case (10) includes at least two welded bottom plates (2), each of which is provided with a fourth cavity (21a) through which a cooling liquid flows, and each of the bottom plates (2) includes a first side wall (22a) welded to an adjacent bottom plate (2), and the first side wall (22a) has a predetermined width W 2 The outermost bottom plate (2) includes a second side wall (22b) spaced apart from the first side wall (22a), and the second side wall (22b) has a predetermined width W 3 2W 2 ≧W 3 And, 7mm≦W 2 ≦10mm or 3mm≦W 3 A battery case characterized in that the thickness satisfies ≦8 mm.

2. the bottom plate (2) further includes a second top wall (23a) and a second bottom wall (23b), the second top wall (23a) is connected to the second bottom wall (23b) via the first side wall (22a) and the second side wall (22b), and the second top wall (23a), the first side wall (22a), and the second bottom wall (23b) are at least a part of a structure for surrounding and forming the fourth cavity (21a); The battery case of claim 1, characterized in that a connection point between a side of any one of the first side walls (22a) that is away from an adjacent first side wall (22a) and the corresponding second top wall (23a) includes a first chamfered portion (221), and / or a connection point between a side of any one of the first side walls (22a) that is away from an adjacent first side wall (22a) and the corresponding second bottom wall (23b) includes a second chamfered portion (222).

3. The first chamfered portion (221) has a rounded chamfer structure, and the first chamfered portion (221) has a predetermined radius R 1 and 1 mm≦R 1 ≦3 mm, and / or The second chamfered portion (222) has a rounded chamfer structure, and the second chamfered portion (222) has a predetermined radius R 2 and 1 mm≦R 2 3. The battery case according to claim 2, wherein the thickness satisfies the range of ≦3 mm.

4. The second top wall (23a) is spaced apart from the second bottom wall (23b) by a predetermined height H 2 and 5 mm≦H 2 3. The battery case according to claim 2, wherein the thickness satisfies the range of ≦8 mm.

5. The battery case according to claim 2, characterized in that 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).

6. The support portion (22c) has a plate-like structure, The battery case according to claim 5, characterized in that the fourth cavity (21a) is partitioned by the support portion (22c), thereby forming at least two parallel and communicating flow paths (211).

7. The battery case according to claim 6, characterized in that the cross-sectional shape of the flow passage (211) is rectangular, circular, semicircular, elliptical or hexagonal.

8. The battery case according to claim 6, characterized in that the bottom plate (2) further includes at least two separators (22d) positioned in the same flow path (211), the separators (22d) being parallel to the plate-shaped support portion (22c), and each of the separators (22d) positioned in the same flow path (211) is spaced apart along the flow direction of the flow path (211).

9. The bottom plates (2) are provided so as to be distributed along the width direction or length direction of the battery case (10), the fourth cavities (21a) of the bottom plates (2) are in communication with each other, one of the outermost bottom plates (2) is provided with a liquid inlet (24a), and the other outermost bottom plate (2) is provided with a liquid outlet (24b); The battery case (10) further includes a liquid inlet connection pipe (6) and a liquid outlet connection pipe (7), the inside of the liquid inlet connection pipe (6) is in communication with the liquid inlet port (24a), and the liquid inlet connection pipe (6) is hermetically connected to the bottom plate (2) in which the liquid inlet port (24a) is provided, The inside of the liquid outflow connection pipe (7) is connected to the liquid outflow port (24b), and the liquid outflow connection pipe (7) is sealed and connected to the bottom plate (2) in which the liquid outflow port (24b) is provided.

2. The battery case according to claim 1, wherein the inlet connection pipe (6) and the outlet connection pipe (7) are used to communicate with corresponding external flow ducts.

10. The battery case according to claim 1, characterized in that the bottom plate (2) is provided with a fifth opening (25a) communicating with the fourth cavity (21a), and the battery case (10) further includes a first closing member (8) closing the fifth opening (25a).

11. The battery case (10) further includes a side plate (1), and each of the bottom plates (2) is provided so as to be distributed along the width direction or length direction of the battery case (10), and the outermost bottom plate (2) is integrally formed or welded to the side plate (1); The battery case according to claim 1, characterized in that the side plate (1) is provided with an inwardly recessed slide groove (11), which is used for sliding engagement with a slide rail, and a hanging hole (12) is provided in a side wall of the side plate (1) that surrounds and forms the slide groove (11), and the hanging hole (12) is drilled by the hook (20) so that the side plate (1) is connected to the hook (20).

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

13. The battery case according to claim 12, characterized in that a first cavity (13) is further provided on the top (1b) of the side plate (1), the first cavity (13) is connected to 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).

14. The battery case of claim 13, further comprising a second cavity (15) on the side of the side plate (1) facing away from the slide groove (11), a first opening (14) being provided in the side plate (1), the first opening (14) being connected to the hanging hole (12), the second cavity (15) being connected to the slide groove (11) via the first opening (14), and the second cavity (15) being connected to the first cavity (13) via the first opening (14).

15. The battery case of claim 14, 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) also 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).

16. The battery case according to claim 15, characterized in that a third opening (18) is provided in the outer wall (1a) of the side plate (1), the third opening (18) is connected to the second opening (16), and the third opening (18) is used to retreat from the outer arc surface (201) of the bent portion of the hook (20).

17. The battery case according to claim 15, characterized in that the side plate (1) includes a letter-shaped rib portion (1d), which is partitioned to form 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 letter-shaped rib portion (1d).

18. The battery case according to claim 12, characterized in that a fourth opening (19) is provided in the outer wall (1a) of the side plate (1), the fourth opening (19) is connected to the hanging hole (12), and the fourth opening (19) is used to retreat from the inner arc surface (202) of the bent portion of the hook (20).

19. The slide groove (11) has a predetermined width W 1 and 10 mm≦W 1 ≦15 mm, and / or the slide groove (11) has a predetermined depth H 1 8mm≦H 1 The battery case according to claim 11, characterized in that the thickness satisfies ≦12 mm.

20. A method for manufacturing a battery case, comprising the steps of: The battery case (10) includes a side plate (1) and a bottom plate (2), The manufacturing method includes: manufacturing the side plate (1) and the bottom plate (2) connected to each other by an integral molding process; and welding at least two of said bottom plates (2) together by a friction welding process.

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