Battery pack

Abstract

A battery pack (100) is provided with an elastic body (20) provided to a portion of each inner surface (12a) of a pair of lid sections (12). The pair of covers (12) is fixed to each end surface of the battery block (2) housed in the housing space of the case body (11). Gaps (GP) are respectively formed between the pair of cover parts (12) and the end edges (11a) of the opening ends of the housing main body (11). The cover part (12) comprises a flat-plate-shaped cover main body (13) and a wall part (14) protruding from the inner surface of the cover main body (13). The elastic body (20) is disposed so as to abut against the surface of the wall section (14) facing the inner surface of the case body (44), and has an inclined surface (21) that widens toward the inner surface of the cover section (12), a part of the inclined surface (21) enters the gap (GP), and a corner section (19) located between the end edge (11a) of the open end of the case body (11) and the inner surface (11b) of the case body (44) abuts against the inclined surface (21).

Description

Technical Field

[0001] This disclosure relates to battery packs. Background Technology

[0002] A battery pack is used to drive a device by connecting multiple rechargeable secondary battery cells, such as lithium-ion batteries, in series or parallel within an external housing (e.g., Patent Document 1). In such a battery pack, for example, a battery pack using... Figure 11 The exploded perspective view shows the outer casing 1110. The outer casing shown in this figure comprises a cylindrical casing body 1111 with openings on both end faces and serving as an internal receiving space, and a pair of cover portions 1112 that respectively block each end face. Furthermore, a battery block 1102 holding multiple secondary battery cells is inserted into the receiving space of the casing body 1111. With the battery block 1102 inserted from the end faces of the casing body 1111, each end face is blocked by the cover portions 1112. Each cover portion 1112 is screwed into an end face threaded hole 1108 that is opened on the end face of the casing body 1111 using an end face screw 1140.

[0003] On the other hand, the bottom surface of the housing body sometimes has a bottom threaded hole for fixing the battery block inside the receiving space. With the battery block 1102 inserted into the receiving space of the housing body 1111, the battery block 1102 is screwed in by a bottom screw 1143 that fastens to the bottom threaded hole 1109 of the housing body 1111. This configuration of the battery pack 1100 directly screws the battery block 1102 inside the housing body 1111 to the housing body 1111, thus enabling the battery block 1102 to be stably fixed to the outer housing 1110.

[0004] However, depending on the battery pack specifications, such a structure is sometimes not feasible. For example, if a threaded hole is to be formed on the end face of the casing body, the casing body needs to be made thicker. If the casing body is made of metal for strength, increasing the wall thickness will increase weight and, consequently, cost. On the other hand, to screw the bottom of the battery pack to the casing body, a threaded hole needs to be made on the bottom face of the casing body; however, such a structure makes it difficult to waterproof the outer casing. Therefore, there are also situations where the casing body and battery pack cannot be directly screwed together. Therefore, a structure is considered where the cover is directly fixed to the battery pack without opening threaded holes on the end face or bottom face of the casing body.

[0005] As an example, such as Figure 12As shown in the exploded perspective view, consider the following structure: Threaded holes 1207 are opened on each end face of the battery block 1202, which is inserted into the housing body 1211 of the outer casing 1210, and the cover 1212 is screwed in using end face screws 1240. In this structure, the end faces of the housing body 1211 and the cover 1212 are not directly fixed. Furthermore, due to manufacturing tolerances of the housing body 1211 and the battery block 1202, such as… Figure 13 As shown in the cross-sectional view, a gap will be generated at the joint interface between the housing body 1211 and the cover 1212.

[0006] The result, such as Figure 13 As indicated by the middle arrow, the amount of gap between the housing body 1211 and the cover 1212 causes a positional offset of the housing body 1211, which hinders the positioning of the battery pack when it is installed in a fixed position on the drive device, and sometimes reduces the installability.

[0007] In addition, such as Figure 14 As shown, this represents the clearance between the housing body 1211 and the cover 1212. Therefore, when the battery pack is used in an environment exposed to vibration, or when the battery pack is dropped and external stress is applied, contact may occur at the interface between the housing body 1211 and the cover 1212, potentially causing damage. Depending on the application and specifications of the battery pack, reliability and durability tests are required, including drop tests and vibration tests. In particular, when the housing body is made of metal to increase the rigidity of the outer housing, and the cover is made of resin to improve the insulation of connectors or similar components on the cover, the difference in hardness between the metal housing body and the resin cover may cause cracks to appear on the cover side.

[0008] Prior art literature

[0009] Patent documents

[0010] Patent Document 1: Japanese Patent No. 6049288 Summary of the Invention

[0011] The objective of this disclosure is to provide a battery pack that can stably fix the outer casing, cover, and battery pack. Another objective is to provide a battery pack that absorbs component tolerances and improves reliability against external forces. Furthermore, the description of these objectives and objectives does not preclude the existence of other objectives and objectives. Moreover, one aspect of this disclosure does not need to solve all of these objectives. Furthermore, based on the description, drawings, and claims of this disclosure, other objectives can be identified.

[0012] One aspect of this disclosure relates to a battery pack comprising: a battery block holding a plurality of secondary battery cells; an outer casing having: a casing body having a first opening end and a second opening end respectively and having a receiving space; a first cover portion covering the first opening end of the casing body; and a second cover portion covering the second opening end of the casing body; and a first elastic body configured to abut against the inner surface of the first cover portion, the battery block being received in the receiving space of the casing body, the first cover portion being fixed to the first end face of the battery block, and the second cover portion being fixed to the battery cell. The second end face of the block forms a first gap between the first cover portion and the housing body. The first cover portion includes a flat first cover body and a first wall portion protruding from the inner surface of the first cover body. The first elastomer is configured to abut against the surface of the first wall portion opposite to the inner surface of the housing body and has a first inclined surface that widens at the end toward the inner surface of the first cover portion. A portion of the first inclined surface enters the first gap. A first corner portion located between the end edge of the first opening end of the housing body and the inner surface of the housing body abuts against the first inclined surface.

[0013] According to one aspect of the present disclosure, the battery pack can fix the battery block and the cover, and prevent the main body housing from wobbling between the covers on both sides due to the gap generated between the main body housing and the cover by abutting the corner of the end edge of the housing body against the elastomer. Attached Figure Description

[0014] Figure 1 This is a perspective view showing the battery pack involved in Embodiment 1.

[0015] Figure 2 yes Figure 1 An exploded 3D view of the battery pack.

[0016] Figure 3 yes Figure 1 A cross-sectional view at line III-III.

[0017] Figure 4 It is shown Figure 3 Enlarged sectional view of the main part of the dashed line section.

[0018] Figure 5 It is shown Figure 2 An enlarged exploded perspective view of the cover and the elastomer.

[0019] Figure 6 Viewed from the back side Figure 5 An exploded perspective view of the cover and the elastomer.

[0020] Figure 7This shows the application of an elastomer with... Figure 6 A three-dimensional view of the state of connection between the cover and the body.

[0021] Figure 8 This is an exploded 3D view of the battery module.

[0022] Figure 9 This is a schematic cross-sectional view showing the state where the elastomer is omitted from the battery pack.

[0023] Figure 10 It is shown in Figure 9 An additional schematic cross-sectional view of the state of the elastomer is included.

[0024] Figure 11 This is an exploded perspective view of the battery pack involved in Comparative Example 1.

[0025] Figure 12 This is an exploded perspective view of the battery pack involved in Comparative Example 2.

[0026] Figure 13 yes Figure 12 A schematic cross-sectional view of the battery pack.

[0027] Figure 14 (a) is shown Figure 13 A schematic cross-sectional view of the battery pack. Figure 14 (b) is a schematic cross-sectional view showing the shell body moving to the left. Figure 14 (c) is a schematic cross-sectional view showing the state in which the main body of the shell is moved to the right.

[0028] Figure 15 yes Figure 4 Enlarged sectional view.

[0029] Figure 16 It is shown in Figure 4 Enlarged cross-sectional view of an example with a center gap of NG.

[0030] Figure 17 It is shown in Figure 4 The enlarged sectional view of the example with the largest center gap. Detailed Implementation

[0031] The manner of this disclosure can also be determined through the following structure and features.

[0032] In another aspect of the battery pack disclosed herein, as viewed from the cover portion, the first elastomer extends the first inclined surface in a widening manner at the end of the first inclined surface in the region where the first cover portion overlaps with the end edge of the first opening end of the housing body. With this structure, by having the corners of the housing body abut against the inclined surface, shaking of the housing body can be prevented.

[0033] In another embodiment of the battery pack disclosed herein, in any of the above embodiments, the first elastomer includes a flange protruding toward the inner surface of the housing body. With this structure, the battery pack is liquid-tightly sealed by the flange, achieving a waterproof structure. Furthermore, since the elastomer used to achieve the waterproof structure prevents the housing body from shaking, the shaking prevention structure can be achieved using existing components without adding new ones.

[0034] Furthermore, in another embodiment of the battery pack disclosed herein, in any of the above embodiments, the first cover body has a recess between the first wall portion and the periphery of the first cover body, and the first elastomer has a protrusion that inserts into the recess of the first cover body. With the above structure, the cover and the elastomer can be positioned and joined by inserting the protrusion into the recess. In particular, by providing the recess and protrusion in the direction of fixing the cover to the battery block, the elastomer can be stably assembled by pushing it out in a fixed direction through the cover body.

[0035] Furthermore, in another embodiment of the battery pack disclosed herein, in any of the above embodiments, the first elastomer is integrally formed with the first wall portion by two-color molding. With the above structure, the elastomer can be easily fixed to the cover portion.

[0036] Furthermore, in another embodiment of the battery pack disclosed herein, in any of the above embodiments, the first corner of the first opening end of the housing body is chamfered. This structure makes the corner that contacts the elastomer an obtuse angle, increasing the contact area and more stably preventing the housing body from shaking.

[0037] Furthermore, in another embodiment of the battery pack disclosed herein, in any of the above embodiments, the pair of covers are fixed to the end faces of the battery block by screwing. With the above structure, the covers and the battery block can be easily fixed.

[0038] Hereinafter, embodiments of the present disclosure will be described based on the accompanying drawings. However, the embodiments shown below are merely illustrative examples to concretize the technical concept of the present disclosure, and the present disclosure is not limited to them. Furthermore, this specification does not limit the components shown in the claims to the components of the embodiments. In particular, the dimensions, materials, shapes, and relative arrangements of the constituent components described in the embodiments are not intended to limit the scope of the present disclosure unless specifically stated, and are merely simple illustrative examples. In addition, the size and positional relationships of the components shown in the drawings are sometimes exaggerated for clarity. Furthermore, in the following description, the same names and reference numerals denote the same or homogeneous components, and detailed descriptions are appropriately omitted. Furthermore, the elements constituting the present disclosure can be configured such that multiple elements are composed of the same components, with one component serving as multiple elements; conversely, the function of one component can be shared by multiple components.

[0039] The battery pack disclosed herein can be used as a power source for driving mobile devices such as electric bicycles, electric trolleys, and electric mobility scooters. It can also be used as a power source for portable electrical devices such as wireless communication devices, electric cleaners, and power tools. In fixed-location energy storage applications, it can be used as a backup power source for servers, a power supply for homes, offices, and factories, and further as a power source for driving vehicles such as hybrid vehicles and electric vehicles. Hereinafter, as an embodiment of the present invention, a battery pack used as a driving power source for electric bicycles will be described.

[0040] [Implementation Method 1]

[0041] The battery pack 100 according to Embodiment 1 of this disclosure is shown in Figures 1-10 In these figures, respectively, Figure 1 This is a perspective view showing the battery pack 100 according to Embodiment 1. Figure 2 It shows Figure 1 Exploded perspective view of battery pack 100 Figure 3 It shows Figure 1 A cross-sectional view at line III-III. Figure 4 It shows the representation Figure 3 Enlarged sectional view of the main part of the dashed line section. Figure 5 It shows the representation Figure 2 Exploded perspective view of the cover 12 and the elastomer 20. Figure 6 This shows the view from the rear side. Figure 5 Exploded perspective view of the cover 12 and the elastomer 20. Figure 7 This shows the elastomer 20 and... Figure 6 A perspective view of the connected state of the cover 12. Figure 8 This shows an exploded perspective view of battery block 2. Figure 9 This is a schematic cross-sectional view showing a state where the elastomer 20 is omitted from the battery pack 100. Figure 10 It shows that in Figure 9 The figures include a schematic cross-sectional view showing the state of the elastomer 20. The battery pack 100 shown in these figures includes a battery block 2, an outer casing 10, and an elastomer 20. The battery block 2 is composed of multiple secondary battery cells 1.

[0042] (Outer casing 10)

[0043] like Figures 1-3 As shown, the outer casing 10 is configured to have an outline that extends in one direction. Here, the outer casing 10 is formed into a chamfered prism shape, but it can be made into various cross-sectional areas and shapes such as polygonal or cylindrical.

[0044] (Shell body 11)

[0045] exist Figure 2 , Figure 3 In the example, the outer casing 10 includes a casing body 11 and a pair of covers 12. The casing body 11 is formed as a cylinder with openings at both ends, with the interior serving as a receiving space. The openings at both ends are square. However, as described above, the casing body 11 can also be cylindrical, in which case the openings are circular.

[0046] The main body 11 of the housing is made of a metal component, such as aluminum or an aluminum alloy, which has excellent strength and heat dissipation. Alternatively, the outer housing may be made of a resin component with excellent insulation properties, such as polycarbonate or PC-ABS alloy.

[0047] (Cover 12)

[0048] A pair of caps 12 are formed to respectively cover the size and shape of each opening end of the housing body 11. Figure 2 , Figure 3 , Figure 4 In the example, each cover portion 12 is formed such that the inner surface 12a of the cover portion 12, that is, the side facing the opening end of the housing body 11, has a footprint that is almost equal in size to the end face of the housing body 11. In addition, on the outer surface 12b of the cover portion 12 exposed to the outside, a connector or the like for external electrical connection is provided as needed.

[0049] Each cover portion 12 has a wall portion 14 formed on its inner surface 12a. Specifically, the cover portion 12 includes a cover body 13 and a wall portion 14 extending from the inner surface 12a of the cover body 13. Figure 5 As shown, the cover body 13 is formed in a flat plate shape. A wall portion 14 is provided on the inner surface 12a of the cover body 13. Figure 6In the example shown, the wall portion 14 extends from the cover body 13 in a manner that protrudes towards the open end of the housing body 11. This wall portion 14 is preferably integrally formed with the cover body 13. Figure 7 In the example shown, it is formed as a frame shape, slightly smaller than the outer diameter of the square-shaped cover body 13. An elastomer 20 is disposed around the wall portion 14. (Example:) Figure 5 , Figure 6 As shown, with the wall portion 14 covered by the elastomer 20, the cover portion 12 is fixed to the housing body 11.

[0050] Furthermore, each cover 12 is fixed to one end face of the battery block 2 housed within the accommodating space of the main body 11. The fixing of the cover 12 to the battery block 2 is achieved using screws, rivets, welding, etc. Figure 2 , Figure 6 , Figure 7 In the example, a screw engagement using a 40mm screw was employed. Therefore, as... Figure 2 As shown, the cover body 13 has threaded holes 15 for engaging screws 40 at its four corners. Preferably, as Figure 9 As shown in the schematic cross-sectional view, a stepped portion 16 is formed around each threaded hole 15 on the outer surface 12b of the cover body 13. In the engaged state, the head 41 of the screw 40 is housed within the stepped portion 16, preventing the head 41 of the screw 40 from protruding from the outer surface 12b of the cover body 13. Additionally, on the inner surface 12a of the cover body 13, as... Figure 6 , Figure 7 As shown, cylindrical hubs 17 are formed around each threaded hole 15. Preferably, the hubs 17 and the wall portion 14 are connected by ribs 18 to increase the strength of the cover portion 12.

[0051] (Gap GP)

[0052] With each cover 12 fixed to each end face of the battery block 2, as follows: Figure 9 As shown, a gap GP is formed between the end edge of the cover 12 and the housing body 11. In the figure, for illustration, the gap GP1 on the left and the gap GP2 on the right are shown as almost equal, but in reality, they are not necessarily equal; when one gap is narrowed, the other gap becomes larger. Figure 10 As shown, these gaps are absorbed by the elastomer 20 (details to follow).

[0053] (Battery Block 2)

[0054] Battery block 2, also known as battery module or cell pack, houses multiple secondary battery cells 1. Alternatively, a battery block can be constructed from multiple sub-blocks, each housing multiple secondary battery cells. Figure 2 , Figure 8In the example, multiple cylindrical secondary battery cells 1 are accommodated and held in a horizontal position in the battery holder 5. The battery holder 5 can be constructed by dividing it into multiple parts.

[0055] (Leaderboard 7)

[0056] The battery block 2 consists of a battery holder 5, secondary battery cells 1, and a lead plate 7. The lead plate 7 is disposed on the side of the battery holder 5. The lead plate 7 connects the electrodes on the end faces of the secondary battery cells 1 to each other, thus connecting multiple secondary battery cells 1. The lead plate 7 is made of a metal plate with excellent conductivity, such as an aluminum plate, nickel plate, or copper plate. Multiple secondary battery cells 1 are connected in series and parallel via the lead plate 7. The number of series connections and the number of parallel connections can be arbitrarily set according to the required specifications. Figure 2 In the example, battery block 2 uses a total of 42 secondary battery cells 1, which are arranged in a series connection of 14 cells and a parallel connection of 3 cells, but it is not limited to this structure.

[0057] The battery block 2 is connected to the circuit board via the lead plate 7 and the busbar. The circuit board houses the charge / discharge circuit for charging and discharging the secondary battery cells 1, and the protection circuit for monitoring the voltage and temperature of the secondary battery cells 1 and cutting off the current in case of abnormalities. The circuit board is constructed of glass epoxy resin or the like. Alternatively, the battery block 2 may be equipped with a board holder 4 as a component to hold the circuit board.

[0058] The battery holder 5 is provided with multiple housings 6 that individually accommodate the secondary battery cells 1. For example, such as Figure 8 As shown, each battery holder 5 is divided into two parts along the left and right sides, and the secondary battery cell 1 is held in place by the two-part receiving cylinder 6. Such battery holder 5 is made of resin such as polycarbonate with excellent insulation properties.

[0059] (Secondary battery cell 1)

[0060] Multiple secondary battery cells 1 are arranged by battery holders 5 such that the end faces of each secondary battery cell 1 are planar. The shape of each secondary battery cell 1 can be cylindrical or square. Figure 8 In the example shown, the cylindrical secondary battery cells 1 are arranged horizontally in an alternating pattern. However, the number and arrangement of the secondary battery cells are not limited to this example; any number and arrangement can be used appropriately. For example, the cylindrical secondary battery cells can also be arranged in a matrix.

[0061] Each secondary battery cell 1 has a positive and a negative electrode. Preferably, one of the positive and negative electrodes is disposed on one end face of the secondary battery cell 1, and the other is disposed on the other end face. Figure 2In the example, the bottom of the outer can of the secondary battery cell 1 is set as the negative electrode. For such a secondary battery cell 1, known secondary batteries such as lithium-ion batteries, nickel-metal hydride batteries, and nickel-cadmium batteries can be appropriately utilized.

[0062] (Elastomer 20)

[0063] like Figure 9 As shown, with each cover 12 fixed to each end face of the battery block 2, gaps GP1 and GP2 are formed between the cover 12 (cover body 13) and the end edge 11a of the housing body 11. To fill these gaps GP1 and GP2, as follows... Figure 10 As shown, an elastic body 20 is provided on each inner surface 12a of each cover portion 12. Each elastic body 20 is configured to interact with the inner surface 11b of the wall portion 14 and the housing body 11 (see reference). Figure 9 The opposing surfaces abut each other. That is, the elastomer 20 is formed in a ring shape, covering the periphery of the wall portion 14. Figure 5 , Figure 6 In the example shown, the elastomer 20 is formed into a square shape, but it can also be formed into a polygonal shape, a ring shape, etc., depending on the shape of the wall portion 14.

[0064] (Inclined surface 21)

[0065] Each elastomer 20 forms an inclined surface 21 that widens at the end of its inner surface 12a facing the cover portion 12. For example... Figure 4 As shown, the inclined surface 21 partially enters the gap GP. As a result, the end edge of the opening end of the housing body 11 and the inner corner 19 abut against a portion of the inclined surface 21. By configuring the structure in this way, the battery block 2 and the cover 12 are fixed, and by having the corner 19 of the end edge of the housing body 11 abut against the elastomer 20, the situation where the main housing body wobbles between the two covers 12 due to the gap GP generated between the housing body 11 and the cover 12 is avoided.

[0066] Here, refer to Figures 11-14 The structure that stably maintains the main body casing will be described. Considering the battery pack 1100 involved in Comparative Example 1, Figure 11The exploded perspective view shows a structure in which a battery block 1102 is inserted into an outer casing 1110 and blocked by a cover 1112. The outer casing 1110 consists of a cylindrical casing body 1111 with openings on both end faces and an interior serving as a receiving space, and a pair of cover portions 1112 that block each end face. Furthermore, a battery block 1102 holding multiple secondary battery cells 1 is inserted into the receiving space of the casing body 1111. With the battery block 1102 inserted from the end face of the casing body 1111, each end face is blocked by the cover portions 1112. Each cover portion 1112 is screwed into an end face threaded hole 1108 that is open on the end face of the casing body 1111 using an end face screw 1140. Additionally, in Figure 11 In the example, a bottom threaded hole 1109 is provided on the bottom surface of the housing body 1111 for fixing the battery block 1102 inside the receiving space. The battery block 1102, when inserted into the receiving space of the housing body 1111, is fixed by screwing into the bottom threaded hole 1109 of the housing body 1111 with a bottom screw 1143. This battery pack 1100, with the battery block 1102 inside the housing body 1111 directly screwed into the housing body 1111, can thus stably fix the battery block 1102 to the outer housing 1110.

[0067] On the other hand, depending on the battery pack specifications, sometimes bottom-mounted screws cannot be used. For example, if a threaded hole is to be formed on the end face of the housing body, the housing body needs to be made thicker. In particular, if the housing body is made of metal for strength, increasing the wall thickness of the housing body will make it heavier and more expensive. On the other hand, in order to screw the bottom of the battery block 2 to the housing body, a threaded hole needs to be opened on the bottom face of the housing body, but if such a structure is used, it is difficult to make the outer housing waterproof. Under such circumstances, there are also cases where the housing body and the battery block cannot be directly screwed together. Therefore, the following structure is considered: without opening threaded holes on the end face and bottom face of the housing body, the cover is directly fixed to the battery block 2.

[0068] As such an example, the battery pack 1200 involved in Comparative Example 2 is shown below. Figure 12 An exploded perspective view. In this battery pack 1200, threaded holes 1207 are opened on each end face of the battery blocks 1202 inserted into the housing body 1211, and the cover 1212 is screwed in using end face screws 1240. In this structure, the end faces of the housing body 1211 and the cover 12 are not directly fixed. In addition, due to the manufacturing tolerances of the housing body 1211 and the battery blocks 2, such as Figure 13 As shown in the cross-sectional view, a gap GP will inevitably be generated at the joint interface between the housing body 1211 and the cover 1212.

[0069] The result, such as Figure 13 As indicated by the middle arrow, the positional offset of the housing body 1211, which generates the gap GP between the housing body 1211 and the cover 12, hinders the positioning of the battery pack 1200 when it is installed in a fixed position on the drive device, and sometimes reduces the installability.

[0070] In addition, such as Figure 14 As shown, this represents the state where the clearance GP between the housing body 1211 and the cover 1212 moves. Therefore, when the battery pack 1200 is used in an environment exposed to vibration, or when the battery pack 1200 is dropped and external stress is applied, contact may occur at the interface between the housing body 1211 and the cover 1212, resulting in damage. Depending on the application and specifications of the battery pack, reliability and durability tests are required, such as drop tests and vibration tests. In particular, when the housing body is made of metal to improve the rigidity of the outer housing, and the cover is made of resin to improve the insulation of connectors provided in the cover, the hardness of the metal housing body and the resin cover is different, which may cause cracks to occur on the cover side.

[0071] In contrast, in the battery pack 100 according to this embodiment, by means of... Figure 10 The elastomer 20 is configured as shown to suppress the generation of... Figure 9 Such a gap is caused by GP-induced shaking. Specifically, as Figure 15 As shown, an elastic body 20 is disposed on the outer side of each wall portion 14, such that a portion of the inclined surface 21 formed on the elastic body 20, which widens at its end towards the inner surface 12a of the cover portion 12, enters the gap GP between the opening end edge of the cover body 13 and the housing body 11. With this arrangement, the opening end edge of the housing body 11 and the inner corner 19 abut against a portion of the inclined surface 21. As a result, the housing body 11 is supported from at least one side, either left or right, by the inclined surface 21 entering the gap GP between the left and right cover portions 12 and the housing body 11.

[0072] Here, the size of the gap GP varies depending on component tolerances, etc. Therefore, the length of the inclined surface 21 is designed so that even at the maximum conceivable gap GP, the corner 19 can abut against the inclined surface 21 and fill the gap GP. In other words, the dimensions of the inclined surface 21 are designed to avoid... Figure 16 The corner portion 19 shown does not come into contact with the inclined surface 21 and thus cannot block the gap GP. Furthermore, the angle of the inclined surface 21 is preferably set to 35° to 55° relative to the wall portion 14, and more preferably to around 45°.

[0073] like Figure 17As shown, the inclined surface 21 of the elastomer 20 will elastically deform even when it comes into contact with the corner 19, supporting the housing body 11 from at least one side, either left or right. Therefore, the battery pack 100 achieves improved reliability against external forces, independent of manufacturing tolerances of the housing body 11, cover 12, etc. In other words, it suppresses... Figure 14 The situation where the main body of the housing moves left and right between a pair of covers, as shown, can prevent damage to the contact surface between the main body of the housing and the covers, thereby improving the reliability of the outer housing.

[0074] In the case where the battery pack 100 according to this embodiment has a cover 12 fixed on each end face of the battery block 2 and an elastic body 20 is provided on each of the left and right pairs of cover 12, the case body 11 can be suppressed from swaying left and right between the pair of cover 12 by the elastic bodies 20 of each pair of cover 12 in the left and right directions, which is beneficial to enhance the effect of suppressing left and right swaying.

[0075] Viewed from the cover 12, the elastomer 20 causes the inclined surface 21 to extend wider at the end of the region where the end edge of the cover 12 overlaps with the opening end of the housing body 11. By configuring the structure in such a way that the corner 19 of the housing body 11 necessarily abuts against the inclined surface 21, it is possible to prevent the housing body 11 from shaking.

[0076] The elastomer 20 is composed of elastic components. Materials constituting the elastomer 20 can include, for example, thermoplastic elastomers and synthetic rubber.

[0077] Alternatively, the elastomer 20 can also be integrally formed with the wall portion 14 through two-color molding. Through two-color molding, the wall portion 14 and the elastomer 20 of different materials can be alternately molded in one cycle. By making one molded article with two types of resin, it is easy to obtain the cover portion 12 that pre-fixes the elastomer 20 to the wall portion 14.

[0078] (Flange 22)

[0079] Additionally, the elastomer 20 is provided with a flange portion 22 protruding into the inner surface 12a of the housing body 11. For example... Figure 15As shown, the height of the flange 22 is designed to be slightly larger than the distance between the elastic portion and the inner surface of the housing body 11. Therefore, the leading edge of the flange 22 abuts against the inner surface of the housing and deforms elastically, liquid-tightly sealing the area between the wall portion 14 and the housing body 11, thus achieving a waterproof structure for the battery pack 100. Furthermore, since the elastic body 20 used to achieve the waterproof structure can prevent the housing body 11 from shaking, the shaking prevention structure can be achieved using existing components without adding new ones. In other words, by changing the shape of the gasket used to achieve the waterproof structure, in addition to the waterproof structure, a shaking prevention function for the housing body can be added. Through the reuse of components, reliability can be improved inexpensively with a simple structure.

[0080] exist Figure 15 In the example, the flange 22 is formed in two layers, which improves water resistance. However, depending on the required water resistance, the flange 22 can also be made in one or three layers.

[0081] Alternatively, a recess 13a may be formed on the inner surface 12a of the cover body 13. For example... Figure 6 , Figure 15 As shown, the recess 13a is annular between the portion of the wall portion 14 provided on the inner surface 12a of the cover body 13 and the periphery, and forms a ring along the periphery terrain.

[0082] (convex part 23)

[0083] On the other hand, such as Figure 4 As shown, the elastomer 20 has a protrusion 23 on the surface opposite to the inner surface 12a, which is used to insert into the recess 13a. With this structure, the cover 12 and the elastomer 20 can be positioned and joined by inserting the protrusion 23 into the recess 13a. Furthermore, by providing the recess 13a and the protrusion 23 in the direction that fixes and presses the cover 12 against the battery block 2, the elastomer 20 can be stably assembled by pushing it out in a fixed direction through the cover body 13.

[0084] In addition, the corner 19 of the opening end of the housing body 11 is chamfered. By setting the structure in this way, the corner 19 that contacts the elastomer 20 is obtuse, and the surface pressure of the contact portion is obtained, which can more stably prevent the housing body 11 from shaking.

[0085] The examples above illustrate the use of battery packs as a power source for electric bicycles. However, this disclosure is not limited to this; it can also be used for other purposes, such as assembling battery packs into electrical devices to power them. Examples of electrical devices include electric vehicles, electric trolleys, and other mobile or portable electrical devices. In such devices, when the remaining capacity of the battery pack is low or the battery pack deteriorates over time, the battery pack can be replaced to continue using the electrical device. However, this disclosure does not limit battery packs to replaceable types that primarily house individual secondary battery cells; it can also be applied to types where secondary battery cells are housed within the casing of the electrical device. In this disclosure, a battery pack is defined as any type that houses individual secondary battery cells within its casing, including types where secondary battery cells for driving are built into the casing of the electrical device itself. That is, this disclosure is not limited to replaceable battery packs; it can also be applied to electrical devices with built-in secondary battery cells.

[0086] Industrial availability

[0087] In addition to electric bicycles, the battery packs involved in this invention are also suitable for use as a power source for driving mobile devices such as electric trolleys and electric mobility scooters. Furthermore, they are suitable for use as a power source for wireless communication devices, portable electrical devices such as electric cleaners and power tools, or as a backup power source for servers, or as a fixed-installation energy storage device for home, office, or factory use.

[0088] -Explanation of Figure Markers-

[0089] 100 battery pack

[0090] 1. Secondary battery cell

[0091] 2 battery blocks

[0092] 5 Battery retainer

[0093] 6. Receiving cylinder

[0094] 7. Leadspan

[0095] 10. External housing

[0096] 11. Main body of the shell

[0097] 11a End edge

[0098] 11b Inner Surface

[0099] 12 cover

[0100] 12a Inner Surface

[0101] 12b outer surface

[0102] 13. Main body of the cover

[0103] 13a recess

[0104] 14. Wall section

[0105] 15 Threaded holes

[0106] 16 Steps

[0107] 17-inch hub

[0108] 18 ribs

[0109] 19 corner

[0110] 20 Elastomers

[0111] 21 Inclined surface

[0112] 22 Flange portion

[0113] 23 convex part

[0114] 40 screws

[0115] 41. Head

[0116] 1100 and 1200 battery packs

[0117] 1102 and 1202 battery blocks

[0118] 1108 End face threaded hole

[0119] 1109 Bottom surface threaded hole

[0120] 1110, 1210 outer casing

[0121] 1111, 1211 Main body of the shell

[0122] 1112, 1212 cover

[0123] 1140 end face screw

[0124] 1143 Bottom screw

[0125] 1240 end face screw

[0126] GP gap

[0127] The gap on the left side of GP1

[0128] The gap on the right side of GP2.

Claims

1. A battery pack, comprising: Battery block, holding multiple secondary battery cells; An outer casing includes: a casing body having openings on a first end face and a second end face, respectively, providing a receiving space; a first cover covering the first opening of the casing body; and a second cover covering the second opening of the casing body; and The first elastic body is disposed on the inner surface of the first cover portion. The battery pack is housed in the receiving space of the housing body. The first cover is fixed to the first end face of the battery block. The second cover is fixed to the second end face of the battery block. A first gap is formed between the first cover and the housing body. The first cover portion includes: The first cover body is flat; and The first wall portion protrudes from the inner surface of the first cover body. The first elastomer is configured to abut against the surface of the first wall portion opposite the inner surface of the housing body. The first elastomer has a first inclined surface that widens at the end of the inner surface facing the first cover portion. A portion of the first inclined surface enters the first gap. The first corner of the housing body, located between the end edge of the first opening end of the housing body and the inner surface of the housing body, abuts against the first inclined surface.

2. The battery pack according to claim 1, wherein, Viewed from the cover, the first elastomer extends the first inclined surface in a widening manner at the end of the first inclined surface in the region where the first cover overlaps with the end edge of the first opening end of the housing body.

3. The battery pack according to claim 1, wherein, The first elastomer further includes a flange that protrudes toward the inner surface of the housing body.

4. The battery pack according to claim 1, wherein, The first cover body has a recess between the first wall portion and the periphery of the first cover body. The first elastomer has a protrusion that is inserted into the recess of the first cover body.

5. The battery pack according to any one of claims 1 to 4, wherein, The first elastomer is integrally formed with the first wall portion by two-color molding.

6. The battery pack according to any one of claims 1 to 4, wherein, The first corner of the first opening end of the housing body is chamfered.

7. The battery pack according to any one of claims 1 to 4, wherein, The first cover is fixed to the first end face of the battery block by screwing. The second cover is fixed to the second end face of the battery block by screwing.

8. The battery pack according to any one of claims 1 to 4, wherein, The battery pack further includes: a second elastomer disposed on the inner surface of the second cover portion. A second gap is formed between the second cover and the housing body. The second cover portion includes: The flat second cover body; and The second wall portion protrudes from the inner surface of the second cover body. The second elastomer is configured to abut against the surface of the second wall portion opposite the inner surface of the housing body. The second elastomer has a second inclined surface that widens at the end of the inner surface facing the second cover portion. A portion of the second inclined surface enters the second gap. The second corner of the housing body, located between the end edge of the second opening end of the housing body and the inner surface of the housing body, abuts against the second inclined surface.

Images