Battery pack

Abstract

The battery pack can also include a plurality of battery modules, a case that houses the plurality of battery modules, and a plurality of bolts that secure the plurality of battery modules to the case. The plurality of battery modules can be arranged in a matrix along a first direction and a second direction, and each of the plurality of battery modules can have a rectangular shape in a plan view along a third direction perpendicular to the first direction and the second direction. The rectangular shape can have four corners, and first, second, third, and fourth securing portions having different heights can be disposed at the four corners, respectively. In four battery modules in which the corners of the plurality of battery modules are adjacent to each other, the first, second, third, and fourth securing portions can be arranged in a superimposed manner, and the four battery modules can be secured to the case by a common bolt.

Description

Technical Field

[0001] The technology disclosed in this specification relates to battery packs. Background Technology

[0002] U.S. Patent Application Publication No. 2017 / 0365887 describes a battery pack mounted on an electric vehicle. The battery pack includes multiple battery modules arranged in a matrix, a housing housing the multiple battery modules, and multiple fastening components for securing the multiple battery modules to the housing. Summary of the Invention

[0003] Each of the aforementioned battery modules is equipped with multiple fastening components. The battery modules are secured to the housing using these multiple fastening components. However, in this case, the number of parts constituting the battery pack is large, complicating the battery pack assembly process. This specification provides a technique to reduce the number of parts constituting the battery pack and thus simplify the assembly process.

[0004] The technology disclosed in this specification is specifically embodied in a battery pack. This battery pack may also include multiple battery modules, a housing housing the multiple battery modules, and multiple bolts for fixing the multiple battery modules to the housing. Alternatively, the multiple battery modules may be arranged in a matrix along a first direction and a second direction, each battery module having a rectangular shape when viewed from above along a third direction perpendicular to the first and second directions. This rectangular shape has four corners, each with a first fixing part, a second fixing part, a third fixing part, and a fourth fixing part of different heights. In four battery modules whose corners are adjacent to each other, the first fixing parts, the second fixing parts, the third fixing parts, and the fourth fixing parts overlap and are jointly fastened to the housing by shared bolts.

[0005] In the above structure, four overlapping fixing parts of the multiple battery modules are jointly fastened to the housing by a common bolt. This structure reduces the number of bolts required to fix the multiple battery modules to the housing. Consequently, the number of bolt tightening operations is reduced, simplifying the battery pack assembly process. Attached Figure Description

[0006] The features, advantages, technical and industrial significance of embodiments of the present invention are described below with reference to the accompanying drawings, wherein the same reference numerals denote the same elements.

[0007] Figure 1 This is a top view of the battery pack.

[0008] Figure 2A This shows the structure of the battery module, and a top view of the battery module.

[0009] Figure 2BThis shows the structure of the battery module and a side view of the battery module.

[0010] Figure 3A express Figure 1 A cross-sectional view of line IIIa-IIIa.

[0011] Figure 3B express Figure 1 A cross-sectional view of line IIIb-IIIb.

[0012] Figure 3C express Figure 1 A cross-sectional view of line IIIc-IIIc.

[0013] Figure 4A express Figure 1 A cross-sectional view of the IVa-IVa line.

[0014] Figure 4B express Figure 1 A cross-sectional view of the IVb-IVb line. Detailed Implementation

[0015] In one embodiment of this technology, one of the first, second, third, and fourth fixing parts of one battery module may be overlapped with one of the first, second, third, and fourth fixing parts of another battery module on one side of the outer periphery of the plurality of battery modules, and together they may be fastened to the housing by a common bolt. With this structure, the battery pack assembly process is further simplified.

[0016] In one embodiment of this technology, on one side of the outer periphery of multiple battery modules, one of the first, second, third, and fourth fixing parts of one battery module is overlapped with one of the first, second, third, and fourth fixing parts of another battery module through a spacer, and together they are fastened to the housing by a common bolt. With this structure, even on the outer periphery where the four fixing parts do not overlap, the battery modules can be stably fixed to the housing.

[0017] In one embodiment of this technology, on one side of the outer periphery of the plurality of battery modules, the first fixing part of one battery module overlaps with one of the second, third, and fourth fixing parts of another battery module, and is jointly fastened to the first range of the housing by a common bolt. Alternatively, on the other side of the outer periphery of the plurality of battery modules, one of the second and third fixing parts of one battery module overlaps with one of the third and fourth fixing parts of another battery module, and is jointly fastened to the second range of the housing by a common bolt. In this case, the height position of the first range of the housing may differ from the height position of the second range of the housing. With this structure, even on the outer periphery where the four fixing parts do not overlap, the battery modules can be stably fixed to the housing.

[0018] In the above-described embodiments, the height of the first fixing part may be lower than the height of the second fixing part, the height of the second fixing part may be lower than the height of the third fixing part, and the height of the third fixing part may be lower than the height of the fourth fixing part. With such a structure, the structure of this technology can be actively adopted.

[0019] Referring to the accompanying drawings, the battery pack 10 of this embodiment will be described. The battery pack 10 of this embodiment can be mounted in a vehicle, for example, a battery electric vehicle (BEV). However, the vehicle is not limited to a BEV; it can also be other types of electric vehicles such as a hybrid electric vehicle (HEV) or a plug-in hybrid electric vehicle (PHEV). The battery pack 10 can supply power to the motors that drive the wheels of the vehicle.

[0020] like Figure 1 As shown, the battery pack 10 includes multiple battery modules 20, a housing 12, multiple bolts 30 for fixing the multiple battery modules 20 to the housing 12, and multiple spacers 28. Multiple battery modules 20 are housed inside the housing 12. The multiple battery modules 20 are respectively fixed to the housing 12 using multiple bolts 30.

[0021] The housing 12 is a box-shaped component with a bottom, having a bottom wall 14 and a peripheral wall 16. The bottom wall 14 is a generally rectangular flat plate component. As an example, the upper surface 14a of the bottom wall 14 has a generally rectangular shape. The peripheral wall 16 is erected from the outer periphery of the upper surface 14a of the bottom wall 14. On the upper surface 14a of the bottom wall 14, a plurality of battery modules 20 are arranged in a matrix along the length direction and the width direction perpendicular to the length direction of the upper surface 14a of the bottom wall 14.

[0022] In the accompanying drawings, the length direction of the upper surface 14a of the bottom wall 14 of the battery pack 10 is represented by the Y-axis, with one side of the length direction represented by the negative direction of the Y-axis and the other side represented by the positive direction of the Y-axis. On the upper surface 14a of the bottom wall 14 of the battery pack 10, the width direction of the battery pack 10, perpendicular to the length direction, is represented by the X-axis, with one side of the width direction represented by the negative direction of the X-axis and the other side represented by the positive direction of the X-axis. The vertical direction of the battery pack 10, perpendicular to the upper surface 14a of the bottom wall 14 (i.e., the XY plane), is represented by the Z-axis, with the upper side of the vertical direction represented by the positive direction of the Z-axis and the lower side (also referred to as the top view of the battery pack 10) represented by the negative direction of the Z-axis.

[0023] The housing 12 has a plurality of beams 18 fixed to the upper surface 14a of the bottom wall 14. The plurality of beams 18 are skeletal components of the housing 12. The plurality of beams 18 extend along the upper surface 14a of the bottom wall 14. The cross-section of each beam 18 is, for example, cylindrical or cap-shaped. Here, a cross-section refers to a section cut by a plane perpendicular to the direction in which the beam 18 extends. The plurality of beams 18 includes beams 18a, 18b, 18c, and 18d extending along the width direction of the battery pack 10 and beam 18e extending along the length direction of the battery pack 10. The plurality of beams 18a, 18b, 18c, and 18d are spaced apart along the length direction of the upper surface 14a of the bottom wall 14. Beam 18a is located at one end of the bottom wall 14 along the length direction, and beam 18d is located at the other end of the bottom wall 14 along the length direction. Beams 18b and 18c are located between beams 18a and beam 18d. The width (i.e., X-direction) dimensions of the battery packs 10 in beams 18a, 18b, and 18c are approximately equal. The width dimension of the battery pack 10 in beam 18d is larger than that in beams 18a, 18b, and 18c. Beam 18e is located at the opposite end of the width direction of the bottom wall 14. Beam 18e extends from one end of the bottom wall 14 along the length direction, passing over multiple beams 18a, 18b, and 18c, to beam 18d.

[0024] like Figure 2A , Figure 2BAs shown, each battery module 20 has multiple battery cells 22, a module housing 24, and four fixing portions 26a to 26d. Each battery cell 22 is a rechargeable battery cell. The rechargeable battery cell is, for example, a lithium-ion battery cell. Each battery cell 22 has a flat shape. Each battery cell 22 is, for example, a pouch-type (also called a laminated type) battery cell. Multiple battery cells 22 are stacked along the thickness direction of the battery cell 22 (i.e., the width direction of the battery pack 10). The module housing 24 houses the multiple battery cells 22. The module housing 24 is, for example, made of resin. The module housing 24 is generally cuboid in shape. Although not shown, the module housing 24 opens downwards. The end faces of the multiple battery cells 22 are exposed through the opening of the module housing 24.

[0025] Each module housing 24, when viewed from above, has a rectangular shape with four corners 24c. At each of the four corners 24c, there are four fixing parts 26a to 26d: a first fixing part 26a, a second fixing part 26b, a third fixing part 26c, and a fourth fixing part 26d. These four fixing parts 26a to 26d are provided for fixing each battery module 20 to the housing 12. Each of the four fixing parts 26a to 26d has a through hole extending along the thickness direction (i.e., the vertical direction) for fastening. The first fixing part 26a, the second fixing part 26b, the third fixing part 26c, and the fourth fixing part 26d are at different heights in the vertical direction (Z-direction) of the battery module 20.

[0026] As an example, such as Figure 2B As shown, the height of the first fixing part 26a is lower than the height of the second fixing part 26b. The height of the second fixing part 26b is lower than the height of the third fixing part 26c. The height of the third fixing part 26c is lower than the height of the fourth fixing part 26d. More specifically, the first fixing part 26a is located in a first range Z1 in the vertical direction (Z direction), the second fixing part 26b is located in a second range Z2 adjacent to the first range Z1 in the vertical direction, the third fixing part 26c is located in a third range Z3 adjacent to the second range Z2 in the vertical direction, and the fourth fixing part 26d is located in a fourth range Z4 adjacent to the third range Z3 in the vertical direction. The first range Z1, the second range Z2, the third range Z3, and the fourth range Z4 do not overlap with each other. As an example, the thickness dimensions (i.e., the vertical dimensions) of each of the four fixing parts 26a to 26d are approximately equal. That is, Z1 = Z2 = Z3 = Z4.

[0027] like Figure 1 , Figure 3A As shown, in the multiple battery modules 20, the corners 24c of each other (in) Figure 2A(As shown in the diagram) Of the four adjacent battery modules 20, the first fixing part 26a, the second fixing part 26b, the third fixing part 26c, and the fourth fixing part 26d are overlapped and are jointly fastened to the housing 12 by bolts 30. For example, considering... Figure 1 Four battery modules 20 located in the upper left of the page, out of the multiple battery modules 20 shown, will be described. The first fixing part 26a of the battery module 20 in the second row and second column is located on the beam 18b of the housing 12; the second fixing part 26b of the battery module 20 in the first row and second column is located on the first fixing part 26a; the third fixing part 26c of the battery module 20 in the first row and first column is located on the second fixing part 26b; and the fourth fixing part 26d of the battery module 20 in the second row and first column is located on the third fixing part 26c. Bolts 30 pass through the four fixing parts 26a to 26d overlapping the beam 18b from above and are fastened to the beam 18b.

[0028] As described above, in this embodiment, four overlapping fixing portions 26a, 26b, 26c, and 26d of the plurality of fixing portions 26a, 26b, 26c, and 26d of the plurality of battery modules 20 are jointly fastened to the housing 12 by a common bolt 30. With this structure, the number of bolts 30 required to fix the plurality of battery modules 20 to the housing 12 can be reduced. Consequently, the number of operations required to fasten the bolts 30 is also reduced, simplifying the assembly process of the battery pack 10. Here, the width and length directions of the battery pack 10 are examples of a "first direction" and a "second direction," respectively, and the downward direction in the vertical direction is an example of a "third direction."

[0029] Furthermore, on the outer periphery 21 of the plurality of battery modules 20, the first fixing part 26a, the second fixing part 26b, the third fixing part 26c, and the fourth fixing part 26d are not overlapped. Figure 1 The components are represented by dashed lines. When viewed from above, the outer perimeter 21 of the plurality of battery modules 20 has a generally rectangular shape, having a first side 21a, a second side 21b, a third side 21c, and a fourth side 21d. The first side 21a and the third side 21c are located on opposite sides of each other in the length direction of the battery pack 10. The first side 21a is located at one end of the length direction of the outer perimeter 21, and the third side 21c is located at the other end of the length direction. The second side 21b and the fourth side 21d are located between the first side 21a and the third side 21c. The second side 21b and the fourth side 21d are located on opposite sides of each other in the width direction of the battery pack 10. The fourth side 21d is located at one end of the width direction of the outer perimeter 21, and the second side 21b is located at the other end of the width direction of the outer perimeter 21. Hereinafter, refer to... Figure 1 , Figure 3A , Figure 3B , Figure 3C , Figure 4A , Figure 4BThe fixing of multiple battery modules 20 at the outer periphery 21 to the housing 12 will be explained.

[0030] like Figure 1 , Figure 3B As shown, alternatively, on the first side 21a of the outer periphery 21 of multiple battery modules 20, the first fixing part 26a of one battery module 20 and the second fixing part 26b of another battery module 20 are overlapped and jointly fastened to the beam 18a of the housing 12 by a common bolt 30. With this structure, the assembly process of the battery pack 10 is further simplified. Here, the first side 21a is an example of the "one side of the outer periphery" of this technology.

[0031] Similar to the first side 21a, as Figure 1 , Figure 4A As shown, on the second side 21b of the outer periphery 21 of the plurality of battery modules 20, the second fixing part 26b of one battery module 20 and the third fixing part 26c of another battery module 20 are overlapped and fastened together to the beam 18e of the housing 12 by a common bolt 30. The first height position Ha of the beam 18a of the housing 12 is different from the second height position He of the beam 18e of the housing 12. Specifically, the second height position He is higher than the first height position Ha. According to this structure, even on the outer periphery 21 where the four fixing parts 26a to 26d do not overlap, the battery module 20 can be stably fixed to the housing 12. Here, the first side 21a is an example of "one side of the outer periphery" of the present technology, and the second side 21b is an example of "the other side of the outer periphery" of the present technology. The beam 18a is an example of "first range" of the present technology, and the beam 18e is an example of "second range" of the present technology.

[0032] like Figure 1 , Figure 4B As shown, on the third side 21c of the outer periphery 21 of the plurality of battery modules 20, the third fixing part 26c of one battery module 20 overlaps with the fourth fixing part 26d of another battery module 20, and are jointly fastened to the beam 18d of the housing 12 by a common bolt 30. The second height position He of the beam 18e of the housing 12 is different from the third height position Hd of the beam 18d of the housing 12. Specifically, the third height position Hd is higher than the second height position He. Therefore, the relationship between the second side 21b and the third side 21c can also achieve the same effect as the relationship between the first side 21a and the second side 21b described above.

[0033] like Figure 1 , Figure 3BAs shown, on the fourth side 21d of the outer periphery 21 of the plurality of battery modules 20, the first fixing part 26a of one battery module 20 and the fourth fixing part 26d of another battery module 20 are overlapped by two spacers 28 and are jointly fastened to the beam 18e of the housing 12 by a common bolt 30. With this structure, by providing the spacers 28, the battery modules 20 can be stably fixed to the housing 12 even on the outer periphery 21 where the four fixing parts 26a to 26d do not overlap. For example, the shape of the spacers 28 is the same as the range of the fixing parts 26a and 26d that overlap in the thickness direction. Furthermore, the thickness of the spacers 28 is approximately equal to that of each of the four fixing parts 26a to 26d. Fastening holes are formed in the spacers 28 that extend through the vertical direction. In this case, for different sizes of gaps between fixing parts and between fixing parts and housing 12, the battery modules 20 can be stably fixed to the housing 12 by adjusting the number of inserted spacers 28.

[0034] In a variation, the number of spacers between the first fixing portion 26a and the fourth fixing portion 26d on the fourth side 21d is not limited to two; it can also be one. In this case, the thickness of the spacer can be larger than the thickness of each fixing portion 26a to 26d. In another variation, the battery pack 10 may not have multiple spacers 28. In this case, one side of the peripheral wall 16 of the housing 12 in the width direction may also have a protrusion extending toward the other side in the width direction (X direction). Furthermore, this protrusion can also be inserted between the first fixing portion 26a and the fourth fixing portion 26d on the fourth side 21d. That is, in this case, the protrusion can be an example of a "spacer" of the present technology.

[0035] In this embodiment, the height of the first fixing part 26a is lower than the height of the second fixing part 26b, the height of the second fixing part 26b is lower than the height of the third fixing part 26c, and the height of the third fixing part 26c is lower than the height of the fourth fixing part 26d. With this structure, the structure of this technology can be actively adopted.

[0036] The specific structures of the first fixing part 26a, the second fixing part 26b, the third fixing part 26c, and the fourth fixing part 26d are not particularly limited to the structures illustrated in the embodiments. The first fixing part 26a, the second fixing part 26b, the third fixing part 26c, and the fourth fixing part 26d may be arranged not in a counterclockwise order, but in a clockwise order. Alternatively, when viewing the battery module 20 from above, the first fixing part 26a and the second fixing part 26b may also be respectively provided at the two diagonally opposite corners 24c of the four corners 24c.

[0037] The housing 12 in the battery pack 10 may also not have multiple beams 18a, 18b, 18c. In this case, the overlapping first fixing part 26a, second fixing part 26b, third fixing part 26c and fourth fixing part 26d can also be fastened together to the bottom wall 14 of the housing 12 by bolts 30.

Claims

1. A battery pack, comprising: Multiple battery modules; Housing, housing the plurality of battery modules; and Multiple bolts are used to secure the multiple battery modules to the housing. The plurality of battery modules are arranged in a matrix along the first and second directions. The plurality of battery modules, when viewed from above along a third direction perpendicular to the first and second directions, each have a rectangular shape, and the rectangular shape has four corners. A first fixing part, a second fixing part, a third fixing part, and a fourth fixing part of different heights are respectively provided at the four corners. In the four battery modules arranged adjacent to each other at their corners, the first fixing part, the second fixing part, the third fixing part and the fourth fixing part are arranged in an overlapping manner and are fastened to the housing by a common bolt.

2. The battery pack according to claim 1, wherein, On one side of the outer periphery of the plurality of battery modules, one of the first, second, third and fourth fixing parts of one battery module is overlapped with one of the first, second, third and fourth fixing parts of another battery module, and they are jointly fastened to the housing by a common bolt.

3. The battery pack according to claim 1, wherein, On one side of the outer periphery of the plurality of battery modules, one of the first, second, third and fourth fixing parts of one battery module is overlapped with one of the first, second, third and fourth fixing parts of another battery module through a spacer, and is jointly fastened to the housing by a common bolt.

4. The battery pack according to claim 1, wherein, On one side of the outer periphery of the plurality of battery modules, a first fixing part of one battery module overlaps with one of the second, third, and fourth fixing parts of another battery module, and are jointly fastened to a first area of ​​the housing by a common bolt. On the other side of the outer periphery of the plurality of battery modules, one of the second and third fixing parts of one battery module is overlapped with one of the third and fourth fixing parts of another battery module, and they are jointly fastened to the second region of the housing by a common bolt. The height position of the first range of the housing is different from the height position of the second range of the housing.

5. The battery pack according to any one of claims 1 to 4, wherein, The height of the first fixing part is lower than the height of the second fixing part. The height of the second fixing part is lower than the height of the third fixing part. The height of the third fixing part is lower than that of the fourth fixing part.

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