Battery pack

Abstract

The present invention relates to a battery pack. The battery pack can include a battery cell, a cooler located below the battery cell and having a cooling channel, and a protective panel covering the cooler from the bottom. A groove extending along the cooling channel can be provided to a lower surface of the cooler. At least one reinforcing rib protruding toward the cooler can be provided to an upper surface of the protective panel. The reinforcing rib can be accommodated in the groove of the cooler.

Description

Technical Field

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

[0002] Japanese Unexamined Patent Application Publication No. 2023-046671 (JP 2023-046671 A) describes a battery pack installed in an electric vehicle. The battery pack includes individual battery cells, a cooler disposed below the individual battery cells, and a protective panel covering the cooler from the bottom. Summary of the Invention

[0003] Typically, the battery pack is located below the floor of an electric vehicle. In this case, the protective panel is exposed beneath the electric vehicle. To increase the rigidity of the protective panel, it is conceivable to provide reinforcing ribs. However, when reinforcing ribs are added to the protective panel, the substantial thickness of the protective panel increases. As a result, the dimensions of the battery pack in the vertical direction also increase. This specification provides a technique for increasing the rigidity of the protective panel while minimizing the increase in the size of the battery pack.

[0004] The technology disclosed in this specification is embodied in a battery pack. The battery pack may include individual battery cells, a cooler located below the battery cells and having cooling channels, and a protective panel covering the cooler from the bottom. A groove extending along the cooling channels may be provided on the lower surface of the cooler. At least one reinforcing rib protruding toward the cooler may be provided on the upper surface of the protective panel. The reinforcing rib may be accommodated in the groove of the cooler.

[0005] In the above configuration, the reinforcing ribs provided to the protective panel are accommodated in the recesses of the cooler. Therefore, even when the substantial thickness of the protective panel is increased by providing reinforcing ribs to the protective panel, the increase in the vertical dimension of the battery pack can be suppressed. Attached Figure Description

[0006] The features, advantages, and technical and industrial significance of exemplary embodiments of the present invention will now be described with reference to the accompanying drawings, in which the same symbols denote the same elements, and wherein: Figure 1 The configuration of the electric vehicle is shown schematically; Figure 2 The battery pack configuration is shown; Figure 3 The configuration of the battery module is shown; Figure 4 It is along Figure 2 A cross-sectional view taken from line IV-IV in the diagram; Figure 5 The configuration of the bottom wall of the housing is shown; and Figure 6The configuration of the protection panel is shown. Detailed Implementation

[0007] In one embodiment of this technology, at least one engaging rib protruding toward the cooler can be provided to the protective panel, and the protective panel can be bonded to the cooler at the engaging rib via an adhesive. In this case, a reinforcing rib can extend along a first direction on the upper surface of the protective panel, and the engaging rib can extend along a second direction intersecting the first direction on the upper surface of the protective panel. With this configuration, the rigidity of the protective panel is effectively increased by the combination of reinforcing ribs and engaging ribs extending in different directions.

[0008] In the above embodiments, on the upper surface of the protective panel, the width of the reinforcing rib perpendicular to the first direction can be smaller than the width of the connecting rib perpendicular to the second direction. By setting the relatively large width of the connecting rib, the protective panel can be securely attached to the cooler. By setting the relatively small width of the reinforcing rib, the reinforcing rib can be easily accommodated in the groove of the cooler.

[0009] As an alternative to or in addition to the above configuration, the protruding height of the reinforcing ribs on the upper surface of the protective panel can be greater than that of the connecting ribs. Since the reinforcing ribs are housed within recesses in the cooler, their height can be greater than that of the connecting ribs. Increasing the height of the reinforcing ribs increases the rigidity of the protective panel.

[0010] In one embodiment of this technology, the at least one joining rib may include a first joining rib, a second joining rib, and a third joining rib arranged along a first direction. In this case, the at least one reinforcing rib may include a plurality of first reinforcing ribs positioned between the first and second joining ribs and arranged along a second direction, and a plurality of second reinforcing ribs positioned between the second and third joining ribs and arranged along the second direction. With this configuration, the rigidity of the protective panel is more effectively increased because the reinforcing ribs are arranged between two adjacent joining ribs.

[0011] A battery pack 20 according to an embodiment will be described with reference to the accompanying drawings. The battery pack 20 according to this embodiment is mounted on an electric vehicle 10. (Refer to...) Figure 1 The following describes electric vehicle 10. Electric vehicle 10 is a battery electric vehicle (BEV). However, electric vehicle 10 is not limited to BEV and can be another type of electric vehicle, such as a hybrid electric vehicle (HEV) or a plug-in hybrid electric vehicle (PHEV).

[0012] The orientation of the battery pack 20 in this specification and accompanying drawings refers to the orientation of the battery pack 20 when it is mounted on the electric vehicle 10, and corresponds to the orientation within the electric vehicle 10. In the drawings, direction FR indicates forward in the longitudinal direction of the electric vehicle 10, and the negative direction RR relative to direction FR indicates backward in the longitudinal direction of the electric vehicle 10. Direction LH indicates left in the left-right direction of the electric vehicle 10, and the negative direction RH relative to direction LH indicates right in the left-right direction of the electric vehicle 10. Direction UP indicates upward in the vertical direction of the electric vehicle 10, and the negative direction DW relative to direction UP indicates downward in the vertical direction of the electric vehicle 10.

[0013] The electric vehicle 10 includes a battery pack 20, a body 12, multiple wheels 14 and 16, and a motor unit 18. The electric vehicle 10 is an electric vehicle. The body 12 is made of a metal such as a steel-based material or an aluminum-based material. The wheels 14 and 16 support the body 12. The wheels 14 and 16 include a pair of front wheels 14 located at the front of the body 12 and a pair of rear wheels 16 located at the rear of the body 12. The front wheels 14 are located on the left and right sides of the body 12. The rear wheels 16 are located on the left and right sides of the body 12. The body 12 has an interior passenger compartment 12c. The passenger compartment 12c is configured to accommodate occupants. The body 12 includes a floor panel 12p. The floor panel 12p defines the floor of the passenger compartment 12c.

[0014] Motor unit 18 includes a drive motor for driving front wheels 14. However, motor unit 18 is not limited to driving front wheels 14, but can drive at least one of wheels 14 and 16. Motor unit 18 may be located at the front of the carriage 12c.

[0015] The battery pack 20 is electrically connected to the motor unit 18 via, for example, a power conversion device (not shown). The battery pack 20 supplies power to the motor unit 18 to drive the wheels 14, 16. The battery pack 20 is located at the lower part of the vehicle body 12. Specifically, the battery pack 20 is located below the floor panel 12p of the vehicle body 12. The battery pack 20 is supported by the vehicle body 12. For example, the battery pack 20 can be fixed to the right side beam and the left side beam of the vehicle body 12.

[0016] Reference Figures 2 to 5 Detailed description of battery pack 20. (e.g.) Figure 2 As shown, the battery pack 20 is a thin battery pack with a smaller dimension in the vertical direction. The battery pack 20 has a flat cuboid shape. The dimension of the battery pack 20 in the vertical direction is smaller than the dimension of the battery pack 20 in the horizontal direction, and the dimension of the battery pack 20 in the horizontal direction is smaller than the dimension of the battery pack 20 in the front-back direction.

[0017] The battery pack 20 includes multiple battery modules 50, a housing 22, a protective panel 38, and a cover 44. The housing 22 houses the battery modules 50.

[0018] like Figure 3 As shown, the battery module 50 includes a plurality of battery cells 52. In a variant, the battery module 50 may include only one battery cell 52. Each of the battery cells 52 is a rechargeable and dischargeable secondary battery cell. The secondary battery cell is, for example, a lithium-ion battery cell. The battery module 50 has an opening 51 in its lower surface 50b. On the lower surface 50b of the battery module 50, the end faces of the battery cells 52 are exposed through the opening 51. Each battery cell 52 is a pouch cell (also known as a "laminated cell") cell. Each battery cell 52 has a flat shape. The battery cells 52 are oriented along the thickness direction ( Figure 3 The battery cells 52 are stacked in the left-right direction. The individual battery cells 52 are joined by bonding strips 54 and compressed simultaneously in the stacking direction. The battery module 50 includes components in the longitudinal direction of each battery cell 52. Figure 3 The battery module 50 includes a cathode terminal 60a and an anode terminal 60b at one end (in the front-to-back direction). The battery module 50 includes a module housing 56 that houses the battery cells 52. An opening 51 is defined by the module housing 56.

[0019] The casing 22 is made of a metal such as aluminum. Figure 2 As shown, the housing 22 includes a housing body 24 and a plurality of beams 34a, 34b, 34c, 36. The housing body 24 includes a bottom wall 26 located below the battery module 50 and an outer peripheral wall 32 rising upright from the outer peripheral edge 26e of the bottom wall 26. The outer peripheral wall 32 extends around the outer peripheral edge 26e of the bottom wall 26. The housing body 24 has an upwardly opening 25. The opening 25 is defined by the inner surface of the outer peripheral wall 32. The cover 44 is a plate-like member and is configured to close the opening 25 of the housing body 24 from the top. The cover 44 is made of a metal such as aluminum.

[0020] Beams 34a, 34b, 34c, and 36 are skeletal components of the shell 22. Beams 34a, 34b, 34c, and 36 extend along the upper surface 26a of the bottom wall 26. Beams 34a, 34b, 34c, and 36 comprise multiple first beams 34a, 34b, and 34c and one second beam 36. The first beams 34a, 34b, and 34c extend laterally across the upper surface 26a of the bottom wall 26. Each of the first beams 34a, 34b, and 34c extends from the left side of the outer peripheral wall 32 to the right side of the outer peripheral wall 32. The second beam 36 extends longitudinally across the upper surface 26a of the bottom wall 26. The first beams 34a, 34b, and 34c are spaced apart in the front-rear direction. The second beam 36 is located at the center of the bottom wall 26 in the left-right direction. The first beams 34a, 34b, and 34c (hereinafter referred to as "first beams 34") are orthogonal to the second beam 36. Figure 2As shown, the first beam 34 extends across the second beam 36. The first beam 34 and the second beam 36 are configured to be assembled together. Beams 34 and 36 are fixed to the upper surface 26a of the bottom wall 26.

[0021] like Figure 4 As shown, the bottom wall 26 includes an upper panel 28 and a lower panel 30 facing each other in the vertical direction. Each of the upper panel 28 and the lower panel 30 is a plate-like member. The upper panel 28 and the lower panel 30 are joined together. A channel 40 along which coolant flows is defined between the upper panel 28 and the lower panel 30. The bottom wall 26 of the housing 22 serves as a cooler for the battery module 50. The lower surface of the lower panel 30 (i.e., the lower surface 26b of the bottom wall 26) has a plurality of grooves 31 recessed toward the upper panel 28. The grooves 31 extend along the channel 40. The area of ​​the upper surface 30a of the lower panel 30 that protrudes upward due to the grooves 31 contacts the lower surface 28b of the upper panel 28. Thus, the channel 40 is formed between the lower surface 28b of the upper panel 28 and the upper surface 30a of the lower panel 30. The flow of coolant through the channel 40 regulates the temperature of the battery module 50 disposed on the upper surface 26a of the bottom wall 26.

[0022] Figure 5 The shell 22 is shown as viewed from the bottom. Figure 5 In the diagram, the channel 40 formed inside the bottom wall 26 is indicated by a dashed line. Figure 5 In the diagram, beams 34 and 36, fixed to the upper surface 26a of the bottom wall 26, are shown by dashed lines. For example... Figure 5 As shown, a supply port 40a through which coolant is supplied to the channel 40 and a discharge port 40b through which coolant is discharged from the channel 40 are located at the front end 26f of the bottom wall 26. The channel 40 extends meanderingly from the supply port 40a to the discharge port 40b.

[0023] like Figure 4 and Figure 6 As shown, a protective panel 38 is disposed on the lower surface 26b of the bottom wall 26. The protective panel 38 is a plate-shaped member with a predetermined profile. The protective panel 38 is a protective member that covers the bottom wall 26 from the bottom. The protective panel 38 is located at the lowest point of the battery pack 20 and is exposed to the road surface. By providing the protective panel 38, the impact of the road surface or other factors on the battery module 50 (e.g., the impact of collisions or rain) is reduced. The protective panel 38 is bonded to the lower surface 26b of the bottom wall 26 via an adhesive 42. The protective panel 38 is made of resin.

[0024] The upper surface 37 of the protective panel 38 includes a plurality of engaging ribs 37a, 37b and a plurality of reinforcing ribs 37c. The engaging ribs 37a, 37b and the reinforcing ribs 37c each protrude toward the bottom wall 26. The engaging ribs 37a, 37b are provided to engage the bottom wall 26 to the protective panel 38. The reinforcing ribs 37c are provided to increase the rigidity of the protective panel 38.

[0025] Figure 6 This is a bottom view of the battery pack 20, showing the lower surface 39 of the protective panel 38. The joining ribs 37a, 37b and reinforcing ribs 37c are indicated by dashed lines. Figure 6 In the middle, beams 34 and 36 are fixed to the upper surface 26a of the bottom wall 26, as shown in the figure. Figure 5 As shown by the dashed lines, the protective panel 38 has a constant thickness. That is, the area enclosed by the dashed lines on the lower surface 39 of the protective panel 38 is recessed towards the far side of the drawing relative to the main area 39m of the lower surface 39 of the protective panel 38. However, in a variant, the area enclosed by the dashed lines on the lower surface 39 does not need to be recessed. In this case, the thickness of the protective panel 38 can be increased within the range of providing the joining ribs 37a, 37b and the reinforcing ribs 37c.

[0026] The joining ribs 37a and 37b are bonded to the base wall 26 via adhesive 42. The joining ribs 37a and 37b extend along the front-rear direction on the upper surface 37 of the protective panel 38. The joining ribs 37a and 37b include a plurality of first joining ribs 37a and a plurality of second joining ribs 37b. The first joining ribs 37a and second joining ribs 37b are arranged alternately in the front-rear direction. In one example, the dimension of the second joining rib 37b in the front-rear direction is smaller than the dimension of the first joining rib 37a in the front-rear direction.

[0027] There are no particular restrictions on the specific arrangement of the connecting ribs 37a and 37b. For example, the first connecting ribs 37a are arranged in four rows and three columns. The first connecting ribs 37a are arranged so as not to overlap with the first beam 34 of the housing 22. Among the plurality of first connecting ribs 37a, the first connecting ribs 37a located at the center in the left-right direction are arranged at the position where they overlap with the second beam 36 of the housing 22. The second connecting ribs 37b are arranged in three rows and two columns. The second connecting ribs 37b are positioned between the first connecting ribs 37a in the left-right direction and are arranged at the position where they overlap with the first beam 34 of the housing 22.

[0028] Reinforcing ribs 37c extend on the upper surface 37 of the protective panel 38 in a left-right direction intersecting the front-back directions of the connecting ribs 37a and 37b. Each reinforcing rib 37c is positioned between two adjacent connecting ribs 37a and 37b. Each reinforcing rib 37c is received in a corresponding groove 31 in the bottom wall 26. The width dimension Wc of each reinforcing rib 37c is smaller than the width dimension Wa of each first connecting rib 37a and the width dimension Wb of each second connecting rib 37b. The width dimension refers to the dimension in a plane perpendicular to the direction in which the ribs 37a, 37b, and 37c extend on the upper surface 37 of the protective panel 38. The protrusion height dimension Hc of each reinforcing rib 37c is larger than the protrusion height dimension Ha of each first connecting rib 37a. The height dimension refers to the dimension of each of the ribs 37a, 37b, and 37c that protrude vertically from the main area 37m of the upper surface 37 of the protective panel 38. In the protective panel 38, the main region 37m of the upper surface 37 is opposite to the main region 39m of the lower surface 39. The height dimension Ha of the first connecting rib 37a and the height dimension of the second connecting rib are substantially equal to each other. However, the height dimensions Ha of the first connecting rib 37a and the second connecting rib can be different from each other. In this case, the protruding height dimension Hc of each reinforcing rib 37c can be greater than both the height dimensions Ha of the first connecting rib 37a and the height dimensions of the second connecting rib. The portion of each reinforcing rib 37c that is higher than each of the connecting ribs 37a and 37b is accommodated in a corresponding groove 31. In a variant, the protective panel 38 does not need to have connecting ribs 37a and 37b. In this case, the reinforcing ribs 37c can be accommodated substantially completely in the groove 31.

[0029] As described above, the battery pack 20 of this embodiment is disposed below the floor panel 12p of the electric vehicle 10. In this case, the protective panel 38 is exposed below the electric vehicle 10. To increase the rigidity of the protective panel 38, it is conceivable to provide reinforcing ribs to the protective panel 38. However, when reinforcing ribs are provided to the protective panel 38, the substantial thickness of the protective panel 38 increases. Therefore, the dimensions of the battery pack 20 in the vertical direction can also be increased.

[0030] In this embodiment, the reinforcing ribs 37c provided to the protective panel 38 are received in a groove 31 extending along the channel 40 in the bottom wall 26. Therefore, even when the substantial thickness of the protective panel 38 is increased by providing the reinforcing ribs 37c to the protective panel 38, the increase in the vertical dimension of the battery pack 20 can be suppressed. The bottom wall 26 is an example of a "cooler" according to the present invention, and the channel 40 is an example of a "cooling channel" according to the present invention.

[0031] In this embodiment, reinforcing ribs 37c extend along the left-right direction on the upper surface 37 of the protective panel 38, and connecting ribs 37a and 37b extend along the front-back direction on the upper surface 37 of the protective panel 38. With this configuration, the rigidity of the protective panel 38 is effectively increased by the combination of the reinforcing ribs 37c and connecting ribs 37a and 37b extending in different directions. Connecting ribs 37a and 37b are examples of "connecting ribs" according to the present invention. The left-right direction is an example of a "first direction" according to the present invention, and the front-back direction is an example of a "second direction" according to the present invention.

[0032] In this embodiment, the width dimension Wc of each reinforcing rib 37c is smaller than the width dimensions Wa and Wb of the connecting ribs 37a and 37b. By setting the relatively large width dimensions Wa and Wb of the connecting ribs 37a and 37b, the protective panel 38 can be securely attached to the bottom wall 26. By setting the relatively small width dimension Wc of each reinforcing rib 37c, each reinforcing rib 37c can be easily accommodated in the groove 31 in the bottom wall 26.

[0033] In this embodiment, the height dimension Hc of each reinforcing rib 37c is greater than the height dimension Ha of each of the connecting ribs 37a and 37b. In this case, each reinforcing rib 37c is accommodated in a corresponding groove 31 in the bottom wall 26. Therefore, the height dimension Hc of each reinforcing rib 37c can be greater than the height dimension Ha of each of the connecting ribs 37a and 37b. When the height dimension Hc of each reinforcing rib 37c increases, the rigidity of the protective panel 38 can be increased.

[0034] In this embodiment, a reinforcing rib 37c is disposed between two adjacent first connecting ribs 37a among a plurality of first connecting ribs 37a arranged in a left-right direction. Specifically, a reinforcing rib 37c is disposed between the first connecting rib 37a located at the left end and the first connecting rib 37a located in the middle between the left and right ends among three first connecting ribs 37a arranged in a row in a left-right direction. Furthermore, a reinforcing rib 37c is disposed between the first connecting rib 37a located at the right end and the first connecting rib 37a located in the middle between the first connecting ribs 37a located at the left and right ends among three first connecting ribs arranged in a row in a left-right direction. With this configuration, the rigidity of the protective panel is more effectively increased because the reinforcing rib is disposed between two adjacent connecting ribs. The first connecting ribs 37a located at the left, middle, and right ends arranged in a row in a left-right direction are examples of "first connecting ribs," "second connecting ribs," and "third connecting ribs" according to the present invention. The reinforcing rib 37c between the first joining rib 37a at the left end and the first joining rib 37a at the middle is an example of a "first reinforcing rib", and the reinforcing rib 37c between the first joining rib 37a at the middle and the first joining rib 37a at the right end is an example of a "second reinforcing rib". However, the number of reinforcing ribs 37c is not limited to multiple, and can be one.

[0035] In this embodiment, the relationship between the first joining rib 37a and the reinforcing rib 37c can also be applied to the second joining rib 37b and the reinforcing rib 37c. That is, the reinforcing rib 37c is disposed between two adjacent second joining ribs 37b among a plurality of second joining ribs 37b arranged in the front-rear direction. Specifically, the reinforcing rib 37c is disposed between the second joining rib 37b at the front end of a row of three second joining ribs 37b arranged in the front-rear direction and the second joining rib 37b at the middle position between the second joining rib 37b at the front end and the second joining rib 37b at the rear end of a row of three second joining ribs 37b arranged in the front-rear direction and the second joining rib 37b at the middle position between the second joining rib 37b at the front end and the second joining rib 37b at the rear end of a row of three second joining ribs 37b arranged in the front-rear direction. The second joining ribs 37b at the front end, middle position, and rear end of a row arranged in the front-rear direction are examples of the "first joining rib," "second joining rib," and "third joining rib" according to the present technology. The reinforcing rib 37c between the second joint rib 37b at the front end and the second joint rib 37b at the middle is an example of a "first reinforcing rib", and the reinforcing rib 37c between the second joint rib 37b at the middle and the second joint rib 37b at the rear end is an example of a "second reinforcing rib".

[0036] In one variation, the protective panel 38 does not need to have both the first engaging rib 37a and the second engaging rib 37b. For example, the protective panel 38 may have either the first engaging rib 37a or the second engaging rib 37b. In another variation, the number of engaging ribs 37a and 37b is not limited to multiple, and may be a single one.

Claims

1. A battery pack, comprising: Battery cell; A cooler located below the battery cell and having a cooling channel; as well as A protective panel covers the cooler from the bottom, wherein: A groove extending along the cooling channel is provided on the lower surface of the cooler; At least one reinforcing rib protruding toward the cooler is provided on the upper surface of the protective panel; and The reinforcing ribs are accommodated in the grooves of the cooler.

2. The battery pack according to claim 1, wherein: At least one engaging rib protruding toward the cooler is provided to the protective panel; The protective panel is bonded to the cooler via adhesive at the joint rib; The reinforcing ribs extend in a first direction on the upper surface of the protective panel. and The joining rib extends on the upper surface of the protective panel in a second direction intersecting the first direction.

3. The battery pack according to claim 2, wherein, On the upper surface of the protective panel, the width of the reinforcing rib perpendicular to the first direction is smaller than the width of the connecting rib perpendicular to the second direction.

4. The battery pack according to claim 2 or 3, wherein, On the upper surface of the protective panel, the protruding height dimension of the reinforcing rib is greater than that of the connecting rib.

5. The battery pack according to claim 2 or 3, wherein: The at least one connecting rib includes a first connecting rib, a second connecting rib, and a third connecting rib arranged along the first direction; and The at least one reinforcing rib includes: A plurality of first reinforcing ribs are positioned between the first connecting ribs and the second connecting ribs and are arranged along the second direction; as well as A plurality of second reinforcing ribs are positioned between the second and third joining ribs and arranged along the second direction.

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