Vehicle-width-direction end portion structure of battery pack

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The end structure for battery packs with deformable regions and fastening frames addresses the challenge of securing energy absorption during side collisions, ensuring efficient collision energy absorption and protection without enlarging the vehicle or reducing battery capacity.

WO2026126476A1PCT designated stage Publication Date: 2026-06-18MITSUBISHI MOTORS CORP

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Patent Information

Authority / Receiving Office: WO · WO
Patent Type: Applications
Current Assignee / Owner: MITSUBISHI MOTORS CORP
Filing Date: 2024-12-13
Publication Date: 2026-06-18

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Abstract

The present invention facilitates protection of a battery pack by securing the EA stroke of the battery pack and efficiently absorbing collision energy in a side collision.　A side wall 22 of a battery pack 10: comprises a first region 26 that protects a device inside the battery pack 10 when a load from the outside in the vehicle-width direction is applied, and a second region 28 that is provided on the outside of the first region 26 in the vehicle-width direction and that has a deformable region 36; and is provided with a fastening frame part 30 that protrudes to the outside in the vehicle-width direction from an end portion of the deformable region 36 in the vehicle-width direction and that is coupled to a vehicle skeleton member. The deformable region 36 is configured to include a space part 40 that allows the fastening frame part 30 to intrude thereinto when the load from the outside in the vehicle-width direction is applied to the fastening frame part 30.

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Description

End structure in the vehicle width direction of a battery pack 【0001】 The present invention relates to an end structure in the vehicle width direction of a battery pack. 【0002】 In an electric vehicle such as an electric vehicle or a hybrid vehicle using a motor as a drive source, a battery pack that supplies power to the motor includes a battery module composed of a plurality of battery cells, a control device for operating these battery modules, a cooling device for cooling the battery module, and a case of the battery pack that houses them. When the battery pack is disposed at the lower part of the vehicle body, the end portion in the vehicle width direction of the battery pack is supported by a vehicle skeleton member such as a side sill through a support structure made of sheet metal (see Patent Document 1). 【0003】 Japanese Patent No. 5434082 【0004】 By the way, in recent years, with the increase in the capacity of the battery pack, the dimensions of the battery pack in the vehicle width direction tend to increase. Therefore, since the space between both sides of the battery pack and the side sill is reduced, the dimensions of the support structure in the vehicle width direction have to be reduced, which is disadvantageous in securing an EA stroke (energy absorption stroke) for absorbing the collision energy during a side collision with the support structure. In order to secure the EA stroke, it is conceivable to increase the vehicle width size, but there is a disadvantage that the vehicle body becomes larger. Also, it is conceivable to reduce the vehicle width direction of the battery pack, but there is a disadvantage that it conflicts with the increase in the capacity of the battery pack. The present invention has been made in view of the above circumstances, and even when a large-capacity battery pack having a large dimension in the vehicle width direction compared to the dimension in the vehicle width direction of the vehicle body is mounted on the vehicle body, the EA stroke of the battery pack is secured and the collision energy during a side collision can be efficiently absorbed, and an end structure in the vehicle width direction of the battery pack advantageous for protecting the battery pack is provided. 【0005】To achieve the above objective, one embodiment of the present invention is a vehicle-width end structure at the bottom of a battery pack, having side walls provided at both ends in the vehicle-width direction of the bottom wall of the battery pack and extending in the vehicle-rear direction, wherein the side walls comprise a first region that protects the internal equipment of the battery pack when a load is applied from the outside in the vehicle-width direction, and a second region provided outside the first region in the vehicle-width direction and having a deformable region, and a fastening frame portion is provided that protrudes outward in the vehicle-width direction from the outer end of the deformable region and is connected to a vehicle frame member, wherein the deformable region is configured to include a space that allows the fastening frame portion to enter when a load is applied to the fastening frame portion from the outside in the vehicle-width direction. Furthermore, in one embodiment of the present invention, the fastening frame portion has a base portion connected to the outer end in the vehicle width direction of the deformable region and a tip portion located away from the base portion and connected to the vehicle frame member, and the base portion is provided with a groove that, by making the thickness of the base portion smaller than the thickness of the tip portion, displaces the tip portion above the base portion when a load from the outside in the vehicle width direction is applied to the tip portion, thereby inducing the tilting of the fastening frame portion. Furthermore, in one embodiment of the present invention, the groove is provided on the upper surface of the base portion. Furthermore, in one embodiment of the present invention, a first reinforcing portion is provided above the space portion, connecting the location of the first region where virtual extension lines extending inward in the vehicle width direction from the base portion intersect and the location located above the base portion at the outer end in the vehicle width direction of the deformable region, and is displaced gradually upward as it reaches the outside in the vehicle width direction. Furthermore, one embodiment of the present invention is characterized in that a second reinforcing portion is provided below the space portion, connecting the location of the first region where a virtual extension line extending inward from the base portion in the vehicle width direction intersects with the location of the non-deformable region located below the base portion at the outer end of the second region in the vehicle width direction, and which is displaced downward as it extends outward in the vehicle width direction.Furthermore, one embodiment of the present invention is characterized in that a reinforcing frame portion is provided which protrudes outward in the vehicle width direction below the fastening frame portion from a non-deformable region at the lower part of the outer end in the vehicle width direction of the second region and is connected to the tip of the fastening frame portion, and the reinforcing frame portion is provided which extends to guide the extension of the reinforcing frame portion in accordance with the tilting of the fastening frame portion. Furthermore, one embodiment of the present invention is characterized in that the first region, the second region and the fastening frame portion are integrally molded from an extruded material. 【0006】According to one embodiment of the present invention, the side wall of the battery pack comprises a first region that protects the internal components of the battery pack when a load is applied from the outside in the vehicle width direction, and a second region provided on the outside in the vehicle width direction of the first region and having a deformable region. A fastening frame portion is provided that protrudes outward in the vehicle width direction from the outer end of the deformable region and is connected to a vehicle frame member. The deformable region includes a space that allows the fastening frame portion to enter when a load is applied to the fastening frame portion from the outside in the vehicle width direction. Therefore, deformation of the fastening frame portion inward in the vehicle width direction due to the collision load applied during a side collision is permitted by the fastening frame portion entering the space of the second region. This deformation of the deformable region of the second region is advantageous in absorbing collision energy during a side collision, ensuring the EA stroke of the battery pack and efficiently absorbing collision energy during a side collision, which is advantageous in protecting the battery pack. Furthermore, if the fastening frame has a base and a tip located away from the base and connected to the vehicle's structural member, and if a groove is provided in the base to guide the tilting of the fastening frame, the downward displacement of the battery pack is promoted, thereby suppressing interference between the battery pack and other structures such as the floor panel located above it. Therefore, collision energy during a side collision can be efficiently absorbed. In addition, the inward deformation mode of the fastening frame in the vehicle width direction can be stabilized. Furthermore, since the groove makes it easier for the fastening frame to enter the space of the second region, the inward deformation mode of the fastening frame in the vehicle width direction can be stabilized. In addition, if the groove is provided on the upper surface of the base, the inward deformation mode of the fastening frame in the vehicle width direction can be further stabilized. Furthermore, by providing a first reinforcing section above the space, the base of the fastening frame section is received by the first reinforcing section via the second region due to the collision load, thereby changing the direction of movement of the base of the fastening frame section downward. Consequently, the direction of the collision load applied to the battery pack via the second and first regions is changed downward, which suppresses interference between the battery pack and other structures and allows for efficient absorption of collision energy during a side collision.Furthermore, if a second reinforcing section is provided below the space, the collision load is received by the base of the fastening frame section via the second region to the second reinforcing section, and the collision load is applied from the base of the fastening frame section to the second reinforcing section. Therefore, the direction of the collision load applied to the battery pack via the second and first regions is converted downwards, which suppresses interference of the battery pack with other structures, efficiently absorbs collision energy during side collisions, and is advantageous in protecting the battery pack. In addition, if a reinforcing frame section is provided that protrudes outward in the vehicle width direction below the fastening frame section from the non-deformable region and is connected to the tip of the fastening frame section, and the reinforcing frame section is provided with an extension section that guides the extension of the reinforcing frame section in accordance with the tilting of the fastening frame section, the extension of the reinforcing frame section is guided by the deformation of the extension section in response to the collision load, and the tilting of the fastening frame section can be performed without hindrance. Therefore, the deformation mode of the fastening frame section toward the inside in the vehicle width direction can be made more stable. Furthermore, integrally molding the first region, the second region, and the fastening frame portion using extruded material allows for easy manufacturing of the side walls and fastening frame portion, which is advantageous in reducing the manufacturing cost of the battery pack. 【0007】 This is a partial cross-sectional view of the end structure in the vehicle width direction of the battery pack according to the embodiment, broken in a plane perpendicular to the vehicle's longitudinal direction. This is a cross-sectional view of the end structure before a side collision. This is a cross-sectional view of the end structure showing the state in which deformation due to a side collision has begun. This is a cross-sectional view of the end structure showing the state in which deformation due to a side collision has almost finished. 【0008】 Embodiments of the present invention will now be described with reference to the drawings. The end structure of the battery pack in the vehicle width direction of this embodiment (hereinafter simply referred to as the end structure of the battery pack) is applied to a battery pack that is mounted on an electric vehicle that uses only a motor as a driving source, or a hybrid vehicle, or a plug-in hybrid vehicle that is capable of external charging or external power supply, and supplies power to the motor. 【0009】As shown in Figure 1, the battery pack 10 is located at the bottom of the vehicle body. In the following drawings, the symbol UP indicates the top of the vehicle, the symbol IN indicates the inside in the vehicle width direction, and the symbol OUT indicates the outside in the vehicle width direction. The vehicle body comprises a floor panel 12 extending in the vehicle's longitudinal and vehicle width directions, a seat cross member 14 extending in the vehicle width direction on the upper surface of the floor panel 12, and side sills 16 as vehicle frame members extending in the vehicle's longitudinal direction on both sides in the vehicle width direction. The side sills 16 are connected to both sides of the floor panel 12 in the vehicle width direction and to both ends in the longitudinal direction of the seat cross member 14. The side sills 16 are composed of a side sill outer 16A provided on the outside in the vehicle width direction, a side sill inner 16B provided on the inside in the vehicle width direction, and a side sill reinforcement 16C provided between the side sill outer 16A and the side sill inner 16B, and exhibit a closed cross section structure. 【0010】 The battery pack 10 is located below the floor panel 12. The battery pack 10 consists of a battery case 18, a battery pack 1002 consisting of multiple battery modules housed in the battery case 18, a control device (not shown) for controlling the battery pack 1002, a DC / DC converter (not shown), and a cooling device (not shown) for cooling the battery modules. The battery case 18 is made of steel and consists of a rectangular bottom wall 20 (battery tray) in plan view, side walls 22 provided at both ends of the bottom wall 20 in the vehicle width direction and extending in the vehicle front-rear direction, and a cover 24 provided on both side walls 22. The battery pack 1002, control device, DC / DC converter, and cooling device are housed in the space enclosed by the bottom wall 20, side walls 22, and cover 24. 【0011】As shown in Figures 1 and 2, the side wall 22 comprises a first region 26 and a second region 28, with a fastening frame portion 30 and a reinforcing frame portion 32 provided in the second region 28. These first region 26, second region 28, fastening frame portion 30, and reinforcing frame portion 32 extend along both ends of the bottom wall 20 in the vehicle width direction. The side wall 22, fastening frame portion 30, and reinforcing frame portion 32 are formed from extruded material rather than conventional sheet metal, and therefore the first region 26, second region 28, fastening frame portion 30, and reinforcing frame portion 32 are integrally molded. The first region 26 is provided on the inner side of the side wall 22 in the vehicle width direction. The first region 26 is a region that protects the battery case 18's components, such as the battery pack 1002, control device, DC / DC converter, and cooling device, when a load is applied from the outside in the vehicle width direction. Therefore, the first region 26 is formed as a non-deformable region with rigidity that is resistant to deformation when a load is applied from the outside in the vehicle width direction. In this embodiment, the first region 26 is formed of a steel portion with a predetermined thickness in the vehicle width direction and a vertically elongated rectangular cross-section that extends in the vertical direction, and two (or more) vertically elongated spaces are formed inside for weight reduction. 【0012】 As shown in Figure 2, the second region 28 is located outside the first region 26 in the vehicle width direction. The second region 28 comprises a non-deformable region 34 having rigidity that makes it difficult to deform when a load is applied from the outside in the vehicle width direction, and a deformable region 36 having rigidity that allows it to absorb the load by deforming when a load is applied from the outside in the vehicle width direction. The non-deformable region 34 is an upper non-deformable region 34A and a lower non-deformable region 34B, located at the top and bottom of the second region 28. The deformable region 36 is located between the upper non-deformable region 34A and the lower non-deformable region 34B. 【0013】The upper non-deformable region 34A is composed of a first horizontal plate 3402 and a second horizontal plate 3404 projecting from the upper outer end in the vehicle width direction of the first region 26, a vertical plate 3406 connecting the outer ends in the vehicle width direction of the first horizontal plate 3402 and the second horizontal plate 3404, and a space 3410 formed by the first horizontal plate 3402, the second horizontal plate 3404, the vertical plate 3406 and the upper end in the vehicle width direction of the first region 26. The lower non-deformable region 34B is composed of a third horizontal plate 3408 projecting from the lower outer end in the vehicle width direction of the first region 26. The vertical plate 3406 constituting the upper non-deformable region 34A extends downward and is connected to the outer end in the vehicle width direction of the third horizontal plate 3408. Therefore, since the deformable region 36 is provided between the upper non-deformable region 34A and the lower non-deformable region 34B, the vertical plate 3406 passes through the deformable region 36, and the portion 3406A of the vertical plate 3406 located in the deformable region 36 constitutes the deformable region 36. 【0014】As shown in Figure 1, the fastening frame portion 30 protrudes outward in the vehicle width direction from the vertical plate 3406, which is the outer end of the deformable region 36 in the vehicle width direction, and is connected by bolts 38 to the side sill 16 (side sill inner 16B) which constitutes the vehicle frame member. As shown in Figure 2, the deformable region 36 is composed of a portion 3406A of the vertical plate 3406 located between the upper non-deformable region 34A and the lower non-deformable region 34B, and a space portion 40 provided on the inside of the portion 3406A of the vertical plate 3406 in the vehicle width direction, which allows the portion 3406A of the vertical plate 3406 and the fastening frame portion 30 to enter when a load from the outside in the vehicle width direction is applied to the fastening frame portion 30. The fastening frame portion 30 has a base portion 3002 that is connected to the portion 3406A of the vertical plate 3406, which is the outer end of the deformable region 36 in the vehicle width direction, and a tip portion 3004 that is located away from the base portion 3002 and is connected to the vehicle frame member. The base portion 3002 is provided with a groove 3006 that, by making the thickness of the base portion 3002 smaller than the thickness of the tip portion 3004, displaces the tip portion 3004 above the base portion 3002 when a load from the outside in the vehicle width direction is applied to the tip portion 3004, thereby inducing the tilting of the fastening frame portion 30. The groove 3006 is provided on the upper surface of the base portion 3002. Furthermore, in order that the tip portion 3004 of the fastening frame portion 30 falls within the height range of the second region 28 when the fastening frame portion 30 tilts, the deformable region 36 on which the fastening frame portion 30 protrudes is provided at a location displaced below the vertical center of the second region 28. 【0015】As shown in Figure 2, above the space 40, a first reinforcing portion 42 is provided, connecting the location of the first region 26 where virtual extension lines extending inward in the vehicle width direction from the base 3002 of the fastening frame portion 30 intersect, and the location of the vertical plate 3406 located above the base 3002 of the fastening frame portion 30, and gradually displacing upward as it approaches the outside in the vehicle width direction. Below the space 40, a second reinforcing portion 44 is provided, connecting the location of the first region 26 where virtual extension lines extending inward in the vehicle width direction from the base 3002 of the fastening frame portion 30 intersect, and the location of the vertical plate 3406 located below the base 3002 of the fastening frame portion 30, and gradually displacing downward as it approaches the outside in the vehicle width direction. Therefore, the space 40 is formed between the vertical plate 3406, the first reinforcing portion 42, and the second reinforcing portion 44. The first reinforcing section 42 and the second reinforcing section 44 are formed with a rigidity that makes them resistant to deformation when a load is applied from the outside in the vehicle width direction. 【0016】 As shown in Figure 2, the reinforcing frame portion 32 protrudes outward in the vehicle width direction from the lower non-deformable region 34B at the outer end of the second region 28 in the vehicle width direction, below the fastening frame portion 30, and is connected to the tip portion 3004 of the fastening frame portion 30, thereby reinforcing the fastening frame portion 30. The reinforcing frame portion 32 is configured to include an inclined portion 3202 that displaces upward as it reaches the outer side in the vehicle width direction. The reinforcing frame portion 32 is equipped with an extension portion 3204 that guides the extension of the reinforcing frame portion 32 in accordance with the tilting of the fastening frame portion 30. The extension portion 3204 is formed by a bent portion provided on the base portion 3002 of the fastening frame portion 30 near the lower non-deformable region 34B. Various conventionally known structures can be adopted for the extension portion 3204, such as forming the extension portion 3204 with a thin-walled portion. 【0017】Next, with reference to Figures 2-4, the effects of the end structure of the battery pack 10 in this embodiment during a side collision will be explained. In Figures 2-4, the side sill 16 is simplified and shown by a dashed line. Figure 2 shows the state before a side collision. As shown in Figure 3, when a side collision occurs and a collision load F from the outside in the vehicle width direction is input to the front part 3004 of the fastening frame part 30 via the side sill 16, the fastening frame part 30 tilts, with the front part 3004 displaced above the base part 3002, using the groove 3006 on the upper surface of the base part 3002 as the pivot point. The collision energy is absorbed by the fastening frame part 30 due to this deformation of the fastening frame part 30. Also, as the fastening frame part 30 tilts, displacing the front part 3004 fastened to the side sill 16 above the base part 3002, the battery pack 10 is displaced so that the side on which the collision load F was input moves downward away from the side sill 16. As the tip 3004 of the fastening frame portion 30 is displaced upward, a force is applied from the tip 3004 of the fastening frame portion 30 to the reinforcing frame portion 32 in a direction that causes the reinforcing frame portion 32 to extend. This causes the extension portion 3204 to deform and extend, thereby inducing elongation of the reinforcing frame portion 32. Consequently, the fastening frame portion 30 can tilt without hindrance, and the impact energy is absorbed by the reinforcing frame portion 32 as the extension portion 3204 extends. 【0018】 As shown in Figure 4, the collision load F causes the fastening frame portion 30 to tilt, and the collision load F from the outside in the vehicle width direction applied to the fastening frame portion 30 is added to the deformable region 36 of the second region 28. As a result, portion 3406A of the vertical plate 3406 that constitutes the deformable region 36 of the second region 28 deforms inward in the vehicle width direction, and since the inward deformation of portion 3406A of the vertical plate 3406 in the vehicle width direction is permitted by the space portion 40, portion 3406A of the vertical plate 3406 and the base portion 3002 of the fastening frame portion 30 penetrate into the space portion 40. In this way, the inward deformation of portion 3406A of the vertical plate 3406 in the vehicle width direction is permitted by the space portion 40, and the collision energy is absorbed by the deformation of portion 3406A of the vertical plate 3406. 【0019】Furthermore, the base 3002 of the fastening frame portion 30 that has entered the space 40 is received by the first reinforcing portion 42 and the second reinforcing portion 44 via the second region 28. As the base 3002 of the fastening frame portion 30 is received by the first reinforcing portion 42 via the second region 28 (a portion 3406A of the vertical plate 3406 that constitutes the deformable region 36), the direction of movement of the base 3002 of the fastening frame portion 30 is changed downward, and therefore the direction of the collision load F applied to the battery pack 10 via the second region 28 and the first region 26 is changed downward. Furthermore, the base 3002 of the fastening frame portion 30 is received by the second reinforcing portion 44 via the second region 28 (a portion 3406A of the vertical plate 3406 that constitutes the deformable region 36), so that the collision load F is applied from the base 3002 of the fastening frame portion 30 to the second reinforcing portion 44, and therefore the direction of the collision load F applied to the battery pack 10 via the second region 28 and the first region 26 is converted downward. By converting the direction of the collision load F applied to the battery pack 10 downward in this way, the downward displacement of the battery pack 10 is promoted. 【0020】 Therefore, the collision energy due to the collision load F is absorbed by the bending of the fastening frame portion 30, the extension of the reinforcing frame portion 32, and the deformation of the deformable region 36 of the second region 28, while the first region 26 does not deform due to the collision energy, thus protecting the equipment inside the battery pack 10 from the collision energy due to the collision load F. If the magnitude of the collision load F applied to the side sill 16 from the outside in the vehicle width direction is small enough that the fastening frame portion 30 does not bend, the reinforcing frame portion 32 will receive the collision load F together with the fastening frame portion 30, so the collision load F will be transmitted from the fastening frame portion 30 and the reinforcing frame portion 32 to the first region 26 via the second region 28, and then distributed and transmitted throughout the entire battery pack 10 via the side wall 22. 【0021】According to this embodiment, the side wall 22 of the battery pack 10 includes a first region 26 that protects the internal components of the battery pack 10 when a load is applied from the outside in the vehicle width direction, and a second region 28 that is located outside the first region 26 in the vehicle width direction and has a deformable region 36. A fastening frame portion 30 is provided that protrudes outward in the vehicle width direction from the outer end of the deformable region 36 and is connected to a vehicle frame member. The deformable region 36 includes a space 40 that allows the fastening frame portion 30 to enter when a load is applied to the fastening frame portion 30 from the outside in the vehicle width direction. Therefore, deformation of the fastening frame portion 30 inward in the vehicle width direction due to the collision load F input during a side collision is allowed by the fastening frame portion 30 entering the space 40 of the second region 28, which is advantageous in absorbing collision energy during a side collision by the deformation of the deformable region 36 of the second region 28. Therefore, even when a large-capacity battery pack 10, which has a larger width dimension compared to the width dimension of the vehicle body, is mounted on the vehicle body, the EA stroke of the battery pack 10 can be secured, allowing for efficient absorption of collision energy during a side collision, which is advantageous in protecting the battery pack 10. 【0022】Furthermore, in this embodiment, the fastening frame portion 30 has a base portion 3002 connected to the outer end in the vehicle width direction of the deformable region 36, and a tip portion 3004 located away from the base portion 3002 and connected to the vehicle frame member. The base portion 3002 is provided with a groove 3006 that, by making the thickness of the base portion 3002 smaller than the thickness of the tip portion 3004, displaces the tip portion 3004 upward relative to the base portion 3002 when a load from the outside in the vehicle width direction is applied to the tip portion 3004, thereby inducing the tilting of the fastening frame portion 30. As a result, downward displacement of the battery pack 10 is promoted, and interference between the battery pack 10 and other structures such as the floor panel 12 located above the battery pack 10 is suppressed. Therefore, since the deformation of the fastening frame portion 30 and the deformable region 36 of the second region 28 is not hindered by interference between the battery pack 10 and other structures, collision energy during a side collision can be efficiently absorbed, which is advantageous in protecting the battery pack 10. Furthermore, the collision load F input from the side sill 16 during a side collision stabilizes the direction in which the fastening frame portion 30 tilts, thereby stabilizing the inward deformation mode of the fastening frame portion 30 in the vehicle width direction. Therefore, collision energy can be efficiently absorbed by the fastening frame portion 30 and the deformable region 36 of the second region 28, which is advantageous in protecting the battery pack 10. In addition, since the groove 3006 is structurally weak and prone to bending and crushing, the area of the groove 3006 can easily enter the space 40 of the second region 28, thereby stabilizing the inward deformation mode of the fastening frame portion 30 in the vehicle width direction. Therefore, collision energy can be efficiently absorbed by the fastening frame portion 30 and the deformable region 36 of the second region 28, which is advantageous in protecting the battery pack 10. 【0023】Furthermore, in this embodiment, since the groove 3006 is provided on the upper surface of the base 3002, it is advantageous in stabilizing the direction in which the fastening frame portion 30 tilts due to the collision load F input from the side sill 16 during a side collision, and the deformation mode of the fastening frame portion 30 toward the inside in the vehicle width direction can be further stabilized. Therefore, collision energy can be efficiently absorbed by the fastening frame portion 30 and the deformable region 36 of the second region 28, which is advantageous in protecting the battery pack 10. 【0024】 Furthermore, in this embodiment, a first reinforcing portion 42 is provided above the space portion 40, connecting the location of the first region 26 where a virtual extension line extending inward from the base portion 3002 in the vehicle width direction intersects with the location of the deformable region 36 at the outer end in the vehicle width direction, which is located above the base portion 3002, and which gradually displaces upward as it reaches the outer side in the vehicle width direction. As a result, when a side collision occurs, the collision load F input from the side sill 16 causes the base portion 3002 of the fastening frame portion 30 to be received by the first reinforcing portion 42 via the deformable region 36 of the second region 28, thereby changing the direction of movement of the base portion 3002 of the fastening frame portion 30 downward. Consequently, the direction of the collision load F applied to the battery pack 10 via the second region 28 and the first region 26 is changed downward. This promotes the downward displacement of the battery pack 10, which suppresses interference between the battery pack 10 and other structures such as the floor panel 12 located above it. This allows for efficient absorption of collision energy during a side collision, which is advantageous in protecting the battery pack 10. 【0025】Furthermore, in this embodiment, below the space 40, a second reinforcing portion 44 is provided that connects the location of the first region 26 where virtual extension lines extending inward in the vehicle width direction from the base portion 3002 intersect with the location of the non-deformable region 34 located below the base portion 3002 at the outer end of the second region 28 in the vehicle width direction, and which gradually displaces downward as it reaches the outer side in the vehicle width direction. Therefore, in the event of a side collision, the collision load F input from the side sill 16 causes the base portion 3002 of the fastening frame portion 30 to be received by the second reinforcing portion 44 via the deformable region 36 of the second region 28, thereby transferring the collision load F from the base portion 3002 of the fastening frame portion 30 to the second reinforcing portion 44, and consequently, the direction of the collision load F applied to the battery pack 10 via the second region 28 and the first region 26 is converted downward. This promotes the downward displacement of the battery pack 10, which suppresses interference between the battery pack 10 and other structures such as the floor panel 12 located above it. This allows for efficient absorption of collision energy during a side collision, which is advantageous in protecting the battery pack 10. 【0026】 Furthermore, in this embodiment, a reinforcing frame portion 32 is provided, which protrudes outward in the vehicle width direction below the fastening frame portion 30 from the non-deformable region 34 at the lower part of the outer end of the second region 28 in the vehicle width direction and is connected to the tip portion 3004 of the fastening frame portion 30. The reinforcing frame portion 32 is provided with an extension portion 3204 that guides the extension of the reinforcing frame portion 32 in accordance with the tilting of the fastening frame portion 30. Therefore, when a collision load F is input from the side sill 16 during a side collision, the extension portion 3204 deforms to extend, thereby guiding the extension of the reinforcing frame portion 32, and allowing the fastening frame portion 30 to tilt without hindrance. Consequently, the deformation mode of the fastening frame portion 30 toward the inside in the vehicle width direction can be further stabilized, and collision energy can be efficiently absorbed by the fastening frame portion 30 and the deformable region 36 of the second region 28. In addition, collision energy is absorbed by the reinforcing frame portion 32 when the extension portion 3204 extends, which is more advantageous in protecting the battery pack 10. 【0027】Furthermore, in this embodiment, since the first region 26, the second region 28, the fastening frame portion 30, and the reinforcing frame portion 32 are integrally molded from extruded material, the side wall 22, the fastening frame portion 30, and the reinforcing frame portion 32 can be easily manufactured, which is advantageous in reducing the manufacturing cost of the battery pack 10. 【0028】 10 Battery pack 1002 Battery assembly 12 Floor panel 14 Seat cross member 16 Side sill 16A Side sill outer 16B Side sill inner 16C Side sill reinforcement 18 Battery case 20 Bottom wall 22 Side wall 24 Cover 26 First area 28 Second area 30 Fastening frame section 3002 Base section 3004 Tip section 3006 Groove 32 Reinforcement frame section 3202 Inclined section 3204 Extension section 34 Non-deformable area 34A Upper non-deformable area 34B Lower non-deformable area 3402 First horizontal plate 3404 Second horizontal plate 3406 Vertical plate 3406A Section 3408 Third horizontal plate 3410 Space 36 Deformable area 38 Bolt 40 Space 42 First reinforcement section 44 Second reinforcement section

Claims

1. A vehicle-width end structure for the lower part of a battery pack, comprising: side walls provided at both ends of the bottom wall of the battery pack in the vehicle-width direction and extending in the vehicle-rear direction, the side walls comprising: a first region that protects the internal equipment of the battery pack when a load is applied from the outside in the vehicle-width direction; and a second region provided outside the first region in the vehicle-width direction and having a deformable region, a fastening frame portion provided that protrudes outward in the vehicle-width direction from the outer end of the deformable region and is connected to a vehicle frame member, and the deformable region is configured to include a space that allows the fastening frame portion to enter when a load is applied to the fastening frame portion from the outside in the vehicle-width direction.

2. The fastening frame portion has a base portion connected to the outer end in the vehicle width direction of the deformable region, and a tip portion located away from the base portion and connected to the vehicle frame member, and the base portion is provided with a groove that, by making the thickness of the base portion smaller than the thickness of the tip portion, displaces the tip portion upward relative to the base portion when a load from the outside in the vehicle width direction is applied to the tip portion, thereby inducing the tilting of the fastening frame portion, as described in claim 1.

3. The end structure in the vehicle width direction of the battery pack according to claim 2, characterized in that the groove is provided on the upper surface of the base.

4. The end structure of the battery pack in the vehicle width direction according to claim 1, characterized in that a first reinforcing portion is provided above the space portion, connecting the location of the first region where a virtual extension line extending inward in the vehicle width direction from the base portion intersects with the location of the deformable region at the outer end in the vehicle width direction above the base portion, and the reinforcing portion is provided which is gradually displaced upward as it reaches the outer end in the vehicle width direction.

5. The end structure of the battery pack in the vehicle width direction according to claim 1, characterized in that a second reinforcing portion is provided below the space, connecting the location of the first region where a virtual extension line extending inward from the base in the vehicle width direction intersects with the location of the non-deformable region located below the base at the outer end of the second region in the vehicle width direction, and which is displaced downward as it extends outward in the vehicle width direction.

6. The end structure for a battery pack in the vehicle width direction according to claim 2, characterized in that it comprises a reinforcing frame portion that protrudes outward in the vehicle width direction below the fastening frame portion from an immovable region at the lower part of the outer end in the vehicle width direction of the second region and is connected to the tip of the fastening frame portion, the reinforcing frame portion comprises an extension portion that guides the extension of the reinforcing frame portion in accordance with the tilting of the fastening frame portion.

7. The end structure in the vehicle width direction of the battery pack according to claim 1, characterized in that the first region, the second region, and the fastening frame portion are integrally molded from an extruded material.