Battery pack protection structure

Abstract

The battery pack protective structure includes a cross member (20) having a bent portion (2A) formed along a corner portion (17) of a case (12) of a battery pack (10) and an inner portion (2B) extending inward in the vehicle width direction from the bent portion (2A) along the bottom surface (15), and extending along the vehicle width direction; a first reinforcement (40) superimposed on the cross member (20) along the bent portion (2A) on at least one of the upper and lower sides of the cross member (20); a first portion (51) overlapping at least a portion of the portion of the first reinforcement (40) along the bent portion (2A) in a planar view; and a second portion (52) extending inward in the vehicle width direction from the first portion (51) and overlapping at least a portion of the inner portion (2B) in a planar view, and superimposed on the cross member (20) on at least one of the upper and lower sides of the cross member (20).

Description

[Technical Field]

[0001] The present invention relates to a battery pack protection structure for protecting a battery pack mounted in a vehicle. [Background technology]

[0002] A vehicle is provided with a body structure (framework members) such as a cross member extending along the vehicle width direction and a side member extending along the vehicle longitudinal direction. Such a body structure is also applied to electric vehicles (electric vehicles, hybrid electric vehicles, etc.) equipped with a battery pack as a power source for driving the vehicle. The battery pack contains a secondary battery module in an internal space formed by attaching a cover (lid) to a case (also called a casing or tray). For example, Patent Document 1 proposes a structure in which a cross member extends along the bottom and side of a tray for a vehicle equipped with a battery pack. In this structure, the cross member is attached along the corner formed by the bottom of the case and the side of the case located outside in the vehicle width direction. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2020-155341 Summary of the Invention [Problem to be solved by the invention]

[0004] However, because the corners of the case of an on-board battery pack are prone to deformation due to external forces acting along the vehicle width, a cross member bent along the corners alone may not be able to sufficiently suppress deformation. For example, when a vehicle is hit in a side collision, an impact is applied from the outside to the inside of the vehicle width, causing deformation of the corners of the case and possibly also causing deformation of the bottom surface of the case extending in the vehicle width direction. Since the corners and bottom surface of the case, which should be suppressed, cannot be suppressed, the battery pack may not be sufficiently protected. Therefore, there is room for improvement in terms of ensuring the protection of the battery pack.

[0005] The battery pack protective structure of the present invention was invented in light of these problems, and one of its objectives is to ensure the protection of the battery pack. However, in addition to this objective, another objective of the present invention is to achieve the effects derived from the configurations shown in the "Description of Embodiments" below, which are not obtainable with conventional technology. [Means for solving the problem]

[0006] The disclosed battery pack protective structure can be realized as the following disclosed embodiments (application examples), which solve at least part of the above-mentioned problems. Each of the embodiments from embodiment 2 onwards is an embodiment that can be selected as an additional option, and each of the embodiments from embodiment 2 onwards is an embodiment that can be omitted. None of the embodiments from embodiment 2 onwards discloses an embodiment or configuration that is essential to the present invention.

[0007] Aspect 1. The disclosed battery pack protective structure includes a cross member, a first reinforcement, and a second reinforcement. The cross member has a bent portion that follows a corner formed by the bottom surface of a battery pack case mounted on a vehicle and a side surface located at a vehicle width direction end of the case, and an inner portion that extends from the bent portion along the bottom surface toward the vehicle width direction inward, and extends along the vehicle width direction. The first reinforcement is overlapped with the cross member along the bent portion on at least one of the upper and lower sides of the cross member. The second reinforcement has a first portion that overlaps at least a portion of the portion of the first reinforcement that follows the bent portion in a plan view, and a second portion that extends from the first portion toward the vehicle width direction inward and overlaps at least a portion of the inner portion in a plan view, and is overlapped with the cross member on at least one of the upper and lower sides of the cross member.

[0008] Aspect 2. In the above aspect 1, it is preferable that the first portion has a side portion extending along the side surface. Aspect 3. In the above aspect 1 or 2, it is preferable that the first reinforcement and the second reinforcement are arranged in the order of the first reinforcement and the second reinforcement from the cross member side.

[0009] Aspect 4. In any one of the above aspects 1 to 3, it is preferable that the first reinforcement has an upper first reinforcement arranged above the cross member and a lower first reinforcement arranged below the cross member, and that the second reinforcement has an upper second reinforcement arranged above the cross member and a lower second reinforcement arranged below the cross member.

[0010] Aspect 5. In any one of Aspects 1 to 4 above, the second portion preferably includes a portion that overlaps with the battery module housed in the case in a plan view. Aspect 6. In any one of Aspects 1 to 5 above, it is preferable that the battery pack protective structure includes a side member that extends in the fore-and-aft direction of the vehicle along the side surface and is attached across a plurality of the cross members that are arranged side by side at intervals in the fore-and-aft direction.

[0011] Aspect 7. In the above aspect 6, the battery pack protective structure preferably includes a third reinforcement member superimposed along the side member. Aspect 8. In any one of the above aspects 1 to 7, the cross member has a pair of flange portions extending to the front and rear of the vehicle, respectively, a bottom portion extending between the pair of flange portions and positioned lower than the pair of flange portions, and a wall portion connecting each of the pair of flange portions and the bottom portion vertically, and it is preferable that the first reinforcement is formed along the bottom portion and the wall portion.

[0012] Aspect 9. In any one of Aspects 1 to 8 above, it is preferable that the first reinforcement has ribs extending along the vehicle width direction and projecting downward on each of the front and rear sides of the vehicle. Aspect 10. In any one of Aspects 1 to 9 above, it is preferable that the cross member, the first reinforcement, and the second reinforcement are provided only on the outside of the case. [Effects of the Invention]

[0013] According to the disclosed battery pack protective structure, the protection of the battery pack can be ensured. [Brief explanation of the drawings]

[0014] [Figure 1] 1 is a perspective view showing a battery pack and its surrounding configuration of a battery pack protective structure according to an embodiment; [Figure 2] 2 is an exploded perspective view showing the case of the battery pack of FIG. 1 and the peripheral members thereof. FIG. [Figure 3]2 is an exploded perspective view showing the main part of the structure for reinforcing the battery pack of FIG. 1. FIG. [Figure 4] 2 is a longitudinal cross-sectional view showing a cross section of a main part of the battery pack protective structure of FIG. 1. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0015] An embodiment of a battery pack protective structure will be described with reference to the drawings. The embodiment described below is merely an example, and is not intended to exclude various modifications or applications of techniques not explicitly described in the embodiment. The configurations of the embodiment can be modified in various ways without departing from the spirit of the embodiment. Furthermore, they can be selected or combined as needed.

[0016] In the following description, the forward direction of the vehicle is defined as the front, and the backward direction as the rear, and left and right are defined based on the front. Since the left and right direction is the width direction of the vehicle, in this embodiment the left and right direction is referred to as the "vehicle width direction" of the vehicle. Furthermore, the up and down direction is defined with the direction of gravity as the downward direction and the opposite direction as the upward direction. A view from above or below (i.e., a view along the up and down direction) is called a plan view, and a view from the right or left (i.e., a view along the vehicle width direction) is called a side view. Note that the up and down direction does not have to completely coincide with the vertical direction and may be slightly inclined relative to the vertical direction. Similarly, the front and back direction of the vehicle (hereinafter simply referred to as the "front and back direction") and the vehicle width direction do not have to completely coincide with the horizontal direction.

[0017] Vehicle structures are often formed with near bilateral symmetry (mirror symmetry about a plane including the yaw axis and roll axis passing through the center of gravity of the vehicle), but a completely symmetrical shape is not required. Furthermore, the type of vehicle to which the structure according to the embodiment is applied is not particularly limited as long as it is equipped with at least a battery pack, and can be applied to, for example, electric vehicles (EVs, electric vehicles), hybrid vehicles (HEVs, hybrid electric vehicles), plug-in hybrid vehicles (PHEVs, plug-in hybrid electric vehicles), etc. A plug-in hybrid vehicle is a hybrid vehicle whose battery can be externally charged or externally powered from the battery. A plug-in hybrid vehicle is provided with a charging port (inlet) for inserting a charging cable that supplies power from an external charging facility, and a power outlet (outlet) for external power supply.

[0018] I. ONE EMBODIMENT In the following embodiment, a battery pack protection structure that protects a battery pack mounted in a vehicle will be described. [1. Configuration] Fig. 1 is a perspective view showing an overview of a battery pack protective structure according to an embodiment, showing a battery pack 10 and the vehicle body structure provided around it from diagonally above on the front left side of the vehicle. Fig. 2 is an exploded perspective view showing the case 12 of the battery pack 10 in Fig. 1 and the various components around it. Fig. 3 is an exploded perspective view showing the main parts of the structure that reinforces the battery pack 10. Fig. 4 is a longitudinal cross-sectional view showing the main parts of the battery pack protective structure, a cross-section along the vehicle width direction and the up-down direction as viewed from the front.

[0019] <Basic configuration of battery pack protection structure> As shown in FIGS. 1 and 2, frame members such as a cross member 20 and side members 30 are provided around the battery pack 10. The battery pack 10 is a device for driving a vehicle that houses power storage devices such as battery modules 11 (shown by dashed lines in FIG. 1) inside a case 12. The battery pack 10 illustrated in FIG. 1 illustrates a layout in which four battery modules 11 are arranged side by side in the vehicle width direction.

[0020] The battery module 11 is a secondary battery that can not only supply power but also be charged. The battery module 11 has a larger capacity than an in-vehicle battery such as a 12V battery or a 24V battery. The battery module 11 is a relatively heavy device among the various devices and components housed in the battery pack 10. Case 12 is provided with opening 14 (see FIG. 2) that is closed by cover 13 (see FIG. 1). Battery module 11 and other power storage devices are disposed inside case 12 through opening 14 before cover 13 is attached to case 12.

[0021] As shown in FIG. 2, the case 12 has a bottom surface 15 located below the case 12 and side surfaces 16 located at the side ends of the case 12 in the vehicle width direction. The bottom surface 15 is a planar portion extending horizontally. The side surfaces 16 are planar portions provided on the left and right sides and extending upward from the outer end of the bottom surface 15 in the vehicle width direction. The bottom surface 15 and side surfaces 16 form corners 17 extending in the front-to-rear direction on the lower side and on the vehicle width direction end side of the case 12. In other words, the corners 17 are linear portions corresponding to the fold lines formed by bending one of the bottom surface 15 and the side surfaces 16 toward the other. The cross member 20 having a portion along the corners 17 formed by the bottom surface 15 and the side surfaces 16 in this manner will now be described.

[0022] The cross member 20 is a member that extends in the vehicle width direction and forms part of the vehicle body structure. In one embodiment, the cross member 20 is not provided inside the case 12, but only on the outside of the case 12. The cross member 20 is formed along the outer shape of the case 12. Specifically, the cross member 20 has left and right bent portions 2A formed along the left and right corners 17 of the case 12, and inner portions 2B extending inward in the vehicle width direction from each bent portion 2A. The cross member 20 of this embodiment has a vertical cross-sectional shape along the vehicle width direction that is convex downward due to the two bent portions 2A and the inner portion 2B located between them. Because the left and right bent portions 2A have symmetrical shapes, only one of the bent portions 2A will be described.

[0023] Bent portion 2A is located on the outer side or below corner 17 of case 12 in the vehicle width direction, and is a portion bent along corner 17. Like corner 17 of case 12, bent portion 2A is a linear portion (or a curved surface with a small area) extending in the front-to-rear direction. This bent portion 2A not only serves as part of the vehicle body structure, but also as a protective structure for corner portion 17. For example, when an external force acting inward in the vehicle width direction is applied, bent portion 2A functions as a protective structure that prevents side surface 16 forming corner portion 17 from deforming so as to collapse inward in the vehicle width direction.

[0024] The inner portion 2B is located below the bottom surface 15 of the case 12 and is formed along the bottom surface 15. The inner portion 2B, which extends below the case 12 in the horizontal direction, can be said to be a portion of the cross member 20 that supports the case 12 from below, and can also be said to be a portion that provides a protective structure that protects the bottom surface 15 from below. As shown in FIG. 3, the cross member 20 having the inner portion 2B provided on the inner side in the vehicle width direction relative to the bent portion 2A has a hat-shaped upper and lower cross section along the front-rear direction (a so-called hat cross section).

[0025] Specifically, the cross member 20 has a pair of flanges 2C extending to the front and rear, respectively, a bottom 2D extending between the pair of flanges 2C and positioned lower than the pair of flanges 2C, and a wall 2E connecting each of the pair of flanges 2C to the bottom 2D. In other words, a recess is defined between the flanges 2C by the bottom 2D and the two wall 2E. Because each wall 2E extends upward from the bottom 2D, it can be said that it is a portion that increases the rigidity of the cross member 20 and may also be called a rib.

[0026] 1 and 2 show an example of a structure provided with three (plural) cross members 20. The three cross members 20 are arranged side by side at intervals in the fore-and-aft direction. When it is necessary to distinguish between the three cross members 20, they will be referred to as a first cross member 21, a second cross member 22, and a third cross member 23 in order from front to rear.

[0027] In addition, the vehicle to which the battery pack protective structure of this embodiment is applied is provided with pillars (not shown) that serve as supports for the vehicle roof (not shown). The pillars are not provided near the first cross member 21 or the second cross member 22, but are provided near the third cross member 23. When a large external force is applied to the third cross member 23 from the outside in the vehicle width direction, such as during a side collision of the vehicle, part of the external force is distributed to the pillar, and the remainder of the external force (the part other than the part distributed to the pillar) is received by the third cross member 23.

[0028] On the other hand, when a large external force is applied to the first cross member 21 or the second cross member 22 from the outside in the vehicle width direction, such as during a side collision of the vehicle, almost all of the external force is received by the first cross member 21 or the second cross member 22 without being dispersed to the pillars. Therefore, it can be said that the first cross member 21 and the second cross member 22 are positioned in areas that require reinforcement more than the third cross member 23.

[0029] The side members 30 are components that extend in the front-to-rear direction on the left and right sides (outside in the vehicle width direction) of the battery pack 10 and form part of the vehicle body structure. The side members 30 are attached across the three cross members 20. The side members 30 illustrated in the embodiment are not provided inside the case 12 but only on the outside of the case 12 .

[0030] 2 and 4 is composed of two members, an upper side member 3U and a lower side member 3L. Specifically, the hollow side member 30 is formed by joining together the upper side member 3U, which has an upwardly convex shape in a vertical cross section along the vehicle width direction, and the lower side member 3L, which has a downwardly convex shape. 4 is disposed between the side surface 16 of the case 12 and the cross member 20. Because the side member 30 is interposed between the case 12 and the cross member 20 in this manner, the second angle θ2 formed by the bent portion 2A of the cross member 20 is set to be larger than the first angle θ1 formed by the corner portion 17 of the case 12 when viewed from the front-rear direction.

[0031] The battery pack 10, which is surrounded by the cross members 20 and side members 30, is disposed below a floor panel (not shown). When the battery pack 10 is disposed under the floor of the vehicle (i.e., outside the passenger compartment) in this manner, simply providing the cross members 20 and side members 30 around the battery pack 10 may not be enough to protect the battery pack 10.

[0032] For example, when a large external force is applied from the outside to the inside in the vehicle width direction, such as during a side collision of the vehicle, the bending portion 2A of the cross member 20 may be unable to maintain its shape and may bend and collapse inward in the vehicle width direction (hereinafter referred to as ``member collapse deformation''), or the inner portion 2B of the cross member 20 may be unable to maintain its shape and may be distorted into an uneven shape when viewed from the front-to-rear direction (hereinafter referred to as ``member distortion deformation'').

[0033] The member collapse deformation may cause deformation that causes the side surface 16 forming the corner portion 17 to collapse inward in the vehicle width direction (hereinafter referred to as "case collapse deformation"). In addition, the member distortion deformation may cause deformation that distorts the bottom surface 15 (hereinafter referred to as "case distortion deformation"). As described above, when the case 12 is deformed due to the case collapse deformation caused by the collapse deformation of the members or the case distortion deformation caused by the distortion deformation of the members, the protectiveness of the battery pack 10 is reduced. Therefore, the battery pack protective structure of this embodiment is provided with a reinforcing member that suppresses the collapse deformation of the members and the distortion deformation of the members.

[0034] <Detailed configuration of battery pack protection structure> In the battery pack protective structure of this embodiment, as shown in FIGS. 3 and 4, two types of reinforcements 40, 50 are provided as reinforcing members for suppressing deformation. The two types of reinforcements 40, 50 are members that reinforce the cross member 20 and are overlapped with at least a portion of the cross member 20. Of the two types of reinforcements 40, 50, one is a first reinforcement 40 that is mainly responsible for reinforcing the bent portion 2A, and the other is a second reinforcement 50 that is mainly responsible for reinforcing the inner portion 2B.

[0035] These two types of reinforcements 40, 50 are both arranged on at least one of the upper and lower sides of the cross member 20. In other words, the first reinforcement 40 and the second reinforcement 50 are arranged side by side on at least the same vertical side of the cross member 20. In this way, the two types of reinforcements 40, 50 that reinforce the cross member 20 from at least one side are provided only on the outside of the case 12, just like the cross member 20 that they are intended to reinforce.

[0036] The two types of reinforcements 40, 50 exemplified in this embodiment are each disposed on both the upper and lower sides of the cross member 20. Specifically, the first reinforcement 40 includes an upper first reinforcement 4U disposed on the upper side of the cross member 20 and a lower first reinforcement 4L disposed on the lower side of the cross member 20. Similarly, the second reinforcement 50 includes an upper second reinforcement 5U disposed on the upper side of the cross member 20 and a lower second reinforcement 5L disposed on the lower side of the cross member 20.

[0037] Hereinafter, when describing a configuration common to the upper first reinforcement 4U and the lower first reinforcement 4L, it will be simply referred to as the first reinforcement 40. Similarly, when describing a configuration common to the upper second reinforcement 5U and the lower second reinforcement 5L, it will be simply referred to as the second reinforcement 50.

[0038] 3 and 4 show an example of an arrangement in which the first reinforcement 40 and the second reinforcement 50 are provided in order from the side closest to the cross member 20. Specifically, from top to bottom, the upper second reinforcement 5U, the upper first reinforcement 4U, the cross member 20, the lower first reinforcement 4L, and the lower second reinforcement 5L are arranged in this order.

[0039] ==First Reinforce== The first reinforcement 40 is a reinforcing member that is superimposed on the cross member 20 along each of the left and right bending portions 2A. That is, the first reinforcement 40 has at least a portion that is along the bending portion 2A. Because the left and right first reinforcements 40 are configured symmetrically, only one of the left and right first reinforcements 40 will be described. The first reinforcement 40 has a first bottom surface portion 41 extending along the bottom surface 15 of the case 12, and a first side surface portion 42 extending along the side surface 16. In the first reinforcement 40, the first bottom surface portion 41 and the first side surface portion 42 are integrally formed, and the portion along the bent portion 2A is located at the connection point (boundary) between the first bottom surface portion 41 and the first side surface portion 42.

[0040] The first reinforcement 40 can be formed by bending a single steel plate that has been punched out based on a development view, for example. In the first reinforcement 40 formed in this manner, a first bottom surface portion 41 along the bottom surface 15 and a first side surface portion 42 along the side surface 16 are butted together, resulting in a bent shape similar to that of the bent portion 2A. 3 is formed along the bottom portion 2D and each wall portion 2E of the cross member 20. Speaking in detail about the upper first reinforcement 4U, the upper first reinforcement 4U is placed in a recess formed by the bottom portion 2D and each wall portion 2E of the cross member 20. In addition, the portion of the upper first reinforcement 4U that faces each wall portion 2E (the edge, so to speak) is arranged to abut against each wall portion 2E of the cross member 20.

[0041] In addition, the lower first reinforcement 4L exemplified here has ribs 49 on both the front and rear sides that extend in the vehicle width direction and protrude downward. In this way, the ribs 49 extending in the vehicle width direction on both the front and rear sides of the lower first reinforcement 4L can be said to be portions that increase the rigidity of the lower first reinforcement 4L, and may also be called protrusions. Between the two ribs 49, a welding point (so-called bead) for fixing the lower first reinforcement 4L to the cross member 20 is provided.

[0042] ==Second Reinforce== The second reinforcement 50 is a reinforcing member that is superimposed on at least a part of the left and right first reinforcements 40 and the inner portion 2B. Since the left and right second reinforcements 50 are configured symmetrically, only one of the left and right second reinforcements 50 will be described. The second reinforcement 50 has a first portion 51 that overlaps with at least a part of the portion of the first reinforcement 40 that extends along the bent portion 2A in a plan view, and a second portion 52 that extends inward in the vehicle width direction from the first portion 51. Note that "at least a part of the portion that extends along the bent portion 2A of the first reinforcement 40" here means at least a part of the portion of the first reinforcement 40 that extends along the bent portion 2A of the cross member 20. Because the bent portion 2A is a linear portion that extends in the fore-and-aft direction (or a curved surface with a small area), the first portion 51 is also at least a part of a linear region that extends in the fore-and-aft direction (or a curved surface with a small area).

[0043] 3 illustrates an example in which the entire upper second reinforcement 5U overlaps with the upper first reinforcement 4U in a plan view, and a portion of the lower second reinforcement 5L overlaps with the entire upper first reinforcement 4U in a plan view. However, a configuration in which a portion of the upper second reinforcement 5U overlaps with the upper first reinforcement 4U in a plan view, and the entire lower second reinforcement 5L overlaps with the upper first reinforcement 4U in a plan view, may also be employed.

[0044] 4, the second reinforcement 50 has a second bottom surface portion 53 extending along the bottom surface 15 of the case 12, and a second side surface portion 54 (side surface portion) extending along the side surface 16. In other words, the first portion 51 of the second reinforcement 50 is a linear region (or a curved surface with a small area) corresponding to a fold line formed by folding either the second bottom surface portion 53 or the second side surface portion 54 toward the other. The second bottom surface portion 53 is a portion that extends in a region that overlaps with the first bottom surface portion 41 of the first reinforcement 40 in a plan view. The second side surface portion 54 is a portion that extends in a region that overlaps with the first side surface portion 42 of the first reinforcement 40 in a side view.

[0045] A first bottom surface portion 41 is disposed between the second bottom surface portion 53 and the bottom surface 15 of the case 12, and a first side surface portion 42 is disposed between the second side surface portion 54 and the side surface 16 of the case 12. That is, the first reinforcement 40 is sandwiched between the first portion 51 and a corner portion 17 of the case 12. In other words, at least a portion of the first reinforcement 40 is disposed between at least a portion of the second reinforcement 50 including the first portion 51 and the cross member 20. That is, the first reinforcement 40 and the second reinforcement 50 are disposed in this order from the cross member 20 side.

[0046] As described above, the second portion 52 is a portion that extends inward in the vehicle width direction from the first portion 51, and therefore extends along the bottom surface 15 of the case 12. This second portion 52 sandwiches at least a portion of the first reinforcement 40 between itself and the bottom surface 15 of the case 12 (see FIG. 3 ), and can also be said to be a portion that faces the bottom surface 15. This second portion 52 includes a region (hereinafter also referred to as a "reinforcement wrap region") that overlaps with the battery module 11 (see FIG. 1) housed in the case 12 in a planar view. That is, at least a portion of the battery module 11 is disposed above the second portion 52. In other words, the second portion 52 extends from the second bottom surface portion 53 of the first portion 51 downward relative to at least a portion of the battery module 11. A region (hereinafter also referred to as a "case wrap region") of the bottom surface 15 of the case 12 where the reinforcement wrap region of the second portion 52 overlaps is interposed between the second portion 52 and at least a portion of the battery module 11.

[0047] ==Other== From the viewpoint of ensuring reinforcement of the cross member 20, it is preferable that all of the four reinforcements 4U, 4L, 5U, and 5L described above are overlapped with the three cross members 21, 22, and 23, respectively. However, from the viewpoint of suppressing excessive reinforcement or achieving weight reduction, for the three cross members 21, 22, 23 that have relatively high strength, some of the reinforcements 4U, 4L, 5U, 5L may be omitted or made smaller.

[0048] For example, the third cross member 23, which has a pillar provided nearby, tends to have greater strength than the first cross member 21 and the second cross member 22, which do not have a pillar provided nearby. Therefore, the application of the lower first reinforcement 4L to the third cross member 23 may be omitted, and a lower second reinforcement 5L smaller in size than that applied to the first cross member 21 and the second cross member 22 may be applied.

[0049] 1 and 4, the battery pack protective structure exemplified in this embodiment is provided with a third reinforcement 60 that is superimposed along the side member 30. Similar to the side member 30, this third reinforcement 60 is provided only on the outside of the case 12. The third reinforcement 60 is a reinforcing member for the side member 30. The third reinforcement 60 illustrated in FIG. 1 is not provided over the entire area in the extension direction (i.e., the front-to-rear direction) of the side member 30, but is provided partially. In the structure illustrated in FIG. 1, the third reinforcement 60 is not provided in the area spanning the third cross member 23, but is provided in the area spanning the first cross member 21 and the second cross member 22.

[0050] [2. Actions and Effects] The battery pack protective structure of this embodiment is configured as described above, and therefore provides the following functions and effects. (1) In the battery pack protective structure of the present embodiment, the first reinforcement 40 is overlapped on the cross member 20 along the bent portion 2A, and the first portion 51 of the second reinforcement 50 is overlapped on the first reinforcement 40. Therefore, the bent portion 2A of the cross member 20 is reinforced by the first reinforcement 40, and the first reinforcement 40 is reinforced by the first portion 51 of the second reinforcement 50. In other words, the bent portion 2A of the cross member 20 is reinforced by a double structure including not only the first reinforcement 40 but also the first portion 51 of the second reinforcement 50. By reinforcing the bent portion 2A along the corner 17 of the case 12 in this way, the corner 17 of the case 12 can be indirectly reinforced.

[0051] Additionally, the second portion 52 of the second reinforcement 50 extends to an area that overlaps with the inner portion 2B of the cross member 20 in a plan view. Therefore, the inner portion 2B of the cross member 20 is reinforced by the second portion 52 of the second reinforcement 50. By reinforcing the inner portion 2B along the bottom surface 15 of the case 12 in this manner, the bottom surface 15 of the case 12 can be indirectly reinforced. In the manner described above, corners 17 and bottom surface 15 of case 12, which are likely to be more easily deformed than other portions, can be reinforced. For example, in the event of a side collision of the vehicle, the double structure of first reinforcement 40 and first portion 51 of second reinforcement 50 effectively suppresses tilt deformation of the member, thereby suppressing tilt deformation of the case. Even if a load that deforms bottom surface 15 of case 12 is applied due to the impact of a side collision, member distortion deformation can be suppressed by second portion 52 of second reinforcement 50, thereby suppressing case distortion deformation. Therefore, the protection of the battery pack 10 can be ensured.

[0052] (2) The first portion 51 of the second reinforcement 50 has a second side surface portion 54 that extends along the side surface 16 of the case 12. In this manner, the second side surface portion 54 of not only the first reinforcement 40 but also the second reinforcement 50 extends laterally along the side surface 16 of the case 12, thereby reinforcing the portion of the first reinforcement 40 that is along the side surface 16 of the case 12. From this perspective, it is possible to suppress collapse deformation of the member and collapse deformation of the case.

[0053] (3) At least a portion of the first reinforcement 40 is disposed between at least a portion of the second reinforcement 50, including the first portion 51, and the cross member 20. By arranging the first reinforcement 40 and the second reinforcement 50 in this order from the side closest to the cross member 20, the first reinforcement 40, which reinforces the bent portion 2A, is disposed closer to the bent portion 2A than the second reinforcement 50. Therefore, by reliably reinforcing the bent portion 2A, collapsed deformation of the member and collapsed deformation of the case can be more effectively suppressed. This improves the protection of the battery pack 10.

[0054] (4) The cross member 20 is provided with an upper first reinforcement 4U and an upper second reinforcement 5U on the upper side, and a lower first reinforcement 4L and a lower second reinforcement 5L on the lower side. In this way, by providing the first reinforcement 40 and the second reinforcement 50 on both the upper and lower sides of the cross member 20, the reinforcing effect of the corners 17 and bottom surface 15 of the case 12 corresponding to the bent portion 2A and inner portion 2B of the cross member 20 is further enhanced. Therefore, the protection of the battery pack 10 is improved.

[0055] (5) The second portion 52 of the second reinforcement 50 includes a portion that overlaps with the battery module 11 housed in the case 12 in a planar view. Therefore, the reinforcement wrap region of the second portion 52 that overlaps with the battery module 11 in a planar view and the case wrap region of the bottom surface 15 on which the reinforcement wrap region overlaps are pressed down by the heavy battery module 11. Therefore, by utilizing the weight of the battery module 11, deformation of the reinforcement wrap region and the case wrap region can be suppressed. This is effective in suppressing deformation of the reinforcement wrap region and the case wrap region when an external force is input from the side of the vehicle, such as during a side collision.

[0056] (6) The side members 30 are attached across the three cross members 20, and the side members 30 reinforce each of the cross members 20, which contributes to improving the protection of the battery pack 10. (7) According to the third reinforcement 60 overlapping along the side member 30, the side member 30 is reinforced by the third reinforcement 60, which contributes to further improving the protection of the battery pack 10.

[0057] The third reinforcement 60 exemplified in this embodiment is not provided over the entire area in the extension direction of the side member 30, but is provided only in a portion thereof. Specifically, the third reinforcement 60 is not provided in the area spanning the third cross member 23, but is provided only in the area spanning the first cross member 21 and the second cross member 22. By reinforcing only a portion of the side member 30 with the third reinforcement 60 in this way, it is possible to optimize the reinforcement and suppress an increase in weight.

[0058] (8) The cross member 20 is provided with a bottom portion 2D and a wall portion 2E extending in the vehicle width direction on both front and rear sides thereof, and the first reinforcement 40 is formed along the bottom portion 2D and the wall portion 2E. Therefore, the cross member 20 can be effectively reinforced. Specifically, the first reinforcement 40 is placed in a recess formed by the bottom portion 2D and the wall portion 2E of the cross member 20, and the portion of the first reinforcement 40 facing the wall portion 2E (the edge, so to speak) is arranged to abut against the wall portion 2E of the cross member 20. Therefore, the bottom portion 2D and the wall portion 2E (the main portion, so to speak) located in the center of the cross member 20 in the fore-and-aft direction can be reliably reinforced.

[0059] (9) The lower first reinforcement 4L is provided with ribs 49 on both the front and rear sides, which extend in the vehicle width direction and protrude downward. The ribs 49 extending in the vehicle width direction on both the front and rear sides in this manner increase the rigidity of the lower first reinforcement 4L. This also improves the protection of the battery pack 10. (10) In addition, the cross member 20, the side members 30, and the reinforcements 40, 50, and 60 illustrated in the embodiment are not provided inside the case 12, but are provided only on the outside of the case 12. This allows space to be secured inside the case 12 to accommodate the battery module 11, which contributes to improving the layout efficiency inside the case 12 and ensuring battery capacity.

[0060] [II. Modifications] The above-described embodiment is merely an example. In the battery pack protective structure, it is sufficient that the first reinforcement and the second reinforcement are provided on at least one of the upper and lower sides of the cross member. For example, the first reinforcement and the second reinforcement may be provided only on the upper side or the lower side of the cross member. In this way, a battery pack protective structure in which the first reinforcement and the second reinforcement are provided only on one of the upper side and the lower side of the cross member can ensure protection of the battery pack with a simple configuration and can suppress an increase in weight.

[0061] The stacking order of the first reinforcement and the second reinforcement is not limited to the first reinforcement, second reinforcement from the side closest to the cross member, but may be the second reinforcement, first reinforcement from the side closest to the cross member. Even with such a stacking order, the first reinforcement and second reinforcement can ensure the protection of the battery pack. The shape of the cross member is not limited to a hat-shaped cross section having a flange portion, a bottom portion, and a wall portion, and any shape can be adopted.

[0062] The shape of the reinforcement can be any shape that corresponds to the shape of the object to be reinforced, such as a cross member or a side member. For example, the upper first reinforcement may also be provided with a rib similar to the rib provided on the lower first reinforcement. Alternatively, the first portion of the second reinforcement may be a portion that at least follows the bent portion of the cross member in a plan view, and the second side portion that follows the side of the case may be omitted. Such a second reinforcement can ensure protection of the battery pack with a simple configuration.

[0063] The third reinforcement may be omitted, and furthermore, the side members are not essential components. In addition, the second portion of the second reinforcement does not have to overlap with the battery module in a plan view. That is, the extension range of the second reinforcement can be set to various ranges depending on the range to be reinforced by the second reinforcement. [Industrial Applicability]

[0064] This invention can be used in the manufacturing industry of vehicles equipped with battery packs. [Explanation of symbols]

[0065] 10 Battery pack 12 cases 15 bottom 16 Side 17 Corner 20 Cross member 2A Bend part 2B Inside part 30 Side member 40 First Reinforcement 4U Upper First Reinforcement 4L Lower First Reinforcement 49 Ribs 50 Second Reinforcement 51 Part 1 52 Second part 54 Second side part (side part) 5U Upper Second Reinforcement 5L Lower Second Reinforcement 60 Third Reinforcement

Claims

1. a cross member extending along the vehicle width direction, the cross member having a bent portion that follows a corner formed by a bottom surface of a case of a battery pack to be mounted on a vehicle and a side surface located at a vehicle width direction side end of the case, and an inner portion that extends from the bent portion along the bottom surface toward the inside in the vehicle width direction; A first reinforcement member overlapped on the cross member along the bent portion at least on one of the upper and lower sides of the cross member; A second reinforcement having a first portion that overlaps with at least a portion of the portion along the bent portion of the first reinforcement in a plan view, and a second portion that extends from the first portion toward the inside in the vehicle width direction and overlaps with at least a portion of the inner portion in a plan view, and is superimposed on the cross member on at least one of the upper and lower sides of the cross member; Equipped with The first reinforcement and the second reinforcement are arranged in this order from the cross member side. A battery pack protective structure comprising:

2. The first portion has a side portion extending along the side surface.

2. The battery pack protective structure according to claim 1, wherein:

3. (delete)

4. The first reinforcement has an upper first reinforcement arranged on the upper side of the cross member and a lower first reinforcement arranged on the lower side of the cross member, The second reinforcement has an upper second reinforcement arranged on the upper side of the cross member and a lower second reinforcement arranged on the lower side of the cross member.

3. The battery pack protective structure according to claim 1 or 2.

5. The second portion includes a portion that overlaps with the battery module housed in the case in a plan view.

5. The battery pack protective structure according to claim 1, 2, or 4.

6. a side member extending in the longitudinal direction of the vehicle along the side surface and attached across the cross members arranged in parallel at intervals in the longitudinal direction; 6. The battery pack protective structure according to claim 1, 2, 4, or 5.

7. A third reinforcement is provided which is superimposed along the side member.

7. The battery pack protective structure according to claim 6, wherein:

8. The cross member has a pair of flange portions extending toward the front and rear of the vehicle, respectively, a bottom portion extending between the pair of flange portions and positioned lower than the pair of flange portions, and wall portions vertically connecting each of the pair of flange portions and the bottom portion, The first reinforcement is formed along the bottom portion and the wall portion.

8. The battery pack protective structure according to claim 1, 2, or 4 to 7.

9. The first reinforcement has ribs extending along the vehicle width direction and projecting downward on each of the front and rear sides of the vehicle.

9. The battery pack protective structure according to claim 1, 2, or 4 to 8.

10. The cross member, the first reinforcement, and the second reinforcement are provided only on the outside of the case.

10. The battery pack protective structure according to claim 1, 2, or 4 to 9.

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