Battery pack connection structure

Abstract

To realize a battery pack connection structure capable of suppressing downward displacement of a center tunnel of a floor panel during a side collision of a vehicle.SOLUTION: A connection structure (1) of a battery pack (4) comprises a bracket (7) which is connected to either a left edge section or a right edge section of the battery pack (4) and a connection member (8) which connects an upper edge section of the bracket (7) to a floor panel (3). The connection member (8) has an inclined section which connects the bracket (7) and the floor panel (3) and is upwardly extended as the same goes toward an inside of a vehicle (2) and a fragile section (8h) which is arranged at a lower edge section of the inclined section and has lower rigidity around a shaft extended in a longitudinal direction of the vehicle (2) than the rigidity around the shaft extended in the longitudinal direction of the vehicle (2) in a center tunnel (3a).SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present disclosure relates to a connection structure of a battery pack, for example, to a connection structure for connecting a battery pack disposed below a floor panel having a center tunnel extending in the longitudinal direction of a vehicle to the floor panel.

Background Art

[0002] Generally, when mounting a battery pack on a vehicle, the battery pack is connected to the floor panel while being disposed below the floor panel of the vehicle. For example, in Patent Document 1, the battery pack is connected to the floor panel via a side frame which is an EA (Energy Absorption) material.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] The applicant of the present application has found the following problems. In a general floor panel, a center tunnel for passing brake pipes or the like is formed so as to extend in the longitudinal direction of the vehicle. Such a center tunnel may be so-called toppled down when the vehicle is side-collided, and the center tunnel may be pushed downward.

[0005] The present disclosure has been made in view of such problems, and realizes a connection structure of a battery pack capable of suppressing the center tunnel of the floor panel from being pushed downward when the vehicle is side-collided.

Means for Solving the Problems

[0006] The connection structure of a battery pack according to an aspect of the present disclosure is a connection structure for connecting a battery pack disposed below a floor panel having a center tunnel extending in the front-rear direction of a vehicle to the floor panel, a bracket to which one of the left and right side end portions of the battery pack is connected, a connecting member that connects an upper end portion of the bracket and the floor panel, and includes: The connecting member connects the bracket and the floor panel, and has an inclined portion that slopes upward as it goes inward of the vehicle, is disposed at a lower end portion of the inclined portion, and has a vulnerable portion having lower rigidity about an axis extending in the front-rear direction of the vehicle than the rigidity about an axis extending in the front-rear direction of the vehicle in the center tunnel, and includes:

[0007] In the above-described connection structure of the battery pack, it is preferable that the rigidity about an axis extending in the front-rear direction of the vehicle in the bracket is higher than the rigidity about an axis extending in the front-rear direction of the vehicle in the vulnerable portion of the connecting member.

[0008] The above-described connection structure of the battery pack includes a reinforcing member that connects a side end portion of the battery pack and the bracket, and it is preferable that the rigidity about an axis extending in the front-rear direction of the vehicle in the reinforcing member is higher than the rigidity about an axis extending in the front-rear direction of the vehicle in the bracket and the rigidity about an axis extending in the front-rear direction of the vehicle in the center tunnel.

[0009] In the above-described connection structure of the battery pack, in the left-right direction of the vehicle, it is preferable that a gap portion for preventing contact between the battery pack and the bracket during a side collision of the vehicle is formed between the battery pack and the bracket.

[0010] In the above-described connection structure of the battery pack, the rigidity around the axis extending in the longitudinal direction of the vehicle at the vulnerable part of the connection member is lower than the rigidity around the axis extending in the longitudinal direction of the vehicle in the center tunnel reinforcement provided in the center tunnel, It is preferable that the rigidity around the axis extending in the longitudinal direction of the vehicle is high in the order of the reinforcing member, the bracket, the center tunnel reinforcement, and the vulnerable part of the connection member.

Effect of the Invention

[0011] According to the present disclosure, it is possible to realize a connection structure of a battery pack that can suppress the center tunnel of the floor panel from being pushed downward during a side collision of a vehicle.

Brief Description of the Drawings

[0012]

Figure 1

Figure 2

Figure 3

Mode for Carrying Out the Invention

[0013] Hereinafter, specific embodiments to which the present disclosure is applied will be described in detail with reference to the drawings. However, the present disclosure is not limited to the following embodiments. Also, for clarity of explanation, the following description and drawings are appropriately simplified.

[0014] FIG. 1 is a schematic diagram showing a connection structure of a battery pack according to the present embodiment. FIG. 2 is a perspective view showing a reinforcing member, a bracket, and a connection member in the connection structure of the battery pack according to the present embodiment. Here, in the following description, for clarity of explanation, a three-dimensional (XYZ) coordinate system will be used for the explanation.

[0015] At this time, the + side of the X-axis is the right side of the vehicle, the - side of the X-axis is the left side of the vehicle, the + side of the Y-axis is the front side of the vehicle, the - side of the Y-axis is the rear side of the vehicle, the + side of the Z-axis is the upper side of the vehicle, and the - side of the Z-axis is the lower side of the vehicle.

[0016] The connection structure (hereinafter, may be simply referred to as the connection structure) 1 of the battery pack according to the present embodiment is suitable, for example, when connecting the + side end or the - side end of the X-axis of the battery pack 4 disposed on the - side of the Z-axis to the floor panel 3 of the vehicle 2 as shown in FIG. 1. Therefore, since the structure for connecting the + side end and the - side end of the Y-axis of the battery pack 4 to the floor panel 3 is not an essential part of the present disclosure, the description thereof is omitted.

[0017] Note that the connection structure 1 of the present embodiment has a line-symmetric configuration with an axis passing through the center in the X-axis direction in the vehicle 2 as viewed from the Y-axis direction and parallel to the Z-axis as the axis of symmetry. Therefore, the configuration on the + side of the X-axis is described as a representative, and in FIG. 1, only the portion on the + side of the X-axis of the vehicle 2 is shown as a representative.

[0018] Here, first, the configurations of the floor panel 3 and the battery pack 4 will be briefly described. The floor panel 3 includes, for example, a center tunnel 3a for accommodating the brake pipe 5 and the like as shown in FIG. 1. The center tunnel 3a has a substantially isosceles trapezoidal shape with the - side of the Z-axis open as viewed from the Y-axis direction, and extends in the Y-axis direction at substantially the center in the X-axis direction of the floor panel 3.

[0019] The center tunnel 3a is preferably reinforced by a center tunnel lean force 3b, for example, as shown in FIG. 1. The center tunnel lean force 3b has a substantially inverted hat-shaped cross section and is a rib member extending in the X-axis direction. The center tunnel lean force 3b is fixed to the - side end of the center tunnel 3a at a predetermined interval in the Y-axis direction.

[0020] The battery pack 4 is a secondary battery such as a lithium-ion battery, and a plurality of battery cells are housed inside the case 4a. The case 4a includes, for example, an upper case 4b and a lower case 4c as shown in FIG. 1, and is substantially sealed by connecting the flange portion 4d of the upper case 4b and the flange portion 4e of the lower case 4c.

[0021] Next, the configuration of the connection structure 1 of the present embodiment will be described. As shown in FIGS. 1 and 2, the connection structure 1 includes a reinforcing member 6, a bracket 7, and a connecting member 8. The reinforcing member 6 includes, for example, a bent portion 6a, a first flange portion 6b, and a second flange portion 6c, and is a long member extending in the Y-axis direction.

[0022] The bent portion 6a has, for example, a substantially reverse C shape with the X-axis side open as viewed from the Y-axis direction as shown in FIGS. 1 and 2. The width dimension of the bent portion 6a in the X-axis direction is wider than the width dimensions of the flange portion 4d of the upper case 4b and the flange portion 4e of the lower case 4c in the case 4a of the battery pack 4 in the X-axis direction.

[0023] The first flange portion 6b protrudes from the open end portion on the +Z side of the bent portion 6a to the +Z side as shown in FIGS. 1 and 2. The second flange portion 6c protrudes from the open end portion on the -Z side of the bent portion 6a to the -X side.

[0024] As shown in FIG. 1, the reinforcing member 6 is fixed to the battery pack 4 by fixing the first flange portion 6b to the side surface on the +X side of the lower case 4c in the case 4a of the battery pack 4 and fixing the second flange portion 6c to the bottom surface on the -Z side of the lower case 4c in the case 4a of the battery pack 4.

[0025] At this time, the end portion on the +X side of the reinforcing member 6 is arranged on the +X side with respect to the end portions on the +X side of the flange portion 4d of the upper case 4b and the flange portion 4e of the lower case 4c in the case 4a of the battery pack 4 as shown in FIG. 1.

[0026] Here, the bending rigidity of the reinforcing member 6 around the Y-axis is preferably higher than the bending rigidity around the Y-axis of the center tunnel lean force 3b in the floor panel 3 (for example, the bending rigidity around the Y-axis of the end portion 3d on the +Z-axis side of the inclined portion 3c on the X-axis side of the center tunnel lean force 3b).

[0027] The bracket 7 is, for example, as shown in FIG. 2, in a substantially cross-sectional hat shape, and has a substantially inverted L shape that extends to the X-axis side when viewed from the Y-axis direction and then is bent to the Z-axis side. That is, the bracket 7 has a shape in which a substantially cross-sectional hat shape with the Z-axis side open is continuous to the X-axis side, and then a substantially cross-sectional hat shape with the X-axis + side open is continuous to the Z-axis side. The bracket 7 includes a bent portion 7a, a first flange portion 7b, and a second flange portion 7c.

[0028] The bent portion 7a is, as shown in FIG. 2, in a substantially cross-sectional C shape. For example, the width dimension in the Y-axis direction of the portion extending to the Z-axis side in the bent portion 7a may widen toward the Z-axis side. The first flange portion 7b protrudes from the open end portion on the +Y-axis side of the bent portion 7a to the +Y-axis side. The second flange portion 7c protrudes from the open end portion on the -Y-axis side of the bent portion 7a to the -Y-axis side.

[0029] As shown in FIG. 2, a plurality of brackets 7 are arranged at a predetermined interval in the Y-axis direction. And as shown in FIG. 1, the bracket 7 is fixed to the battery pack 4 via the reinforcing member 6 by connecting the portion extending to the Z-axis side in the bent portion 7a of the bracket 7 to the end portion on the +X-axis side of the bent portion 6a of the reinforcing member 6.

[0030] At this time, when the reinforcing member 6 is damaged during a side collision of the vehicle 2, a gap portion 9 is formed between the end portions on the +X-axis side of the flange portion 4d of the upper case 4b and the flange portion 4e of the lower case 4c in the case 4a of the battery pack 4 and the bent portion 7a of the bracket 7 in the X-axis direction so that the battery pack 4 does not contact the bracket 7, as shown in FIG. 1.

[0031] Here, the bending rigidity of the bracket 7 around the Y-axis is preferably higher than the bending rigidity of the center tunnel lean force 3b in the floor panel 3 (for example, the bending rigidity around the Y-axis of the end portion 3d on the +Z side of the inclined portion 3c on the X-axis side of the center tunnel lean force 3b), and lower than the bending rigidity of the reinforcing member 6 around the Y-axis.

[0032] The connecting member 8 is, for example, as shown in FIGS. 1 and 2, a long member extending in the Y-axis direction and having a substantially inverted hat cross-sectional shape with the +Z side open when viewed from the Y-axis direction. The connecting member 8 includes a bent portion 8a, a first flange portion 8b, and a second flange portion 8c.

[0033] The bent portion 8a is, for example, as shown in FIGS. 1 and 2, a substantially right trapezoidal shape with the +Z side open when viewed from the Y-axis direction. Specifically, the bent portion 8a includes a first portion 8d, a second portion 8e, and a third portion 8f.

[0034] The first portion 8d is arranged substantially parallel to the YZ plane, for example, as shown in FIGS. 1 and 2. The second portion 8e extends from the end portion on the -Z side of the first portion 8d toward the -X side and is arranged substantially parallel to the XY plane. The third portion 8f extends from the end portion on the -X side of the second portion 8e toward the -X side and is inclined toward the +Z side as it goes toward the -X side.

[0035] The first flange portion 8b protrudes toward the +X side from the open end portion on the +X side of the bent portion 8a, as shown in FIGS. 1 and 2. The second flange portion 8c protrudes toward the -X side from the open end portion on the -X side of the bent portion 8a.

[0036] As shown in FIGS. 1 and 2, the connecting member 8 has a first flange portion 8b and a second flange portion 8c connected to the Z-axis - side end of the floor panel 3, and a portion of the bent portion 7a of the bracket 7 extending to the X-axis + side is connected to the second portion 8e of the bent portion 8a of the connecting member 8. Thus, the battery pack 4 is connected to the floor panel 3 via the reinforcing member 6 and the bracket 7. Therefore, the third portion 8f of the bent portion 8a of the connecting member 8 connects the bracket 7 and the floor panel 3.

[0037] At this time, although the detailed functions will be described later, the Z-axis - side end 8g of the third portion 8f of the bent portion 8a of the connecting member 8 forms a vulnerable portion 8h with low bending rigidity about the Y-axis with respect to the bending rigidity about the Y-axis of the center tunnel reinforcement 3b of the floor panel 3 (for example, the bending rigidity about the Y-axis of the Z-axis + side end 3d of the X-axis - side inclined portion 3c of the center tunnel reinforcement 3b of the floor panel 3).

[0038] Here, the bending rigidity about the Y-axis of the vulnerable portion 8h of the connecting member 8 is preferably low with respect to the bending rigidity about the Y-axis of the reinforcing member 6 and the bending rigidity about the Y-axis of the bracket 7. As a result, the bending rigidity about the Y-axis is preferably high in the order of the reinforcing member 6, the bracket 7, the center tunnel reinforcement 3b of the floor panel 3, and the vulnerable portion 8h of the connecting member 8.

[0039] Next, the deformation when the vehicle 2 receives a side collision from the X-axis + side in the connecting structure 1 of the present embodiment will be described. FIG. 3 is a diagram for explaining the deformation when the vehicle receives a side collision from the X-axis + side in the connecting structure of the present embodiment. In FIG. 3, the portion on the X-axis + side with respect to the second flange portion 8c of the connecting member 8 on the floor panel 3 is omitted.

[0040] In a general vehicle, when the vehicle receives a side collision from the X-axis - side and the floor panel 3 is deformed to the X-axis + side, the inclined portion 3c on the X-axis - side of the center tunnel reinforcement 3b of the floor panel 3, which is the side receiving the side collision, rotates counterclockwise as viewed from the Y-axis - side about the Z-axis + side end 3d of the inclined portion 3c.

[0041] As a result, since the Z-axis-side end 3e of the X-axis-side inclined portion 3c of the center tunnel reinforcement 3b in the floor panel 3 is pushed downward on the Z-axis side, it is necessary to secure a wide space between the floor panel 3 and the battery pack 4 so that the Z-axis-side end 3e of the inclined portion 3c does not contact the battery pack 4.

[0042] On the other hand, in the connection structure 1 of the present embodiment, for example, the brittle portion 8h of the connection member 8 has a lower bending rigidity about the Y-axis than the bending rigidity about the Y-axis of the Z-axis + side end 3d of the X-axis-side inclined portion 3c of the center tunnel reinforcement 3b in the floor panel 3.

[0043] Therefore, as shown in FIG. 3, before the Z-axis + side end 3d of the X-axis-side inclined portion 3c of the center tunnel reinforcement 3b in the floor panel 3 is deformed, the brittle portion 8h of the connection member 8 is deformed as the floor panel 3 deforms toward the X-axis + side, and the third portion 8f of the bent portion 8a in the connection member 8 rotates clockwise when viewed from the Y-axis - side around the brittle portion 8h.

[0044] As a result, the third portion 8f of the bent portion 8a of the connection member 8 pushes the floor panel 3 upward on the Z-axis + side as shown in FIG. 3. Therefore, it is possible to suppress the center tunnel 3a of the floor panel 3 from being pushed downward on the Z-axis side. As a result, when the connection structure 1 of the present embodiment is adopted as compared with a general vehicle, for example, the battery pack 4 can be arranged closer to the floor panel 3, and the minimum ground clearance can be increased.

[0045] Here, when the vehicle 2 receives a side collision from the X-axis - side, as shown in FIG. 3, the bracket 7 rotates counterclockwise as it is pushed by the battery pack 4 and the reinforcing member 6 when viewed from the Y-axis - side. However, as described above, when the bending rigidity about the Y-axis is high in the order of the reinforcing member 6, the bracket 7, the center tunnel reinforcement 3b of the floor panel 3, and the brittle portion 8h of the connection member 8, it is possible to suppress the large deformation of the reinforcing member 6 and the bracket 7 before the connection member 8 and the center tunnel reinforcement 3b of the floor panel 3 are deformed.

[0046] Therefore, for example, before the connecting member 8 and the center tunnel lean force 3b of the floor panel 3 are deformed, the reinforcing member 6 and the bracket 7 are greatly deformed, and the vulnerable portion 8h of the connecting member 8 is displaced to the Z-axis - side, and as a result, a state in which the floor panel 3 cannot be sufficiently pushed up to the Z-axis + side can be avoided.

[0047] As described above, the connecting structure 1 of the present embodiment is configured such that, for example, the vulnerable portion 8h of the connecting member 8 has a lower bending rigidity about the Y-axis than the bending rigidity about the Y-axis of the end portion 3d on the Z-axis + side of the inclined portion 3c on the X-axis - side of the center tunnel lean force 3b in the floor panel 3.

[0048] Therefore, as shown in FIG. 3, before the end portion 3d on the Z-axis + side of the inclined portion 3c on the X-axis - side of the center tunnel lean force 3b in the floor panel 3 is deformed, the vulnerable portion 8h of the connecting member 8 is deformed as the floor panel 3 deforms toward the X-axis + side, and the third portion 8f of the bent portion 8a in the connecting member 8 rotates clockwise when viewed from the Y-axis - side with the vulnerable portion 8h as the center.

[0049] Thereby, the third portion 8f of the bent portion 8a of the connecting member 8 pushes up the floor panel 3 to the Z-axis + side as shown in FIG. 3. Therefore, it is possible to suppress the center tunnel 3a of the floor panel 3 from being pushed down to the Z-axis - side. As a result, when the connecting structure 1 of the present embodiment is adopted as compared with a general vehicle, for example, the battery pack 4 can be disposed closer to the floor panel 3, and the minimum ground clearance can be increased.

[0050] Further, when the vehicle 2 receives a side collision from the X-axis - side, as shown in FIG. 3, the bracket 7 rotates counterclockwise when pushed by the battery pack 4 and the reinforcing member 6 when viewed from the Y-axis - side. However, as described above, when the bending rigidity about the Y-axis is high in the order of the reinforcing member 6, the bracket 7, the center tunnel lean force 3b of the floor panel 3, and the vulnerable portion 8h of the connecting member 8, it is possible to suppress the large deformation of the reinforcing member 6 and the bracket 7 before the connecting member 8 and the center tunnel lean force 3b of the floor panel 3 are deformed.

[0051] Therefore, for example, before the connecting member 8 or the center tunnel reinforcement 3b of the floor panel 3 is deformed, the reinforcing member 6 and the bracket 7 are greatly deformed, the vulnerable part 8h of the connecting member 8 is displaced to the Z-axis - side, and as a result, a state where the floor panel 3 cannot be sufficiently pushed up to the Z-axis + side can be avoided.

[0052] Moreover, in the X-axis direction, a gap 9 is formed between the end portions on the X-axis + side of the flange portion 4d of the upper case 4b and the flange portion 4e of the lower case 4c in the case 4a of the battery pack 4, and the bent portion 7a of the bracket 7. Therefore, as shown in FIG. 3, when the vehicle 2 receives a side collision and the reinforcing member 6 is damaged, contact between the battery pack 4 and the bracket 7 can be suppressed.

[0053] In the connecting structure 1 of the above-described embodiment, the bending rigidity around the Y-axis is configured to be high in the order of the reinforcing member 6, the bracket 7, the center tunnel reinforcement 3b of the floor panel 3, and the vulnerable part 8h of the connecting member 8, but the order of the bracket 7 and the center tunnel reinforcement 3b of the floor panel 3 may be reversed.

[0054] However, the connecting structure 1 of the above-described embodiment only needs to be configured such that the bending rigidity around the Y-axis of the vulnerable part 8h of the connecting member 8 is lower than the bending rigidity around the Y-axis of the center tunnel reinforcement 3b in the floor panel 3.

[0055] Also, when the floor panel 3 does not include the center tunnel reinforcement 3b, the center tunnel reinforcement 3b can be read as the center tunnel 3a in the above description.

[0056] In the connecting structure 1 of the above-described embodiment, the configurations such as the reinforcing member 6 and the bracket 7 are examples, and any configuration can be used as long as the end portion on the X-axis + side of the battery pack 4 can be connected to the connecting member 8. Also, the configuration of the connecting member 8 is also an example, and the connecting member 8 only needs to include at least the third portion 8f and the vulnerable part 8h of the bent portion 8a.

[0057] The present disclosure is not limited to the above embodiments, and can be appropriately modified without departing from the gist thereof.

Explanation of Signs

[0058] 1 Connection structure of battery pack 2 Vehicle 3 Floor panel, 3a Center tunnel, 3b Center tunnel lean force, 3c Inclined portion, 3d End portion on the +Z side of the inclined portion on the -X side of the center tunnel lean force, 3e End portion on the -Z side of the inclined portion on the -X side of the center tunnel lean force 4 Battery pack, 4a Case, 4b Upper case, 4c Lower case, 4d Flange portion of the upper case, 4e Flange portion of the lower case 5 Brake pipe 6 Reinforcing member, 6a Bent portion, 6b First flange portion, 6c Second flange portion 7 Bracket, 7a Bent portion, 7b First flange portion, 7c Second flange portion 8 Connecting member, 8a Bent portion, 8b First flange portion, 8c Second flange portion, 8d First portion, 8e Second portion, 8f Third portion, 8g End portion on the -Z side of the third portion of the bent portion in the connecting member, 8h Weak portion 9 Gap portion

Claims

1. A connecting structure for connecting a battery pack disposed below a floor panel having a center tunnel extending in the longitudinal direction of a vehicle to the floor panel, a bracket to which one of the left and right side end portions of the battery pack is connected, a connecting member that connects an upper end portion of the bracket and the floor panel, comprising: the connecting member connects the bracket and the floor panel, and has an inclined portion that slopes upward as it goes inward of the vehicle, is disposed at a lower end portion of the inclined portion, and is a vulnerable portion having a lower rigidity about an axis extending in the longitudinal direction of the vehicle than the rigidity about an axis extending in the longitudinal direction of the vehicle in the center tunnel, A connecting structure for a battery pack, comprising:

2. The rigidity about an axis extending in the longitudinal direction of the vehicle in the bracket is higher than the rigidity about an axis extending in the longitudinal direction of the vehicle in the vulnerable portion of the connecting member. The connecting structure for a battery pack according to Claim 1.

3. Comprising a reinforcing member that connects a side end portion of the battery pack and the bracket, The rigidity about an axis extending in the longitudinal direction of the vehicle in the reinforcing member is higher than the rigidity about an axis extending in the longitudinal direction of the vehicle in the bracket and the rigidity about an axis extending in the longitudinal direction of the vehicle in the center tunnel. The connecting structure for a battery pack according to Claim 2.

4. In the left-right direction of the vehicle, a gap portion is formed between the battery pack and the bracket to prevent contact between the battery pack and the bracket during a side collision of the vehicle. The connecting structure for a battery pack according to Claim 3.

5. The rigidity about an axis extending in the longitudinal direction of the vehicle in the vulnerable portion of the connecting member is lower than the rigidity about an axis extending in the longitudinal direction of the vehicle in a center tunnel lean force provided in the center tunnel, The rigidity about an axis extending in the longitudinal direction of the vehicle is high in the order of the reinforcing member, the bracket, the center tunnel lean force, and the vulnerable portion of the connecting member. The connecting structure for a battery pack according to Claim 3 or 4.

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