Connecting structure of battery pack

Abstract

The utility model relates to a connecting structure of a battery pack. Specifically, a connection structure of a battery pack according to one form of the present disclosure comprises: a bracket to which a side end portion on a left side or a right side of the battery pack is connected; and a connecting member that connects the upper end portion of the bracket and the floor panel to each other. The connecting member includes: an inclined portion that connects the bracket and the floor panel to each other and that extends upward as the inclined portion approaches an inner side of the vehicle; and a fragile portion provided in a lower end portion of the inclined portion and having a stiffness about an axis extending in the front-rear direction of the vehicle that is lower than a stiffness of the center passage about the axis extending in the front-rear direction of the vehicle.

Description

Technical Field

[0001] The present disclosure relates to a connection structure of a battery pack, and more particularly to a connection structure that connects a battery pack disposed on the lower side of a floor panel to the floor panel, the floor panel having a central passage extending in the longitudinal direction of the vehicle. Background Art

[0002] Generally, when a battery pack is installed in a vehicle, the battery pack is connected to the vehicle's floor panel in a state of being disposed on the lower side of the floor panel. For example, in Japanese Unexamined Patent Application Publication No. 2022-111787, the battery pack is connected to the floor panel via a side frame as an energy absorption (EA) material. Summary of the Utility Model

[0003] The applicant of the present disclosure has found the following problems. In a normal floor panel, a central passage for allowing a brake pipe or the like to pass therethrough is formed to extend in the longitudinal direction of the vehicle. Regarding such a central passage, in the event of a side collision of the vehicle, so-called dropping of the central passage may occur and the central passage may be pressed downward.

[0004] The present disclosure has been made in view of the above problems, and the present disclosure provides a connection structure of a battery pack that can reduce the situation where the central passage of the floor panel is pressed downward in the event of a side collision of the vehicle.

[0005] A connection structure of a battery pack according to an aspect of the present disclosure is a connection structure that connects a battery pack disposed on the lower side of a floor panel to the floor panel, the floor panel having a central passage extending in the longitudinal direction of the vehicle, the connection structure including: a bracket to which a side end portion on the left or right side of the battery pack is connected; and a connecting member that connects the upper end portion of the bracket and the floor panel to each other. In the connection structure, the connecting member includes: an inclined portion that connects the bracket and the floor panel to each other and extends upward as it approaches the inner side of the vehicle; and a fragile portion that is provided at the lower end portion of the inclined portion and has a stiffness around an axis extending in the longitudinal direction of the vehicle, the stiffness being lower than the stiffness of the central passage around the axis extending in the longitudinal direction of the vehicle.

[0006] In the above connection structure of the battery pack, the stiffness of the bracket around an axis extending in the longitudinal direction of the vehicle may be higher than the stiffness of the fragile portion of the connecting member around the axis extending in the longitudinal direction of the vehicle.

[0007] The connection structure of the above battery pack may include a reinforcing member that connects the side end of the battery pack and the bracket to each other. In this connection structure, the stiffness of the reinforcing member around the axis extending in the front-rear direction of the vehicle may be higher than the stiffness of the bracket around the axis extending in the front-rear direction of the vehicle and the stiffness of the central passage around the axis extending in the front-rear direction of the vehicle.

[0008] In the connection structure of the above battery pack, in the left-right direction of the vehicle, a gap portion for preventing contact between the battery pack and the bracket during a side collision of the vehicle may be provided between the battery pack and the bracket.

[0009] In the connection structure of the above battery pack, the stiffness of the vulnerable portion of the connection member around the axis extending in the front-rear direction of the vehicle may be lower than the stiffness of the central passage reinforcement provided in the central passage around the axis extending in the front-rear direction of the vehicle, and the stiffness around the axis extending in the front-rear direction of the vehicle may decrease in the order of the reinforcing member, the bracket, the central passage reinforcement, and the vulnerable portion of the connection member.

[0010] According to the present disclosure, a connection structure of a battery pack can be achieved, which can reduce the situation where the central passage of the floor panel is pressed downward during a side collision of the vehicle. Description of the Drawings

[0011] Hereinafter, the features, advantages, and technical and industrial significance of exemplary embodiments of the present invention will be described with reference to the drawings, where the same reference numerals represent the same elements, and wherein:

[0012] Figure 1 is a schematic view showing the connection structure of a battery pack according to an embodiment;

[0013] Figure 2 is a perspective view showing the reinforcing member, the bracket, and the connection member in the connection structure of the battery pack according to the embodiment; and

[0014] Figure 3 is a view for describing the deformation when the vehicle is subjected to a side collision from the X-axis side in the connection structure according to the embodiment. Detailed Description of the Embodiment

[0015] Hereinafter, specific embodiments applying the present disclosure will be described in detail with reference to the drawings. However, the present disclosure is not limited to the following embodiments. For the sake of clarification, the following description and drawings are appropriately simplified.

[0016] Figure 1 is a schematic view showing the connection structure of the battery pack according to the present embodiment. Figure 2It is a perspective view showing a reinforcing member, a bracket, and a connecting member in the connection structure of the battery pack of the present embodiment. Here, in the following description, a three-dimensional (XYZ) coordinate system is used for description to clarify the description.

[0017] 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.

[0018] As Figure 1 shown, for example, when an end portion on the + side of the X-axis or an end portion on the - side of the X-axis of the battery pack 4 provided on the - side of the Z-axis with respect to the floor panel 3 of the vehicle 2 is connected to the floor panel 3, the connection structure (hereinafter may be simply referred to as the connection structure) 1 of the battery pack of the present embodiment is suitable. Therefore, the structure for connecting the end portions on the + side of the Y-axis and the - side of the Y-axis of the battery pack 4 to the floor panel 3 is not an essential part of the present disclosure, and thus the description thereof is omitted.

[0019] The connection structure 1 of the present embodiment has a line-symmetric configuration. For example, the axis of symmetry of this line-symmetric configuration is an axis that passes through the center of the vehicle 2 in the X-axis direction and is parallel to the Z-axis when viewed from the Y-axis direction. Therefore, the configuration on the + side of the X-axis is representatively described, and only a part on the + side of the X-axis of the vehicle 2 is representatively shown in Figure 1 the figure.

[0020] Here, first, the configurations of the floor panel 3 and the battery pack 4 are briefly described. As Figure 1 shown, for example, the floor panel 3 includes a central channel 3a for accommodating a brake pipe 5 and the like. The central channel 3a has a substantially isosceles trapezoidal shape. For example, when viewed from the Y-axis direction, the - side of the Z-axis is open, and the central channel 3a extends in the Y-axis direction substantially at the center of the floor panel 3 in the X-axis direction.

[0021] For example, as Figure 1 shown, the central channel 3a can be strengthened by a central channel reinforcing member 3b. For example, the central channel reinforcing member 3b is a rib member having a cross-section with a substantially inverted cap shape and extending in the X-axis direction. The central channel reinforcing member 3b is fixed to the end portion on the - side of the Z-axis of the central channel 3a by being spaced apart from the end portion by a predetermined interval in the Y-axis direction.

[0022] The battery pack 4 is a secondary battery such as a lithium-ion battery, and for example, a plurality of battery cells are accommodated in a case 4a. As Figure 1 shown, for example, the case 4a includes an upper case 4b and a lower case 4c, and is substantially airtightly sealed due to the flange portion 4d of the upper case 4b and the flange portion 4e of the lower case 4c being connected to each other.

[0023] Next, the structure of the connection structure 1 of this embodiment will be described. As Figure 1 and Figure 2 shown, the connection structure 1 includes a reinforcing member 6, a bracket 7, and a connecting member 8. The reinforcing member 6 includes a bent portion 6a, a first flange portion 6b, and a second flange portion 6c, and is, for example, a long member extending in the Y-axis direction.

[0024] As Figure 1 and Figure 2 shown, for example, the bent portion 6a has a substantially inverted C shape and is open on the X-axis side when viewed from the Y-axis direction. The width dimension of the bent portion 6a in the X-axis direction is larger than the width dimensions of the flange portion 4d of the upper housing 4b and the flange portion 4e of the lower housing 4c in the housing 4a of the battery pack 4 in the X-axis direction.

[0025] As Figure 1 and Figure 2 shown, for example, the first flange portion 6b projects from the open end portion on the +Z axis side of the bent portion 6a toward the +Z axis side. For example, the second flange portion 6c projects from the open end portion on the -Z axis side of the bent portion 6a toward the -X axis side.

[0026] As Figure 1 shown, since the first flange portion 6b is fixed to the side surface on the +X axis side of the lower housing 4c in the housing 4a of the battery pack 4 and the second flange portion 6c is fixed to the bottom surface on the -Z axis side of the lower housing 4c in the housing 4a of the battery pack 4, the reinforcing member 6 is fixed to the battery pack 4.

[0027] At this time, as Figure 1 shown, the end portion on the +X axis side of the reinforcing member 6 is disposed on the +X axis side with respect to the end portions on the +X axis side of the flange portion 4d of the upper housing 4b and the flange portion 4e of the lower housing 4c in the housing 4a of the battery pack 4.

[0028] Here, preferably, the flexural rigidity of the reinforcing member 6 about the Y axis is higher than the flexural rigidity of the central channel stiffener 3b in the floor panel 3 about the Y axis (for example, the flexural rigidity of the end portion 3d on the +Z axis side of the inclined portion 3c on the -X axis side of the central channel stiffener 3b about the Y axis).

[0029] As Figure 2 shown, for example, each bracket in the bracket 7 has a substantially cap-shaped cross section and has a substantially inverted L shape that bends to the -Z axis side after extending to the -X axis side when viewed from the Y-axis direction. In other words, the bracket 7 has a shape in which the substantially cap-shaped cross section that is open on the -Z axis side continues to the -X axis side, and then the substantially cap-shaped cross section that is open on the +X axis side continues to the -Z axis side. The bracket 7 includes a bent portion 7a, a first flange portion 7b, and a second flange portion 7c.

[0030] As Figure 2 shown, the bent portion 7a has a substantially C-shaped cross section, and preferably, for example, a part of the bent portion 7a extending toward the Z-axis - side widens in the width dimension in the Y-axis direction toward the Z-axis - side. The first flange portion 7b protrudes from the opening end portion on the Y-axis + side of the bent portion 7a toward the Y-axis + side. The second flange portion 7c protrudes from the opening end portion on the Y-axis - side of the bent portion 7a toward the Y-axis - side.

[0031] As Figure 2 shown, a plurality of brackets 7 are provided at a predetermined interval from each other in the Y-axis direction. As Figure 1 shown, since a part of the bent portion 7a extending along the Z-axis - side is connected to the end portion on the X-axis + side of the bent portion 6a of the reinforcing member 6, the bracket 7 is fixed to the battery pack 4 via the reinforcing member 6.

[0032] At this time, as Figure 1 shown, a clearance portion 9 is formed in the X-axis direction between the end portions on the X-axis + side of the flange portion 4d of the upper housing 4b and the flange portion 4e of the lower housing 4c in the housing 4a of the battery pack 4 and the bent portion 7a of the bracket 7, so that when the reinforcing member 6 is damaged during a side collision of the vehicle 2, the battery pack 4 does not contact the bracket 7.

[0033] Here, preferably, the bending rigidity of the bracket 7 around the Y-axis is higher than the bending rigidity of the center channel reinforcement 3b in the floor panel 3 around the Y-axis (for example, the bending rigidity of the end portion 3d on the Z-axis + side of the inclined portion 3c on the X-axis - side of the center channel reinforcement 3b) and lower than the bending rigidity of the reinforcing member 6 around the Y-axis.

[0034] As Figure 1 and Figure 2 shown, for example, when viewed from the Y-axis direction, the connecting member 8 has a substantially inverted hat-shaped cross section with the Z-axis + side open, and the connecting member 8 is a long member extending in the Y-axis direction. The connecting member 8 includes a bent portion 8a, a first flange portion 8b, and a second flange portion 8c.

[0035] As Figure 1 and Figure 2 shown, for example, when viewed from the Y-axis direction, the bent portion 8a has a substantially right trapezoidal shape with the Z-axis + side open. Specifically, the bent portion 8a includes a first portion 8d, a second portion 8e, and a third portion 8f.

[0036] As Figure 1 and Figure 2As shown, for example, the first part 8d is set to be substantially parallel to the YZ plane. The second part 8e extends from the end on the Z-axis side of the first part 8d toward the X-axis side, and is set to be substantially parallel to the XY plane. The third part 8f extends from the end on the X-axis side of the second part 8e toward the X-axis side, and is inclined toward the Z-axis + side as it approaches the X-axis side.

[0037] As Figure 1 and Figure 2 shown, the first flange portion 8b protrudes from the open end on the X-axis + side of the bent portion 8a toward the X-axis + side. The second flange portion 8c protrudes from the open end on the X-axis - side of the bent portion 8a toward the X-axis - side.

[0038] As Figure 1 and Figure 2 shown, since the first flange portion 8b and the second flange portion 8c are connected to the end on the Z-axis - side of the floor panel 3 and the portion of the bracket 7 extending toward the X-axis - side of the bent portion 7a is connected to the second part 8e of the bent portion 8a, the connecting member 8 connects the battery pack 4 to the floor panel 3 via the reinforcing member 6 and the bracket 7. Therefore, the third part 8f of the bent portion 8a in the connecting member 8 connects the bracket 7 and the floor panel 3 to each other.

[0039] At this time, although the detailed functions will be described below, the end 8g on the Z-axis - side of the third part 8f of the bent portion 8a in the connecting member 8 forms a vulnerable portion 8h, and the bending stiffness of the vulnerable portion 8h about the Y-axis is lower than the bending stiffness of the central channel reinforcing member 3b in the floor panel 3 (for example, the bending stiffness about the Y-axis of the end 3d on the Z-axis + side of the inclined portion 3c on the X-axis - side of the central channel reinforcing member 3b).

[0040] Here, preferably, the bending stiffness of the vulnerable portion 8h of the connecting member 8 about the Y-axis is lower than the bending stiffness of the reinforcing member 6 about the Y-axis and the bending stiffness of the bracket 7 about the Y-axis. Therefore, preferably, the bending stiffness about the Y-axis decreases in the order of the reinforcing member 6, the bracket 7, the central channel reinforcing member 3b of the floor panel 3, and the vulnerable portion 8h of the connecting member 8.

[0041] Next, the deformation when the vehicle 2 is subjected to a side collision from the X-axis - side in the connection structure 1 of the present embodiment will be described. Figure 3 is a diagram for describing the deformation when the vehicle is subjected to a side collision from the X-axis - side in the connection structure of the present embodiment. In Figure 3 it, the portion of the floor panel 3 on the X-axis + side with respect to the second flange portion 8c of the connecting member 8 is omitted.

[0042] In a conventional vehicle, when the vehicle is subjected to a side collision from the X-axis - side and the floor panel 3 deforms toward the X-axis + side, the inclined portion 3c rotates counterclockwise about the end portion 3d on the Z-axis + side of the inclined portion 3c on the X-axis - side, and the X-axis - side is the side of the center channel reinforcement 3b of the floor panel 3 that is subjected to the side collision when viewed from the Y-axis - side.

[0043] Therefore, the end portion 3e on the Z-axis - side of the inclined portion 3c on the X-axis - side of the center channel reinforcement 3b in the floor panel 3 is pressed downward toward the Z-axis - side. Therefore, a large space between the floor panel 3 and the battery pack 4 needs to be fixed so that the end portion 3e on the Z-axis - side of the inclined portion 3c does not contact the battery pack 4.

[0044] Meanwhile, the connecting structure 1 of the present embodiment is configured such that, for example, the bending stiffness of the vulnerable portion 8h of the connecting member 8 about the Y-axis is lower than the bending stiffness of the end portion 3d on the Z-axis + side of the inclined portion 3c on the X-axis - side of the center channel reinforcement 3b in the floor panel 3 about the Y-axis.

[0045] Therefore, as Figure 3 shown, the vulnerable portion 8h of the connecting member 8 deforms according to the deformation of the floor panel 3 toward the X-axis + side before the end portion 3d on the Z-axis + side of the inclined portion 3c on the X-axis - side of the center channel reinforcement 3b in the floor panel 3 deforms, and when viewed from the Y-axis - side, the third portion 8f of the bent portion 8a in the connecting member 8 rotates clockwise about the vulnerable portion 8h.

[0046] Therefore, as Figure 3 shown, the third portion 8f of the bent portion 8a of the connecting member 8 presses the floor panel 3 upward toward the Z-axis + side. Therefore, the situation where the center channel 3a of the floor panel 3 is pressed downward toward the Z-axis - side can be reduced. Therefore, for example, when the connecting structure 1 of the present embodiment is adopted, the battery pack 4 can be arranged closer to the floor panel 3 and the minimum ground height can be made higher compared with a conventional vehicle.

[0047] Here, as Figure 3 shown, when the vehicle 2 is subjected to a side collision from the X-axis - side, the bracket 7 is pressed by the battery pack 4 and the reinforcing member 6 and rotates counterclockwise when viewed from the Y-axis - side. However, when the bending stiffness about the Y-axis becomes lower in the order of the reinforcing member 6, the bracket 7, the center channel reinforcement 3b of the floor panel 3, and the vulnerable portion 8h of the connecting member 8 as described above, the situation where the reinforcing member 6 and the bracket 7 are deformed greatly before the connecting member 8 and the center channel reinforcement 3b of the floor panel 3 are deformed can be reduced.

[0048] Therefore, for example, a state can be avoided in which the reinforcing member 6 and the bracket 7 are deformed significantly before the central channel reinforcing member 3b of the floor panel 3 and the connecting member 8 are deformed, and the vulnerable portion 8h of the connecting member 8 is deformed toward the Z-axis negative side, so that the floor panel 3 cannot be sufficiently pressed upward toward the Z-axis positive side.

[0049] As described above, the connection structure 1 of the present embodiment is configured such that the bending stiffness about the Y-axis of the vulnerable portion 8h of the connecting member 8 is lower than, for example, the bending stiffness about the Y-axis of the end portion 3d on the Z-axis positive side of the inclined portion 3c on the X-axis negative side of the central channel reinforcing member 3b in the floor panel 3.

[0050] Therefore, as Figure 3 shown, before the end portion 3d on the Z-axis positive side of the inclined portion 3c on the X-axis negative side of the central channel reinforcing member 3b in the floor panel 3 is deformed, the vulnerable portion 8h of the connecting member 8 is deformed according to the deformation of the floor panel 3 toward the X-axis positive side, and when viewed from the Y-axis negative side, the third portion 8f of the bent portion 8a in the connecting member 8 rotates clockwise around the vulnerable portion 8h.

[0051] Therefore, as Figure 3 shown, the third portion 8f of the bent portion 8a of the connecting member 8 presses the floor panel 3 upward toward the Z-axis positive side. Therefore, the situation where the central channel 3a of the floor panel 3 is pressed downward toward the Z-axis negative side can be reduced. Therefore, for example, when the connection structure 1 of the present embodiment is adopted, compared with a conventional vehicle, the battery pack 4 can be arranged closer to the floor panel 3 and the minimum ground height can be made higher.

[0052] When the vehicle 2 is subjected to a side collision from the X-axis negative side, as Figure 3 shown, the bracket 7 is pressed by the battery pack 4 and the reinforcing member 6 and rotates counterclockwise when viewed from the Y-axis negative side. However, when the bending stiffness about the Y-axis decreases in the order of the reinforcing member 6, the bracket 7, the central channel reinforcing member 3b of the floor panel 3, and the vulnerable portion 8h of the connecting member 8 as described above, the situation where the reinforcing member 6 and the bracket 7 are deformed significantly before the connecting member 8 and the central channel reinforcing member 3b of the floor panel 3 are deformed can be reduced.

[0053] Therefore, for example, a state can be avoided in which the reinforcing member 6 and the bracket 7 are deformed significantly before the central channel reinforcing member 3b of the floor panel 3 and the connecting member 8 are deformed, and the vulnerable portion 8h of the connecting member 8 is deformed toward the Z-axis negative side, so that the floor panel 3 cannot be sufficiently pressed upward toward the Z-axis positive side.

[0054] In the X-axis direction, a gap portion 9 is formed between the end portions on the X-axis positive side of the flange portion 4d of the upper housing 4b and the flange portion 4e of the lower housing 4c in the housing 4a of the battery pack 4 and the bent portion 7a of the bracket 7. Therefore, as Figure 3As shown, when the vehicle 2 is side-collided and the reinforcing member 6 is damaged, the contact between the battery pack 4 and the bracket 7 can be reduced.

[0055] In the connection structure 1 of the present embodiment, the reinforcing member 6, the bracket 7, the central passage reinforcing member 3b of the floor panel 3, and the vulnerable part 8h of the connection member 8 are each configured to have a bending stiffness around the Y-axis that decreases in the above order. However, the order of the bracket 7 and the central passage reinforcing member 3b of the floor panel 3 can be reversed.

[0056] Note that the connection structure 1 of the embodiment only needs to have a structure in which at least the vulnerable part 8h of the connection member 8 has a bending stiffness around the Y-axis lower than that of the central passage reinforcing member 3b in the floor panel 3 around the Y-axis.

[0057] When the floor panel 3 does not include the central passage reinforcing member 3b, the central passage reinforcing member 3b can be interpreted as the central passage 3a in the above description.

[0058] In the connection structure 1 of the present embodiment, the structures of the reinforcing member 6, the bracket 7, etc. are exemplary, and only a structure in which the end of the battery pack 4 on the +X side can be connected to the connection member 8 needs to be provided. The structure of the connection member 8 is also an example, and the connection member 8 only needs to include at least the third part 8f having the bent part 8a and the vulnerable part 8h.

[0059] The present disclosure is not limited to the above embodiments and can be appropriately changed without departing from the gist.

Claims

1. A connection structure for a battery pack, the battery pack being disposed on a lower side of a floor panel having a central passage extending in a longitudinal direction of a vehicle, the connection structure connecting the battery pack to the floor panel, characterized in that, The connecting structure includes: a bracket to which a side end portion on the left or right side of the battery pack is connected; and a connecting member that connects the upper end portion of the bracket and the floor panel to each other, wherein the connecting member includes: an inclined portion that connects the bracket and the floor panel to each other and extends upward as it approaches the inner side of the vehicle; and a fragile portion provided at the lower end portion of the inclined portion, and the stiffness of the fragile portion around an axis extending in the longitudinal direction of the vehicle is lower than the stiffness of the center tunnel around the axis extending in the longitudinal direction of the vehicle.

2. The connection structure of the battery pack according to claim 1, wherein, The stiffness of the bracket around the axis extending in the longitudinal direction of the vehicle is higher than the stiffness of the fragile portion of the connecting member around the axis extending in the longitudinal direction of the vehicle.

3. The connection structure of the battery pack according to claim 2, wherein including a reinforcing member that connects the side end portion of the battery pack and the bracket to each other, wherein the stiffness of the reinforcing member around the axis extending in the longitudinal direction of the vehicle is higher than the stiffness of the bracket around the axis extending in the longitudinal direction of the vehicle and the stiffness of the center tunnel around the axis extending in the longitudinal direction of the vehicle.

4. The connection structure of the battery pack according to claim 3, characterized in that, A gap portion is provided between the battery pack and the bracket in the left - right direction of the vehicle to prevent contact between the battery pack and the bracket during a side collision of the vehicle.

5. The connecting structure of the battery pack according to claim 3 or 4, wherein: the stiffness of the fragile portion of the connecting member around the axis extending in the longitudinal direction of the vehicle is lower than the stiffness of a center tunnel reinforcing member provided in the center tunnel around the axis extending in the longitudinal direction of the vehicle; and the stiffness around the axis extending in the longitudinal direction of the vehicle decreases in the order of the reinforcing member, the bracket, the center tunnel reinforcing member, and the fragile portion of the connecting member.

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