Battery pack

Abstract

The invention relates to a battery pack. The battery pack includes an upper cover and a lower case. The upper cover is disposed so as to face the floor of the vehicle. The lower housing is combined with the upper cover. In the width direction of the vehicle, the opening edge portion of the lower housing is combined with the left end portion and the right end portion of the upper cover to form a left flange and a right flange respectively. In the width direction of the vehicle, the upper surfaces of the left flange and the right flange are located below the upper surface of the upper cover facing the floor. The upper surface of the upper cover opposite to the floor and the upper surfaces of the left flange and the right flange form steps.

Description

Technical Field

[0001] The present disclosure relates to a battery pack that houses a battery stack mounted on a vehicle. Background Art

[0002] Japanese Patent No. 6451685 discloses a mounting structure for a battery pack mounted on the underbody of a vehicle. In this conventional structure, the underbody includes a floor mounted on a skeleton member of the vehicle. The battery pack includes an upper cover arranged opposite to the floor, and a lower shell combined with the upper cover. The battery stack is accommodated in the space formed between the upper cover and the lower shell. In addition, frames are respectively provided on the side surfaces of the battery pack on the front and rear sides of the vehicle. The battery pack is mounted on the skeleton member via these frames. That is, in the conventional structure, the battery pack is mounted on the underbody at the position of the skeleton member on the front and rear sides of the vehicle. Summary of the invention

[0003] Consider the point that the battery pack is mounted on the left and right frame members of the vehicle. In this case, it is important to maintain the structure of the battery pack when an external force is input from the left or right direction. However, since the upper cover of the battery pack of the conventional structure is a simple plate-shaped member, there is a problem that the mating surface of the upper cover and the lower shell is easy to open.

[0004] One object of the present disclosure is to provide a battery pack that is highly resistant to external force input from the left or right direction of a vehicle when the battery pack is mounted on frame members on the left and right sides of the vehicle.

[0005] The present invention discloses a battery pack for accommodating a battery stack mounted on a vehicle, and has the following features: The battery pack includes an upper cover and a lower shell. The upper cover is arranged opposite to the floor of the vehicle. The lower shell is combined with the upper cover.

[0006] In the width direction of the vehicle, the opening edge of the lower shell is combined with the left end and the right end of the upper cover to form a left flange and a right flange respectively. The left flange is mounted on the left frame member of the vehicle provided on the left side of the floor. The right flange is mounted on the right frame member of the vehicle provided on the right side of the floor.

[0007] In the width direction, the upper surfaces of the left and right flanges are located below the upper surface of the upper cover facing the floor. The upper surface of the upper cover facing the floor forms a step (height difference) with the upper surfaces of the left and right flanges.

[0008] According to the battery pack disclosed herein, the upper surface of the upper cover forms a step with the upper surfaces of the left flange and the right flange, so that the step can resist the external force input from the left or right direction of the vehicle to suppress the opening of the mating surface between the upper cover and the lower shell. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Features, advantages, and technical and industrial significance of exemplary embodiments of the present invention will be described below with reference to the accompanying drawings, in which like reference numerals represent like elements, and in which:

[0010] Figure 1 It is a diagram showing an example of arrangement of a battery pack according to an embodiment of the present disclosure.

[0011] Figure 2 It is a diagram for explaining a configuration example of a battery pack according to an embodiment.

[0012] Figure 3 Yes means Figure 2 A diagram of the characteristic portions of a battery pack is shown.

[0013] Figure 4 It is a diagram for explaining the effects of the battery pack according to the embodiment.

[0014] Figure 5 It is a diagram for explaining the effects of the battery pack according to the embodiment.

[0015] Figure 6 It is a diagram for explaining the effects of the battery pack according to the embodiment. DETAILED DESCRIPTION

[0016] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. However, the structures and the like described in the embodiments shown below are not necessarily essential to the present invention unless otherwise specifically stated or clearly determined in principle as such structures.

[0017] 1. Battery Pack

[0018] Figure 1 It is a diagram showing an example of arrangement of a battery pack 1 according to an embodiment of the present disclosure. Figure 2 1 is a diagram for explaining a configuration example of the battery pack 1. Figure 1 The X-axis shown corresponds to the front-rear direction (length direction) of the vehicle VH. Figure 1 and Figure 2 The Y axis shown corresponds to the left-right direction (width direction) of the vehicle VH. Figure 2 The Z axis shown corresponds to the up-down direction (height direction) of the vehicle VH. More specifically, the positive direction of the X axis corresponds to the front direction, the positive direction of the Y axis corresponds to the right direction, and the positive direction of the Z axis corresponds to the upward direction.

[0019] like Figure 1 and Figure 2 As shown, the battery pack 1 is mounted on the underbody 2 of the vehicle VH. The underbody 2 includes a right frame member (right side frame) 21, a left frame member (left side frame) 22, and a floor 23. The floor 23 is mounted between the right frame member 21 and the left frame member 22. The mounting position of the battery pack 1 and the underbody 2 is the lower surface of the right frame member 21 and the left frame member 22 (that is, the position outside the vehicle cabin). For example, the battery pack 1 is mounted on the underbody 2 by a fastening member that connects the lower surface of the battery pack 1 to the upper surface of the underbody 2.

[0020] like Figure 2 As shown, the battery pack 1 includes an upper cover 11 and a lower shell 12. The upper cover 11 is composed of a central portion 11a, a right end portion 11b, and a left end portion 11c. The central portion 11a is opposite to the floor 23. The right end portion 11b is opposite to the right frame member 21. The left end portion 11c is opposite to the left frame member 22. The upper surface of the central portion 11a is located above the upper surfaces of the right end portion 11b and the left end portion 11c. The upper surface of the central portion 11a forms a step with the upper surfaces of the right end portion 11b and the left end portion 11c.

[0021] The lower housing 12 is composed of a housing portion 12a and an opening edge portion 12b extending in the left-right direction of the vehicle VH at the opening position of the housing portion 12a. The lower housing 12 is combined with the upper cover 11. The battery stack 3 is accommodated in a space 13 surrounded by the lower surface of the central portion 11a and the upper surface and side surfaces of the housing portion 12a. The battery stack 3 is formed by stacking a plurality of single cells. Figure 2 In the example shown, the stacking direction of the plurality of cells is the width direction of the vehicle VH. The battery stack 3 is a secondary battery that can be charged and discharged, and a lithium ion secondary battery is exemplified as such a secondary battery.

[0022] The upper cover 11 and the lower shell 12 are combined at positions where the right end 11b and the left end 11c are respectively opposite to the opening edge 12b. The right end 11b combined with the opening edge 12b forms a right flange 6, and the left end 11c combined with the opening edge 12b forms a left flange 7 (see Figure 3 ). At the position of the right flange 6, a sealing member (e.g., sealing rubber) 4 is provided between the lower surface of the right end portion 11b and the surface of the opening edge portion 12b to seal the space formed therebetween. At the position of the left flange 7, a sealing member 5 having the same function as the sealing member 4 is provided.

[0023] In the following, for convenience of explanation, reference will also be made to Figure 2 The battery pack 1 shown is simplified Figure 3 . Figure 3Yes means Figure 2 The figure shows the characteristic parts of the battery pack 1. Figure 3 The positions of the right flange 6 and the left flange 7 are shown. As can be seen from the figure, the right flange 6 and the left flange 7 are located above the battery stack 3, and when the battery pack 1 is viewed from a direction parallel to the Y axis, these flanges do not appear to overlap with the battery stack 3. Figure 3 The upper surface 31 of the battery stack 3 is also shown. The upper surface 31 is located below the surface of the opening edge portion 12b in contact with the sealing members 4 and 5.

[0024] 2. Effect

[0025] Figures 4 to 6 1 is a diagram for explaining the effects of the battery pack 1 according to the embodiment. Figure 4 and Figure 5 In the figure, the Figure 3 The battery pack 1 shown is similarly simplified to the battery packs 8 and 9. The battery packs 8 and 9 are equivalent to comparative examples of the battery pack 1 according to the embodiment. The components of the battery packs 8 and 9 are similar to those of the battery packs 1 and 1. Figure 3 The difference in the configuration of the battery pack 1 shown is the position of the right and left flanges. The right and left flanges in the battery pack 8 are located at a higher position than the right and left flanges in the battery pack 1. On the other hand, the right and left flanges in the battery pack 9 are located at a lower position than the right and left flanges in the battery pack 1.

[0026] Specifically, in the battery pack 8, the upper cover 81 extends straight in a direction parallel to the Y axis, and there is no step at the end of the upper cover 81. Instead, the opening edge of the lower shell 82 moves in the positive direction of the Z axis. On the other hand, in the battery pack 9, the right end of the upper cover 91 and the opening edge of the lower shell 92, which are respectively connected to the sealing member 4, are located below the upper surface 31. The left end of the upper cover 91 and the opening edge of the lower shell 92, which are respectively connected to the sealing member 5, are also located below the upper surface 31.

[0027] exist Figure 4 , (i) shows an example of the transmission of the external force F input to the battery pack 8 in the event of a side collision. In the positive direction of the Y axis, the right flange of the battery pack 8 is located at the outermost side. Therefore, in the event of a side collision, the external force F first acts on the right flange. As a result, the mating surfaces of the opening edge of the upper cover 81 and the lower shell 82 constituting the right flange may be easily opened, and the sealing structure of the right flange cannot be maintained.

[0028] exist Figure 5 , (i) an example of the transmission of the external force F in the event of a side collision is also shown. In this example, since the right flange moves in the negative direction of the Y axis, the upper cover 91 and the lower shell 92 connected to the right flange may bite into the battery stack 3. Figure 5FIG. 1 also shows an example of the movement of gas G (e.g., combustible gas) ejected from the battery cells constituting the battery stack 3 (ii). In this example, since the gas G generated near the right flange is directly ejected to the sealing member 4, the function of the sealing member 4 may be damaged, and the gas G may leak to the outside of the battery pack 1. Figure 5 2 also shows (iii) an example of the transfer of heat H generated by the battery stack 3. In this example, the heat H is likely to accumulate between the vehicle body underbody 2 and the right and left flanges, and the battery stack 3 may need to be cooled.

[0029] In this regard, according to the battery pack 1 according to the embodiment, it is possible to reduce Figure 4 and Figure 5 The adverse conditions described in Figure 6 As shown in FIG. 1 , (i) in the event of a side collision, the step formed on the upper cover 11 resists the external force F, thereby suppressing the Figure 4 In addition, it is also possible to avoid Figure 5 Furthermore, (ii) even if the gas G is ejected at a position close to the right flange, it is possible to prevent the gas G from being ejected directly to the sealing member 4. Furthermore, (iii) the heat H generated by the battery stack 3 is easily dissipated into the atmosphere, so it is also possible to prevent Figure 5 Heat storage as described in .

Claims

1. A battery pack that houses a battery stack mounted on a vehicle, characterized in that: have: an upper cover disposed opposite to a floor of the vehicle; and The lower shell is combined with the upper cover. In the width direction of the vehicle, the opening edge of the lower shell is combined with the left end and the right end of the upper cover to form a left flange and a right flange respectively. The left flange is mounted on a left frame member of the vehicle, the left frame member is disposed on the left side of the floor, and the right flange is mounted on a right frame member of the vehicle, the right frame member is disposed on the right side of the floor. The upper surfaces of the left flange and the right flange in the width direction are located below the upper surface of the upper cover facing the floor. An upper surface of the upper cover facing the floor forms a step with upper surfaces of the left flange and the right flange.

2. The battery pack according to claim 1, characterized in that: The left flange and the right flange in the width direction are located above the battery stack.

3. The battery pack according to claim 1 or 2, characterized in that: The upper surface of the battery stack is located below the surface of the opening edge portion that faces the lower surfaces of the left end portion and the right end portion at each position of the left flange and the right flange.

4. The battery pack according to claim 3, characterized in that: A sealing member is provided between the lower surface of the left end portion and the surface of the opening edge portion opposite to the lower surface of the left end portion to seal a gap formed between these surfaces. A sealing member is provided between the lower surface of the right end portion and the surface of the opening edge portion that faces the lower surface of the right end portion and seals a gap formed between these surfaces.

Images