JP7652201B2 - Power storage device - Google Patents

Description

This disclosure relates to an electricity storage device.

As a conventional power storage device, JP 2018-072296 A (Patent Document 1) discloses a configuration in which an impact detection device is attached to the underside of a battery pack tray.

JP 2018-072296 A

In Patent Document 1, when the impact detection device (sensor) detects an impact, pressure is also applied to the bottom surface of the battery pack tray. If the battery pack tray is deformed by this pressure, there is a risk that the bottom surface of the battery pack (electricity storage stack) will be damaged.

The present disclosure has been made in consideration of the above problems, and its purpose is to provide an electricity storage device that can reduce damage to the electricity storage stack even if an impact is applied to the protective panel (also called a "share panel") at the bottom of the vehicle due to road surface interference, etc.

The energy storage device according to the present disclosure includes an energy storage stack including a plurality of energy storage cells arranged in a predetermined direction; a restraining member that presses the energy storage stack in a predetermined direction to restrain the energy storage stack; a storage case having a bottom wall portion and containing the restrained energy storage stack by placing the energy storage stack restrained by the restraining member on the bottom wall portion; a cooler that is provided on the opposite side of the bottom wall portion from the restrained energy storage stack and cools the energy storage stack; a protective panel that is located below the cooler in a top view of the energy storage device and protects the cooler from interference with the road surface or obstacles on the road surface; and a sensor that is installed between the protective panel and the bottom wall portion and detects pressure in a vertically upward direction. The restraining member extends in a predetermined direction between the energy storage stack and the bottom wall portion. The sensor is located below the restraining member in a top view of the energy storage device.

According to the above configuration, when the protective panel is deformed and collides with the sensor, the impact force applied to the sensor is transmitted to the power storage stack via the restraining member. Therefore, the impact force applied to the power storage stack can be reduced compared to a configuration in which the impact force applied to the sensor is transmitted to the power storage stack without passing through the restraining member. Therefore, even if an impact is applied to the protective panel due to interference with the road surface or an obstacle on the road surface, damage to the power storage stack can be reduced. Furthermore, according to the above configuration, the detection result of the sensor enables the user to know that the protective panel has been deformed and that there is a possibility of damage to the power storage device.

Preferably, the cooler has an opening extending in a predetermined direction. The opening is located below the restraining member when viewed from above the power storage device. A sensor is installed in the opening. With the above configuration, it is possible to prevent an impact applied to the sensor from being transmitted to the cooler.

According to the present disclosure, even if an impact is applied to the protective panel due to interference with the road surface or an obstacle on the road surface, damage to the energy storage stack can be reduced.

FIG. 2 is a cross-sectional view taken along line II-II of FIG. 1. 10 is a cross-sectional view illustrating a state in which a share panel is deformed due to interference between a vehicle equipped with an electricity storage device and a road surface or an obstacle on the road surface. FIG.

Below, an embodiment of the present disclosure will be described with reference to the drawings. In the following description, the same components are given the same reference numerals. Their names and functions are also the same. Therefore, detailed descriptions thereof will not be repeated.

Figure 1 is an exploded perspective view of a power storage device according to this embodiment. The power storage device 100 according to this embodiment will be described with reference to Figure 1.

The energy storage device 100 is installed in a hybrid vehicle that can run using at least one of the power sources of a motor and an engine, or in an electric vehicle that runs using driving force obtained from electrical energy.

The energy storage device 100 includes a plurality of energy storage stacks 10, a storage case 20, a cooler 30, an adhesive layer 40 (see FIG. 2), a shear panel (protective panel) 50, and a plurality of restraining members 70. The storage case 20 includes an upper case 21 and a lower case 22.

Each of the multiple energy storage stacks 10 includes multiple energy storage cells 11 arranged side by side in an arrangement direction DR1. When the energy storage device 100 is mounted on a vehicle, the arrangement direction DR1 is, for example, approximately parallel to the left-right direction of the vehicle. Spacers (not shown) are arranged between adjacent energy storage cells 11.

The multiple storage stacks 10 are arranged side by side in a cross direction DR2 (more specifically, a direction perpendicular to the arrangement direction) that crosses the arrangement direction DR1. In the mounted state, the cross direction DR2 is, for example, approximately parallel to the front-rear direction of the vehicle.

Each of the multiple storage stacks 10 is fixed to the housing case 20 (more specifically, the bottom wall portion 23 described below) by an adhesive layer 40 (see FIG. 2). Each storage stack 10 may also be fixed to the housing case 20 by a bracket.

The storage cell 11 is, for example, a secondary battery such as a nickel-metal hydride battery or a lithium-ion battery. The single cell has, for example, a rectangular shape. The secondary battery may use a liquid electrolyte or a solid electrolyte. The storage cell may also be a unit capacitor configured to store electricity.

Each of the multiple restraining members 70 presses a different one of the storage stacks 10 in the arrangement direction DR1 to restrain the storage stacks 10. Each restraining member 70 extends in the arrangement direction DR1 between the storage stack 10 and the lower case 22 (more specifically, the bottom wall portion 23 described later).

The storage case 20 accommodates multiple power storage stacks 10 inside. The upper case 21 has a generally box-like shape that opens downward. The lower case 22 includes a bottom wall portion 23 and has a generally box-like shape that opens upward. The storage case 20 accommodates the restrained power storage stack 10 by placing the restrained power storage stack 10 on the bottom wall portion 23, which is restrained by the restraining member 70.

The bottom wall portion 23 includes, for example, a mounting portion 24, a pair of bottom wall portions 25, and a pair of connection portions 26. The mounting portion 24 has a mounting surface 24a on which the energy storage stack 10 is placed. The bottom wall portion 23 is provided such that the mounting portion 24 is located at a position generally higher than the bottom wall portions 25.

The mounting surface 24a is divided into a plurality of regions in the intersecting direction by the partitioning member 27. The power storage stack 10 is disposed in each of the plurality of partitioned regions R1 divided by the partitioning member 27. More specifically, in each partitioned region R1, the mounting surface 24a has a first portion 241, a second portion 242, and a recess 243.

One side of the power storage stack 10 in the intersecting direction DR2 is placed on the first portion 241. The other side of the power storage stack 10 in the intersecting direction DR2 is placed on the second portion 242. The recess 243 is provided between the first portion 241 and the second portion 242. The recess 243 is provided so as to be continuous from one end to the other end of the mounting surface 24a in the arrangement direction DR1. In addition, in each partition region R1, a bottom wall portion 25 is provided so as to surround the mounting surface 24a when viewed from above.

A pair of bottom wall portions 25 are provided at both ends of the bottom wall portion 23 in the arrangement direction DR1. The bottom wall portions 25 extend along the direction in which the plurality of power storage stacks 10 are arranged (cross direction DR2). The bottom wall portions 25 are located at a height lower than the placement surface 24a. The height direction is parallel to the direction in which the upper case 21 and the lower case 22 are arranged, and corresponds to the up-down direction.

The pair of connecting portions 26 connect the pair of bottom wall portions 25 and the mounting portion 24. The pair of connecting portions 26 are curved so that their height position decreases toward the outside in the arrangement direction DR1.

The cooler 30 is a device for cooling multiple power storage stacks 10. The cooler 30 is disposed outside the storage case 20. Specifically, the cooler 30 is disposed below the bottom wall portion 23 of the lower case 22. More specifically, the cooler 30 is provided on the opposite side of the bottom wall portion 23 to the restrained power storage stack 10, and cools the power storage stack 10. The cooler 30 is located between the bottom wall portion 23 and the share panel 50.

The cooler 30 is made of a metal material such as aluminum. The cooler 30 includes a plurality of cooling sections 32 and a holding frame 34. The plurality of cooling sections 32 are provided to correspond to the first portion 241 and the second portion 242 in each partition region R1. The plurality of cooling sections 32 are in thermal contact with the back surface 24b of the portion located opposite the first portion 241 and the second portion 242 via a thermally conductive layer 60 (see FIG. 2).

The cooling sections 32 are arranged in a line in a direction parallel to the intersecting direction DR2. Each of the cooling sections 32 is arranged in a position facing the power storage stack 10 across the bottom wall section 23. The cooling sections 32 are arranged so as to be in thermal contact with the back surface 24b (see FIG. 2) of the mounting section 24 located on the opposite side to the side on which the mounting surface 24a is located. This allows the cooling sections 32 to efficiently cool the mounting section 24, and therefore the power storage stack 10 placed on the mounting surface 24a.

The cooling section 32 is provided with a cooling flow path 32a (see FIG. 2) through which a cooling medium (such as water) flows to cool the power storage stack 10.

The holding frame 34 holds each cooling section 32. The holding frame 34 is formed in a ring shape that surrounds the multiple cooling sections 32. In this embodiment, the holding frame 34 is formed in a substantially rectangular shape. Each cooling section 32 is connected to the holding frame 34 at both ends in the arrangement direction DR1.

The share panel 50 is arranged to cover the cooler 30 from below. The share panel 50 protects the cooler 30. More specifically, the share panel 50 is located below the cooler 30 when viewed from above the energy storage device 100, and protects the cooler 30 from interference with the road surface or obstacles on the road surface. The share panel 50 is made of a metal material.

Figure 2 is a cross-sectional view taken along line II-II in Figure 1. As shown in Figure 2, the bottom wall portion 23 (specifically, the mounting portion 24) includes a bottom wall portion 2410 having a first portion 241, a bottom wall portion 2420 having a second portion 242, and a bottom wall portion 2430 that is continuous with the two bottom wall portions 2410, 2420 and protrudes from the bottom wall portions 2410, 2420 toward the share panel 50. The bottom wall portion 2430 has a recess 243.

The restraining member 70 extends in the arrangement direction DR1 (see FIG. 1) between the power storage stack 10 and the bottom wall portion 23. The restraining member 70 is located between the power storage stack 10 and the bottom wall portion 2430. In this example, the restraining member 70 is located on the recess 243 of the mounting portion 24.

The energy storage device 100 further includes a piezoelectric sensor 80 that detects pressure. The piezoelectric sensor 80 is installed between the share panel 50 and the bottom wall portion 23, and detects pressure in the vertically upward direction. The piezoelectric sensor 80 is located below the restraining member 70 when viewed from above the energy storage device 100. In this example, the piezoelectric sensor 80 is attached to the surface of the bottom wall portion 2430 opposite the recess 243 (a part of the back surface 24b).

The cooler 30 has an opening 39 extending in the arrangement direction DR1. The opening 39 is located below the restraining member 70 when viewed from above the energy storage device 100. A piezoelectric sensor 80 is installed within the opening 39. The cooler 30 has flange portions 321, 322 facing each other. The flange portions 321, 322 extend parallel to the bottom wall portion 23. The piezoelectric sensor 80 is installed between the flange portions 321 and 322.

Figure 3 is a cross-sectional view showing a state in which the share panel 50 is deformed due to interference between a vehicle equipped with the energy storage device 100 and the road surface or an obstacle on the road surface. Note that Figure 3 is a cross-sectional view taken at the same position as Figure 2.

As shown in FIG. 3, in this example, the shear panel 50 deforms in the direction of arrow A (upward), causing the shear panel 50 to collide with the piezoelectric sensor 80. When the shear panel 50 collides with the piezoelectric sensor 80, the piezoelectric sensor 80 transmits an impact force to the equipment located above the piezoelectric sensor 80. In this example, the restraining member 70 is located above the piezoelectric sensor 80.

As a result, the impact force applied to the piezoelectric sensor 80 is transmitted to the power storage stack 10 via the restraining member 70. This reduces the impact force applied to the power storage stack 10 compared to a configuration in which the impact force applied to the piezoelectric sensor 80 is transmitted to the power storage stack 10 without passing through the restraining member 70. Therefore, according to the power storage device 100, even if an impact is applied to the share panel 50 due to road surface interference, etc., damage to the power storage stack 10 can be reduced.

Furthermore, the piezoelectric sensor 80 can detect deformation of the share panel 50. The vehicle controller (not shown) displays the detection result on a monitor or the like inside the vehicle, allowing the user or the like to know that the share panel 50 has been deformed and that there is a possibility of damage to the energy storage device 100.

As described above, the cooler 30 has an opening 39 extending in the arrangement direction DR1. The opening 39 is located below the restraining member 70 when viewed from above the energy storage device 100. The piezoelectric sensor 80 is installed within the opening 39. This configuration can prevent an impact applied to the piezoelectric sensor 80 from being transmitted to the cooler 30.

In particular, by positioning the piezoelectric sensor 80 in the vertical direction so that it is more susceptible to impacts caused by deformation of the share panel 50 than the cooler 30, the cooler 30 can be protected from interference with the road surface or obstacles on the road surface.

The embodiments disclosed herein should be considered to be illustrative and not restrictive in all respects. The scope of the present disclosure is defined by the claims, and is intended to include all modifications within the meaning and scope of the claims.

10 storage stack, 11 storage cell, 20 storage case, 21 upper case, 22 lower case, 23, 2410, 2420, 2430 bottom wall, 24 placement portion, 24a placement surface, 24b back surface, 25 bottom wall, 26 connection portion, 27 partition member, 30 cooler, 32 cooling portion, 32a cooling flow path, 34 holding frame portion, 39 opening, 40 adhesive layer, 50 shear panel, 60 thermal conduction layer, 70 restraining member, 80 piezoelectric sensor, 100 storage device, 241 first portion, 242 second portion, 243 recess, 321, 322 flange portion, DR1 arrangement direction, DR2 cross direction, R1 partition area.

Claims (2)

A power storage device,
A storage stack including a plurality of storage cells arranged in a predetermined direction;
a restraining member that presses the electricity storage stack in the predetermined direction to restrain the electricity storage stack;
a storage case having a bottom wall portion, the storage stack being restrained by the restraining member being placed on the bottom wall portion to accommodate the restrained storage stack;
a cooler that is provided on an opposite side of the bottom wall portion from the restrained electricity storage stack and that cools the electricity storage stack;
a protective panel that is located below the cooler when viewed from above the power storage device and protects the cooler from interference with a road surface or an obstacle on the road surface;
a sensor that is installed between the protection panel and the bottom wall portion and detects a pressure in a vertical upward direction;
the restraint member extends in the predetermined direction between the power storage stack and the bottom wall portion,
The sensor is located below the restraining member in a top view of the power storage device. The cooler has an opening formed therein and extending in the predetermined direction,
the opening is located below the restraining member in a top view of the power storage device,
The power storage device according to claim 1 , wherein the sensor is disposed inside the opening.

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