JP7652202B2 - Power storage device - Google Patents

Description

This disclosure relates to an electricity storage device.

As a conventional vehicle collision detection device, JP 2019-006239 A (Patent Document 1) discloses a vehicle collision detection device that uses a piezoelectric film divided into a grid pattern to separately detect non-contact events such as road surface interference where the bumper comes into contact with an obstacle on the road, and contact events such as a collision with a bicycle. In more detail, the piezoelectric film is provided on the back side of the bumper cover.

JP 2019-006239 A

When detecting an impact using a piezoelectric film as in Patent Document 1, there is a risk that the impact may not be detected if it occurs only for a moment.

The present disclosure has been made in consideration of the above problems, and its purpose is to provide an energy storage device that can detect an impact even if an impact is applied momentarily to the bottom of a vehicle equipped with an energy storage cell due to interference with the road surface or an obstacle on the road surface.

The energy storage device according to the present disclosure includes an energy storage stack including a plurality of energy storage cells, a housing case having a bottom wall portion and housing the energy storage stack by installing the energy storage stack on the bottom wall portion, a cooler provided on the opposite side of the bottom wall portion from the energy storage stack and cooling the energy storage stack, a protective panel located below the cooler in a top view of the energy storage device and protecting the cooler from interference with the road surface or obstacles on the road surface, a sensor provided between the protective panel and the bottom wall portion and having a switch that is turned on when pressure is applied in a vertically upward direction, and a pressurized portion provided between the protective panel and the sensor and plastically deformed when pressed by the protective panel based on deformation of the protective panel toward the bottom wall portion. When plastically deformed, the pressurized portion applies pressure in a vertically upward direction to the switch.

With this configuration, when the pressure-receiving portion undergoes plastic deformation, it applies pressure to the switch in a vertically upward direction, turning the switch on. Once the switch is on, the pressure-receiving portion does not return to its original shape, so the switch continues to remain on. In this way, in the energy storage device, even if only a momentary impact is applied to the protective panel, the pressure-receiving portion undergoes plastic deformation, allowing the switch to remain on. In other words, even if the impact is only momentary, the sensor can detect the impact.

Preferably, the energy storage device further includes a cooler between the pressurized portion and the protective panel. The cooler includes first and second flange portions each extending in a predetermined direction and facing each other. The sensor is located between the first flange portion and the second flange portion when viewed from above the energy storage device. The energy storage device has a pressurized portion and further includes a cover that covers the sensor from the protective panel side.

With this configuration, the switch can be turned on by the protective panel colliding with the cover.

Preferably, the energy storage device further includes a cooler between the bottom wall and the protective panel. The cooler has a flange extending in a predetermined direction as a pressurized portion. The sensor is installed between the flange and the bottom wall when viewed from above the energy storage device.

With this configuration, the flange portion undergoes plastic deformation, allowing the sensor switch to remain in the on state.

According to this disclosure, it is possible to detect an impact even if the impact is only momentarily applied to the bottom of a vehicle equipped with a storage cell.

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 a vehicle equipped with an electricity storage device interfering with a road surface or an obstacle on the road surface. FIG. FIG. 11 is a cross-sectional view of a power storage device according to another embodiment. FIG. 5 is an enlarged view of a main portion of FIG. 4 . 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.

Each embodiment of the present disclosure will be described below 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.

[First embodiment]
Fig. 1 is an exploded perspective view of a power storage device according to the present embodiment. With reference to Fig. 1, a power storage device 100 according to the present embodiment will be described.

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 sensor 80 and a cover 90. The sensor 80 is installed between the share panel 50 and the bottom wall portion 23. The sensor 80 is located below the restraining member 70 when viewed from above the energy storage device 100. The sensor 80 has a switch 81. The switch 81 is turned on when pressure is applied in a vertically upward direction.

In this example, the switch 81 is a movable element such as a push button. When an external force is applied to the switch 81, the switch 81 moves vertically upward. This causes the sensor 80 to detect the force applied in the vertically upward direction. The detection result by the sensor 80 is sent to the vehicle controller (not shown).

The cover 90 covers the sensor 80 from the share panel 50 side. The cover 90 has side walls 91 and 92 and a bottom wall (pressurized portion) 93. The side walls 91 and 92 face each other with the sensor 80 in between.

The bottom wall portion 93 is provided between the share panel 50 and the sensor 80. The bottom wall portion 93 faces the switch 81. As described in detail below, the bottom wall portion 93 is pressed by the share panel 50 and plastically deforms based on the deformation of the share panel 50 toward the bottom wall portion 23.

In this example, the bottom wall portion 93 and the switch 81 are spaced apart. The bottom wall portion 93 and the switch 81 are close to each other. This is not limited to the above, and the bottom wall portion 93 may be in contact with the switch 81 as long as the switch 81 is in the off state.

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 cover 90 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 sensor 80 and the cover 90 are 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.

When an instantaneous impact is applied to the share panel 50, as shown in FIG. 3, in this example, the share panel 50 deforms in the direction of arrow A (upward) due to road surface interference, etc., and the share panel 50 collides with the bottom wall portion 93 of the cover 90. As the share panel 50 deforms toward the bottom wall portion 23, the bottom wall portion 93 is pressed by the share panel 50 and plastically deforms. When the bottom wall portion 93 plastically deforms, it applies pressure in a vertically upward direction to the switch 81. Note that in this example, when the bottom wall portion 93 plastically deforms, the side wall portions 91 and 92 also plastically deform.

When the bottom wall portion 93 is plastically deformed and the switch 81 is turned on, the bottom wall portion 93 does not return to its original shape, and the switch 81 continues to maintain the on state. In this way, in the energy storage device 100, even if only a momentary impact is applied to the share panel 50, the bottom wall portion 93 is plastically deformed, so that the switch 81 can continue to be in the on state. In other words, even if the impact is applied only for an instant, the sensor 80 can detect the impact.

As described above, the energy storage device 100 includes a restraining member 70 that presses the energy storage stack 10 in the arrangement direction DR1 to restrain the energy storage stack 10. The restraining member 70 extends in the arrangement direction DR1 between the energy storage stack 10 and the bottom wall portion 23. The sensor 80 is located below the restraining member 70 when viewed from above the energy storage device 100.

As a result, the impact force applied to the bottom wall portion 23 (more specifically, the bottom wall portion 2430) is transmitted to the power storage stack 10 via the restraining member 70. Therefore, the impact force applied to the power storage stack 10 can be reduced compared to a configuration in which the impact force applied to the bottom wall portion 2430 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, as described above, the cover 90 has a bottom wall portion 93 and covers the sensor 80 from the side of the shared panel 50. With this configuration, the switch 81 can be turned on when the shared panel 50 collides with the cover 90.

[Embodiment 2]
In the first embodiment, a configuration has been described in which power storage device 100 includes cover 90 that covers sensor 80, and sensor 80 is installed between flange portion 321 and flange portion 322. In particular, in the first embodiment, a configuration has been described in which at least bottom wall portion 93 of cover 90 is plastically deformed to maintain switch 81 in an on state.

In this embodiment, a configuration is described in which the switch 81 is turned on by plastic deformation of the flange portions 321 and 322 of the cooler 30. In other words, a configuration is described in which the flange portions 321 and 322 are used as pressure-receiving portions that undergo plastic deformation.

Figure 4 is a cross-sectional view of the energy storage device 100A. Note that Figure 4 is a cross-sectional view at the same position as Figure 2 of the first embodiment. As shown in Figure 4, the energy storage device 100A has two sensors 80A and 80B instead of the sensor 80. Unlike the energy storage device 100 of the first embodiment, the energy storage device 100A does not have a cover 90.

Sensors 80A and 80B have a switch 81, similar to sensor 80. Sensors 80A and 80B have the same function as sensor 80. Sensors 80A and 80B detect forces applied in the vertical upward direction.

Sensors 80A and 80B, like sensor 80, are installed between the share panel 50 and the bottom wall portion 23. Sensors 80A and 80B are installed on the back surface 24b side of the bottom wall portion 23. In this example, sensors 80A and 80B are installed below the bottom wall portion 2430.

In more detail, the sensor 80A is installed between the flange portion (pressurized portion) 321 of the cooler 30 and the bottom wall portion 23 when viewed from above the energy storage device 100A. The switch 81 of the sensor 80A faces the flange portion 321. The sensor 80B is located between the flange portion (pressurized portion) 322 of the cooler 30 and the bottom wall portion 23 when viewed from above the energy storage device 100A. The switch 81 of the sensor 80B faces the flange portion 322.

In this example, the flange portion 321 is provided between the share panel 50 and the sensor 80A. The flange portion 322 is provided between the share panel 50 and the sensor 80B. Details will be described later, but the flange portions 321 and 322 are pressed by the share panel 50 and plastically deformed based on the deformation of the share panel 50 toward the bottom wall portion 23.

Figure 5 is an enlarged view of the main parts of Figure 4. Figure 6 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 100A and the road surface or an obstacle on the road surface. Figure 6 is also an enlarged view of the main parts, which show the same main parts as Figure 5.

As shown in Figures 5 and 6, assume that the flange portion 321 transitions from the state shown in Figure 5 to the state shown in Figure 6 due to the deformation of the shear panel 50. In more detail, since the cooler 30 is made of a metal material as described above, the cooler 30 undergoes plastic deformation at the flange portion 321.

In this case, the flange portion 321 applies pressure in a vertically upward direction to the switch 81 of the sensor 80A. As a result, the switch 81 of the sensor 80A turns on. Once the flange portion 321 is plastically deformed and the switch 81 turns on, the flange portion 321 does not return to its original shape, and the switch 81 continues to maintain the on state. In this way, in the energy storage device 100, even if only a momentary impact is applied to the share panel 50, the flange portion 321 plastically deforms, allowing the switch 81 of the sensor 80A to continue to be in the on state.

When the flange portion 322 is plastically deformed due to the deformation of the shear panel 50, the flange portion 322 applies pressure in a vertically upward direction to the switch 81 of the sensor 80B. As a result, the switch 81 of the sensor 80B is turned on. Therefore, the plastic deformation of the flange portion 322 allows the switch 81 of the sensor 80B to be kept in the on state.

In this manner, in this embodiment as well, as in embodiment 1, even if the impact is only momentary, the impact can be detected by sensors 80A and 80B.

The configuration of embodiment 1 and the configuration of embodiment 2 may be combined. That is, the power storage device may be configured to include sensor 80 and sensors 80A and 80B.

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 Electricity storage stack, 11 Electricity storage cell, 20 Storage case, 21 Upper case, 22 Lower case, 23, 93, 2410, 2420, 2430 Bottom wall portion, 24 Placement portion, 24a Placement surface, 24b Back surface, 25 Bottom wall portion, 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 Restraint member, 80, 80A, 80B Sensor, 81 Switch, 90 Cover, 91, 92 Side wall portion, 100, 100A Electricity storage device, 241 First portion, 242 Second portion, 243 Recess, 321, 322 Flange portion, DR1 Arrangement direction, DR2 Intersecting direction, R1 Partition area.

Claims (3)

A power storage device,
A storage stack including a plurality of storage cells;
a housing case having a bottom wall portion and housing the power storage stack by placing the power storage stack on the bottom wall portion;
a cooler that is provided on an opposite side of the bottom wall portion from the 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 has a switch that is turned on when pressure is applied in a vertically upward direction;
a pressure-receiving portion that is provided between the protection panel and the sensor and that is pressed by the protection panel and plastically deformed based on the protection panel being deformed toward the bottom wall portion,
When the pressure-receiving portion undergoes the plastic deformation, the pressure is applied to the switch in the vertically upward direction. A cooler is further provided between the bottom wall portion and the protective panel,
the cooler includes first and second flange portions each extending in the predetermined direction and facing each other;
the sensor is located between the first flange portion and the second flange portion in a top view of the power storage device,
The power storage device according to claim 1 , further comprising a cover having the pressure-receiving portion and covering the sensor from a side of the protection panel. A cooler is further provided between the bottom wall portion and the protective panel,
The cooler has a flange portion extending in the predetermined direction as the pressurized portion,
The power storage device according to claim 1 , wherein the sensor is disposed between the flange portion and the bottom wall portion in a top view of the power storage device.

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