JP6944649B2 - Electric vehicle - Google Patents

Description

The present invention relates to an electric vehicle.

In recent years, secondary batteries such as lithium-ion secondary batteries have been used for driving portable power sources such as personal computers and mobile terminals, and electric vehicles such as electric vehicles (EV), hybrid vehicles (HV), and plug-in hybrid vehicles (PHV). It is preferably used as a power source.

In the application of a power source for driving an electric vehicle, a secondary battery generally has a battery stack in which a plurality of single batteries (battery cells) are connected and a case for accommodating the battery stack in order to increase the output. Used as a form of battery pack. For example, Patent Document 1 discloses an electric vehicle in which a battery pack having a plurality of batteries and a battery box accommodating a battery is detachably supported by a pair of left and right side frames.

Japanese Unexamined Patent Publication No. 11-180172 JP-A-2010-153117 Japanese Unexamined Patent Publication No. 10-0166889 Japanese Unexamined Patent Publication No. 2004-338558

By the way, the battery pack generally has a property that it is difficult to absorb the energy generated when the electric vehicle collides with an obstacle or the like. Therefore, for example, when the battery pack is placed under the floor, it is difficult to absorb the energy at the time of a collision against a collision from the side of the electric vehicle. Further, for example, when the battery pack is arranged at the rear part of the vehicle body, it is difficult to absorb the energy at the time of a collision against a collision from the rear of the electric vehicle. Further, since the energy generated when the electric vehicle collides with an obstacle or the like is easily input to the battery pack, the battery pack may be crushed. If the rigidity of the case is increased in order to suppress the crushing of the battery pack, the weight of the battery pack may increase and the fuel consumption may decrease. Patent Documents 2 to 4 disclose techniques related to airbags.

The present invention has been made in view of this point, and an object of the present invention is to provide an electric vehicle that easily absorbs energy generated when a vehicle collides with an obstacle or the like.

The electric vehicle according to the present invention includes a vehicle body, a battery stack in which a plurality of rechargeable and dischargeable single batteries are electrically connected and arranged in a predetermined direction, and a case for accommodating the battery stack. , The battery pack arranged on the vehicle body, the air bag provided on the battery pack and configured to be deployable, the fixing member for detachably fixing the battery pack to the vehicle body, the air bag, and the air bag. The control device includes a control device for controlling the fixing member, and the control device includes an airbag control unit that deploys the airbag to protect the battery pack when a collision with an obstacle is presumed, and an obstacle. It is provided with a fixing member control unit that separates the battery pack from the vehicle body by releasing the fixing of the battery pack when the energy due to collision with an object is estimated to be a predetermined value or more.

According to the electric vehicle according to the present invention, the fixing member control unit disconnects the battery pack from the vehicle body by releasing the fixing of the battery pack when the energy due to the collision with the obstacle is estimated to be a predetermined value or more. As a result, the space in which the battery pack is arranged can be effectively utilized as a crushable zone, and the energy transmitted to the electric vehicle can be effectively absorbed in the event of a collision with an obstacle. In addition, the airbag control unit deploys the airbag to protect the battery pack when a collision with an obstacle is suspected. As a result, the energy input to the battery pack can be reduced, and the crushing of the battery pack can be suppressed.

It is a side view which shows typically the electric vehicle which concerns on one Embodiment. It is a block diagram of the electric vehicle which concerns on one Embodiment. It is a side view which shows typically the state which the battery pack is fixed with respect to a vehicle body. It is a side view which shows typically the state which the airbag is deployed. It is a side view which shows typically the state which the battery pack is separated from the vehicle body. It is a flowchart which showed the procedure of operation of an electric vehicle when a collision with an obstacle is estimated.

Hereinafter, preferred embodiments of the present invention will be described. Matters other than those specifically mentioned in the present specification and necessary for carrying out the present invention can be grasped as design matters of those skilled in the art based on the prior art in the art. The present invention can be carried out based on the contents disclosed in the present specification and common general technical knowledge in the art. It should be noted that each drawing is drawn schematically and does not necessarily reflect the actual product. In addition, each drawing shows only one example, and each drawing does not limit the present invention unless otherwise specified.

As shown in FIG. 1, the electric vehicle 10 includes a vehicle body 20, a battery pack 30, an airbag 40, a fixing member 50, and a control device 60 (see FIG. 2). The symbols F, Rr, U, and D in the drawings mean front, back, top, and bottom, respectively. However, the above-mentioned direction is merely a direction determined for convenience of explanation, and does not limit the installation mode of the battery pack 30 or the like, and does not limit the present invention at all.

As shown in FIG. 1, the battery pack 30 is arranged under the rear seat of the vehicle body 20 and fixed to the floor panel 22 (see FIG. 3A). The battery pack 30 is arranged so as to close the opening 24 (see FIG. 3A) formed in the floor panel 22. The battery pack 30 is arranged outside the vehicle interior. The battery pack 30 may be arranged at a position other than the lower side of the rear seat.

As shown in FIG. 2, the battery pack 30 includes a battery stack 32 and a case 33. The battery stack 32 includes a plurality of cell cells (not shown). The cells have, for example, square outer shapes, and are arranged in a row in the left-right direction in FIG. 1 so that a pair of flat surfaces face each other. The cells are electrically connected in series with each other by a bus bar. The cell is integrally held by a restraint band or the like. However, the shape, number, arrangement, etc. of the cells may be changed as appropriate. The cell is typically a rechargeable or dischargeable secondary battery, such as a lithium ion secondary battery. The cell is typically provided with a positive electrode, a negative electrode, an electrolytic solution, and a cell case for accommodating them. The electrolytic solution contains, for example, a non-aqueous solvent such as carbonates and a supporting salt such as a lithium salt. Further, the cell may be an all-solid-state battery (for example, an all-solid-state lithium secondary battery), a fuel cell, a nickel hydrogen battery, or another secondary battery. The charge / discharge control of the cell is performed by the control device 60.

The case 33 is a housing for accommodating the battery stack 32. The material of the case 33 is, for example, metal or resin. The shape and size of the case 33 may be appropriately changed according to, for example, the size and number of battery stacks 32.

The airbag 40 is provided in the battery pack 30. In this embodiment, the airbag 40 is provided on the lower surface of the battery pack 30. The airbag 40 may be provided on the upper surface or the side surface of the battery pack 30. The airbag 40 is configured to be deployable. The airbag 40 is connected to a gas suction device (not shown) that sucks gas into the airbag 40. As shown in FIG. 3B, when gas is sucked into the airbag 40 from the gas suction device, the airbag 40 is deployed and covers the battery pack 30. The airbag 40 covers, for example, the lower surface and the side surface of the battery pack 30. That is, the airbag 40 has a function of protecting the battery pack 30. The airbag 40 is controlled by the control device 60. That is, the control device 60 controls the deployment of the airbag 40 by controlling the gas suction device. In the present embodiment, since the airbag 40 is provided outside the vehicle interior, a protective member for protecting the airbag 40 from mud, stones, or the like may be provided on the surface of the airbag 40.

The fixing member 50 is configured to detachably fix the battery pack 30 to the vehicle body 20. As shown in FIG. 3A, in the present embodiment, the fixing member 50 includes a first fixing member 51 for fixing the front side of the battery pack 30, and a second fixing member 52 for fixing the rear side of the battery pack 30. ing. The first fixing member 51 and the second fixing member 52 are provided on the floor panel 22. The first fixing member 51 and the second fixing member 52 are, for example, solenoids, and include a plunger 54 and a case body 55 having a coil (not shown) inside. The plunger 54 is configured to be engageable with an engaging hole (not shown) formed in the battery pack 30. Normally, since the plunger 54 is engaged with the engaging hole, the battery pack 30 is fixed to the vehicle body 20. On the other hand, as shown in FIG. 3C, when the power of the first fixing member 51 and the second fixing member 52 is turned on, the plunger 54 moves in the direction away from the battery pack 30. That is, at least a part of the plunger 54 is pulled into the case body 55. As a result, the engagement between the plunger 54 and the engagement hole formed in the battery pack 30 is released, and the battery pack 30 is separated from the vehicle body 20. That is, the battery pack 30 falls from the vehicle body 20 together with the airbag 40 as shown by the arrow X in FIG. 3C. The first fixing member 51 and the second fixing member 52 are controlled by the control device 60. That is, the power ON and OFF of the first fixing member 51 and the second fixing member 52 are controlled by the control device 60. The fixing member 50 is not limited to the solenoid. Examples of the fixing member 50 include an electrically controllable mechanism such as an electromagnetic lock mechanism.

As shown in FIG. 2, the electric vehicle 10 includes a front side camera 26 and a rear side camera 28. Images (moving images) taken by the front side camera 26 and the rear side camera 28 are always transmitted to the control device 60. The electric vehicle 10 may further include various sensors capable of detecting a collision with an obstacle. The sensor is located in front of or behind the electric vehicle 10, for example, by emitting ultrasonic waves, radio waves, laser light, or the like in front of and behind the electric vehicle 10 and receiving the reflected wave or reflected light. Examples include those capable of detecting the distance, size, moving speed, etc. of an obstacle.

The control device 60 includes a central processing unit (CPU) that executes instructions of a control program, a ROM that stores a program executed by the CPU, a RAM that is used as a working area for developing the program, and the above program and various data. It is equipped with a storage device such as a memory for storing the data. As shown in FIG. 2, the control device 60 includes a collision estimation unit 62, an airbag control unit 64, a load input estimation unit 66, a determination unit 68, and a fixing member control unit 70. Each of these parts is realized by a program. This program can be downloaded via the internet. Further, each of these parts may be feasible by a processor and / or a circuit or the like. The specific control of each part described above will be described later.

Next, the procedure for operating the electric vehicle 10 when a collision with an obstacle is presumed will be described. FIG. 4 is a flowchart according to an embodiment. The estimation of the collision with the obstacle is performed when the electric vehicle 10 is driven (that is, when the electric vehicle 10 is capable of traveling, including when the electric vehicle 10 is stopped and when the electric vehicle 10 is traveling).

First, in step S10, the collision estimation unit 62 estimates whether the electric vehicle 10 may collide with an obstacle. The collision estimation unit 62 performs image analysis on the images transmitted from the front side camera 26 and the rear side camera 28. As a result, the collision estimation unit 62 calculates the distance, size, moving speed, etc. of the obstacle located in front of or behind the electric vehicle 10. If it is estimated that the electric vehicle 10 collides with an obstacle as a result of the image analysis, the process proceeds to step S20. On the other hand, if it is not estimated that the electric vehicle 10 collides with an obstacle as a result of the image analysis, step S10 is repeatedly executed until the electric vehicle 10 is driven (that is, until it stops). Since a conventionally known method can be adopted as the method for performing image analysis, the description here will be omitted.

When a collision between the electric vehicle 10 and an obstacle is estimated by the collision estimation unit 62, the airbag control unit 64 deploys the airbag 40 in step S20. That is, the airbag control unit 64 sucks gas into the airbag 40 and deploys the airbag 40 by controlling the gas suction device (not shown). As a result, the battery pack 30 is protected by the airbag 40.

Next, in step S30, the load input estimation unit 66 performs image analysis on the images transmitted from the front side camera 26 and the rear side camera 28. The load input estimation unit 66 calculates, for example, the moving speed of an obstacle per frame (one frame), and estimates the energy F due to the collision with the obstacle from the assumed weight of the obstacle. Then, the determination unit 68 compares the energy F estimated by the load input estimation unit 66 with the allowable impact load P that the airbag 40 can withstand. If the determination unit 68 determines that the energy F is equal to or greater than the allowable impact load P, the process proceeds to step S40. On the other hand, when the determination unit 68 determines that the energy F is smaller than the allowable impact load P, the impact applied to the battery pack 30 by the airbag 40 can be sufficiently alleviated, so that the battery pack 30 can be fixed. It will not be released. The allowable impact load P is calculated by performing a predetermined strength test (for example, creep withstand voltage test, repeated compression test, etc.) in advance, and is stored in the control device 60.

When the determination unit 68 determines that the energy F is equal to or greater than the allowable impact load P, the fixing member control unit 70 controls the first fixing member 51 and the second fixing member 52 with respect to the vehicle body 20 of the battery pack 30. Release the lock. As a result, the battery pack 30 is separated from the vehicle body 20. Here, when the battery pack 30 is separated from the vehicle body 20, a space for the battery pack 30 to exist is formed inside the vehicle body 20. Since such a space functions as a crushable zone, the energy F transmitted to the electric vehicle 10 can be effectively absorbed in the event of a collision with an obstacle.

As described above, according to the electric vehicle 10 according to the present embodiment, the fixing member control unit 70 fixes the battery pack 30 when the energy F due to the collision with the obstacle is estimated to be equal to or more than the allowable impact load P. The battery pack 30 is separated from the vehicle body 20 by releasing. As a result, the space in which the battery pack 30 is arranged can be effectively utilized as a crushable zone, and the energy transmitted to the electric vehicle 10 can be effectively absorbed in the event of a collision with an obstacle. Further, the airbag control unit 64 deploys the airbag 40 to protect the battery pack 30 when a collision with an obstacle is presumed. As a result, the energy input to the battery pack 30 can be reduced, and the crushing of the battery pack 30 can be suppressed.

Although various electric vehicles proposed herein have been described above, the embodiments mentioned here do not limit the present invention unless otherwise specified.

In the above-described embodiment, the first fixing member 51 and the second fixing member 52 are arranged on the front side and the rear side of the battery pack 30, but are not limited thereto. The first fixing member 51 and the second fixing member 52 may be arranged on the side of the battery pack 30, that is, on the left side and the right side.

In the above-described embodiment, the battery pack 30 is arranged outside the vehicle interior, but a part of the battery pack 30 may be arranged inside the vehicle interior.

10 Electric vehicle 20 Body 30 Battery pack 32 Battery stack 33 Case 40 Airbag 50 Fixing member 51 First fixing member 52 Second fixing member 60 Control device 64 Airbag control unit 70 Airbag control unit 70 Fixing member control unit

Claims (1)

With the car body
A battery pack arranged on the vehicle body, which includes a battery stack in which a plurality of rechargeable and dischargeable single batteries are electrically connected and arranged in a predetermined direction, and a case for accommodating the battery stack.
An airbag provided in the battery pack and configured to be deployable,
A fixing member that detachably fixes the battery pack to the vehicle body,
A control device for controlling the airbag and the fixing member is provided.
The control device is
An airbag control unit that deploys the airbag to protect the battery pack when a collision with an obstacle is suspected.
If the energy due to the collision with the obstacle is estimated to more than a predetermined value, and wherein the fixing member control unit for dropping from the vehicle body and disconnect the battery pack from the vehicle body by releasing the fixation of the battery pack , Equipped with an electric vehicle.

Images