JP6864255B2 - Electric vehicle battery pack - Google Patents

Description

The present invention relates to a battery pack mounted on a lower portion of an electric vehicle, and more particularly to a battery pack of an electric vehicle having improved workability for replacing the battery pack.

Many electric vehicles such as electric vehicles are equipped with a battery pack that serves as a driving power source under the floor of the vehicle body (lower part of the vehicle). Many battery packs placed under the floor contain a large number of rechargeable batteries in a flat battery case (for example, composed of a tray-cover joint). Then, a power supply circuit that generates a predetermined power supply voltage is configured from the connection of each battery. That is, the electric power generated by the battery is supplied to the motor and other devices that are the drive source of the electric vehicle.

Conventionally, as disclosed in Reference 1, such a battery pack has used a structure in which a large number of batteries in a battery case are directly connected in series or in parallel to secure a required voltage.

Japanese Unexamined Patent Publication No. 2003-257390

By the way, in a battery pack, the internal battery may break down (for example, deterioration of the battery cell is a factor).
Normally, since the battery pack constitutes a high-voltage power supply circuit in the battery case, when the battery fails, the entire battery pack is replaced.
By the way, in the case of a failure of the battery pack, for example, a part of the battery cells constituting the battery, for example, only one battery cell may be deteriorated to cause a failure.

However, the battery pack has a structure premised on replacement of the entire battery pack. Therefore, even if only one battery cell of a large number of batteries fails, the entire battery pack, that is, the battery pack itself must be replaced.
In this case, the cost of repair is to replace the entire battery pack, which is considerably expensive and imposes a heavy burden on the user.

Therefore, an object of the present invention is to provide a battery pack for an electric vehicle, which can be easily repaired when a part of a large number of batteries fails and the repair cost associated therewith can be low.

Aspect of the present invention is a battery pack of an electric vehicle mounted on the lower part of a vehicle, and the battery pack has a battery case arranged in the lower part of the vehicle and a battery housed in the battery case. , The battery is an electrically parallel battery module group consisting of a group of battery modules in which a large number of battery cells are connected so as to generate a predetermined voltage and are arranged side by side in a battery case. A power supply circuit unit that is connected to the battery case, a module removal structure that allows the battery module inside the battery case to be attached and detached from the bottom of the battery case to the outside of the case, and a power supply circuit unit that is provided outside the case. Each taken-out battery module is provided with a detachable connector portion that enables disconnection of electrical connection, and the connector portion is provided in a power supply side terminal portion provided in the battery module and in the battery case, and is provided in the battery module. It has a power supply side terminal part and a power receiving side terminal part to be attached and detached according to the attachment / detachment work, the battery module further has sensors for detecting the state of the battery module, and the inside of the battery case is further from the sensors. The wirings that transmit the signal of the above are provided, and the sensors and the wirings can be detached from each other by a first terminal portion provided in the battery module and a second terminal portion provided in the battery case. And said.

According to the present invention, in a battery pack, for example, if only one of the battery cells constituting the battery deteriorates and fails, the replacement is not for the entire battery pack but for the battery module group that is placed horizontally. From among them, only the battery module including the failed battery cell may be taken out of the battery case by the module taking-out structure, and the connection with other battery modules may be disconnected by using the connector portion.

As a result, repairs can be performed only on the battery module containing the failed cell, and the cost burden can be reduced.
Therefore, it is easy to repair and the repair cost associated with it is low.

(A) is a perspective view showing a structure of a battery pack according to an embodiment of the present invention, and (b) is a circuit diagram showing an electric circuit of the battery pack. The perspective view which shows the structure which the battery module is attached and detached from the inside of the battery pack mounted on a vehicle. A plan sectional view of the battery case showing various electric components assembled in the battery case. A side sectional view showing a state in which the battery module is removed from the inside of the battery pack. A side sectional view showing a state in which the battery module is installed in the battery pack.

Hereinafter, the present invention will be described with reference to one embodiment shown in FIGS. 1 to 5.
FIG. 1 shows an overall perspective view of a battery pack 7 mounted on an electric vehicle (corresponding to an electric vehicle), FIG. 2 shows a perspective view of a structure in which the battery module 19 can be attached and detached, and FIGS. A cross-sectional view of each part of the structure is shown.
1 in FIG. 1 shows the vehicle body of an electric vehicle, 3 is a pair of left and right side frames extending in the front-rear direction of the vehicle constituting the substructure of the vehicle body 1, and 5 is a pair of crosses assembled between the side frames 3 and 3. Indicates a member.

The battery pack 7 is mounted on the lower part of the vehicle, specifically, the lower part of the vehicle body surrounded by the side frames 3 and 3 and the cross members 5 and 5.
The battery pack 7 includes, for example, a battery case 13 formed in a flat box shape from a tray 9 and a cover 11 joined so as to cover the tray 9 from above as shown in FIGS. 2 to 5, and a battery case. It has a battery 15 (FIG. 1 (b)) housed in 13. Of these, the battery case 13 fits between the side frames 3 and 3 and the cross members 5 and 5. A plurality of installation legs 17 protruding from the tray 9 to the periphery are fastened (for example, fixed by bolts) to the side frame 3 and the cross member 5. That is, the battery pack 7 is installed along the lower part of the vehicle body 1.

A large number of battery cells are connected to the battery 15 housed in the battery case 13. For example, the battery 15 has a structure in which a plurality of cross-shaped battery modules 19 having a predetermined battery capacity determined by using a large number of battery cells are arranged in parallel in the battery case 13, that is, a battery module group. The structure constituting 20 is used (FIG. 1 (b)). A power supply circuit structure 23 (corresponding to the power supply circuit portion of the present application) for connecting the battery modules 19 in parallel and a take-out structure 25 for individually attaching and detaching the battery module 19 to the lower part of the vehicle (to the module take-out structure of the present application) In combination with (equivalent), the battery module 19 can be replaced individually.

That is, the battery module 19 uses, for example, a box-shaped small module 27 in which a predetermined number of battery cells, for example, eight, are connected in series, and the small modules 27 are arranged in a predetermined number, for example, twelve in a row and connected in series. The structure is such that a predetermined voltage is generated (for example, by a bus module). Incidentally, the battery module 19 is assembled with sensors 29 such as a voltage sensor, a temperature sensor, and a current sensor so that the state of the battery module 19 can be detected. A safety switch 31 is also attached (both are shown in FIG. 1 (b)).

A plurality, for example, three of these battery modules 19 are housed in parallel in the battery case 13 in the lateral direction (for example, in the front-rear direction of the vehicle) at predetermined intervals to form a battery module group 20. Then, the three rows of battery modules 19 are electrically connected in parallel via a wiring structure provided in the battery case 13 as shown in FIG. 1B, and a power supply circuit structure for securing the electric power required for the electric vehicle. It constitutes 23. The details of the power supply circuit structure 23 will be described later.

As shown in FIGS. 1 to 5, the take-out structure 25 divides the wall portion of the lower wall portion 9a of the tray 9 corresponding to the battery modules 19 arranged in three rows. The battery module 19 is mounted on the upper surface of the lower wall portion 9b of the three divided pieces. Specifically, each opening 35 formed in the lower wall portion 9a by division has an elongated shape having a size through which the battery module 19 can be inserted. The lower wall portion 9b has, for example, a flange portion 9c as a fixed seat on the entire circumference, and the flange portion 9c and the opening peripheral portion are detachably fastened with a fastener, for example, a bolt 37 (FIG. 2). It has become. That is, the three rows of battery modules 19 have a structure in which the battery module 19 is installed on the lower wall portion 9b and a structure in which the lower wall portion 9b is attached to and detached from the tray 9, so that the battery modules for one row are individually separated from the battery case 13. Only 19 can be taken out of the case and returned to its original position (FIGS. 1 to 5). Incidentally, the structure is such that the flange portion 9c and the opening peripheral edge portion are sealed by, for example, a sealing member 39 provided on the upper surface (entire circumference) of the flange portion 9c (FIG. 4).

Further, the power supply circuit structure 23 is provided with a conductive connector portion 41 (corresponding to the connector portion of the present application) so that the continuity of the battery module 19 can be individually connected and disconnected according to the attachment / detachment work (FIG. 5). ..
As shown in FIGS. 1 to 5, the conductive connector portion 41 is provided at a predetermined position of the battery module 19, for example, a male terminal block provided at each fixed position on the upper surface of both ends of the battery module 19 in the longitudinal direction, for example, P. A female terminal block, for example, a power receiving side terminal, provided on the inner surface of the cover 11 corresponding to the pole and N pole feeding side terminal portions 43a and 43b and the P pole and N pole feeding side terminal portions 43a and 43b. It has parts 44a and 44b. The power feeding side terminal portions 43a and 43b and the power receiving side terminal portions 44a and 44b are attached and detached according to the attachment and detachment work of the battery module 19.

Then, the power receiving side terminal portions 44a and 44b are installed at one end of the cover 11 in the front-rear direction of the vehicle, for example, via various bus bars 49a to 49c along the inner surface of the cover 11 as shown in FIGS. 3 and 4. It is connected in parallel to the energization control unit, for example, the fuse contactor unit 47.
The fuse contactor unit 47 includes, for example, a motor connector 51 (a joint for guiding electric power to the motor) and a charging connector 53 (a joint for receiving electric power from charging equipment) installed at one end in the vehicle front-rear direction in the cover 11. ) (Fig. 3). As a result, the power supply circuit structure 23 is configured with a parallel power supply circuit in which the required power is secured to the maximum (three rows) by the attachment / detachment of the conductive connector portion 41 performed in response to the attachment / detachment work of the battery module 19. Alternatively, a parallel power supply circuit (two rows) lacking a battery module 19 and partially lacking a power source is formed. Incidentally, in the present embodiment, even if one row of battery modules 19 is missing, sufficient electric power for running the electric vehicle is secured.

Similarly to the power line of the battery module 19, the sensors 29 are also installed on the other side of the cover 11 in the vehicle front-rear direction via the removable terminal structure 55 as shown in FIGS. 4 and 5. It is connected to the battery manager unit).
That is, as shown in FIGS. 1 to 3, the terminal block structure 55 is a male terminal tool 57 installed at a predetermined position for each battery module 19, for example, on the upper surface of the battery module 19 adjacent to the power supply terminal portion 43. It has (corresponding to the first terminal portion of the present application) and a female terminal tool 59 (corresponding to the second terminal portion of the present application) provided on the inner surface of the cover 11 corresponding to the terminal tool 57. Sensors 29 of each battery module 19 are connected to each terminal 57. The terminal tool 59 installed on the cover 11 is detachably connected to the terminal tool 57, and has a structure in which the terminal tool 59 is detached according to the detachment work of the battery module 19. Then, the terminal tool 59 and the BMU 56 are connected via a cable 61 wired in the cover 11 which is wiring, so that a signal indicating the state of the battery module 19 is transmitted to the BMU 53 through the cable 61. There is. That is, the terminal block structure 55 has a structure in which the terminal sensors 29 and the cables 61 (wiring) are connected and disconnected according to the attachment and detachment of the battery module 19.

Next, the operation of the battery pack 7 configured in this way will be described.
Here, for example, a case where only one of the battery cells of the battery pack 7 is deteriorated and a failure occurs will be described as an example.
It is assumed that one of the battery cells constituting the battery module 19a arranged on the passenger seat side (left side) of the battery modules 19 arranged in three rows has a failure.

In this case, the safety switch 31 of the target battery module 19 is turned off. Then, as shown in FIGS. 1, 2 and 4, the bolt 37 fixing the target battery module 19, for example, the lower wall portion 9b of the battery module 19a arranged on the passenger seat side, is loosened. The bolt 37 is removed from the peripheral edge of the opening 35.
Subsequently, the lower wall portion 9b is pulled down to the lower part of the vehicle body. As a result, the battery modules 19a for one row installed in the lower wall portion 9b are taken out of the case through the opening 35 of the tray 9.

According to the removal of the battery module 19a, the P-pole and N-pole power supply side terminals 43a and 43b installed in the battery module 19a are the P-pole and N-pole assembled on the cover 11 side (battery case 13). It is separated from the power receiving side terminal portions 44a and 44b. At the same time, the terminal tool 57 attached to the battery module 19a is also separated from the terminal tool 59 attached to the cover 11 side (battery case 13).

As a result, only the row of battery modules 19a including the failed battery cell is removed from the power line and signal line of the normal battery module 19 and taken out from the battery case 13 while leaving the normal battery module 19 as it is. Is done.
Therefore, to deal with the failure, it is only necessary to repair the battery module 19a including the removed failed battery cell.

Of course, when the repaired battery module 19a is inserted into the tray 9 through the opening 35, the power supply side terminals 43a and 43b and the power receiving side terminals 44a and 44b are connected, and the terminal tool 57 and the terminal tool 59 are connected. Then, a parallel power supply circuit is constructed again by the three rows of battery modules 19.
As described above, a plurality of battery modules 19 are housed horizontally in the battery case 13 in parallel, and these battery modules 19 can be individually taken out from the lower part of the battery case to the outside of the case, so that only one battery cell is used. Even if a deteriorated failure occurs, it is not necessary to replace the entire battery pack, and only one row of battery modules 19a including the failed battery cell needs to be replaced or repaired, which bears the cost burden required for replacement or repair. It can be greatly suppressed.

Therefore, if a part of the battery cell breaks down, it is easy to repair and the repair cost associated with it is low.
Moreover, since the tray 9 (lower part of the battery case 13) is divided and the battery module 19 is installed on the divided lower wall portion 9b, the battery module 19 can be easily attached and detached.

In particular, since the power line and signal line of the battery module 19 can be attached and detached by using a removable terminal structure, the power line and signal line can be removed according to the removal work of the battery module 19, which is even easier. The battery module 19 can be attached and detached by the work.
The present invention is not limited to the above-described embodiment, and may be varied and implemented within a range that does not deviate from the gist of the present invention.

1 Body 7 Battery pack 9a Lower wall part 13 Battery case 15 Battery 19 Battery module 20 Battery module group 23 Power supply circuit structure (power supply circuit section)
25 Take-out structure (module take-out structure)
29 Sensors 41 Conductive connector part (connector part)
43a, 43b Power supply side terminal 44a, 44b Power receiving side terminal 57 Terminal tool (first terminal)
59 terminal tool (second terminal part)
61 cables (wiring)

Claims (2)

A battery pack for an electric vehicle mounted on the bottom of the vehicle.
The battery pack has a battery case arranged at the bottom of the vehicle and a battery housed in the battery case.
The battery is
A battery module group composed of a plurality of battery modules in which a large number of battery cells are connected so as to generate a predetermined voltage are housed side by side in the battery case.
A power supply circuit unit configured by electrically connecting the battery modules in parallel,
A module take-out structure that allows the battery modules in the battery case to be individually attached to and detached from the lower part of the battery case to the outside of the case.
Each battery module provided in the power supply circuit section and taken out of the case is provided with a detachable connector section capable of disconnecting the electrical connection .
The connector part
The power supply side terminal provided in the battery module and
It is provided in the battery case and has the power supply side terminal portion and the power receiving side terminal portion to be detached according to the attachment / detachment work of the battery module.
The battery module further includes sensors for detecting the state of the battery module.
The inside of the battery case further includes wirings for transmitting signals from the sensors.
The sensors and the wirings can be attached to and detached from each other by a first terminal portion provided in the battery module and a second terminal portion provided in the battery case.
The battery pack of the electric vehicle is characterized by that. The battery case is configured such that the lower wall portion facing the lower side of the vehicle can be divided into the battery modules arranged in the horizontal direction.
The battery pack for an electric vehicle according to claim 1, wherein the module taking-out structure is provided with the battery module for each of the divisible lower wall portions.

Images