JP6752404B2 - Battery pack - Google Patents

Description

The present invention relates to a battery pack used for in-vehicle use and the like.

Conventionally, in the field of rechargeable secondary batteries, aqueous solution batteries such as lead batteries, nickel-cadmium batteries, and nickel-hydrogen batteries have been the mainstream. However, as electric devices have become smaller and lighter, attention has been paid to lithium secondary batteries having a high energy density, and their research, development and commercialization have been rapidly promoted.

On the other hand, due to the problems of global warming and depleted fuel, electric vehicles (EVs) and hybrid electric vehicles (HEVs) that partially assist a part of the drive with an electric motor have been developed by each automobile manufacturer and have high capacity and high output as their power source. Secondary batteries are being sought after. As a power source that meets such demands, a non-aqueous lithium secondary battery having a high voltage is drawing attention. In particular, since the square lithium secondary battery is excellent in volumetric efficiency when packed, expectations for the development of a square lithium secondary battery for HEV or EV are increasing.

Easy handling by assembling a cell control unit that has the voltage detection function and voltage control function of the secondary battery or the input / output function of the detection signal and control signal to the module case that houses a large number of secondary batteries. In addition, a battery device for mounting on a mobile body has been proposed with improved reliability. (Patent Document 1)

Japanese Unexamined Patent Publication No. 2000-228178

In recent automobiles, battery packs are required to be as small as possible in order to improve the mountability. The pack structure (battery device structure) disclosed in Patent Document 1 includes a large number of secondary batteries and a cell controller as an all-in-one unit. However, miniaturization of this pack structure is not considered. Therefore, an object of the present invention is to provide a battery pack having a reduced boat height and a smaller size.

In order to solve the above problems, for example, the configuration described in the claims is adopted.

The present application includes a plurality of means for solving the above problems. For example, a battery group in which a plurality of storage batteries are stacked, a block member arranged at one end of the battery group, and a surface on one side thereof. In a battery pack provided with a connector and a control board for controlling charging / discharging of the battery group, the block member has a recess so that the control board accommodates the connector in the recess. A battery pack characterized by facing the block member.

According to the present invention, the battery pack can be reduced in height and size by accommodating the side of the control board having the connector in the recess of the block member arranged at one end of the battery group in which a plurality of storage batteries are stacked.

External perspective view of the battery pack. An exploded perspective view of the battery pack. An exploded perspective view of the battery pack as viewed from the opposite direction of FIG. Perspective view of the side plate. The perspective view which shows the structure of the terminal block. A perspective view seen from the opposite direction of FIG. A perspective view seen from the back side of FIG. The perspective view which shows the structure of the contactor box. A perspective view seen from the back side of FIG. The figure which showed the flow path formed by the side plate and the case body. The figure which showed the circulation path of the refrigerant which circulates by a fan. The perspective view which shows the contactor box in 2nd Embodiment. The perspective view which shows the contactor box seen from the back side direction of FIG. The figure which showed the circulation path of the refrigerant which circulates by a fan in 2nd Embodiment. The figure which shows the controller 12.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

<< Embodiment 1 >>
FIG. 1 is an external perspective view of a battery pack as an embodiment. The battery pack 1 includes a case composed of a case body 2 and an upper cover 3. HV terminals 21 and 81 are provided at both ends of the upper surface of the battery pack 1 in the longitudinal direction, respectively. The HV terminals 21 and 81 are external terminals, and the battery pack 1 supplies power to an electric vehicle, a hybrid electric vehicle, or an electric device by connecting an HV cable to the HV terminals 21 and 81. In this embodiment, the HV terminal 21 is on the (−) side and the HV terminal 81 is on the (+) side.

A signal connector 4 is arranged on the side surface of the battery pack 1. The signal connector 4 is a signal connector of the controller of the battery pack 1, and is connected to the controller on the vehicle side to exchange information and receive power supply.

FIG. 2 is an exploded perspective view of the battery pack 1 shown in FIG. When using the terms up, down, left, right, front and back, follow the directions shown in the lower left of the figure. The case body 2 has a bottom portion 2a and is a box-shaped member having an opening at the top. One end side of a region in which a plurality of square secondary batteries 5 and end plates 7 that pressurize partition members 6 interposed between adjacent square secondary batteries 5 from both ends in the stacking direction are housed in the case body 2. The contactor box 8 is housed in the (rear side). A terminal block 9 is arranged at the end (front side) of the contactor box 8 on the opposite side of the rectangular secondary battery 5 in the stacking direction. Side plates 10 are arranged on both sides of the short side surface of the rectangular secondary battery group. Further, a bus bar case 11 is arranged on the upper upper cover 3 side of the rectangular secondary battery group.

The rectangular secondary battery is, for example, a lithium ion secondary battery. In the square secondary battery 5, a power generation element (not shown) is housed in a battery container formed by joining a battery can 52 and a battery lid 51, and a non-aqueous electrolytic solution is injected. A positive electrode external terminal 53 is provided near one end side in the width direction (front-rear direction) of the battery lid 51, and a negative electrode external terminal 54 is provided near the other end side. The positive and negative electrode external terminals 53 and 54 are connected to the positive and negative electrodes of the power generation element, respectively. The positive and negative electrode external terminals 53 and 54 project upward from the flat upper surface of the battery lid 51.

The square secondary battery 5 has a bottom surface opposite to the battery lid 51, a large area front and back surfaces facing each other in the left-right direction, and a pair of side surfaces having a small area facing the front-rear direction. The square secondary battery 5 is linearly arranged so that the positive electrode external terminals 53 and the negative electrode external terminals 54 are alternately arranged on opposite sides with the front and back surfaces facing each other.

A partition member 6 is arranged between the square secondary batteries 5 to form a battery module 1R. The partition member 6 is also arranged on the left side of the square secondary battery 5 on the one end side (rear side) and on the right side (front and rear ends in the arrangement direction) of the square secondary battery 5 on the right end side. The partition member 6 has a plate shape and is formed of, for example, a resin such as PBT (polybutylene terephthalate).

A plurality of the rectangular secondary batteries 5 are arranged so as to be aligned in one direction. At this time, the square secondary batteries 5 are arranged so that the wide surfaces of the square secondary batteries 5 face each other between the pair of end plates 7 arranged apart from each other. The pair of end plates 7 are arranged so as to be in surface contact with the partition plates 6 located on the outermost side, and pressurize a plurality of rectangular secondary batteries 5 inward. At this time, in order to keep the plurality of rectangular secondary batteries 5 in a pressurized state, side plates 10 are fastened to the pair of end plates 7. At this time, the main body of the side plate 10 is in contact with the short side surface of the rectangular secondary battery.

FIG. 3 is an exploded perspective view of the battery pack 1 as viewed from the opposite direction of FIG. As shown in this figure, the controller 12 (control board 12) is housed in the terminal block 9 with the surface on which the communication connector 12a, the main relay drive connector 12b, and the voltage detection connector 12c are arranged facing. It is integrated with the terminal block 9. With such a structure, the thickness of the connector arranged on the controller 12 can be suppressed, and the battery pack 1 can be prevented from becoming large in the front-rear direction. Further, as will be described later, since the terminal block 9 has a structure in which the fan 22 is built in, the thickness of the fan 22 can be suppressed, and the battery pack 1 can be prevented from becoming larger in the front-rear direction. It becomes. The detailed structure of the controller 12 will be described in detail with reference to FIG.

Next, the side plate 4 will be described. FIG. 4 is a perspective view of the side plate. The side plate 10 has an L-shape, and is bent from the main body 10a in contact with the short side surface of the square secondary battery 5, the fixing portion 10b that is bent from the main body and fixed to the case, and the main body. It is composed of a fastening portion 10c to be fastened to the end plate 7. The fastening portion 10c of the side plate is provided with a hole 10d for inserting a bolt, and is fastened to the fastening portion of the end plate 7 by a bolt. Further, the fixing portion 10b of the side plate 10 is provided with a hole 10e for inserting a bolt, and the battery module 1R is fixed to the case main body 2 by being fastened to the case main body 2 by the bolt 13. That is, since the side plate 10 provided of metal is in direct contact with the side surface of the battery module 1R and the side plate 10 is in direct contact with the case body 2, the heat of the square secondary battery 5 is transferred to the case. The number of routes to flow to the main body 2 will increase. Therefore, with such a structure, cooling of the battery module 1R is further promoted.

Subsequently, the terminal block 9 which is a feature of the present invention will be described. The perspective views of the terminal block 9 are shown in FIGS. 5 to 7. 5 and 6 are views of the terminal block from the side where the controller 12 is not arranged, and FIG. 7 is a view of the terminal block 9 from the side where the controller 12 is arranged. The terminal block 9 is provided with an HV terminal 21 on the (-) side, a fan 22, and a controller 12. The fan 22 is housed in a space provided in the center of the lower part of the terminal block 9. On the other hand, the controller 12 has a communication connector 12a, a main relay drive connector 12b, and a voltage detection connector 12c connected by soldering. Further, the controller 12 has a shunt resistor 12d screw-fixed on the control board. The controller 12 is attached so that the side having the connector is housed in the terminal block recess 9a provided in the terminal block 9, and is attached to the surface of the terminal block opposite to the battery module by bolts. The controller 12 is electrically connected to an inter-cell bus bar to which the square secondary battery 5 is connected, and measures and monitors the voltage of each square secondary battery 5. The inter-cell bus bar is joined to the positive electrode external terminal 53 of one square secondary battery 5 adjacent to the stacking direction of the square secondary battery 5 and the negative electrode external terminal 54 of the other square secondary battery 5 by welding or the like, and the battery All of the square secondary batteries 5 constituting the module 1R are connected in series. A circuit for monitoring and controlling the entire battery pack 1 is mounted on the controller 12.

Further, the terminal block 9 is provided with a partition plate 24 and a protruding portion 25. The partition plate 24 is provided to close the gap with the case main body 2, and the protruding portion 25 is provided to close the gap with the battery module 1R. Further, the terminal block 9 is provided with an opening 26. The refrigerant sucked by the fan 22 moves through the opening 26 to the flow path side formed by the side plate fixing portion 10b and the case body 2.

Here, the controller 12 will be described in detail with reference to FIG. As described above, the communication connector 12a, the main relay drive connector 12b, and the voltage detection connector 12c are provided on the controller 12, respectively. The communication connector 12a and the main relay drive connector 12b are light electrical connectors, and the voltage detection connector 12c is a high electrical connector. Therefore, in the present embodiment, the light electric connector is divided into the left side of the controller 12, and the high electric connector is divided into the right side of the controller 12. With such a configuration, it is possible to suppress noise from being applied from the high-voltage connector to the low-voltage connector. In this embodiment, the controller 12 is divided into a right side and a left side, but the present invention is not limited to the right side and the left side. If the controllers 12 can be separately arranged on the pair of opposite end sides, the effect of suppressing noise from being applied to the weak electric system can be obtained. Further, in the present embodiment, the number of connectors is three, but in consideration of miniaturization in the front-rear direction, even if the number of connectors provided in the controller 12 is one, it is two, and more. It may be.

Further, in the present embodiment, the shunt resistor 12d is provided on the upper side of the controller 12. With such a configuration, the shunt resistor 12d is located close to the terminal of the square secondary battery, and the bus bar wiring can be simplified and shortened.

Subsequently, a perspective view of the contactor box 8 is shown in FIGS. 8 and 9. FIG. 8 is a view of the contactor box 8 from the front, and FIG. 9 is a view of the contactor box 8 from the rear. The contactor box 8 is provided with an HV terminal 81 on the (+) side, a fuse 82, and a relay 83. By storing the fuse 82 and the relay 83 in the contactor box 8 in this way, the fuse 82 and the relay 83 can be collectively attached to the case body 2, and the workability is improved. As shown in FIG. 9, the contactor box 8 is lightened to reduce the weight.

Subsequently, the flow path structure of the present invention will be described. The flow path formed by the side plate 10 and the case body is shown in FIG. The fixing portion 10b is fixed to the case body 2 with bolts 13 in a state where the short side surface of the square secondary battery 5 is in contact with the side plate 10. The left side flow path 14a and the right side flow path 14b through which the refrigerant flows can be formed on the main body portion 10a and the fixing portion 10b of the side plate 10 and the side surface of the case. The left flow path 14a is closed in the depth direction of the drawing by the partition plate 24 of the terminal block 9. Therefore, air flows through the fan 22 without leakage, so that the cooling efficiency of the battery module 1R is improved.

The battery pack 1 of the present invention is a system in which air circulates in the space formed by the case body 2 and the upper cover 3. The circulation path of the refrigerant circulated by the fan 22 is shown in FIG. As shown in FIG. 11, the cooling flow path of the present invention is classified into several flow paths. Specifically, the flow paths 14 (14a, 14b) formed by the side plate 10 and the case body 2, and the flow paths from the partition plate of the terminal block 9 to the protruding portion 25 of the terminal block 9, which are terminals. A flow path 15a provided between the base 9 and the end plate 7, a flow path 15b connected to the fan 22 inside the terminal block 9, a flow path 16 formed by the contactor box 8 and the end plate 7, and a contactor box. It is a flow path 17 formed between the 8 and the case body 2. A fan 22 is used to circulate the refrigerant in these flow paths. The heat transferred from the short side surface of the rectangular secondary battery 5 to the side plate is transferred to the circulating refrigerant. One of the features of the present invention is a structure in which the refrigerant is applied to the side plate 10 to remove heat from the side plate 10 instead of flowing the refrigerant between the rectangular secondary batteries 5. With such a structure, the temperature of the refrigerant in the case becomes uniform, so that the side plate 10 can be cooled efficiently. Since the side plate 10 is fixed to the case body 2, the heat transferred from the short side surface of the rectangular secondary battery 5 to the side plate 10 is transferred to the case body 2. Since the side plate 10 is cooled by transferring heat to the case body 2, the rectangular secondary battery can be cooled.

Further, when a current flows through the relay 83 arranged in the contactor box 8, the temperature of the relay rises due to heat generation. Since the refrigerant circulated by the fan flows on both sides of the contactor box 8, the relay 83 can be cooled. Further, one of the features of the present invention is that a flow path 15b connected to the fan 22 is provided inside the terminal block 9. The fan 22 draws the refrigerant into the flow path 15b inside the terminal block 9. At this time, since the controller 12 is arranged so as to face each other via the fan 22 and the terminal block 9, sufficient cooling is possible even if the electronic components of the controller 12 generate heat. In the present embodiment, the terminal block 9 is interposed between the fan 22 and the controller 12, but the fan 22 and the controller 22 may communicate with each other without the member of the terminal block 9 being interposed between them. .. With such a structure, the cooling of the controller 12 is further promoted.

Further, in the present invention, the controller 12 is housed by utilizing the thickness of the terminal block 9, but another block member (in the case of a battery pack without the terminal block 9, the end plate 7) housed in the battery pack is used. Etc.) may be used to store the controller 12. Even with such a configuration, the battery pack 1 can be miniaturized in the front-rear direction.

The present invention will be briefly summarized above. In the present invention, the controller, which has been conventionally arranged on the terminal side (upper surface side) of the square secondary battery 5 in order to improve the connection efficiency of the voltage detection line, is brought to the side surface side of the square secondary battery 5. The advantage is that the battery pack 1 is miniaturized in the vertical direction. On the other hand, if the controller 12 is simply brought to the side surface side of the rectangular secondary battery 5, it will be difficult to connect the voltage detection line and other wiring to the controller 12, so the connectors (12a, 12b, 12c) are connected to the controller 12. ) Was provided, but there was a problem that the controller 12 became thicker by that amount. Therefore, the battery pack 1 described in the present invention includes a battery group (1R) in which a plurality of storage batteries (5) are stacked, a block member (7, 9) arranged at one end of the battery group (1R), and one side thereof. The block member (7, 9) has a recess (9a), and has a connector (12a, 12b, 12c) on the surface of the battery group (1R) and a control board (12) for controlling charging / discharging of the battery group (1R). The control board (12) is opposed to the block member (7, 9) so that the connector (12a, 12b, 12c) is housed in the recess (9a). With such a configuration, the connectors (12a, 12b, 12c) of the controller 12 can be housed in the members (terminal block 9 and end plate 7) that originally require thickness to be compact, and the upper and lower parts of the battery pack 1 can be made compact. It is possible to reduce the size in the direction and the front-back direction.

Further, the block member of the present invention is a terminal block (9) in which terminals are arranged. Since it is necessary to press the end plate 7 with a large force to some extent, the terminal block 9 which does not apply such a large force has less influence on the substrate and the yield is improved.

Further, in the battery pack described in the present invention, the control board (12) has two connectors (12a, 12c), and one connector (12c) is connected to a member having a higher voltage than the other connector (12a). The control board (12) is arranged so that one connector (12c) is arranged on one side surface side of the battery group (1R) and the other connector (12a) is arranged on the other side surface side of the battery group (1R). It is provided. With such a configuration, the wiring of the light electric system and the wiring of the strong electric system can be separated, and the influence of noise of the wiring of the light electric system due to the wiring of the strong electric system can be reduced. Further, by arranging the light electric system wiring and the strong electric system wiring in the left-right direction of the controller 12, the wiring work can be performed in the flow paths 14a and 14b having a certain space, so that the workability is improved.

Further, the control board (12) described in the present invention has a shunt resistor (12d), and the shunt resistor (12d) is provided on the control board (12) so as to be arranged on the upper surface side of the battery group (1R). Be done. With such a configuration, the shunt resistor 12d is located close to the terminal of the square secondary battery, and the bus bar wiring can be simplified and shortened.

Further, the terminal block (9) described in the present invention has a built-in fan (22), and further, the terminal block (9) has a flow path (15d) of the fan (22) inside. With such a configuration, even if the electronic components of the controller 12 generate heat, sufficient cooling is possible.

<< Embodiment 2 >>
Subsequently, the second embodiment will be described. The major difference between this embodiment and the first embodiment is that the cooling flow path on the rear side of the contactor box 8 is eliminated. With such a structure, it is possible to prevent the temperature of the refrigerant from rising and to cool the controller 12 more efficiently.

The second embodiment will be described with reference to FIGS. 12 to 14. FIG. 12 is a view of the contact box 8 viewed from the front side, and FIG. 13 is a view of the contactor box 8 viewed from the rear side. In the present embodiment, the contactor box 8 is provided with two partition plates 84 and 85 in order to eliminate the cooling flow path on the rear side of the contactor box 8. More specifically, partition plates 84 and 85 were installed on both sides of the contactor box 8 in the width direction toward the case body 2 side. Since the partition plates 84 and 85 serve as a wall between the flow paths 14a and 14b and the flow path 17 in the first embodiment, the refrigerant does not pass through the back side of the contactor box 8. Therefore, the pressure loss of the entire flow path is reduced, and the controller 12 can cool the square secondary battery 5 more effectively.

FIG. 14 is a diagram showing a cooling flow path according to the present embodiment. The flow path of the present embodiment is basically the same as that of the first embodiment, but is described in the first embodiment by the right partition plate 84 and the left partition plate 85 provided in the contactor box 8. The flow path connected to the flow path 17 will be blocked. Therefore, the refrigerant by the fan 22 circulates around the flow paths 14, 15 and 16 around the battery module 1R, and the square secondary battery 5 can be cooled more efficiently.

The above is a brief summary of this embodiment. In the battery pack described in the present embodiment, a contactor box (8) is arranged on the other end side of the battery group (1R), and a flow path is arranged between the contactor box (8) and the battery group (1R). To. Further, the structure is such that the right partition plate 84 and the left partition plate 85 provided in the contactor box 8 block the flow path connected to the flow path 17 described in the first embodiment. With such a structure, the pressure loss in the flow path is reduced, and the refrigerant can cool the controller 12 more efficiently and the square secondary battery 5.
Although the embodiments of the present invention have been described in detail above, the present invention is not limited to the above-described embodiments, and various designs are designed without departing from the spirit of the present invention described in the claims. You can make changes. For example, the above-described embodiment has been described in detail in order to explain the present invention in an easy-to-understand manner, and is not necessarily limited to the one including all the described configurations. Further, a part of the configuration of one embodiment can be replaced with the configuration of another embodiment, and the configuration of another embodiment can be added to the configuration of one embodiment. Further, it is possible to add / delete / replace a part of the configuration of each embodiment with another configuration.

1 Battery pack 2 Case body 3 Top cover 5 Square secondary battery 8 Contactor box 9 Terminal block 9a Terminal block recess
10 Side plate 12 Controller 12a Communication connector 12b Main relay drive connector 12c Voltage detection connector 12d Shunt resistor 14, 15, 16, 17 Flow path 21 HV terminal (-) side (external terminal)
22 Fan 24 Partition plate 25 Protruding part 81 HV terminal (+) side (external terminal)

Claims (3)

A control that controls charging / discharging of the battery group by having a battery group in which a plurality of storage batteries are stacked , a terminal block in which terminals are arranged at one end of the battery group, and a connector on one side. In a battery pack with a board and
The terminal block has a recess and
The control board is attached to the surface of the terminal block opposite to the battery group so that the connector is housed in the recess so as to face the terminal block .
The terminal block has a built-in fan so as to face the control board, has a flow path connected to the fan inside the terminal block, and the refrigerant is drawn into the flow path by the fan. Battery pack. In the battery pack according to claim 1 ,
The control board has two connectors.
One connector is connected to a member with a higher voltage than the other connector,
A battery pack, characterized in that the one connector is provided on one side surface side of the battery group, and the other connector is provided on the control board so as to be arranged on the other side surface side of the battery group. In the battery pack according to any one of claims 1 and 2 .
The control board has a shunt resistor and
A battery pack characterized in that the shunt resistor is provided on the control board so as to be arranged on the upper surface side of the battery group.

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