JP6985103B2 - Busbar module - Google Patents

Description

The present invention relates to a bus bar module used in a battery stack having a plurality of battery bodies.

This type of busbar module has a module body that holds a busbar that interconnects the electrode terminals of adjacent battery bodies. As the module main body, for example, the one described in Patent Document 1 is known. The document discloses a technique of connecting a plurality of unit modules to form a module main body in order to correspond to a plurality of battery bodies.

Japanese Unexamined Patent Publication No. 2013-54995

However, when a plurality of unit modules are connected to form a module main body as in the prior art, the unit modules at both ends are usually provided with terminals for taking out power from the battery stack. Therefore, it is necessary to prepare multiple unit modules of different types. Therefore, as the types of unit modules increase, there arises a problem that the manufacturing cost thereof increases. Further, when the number of connected unit modules increases, there arises a problem that the assembly workability is lowered.
Therefore, the present invention has been made by paying attention to such a problem, and in a bus bar module having a module main body configured by connecting a plurality of unit modules, the types of unit modules are reduced and the types of unit modules are reduced. An object of the present invention is to provide a bus bar module capable of suppressing a decrease in assembly workability.

In order to solve the above problems, the bus bar module according to one aspect of the present invention is a bus bar module attached to a battery stack composed of a plurality of battery bodies having a pair of positive and negative electrode terminals, and adjacent to each other. A module main body including a bus bar holding portion for holding a bus bar connecting the electrode terminals of the battery bodies is provided, and the module main body is composed of a plurality of unit modules connected in an arrangement direction of the plurality of battery bodies. In the unit modules adjacent to each other in the arrangement direction, the bus bar is arranged in the bus bar holding portion so as to connect the adjacent unit modules to each other, and the bus bar is arranged at the end opposite to the side on which the bus bar is arranged. Engagement portions that engage adjacent unit modules with each other are provided, and two end modules located at both ends of the module body, an intermediate module located between the two end modules, and an intermediate module. The two end modules are composed of unit modules having the same configuration, and one end module and the other end module correspond to each other in a state of being relatively rotated 180 degrees in a plan view. It is characterized in that it is connected to an intermediate module.

According to the bus bar module according to one aspect of the present invention, the two end modules are composed of unit modules having the same configuration, and one end module and the other end module are relatively 180 in plan view. In the rotated state, it is connected to the corresponding intermediate module. That is, the end module is composed of one kind of unit module. Therefore, when the module main body is configured by connecting a plurality of unit modules, the types of unit modules can be reduced.
Further, in the plurality of unit modules, the bus bar is arranged in the bus bar holding portion so as to connect the adjacent unit modules to the adjacent unit modules in the arrangement direction, and the bus bar is arranged on the side opposite to the side on which the bus bar is arranged. Since the end portion is provided with an engaging portion that engages the adjacent unit modules with each other, it is possible to stabilize the connection posture between the plurality of unit modules. Therefore, even if the number of connected unit modules increases, it is possible to suppress a decrease in assembly workability.

It is a schematic perspective view explaining one embodiment of the battery stack which attached the bus bar module which concerns on one aspect of this invention. 1 is a schematic circuit diagram of the battery stack of FIG. 1, where FIG. 1A shows the entire battery stack and FIG. 1B shows a schematic circuit of one battery module constituting the battery stack. It is a schematic plan view explaining one embodiment of the bus bar module mounted on the battery stack of FIG. 1, and the figure shows the state which the cover for the bus bar is removed from the battery stack of FIG. It is a schematic front view explaining one Embodiment of the module main body which comprises the bus bar module of FIG. 4 is a schematic plan view showing a main part of the module body in FIG. 4, where FIG. 4A shows a state in which unit modules constituting the module body are connected to each other, and FIG. 4B is a unit constituting the module body. It shows the state where the modules are separated from each other. It is a schematic plan view which shows the main part of the bus bar module in FIG. It is a figure explaining the comparative example, and the figure shows an example which does not provide the engaging part which engages with each other of adjacent unit modules.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings as appropriate. In this embodiment, an example of a battery stack constituting an in-vehicle power supply device of an electric vehicle will be described. That is, the battery stack of the present embodiment is used as an in-vehicle power supply device, and supplies DC power converted into three-phase AC power to a motor generator via an inverter in response to a request from the system side of the vehicle.

Further, the battery stack of the present embodiment stores the DC power converted from the three-phase AC power generated by the generator via the inverter when charging is required, depending on the judgment of the system side of the vehicle. However, the electric vehicle includes a hybrid electric vehicle in which an engine and an electric motor, which are internal combustion engines, are the driving source of the vehicle, and a genuine electric vehicle in which the electric motor is the sole driving source of the vehicle.
In addition, each drawing is schematic. Therefore, it should be noted that the relationship, ratio, etc. between the thickness and the plane dimension are different from the actual ones, and there are parts where the relationship and ratio of the dimensions are different between the drawings. Further, the embodiments shown below exemplify devices and methods for embodying the technical idea of the present invention, and the technical idea of the present invention describes the material, shape, structure, and arrangement of components. Etc. are not specified in the following embodiments.

As shown in FIG. 1, the battery stack 1 of the present embodiment is configured as a lithium ion battery device including a plurality of battery modules 20 formed in the same shape. The bus bar module 10 is mounted on the upper surface of the battery stack 1 in the figure. The entire bus bar module 10 is covered with a removable cover 15 for the bus bar. Each battery module 20 includes a flat rectangular parallelepiped case 21. A plurality of battery cells 22 (see FIG. 2B), which are flat lithium-ion secondary batteries, are housed in the case 21.

The plurality of battery modules 20 are arranged in multiple stages in the longitudinal direction L of the bus bar module 10 so that the side surfaces of the cases of the adjacent battery modules 20 are in contact with each other or separated by a slight gap. The longitudinal direction of each battery module 20 (vertical direction in the figure) is the thickness direction of the bus bar module 10, and the mounting surface 2 (positive electrode terminal shown in FIG. 3) formed on one of the longitudinal directions of each battery module 20. The surface 2) on which 3 and the negative electrode terminal 5 protrude is flush with each other. The bus bar module 10 is mounted on the mounting surface 2 so as to cover the positive electrode terminal 3 and the negative electrode terminal 5. As a result, each battery module 20 is connected in series using the bus bar module 10.

As shown in FIG. 2A, the battery stack 1 has a stack 1L on the high potential side and a stack 1R on the low potential side. The positive electrode terminal P and the negative electrode terminal N of the left and right stacks 1L and 1R are electrically connected to an external load (for example, an external terminal of an inverter) via a cable (not shown). An SD switch (service disconnect switch) 6 is provided between the left and right stacks 1L and 1R. The SD switch 6 is a safety device for ensuring safety during maintenance and inspection of the battery stack 1, and is composed of an electric circuit in which a switch and a fuse are electrically connected in series.

As shown in FIG. 2B, each battery module 20 has a plurality of battery cells 22 built in the case 21. Each battery cell 22 has a power generation element in which a positive electrode and a negative electrode containing an active material that occludes and releases lithium are laminated via a separator. Each battery cell 22 is a laminated battery in which the power generation element is housed in an insulating outer body together with an electrolytic solution. Each battery module 20 is configured by connecting a plurality of battery cells 22 in series or in parallel, or in combination of series and parallel. Here, the exterior body may be, for example, one in which the periphery of two laminated films is heat-sealed.

In this example, the plurality of battery cells 22 built in each battery module 20 are configured by further connecting two sets of battery cells 22 connected in parallel in series, as shown in the figure. Each battery module 20 is electrically connected to a battery control device (not shown) via a connection line such as a harness. The battery control device executes a process related to management and control of the state of the battery stack 1. The processes executed by the battery control device include measurement of the voltage and current of the battery stack 1, calculation of the state of charge (SOC) and state of health (SOH) of the battery stack 1, and each of them. Measurement of the temperature of the battery module 20, measurement of the voltage of each battery cell, adjustment processing of the storage amount of each battery cell, and the like are executed.

In each battery module 20, a positive electrode terminal 3 for deriving the maximum potential of a plurality of predeterminedly connected battery cells 22 to the outside and a negative electrode terminal 5 for deriving the minimum potential to the outside are external to the case 21. It is provided exposed to. Further, in the present embodiment, an intermediate terminal 4 for taking out an intermediate potential is provided in the center of each battery module 20. As a result, the positive electrode terminal 3, the negative electrode terminal 5, and the intermediate terminal 4 are arranged in a projecting state from one mounting surface 2 in the longitudinal direction of each battery module 20. When viewed from the terminal side of each battery module 20, the battery stack 1 has positive electrode terminals 3 and negative electrode terminals 5 of each battery module 20 arranged alternately.

As shown in FIG. 3, each battery module 20 is connected in series by the bus bar module 10. In the example of the present embodiment, the stack 1L on the high potential side and the stack 1R on the low potential side are connected in series by two bus bar modules 10 so as to cover the terminal portion of each stack. In this example, a removable cover 15 is attached to each of the left and right stacks 1L and 1R bus bar modules 10.
Each busbar module 10 includes a module body 11 made of an insulating material (eg, an insulating synthetic resin). As shown in the figure, a plurality of bus bars 12 are integrally fitted in a predetermined bus bar holding portion in the module main body 11. The bus bar 12 is a flat plate-shaped metal member having a rectangular shape. Each bus bar 12 is connected to each of the adjacent terminals 3 and 5 of the battery modules 20 when the bus bar module 10 is mounted on the battery stack 1, so that the battery modules 20 can be efficiently and integrally connected in series. It has become.

Here, the module main body 11 of the present embodiment is composed of a plurality of unit modules 11A and 11B corresponding to each of the battery modules 20 constituting the battery stack 1. The plurality of unit modules 11B have a split structure in which one of the unit modules adjacent to each other can be attached to and detached from each other even in a posture of being rotated by 180 ° along the mounting surface 2.
Specifically, as shown in FIG. 4, each of the left and right stacks 1L and 1R is composed of a set of a total of 5 unit modules, and the entire stack 1 is composed of a total of 10 unit modules. In the present embodiment, the first unit module 11A for deriving the positive electrode terminal P and the negative electrode terminal N is used on both sides of the left and right stacks 1L and 1R. Further, as the other portion, a second unit module 11B having an engagement structure that can be assembled in a posture rotated by 180 ° along the mounting surface 2 with respect to the adjacent unit modules 11A and 11B is used. There is.

In the figure, in the unit module 11A, the reference posture is indicated by reference numeral 11A1, and the posture rotated by 180 ° along the mounting surface 2 is indicated by reference numeral 11A2. Similarly, in the unit module 11B, the reference posture is indicated by reference numeral 11B1, and the posture rotated by 180 ° along the mounting surface 2 is indicated by reference numeral 11B2.
Here, in the bus bar module main body 10, the sensor mounting area (temperature sensor mounting portion) 13 and the harness storage area are shown in FIG. 5 as shown in the plan view of the portion mounted on the stack 1L on the high potential side. 14 and 14 are integrally formed by injection molding or the like. The harness storage region 14 also serves as a wiring path for a voltage detection electric wire (not shown) of the battery module 20, and the bus bar module 10 is formed in a concave groove having a substantially rectangular cross section along the longitudinal direction L thereof. Ru.

In the figure, the outer peripheral shape of each unit module is indicated by a “thin solid line”, and the wall surface portion (the portion having a height) integrally formed by injection molding or the like is indicated by a “thick solid line”. Further, the three circles for each unit module indicated by the "thin solid line" face the two through holes Th formed at positions facing the positive electrode terminal 3 or the negative electrode terminal 5, respectively, and the intermediate terminal 4 in the center. The through hole 4h formed at the position is shown, and the floor surface portion is shown except for the wall surface portion and the portion where the through hole is formed. The stack 1R on the low potential side has a shape inverted in the left-right direction from the stack 1L on the high potential side, and is not shown.

In the sensor mountable area 13, for example, as shown in the image by the alternate long and short dash line in FIG. 6, a temperature sensor that detects the temperature of the battery module 20 is stored at a position according to the specifications. The temperature sensor of this embodiment is a thermistor 30. The end of the sensor body 31 on the harness 32 side of the thermistor 30 is formed so as to be continuous with the harness storage area 14.
In the mounted thermistor 30, the mounting portion 33 at one end is connected to the intermediate terminal 4, and the harness 32 led out from the other end is connected to a battery control device (not shown) via the harness storage area 14. In the example shown in FIG. 3, the thermistor 30 is mounted on all the battery modules 20 constituting the battery stack 1, but the number of thermistors 30, the mounting position, and the like are determined according to the specifications. It is installed as appropriate.

Each thermistor 30 is connected to a temperature detection circuit (not shown) built in a battery control device (not shown) that monitors the battery stack 1 via a harness 32. The battery control device monitors the temperature of the battery module 20 by the thermistor 30 at any time. The battery control device calculates the maximum temperature, the minimum temperature, the average temperature, etc. from the detected values of the thermista 30, monitors the state of each battery module 20, manages and controls the state, and puts the battery stack 1 in the upper control device. Notifies charge / discharge control information such as the status of and the allowable charge / discharge power.

In the bus bar module 10 of the present embodiment, the battery module 20 has an intermediate terminal 4 for taking out the intermediate potential of the battery module 20 at a position between the positive and negative terminals 3 and 5, and the thermista 30 has a mounting portion 33 at one end. Is connected to the intermediate terminal 4 and the harness 32 led out from the other end is connected to the battery control device. Therefore, according to the bus bar module 10 of the present embodiment, the intermediate terminal 4 of each battery module 20 is a battery module. Since the terminals are connected to the intermediate potentials of the plurality of battery cells 22 stored in 20, the temperature detection accuracy by the thermista 30 is improved.

Here, in the module main body 11 of the present embodiment, an engaging portion 16 that engages the adjacent unit modules 11A and 11B with each other is formed only at the engaging portion forming position indicated by the reference numeral K in FIG. Has been done. In addition, in FIG. 6 and FIG. 6, the image of the engaging portion 16 is illustrated by “=”.
Specifically, as shown in FIG. 5, in the engaging portion 16, the engaging portion forming position K is such that the bus bars 12 are arranged in the bus bar holding portions of the adjacent unit modules 11A and 11B in a plan view. It is provided only at the end opposite to the side. In the present embodiment, each engaging portion 16 has an engaging convex portion 17 provided on one of the adjacent unit modules 11A and 11B and an engaging concave portion provided on the other of the adjacent unit modules 11A and 11B. It is composed of a set of 18.

In the present embodiment, the engaging convex portion 17 is formed in the shape of a claw having an inclined surface at the tip end, and the engaging concave portion 18 has a concave step portion that can engage with the claw of the engaging convex portion 17. As a result, when the claw of the engaging convex portion 17 is inserted into the concave step portion of the engaging concave portion 18, the claw can be smoothly fitted along the slope of the hook claw, and after fitting, the claw shape is the concave step portion. It is prevented from falling off unexpectedly by being caught in. The engaging convex portion 17 and the engaging concave portion 18 are in a fitted state with a gap that is slightly movable in the longitudinal direction L of the bus bar module 10, thereby causing a cumulative error during assembly. It is possible to better suppress the deterioration of assembly workability by absorbing the above.

Further, in the present embodiment, as shown in FIG. 3, the bus bar 12 is provided with fitting recesses 12d formed in a rectangular groove shape at a total of four locations at the upper and lower positions of the terminals 3 and 5 respectively. There is. On the other hand, as shown by a thick black line in FIG. 5, a rectangular convex shape is formed on the side of the module main body 11 at a position facing each of the fitting recesses 12d in the bus bar holding portion on which each bus bar 12 is mounted. The fitting convex portion 11t is formed so as to fit into the fitting concave portion 12d.
Thereby, according to the present embodiment, when the bus bar 12 is integrally fitted in the predetermined bus bar holding portion, the adjacent unit modules can be more reliably connected to each other. Therefore, the mounting state of each bus bar 12 with respect to the module main body 11 is stable, and the connecting posture of the module main body 11 connected by the plurality of bus bars 12 is more stable.

Next, the operation and effect of the battery stack 1 equipped with the above-mentioned bus bar module 10 will be described.
According to the bus bar module 10 of the present embodiment, there are two end modules 11A located at both ends of the module main body 11 and an intermediate module 11B located between the two end modules 11A. The end module 11A is composed of a unit module having the same configuration, and the one end module 11A1 and the other end module 11A2 are rotated by 180 degrees in a plan view, and the corresponding intermediate modules 11B are used. Since it is configured to be connected to, the types of unit modules can be reduced, and the manufacturing cost thereof can be reduced. Further, since the unit modules 11A and 11B can be easily increased or decreased, even if the number of battery modules 20, the number of thermistors 30 corresponding to the number of battery modules, the mounting position, etc. are changed according to the customer's request, the specifications can be easily changed. It is possible to respond to the specification change.

Further, according to the bus bar module 10 of the present embodiment, the module main body 11 is composed of a plurality of unit modules 11A and 11B, and when focusing on the adjacent unit modules, the module main body 11 engages with the adjacent unit modules. Since the joint portion 16 is provided only at the engagement portion forming position K on the side opposite to the side where the bus bar 12 connecting the adjacent unit modules is arranged, the plurality of unit modules 11A and 11B are connected to each other. The posture can be more stable. Therefore, even if the number of connected units 11A and 11B increases, it is possible to suppress a decrease in assembly workability. In addition, it is possible to prevent assembly mistakes and shorten the assembly work time.

In particular, since the engaging portion forming position K is provided only at the end on the side opposite to the side where the bus bar 12 connecting the adjacent unit modules is arranged, the assembling work is performed at the lowest possible cost. It is extremely excellent in suppressing deterioration of the property, preventing assembly mistakes, and shortening the assembly work time. That is, according to the bus bar module 10 of the present embodiment, the engaging portion 16 is not intentionally provided at the position of the end portion on the bus bar holding portion side where the connection posture is stabilized by mounting the bus bar 12.

Here, as shown in FIG. 7, when the bus bar module 10N of the comparative example is shown, if the bus bar module 10N does not have the engaging portion 16 in the module main body 11N, the connection effect is generated by mounting the bus bar 12, but it is shown in the figure. As described above, the bus bar 12 alone cannot restrain the bellows-shaped expansion / contraction state of the module body 11N in the longitudinal direction L.
Further, if the bus bar module 10N becomes long, the bus bar module 10N may be bent in the direction of the paper surface, and the connection portions with the unit modules 11A and 11B may be damaged or the connection portion of the harness may be disconnected. Therefore, when the module main body 11N does not have the engaging portion 16, there is room for improvement in suppressing the deterioration of the assembly workability.

On the other hand, according to the bus bar module 10 of the present embodiment, the posture stability when the bus bar 12 is mounted is taken into consideration, and the cooperative effect with the bus bar 12 mounted on the bus bar holding portion is minimized. The connecting posture can be stabilized only by forming the engaging portion 16 at a predetermined position. In other words, according to the bus bar module 10 of the present embodiment, the adjacent unit modules are connected to each other by an indirect connecting structure via the bus bar 12 on one end side and the engaging portion 16 on the other end side. Since it is connected by the direct connection structure, the connection posture can be stabilized and the deterioration of the assembly workability can be suppressed at the lowest possible cost. In addition, it is possible to prevent assembly mistakes and shorten the assembly work time. Further, the manufacturing cost of the module main body 11 can be reduced, and the man-hours for assembling the module main body 11 can be reduced.

Further, according to the bus bar module 10 of the present embodiment, the fitting concave portion 12d formed in each bus bar 12 and the fitting convex portion 11t formed on the bus bar holding portion side of the module main body 11 are fitted to each other. Therefore, the mounted state of each bus bar 12 is more stable, and the connected posture of the module main body 11 connected by the plurality of bus bars 12 is more stable. As a result, according to the bus bar module 10 of the present embodiment, the connected state of the module main body 11 is more reliably held by the cooperation between the mounted bus bar 12 and the engaging portion 16, so that the connection state can be maintained at the minimum cost. It is extremely excellent as a configuration for stabilizing the connection posture of the module main body 11.

The bus bar module according to the present invention is not limited to the above embodiment, and various modifications can be made without departing from the gist of the present invention.
For example, in the above embodiment, the battery stack 1 composed of a lithium ion secondary battery has been exemplified, but the present invention is not limited thereto. In addition to the lithium ion secondary battery, the battery stack 1 composed of other secondary batteries such as a nickel hydrogen battery can also be applied.

Further, the battery stack 1 according to the above-described embodiment is used as a power source for vehicles such as other electric vehicles, for example, railway vehicles such as hybrid trains, shared vehicles such as buses, freight vehicles such as trucks, and industrial vehicles such as battery-powered forklift trucks. It can also be used for equipment. Further, the battery stack 1 according to the above-described embodiment is applied to a battery pack constituting a power supply device other than an electric vehicle, such as an uninterruptible power supply used in a computer system or a server system, or a power supply device used in a private power generation facility. You may.
Further, in the above-described embodiment, the example in which the stack 1L on the high potential side and the stack 1R on the low potential side are connected in series has been described, but the stack 1L on the high potential side and the stack 1R on the low potential side are connected in parallel. Alternatively, a plurality of stacks 1L on the high potential side and stack 1R on the low potential side may be connected in series and in parallel.

Further, in the above-described embodiment, as the battery module 20, two circuits in which two battery cells 22 are connected in parallel are prepared, and these are connected in series to form a two-level, two-direct connection. However, the battery module 20 is not limited to the battery module 20. One battery cell may be used instead of one battery module 20.
For example, a general square battery or a cylindrical battery may be used, or a spacer may be used in which the positive and negative terminals of the laminated film type battery cell are projected from one side and the terminals are fixed. It is also possible to arrange a plurality of battery cells so that the terminals are aligned on one side and electrically connect them to the bus bar of the bus bar module.

1 Battery stack 2 Mounting surface 3 Positive terminal 4 Intermediate terminal 5 Negative terminal 6 SD switch 10 Busbar module 11 Module body 11A, 11B Unit module 12 Busbar 13 Sensor mountable area 14 Harness storage area 15 Cover 16 Engagement part 17 Engagement convex Part 18 Engagement recess 20 Battery module (battery body)
21 Case 22 Battery cell 30 Thermistor (temperature sensor)
31 Sensor body 32 Harness 33 Mounting part CL Lead center line K Engaging part formation position

Claims (2)

A busbar module attached to a battery stack composed of a plurality of battery bodies having a pair of positive and negative electrode terminals.
A module body including a bus bar holding portion for holding a bus bar connecting the electrode terminals of adjacent battery bodies is provided.
The module main body is composed of a plurality of unit modules connected in the arrangement direction of the plurality of battery bodies.
The two unit modules adjacent to each other in the arrangement direction have the bus bar attached to the bus bar holding portion so that the two adjacent unit modules are connected to each other by the bus bar on one end side in the direction orthogonal to the arrangement direction. The other end side opposite to the side where the bus bar holding portion is provided is a non-conducting portion that is not connected by the bus bar, and the non-conducting portion is an end portion outside the electrode terminal. An engaging portion is provided between the two adjacent unit modules to engage each other.
It has two end modules located at both ends of the module body and an intermediate module located between the two end modules.
The two end modules consist of unit modules of the same configuration, with one end module and the other end module being the corresponding intermediate modules when rotated 180 degrees relative to each other in plan view. A bus bar module characterized by being connected. The plurality of unit modules, the engaging portion, with provided only between the outer end portion than the electrode terminals in the non-conductive portion,
The fitting recess formed on the bus bar and the fitting protrusion formed on the side of the module body are formed so as to be fitted to each other.
The bus bar module according to claim 1, wherein the connected state of the module main body is held by the cooperation between the bus bar mounted on the bus bar holding portion and the engaging portion.

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