JP6747275B2 - Battery pack - Google Patents

Description

The disclosure in this specification relates to a battery pack containing a battery.

Patent Document 1 discloses a vehicle battery pack including a battery case attached to the upper surface of a floor panel under a front seat. This battery case has a plurality of rectangular flat plate-shaped fixing portions for fixing the battery case to the floor panel with bolts or the like. The rectangular flat plate-shaped fixing portion is provided so as to project from the base portion of the lower case toward the vehicle door. The contents of the prior art documents listed as the prior art are incorporated by reference as explanations of the technical elements in this specification.

JP, 2014-24359, A

The battery pack for a vehicle as disclosed in Patent Document 1 becomes large in size when a large capacity of the battery is required, and the degree of freedom in mounting in the vehicle is reduced. If the degree of freedom in mounting is small, an excessive impact load may be applied to the battery pack at the time of a vehicle collision, which causes a problem that the battery is damaged.

In view of such a problem, an object of the disclosure in this specification is to provide a battery pack that can reduce an impact load on the battery.

The aspects disclosed in this specification employ different technical means to achieve their respective purposes. In addition, the reference numerals in parentheses in the claims and this section are examples showing the correspondence with specific means described in the embodiments described later as one aspect, and limit the technical scope. is not.

One of the disclosed battery packs is provided on a battery (21), a housing (11, 30) that houses the battery, and a base (30) of the housing, and is fixed to a vehicle-side member (19). The fixing portion (32) and a part of the base provided at a position projecting outward from the battery and the fixing portion, and configured to have a strength more easily deformed by an external force than a peripheral portion of the base. A fragile portion (36a; 136a; 236a, 336a),
Fragile portion, the depth dimension of the recess formed by the groove wall thickness than the portion of the periphery of the base is a thin walled portion.

According to this battery pack, the fragile portion, which is the thin-walled portion or the bent portion, is provided as a part of the base at a position projecting outward from the battery and the fixing portion. This makes it possible to positively damage or buckle the fragile portion when an external impact is applied to the base. By buckling the fragile portion at a position outside the battery and the fixed portion, it is possible to mitigate that an impact load applied to the battery pack is transmitted to the inside of the fragile portion. Therefore, it is possible to provide a battery pack that can reduce the impact load on the battery.
One of the disclosed battery packs is provided on a battery (21), a housing (11, 30) that houses the battery, and a base (30) of the housing, and is fixed to a vehicle-side member (19). The fixing part (32) and a part of the base provided at a position projecting outward from the battery and the fixing part, and configured to have a strength more easily deformed by an external force than a part around the base. A fragile portion (36a; 136a; 236a, 336a),
The fragile part is a thin part that is thinner than the surrounding part of the base, or a bent shape part whose cross-sectional shape is curved or bent, and the fragile part is outside the battery and the fixed part in the vehicle width direction. It is provided in a protruding position.

It is a perspective view which shows the battery pack of 1st Embodiment. It is a perspective view which shows the battery pack of the state which removed the cover of 1st Embodiment. It is a perspective view which shows the base in the battery pack of 1st Embodiment. It is a perspective view which shows the lower surface side of the base in the battery pack of 1st Embodiment. It is a bottom view which shows the positional relationship of the lower surface side and the vehicle side member about the battery pack of 1st Embodiment. FIG. 6 is a partial cross-sectional view taken along the line VI-VI in FIG. It is a partial bottom view of the base which showed the weakened part of 3rd Embodiment. It is a fragmentary sectional view of a base showing a weak part of a 3rd embodiment. It is a fragmentary sectional view of a base showing a weak part of a 4th embodiment.

Hereinafter, a plurality of modes for carrying out the present disclosure will be described with reference to the drawings. In each form, parts corresponding to the items described in the preceding form may be designated by the same reference numerals, and redundant description may be omitted. In the case where only a part of the configuration is described in each mode, the other modes described above can be applied to the other part of the configuration. Not only combinations of parts that clearly indicate that each form can be specifically combined, but also parts that are not explicitly specified may be combined unless there is a particular problem in the combination. It is possible.

(First embodiment)
The battery pack 1 of the first embodiment will be described with reference to FIGS. 1 to 6. In each drawing, a vertical direction or a height direction H1, a width direction W1, and a depth direction D1 are illustrated. In the battery pack 1 of this embodiment, the height direction H1 is set to the vertical direction as one of installation examples. The width direction W1 and the depth direction D1 are also the lateral direction orthogonal to the height direction H1.

The battery pack 1 can be applied to a vehicle equipped with a plurality of cells 21. An example of a vehicle is a vehicle. The battery pack 1 is mounted, for example, under the seat of a vehicle. The battery pack 1 is arranged in a space between a front seat and a floor, a rear seat and a floor of a vehicle, a space between a rear seat and a trunk room, a space between a driver's seat and a passenger seat, and the like. The vehicle is, for example, a hybrid vehicle that uses the battery pack 1 as a traveling drive source by combining an internal combustion engine and a battery-driven motor, an electric vehicle that is driven by a battery-driven motor, and the like. In this embodiment, an example in which the battery pack 1 is mounted on a hybrid vehicle will be described.

The battery pack 1 in this embodiment is installed, for example, so that the width direction W1 is the width direction of the vehicle. In this case, the width direction W1 corresponds to the collision load direction at the time of a side collision in which an impact is applied to the side portion of the vehicle from the outside.

As shown in FIG. 1, the battery pack 1 includes a cover 11 and a base 30. In the battery pack 1, a part of a housing having at least the cover 11 and the base 30 is fixed to the vehicle-side member 19. The cover 11 and the base 30 form an outer shell of the battery pack 1 and form a housing of the battery pack 1. The cover 11 and the base 30 are a pack case that accommodates each functional component. The cover 11 is made of resin. The cover 11 constitutes the outer shell of the upper part or the ceiling of the battery pack 1. The base 30 constitutes an outer shell of the lower part or the bottom of the battery pack 1.

FIG. 2 shows the battery pack 1 with the cover 11 removed. The battery pack 1 cooperates with a vehicle generator motor (MG) 15. The battery pack 1 provides a vehicle electric system. The generator motor 15 is connected to an internal combustion engine (EG) 16. The battery pack 1 is connected to an electric load (LD1) 17 and an electric load (LD2) 18 in the vehicle. The electric load 17 is an electric load such as a battery and a starter through which a large current flows. The electric load 18 is a part or all of a plurality of electric loads of the vehicle excluding the battery and the starter.

The generator motor 15 functions as a generator by being driven by the internal combustion engine 16. The battery pack 1 is charged by supplying at least a part of the electric power generated by the generator motor 15 to the battery pack 1. When the generator motor 15 is supplied with electric power from the battery pack 1, the generator motor 15 functions as an electric motor. The generator motor 15 functions as a power source together with the internal combustion engine 16. For example, the generator motor 15 supplies power that exceeds the power supplied by the internal combustion engine 16 or power that supplements the power supplied by the internal combustion engine 16.

The battery pack 1 includes a battery unit 20, a base 30, a bus bar unit 40, and an electric circuit 50. A battery unit 20, a bus bar unit 40, and an electric circuit 50 are mounted on the base 30. The electric circuit 50 is a functional component including a substrate 51 and a plurality of electrical components 52. The base 30 has a concave container portion 31 for installing the battery unit 20. The base 30 accommodates only a part (for example, the lower part) of the battery unit 20 in the container portion 31, and the remaining part (for example, the upper part) of the battery unit 20 projects from the base 30. The battery unit 20, the bus bar unit 40, and the electric circuit 50 are mounted on the base 30 along the height direction H1 which is an assembly direction. The battery unit 20, the bus bar unit 40, and the electric circuit 50 are fixed to the base 30 by a plurality of screws or fastening members such as bolts.

The battery pack 1 has a conductive connecting member 80 for electrically connecting the battery unit 20 and the electric circuit 50. The battery unit 20 has main terminals. The main terminal provides an intermittently controlled output line. The main terminal is the total plus terminal as the battery unit 20. The connection member 80 is a conductive member that connects the total plus terminal and the electric circuit 50.

In this embodiment, the connecting member 80 is provided by a bus bar which is a metal plate having a predetermined shape. The bus bar is manufactured by cutting a metal plate into a predetermined shape and bending it into a predetermined shape in the method for manufacturing the battery pack 1. The connection member 80 has a first bus bar connected to the battery unit 20 and a second bus bar connected to an electric circuit. The connection member 80 has a fixing member such as a bolt that tightens the first bus bar and the second bus bar.

The first bus bar is electrically connected to the total plus terminals of the plurality of unit cells 21 included in the battery unit 20 by being fixed by fixing means. The first bus bar has an opening for receiving the fixing member. The first bus bar has a shape protruding from the battery unit 20 toward the substrate 51 along the depth direction D1. The fixing member fastens the first bus bar along the height direction T1. The fixing member fastens the second bus bar along the height direction T1. The second bus bar wraps around the lower side of the substrate 51 from the tightened position and extends toward the substrate 51. The second bus bar has a plurality of terminals that penetrate the substrate 51. The second bus bar is electrically connected by being fixed to the electric circuit 50 by a fixing means. The fixing means is solder. The fixing means may be provided by various means such as welding and tightening with bolts. The second bus bar has a plurality of terminal portions for connecting to the electric circuit 50. The second bus bar has an opening for receiving the fixing member.

The battery unit 20 has a battery case 22 that houses a plurality of unit cells 21. The battery case 22 is made of electrically insulating resin. The battery case 22 is a part of a container that houses the plurality of unit cells 21. The battery case 22 fixes the plurality of unit cells 21 to each other. Further, the battery case 22 is also a fixing member that fixes the plurality of unit cells 21 to the base 30. The battery case 22 has a plurality of brackets for fixing the battery unit 20 to the base 30. The battery case 22 has a plurality of ribs in order to increase the strength of the wall and/or to reduce the gap between the battery case 22 and the base 30.

The battery unit 20 has a monitor module 23. The monitor module 23 has an electrically insulating resin member 24 and a monitor connecting member 25 connected to the plurality of unit cells 21. The monitor connecting member 25 is embedded in the resin member 24 by insert molding. The monitor connection member 25 passes through the resin member 24 to connect the unit cell 21 and the electric circuit 50. The monitor module 23 has a water sensor including a plurality of water detection electrodes. The monitor module 23 is arranged along one surface of the battery case 22, which is a hexahedron. The monitor module 23 is also a lid of the battery case 22.

The base 30 is made of a conductive metal. The base 30 is also called a carrier. The base 30 can be formed by aluminum-die casting, for example. The base 30 has high thermal conductivity and high rigidity. The base 30 includes a container portion 31 that receives the battery unit 20. The base 30 has a plurality of stays 32a, 32b, 32c, 32d. The plurality of stays 32a, 32b, 32c, 32d are collectively referred to as stay 32. The stay 32 is a fixing portion fixed to the vehicle-side member 19 for fixing the battery pack 1 to the vehicle. The vehicle-side member 19 is a part of the vehicle on which the battery pack 1 is mounted to fix the battery pack 1, and is, for example, a plate-shaped frame or panel. The stay 32 is provided with a mounting hole for inserting a bolt or the like, which is an example of a fixing means for fixing the stay 32 to the vehicle-side member 19. The stay 32 may be fixed to the vehicle-side member 19 by a fixing means such as welding.

As shown in FIGS. 5 and 6, the base 30, which is a part of the housing, includes a thin portion 36a provided at the widthwise end 36 at a position projecting outward from the unit cell 21 and the stay 32. .. The width direction end portion 36 is a portion of the base 30 that is located outside the container portion 31 and the heat dissipation wall 35, and is a portion on which the weak electric portion 52a of the substrate 51 is installed. The thin portion 36a is a fragile portion having a rigidity lower than that of the surroundings, which is formed by a groove portion having a rectangular cross section from the lower surface side of the base 30 facing the substrate 51. The thin portion 36a is composed of a plurality of groove portions provided in the widthwise end portion 36 so as to be arranged in a line over the entire length in the front-rear direction of the vehicle. With this configuration, the base 30 is provided with a fragile portion at the widthwise end portion 36 over the entire length in the front-rear direction of the vehicle, and an external force acts on the widthwise end portion over the entire length in the front-rear direction of the vehicle. 36 is easily broken.

The thin portion 36a is a portion formed by a groove portion that is recessed from the lower surface to the upper surface of the widthwise end portion 36 mounted on the substrate 51. The thin portion 36a is thinner than the surrounding portion by the depth dimension of the recess forming the groove portion. The thin portion 36a may be a portion formed by a groove portion that is recessed from the upper surface to the lower surface of the width direction end portion 36. The plurality of groove portions may be provided so as to be arranged in a plurality of rows arranged in the width direction W1 of the vehicle.

The widthwise end portion 36 is provided at the end portion of the battery pack 1 in the widthwise direction W1 of the vehicle. The width-direction end portion 36 is a plate-shaped portion located at a position near the side portion of the vehicle outer plate in the base 30. The width direction end portion 36 is provided in the base 30 so as to face the side portion of the vehicle outer shell, for example, the door portion. Therefore, when an impact is applied to the side portion of the vehicle, for example, when an object collides with the side portion of the vehicle, the side portion of the outer casing of the vehicle is recessed inward, so that the width direction end of the base 30 in the battery pack 1 is reduced. External force acts on the portion 36.

The thin portion 36a is a fragile portion configured to have a strength that is more likely to be deformed by an external force than a portion around the base 30. The thin portion 36 a constitutes a portion having a smaller thickness than the peripheral portion of the base 30, and corresponds to a portion of the width direction end portion 36 having low rigidity.

The thin portion 36 a is provided at a position projecting beyond the unit cell 21 in a direction intersecting with a direction in which the stay 32 b, which is a fixed part to the vehicle-side member 19, projects with respect to the unit cell 21. The thin portion 36a is provided at a position where the stay 32b protrudes toward the lateral side of the vehicle shell more than the unit cell 21 in the width direction W1 of the vehicle intersecting the front-rear direction of the vehicle where the stay 32b projects with respect to the unit cell 21. There is. The thin portion 36a is provided at a position projecting outward in the vehicle width direction W1 with respect to the unit cells 21 and the stays 32b, 32d, and is located closer to the vehicle side than the unit cells 21 and stays 32b, 32d. To do. The stays 32b and 32d are provided at positions projecting from the thin portion 36a in the front-rear direction of the vehicle. The thin portion 36a is provided at a position projecting in the vehicle width direction W1 from the vehicle side member 19 to which the stay 32b is fixed, and is located closer to the vehicle side portion than the vehicle side member 19.

The bus bar unit 40 provides a power path extending from the power terminal of the battery unit 20. The bus bar unit 40 has an electrically insulating resin member and a power connection member connected to the battery unit 20. The bus bar unit 40 is fixed on the base 30. The bus bar unit 40 has a power terminal 41, a power terminal 42, and a power terminal 43. The bus bar unit 40 has at least two power connection members. One power connection member is provided between one power terminal and the other power terminal of the battery unit 20 to provide an electrical connection. The outer power terminal 41 is connected to the generator motor 15. The power terminal 42 located inside the power terminal 41 is connected to the electric load 17. The power terminal 43 is connected to the electric load 18. The bus bar unit 40 is also a member that connects the plurality of power terminals 41, 42, 43, the battery unit 20, and the electric circuit 50.

The electric circuit 50 is fixed on the base 30. The electric circuit 50 is provided so as to spread beside the battery unit 20. The electric circuit 50 has a size and shape that spreads across one side of the battery unit 20 and across the other side of the battery unit 20. The battery unit 20 is installed in one corner of the base 30 having a substantially quadrilateral shape. The electric circuit 50 occupies a range extending over the base 30 in a key shape or an L shape that extends laterally of the battery unit 20. The electric circuit 50 is installed along the monitor module 23. A part of the electric circuit 50 is installed in a laterally extending range on the monitor module 23 side of the battery unit 20. The other part of the electric circuit 50 is installed beside the battery unit 20 so as to spread beside the peripheral surface of the monitor module 23.

The electric circuit 50 includes a substrate 51 and a plurality of electric components 52. The board 51 is a so-called printed board provided with a wiring pattern. The substrate 51 is a flat plate that can be called an L shape or a key shape. The substrate 51 extends over the horizontal range occupied by the electric circuit 50. The substrate 51 is installed on the heat dissipation wall 35 provided on the base 30. The substrate 51 and the heat dissipation wall 35 are in direct contact with each other so that heat can be transferred from the substrate 51 to the heat dissipation wall 35, or indirectly via a heat conductive member such as a sheet or gel having excellent heat conductivity. Are bonded in a state where they are in thermal contact with each other. The heat dissipation wall 35 and the stay 32 are integrally formed so that heat can be transferred through other parts of the base 30. Therefore, a heat radiation path is constructed in which the heat transferred from the substrate 51 to the heat radiation wall 35 is radiated to the vehicle-side member 19 through the stay 32.

The substrate 51 is a single substrate. A plurality of electric components 52 are arranged on the substrate 51. The substrate 51 has a plurality of connecting portions. Some or all of the plurality of connecting portions provide a connection between the power connecting member of the bus bar unit 40 and the electric component 52. The electric circuit 50 is connected to the plurality of unit cells 21. The plurality of electrical components 52 provide a controller. The control device monitors the voltage of each of the plurality of unit cells 21 included in the battery unit 20. The control device monitors the charge state and discharge state of each of the plurality of unit cells 21. The control device appropriately controls the state of charge of each of the plurality of unit cells 21. The unit cell 21 is, for example, a nickel hydrogen secondary battery, a lithium ion battery, or an organic radical battery.

The plurality of electric components 52 includes a single or a plurality of switch devices 53. The switch device 53 is a device that is on/off controlled by the electric circuit 50. The switch device 53 can intermittently control the output of the battery unit 20. The switch device 53 connects and disconnects the current supplied from the total plus terminal of the battery unit 20. The switch device 53 is mounted on the substrate 51. The switch device 53 is a semiconductor switch widely known as a transistor, a MOS, an IGBT, or the like. Further, the switch device 53 may be supported while being separated from the substrate 51. Further, the switch device 53 may be a mechanical relay that is opened and closed electromagnetically.

The connection member 80 electrically connects the total plus terminal and the switch device 53. The connection member 80 provides at least a part of the conductive member between the total positive terminal and the switch device. The connection member 80 is installed near the battery unit 20 on the substrate. The connection member 80 is installed on the edge of the substrate 51 closest to the battery unit 20. The connection member 80 is connected at a portion of the substrate 51 closest to the main terminals of the battery unit 20. The plurality of terminals for the connection member 80 are arranged on the substrate 51 along the battery unit 20. The switch device 53 is arranged near such a connecting member 80.

Water may get into the battery pack 1 when water is spilled on the seat, when an occupant wet with water uses the seat, or when the vehicle is soaked in water. In this case, the battery pack 1 may discharge using water as a discharge path. In this embodiment, a water sensor that detects water in the battery pack 1 and a control device that executes a countermeasure process when water is detected are provided. The control device monitors water ingress into the battery pack 1. The control device executes the countermeasure when the inundation is detected. The countermeasure process is, for example, turning off the breaker element, which is one of the plurality of electric components.

The control system provided by the electric circuit 50 provides a control device that is an electronic control unit (Electronic Control Unit). The control device has at least one arithmetic processing unit (CPU) and at least one memory device (MMR) as a storage medium for storing programs and data. The control device is provided by a microcomputer including a computer-readable storage medium. The storage medium is a non-transitional tangible storage medium that non-temporarily stores a computer-readable program. The storage medium can be provided by a semiconductor memory, a magnetic disk, or the like. The controller may be provided by a computer or a set of computer resources linked by a data communication device. The program, when executed by the control device, causes the control device to function as the device described in this specification, and causes the control device to function to execute the method described in this specification.

The control system has, as input devices, a plurality of signal sources that supply signals indicating information input to the control device. The control system acquires information by the control device storing the information in a memory device. The control system has a plurality of controlled objects, whose operations are controlled by the control device, as output devices. The control system controls the operation of the controlled object by converting the information stored in the memory device into a signal and supplying the signal to the controlled object.

The control device, the signal source, and the controlled object included in the control system provide various elements. At least some of these elements can be referred to as blocks for performing functions. In another aspect, at least some of those elements can be referred to as modules, or sections, that are interpreted as a configuration. Furthermore, the elements included in the control system can also be called means for realizing their functions only when they are intended.

The means and/or functions provided by the control system can be provided by software recorded in a substantial memory device and a computer executing the software, software only, hardware only, or a combination thereof. For example, if the controller is provided by an electronic circuit that is hardware, it can be provided by a digital circuit that includes multiple logic circuits, or an analog circuit. The electric circuit 50 may include a circuit as an inverter and/or a converter, and a monitor circuit for observing the voltages of the plurality of unit cells 21.

The battery unit 20 has a plurality of conductors that connect the plurality of unit cells 21 so that they can be energized. The plurality of conductors connect, for example, the plurality of unit cells 21 in series. The battery unit 20 has a plurality of monitor terminals. The monitor terminal is used to detect at least the voltage of the unit cell 21.

The monitor connection member 25 and the monitor terminal are electrically connected. The monitor module 23 and the water sensor are integrally provided by sharing the resin member 24. The monitor module 23 and the water sensor can be configured as one component.

FIG. 3 shows the base 30 with the electric circuit 50 such as the substrate 51 and the battery unit 20 removed. The base 30 has a plate shape or a dish shape. The base 30 has a shape called a shallow dish shape or a shallow cup shape. The shape of the base 30 is a downward convex shape and a concave shape from the top in the container portion 31. The base 30 has high rigidity against an external force that tends to bend it. The base 30 has high rigidity against an external force in the lateral direction in which the container portion 31 is opened, particularly in the width direction W1. The base 30 has high rigidity in the direction in which the plurality of unit cells 21 significantly swell.

The base 30 has a heat dissipation wall 35. On the heat dissipation wall 35, some electric components 52 are arranged via a substrate 51. Some of the electric components 52 are components that require heat dissipation. For example, the switch device 53 in the electric circuit 50 is arranged on the heat dissipation wall 35. An insulating sheet is installed between the heat dissipation wall 35 and the electric component 52 and between the heat dissipation wall 35 and the substrate. With this configuration, the heat of the electric component 52 moves to the heat dissipation wall 35 via the insulating sheet. In the base 30, the heat dissipation wall 35 is convex upward and concave from below. The heat dissipation wall 35 provides a concave heat dissipation portion from below on the lower surface of the base 30.

The substrate 51 installed on the base 30 includes a high-power part 52b in which an electric part 52 for controlling a current to the unit cell 21 is installed, and a low-power part 52b in which an electric part 52 in which a current smaller than that of the high-power part 52b flows is installed. And a portion 52a. The high voltage part 52b occupies an area where the switch device 53 is installed, for example. The light electric portion 52a occupies an area where, for example, the switch device 53 does not exist, and the electric component 52 for outputting and inputting an electric signal is installed. The portion of the substrate 51, which is located on the opposite side of the thin portion 36a in the vehicle width direction W1 from the unit cell 21, is the high-power portion 52b. The portion above the thin portion 36a is the weak electric portion 52a. Therefore, the plurality of switch devices 53 are not installed in the portion of the substrate 51 located above the thin portion 36a, and are not provided in all of the portions located on the side opposite to the thin portion 36a in the vehicle width direction W1. is set up.

The container part 31 is formed to have at least a side wall 31a, a side wall 31b, a bottom wall 31c, a back wall 31d, and a front wall 31e. The container part 31 is an open container for installing the battery unit 20 and having an opening facing upward.

The side wall 31a and the side wall 31b are provided on both sides of the container portion 31 in the width direction W1. The side wall 31a and the side wall 31b are provided so as to face each other in the stacking direction of the plurality of unit cells 21, that is, in the width direction W1. The inner surface of the side wall 31 a and the inner surface of the side wall 31 b face the inside of the container portion 31. The inner surface of the side wall 31a and the inner surface of the side wall 31b are surfaces facing the battery unit 20 in the width direction W1 with a minute gap therebetween or in contact with the battery unit 20.

The side wall 31a has a plurality of bolt holes for fixing the battery case 22. The side wall 31b has a plurality of bolt holes for fixing the battery case 22. These bolt holes have a hole having a depth in the height direction H1 which is an assembly direction, and a female screw formed on the inner surface of the hole. The side wall 31a and the side wall 31b are also formed with other bolt holes for fixing the cover 11 and other bolt holes for fixing components for electrical connection.

The bottom wall 31c forms the bottom of the container portion 31. The bottom wall 31c is a wall that connects the lower end of the side wall 31a and the lower end of the side wall 31b. The inner surface of the bottom wall 31c faces the inside of the container portion 31. The inner surface of the bottom wall 31c faces upward as the upper surface of the base 30, and faces the bottom surface of the battery unit 20. The back wall 31d is located behind the container portion 31. The back wall 31d is a wall that connects the side wall 31a, the side wall 31b, and the bottom wall 31c. The inner surface of the back wall 31d faces the inside of the container portion 31, and faces the surface of the battery unit 20 opposite to the monitor module 23. The back wall 31d connects the upper part of the side wall 31a and the upper part of the side wall 31b. The back wall 31d connects the side wall 31a and the side wall 31b in a straight line. The back wall 31d provides a beam provided between the side wall 31a and the side wall 31b. The back wall 31d opposes an external force that spreads the side wall 31a and the side wall 31b outward and spreads them outward.

The front wall 31e is located at the front of the container portion 31. The front wall 31e is a wall that is connected to the bottom wall 31c, and is a wall that stands upright from the bottom wall 31c. The front wall 31e may be a wall that connects the side wall 31a, the side wall 31b, and the bottom wall 31c. The front wall 31e faces the inside of the container portion 31 and faces the monitor module 23 in the battery unit 20. The front wall 31e is a part of the staircase wall formed between the bottom wall 31c and the heat dissipation wall 35. The front wall 31e connects the side wall 31a and the side wall 31b. The front wall 31e provides a beam provided between the side wall 31a and the side wall 31b. The front wall 31e opposes an external force that causes the side wall 31a and the side wall 31b to spread upward and fall outward.

Each of the plurality of bus bars 45, 46 and 47 has a portion extending along the battery unit 20. The plurality of bus bars 45, 46, 47 extend in parallel. The plurality of bus bars 45, 46, and 47 are distributed on both sides of the heat dissipation wall 35. With such an arrangement, it is possible to provide the battery pack 1 suitable for connection with the electric component 52 installed on the heat dissipation wall 35. This arrangement can contribute to, for example, shortening the current path through which a relatively large current is interrupted by the switch device 53. Therefore, it is possible to contribute to suppressing the heat generation itself of the electric circuit 50 by shortening the current path while promoting the heat dissipation of the plurality of electric components 52 by the heat dissipation wall 35.

The connection member 80 is installed between the battery unit 20 and the heat dissipation wall 35. The connection member 80, which is also a part of the bus bar unit 40, is adjacent to the heat dissipation wall 35. Therefore, also for the connection member 80, it is possible to form a heat dissipation path that transfers heat to the heat dissipation wall 35, which can contribute to suppressing heat generation of the electric circuit 50.

The battery unit 20 is mounted on the base 30. The battery case 22 is fixed to the base 30 by a plurality of bolts 71. The plurality of bolts 71 are inserted into bolt holes provided in the base 30. The plurality of bolts 71 tighten the bracket provided on the battery case 22 toward the base 30. The plurality of bolts 71 function as fastening members.

Next, effects obtained by the battery pack 1 of the first embodiment will be described. The battery pack 1 includes a plurality of unit cells 21, a housing that houses the unit cells 21, a stay 32 that is provided on a base 30 that is a part of the housing and is fixed to the vehicle-side member 19, and a base 30. And a thin portion 36a that is a part. The thin portion 36a is provided at a position projecting outward from the unit cell 21 and the stay 32, and is a fragile portion configured to have a strength more easily deformed by an external force than a portion around the base 30.

The battery pack 1 has a fragile portion, which is a thin portion 36a, as a part of the base 30 at a position projecting outward from the unit cell 21 and the stay 32. This allows the thin portion 36a to be positively deformed, damaged, or buckled when an external impact is applied to the base 30. By buckling the thin portion 36a at a position outside the unit cell 21 and the stay 32, the thin portion 36a functions as a cushion for absorbing impact, and the load applied to the battery pack 1 is less than that of the thin portion 36a. Can also be transmitted to the inside. Therefore, according to the battery pack 1, it is possible to reduce the impact load and stress applied to the unit cell 21 due to, for example, a collision or the like, and protect the unit cell 21.

The thin portion 36 a is provided at a position projecting from the unit cell 21 in a direction intersecting with a direction in which the stay 32 projects with respect to the unit cell 21. With this configuration, when an external force acts on the battery pack 1 in the intersecting direction, the thin portion 36a can be deformed, damaged, buckled, etc. by the external force before the stay 32. The external force acting on the stay 32 can be reduced by the effect of absorbing the external force due to the buckling of the thin portion 36a, and the damage to the stay 32 can be suppressed. Therefore, according to the battery pack 1, by suppressing the damage of the stay 32, the fixing function with the vehicle-side member 19 can be protected, and the battery pack 1 can be largely moved to damage the unit cell 21 or the high-power portion 52b. Can be suppressed.

The thin portion 36a is provided at a position projecting outward with respect to the width direction W1 of the vehicle with respect to the unit cell 21 and the stay 32. According to this configuration, for example, when an external force acts on the side portion of the vehicle due to a side collision of the vehicle or the like, first, the thin portion 36 can be deformed, damaged, buckled, or the like by the external force. Since the external force acting on the stay 32 can be reduced by the external force absorbing effect due to the buckling of the thin portion 36a in the case of a side collision of the vehicle, the damage to the stay 32 can be suppressed. Therefore, according to the battery pack 1, the function of fixing the stay 32 to the vehicle-side member 19 can be protected by suppressing damage to the stay 32 in the event of a side collision of the vehicle, etc. It is possible to prevent the high-voltage portion 52b from being damaged.

The stay 32 is located at a position projecting from the thin portion 36a in the front-rear direction of the vehicle. The thin portion 36a is provided at a position projecting in the vehicle width direction W1 from the vehicle-side member 19 to which the stay 32 is fixed. According to this configuration, since the thin portion 36a is provided at a position projecting in the vehicle width direction W1 with respect to the vehicle side member 19, for example, when an external force acts on the vehicle side portion due to a vehicle side collision or the like. Moreover, the vehicle side member 19 and the stay 32 can be protected by the buckling of the thin portion 36a. Therefore, according to the battery pack 1, since the external force can be more reliably and first absorbed by the thin portion 36a, the fixing function of the battery pack 1 and the vehicle-side member 19 can be protected.

A portion of the substrate 51 installed on the base 30 that is located on the opposite side of the thin portion 36a in the vehicle width direction W1 is a high-power portion on which an electric component 52 that controls a current to the unit cell 21 is installed. It corresponds to 52b. The portion of the substrate 51 located above the thin portion 36a corresponds to the weak electric portion 52a in which the electric component 52 through which a smaller current than the strong electric portion 52b flows is installed. According to this configuration, when an external force acts on the side portion of the vehicle due to, for example, a side collision of the vehicle, the weak electric portion 52a is damaged along with the buckling of the thin portion 36a, but instead, the high electric portion 52b is used. Can be protected. As a result, it is possible to provide the battery pack 1 with improved safety, which can protect the high-power portion 52b through which a large current flows.

The plurality of switch devices 53 that control the current to the unit cell 21 are not installed in the portion of the substrate 51 located above the thin portion 36a, and are located on the side opposite to the thin portion 36a in the vehicle width direction W1. All are installed in the part located in. According to this configuration, the thin portion 36a buckles or the like at a position outside the high-voltage portion 52b, so that the thin portion 36a functions as a cushion that absorbs an impact, and the impact load applied to the battery pack 1 is reduced. It is possible to mitigate the transmission to the high voltage part 52b. Therefore, according to the battery pack 1, even if an external force acts, for example, due to a collision or the like, the strong current part 52b through which a large current flows can be protected more preferentially than the weak current part 52a, so that the battery pack 1 with improved safety is provided. it can.

(Second embodiment)
In the second embodiment, a thin portion 136a which is another form of the thin portion 36a which is the fragile portion of the first embodiment will be described with reference to FIG. The battery pack 1 of the second embodiment has the same components as the first embodiment except for the thin portion 136a, and has the same effects. The contents different from the first embodiment will be described below.

As shown in FIG. 7, the thin portion 136a is provided at the widthwise end portion 36 of the base 30 over the entire length in the front-rear direction of the vehicle. That is, the thin portion 136a is configured by one groove portion that extends over the entire length in the front-rear direction of the vehicle at the width direction end portion 36, and has a wall thickness dimension smaller than the surrounding wall thickness dimension at the width direction end portion 36. ing. The thin portion 136a is a fragile portion that is formed by a groove portion that is recessed in a strip shape from the lower surface side of the base 30 that faces the vehicle-side member 19 and that has a rigidity lower than that of the surroundings.

According to the second embodiment, it is possible to provide the housing in which the width direction end portion 36 is more easily broken than the thin portion 36a due to an impact from the outside, and is easily buckled. By buckling the widthwise end portion 36 so as to be bent over the entire length in the front-rear direction of the vehicle, it is possible to reduce the impact transmitted to the container portion 31 and protect the unit cell 21. Further, since the weak electric portion 52a installed on the width direction end portion 36 is easily broken, the weak electric portion 52a is damaged, so that the battery pack 1 capable of protecting the strong electric portion 52b through which a large current flows can be provided.

(Third Embodiment)
In the third embodiment, a thin portion 236a which is another form of the thin portion 36a which is the fragile portion of the first embodiment will be described with reference to FIG. The battery pack 1 of the third embodiment has the same components as the first embodiment except for the thin portion 236a, and has the same effects. The contents different from the first embodiment will be described below.

As shown in FIG. 8, the thin portion 236a is a fragile portion having a rigidity lower than that of the surroundings, which is constituted by a groove portion having a wedge-shaped cross section from the upper surface side of the base 30 facing the substrate 51. The thin portion 236a is configured by a groove portion that is recessed in a wedge shape, and has a wall thickness dimension smaller than the wall thickness dimension around the width-direction end portion 36. The thin portion 236a is composed of a plurality of groove portions provided so as to be scattered at the widthwise end portion 36 over the entire length in the front-rear direction of the vehicle.

The thin portion 236a may be constituted by a groove portion having a wedge-shaped cross section from the lower surface side of the base 30 facing the vehicle-side member 19. Further, the thin portion 236a may be configured by one groove portion provided in the widthwise end portion 36 of the base 30 over the entire length in the front-rear direction of the vehicle, like the thin portion 136a of the second embodiment.

(Fourth Embodiment)
In the fourth embodiment, a bent portion 336a which is another form of the thin portion 36a which is the weak portion of the first embodiment will be described with reference to FIG. The battery pack 1 of the fourth embodiment has the same components as the first embodiment except for the bent portion 336a, and has the same effects. The contents different from the first embodiment will be described below.

As shown in FIG. 9, the curved shape portion 336a is a portion whose cross-sectional shape is curved or bent. The width direction end portion 36 of the fourth embodiment has a cross-sectional shape in which the tip portion intersects a portion inside the bent shape portion 336a, that is, a portion on the high-electricity portion 52b side. Therefore, the width-direction end portion 36 has a shape in which the tip end portion is curved so as to be curved or bent toward the vehicle-side member 19 side with the curved shape portion 336a as an intersection. The bent portion 336a is a fragile portion having lower rigidity than the surroundings. The bent-shaped portion 336a is a bent portion that bends or a curved portion that has a curved cross-sectional shape. Further, the curved portion 336a may be continuously provided at the widthwise end portion 36 of the base 30 over the entire length in the front-rear direction of the vehicle, like the thin portion 136a of the second embodiment.

According to this configuration, when an external impact is applied to the width direction end portion 36, the tip end portion of the width direction end portion 36 is deformed so as to be further bent with the curved shape portion 336a as a base point. By this deformation, it is possible to mitigate that the impact load applied to the battery pack 1 is transmitted to the inside of the curved shape portion 336a. Therefore, it is possible to provide the battery pack 1 that can reduce the impact load on the unit cell 21.

(Other embodiments)
The disclosure of this specification is not limited to the illustrated embodiments. The disclosure encompasses the illustrated embodiments and variations on them based on them. For example, the disclosure is not limited to the combination of parts and elements shown in the embodiments, and various modifications can be implemented. The disclosure can be implemented in various combinations. The disclosure may have additional parts that may be added to the embodiments. The disclosure includes parts and elements of the embodiments omitted. The disclosure includes replacements or combinations of parts, elements between one embodiment and another. The disclosed technical scope is not limited to the description of the embodiments. The disclosed technical scope is shown by the description of the claims, and should be understood to include meanings equivalent to the description of the claims and all modifications within the scope.

In the above-described embodiment, the electric circuit 50 includes the plurality of switch devices 53. Alternatively, the electric circuit 50 may include a single switch device 53. Further, the electric circuit 50 may include a switch array in which a plurality of switch devices 53 are housed in a circuit package. The switch array may be mounted on the substrate 51 or may be supported separately from the substrate 51.

In the above-described embodiment, the unit cell 21 constituting the battery unit 20 may have, for example, a thin flat plate-shaped outer case, and the outer case may be formed of a laminate sheet. The laminate sheet is made of a highly insulating material. The unit cell 21 has, for example, an internal space of a flat container that is hermetically sealed by sealing the ends of the folded laminate sheet by heat-sealing the ends. A battery main body including an electrode assembly, an electrolyte, a terminal connecting part, a part of the positive electrode terminal part, and a part of the negative electrode terminal part is built in this internal space. Therefore, in the plurality of unit cells 21, the battery main body is housed in a sealed state inside the flat container by sealing the peripheral portion of the flat container. Each unit cell 21 has a pair of electrode terminals drawn outward from the flat container.

As the unit cell 21 that constitutes the battery unit 20 in the above-described embodiment, for example, a unit cell having a columnar outer shape may be used.

In the above-described embodiment, the plurality of unit cells 21 forming the battery unit 20 may be installed in a state of being in contact with each other without providing a gap between adjacent unit cells, or a predetermined gap between the unit cells. You may make it open and install.

11... Cover (casing), 19... Vehicle side member, 21... Single battery (battery)
30... Base (housing), 32... Stay (fixed part)
36a, 136a, 236a... Thin portion (fragile portion)
51... Substrate, 52a... Weak electric part, 52b... Strong electric part,
53...Switch device, 336a...Bent-shaped part (fragile part)

Claims (7)

A battery (21),
A casing (11, 30) for accommodating the battery,
A fixing portion (32) provided on the base (30) of the housing and fixed to the vehicle-side member (19);
A fragile portion that is a part of the base provided at a position projecting outward from the battery and the fixing portion, and has a strength that is more likely to be deformed by an external force than a peripheral portion of the base ( 36a; 136a; 236a ) ,
Equipped with
The fragile portion has a depth dimension of the recess formed by the groove, the base of the battery pack is thicker than a portion of the periphery is thin walled portion. A battery (21),
A casing (11, 30) for accommodating the battery,
A fixing portion (32) provided on the base (30) of the housing and fixed to the vehicle-side member (19);
A fragile portion that is a part of the base provided at a position projecting outward from the battery and the fixing portion, and has a strength that is more likely to be deformed by an external force than a peripheral portion of the base ( 36a; 136a; 236a, 336a),
Equipped with
The fragile portion is a thin-walled portion having a thinner wall thickness than the peripheral portion of the base, or a bent portion having a curved or bent cross-sectional shape,
The fragile portion, the battery and the fixed portion have that batteries pack provided at a position projecting outward in the width direction of the vehicle than. The fixing portion is located at a position projecting more than the fragile portion in the front-back direction of the vehicle,
The fragile portion is a battery pack according to claim 2 which is provided at a position out collision in the width direction of the vehicle than the vehicle-side member to which the fixing portion is fixed. On the base Ri Contact is placed substrate (51) is,
A portion of the substrate located on the side opposite to the weak portion in the vehicle width direction corresponds to a high-power portion (52b) on which an electric component that controls the current to the battery is installed, and is located on the weak portion. portions located the battery pack according to claim 3 you corresponds to the strong electric weak electric unit electrical component is installed through which current smaller than the portion (52a) to. A substrate (51) is installed on the base,
The plurality of switch devices (53) for controlling the electric current to the battery are not installed in a portion of the substrate located above the fragile portion, and are arranged on the side opposite to the fragile portion in the vehicle width direction. the battery pack of claim 4 all portions located that are installed. The fragile portion is a battery pack as claimed in any one of the preceding claims 2 are provided, et al is over the length of the longitudinal direction of the vehicle in the base. The fragile portion is according to any one of claims 1 to 6 provided in protruding position than the battery in a direction of the fixing portion intersecting the direction of projecting to the battery Battery pack.

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