Energy storage device

Abstract

To provide an energy storage device that can suppress vibrations of electrical equipment components mounted on a circuit board. [Solution] In the battery case 12 of the battery 10, an upper case 14 and a lower case 16 are stacked vertically, and a reinforcement extending in the longitudinal direction in the vehicle width direction is joined to the bottom plate 30 of the lower case 16. The equipment bracket 50 has a base 54 attached to the upper surface of the reinforcement 40, a column 56 is erected from the base 54, and an equipment base 52 extends from the base 54 toward the front of the vehicle. As a result, the equipment base 52 on which the ECU 44 is mounted is attached to the side wall 32 on each side in the vehicle width direction, and the rear side is attached to the reinforcement 40 via the base 54, so that the equipment base 52 does not resonate even when the battery case 12 vibrates.

Description

Technical Field

[0001] The present invention relates to a power storage device.

Background Art

[0002] Patent Document 1 describes a power storage device in which a plurality of power storage stacks are arranged side by side in one direction and in a direction orthogonal to the one direction and housed in a case. The case includes a bottom wall, a top wall, and a peripheral wall that connects the peripheral edges of the bottom wall and the top wall to surround the power storage stack. Further, the case is provided with a protection structure for protecting the power storage stack against a load input in the vertical direction. In the protection structure, a load transmission member is disposed on the cross member. The load transmission member is capable of being compressed and deformed in the orthogonal direction, and the load transmission member is provided with a contact portion that contacts the power storage stack adjacent in the orthogonal direction in a compressed state.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] Generally, in a power storage device, electrical equipment components such as an ECU for controlling the operation of a battery pack in which power is stored are housed in a battery case together with the battery pack. Further, a substrate such as a pedestal for mounting the ECU or the like is disposed in the battery case, and the substrate is attached to each of the side walls whose both ends in one direction face each other.

[0005] By the way, the battery case is attached to the vehicle body and vibrates as the vehicle travels. For this reason, the substrate attached to the battery case also vibrates considerably. Further, since the substrate is attached to the opposing side walls, the amplitude of resonance with the vibration received from the battery case becomes large.

[0006] This invention has been made in view of the above facts, and aims to provide an energy storage device that can suppress vibrations in a circuit board on which electrical equipment components are attached. [Means for solving the problem]

[0007] To achieve the above objective, the first aspect of the present invention includes a case body formed by stacking a box-shaped upper case and a lower case, each having an opening on one side, with their openings facing each other and their opening peripheries joined, and housing a battery pack on which power is stored and electrical equipment components for controlling the operation of the battery pack inside; a reinforcement having a rectangular cross-sectional shape, with side walls erected from its periphery, and joined to the bottom plate of the lower case, with each of its longitudinal ends extending toward the side wall; and an equipment bracket having a base attached to the upper surface of the reinforcement, a column protruding upward from the base, and both ends along the longitudinal direction of the reinforcement attached toward the side wall, and a substrate on which the electrical equipment components can be mounted.

[0008] The first embodiment of the energy storage device includes a case body that houses a battery pack in which power is stored and electrical equipment components for controlling the operation of the battery pack, and the case body comprises an upper case and a lower case. The case body is formed by stacking an upper case and a lower case, each having an open side, with their openings facing each other, and joining the periphery of the opening of the upper case and the periphery of the opening of the lower case.

[0009] Furthermore, the lower case has side walls erected from the periphery of the bottom plate, and reinforcements are positioned there. The reinforcements have a rectangular cross-sectional shape and are joined to the bottom plate of the lower case, with each of their longitudinal ends extending toward the side walls.

[0010] Here, the reinforcement is equipped with equipment brackets on which electrical equipment components are attached. The equipment bracket comprises a base plate, a base, and a column. The base is attached to the upper surface of the reinforcement, and the column protrudes upward from the base plate. The base plate extends from the base plate in a direction intersecting the longitudinal direction of the reinforcement, and both ends of the base plate, along the longitudinal direction of the reinforcement, are attached to the side walls.

[0011] As a result, the circuit board on which electrical components are mounted is attached to the reinforcement via the base in addition to each of the side walls, thus suppressing resonant vibrations compared to the case where only the longitudinal ends of the reinforcement are attached to the side walls. Furthermore, the case body does not experience a decrease in load-bearing capacity against loads from above and below because the reinforcement and column are interposed between the lower case and the upper case.

[0012] In the second embodiment of the energy storage device, the equipment bracket is formed integrally with the base, column, and substrate.

[0013] In the energy storage device according to the second embodiment, the equipment bracket has a base, column, and circuit board that are integrally formed. This reduces the number of parts and makes assembly to the case body easier. [Effects of the Invention]

[0014] According to the present invention, the equipment bracket is provided with a substrate, a base, and a column portion on which electrical equipment components are mounted, and the base portion is attached to the reinforcement. As a result, in the present invention, the substrate on which the electrical equipment components are mounted is attached to the upper surface of the reinforcement via the base portion in addition to each of the side walls, so resonant vibrations can be suppressed compared to the case in which only both ends on the longitudinal side of the reinforcement are attached to the side walls. Furthermore, in the present invention, the reinforcement and the column portion of the equipment bracket are interposed between the lower case and the upper case, so that the load-bearing capacity of the case does not decrease against loads received from above and below. [Brief explanation of the drawing]

[0015] [Figure 1] This is a cross-sectional view showing the schematic configuration of the main parts of the battery according to this embodiment. [Figure 2] This is a plan view showing the schematic configuration of the main parts of the battery according to this embodiment. [Modes for carrying out the invention]

[0016] Embodiments of the present invention will be described in detail below with reference to the drawings. In this embodiment, a battery 10, which serves as an energy storage device mounted on a vehicle (not shown), will be described as an example. Battery 10 is, for example, a rechargeable secondary battery. Battery 10 is installed in a vehicle equipped with an electric motor as a power source for propulsion, and outputs DC power to drive the electric motor. The vehicle on which Battery 10 is installed may also be equipped with an engine as a power source for propulsion.

[0017] Such vehicles can include electric vehicles (BEV: Battery Electric Vehicle), hybrid vehicles (HEV: Hybrid Electric Vehicle), or plug-in hybrid vehicles (PHEV: Plug-in Hybrid Electric Vehicle). Furthermore, the battery 10 may be installed not only in vehicles as a driving device, but also in various devices that require high-voltage power.

[0018] FIG. 1 shows a schematic cross-sectional view of the main part of the battery 10 as viewed from the side of the vehicle, and FIG. 2 shows a schematic plan view of the main part of the battery 10. In the drawings, the upper side in the vertical direction is indicated by an arrow UP, one side in one direction intersecting the vertical direction is indicated by an arrow DA, and one side in the other direction intersecting the vertical direction and the one direction is indicated by an arrow DB. In the present embodiment, as an example, one direction is the longitudinal direction of the vehicle, the arrow DA is the front side of the vehicle, the other direction is the vehicle width direction, and the arrow DB is the right side in the vehicle width direction. Therefore, FIG. 1 is a cross-sectional view as viewed from the side of the vehicle showing the schematic of the main part of the battery 10, and FIG. 2 is a plan view showing the schematic of the main part of the battery 10.

[0019] As shown in FIGS. 1 and 2, the battery 10 includes a battery case 12 as a case body, and a general configuration in which the appearance is a substantially rectangular box shape (not shown) as a whole can be applied to the battery case 12. A floor panel (not shown) serving as a floor of the passenger compartment is disposed in the vehicle. The battery 10 is disposed with the battery case 12 below the floor panel at the rear side of the vehicle and is attached to a vehicle body not shown.

[0020] The battery case 12 includes an upper case 14 and a lower case 16, and the upper case 14 and the lower case 16 are each made of metal (for example, made of steel plate, aluminum die-cast, etc.).

[0021] The upper case 14 comprises a top plate 20, side walls 22, and flange portion 24, which are integrally formed. In the upper case 14, the side walls 22 project downward from the periphery of the top plate 20, which is roughly rectangular in plan view. The side walls 22 are formed around the entire periphery of the top plate 20, and the side walls 22 are inclined so that they widen outward as they move away from the top plate 20, at least on the vehicle front side. The flange portion 24 is formed by bending the tip (lower end) of the side wall 22 outward, and the flange portion 24 extends outward from the side wall 22 to the upper case 14 (outward in the vehicle longitudinal direction and outward in the vehicle width direction). As a result, the upper case 14 has a roughly box-like shape with a bottom that opens downward, and the flange portion 24 functions as the periphery of the opening.

[0022] The lower case 16 comprises a bottom plate 30, side walls 32, and flange portion 34, which are integrally formed. In the upper case 14, the side walls 32 project upward from the periphery of the bottom plate 30, which is roughly rectangular in plan view. The side walls 32 are formed around the entire periphery of the bottom plate 30, and are inclined so that they widen outward as they move away from the bottom plate 30, at least on the vehicle front side. The flange portion 34 is formed by bending the tip (upper end) of the side wall 32 outward, and the flange portion 34 extends outward from the side wall 32 to the lower case 16 (outward in the vehicle longitudinal direction and outward in the vehicle width direction). As a result, the lower case 16 has a roughly box-like shape with a bottom that opens upward, and the flange portion 34 functions as the periphery of the opening.

[0023] The battery case 12 has an upper case 14 and a lower case 16 facing each other vertically, with the flange portion 34 of the lower case 16 overlapped with the lower side of the flange portion 24 of the upper case 14. The battery case 12 is connected by nuts (both not shown in the figure) screwed onto bolts penetrating through each of the flange portions 24 and 34, fastening the flange portions 24 and 34, and connecting the upper case 14 and the lower case 16. In the battery case 12, a seal member not shown is interposed between the flange portion 24 and the flange portion 34, and the battery case 12 is tightly sealed (airtight and watertight) over the entire circumference by the seal member.

[0024] A battery pack not shown in the figure is used for the battery 10, and the battery pack is housed in the internal space of the battery case 12. The battery pack has a plurality (or even one) of battery modules (not shown in the figure) arranged longitudinally and transversely (in the vehicle front-rear direction and the vehicle width direction), and each battery module has a plurality of battery cells (not shown in the figure) stacked thereon. The battery pack enables input / output (charging and discharging) of DC power with a required voltage by connecting a plurality of battery modules in parallel or in series.

[0025] On the other hand, one or more reinforcements (reinforcement members) 40 are provided in the battery case 12 as reinforcement members, and the reinforcements 40 are arranged on the lower case 16.

[0026] The reinforcement 40 is elongated and has a substantially rectangular cross-section or a substantially hat-shaped cross-section. The reinforcement 40 has its longitudinal direction in the vehicle width direction and is arranged on the bottom plate 30 of the lower case 16 and joined to the bottom plate 30 using joining means such as welding. Also, both ends in the longitudinal direction of the reinforcement 40 are close to each of the side walls 32 on both sides in the vehicle width direction (each end may be joined to the side wall 32).

[0027] As a result, the battery case 12 has improved load-bearing capacity from below for the lower case 16, and also improved load-bearing capacity from both sides in the longitudinal direction of the reinforcement 40 for the lower case 16 and the upper case 14 joined to the lower case 16.

[0028] Furthermore, the reinforcement 40 can be provided with a resin tower section (not shown). The tower section can be joined to the upper surface of the reinforcement 40 (the surface on the upper case 14 side) and project upward from the reinforcement 40, with its upper end reaching (approaching) the inner surface of the top plate 20 of the upper case 14. This improves the load-bearing capacity of the battery case 12 against loads from above (loads received by the top plate 20 of the upper case 14).

[0029] In the battery 10, a reinforcement 40 is positioned between adjacent battery modules in one direction. This protects the battery modules in the battery case 12 from loads applied in both the vertical and non-vertical directions.

[0030] On the other hand, in the battery case 12, the space between one side wall 32 in one direction and the reinforcement 40 adjacent to the side wall 32 is designated as an equipment housing section 42, and the electrical equipment components of the battery 10 are housed in the equipment housing section 42.

[0031] In the vehicle, the battery pack of battery 10 is connected to an inverter (not shown), and the battery pack outputs power to the motor via the inverter (during discharge) and is charged by the power input via the inverter (during charging). In addition, the battery 10 is equipped with various sensors (not shown) on the battery pack, and the charging and discharging state of the battery pack (multiple battery modules) is controlled based on the information detected by the sensors.

[0032] The battery 10 is equipped with an ECU 44 and a junction box (JB) 46 as electrical components. The ECU 44 and junction box 46 are located within the equipment housing section 42 of the battery case 12. The ECU 44 is responsible for controlling the charging and discharging of the battery pack in the battery 10. The junction box 46 receives wiring from both the battery pack and the inverter, and is used internally for connecting the wiring from the battery pack to the inverter.

[0033] Furthermore, the battery case 12 has an equipment bracket 50 positioned within the equipment housing section 42 as a mounting section. In the battery case 12, there is no tower section on the reinforcement 40 adjacent to the equipment housing section 42, and the equipment bracket 50 is attached there.

[0034] The equipment bracket 50 comprises an equipment base 52 as a substrate, a base portion 54, and a column portion 56. Furthermore, the equipment bracket 50 is integrally formed by resin molding, with the equipment base 52, base portion 54, and column portion 56 being the same component.

[0035] The base portion 54 is in the shape of a roughly rectangular plate (it may also be in the shape of a strip), and its longitudinal direction is aligned with the longitudinal direction of the reinforcement 40. It is fixed to the upper surface of the reinforcement 40 by multiple fastening portions 58. Multiple fastening portions 58 are provided along the longitudinal direction of the base portion 54, and bolts 58A and nuts 58B are used for fastening portions 58. In the fastening portions 58, nuts 58B are screwed onto bolts 58A that are erected on the upper surface of the reinforcement 40 and pass through the base portion 54, thereby fastening and fixing them together.

[0036] The equipment bracket 50 has an equipment base 52 extending from a base 54 fixed to the reinforcement 40 into the equipment housing 42, and a column 56 erected above the base 54. The equipment bracket 50 also has a roughly strip-shaped head 56A formed at the upper end of the column 56. As a result, the equipment bracket 50 has a roughly L-shape when viewed in the vehicle width direction. Note that multiple column 56s may be erected from the base 54, and the head 56A may be formed to span across the upper ends of multiple column 56s.

[0037] The equipment base 52 is roughly flat, and the ECU 44 is mounted on its upper surface. In the battery case 12 (lower case 16), a junction box 46 is located below the equipment base 52. The junction box 46 is positioned on the bottom plate 30 of the lower case 16 in the equipment housing section 42 and is attached to the bottom plate 30. The junction box 46 is attached to the bottom plate 30 via a support frame (not shown).

[0038] The equipment base 52 is fixed to the reinforcement 40 at multiple points on the base 54 side (rear side of the vehicle) by fastening parts 58 (bolts 58A and nuts 58B). The equipment base 52 is also fixed to each of the side walls 32 on both sides in the vehicle width direction by fastening parts 60. The fastening part 60 uses, for example, a roughly L-shaped bracket (not shown) attached to the side wall 32, and a nut 60B is screwed onto a bolt 60A that passes through the equipment base 52 from the bracket, thereby fastening and fixing the equipment base 52 to the side wall 32 via the bracket.

[0039] As a result, in the equipment bracket 50, both sides of the equipment base 52 to which the ECU 44 is mounted in the vehicle width direction are fastened and fixed to the side wall 32, and the rear side of the vehicle is fastened and fixed to the reinforcement 40.

[0040] In the battery 10 configured in this way, the battery case 12 houses the battery pack along with the ECU 44 and junction box 46, etc. When the battery pack is connected to the inverter, the power from the battery pack is controlled and output by the ECU 44. In addition, when DC power of the required voltage is input to the battery 10 from the inverter, the battery pack is charged under the control of the ECU 44.

[0041] In the battery 10, the upper case 14 and the lower case 16 are joined together to form the battery case 12. In the battery case 12, a reinforcement 40 is positioned in the lower case 16. The reinforcement 40 is joined to the bottom plate 30, and its longitudinal direction extends in the vehicle width direction, with its tip close to (or joined to) each of the side walls 32. As a result, the load-bearing capacity of the battery case 12 is improved by the reinforcement 40 against loads input from the vehicle width direction.

[0042] Furthermore, the base 54 of the equipment bracket 50 is attached to the top surface of the reinforcement 40, and a column 56 is adjacent to this base 54 and extends upward. As a result, in the battery case 12, the reinforcement 40 and the column 56 are interposed between the top plate 20 of the upper case 14 and the bottom plate 30 of the lower case 16. This improves the load-bearing capacity of the battery case 12 against loads input from the vertical direction, thanks to the reinforcement 40 and the column 56.

[0043] On the other hand, the battery 10 has a battery case 12 attached to the vehicle body, and vibrations occur in the battery case 12 as the vehicle moves. An equipment base 52 is located inside the battery case 12, and the ECU 44 is mounted on this equipment base 52.

[0044] The equipment base 52 is generally attached to the side wall 32 on both sides in the vehicle width direction, and vibrations are transmitted to the equipment base 52 from the battery case 12. Therefore, if the equipment base 52 resonates with the battery case 12, the amplitude of the equipment base 52 increases, and the ECU 44 attached to the equipment base 52 also vibrates with a large amplitude. As a result, when the equipment base 52 resonates with the battery case 12, the ECU 44 is subjected to large acceleration and changes in acceleration, increasing the likelihood of malfunction.

[0045] Here, the equipment base 52 extends from the base 54 of the equipment bracket 50, and the base 54 of the equipment bracket 50 is attached to the reinforcement 40 at a plurality of fastening points 58. Therefore, the equipment base 52 is attached to the side wall 32 of the lower case 16 at a plurality of fastening points 60 on each side in the vehicle width direction, and one side (rear side) in the vehicle longitudinal direction is attached to the reinforcement 40 via the base 54. In other words, the equipment base 52 is attached to the lower case 16 at three points (three directions).

[0046] As a result, the resonant frequency of the equipment base 52 is higher compared to when it is fixed at only two points (two directions) on both sides in the vehicle width direction, and resonant vibration caused by vibrations of the battery case 12 is suppressed. Therefore, even if the battery case 12 vibrates, the battery 10 can suppress the ECU 44 and other components located inside the battery case 12 from being subjected to large accelerations and changes in acceleration, and can suppress malfunctions of the ECU 44 and other components even if the battery case 12 vibrates.

[0047] On the other hand, in the equipment bracket 50, the equipment base 52, the base portion 54, and the column portion 56 are integrally formed. Therefore, in the battery case 12, by attaching the equipment bracket 50 (base portion 54) to the upper surface of the reinforcement 40, not only is the vertical load-bearing capacity improved, but the equipment base 52 can also be attached to the reinforcement 40 to suppress resonant vibrations.

[0048] As a result, by using the equipment bracket 50 in the battery case 12, it is possible to reduce the number of assembled parts while suppressing a decrease in load-bearing capacity in the vertical direction and suppressing malfunctions of the ECU 44.

[0049] In the embodiment described above, an equipment bracket 50 in which the equipment base 52, base portion 54, and column portion 56 are formed by integral molding of resin was described as an example. However, in the equipment bracket, the column portion may be attached to a base portion which is integrally molded and provided on a substrate. [Explanation of symbols]

[0050] 10. Battery (energy storage device) 12 Battery Case (Case Body) 14 Upper Case 16 Lower Case 24, 34 Flange section (periphery of the opening) 30 Bottom plate 32 Side wall 40 Reinforce 42 Equipment housing section 44 ECU (Electrical Unit) 46 Junction Box 50 Equipment Brackets 52. Equipment base (circuit board) 54 Base 56 Column section 58, 60 Fastening parts

Claims

1. An upper case and a lower case, each having an open side, are stacked vertically with their openings facing each other and their opening edges joined together to form a case body that houses a battery pack for storing power and electrical equipment components for controlling the operation of the battery pack. The cross-sectional shape is rectangular and elongated, and the side walls are erected from the periphery and joined to the bottom plate of the lower case, and each of the ends in the longitudinal direction extends toward the side walls as a reinforcement, An equipment bracket comprising a base attached to the upper surface of the reinforcement, a column protruding upward from the base, and a substrate extending from the base in a direction intersecting the longitudinal direction of the reinforcement, with both ends along the longitudinal direction of the reinforcement each attached to the side wall, on which the electrical equipment components can be mounted and installed, Energy storage devices including

2. The energy storage device according to claim 1, wherein the equipment bracket is integrally formed with the base, the column, and the substrate.

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