Energy Storage Unit

Abstract

To further miniaturize a size a power storage unit.SOLUTION: A power storage unit comprises: a resin holder that houses a part of a power storage element in a state where it is exposed to an upper side; a circuit board that contains wiring electrically connected to the power storage element, and is fixed to a lower side of the holder; and a metal case that houses the power storage element and the holder by fixing an open end opened to the lower side to the circuit board. The holder contains one or a plurality of column parts projected to the upper side from the power storage element.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] The present disclosure relates to an electricity storage unit. [Background technology]

[0002] There is known an energy storage unit that houses a plurality of energy storage elements. The energy storage unit is used, for example, as an auxiliary power source that supplies power to on-board electrical equipment when an abnormality occurs in the vehicle battery. For example, Patent Document 1 discloses an energy storage unit that includes a plurality of energy storage devices (electric double layer capacitors) held by a holder.

[0003] Furthermore, Patent Document 2 discloses a configuration in which a metallic shield case that covers both sides of a circuit board is electrically connected to a ground line (a line connected to a ground potential) of the circuit board. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2016-81795 A [Patent Document 2] JP 2020-114112 A Summary of the Invention [Problem to be solved by the invention]

[0005] There is a demand for miniaturization of the energy storage unit. For example, Patent Document 1 discloses that, whereas conventionally, multiple energy storage devices are held vertically by an upper holder and a lower holder, multiple energy storage devices are cantilevered only by the lower holder (the holder in Patent Document 1), thereby making the energy storage unit lower in height. In Patent Document 1, the energy storage devices are held by a pair of holding parts provided on the holder.

[0006] The present disclosure aims to further reduce the size of the power storage unit. [Means for solving the problem]

[0007] The energy storage unit of the present disclosure is an energy storage unit comprising: a resin holder that houses an energy storage element with a portion of the energy storage element exposed on the upward side; a circuit board that includes wiring electrically connecting to the energy storage element and is fixed to the underside of the holder; and a metal case that houses the energy storage element and the holder by fixing the open end that is open on the downward side to the circuit board, wherein the holder includes one or more pillar portions that protrude upward beyond the energy storage element. Effect of the Invention

[0008] According to the present disclosure, the power storage unit can be made smaller. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is a perspective view of an electricity storage unit according to an embodiment. [Diagram 2] FIG. 2 is an exploded perspective view of the electricity storage unit shown in FIG. [Diagram 3] FIG. 3 is a cross-sectional view of the electricity storage unit taken along the line indicated by the arrow III in FIG. [Figure 4] FIG. 4 is an exploded cross-sectional view of the electricity storage unit shown in FIG. [Diagram 5] FIG. 5 is an exploded perspective view of the board unit according to the embodiment. [Figure 6] FIG. 6 is a plan view of the board unit according to the embodiment. [Figure 7] FIG. 7 is a perspective view showing a part of the holder according to the embodiment. [Figure 8] FIG. 8 is a plan view showing a part of the holder according to the embodiment. [Figure 9] FIG. 9 is a cross-sectional view showing a part of the electricity storage unit according to the embodiment. [Figure 10] FIG. 10 is a cross-sectional view showing a part of an electricity storage unit according to a modified example. [Figure 11]FIG. 11 is a plan view of a portion of a substrate unit according to a modified example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] [Description of the embodiments of the present disclosure] The gist of the present disclosure includes the following configurations.

[0011] (1) The energy storage unit disclosed herein includes a resin holder that houses an energy storage element with a portion of the energy storage element exposed on an upward side, a circuit board that includes wiring electrically connecting to the energy storage element and is fixed to the underside of the holder, and a metal case that houses the energy storage element and the holder by fixing the open end that is open on the downward side to the circuit board, wherein the holder includes one or more pillar portions that protrude upward beyond the energy storage element.

[0012] When the case bends downward due to vehicle vibration or the like, the pillars come into contact with the case, thereby suppressing the bending of the case. This makes it possible to suppress a short circuit between the case and the energy storage element caused by the bent case coming close to the energy storage element in the vertical direction. According to the energy storage unit of the present disclosure, the inclusion of the pillars eliminates the need to design the gap between the case and the energy storage element to be extra large in consideration of the bending of the case in order to suppress a short circuit. In other words, the gap between the case and the energy storage element can be made smaller. This allows the energy storage unit to be made smaller.

[0013] (2) The case may include an opposing wall that faces the storage element and the holder in the vertical direction, and one or more of the pillar portions may come into contact with the opposing wall before the storage element when the opposing wall bends downward.

[0014] With this configuration, a gap can be maintained between the opposing wall and the energy storage element, thereby preventing the energy storage element from shorting out with the opposing wall.

[0015] (3) The wiring may include a ground line, and the open end may be electrically connected to the ground line, and the one or more pillar portions may face the opposing wall with a gap in the vertical direction when the opposing wall is not deflected.

[0016] With this configuration, the effect of the tolerance of the pillars can be absorbed by the gap, so that the case can be prevented from floating up and down from the circuit board. Also, by providing the gap, the pillars do not come into contact with the opposing wall when the opposing wall bends in small increments, and the pillars come into contact with the opposing wall only when the opposing wall bends so greatly that there is a risk of short-circuiting with the storage element. This reduces the load on the fastening portion between the case and the circuit board.

[0017] (4) The one or more pillar portions may include at least one of a first pillar portion protruding upward from a corner of the holder and a second pillar portion protruding upward from a side of the holder.

[0018] By providing pillars at the corners or sides of the holder, a bent case can be supported and the pillars can increase the rigidity of the outer frame of the holder, thereby suppressing the holder from bending, thereby suppressing a short circuit caused by the storage element held by the holder coming close to the case when the holder bends.

[0019] (5) The storage elements may be arranged in a plurality of rows in an arrangement direction intersecting the vertical direction, and the holder may include a plurality of recesses each accommodating a corresponding one of the storage elements, a frame portion partitioning two of the plurality of recesses adjacent to each other in the arrangement direction, and a holding portion protruding upward from the frame portion and holding the storage elements by abutting the storage elements accommodated in the recesses in the arrangement direction, and the one or more pillar portions may include a third pillar portion protruding upward from the holding portion.

[0020] The third column section is provided in the holding section, and therefore can face the central region of the opposing wall in the vertical direction and can support the portion of the opposing wall that is subject to large deflection, thereby more reliably preventing a short circuit between the energy storage element and the opposing wall.

[0021] [Details of the embodiment of the present disclosure] Hereinafter, the details of the embodiments of the present disclosure will be described with reference to the drawings.

[0022] <1. Overall configuration of the power storage unit 10> FIG. 1 is a perspective view of an electricity storage unit 10 according to the embodiment. FIG. 2 is an exploded perspective view of the electricity storage unit 10 shown in FIG. FIG. 3 is a cross-sectional view of the electricity storage unit 10 taken along the line indicated by the arrow III in FIG. FIG. 4 is an exploded cross-sectional view of the electricity storage unit 10 shown in FIG.

[0023] The power storage unit 10 is an auxiliary power source (backup power source) that is mounted on, for example, a vehicle and that, in the event of an abnormality such as a voltage drop in the vehicle battery, supplementarily supplies power to various parts in the vehicle that are normally supplied with power by the battery. The power storage unit 10 may supply power to on-board electrical equipment such as lamps, or may supply power to an actuator that controls the vehicle's shift lever, etc.

[0024] 2, the power storage unit 10 includes a substrate unit 20, a shield unit 30, and a cover unit 40. The substrate unit 20 is housed in the shield unit 30, and the shield unit 30 is housed in the cover unit 40. That is, in the power storage unit, the substrate unit 20 is located at the innermost position, and the cover unit 40 is located at the outermost position.

[0025] 2. Configuration of Board Unit 20 FIG. 5 is an exploded perspective view of the board unit 20. As shown in FIG. FIG. 6 is a plan view of the board unit 20. As shown in FIG.

[0026] The board unit 20 includes a plurality of energy storage elements 50, a holder 60, and a circuit board 70. In this embodiment, eight energy storage elements 50 are arranged in the arrangement direction, but the number of energy storage elements 50 is not particularly limited. The holder 60 holds the plurality of energy storage elements 50 in a state where they are exposed on the upper side in a direction intersecting the arrangement direction (hereinafter referred to as the "vertical direction"). The circuit board 70 is fixed to the lower side of the holder 60 in the vertical direction.

[0027] A direction intersecting both the arrangement direction and the vertical direction is referred to as a "width direction". In this embodiment, the arrangement direction, the vertical direction, and the width direction are each perpendicular to each other. However, these directions may be oblique and may not be perpendicular to each other. In each drawing, the arrangement direction is indicated by an arrow x, the width direction by an arrow y, and the vertical direction by an arrow z. In the arrangement direction and the width direction, the side indicated by the arrow is referred to as "one side", and the opposite side is referred to as "the other side". In the vertical direction, the side indicated by the arrow is referred to as "upper side", and the opposite side is referred to as "lower side". The vertical direction in each drawing is a direction for convenience, and may not coincide with the vertical direction (gravity direction) when the storage unit 10 is installed.

[0028] In FIG. 5, one energy storage element 50 located at the end in the arrangement direction is shown in a state of being removed from the holder 60 to the upper side. The energy storage element 50 is, for example, a capacitor such as an electric double layer capacitor. The energy storage element 50 may be a battery such as a lithium ion battery. The energy storage element 50 has, for example, a cylindrical shape elongated in the width direction with the axis oriented in the width direction. The shape of the energy storage element 50 is not particularly limited, and may be, for example, a rectangular parallelepiped shape. The energy storage element 50 includes a main body 51 and a terminal 52 protruding from the main body 51 to the other side in the width direction. The terminal 52 electrically connects the main body 51 to the circuit board 70.

[0029] FIG. 7 is a perspective view showing a part of the holder 60. As shown in FIG. FIG. 8 is a plan view showing a portion of the holder 60. As shown in FIG. FIG. 9 is an enlarged cross-sectional view showing a part of the cross-sectional view of FIG.

[0030] 7 and 8. The holder 60 is, for example, a resin member, and is integrally molded by injection molding or the like. The holder 60 may be composed of a plurality of members. The holder 60 includes a plurality of recesses 61, a plurality of frame portions 62, an outer frame portion 63, a plurality of holding portions 64, and a plurality of pillar portions 65.

[0031] In this embodiment, eight recesses 61 are formed in the holder 60, equal to the number of the energy storage elements 50. Each of the multiple recesses 61 accommodates one of the multiple energy storage elements 50. The shape of the recess 61 corresponds to the outer circumferential shape of the energy storage element 50, and in this embodiment, is a semi-cylindrical shape that is concave downward. The recess 61 is open upward. The energy storage element 50 is accommodated in the recess 61 with a portion of it (specifically, the upper half of the cylinder) exposed upward.

[0032] The plurality of frame portions 62 are regions extending in the width direction, and each of the frame portions 62 defines two recesses 61 adjacent to each other in the arrangement direction. In this embodiment, seven frame portions 62 are formed in the holder 60, which is one less than the number of recesses 61. Hereinafter, any recess 61 among the plurality of recesses 61 will be appropriately referred to as a "first recess 611", and a recess 61 adjacent to the first recess 611 on one side in the arrangement direction will be appropriately referred to as a "second recess 612". In FIG. 7, the second recess 61 from the end on one side in the arrangement direction will be described as the first recess 611, and the recess 61 at the end on one side in the arrangement direction will be described as the second recess 612, but this is merely an example, and for example, the third recess 61 from the end may be interpreted as the first recess 611.

[0033] Moreover, among the multiple frame portions 62, the frame portion 62 that partitions the first recess 611 and the second recess 612 will be appropriately referred to as a "frame portion 62a." As shown in Fig. 9, the energy storage element 50 accommodated in the first recess 611 will be appropriately referred to as a "first energy storage element 50a," and the energy storage element 50 accommodated in the second recess 612 will be appropriately referred to as a "second energy storage element 50b."

[0034] The outer frame portion 63 is an outer frame formed on the four sides of the holder 60. The outer frame portion 63 includes two first side portions 631 extending in the arrangement direction, two second side portions 632 extending in the width direction, and four corner portions 633 where the first side portions 631 and the second side portions 632 are butted together. The first side portions 631 and the second side portions 632 are each a side of the holder 60, and the corner portions 633 are corners of the holder 60.

[0035] In each drawing, the length of the first side portion 631 in the arrangement direction is longer than the length of the second side portion 632 in the width direction. That is, the first side portion 631 is the long side of the holder 60, and the second side portion 632 is the short side of the holder 60. Note that the holder 60 may have a square shape in which the first side portion 631 and the second side portion 632 are equal in length.

[0036] The multiple holding portions 64 are claw-shaped regions protruding upward from the frame portion 62 or the second side portion 632. The multiple holding portions 64 each come into contact with the energy storage element 50 accommodated in the recess 61, thereby holding the energy storage element 50 in the recess 61. In this embodiment, three holding portions 64 are provided on one frame portion 62, and one or two holding portions 64 are provided on one second side portion 632, but the number of holding portions 64 is not particularly limited.

[0037] Of the multiple holding portions 64, the holding portion 64 that abuts against the energy storage element 50 housed in the recess 61 from one side in the arrangement direction (the right side in FIG. 8) is referred to as a "first holding portion 641." Also, of the multiple holding portions 64, the holding portion 64 that abuts against the energy storage element 50 housed in the recess 61 from the other side in the arrangement direction (the left side in FIG. 8) is referred to as a "second holding portion 642." The energy storage element 50 according to this embodiment is held in the recess 61 at three points by one first holding portion 641 and two second holding portions 642.

[0038] 9. Each of the multiple holding portions 64 includes a guide portion 643 and a contact portion 644. The guide portion 643 is provided at the upper end portion of the holding portion 64, and is a region that guides the outer circumferential surface of the energy storage element 50 when the energy storage element 50 is inserted into the recess 61. The contact portion 644 is a portion of the holding portion 64 that abuts against the energy storage element 50 accommodated in the recess 61. The contact portion 644 is provided below the guide portion 643, for example.

[0039] The guide portion 643 includes an inclined surface. The inclined surface included in the guide portion 643 of the first holding portion 641 is inclined toward one side in the arrangement direction as it goes toward the upper side. The inclined surface included in the guide portion 643 of the second holding portion 642 is inclined toward the other side in the arrangement direction as it goes toward the upper side. In other words, the inclined surface is inclined away from the center in the arrangement direction of the recessed portion 61 in which the energy storage element 50 guided by the guide portion 643 is accommodated.

[0040] When the energy storage element 50 is inserted into the recess 61, the energy storage element 50 is brought relatively closer to the recess 61 in the up-down direction and first comes into contact with the guide portion 643. Then, the outer peripheral surface of the energy storage element 50 slides downward on the inclined surface of the guide portion 643, pushing and widening the guide portion 643 in the arrangement direction. At this time, the holding portion 64 elastically deforms in the arrangement direction. When the apex P2 of the energy storage element 50, which is the widest in the arrangement direction, passes over the guide portion 643 and the abutment portion 644 on the opposite side in the up-down direction, the elastic deformation of the holding portion 64 in the arrangement direction is reduced, and the abutment portion 644 presses the energy storage element 50 into the recess 61. As a result, the energy storage element 50 is accommodated in the recess 61 while being held by the holding portion 64.

[0041] Here, in Patent Document 1, two holding portions face each other with a recess interposed therebetween (paragraph 0038, Figs. 7 and 9 of Patent Document 1). In contrast to this, in this embodiment, the first holding portion 641 and the second holding portion 642 provided on the same frame portion 62 (for example, frame portion 62a) do not overlap when viewed from the arrangement direction, as shown in Fig. 8. That is, when viewed in the arrangement direction, in frame portion 62a, the second holding portion 642 is not formed in the portion where the first holding portion 641 is formed, and the first holding portion 641 is not formed in the portion where the second holding portion 642 is formed.

[0042] With this configuration, the width of the frame 62 in the arrangement direction can be narrowed, thereby making it possible to reduce the size of the holder 60. As a result, the size of the electricity storage unit 10 can be reduced.

[0043] 9, the first holding portion 641 and the second holding portion 642 provided on the same frame portion 62a at least partially overlap each other (portions shown in area A1) when viewed in the width direction. With this configuration, the width of the frame portion 62 in the arrangement direction can be made narrower, and the holder 60 can be made even more compact.

[0044] Please refer to Fig. 8. The frame portion 62 adjacent to the other side of the frame portion 62a in the arrangement direction is referred to as "frame portion 62b". The first holding portion 641 provided on the frame portion 62a overlaps with the first holding portion 641 provided on the frame portion 62b when viewed from the arrangement direction. Furthermore, the second holding portion 642 provided on the frame portion 62a overlaps with the second holding portion 642 provided on the frame portion 62b when viewed from the arrangement direction. In other words, the first holding portion 641 and the second holding portion 642 are arranged alternately (in a staggered pattern).

[0045] By configuring in this manner, the first retaining portion 641 and the second retaining portion 642 can be arranged repeatedly more compactly, so that the width of each of the multiple frame portions 62 in the arrangement direction can be narrowed, thereby making the holder 60 even smaller.

[0046] As shown in Fig. 8, a plurality of second holding portions 642 (two in the example of Fig. 8) are provided on frame portion 62a with gaps between them in the width direction. First holding portion 641 provided on frame portion 62a is located between two second holding portions 642 in the width direction. That is, one of the two second holding portions 642 is located on one side of first holding portion 641 in the width direction, and the other of the two second holding portions 642 is located on the other side of first holding portion 641 in the width direction.

[0047] In this manner, the multiple second holding portions 642 are positioned apart in the width direction with the first holding portion 641 sandwiched therebetween, and therefore the energy storage element 50 can be held at two or more points apart in the width direction. This makes it possible to hold the energy storage element 50 more stably.

[0048] Further, two second holding portions 642 are provided on frame portion 62b with a gap therebetween in the width direction. First holding portion 641 provided on frame portion 62a is located midway between the two second holding portions 642 in the width direction. That is, first power storage element 50a is held at two locations from the other side in the arrangement direction, and at one location midway between the two locations from one side in the arrangement direction. This makes it possible to hold first power storage element 50a more stably while reducing the number of holding portions 64 that hold first power storage element 50a.

[0049] 7 and 9. The multiple pillars 65 are members for preventing the energy storage element 50 from shorting out with the shield unit 30. When the case 31 included in the shield unit 30 is deflected downward due to vehicle vibration or the like, the pillars 65 come into contact with the case 31, thereby preventing the case 31 from deflecting. This prevents a short circuit between the case 31 and the energy storage element 50, which may occur when the deflected case 31 approaches the energy storage element 50 in the vertical direction.

[0050] The multiple pillar portions 65 protrude upward from at least one energy storage element 50 (e.g., first energy storage element 50a) among the multiple energy storage elements 50 housed in the multiple recesses 61, respectively. In this embodiment, the multiple energy storage elements 50 each have the same shape, and the multiple recesses 61 also each have the same shape, so that the multiple pillar portions 65 protrude upward from any of the multiple energy storage elements 50. As shown in Fig. 9, the pillar portions 65 protrude upward from an upper vertex P1 of the energy storage element 50 by a height H1, for example.

[0051] 5, the multiple pillar portions 65 include a first pillar portion 651 and a second pillar portion 652. The first pillar portion 651 is a pillar portion 65 that protrudes upward from a corner (i.e., corner portion 633) of the holder 60 among the multiple pillar portions 65. The second pillar portion 652 is a pillar portion 65 that protrudes upward from a side (i.e., first side portion 631 or second side portion 632) of the holder 60 among the multiple pillar portions 65.

[0052] By providing the pillars 65 at the corners or sides of the holder 60, the bent case 31 can be supported, and the pillars 65 can increase the rigidity of the outer frame 63 of the holder 60, thereby suppressing the bending of the holder 60. This also makes it possible to suppress a short circuit caused by the holder 60 bending and the energy storage element 50 held by the holder 60 coming closer to the case 31.

[0053] Please refer to Figures 5 and 6. Circuit board 70 is a board including a control circuit that controls charging and discharging of the multiple energy storage elements 50. Circuit board 70 is fixed to the underside of holder 60 by fastening members such as bolts and nuts with circuit surface 71 on which wiring 72 is formed facing upward. Wiring 72 includes an area for electrical connection with energy storage elements 50. The multiple energy storage elements 50 are connected in series to wiring 72, for example. Wiring 72 has power supply line 73a connected to the power supply side (+ side) of the vehicle and ground line 73b connected to the ground potential of the vehicle body, etc.

[0054] The circuit board 70 has a connector portion 74 that electrically connects the wiring 72 and the external wiring, and a connector surface 75 (back surface) that is the surface behind the circuit surface 71 and on which the connector portion 74 is provided. The power extracted from the multiple energy storage elements 50 to the wiring 72 is supplied to the external wiring via the connector portion 74.

[0055] <3. Configuration of the shield unit 30> Please refer to Figs. 2 to 4. The shield unit 30 functions as a shield for protecting the multiple energy storage elements 50 from external noise. The shield unit 30 includes a metal case 31 and a metal mating case 32. The case 31 is a substantially rectangular parallelepiped housing that is open on the bottom side. The thickness of the case 31 is, for example, within a range of 0.2 mm to 0.8 mm, and specifically, for example, 0.5 mm. The case 31 is formed of, for example, a steel material such as SPCC (cold rolled steel plate) or SUS304. The mating case 32 is a substantially rectangular parallelepiped housing that is open on the top side, and is formed of, for example, the same thickness and material as the case 31.

[0056] The case 31 includes an opposing wall 311, a side wall 312, and an open end 313. The opposing wall 311 is a wall that faces the multiple energy storage elements 50 and the holder 60 in the up-down direction, and in this embodiment is a plate-shaped region that extends along the arrangement direction and the width direction. The side walls 312 are four walls that extend downward from the periphery of the opposing wall 311, and are a region that supports the opposing wall 311 in a state where it faces the multiple energy storage elements 50 and the holder 60.

[0057] The open end 313 is an end provided on the lower side of the side wall 312. The case 31 is open downward at the open end 313. In this embodiment, the open end 313 is provided on the lower side of the case 31 in a "brim" shape.

[0058] The open end 313 is fixed to the circuit surface 71 of the circuit board 70 by fastening members (not shown) such as bolts and nuts in a state where it is electrically connected to the ground line 73b of the circuit board 70. This brings the entire case 31 to the ground potential. By housing the multiple energy storage elements 50 together with the holder 60 in the case 31 at the ground potential, the energy storage elements 50 can be protected from electrical noise outside the case 31.

[0059] Similar to the case 31, the mating case 32 includes an opposing wall 321, side walls 322, and an open end 323. The opposing wall 321 is a wall that faces the connector surface 75 of the circuit board 70 in the up-down direction, and in this embodiment is a plate-like region that extends along the arrangement direction and width direction. The side walls 322 are four walls that extend upward from the periphery of the opposing wall 321, and are a region that supports the opposing wall 321 in a state where it faces the connector surface 75. The side walls 322 include a notch C1 for exposing the connector portion 74 to the outside.

[0060] The open end 323 is an end provided on the upper side of the side wall 322. The mating case 32 is open upward at the open end 323. The open end 323 in this embodiment is provided on the upper side of the mating case 32 in a "brim" shape.

[0061] The open end 323 is fixed to the connector surface 75 of the circuit board 70 by fastening members such as bolts and nuts (not shown) in a state where it is electrically connected to the ground line 73 of the circuit board 70. As a result, the entire mating case 32 is at ground potential, and the shield unit 30 is at ground potential.

[0062] By housing the board unit 20 in the shield unit 30 at ground potential, the board unit 20 can be protected more reliably from electrical noise external to the shield unit 30.

[0063] The relationship between the opposing wall 311 of the case 31 and the column portion 65 will be described with reference to Fig. 9. Because the opposing wall 311 is made of metal, when the opposing wall 311 and the energy storage element 50 come close to each other (or come into contact), charges stored in the energy storage element 50 may flow to the opposing wall 311, causing a short circuit. For this reason, from the viewpoint of preventing short circuits, it is preferable that the vertical gap between the opposing wall 311 and the energy storage element 50 is large. On the other hand, from the viewpoint of miniaturizing the energy storage unit 10, it is preferable that the gap is small.

[0064] For this reason, the gap between opposing wall 311 and energy storage element 50 (the distance from upper vertex P1 of energy storage element 50 to opposing wall 311) is made as small as possible without causing a short circuit between energy storage element 50 and opposing wall 311.

[0065] Here, from the viewpoint of reducing the size and weight of the energy storage unit 10, it is preferable that the thickness of the case 31 is thin. However, if the case 31 is formed thin, the opposing wall 311 may be significantly deflected downward due to, for example, vibration of a vehicle mounting the energy storage unit 10. If the gap between the energy storage element 50 and the opposing wall 311 is formed as small as possible without causing a short circuit between the energy storage element 50 and the opposing wall 311, when the opposing wall 311 is deflected downward in this manner, there is a risk that the energy storage element 50 will be short-circuited with the opposing wall 311.

[0066] Therefore, in this embodiment, the opposing wall 311 bending downward is supported by the pillar portion 65, thereby preventing the opposing wall 311 from approaching the energy storage element 50. In other words, when the opposing wall 311 bends downward, the pillar portion 65 comes into contact with the opposing wall 311 before the energy storage element 50 does, thereby preventing the opposing wall 311 from bending. This maintains a gap between the opposing wall 311 and the energy storage element 50, thereby preventing the energy storage element 50 from shorting out with the opposing wall 311.

[0067] In this manner, in this embodiment, by including the pillar portion 65, it is not necessary to design the gap between the case 31 and the energy storage element 50 to be excessively large by taking into account the amount of bending of the case 31 in order to suppress a short circuit. In other words, the gap between the case 31 and the energy storage element 50 can be made smaller. This allows the energy storage unit 10 to be made smaller.

[0068] Here, when the opposing wall 311 is not bent in the up-down direction, the pillar portion 65 faces the opposing wall 311 with a gap D1 in the up-down direction. In other words, when the opposing wall 311 is not bent in the up-down direction, the pillar portion 65 is not in contact with the opposing wall 311.

[0069] Because holder 60 is formed, for example, by injection molding, there may be a tolerance of about 0.1 mm in the vertical height of column 65. If column 65 is provided so as to be in constant contact with non-flexing opposing wall 311, the tolerance of column 65 may cause case 31 to float in the vertical direction from circuit board 70, which may result in the electrical connection between case 31 and ground line 73b being cut off.

[0070] In this embodiment, the pillar portion 65 faces the non-flexible opposing wall 311 with a gap D1 in the vertical direction, so that the effects of tolerances are absorbed by the gap D1, and the case 31 can be prevented from constantly floating in the vertical direction from the circuit board 70.

[0071] Furthermore, vibration may cause the opposing wall 311 to bend slightly while maintaining a gap that does not cause a short circuit with the energy storage element 50. In such a case, if the pillar portion 65 is configured to come into contact with the opposing wall 311 each time the opposing wall 311 bends slightly, the pillar portion 65 may push the case 31 up and down, which may place a strain on the fastening portion between the case 31 and the circuit board 70. In this case, the bolts and nuts fastening the case 31 and the circuit board 70 may easily come loose, or the electrical connection between the case 31 and the ground line 73b may frequently come loose.

[0072] Due to the gap D1, the pillar portion 65 of this embodiment does not come into contact with the opposing wall 311 when the opposing wall 311 bends slightly, but can come into contact with the opposing wall 311 only when the opposing wall 311 bends significantly to the extent that there is a risk of short-circuiting with the energy storage element 50. This can reduce the load on the fastening portion between the case 31 and the circuit board 70. Also, the electrical connection between the case 31 and the ground line 73b can be more continuously maintained.

[0073] <4. Configuration of cover unit 40> 2 to 4. The cover unit 40 includes a resin cover 41 and a resin mating cover 42. The cover 41 is a substantially rectangular parallelepiped housing that is open downward. The cover 41 covers the board unit 20 and the shield unit 30 from above. A plurality of protrusions 41a are formed on the inside (case 31 side) of the cover 41. The protrusions 41a are in contact with the opposing wall 311 of the case 31 in the up-down direction, and suppress the opposing wall 311 from bending upward. In other words, the upward bending of the opposing wall 311 is suppressed by the protrusions 41a, and the downward bending of the opposing wall 311 is suppressed by the pillars 65.

[0074] The mating cover 42 is a substantially rectangular parallelepiped housing that is open on the upper side. The mating cover 42 covers the board unit 20 and the shield unit 30 from below, with the connector portion 74 exposed to the outside.

[0075] In the energy storage unit 10 of this embodiment, the metallic shield unit 30 is located inside the resin cover unit 40. Therefore, the cover unit 40 can protect the shield unit 30 from configurations outside the energy storage unit 10 (for example, the frame of a vehicle body on which the energy storage unit 10 is installed, etc.). Because of the protection provided by the cover unit 40, there is little problem even if the strength of the shield unit 30 is weakened. Therefore, by providing the cover unit 40, the shield unit 30 can be formed thinner, and the weight of the energy storage unit 10 can be reduced.

[0076] <5. Modifications> Modifications of the embodiment will be described below. In the modifications, parts that are unchanged from the embodiment will be given the same reference numerals and descriptions thereof will be omitted.

[0077] <5.1 Modification 1 of the column portion 65> FIG. 10 is a cross-sectional view showing a part of the electricity storage unit 10 according to a modified example. The multiple pillar portions 65 may include a third pillar portion 653 protruding in the vertical direction from the holding portion 64. For example, the third pillar portion 653 is formed by further extending the upper tip of the holding portion 64. The third pillar portion 653 is higher than the apex P1 of the energy storage element 50 by a height H2, and faces the opposing wall 311 with a gap D2 in the vertical direction therebetween.

[0078] The opposing wall 311 tends to bend more in a region farther from the side wall 312 (i.e., the central region in the arrangement direction and width direction of the opposing wall 311). Since the third column portion 653 is provided in the holding portion 64, it can face the central region of the opposing wall 311 in the up-down direction and can support the portion of the opposing wall 311 that is more greatly bent. This makes it possible to more reliably suppress a short circuit between the energy storage element 50 and the opposing wall 311.

[0079] In addition, since the third columnar portion 653 is additionally formed on the holding portion 64, which is a configuration provided for holding the energy storage elements 50, the amount of resin required for its formation can be reduced compared with the first columnar portion 651 and the second columnar portion 652 formed on the outer frame portion 63. This makes it possible to reduce the weight of the energy storage unit 10 and cut the material cost of the resin.

[0080] The third pillars 653 may be formed on all of the retaining portions 64, or may be formed on some of the retaining portions 64. When the third pillars 653 are formed on some of the retaining portions 64, for example, they may be formed on the retaining portions 64 located at the center in the arrangement direction (in the example of FIG. 6, the three retaining portions 64 provided on the fourth frame portion 62 from the left and right) or on the retaining portions 64 located at the center in the width direction (in the example of FIG. 6, the eight first retaining portions 641) to support the portion of the opposing wall 311 that is subject to large deflection.

[0081] <5.2 Modification 2 of the column portion 65> In the above embodiment and modified examples, the holder 60 is provided with a plurality of pillars 65. However, the holder 60 may be provided with only one pillar 65. For example, only the centrally located holding portion 64 (in the example of FIG. 6, the first holding portion 641 provided on the fourth frame portion 62 from the left and right) may be provided with only one third pillar 653. With this configuration, the number of pillars 65 can be reduced to reduce the weight of the electricity storage unit 10, and the portion of the opposing wall 311 that is subject to large deflection can be supported.

[0082] <5.3 Modification 1 of the holding portion 64> FIG. 11 is a plan view that diagrammatically illustrates a portion of the energy storage unit 10 according to a modified example. In a holder 60a according to this modification, the arrangement of the holding portion 64 is different from that of the holder 60 of the embodiment, but the other configurations are the same as those of the embodiment.

[0083] In the above embodiment, the holding portions 64 are arranged in a staggered pattern, and the first holding portion 641 and the second holding portion 642 that hold one energy storage element 50 do not overlap when viewed in the arrangement direction. However, the arrangement of the holding portions 64 in the present disclosure is not limited to this, and such first holding portion 641 and second holding portion 642 may overlap when viewed in the arrangement direction.

[0084] 11, first holding portion 641 and second holding portion 642 that hold first power storage element 50a are referred to as "first holding portion 641a" and "second holding portion 642a", respectively. Also, first holding portion 641 and second holding portion 642 that hold second power storage element 50b are referred to as "first holding portion 641b" and "second holding portion 642b", respectively.

[0085] The first holding portion 641a and the second holding portion 642b are provided one each on the frame portion 62a that defines the first recess 611 and the second recess 612. As in the above embodiment, the first holding portion 641a does not overlap the second holding portion 642b when viewed from the arrangement direction.

[0086] The second retaining portion 642a is provided on the frame portion 62b adjacent to the frame portion 62a on the opposite side in the arrangement direction. When viewed from the arrangement direction, the second retaining portion 642a overlaps with the first retaining portion 641a, but does not overlap with the second retaining portion 642b. Similarly, the first retaining portion 641b is provided on the frame portion 62c (the second side portion 632 in the example of FIG. 2) adjacent to the frame portion 62a in the arrangement direction. When viewed from the arrangement direction, the first retaining portion 641b overlaps with the second retaining portion 642b, but does not overlap with the first retaining portion 641a.

[0087] In the above embodiment, the first holding portion 641 and the second holding portion 642 are not directly opposite each other in the arrangement direction, so while multiple storage elements 50 can be held at the same location (holding conditions can be made uniform), it was necessary to hold the storage elements 50 at at least three locations.

[0088] In contrast, the second holding portion 642a according to the modification faces the first holding portion 641a in the arrangement direction, and therefore the first storage element 50a can be stably held by the two positions of the first holding portion 641a and the second holding portion 642a. The first holding portion 641b according to the modification faces the second holding portion 642b in the arrangement direction, and therefore the second storage element 50b can be stably held by the two positions of the first holding portion 641b and the second holding portion 642b. This allows the number of holding portions 64 to be reduced, and the weight of the storage unit 10 to be reduced, compared to the above embodiment.

[0089] <5.4 Modification 2 of the holding portion 64> In the above embodiment, one energy storage element 50 is held by three holding parts 64. However, the number of holding parts 64 used to hold one energy storage element 50 is not particularly limited as long as it is two or more. Also, in the above embodiment, all energy storage elements 50 are held by three holding parts 64, but the number of holding parts 64 that hold the energy storage elements 50 in one holder 60 may be different.

[0090] For example, two energy storage elements 50 housed in recesses 61 at both ends in the arrangement direction adjacent to outer frame portion 63 may be held by four holding portions 64, and the remaining energy storage elements 50 may be held by three holding portions 64. Since outer frame portion 63 has room to provide more holding portions 64 than frame portion 62, more holding portions 64 may be provided.

[0091] Furthermore, the energy storage elements 50 accommodated in the recesses 61 near the center in the arrangement direction may be held by more holding parts 64 than the other energy storage elements 50. The deflection of the holder 60 tends to be greatest near the center in the arrangement direction. Therefore, by holding the energy storage elements 50 accommodated in the portion with the greatest deflection by more holding parts 64, the energy storage elements 50 can be held more stably.

[0092] <5.5 Modifications of the Energy Storage Element> In the above embodiment, a plurality of energy storage elements 50 are housed in the holder 60. However, the number of energy storage elements 50 housed in the holder 60 may be only one.

[0093] <6. Additional Notes> In addition, at least a part of the above-mentioned embodiment and various modified examples may be arbitrarily combined with each other. In addition, the embodiment disclosed herein should be considered to be illustrative and not restrictive in all respects. The scope of the present disclosure is defined by the claims, and it is intended to include all modifications within the meaning and scope of the claims. [Explanation of symbols]

[0094] 10 Energy storage unit 20 Circuit Board Unit 30 Shield Unit 31 cases 311 Facing Wall 312 Side wall 313 Open end 32 Opponent Case 321 Facing Wall 322 Side wall 323 Open end 40 Cover unit 41 Cover 41a Convex part 42 Opponent Cover 50 Energy storage element 50a First storage element 50b Second storage element 51 Main unit 52 Terminals 60 Holder 60a Holder 61 Recess 611 First recess 612 Second recess 62 Frame 62a Frame 62b Frame 62c frame 63 Outer frame 631 First side 632 Second side 633 Corner 64 Holding part 641 1st holding part 641a 1st holding part 641b 1st holding part 642 Second holding part 642a 2nd holding part 642b 2nd holding part 643 Information Department 644 Contact part 65 Column section 651 1st pillar section 652 2nd pillar section 653 3rd pillar section 70 Circuit Board 71 Circuit surface 72 Wiring 73a Power Line 73b Grand Line 74 Connector part 75 Connector surface A1 area P1 Vertex P2 Vertex H1 Height H2 Height D1 Gap D2 Gap C1 Cutout

Claims

1. a resin holder that houses the storage element with a portion of the storage element exposed on an upper side; a circuit board including wiring electrically connected to the power storage element and fixed to a lower side of the holder; a metal case that houses the energy storage element and the holder by fixing the open end that is open downward to the circuit board; Equipped with The holder includes one or more pillar portions protruding upward beyond the storage element. Energy storage unit.

2. the case includes an opposing wall that faces the storage element and the holder in a vertical direction, When the opposing wall bends downward, the one or more pillar portions come into contact with the opposing wall before the storage element comes into contact with the opposing wall. The power storage unit according to claim 1 .

3. The wiring includes a ground line, the open end is electrically connected to the ground line, The one or more pillar portions face the opposing wall with a gap therebetween in the vertical direction when the opposing wall is not deflected. The power storage unit according to claim 2 .

4. The one or more pillars may include A first pillar portion protruding upward from a corner of the holder; and a second pillar portion protruding upward from a side of the holder; At least one of the following: The power storage unit according to any one of claims 1 to 3.

5. The storage elements are arranged in a plurality of rows in an arrangement direction intersecting the up-down direction, The holder includes: A plurality of recesses each accommodating a plurality of the energy storage elements; A frame portion that partitions two recesses adjacent to each other in the arrangement direction among the plurality of recesses; a holding portion that protrudes upward from the frame portion and holds the energy storage element by abutting against the energy storage element accommodated in the recess in the arrangement direction; Including, The one or more pillar portions include a third pillar portion protruding upward from the holding portion, The power storage unit according to any one of claims 1 to 4.

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