JP2008166060A - Battery pack - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a battery pack wherein case members are bonded with their opening parts in a face to face state to contain unit cells, and the case members can be prevented from being disconnected from each other. <P>SOLUTION: A support shelf 60 to support a circuit board 19 in the thickness direction of a case 30 in cooperation with the bottom face 42 of the first case member 40 between a pair of the first and second case members 40, 50 in the shape of a rectangular parallelepiped is extended toward the inner part of the case 30 from the fringe of the opening part 51 of the second case member 50, and a rib 70 is extended to connect the inner main face of the side wall crossing the support shelf 60 in the second case member 50 with the inner main face of the side wall in the support shelf 60. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a battery pack, and more particularly to a technique for improving the strength of such a battery.

  Since a battery used for the power source of a mobile electric device such as a mobile phone may be carried alone, a unit cell (hereinafter referred to as “cell”) is housed in a case from the viewpoint of impact protection. A battery pack is used. In recent years, with the increase in functionality and usage time of mobile electrical devices, it has been required to improve the capacity of the battery pack as a power source. To meet this demand, a plurality of cells, for example, 2 cells are accommodated. Thus, a battery pack (hereinafter referred to as “L battery pack”) has appeared.

  Lithium ion batteries are mainly used for the cells because of their high energy density and large output current. In the L pack battery, for example, two plate-like cells are electrically and structurally connected in parallel. Further, the life of the lithium ion battery is shortened due to overcharge, overdischarge, and the like. In order to prevent such inconvenience, a charge / discharge control circuit is housed in the battery pack when a lithium ion battery is employed in the cell.

The board of the charge / discharge control circuit of the L pack battery is the same size as the board of the charge / discharge control circuit of the pack battery of 1 cell from the viewpoint of cost reduction, and is opposed to one of the cell ends. In general, it is arranged and supported in a case (see Patent Documents 1 and 2).
In Patent Document 1, the size of the cell in the longitudinal direction of the case is changed between a cell whose end is opposed to the substrate and a cell whose end is not opposed to the substrate. A configuration is disclosed in which a shelf is provided inside the case by being recessed from the outside, and the substrate is directly or indirectly supported by the shelf (see FIGS. 4 and 5 of Patent Document 1).
JP 2004-63383 A JP 2006-164579 A

  However, including the configuration disclosed in Patent Document 1, generally in battery packs for mobile devices, there is almost no gap between the case and the cell or the charge / discharge control circuit in order to satisfy the requirements for reduction in size and weight. Moreover, it tends to be thinner. For this reason, when an impact is applied to the case, the case may be greatly bent, whereby the case contents, mainly the charge / discharge control circuit, may be destroyed, and the case may be opened.

When a step is formed inside the case edge as in Patent Document 1, a dent is generated in the case appearance, and considering that the standard battery pack containing only one cell is shared in the target device, the case edge It is preferable that there is no dent on the outside.
The present invention has been made in view of the above problems, and when the impact is applied to the case without impairing the compatibility, the case storage is destroyed by suppressing the bending of the case. It aims at providing the battery pack which can suppress and can prevent that a case opens.

  In order to solve the above-described problems, a battery pack according to the present invention includes a unit case in which a plurality of unit cells are stored in a stacked state in the unit cell storage space, and any one unit cell excluding the lowermost unit cell is included. A circuit board for controlling charging / discharging of the battery is stored along the inner surface of the case so as to face the one end surface of the battery, and a support shelf that supports the lower edge of the circuit board from the inner surface of the case behind the circuit board. In addition to projecting toward the battery side, a reinforcing rib was provided from the support shelf to the case bottom surface in a space directly surrounded by the other cell end face and the case inner side surface directly below the support shelf.

  In the battery pack according to the present invention, the unit cell is housed in a case, and at least a reinforcing rib is disposed from one main surface to the other main surface in a side wall surrounding the inner main surface of the case, Reinforcing ribs include a first rib element extending from the one main surface toward the other main surface, a second rib element extending from the other main surface toward the one main surface, the first rib element, and the first rib The two rib elements were formed in combination with the lateral ribs reached by the two rib elements, and the first rib elements and the second rib elements were made to reach the lateral ribs while being shifted from each other.

  In the battery pack according to the present invention, the rib is disposed from the support shelf to the case bottom surface in a space surrounded by the other cell end face and the case inner side surface directly below the support shelf. Compared with the case where the rib is not provided, the bending strength of the case inner surface and the support shelf can be improved. Therefore, in the battery pack according to the present invention, when an impact is applied to the case, it is possible to prevent the case inner side surface from being greatly bent outward or inward of the case, compared to a case where the rib is not provided. It is possible to suppress destruction of the case contents, mainly the substrate of the charge / discharge control circuit.

  The case housing is formed by joining a pair of rectangular parallelepiped case members at each opening, and assuming a virtual plane passing through the periphery of the opening, the reinforcing ribs are arranged so as to intersect the virtual plane. When the shock is applied to the case housing, it is possible to prevent the case inner side surface from being greatly bent outward or inward of the case, compared to the case where the reinforcing rib is not provided. And the case housing can be prevented from opening.

  In the battery pack according to the present invention, the circuit board can be supported by a support shelf protruding from the inner side surface of the case to the unit cell side. Therefore, a step is formed at the end of the case as in the configuration disclosed in Patent Document 1. Therefore, there is no need to provide a dent in the appearance of the case. Therefore, compatibility with a standard battery pack containing one cell can be ensured when mounted on an electric device.

  When a plurality of the reinforcing ribs are formed and the reinforcing ribs of each of the strips are made thicker as they approach the bottom of the case, the reinforcing ribs have the same width as the smaller rib width and a uniform width. Can be prevented from being bent in the rib width direction, the case storage can be improved, and the effect of suppressing mainly the substrate of the charge / discharge control circuit can be improved, and the case can be prevented from opening. It can be improved and is preferable.

  When the reinforcing rib is formed by a combination of a vertical rib extending from the support shelf toward the bottom surface of the case and a horizontal rib intersecting with the vertical rib, when an impact is applied to the case, the vertical rib is in the rib width direction. Since the lateral rib suppresses bending, the rib bending suppression action can be improved, and the effect of suppressing destruction of the case contents, mainly the substrate of the charge / discharge control circuit, can be improved. The effect which suppresses that the said case opens can be improved.

  Therefore, even if the width of the vertical rib is reduced and made uniform, the case stored item destruction suppressing effect and the case opening suppressing effect can be obtained. Note that reducing the width of the vertical rib to make it uniform suppresses the occurrence of sink marks on the outer surface of the bottom of the case corresponding to the bottom end of the rib when the molten material is poured into the mold. This is preferable because the yield of the battery pack can be improved.

  The reinforcing rib reaches the first rib element from the support shelf toward the case bottom, the second rib element from the case bottom toward the support shelf, and both the first rib element and the second rib element. When the first rib element and the second rib element are made to be combined with the lateral rib and are shifted from each other with respect to the lateral rib, the first rib element and the second rib element are displaced from each other. Since it has reached the horizontal rib in a state where it is in contact, when an impact is applied to the case, the horizontal rib bends and absorbs the impact. Therefore, in such a case, when an impact is applied to the case, the impact can be made difficult to be transmitted to the circuit board due to the deflection of the lateral rib, and the breakage of the circuit board can be suppressed.

Further, in such a case, when the impact is applied, the impact of the lateral rib can be made difficult to be transmitted from the second rib element to the bottom surface of the case, and the arrival point of the second rib element It is possible to prevent whitening from occurring due to plastic deformation at the bottom corresponding to. Therefore, even if an impact is applied to the case for some reason, it is difficult to become a defective product.
Further, since the first rib element and the second rib element have reached the lateral rib in a state where they have passed, the reinforcing rib is moved from the support shelf to the case bottom and the vertical rib and the vertical rib. Compared to the case of forming with a combination of ribs and transverse ribs, when the molten material is poured into the mold and molded, the amount of material concentrated at the intersection can be suppressed, so the above-mentioned case inner side surface It is possible to suppress the occurrence of sink marks on the outer side surfaces corresponding to the intersections of the reinforcing ribs.

When two prismatic cells are accommodated in the unit cell storage space in the case housing, the same effects as described above can be obtained.
In the battery pack according to the present invention, a unit cell is accommodated in a case, and at least a reinforcing rib is disposed from one main surface to the other main surface on a side wall surrounding the inner main surface of the case, and the reinforcing rib is provided. The first rib element from the one main surface to the other main surface, the second rib element from the other main surface to the one main surface, the first rib element and the second rib Since the first rib element and the second rib element are formed in a state of being shifted from each other with respect to the lateral rib, the same effect as described above can be obtained. Play. That is, as compared with the case where each of the first rib element, the second rib element, and the lateral rib is not provided, at least the bending strength of the side wall can be improved, and the first rib element and the above-mentioned Since the second rib element has reached the horizontal rib in a state of being shifted from each other, when the shock is applied to the case, the horizontal rib is bent to absorb the shock.

  In this way, the case ribs can be prevented from being broken and the case can be prevented from opening by bending the lateral rib.

Hereinafter, the case where the battery pack according to the present invention is applied to a battery pack including two cells will be described as an example. However, the embodiment described below exemplifies a battery pack that embodies the technical idea of the present invention, and the present invention is not limited to the following.
Moreover, this Embodiment does not limit the member described in the claim to the member described in this Embodiment. The size, positional relationship, and the like of the members shown in each drawing may be exaggerated to facilitate understanding. Further, in the following description, the same name and reference sign indicate the same and the same members, and the detailed description will be omitted as appropriate.

[Embodiment 1]
<Configuration of battery pack>
FIG. 1A is an exploded perspective view of the battery pack according to the present embodiment, and FIG. 1B is a schematic cross-sectional view of the battery pack according to the present embodiment. As shown in FIG. 1A, in the battery pack 100, the battery unit 20 is included in a rectangular parallelepiped case 30, and the case 30 includes a pair of rectangular parallelepiped first case members 40 and a rectangular parallelepiped second case. The case member 50 is bonded to each other with the openings 41 and 51 attached to each other, and has a unit cell storage space. In the present embodiment, the openings 41 and 51 of both the first case member 40 and the second case member 50 are brought into contact with each other, and sealing is performed between the openings 41 and 51. In a state where the two case members 50 are temporarily fixed, a heat shrink tape (not shown) is wound around the Y axis around the Y axis and is thermally contracted to join each other. At this time, both ends of the case 30 are not covered with a heat shrink tape (not shown) and are exposed.

The method of joining the first case member 40 and the second case member 50 is an example, and the present invention is not limited to this. For example, the first case member 40 and the second case member 50 may be ultrasonically welded and joined in a state where the openings 41 and 51 are attached to each other.
<Configuration of battery unit>
The battery unit 20 includes a circuit board 19 having a charge / discharge control circuit and unit cells 17 and 18 (hereinafter referred to as “cells”). In the present embodiment, two rectangular cells 17 and 18 are provided, and a lithium ion battery is adopted as the cells 17 and 18, and the life of the lithium ion battery is remarkably reduced due to overcharge, overdischarge, etc. In order to prevent this, the battery unit 20 is provided with a charge / discharge control circuit for controlling charge / discharge of all the cells 17, 18. In the present embodiment, two cells 17 and 18 are provided, but the number of cells 17 and 18 is not limited to this, and may be three or more, and each of cells 17 and 18 may not be square. .

The circuit board 19 having the charge / discharge control circuit is present in the case 30 so as to face the end of one cell 18 from the viewpoint of sharing parts with the battery pack containing one cell and reducing costs. Yes.
The circuit board 19 having the charge / discharge control circuit can be electrically connected to a terminal on the electric device side through an opening (not shown) provided on the side wall of the first case member 40 facing the circuit board 19. A connector (not shown) is provided, and the connector is provided with a plus terminal, a minus terminal, and a connection detection terminal. The positive terminal and the negative terminal are for charging / discharging with an electronic device not shown, and the connection detection terminal detects whether or not the battery pack 100 is normally connected to the electronic device not shown. Used for.

  The circuit board 19 is provided with an unillustrated audit circuit and switching circuit. The audit circuit is composed of a measurement unit and a determination unit that determines abnormality based on a signal from the measurement unit, and the determination unit determines whether the abnormality is based on information sent from the measurement unit. To stop charging and discharging. For example, a microcomputer is used as the determination unit. The measurement unit includes a current measurement circuit, a voltage measurement circuit, a temperature measurement circuit, and the like that measure the current, voltage, heat generation temperature, and the like of the cells 17 and 18 respectively.

In this embodiment, the cells 17 and 18 are stacked in two stages, and are bonded to each other with a double-sided adhesive tape 16. Although not shown, the double-sided adhesive tape 16 is arranged in a frame shape between the main surfaces of the cells 17 and 18, so that the closed gap 13 is formed between the opposing main surfaces of the cells 17 and 18. Provided (see FIG. 1B).
By providing the closed gap 13, even if the cells 17 and 18 expand in a state where the cells 17 and 18 are accommodated in the case 30, the expansion can be absorbed and the thickness direction of the battery pack 100 can be absorbed. Can be suppressed.

  In the present embodiment, the cells 17 and 18 are stacked in a state in which the respective positive electrodes or negative electrodes are arranged on the same side, and the strip-shaped lead plates 14 and 15 are arranged so as to bridge the positive electrodes or the negative electrodes. Are electrically connected in parallel. Note that the cells 17 and 18 can be electrically connected in parallel even if the respective positive electrodes or negative electrodes are stacked without being arranged on the same side.

<Case configuration>
As shown in FIG. 1A, the case 30 is divided in the thickness direction of the battery unit 20 and is divided into a first case member 40 and a second case member 50 that form a pair. Both the first case member 40 and the second case member 50 are preferably formed of an insulating material. In the present embodiment, both the first case member 40 and the second case member 50 are made of polycarbonate. The material of the 1st case member 40 and the 2nd case member 50 is not limited to this, Other plastic materials, for example, PPS (polyphenylene sulfite), may be sufficient.

Each of the first case member 40 and the second case member 50 includes openings 41 and 51 for inserting the cells 17 and 18 of the battery unit 20, and has a bottom for supporting the cells 17 and 18. In addition, each cell 17, 18 or a side wall that surrounds the bottom is provided, a depth sufficient to accommodate one cell, and a cell storage space.
In a state in which the first case member 40 and the second case member 50 are associated with each other opening portions 41 and 51, that is, in a state in which the case 30 is closed, the battery unit 20 is not stably fixed and is not fixed inside the case 30. The gap distance between the opposing main surfaces of the case members 40, 50, that is, the opposing bottom surfaces 42, 52 is substantially the same as the thickness of the battery unit 20 (the length in the Z-axis direction) so as not to be violated.

Further, the gap distance L3 between the side walls arranged in parallel in the short direction (X-axis direction) of each of the first case member 40 and the second case member 50 is not fixed stably and the battery unit 20 is not stably fixed. Therefore, the lengths of the cells 17 and 18 substantially coincide with the length L2 in the short direction (X-axis direction).
In the present embodiment, from the viewpoint of component sharing and cost reduction, a battery pack containing only one cell, that is, a circuit board 19 having the same size as a standard battery pack is used. The circuit board 19 is provided to face the end of the cell 18 and does not face the end of the cell 18.

The side wall of the first case member 40 that faces the circuit board 19 of the battery unit 20 is provided with an opening that exposes the connector provided on the circuit board 19 of the battery unit 20, although not shown in the figure. .
As shown in FIG. 1 (b), in the present embodiment, the longitudinal direction of both the first case member 40 and the second case member 50 is taken into consideration for compatibility with a standard battery pack when mounted on a device. (Length in the Y-axis direction) L4 and L5 are set to be the same. Further, the thickness of the side wall of the case 30 is substantially constant from the viewpoint of weight reduction. Therefore, in the present embodiment, of the cells 17 and 18 of the battery unit 20, the end of the cell 17 directly below the support shelf 60, in other words, the end of the cell 17 of the lowermost layer, A space 55 is provided between the end of the cell 17 and the inner surface of the side wall 54 facing the cell 17.

In the second case member 50, the support shelf 60 that supports the circuit board 19 of the battery unit 20 at the lower edge between the bottom inner surface of the first case member 40 and a direction approaching the cells 17, 18, that is, The second case member 50 protrudes from the one side wall 54 toward the cells 17 and 18.
In the second case member 50, the inner main surface of the one side wall 54 and the bottom main surface of the second case member 50 of the support shelf 60 are connected from the support shelf 60 to the bottom thereof. Further, the reinforcing rib 70 reaching the bottom of the second case member 50 is extended in the case member abutting direction (Z-axis direction).

In other words, when assuming a virtual plane passing through the opening periphery of each of the first case member 40 and the second case member 50, the reinforcing ribs 70 are arranged so as to intersect the virtual plane.
The height (the length in the Y-axis direction) L7 of the reinforcing rib 70 is the longitudinal direction (Y-axis) of the second case member 50 in order to prevent the battery unit 20 from being stably fixed and being exposed inside the case 30. Direction), the gap distance L6 between the top of the reinforcing rib 70 provided on the one side wall 54 and the top of the rib 53 on the other side wall is not opposite to the circuit board 19. The cell 17 is set so as to substantially match the length in the longitudinal direction (Y-axis direction).

  In the present embodiment, the rib 53 is provided on the other side wall, but this is because the cell 17 is longer than the length of the case 30 because of the length of the cell 17 in the longitudinal direction (the length in the Y-axis direction). The length of the cell 17 in the longitudinal direction (the length in the Y-axis direction) is the top of the rib 70 in the second case member 50, and is provided to suppress wobbling in the direction (Y-axis direction). If it is almost the same as the gap distance with the side wall arranged at the position facing the top, it is not necessary, and if there is a similar situation, the first case member 40 is provided at a position corresponding to the rib 53. There is no need to have ribs.

FIG. 2 is a schematic cross-sectional view of the second case member 50 of the battery pack according to the present embodiment, and is a cross-sectional view taken along the A line shown in FIG.
In the present embodiment, in the reinforcing rib 70, the width d1 of the extending end on the opening 51 side of the second case member 50 is different from the width d2 of the extending end on the bottom side.
As shown in FIG. 2, the reinforcing rib increases in width as it approaches the bottom surface 52 of the second case member 50 from the bottom-side main surface of the second case member 50 in the support shelf 60, that is, gradually increases its width. The support shelf 60 and the bottom surface 52 are integrally formed. In the reinforcing rib 70, the width d2 of the extended end on the bottom surface 52 side is larger than the width d1 of the extended end on the support shelf 60 side. In the present embodiment, for example, four reinforcing ribs 70 are parallel to each other. Of course, the number of the reinforcing ribs 70 is not limited to this, and the number can be appropriately determined from the viewpoint of the target bending strength and the like.

  In the present embodiment, from the viewpoint of reduction in size and weight, the width d1 of the extending end of the reinforcing rib 70 on the support shelf 60 side is set to 0.25 [mm], and the reinforcing rib 70 extends on the bottom surface 52 side. The end width d2 is set to 0.35 [mm]. The bottom of the second case member 50 has a thickness d3 set to 0.30 [mm], and the side wall of the second case member 50 has a thickness d4 set to 0.75 [mm]. These numerical values are examples, and the present invention is not limited to these numerical values from the gist thereof, and the respective widths and thicknesses are appropriately determined from the viewpoints of weight reduction and target bending strength.

<< Effects of battery pack in this embodiment >>
As described above, in the present embodiment, the lengths in the longitudinal direction (length in the Y-axis direction) L4 and L5 of both the first case member 40 and the second case member 50 are set to be the same. Between the cell 17 end of the cell 17, 18 of the battery unit 20 not facing the circuit board 19 and the inner surface of the side wall 54 facing the cell 17 end of the second case member 50. Is provided with a small space 55, extended from one side wall 54 of the second case member 50 toward the opposite side wall 54 and supporting the circuit board 19 of the battery unit 20 together with the inner side surface of the bottom of the first case member 40. The second case member 50 includes a shelf 60 and connects the inner main surface of the one side wall 54 of the second case member 50 to the bottom main surface of the second case member 50 of the support shelf 60. Reinforcing rib reaching the bottom 0 is extended in the direction connecting the support shelf 60 and the case bottom surface 52, that is, in the case member 40, 50 butting direction (Z-axis direction). The bending strength of the one side wall 54 can be improved.

  Therefore, in the present embodiment, the one side wall 54 of the second case member 50 is located on the outer side of the case 30 or the inner side of the case 30 when an impact is applied to the case 30 as compared with the configuration disclosed in Patent Document 1. It is possible to prevent the case 30 from being destroyed, mainly the circuit board 19 from being destroyed, and the case 30 from being opened.

  For example, when an impact is applied to the one side wall from the outside of the case 30 in the direction perpendicular to the main surface, the reinforcing rib 70 is provided, so that compared to the case where the reinforcing rib 70 is not provided, The bending strength of the one side wall is improved, and the one side wall can be prevented from being bent inward of the case 30. Further, when an impact is applied to the bottom of each case member 40, 50 from the outside in a direction perpendicular to the bottom main surface, the reinforcing rib 70 is provided, so the reinforcing rib 70 is not provided. As compared with the case, the bending strength of the one side wall is improved, and the one side wall can be prevented from being bent outward from the case 30.

  In the present embodiment, the reinforcing rib 70 is extended while increasing in thickness, that is, gradually increasing from the bottom main surface of the second case member 50 to the bottom surface 52 of the second case member 50 in the support shelf 60. Therefore, compared with the case where the reinforcing rib having the same and uniform width as the width of the reinforcing rib 70 on the support shelf 60 (opening 51) side is provided, the reinforcing rib itself can be prevented from being bent, and The effect of suppressing the destruction of the case 30 and the effect of suppressing the case opening can be improved.

In the present embodiment, the width of the rib is changed. However, the present invention is not limited to this, and the case storage effect destruction suppressing effect and the case opening suppressing effect can be expected even when the rib width is uniform. However, as described above, when the rib width is changed, it is possible to further suppress the deflection of the reinforcing ribs themselves, and it is possible to improve the case stored article destruction suppressing effect and the case opening suppressing effect.
In the present embodiment, the reinforcing rib 70 is stretched while increasing its width, that is, gradually increasing from the bottom main surface of the second case member 50 to the bottom surface 52 of the second case member 50 in the support shelf 60. However, it is not limited to this, and even if the width of the support shelf 60 is reduced, that is, gradually reduced as it approaches the bottom surface 52 of the second case member 50 from the bottom main surface of the second case member 50, the rib itself It is possible to exert a bending suppressing action and to exert a similar effect.

[Embodiment 2]
FIG. 3 is a schematic arrow view of the second case member of the battery pack according to the present embodiment, and is an arrow view of the second case member as viewed from the direction A as in FIG.
In the present embodiment, the configuration of the reinforcing rib 73 provided on the second case member 50 is only different from that of the first embodiment, and the other configurations are the same as those of the first embodiment, and thus description thereof is omitted. To do.

  As shown in FIG. 3, in the present embodiment, the case members 40, 50 have a plurality of vertical ribs 71 that divide the small space 55 from the support shelf 60 toward the bottom of the second case member 50. It is extended | stretched in the butt | matching direction (Z-axis direction). And the horizontal rib 72 is extended in the short direction (X-axis direction) of the case 30 so as to penetrate the plurality of vertical ribs 71, in other words, in parallel with the bottom of the second case member 50, It arrange | positions so that the side walls of the 2nd case member 50 arranged in parallel in the direction along the bottom face 52 of 2 case members 50 may be connected.

  Specifically, in the second case member 50, on one side wall 54 described in the first embodiment, that is, on the inner side surface of the side wall 54 facing the end of the cell 17 not facing the circuit board 19, From the support shelf 60 to the bottom of the second case member 50, lattice-like reinforcing ribs 73 in which the vertical ribs 71 and the horizontal ribs 72 are orthogonal to each other are erected so as to partition the small space 55. Both the vertical ribs 71 and the horizontal ribs 72 have a uniform width.

In the present embodiment, the horizontal ribs 72 are arranged so as to penetrate the center of the plurality of vertical ribs 71. The arrangement position of the horizontal rib 72 is not limited to this, and in view of the thickness of the support shelf 60 and the bottom of the second case member 50, etc. Direction).
The widths of both the vertical rib 71 and the horizontal rib 72 are set to, for example, 0.25 [mm]. This numerical value is an example, and the present invention is not limited to this numerical value from the gist thereof, and the width is appropriately determined from the viewpoint of weight reduction, target bending strength, and the like.

<< Effects of battery pack in this embodiment >>
As described above, in the present embodiment, the vertical rib 71 extends in the Z-axis direction so as to reach the bottom of the second case member 50 from the support shelf 60 and divide the small space 55. The lateral ribs 72 are arranged extending in the X-axis direction so as to connect the side walls arranged in the short direction (X-axis direction) of the second case member 50 and penetrate the plurality of vertical ribs 71. When the impact is applied to the case 30, the lateral rib 72 can suppress the bending of the vertical rib 71 having a uniform width. Compared with the configuration of the first embodiment, when the impact is applied to the case 30, 2 The effect of suppressing the one side wall 54 of the case member 50 from being bent outward or inward of the case 30 can be improved, and the case 30 contents, mainly the circuit board 19 can be destroyed. The suppression effect can be improved and the case 30 is opened. It can improve the effect of suppressing.

In the present embodiment, by adopting the above configuration, the thickness of the vertical rib 71 arranged so as to reach the bottom of the second case member 50 from the support shelf 60 and divide the small space 55 is made uniform. Moreover, compared with Embodiment 1, the said case storage thing destruction inhibitory effect and the said case opening inhibitory effect can be improved.
When the configuration of the first embodiment is adopted, the width of the extending end of the reinforcing rib 70 on the bottom side of the second case member 50 is made larger than the extending end on the support shelf 60 side. When the second case member is molded by pouring, sink marks occur on the outer main surface of the bottom of the second case member 50 corresponding to the bottom-side extending end of the second case member 50 of the reinforcing rib 70. There is. When sink marks occur, the second case member 50 is treated as a defective product because it is not preferable in appearance, and as a result, the yield of the battery pack 100 decreases.

In the present embodiment, as compared with the first embodiment, the thickness of the vertical rib 71 is made uniform with the same thickness as the smaller one, so that the sink mark is formed on the outer main surface at the bottom of the second case member 50. Can be suppressed, and the yield can be improved.
In the present embodiment, the vertical rib 71 and the horizontal rib 72 are orthogonal to each other. However, the present invention is not limited to this, and the vertical rib 71 has an acute angle with respect to the horizontal rib 72 parallel to the bottom of the second case member 50, or In other words, when the obtuse angle is crossed, in other words, even when the gap between the adjacent vertical ribs 71 gradually increases or decreases gradually from the support shelf 60 toward the bottom of the second case member 50, the above effect is exhibited. be able to.

[Embodiment 3]
FIG. 4 is an arrow view of the second case member of the battery pack according to the present embodiment, and is an arrow view of the second case member as viewed from the direction A as in FIG.
In the present embodiment, only the configuration of the reinforcing rib provided on the second case member is different from that of the first embodiment, and the other configurations are the same as those of the first embodiment, and thus the description thereof is omitted.

  As shown in FIG. 4, in the present embodiment, in the other case member 50, the side walls arranged in parallel in the short direction (X-axis direction) from the support shelf 60 to the bottom of the second case member 50. A lateral rib 75 parallel to the bottom surface 52 is provided on the inner main surface of the one side wall 54 described in the first embodiment, and a plurality of rib elements 74 and 76 are provided on the lateral rib 75. The inner side main surface of the one side wall 54 is continuously provided so as to reach.

In the present embodiment, the first rib element 76 and the second rib element 74 are not arranged on the same axis in the abutting direction (Z-axis direction) of the case members 40, 50, and The two rib elements 74 and the first rib elements 76 intersect with each other in a shifted state.
Specifically, the first rib element 76 and the lateral rib 75 are orthogonal to the inner surface of the one side wall 54 of the second case member 50 from the support shelf 60 to the bottom of the second case member 50. In addition, grid-like reinforcing ribs 77 in which the second rib elements 76 and the lateral ribs 75 are orthogonal to each other are erected so as to divide the small space 55.

  Each of the second rib element 74, the lateral rib 75, and the first rib element 76 has a uniform width. Since the second rib element 74 and the first rib element 76 are arranged so as to be shifted from each other in the Z-axis direction, as shown in FIG. 4, the case members 40 and 50 are impacted in the butting direction (Z-axis direction). When added, the lateral rib 75 can bend, and the impact is absorbed by the bending of the lateral rib 75.

  In the present embodiment, the distance L1 between the second rib element 74 and the first rib element 76 in the X-axis direction is set equal, but the distance L1 is not limited to this, and from the viewpoint of the target bending strength and the like. It can be determined as appropriate. For example, when an impact is applied in the case member 40, 50 butting direction (Z-axis direction), the side wall receives the impact in the vicinity of the side wall juxtaposed in the X-axis direction of the second case member 50. As the two case members 50 approach the center in the X-axis direction, the tendency of the support shelf 60 or the bottom of the second case member 50 to bend due to the impact increases. Therefore, by arranging these so as to reduce the distance L1 in the X-axis direction between the second rib element 74 and the first rib element 76 as approaching the center, the bending of the lateral rib 75 can be suppressed, and the amount of bending Can be adjusted as appropriate.

When the distance L1 between the second vertical rib element 74 and the first vertical rib element 76 in the X-axis direction is reduced, if the distance L1 is excessively reduced, the above-described bending of the lateral rib 75 may not be generated. . If the distance L1 is set to be equal to or larger than the widths of the second vertical rib element 74 and the first vertical rib element 76, the above-described bending of the horizontal rib 75 can be caused.
In the present embodiment, the lateral rib 75 is disposed just between the support shelf 60 and the second case member 50. The arrangement position of the lateral rib 75 is not limited to this, and in the vertical direction (Z-axis direction) as appropriate from the viewpoint of the target bending strength and the like in view of the thickness of the support shelf 60 and the thickness of the bottom of the second case member 50 and the like. Can be moved.

The widths of the second vertical rib element 74, the horizontal rib 75, and the first vertical rib element 76 are set to, for example, 0.25 [mm]. This numerical value is an example, and the present invention is not limited to this numerical value from the gist thereof, and the width is appropriately determined from the viewpoint of weight reduction, target bending strength, and the like.
<< Effects of battery pack in this embodiment >>
As described above, in the present embodiment, in the second case member 50, the side wall 54 that faces the end of the cell 17 where the circuit board 19 is not disposed, specifically, the inner surface of the one side wall 54. The second vertical rib element is a lattice-shaped reinforcing rib 77 that is erected on the grid, the second vertical rib element 74 and the horizontal rib 75 are orthogonal to each other, and the first vertical rib element 76 and the horizontal rib 75 are orthogonal to each other. 74 and the first vertical rib element 76 are not arranged on the same axis, and are extended in the Z-axis direction in a state of being shifted from each other. When an impact is applied in the (Z-axis direction), the lateral rib 75 can be bent to absorb the impact.

Therefore, in the present embodiment, when compared with the first and second embodiments, when the impact is applied to the first case member 40 in the negative direction of the Z axis, the lateral rib 75 is connected to the Z axis via the support shelf 60. The support shelf 60 and the lateral rib 75 both sink in the negative direction of the Z-axis, and the impact transmitted to the circuit board 19 can be alleviated and the breakage thereof can be suppressed.
Further, in the present embodiment, compared to the first and second embodiments, when an impact is applied to the second case member 50 in the positive direction of the Z axis, the lateral rib 75 is bent in the positive direction of the Z axis. Thus, the impact transmitted to the support shelf 60 can be reduced, the impact transmitted to the circuit board 19 can be reduced, the destruction of the circuit board 19 can be suppressed, and the failure of the battery pack can be reduced.

In addition, in the present embodiment, when an impact is applied to the case 30 in the negative direction of the Z-axis compared to the first and second embodiments, the impact is less likely to be transmitted to the bottom of the second case member 50. Therefore, whitening due to plastic deformation at the bottom corresponding to the arrival point of the second vertical rib element 74 can be suppressed.
Further, since the lateral rib 75 is bent, it is possible to suppress an impact from being transmitted to the cells 17 and 18 contained in the case 30 and to suppress failure of the cells 17 and 18.

  When the configuration of the second embodiment is adopted, the vertical ribs 71 and the horizontal ribs 72 intersect each other to form a point gathered from four sides, and when the second case member 50 is molded by pouring the molten member into the mold, the reinforcement On the side wall 54 of the second case member 50 on which the rib 73 is erected, sink marks may occur on the outer main surface corresponding to the set point. When sink marks occur, the second case member 50 is treated as a defective product because it is not preferable in appearance, and as a result, the yield of the battery pack 100 decreases.

  In the present embodiment, the intersection of the second rib element 74 and the lateral rib 75 does not coincide with the intersection of the first rib element 76 and the lateral rib 75, and is shifted, so that the points gathered from three directions are Arise. Therefore, in the present embodiment, when the second case member 50 is molded by pouring the molten member into the mold, the number of paths that intersect at the above-mentioned gathering point in the mold is reduced by one as compared with the second embodiment. The occurrence of sink marks can be suppressed, and the yield can be improved.

<Variation in Embodiment 3>
FIG. 5 is a schematic arrow view of a variation of the second case member of the battery pack according to the third embodiment.
In the third embodiment, the first rib element 76, the second rib element 74, and the lateral rib 75 are orthogonal to each other as shown in FIG. 4, but the present invention is not limited to this, and in this variation, as shown in FIG. When the first rib element 80 and the second rib element 78 intersect at an acute angle or an obtuse angle with respect to the lateral rib 79 parallel to the bottom of the second case member 50, in other words, the adjacent first rib element Even when the gap between 80 and the adjacent second rib elements 78 gradually increases or decreases from the support shelf 60 toward the bottom of the second case member 50, the above effect can be exhibited.

Of course, only one of the adjacent first rib elements 80 or the adjacent second rib elements 78 gradually increases or decreases the gap, and the other is parallel to the thickness direction (Z-axis direction) of the case 30. May be.
<Others>
In view of the bending action of the lateral rib 75 described in the effect in the third embodiment, when the configuration of the reinforcing rib 77 shown in the third embodiment is applied to the other inner surface of the case, the impact is applied to the case. When the case is added, it is possible to prevent the case 30 from being bent by moderately bending without excessively bending the case 30 and to prevent the case members attached to each other from being detached. It is possible to prevent the case 30 from opening.

  In view of the configuration exemplified in each of the above embodiments, the reinforcing ribs 70, 73, of the second case member 50 in the case 30 are premised on the size reduction of the circuit board 19 (reduction in the length in the Z-axis direction). It is preferable that the side wall 54 provided with 77 and 81 is larger in the Z-axis direction because the effect of suppressing the deflection of the side wall 54 can be improved.

  The present invention can be widely applied to the field of battery packs. According to the present invention, even if the impact applied from the outside, such as dropping, increases, the destruction of the case contents is suppressed and the case opens. Since it can suppress, it can contribute to the safety | security improvement of a battery and the industrial applicability is very large.

(A) is an exploded perspective view of the battery pack according to Embodiment 1, and (b) is a schematic cross-sectional view of the battery pack according to the present embodiment. 4 is a schematic arrow view of a second case member of the battery pack according to Embodiment 1. FIG. 6 is a schematic arrow view of a second case member of a battery pack according to Embodiment 2. FIG. 6 is a schematic arrow view of a second case member of a battery pack according to Embodiment 3. FIG. 6 is a schematic arrow view of a variation of a second case member of a battery pack according to Embodiment 3. FIG.

Explanation of symbols

13 Closed gap 14, 15 Lead plate 16 Double-sided adhesive tape 17, 18 Unit cell (cell)
19 circuit board 20 battery unit 30 case 40 first case member 41, 51 opening 42, 52 bottom surface 50 second case member 53 rib 54 side wall 55 space 60 support shelf 70, 73, 77, 81 reinforcing rib 71 vertical rib 72, 75, 79 Horizontal ribs 76, 80 First rib elements 74, 78 Second rib elements

Claims (7)

In the case housing, a plurality of unit cells are accommodated in a stacked state in the unit cell storage space, and the battery is charged and discharged so as to face one end surface of any one unit cell except for the lowermost unit cell. The circuit board to be controlled is stored along the inner surface of the case,
A support shelf that supports the lower end edge of the circuit board is projected from the inner surface of the case behind the circuit board to the unit cell side, and directly below the support shelf, the other battery cell end surface, and the case inner surface A battery pack in which reinforcing ribs are disposed from the support shelf to the bottom surface of the case in a space surrounded by. The case housing is formed by joining a pair of rectangular parallelepiped case members at each other opening,
2. The battery pack according to claim 1, wherein the reinforcing rib is disposed so as to intersect the virtual plane when a virtual plane passing through the periphery of the opening is assumed.   The pack according to claim 1 or 2, wherein a plurality of the reinforcing ribs are formed from the support shelf toward the bottom surface of the case, and the reinforcing ribs of the respective strips become wider as they approach the bottom surface of the case. battery.   3. The battery pack according to claim 1, wherein the reinforcing rib is a combination of a vertical rib extending from the support shelf toward the bottom surface of the case and a horizontal rib intersecting the vertical rib. The reinforcing ribs reach the first rib element from the support shelf toward the case bottom, the second rib element from the case bottom toward the support shelf, and both the first rib element and the second rib element. Combining with horizontal ribs,
3. The battery pack according to claim 1, wherein the first rib element and the second rib element arrive in a state of being shifted from each other with respect to the lateral rib. In the case housing, two rectangular unit cells are stored in the unit cell storage space, and the circuit board is stored along the inner side surface of the case so as to face an end surface of one unit cell.
A support shelf that supports the lower end edge of the circuit board is extended from the inner surface of the case behind the circuit board in a direction approaching the unit cell, and the other unit cell end surface directly below the support shelf and the case The battery pack according to any one of claims 1 to 5, wherein a reinforcing rib is continuously provided in a space surrounded by the inner side surface from the support shelf to the bottom surface of the case. A unit cell is stored in the case,
Reinforcing ribs are disposed from one main surface to the other main surface at least on the side wall surrounding the inner main surface of the case,
The reinforcing rib includes a first rib element extending from the one main surface toward the other main surface, a second rib element extending from the other main surface toward the one main surface, the first rib element, and the It consists of a combination with a lateral rib that both second rib elements reach,
The battery pack in which the first rib element and the second rib element arrive in a state of being shifted from each other with respect to the lateral rib.

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