JP6613773B2 - Power storage device - Google Patents

Description

  The present invention relates to a power storage device in which a plurality of power storage elements including a non-aqueous electrolyte secondary battery such as a lithium ion secondary battery are modularized.

  2. Description of the Related Art Conventionally, a power storage device (assembled battery) in which a plurality of rectangular power storage elements (unit cells) are stacked and external terminals of the power storage elements are connected via a bus bar is known. Note that this type of power storage device is disclosed in various documents including Patent Document 1.

  In this type of power storage device, a cap made of an insulating material may be attached to each power storage element so as to cover the external terminal. Thereby, the contact and short circuit between an external terminal and peripheral members, such as an electric wire, are prevented.

  Further, in this case, a protrusion may be provided on the upper surface of the cap, and the protrusion is inserted into a hole in the top plate arranged above the energy storage element, so that the energy storage element is placed through the cap. It can be positioned and held on a plate.

  In general, the surface of the rectangular storage element is formed between a rectangular terminal surface portion provided with a pair of external terminals, a rectangular bottom surface portion disposed on the opposite side of the terminal surface portion, and the long sides of the terminal surface portion and the bottom surface portion. And a pair of short side surfaces connecting the short sides of the terminal surface portion and the bottom surface portion. The pair of external terminals are provided in the vicinity of both ends in the longitudinal direction of the terminal surface portion, and a cap having a peripheral wall facing the outside of the pair of long side surface portions and one short side surface portion of each power storage element is attached to each external terminal. The

JP2015-122337A

  However, when the cap attached to the rectangular electricity storage element as described above is positioned only from one side by one short side surface portion of the electricity storage element in the longitudinal direction of the terminal surface portion, the cap of the electricity storage element rattles. Is likely to occur.

  Therefore, in the manufacture of the power storage device, when a cap is attached to the power storage element positioned at a predetermined position, and when a holder such as a top plate is attached via the cap, positioning is uncertain. The holding body may not be smoothly attached to the cap.

  In view of the above, an object of the present invention is to provide a power storage device that can suppress rattling of a cap that covers an external terminal of a power storage element.

The present invention
A storage element having a rectangular terminal surface portion, an external terminal provided on the terminal surface portion, and a short side surface portion continuous with a short side of the terminal surface portion;
A cap that covers the external terminal;
An engaged portion is provided on the terminal surface portion,
The cap includes a first pressing portion that is pressed against the short side surface portion from one side in the longitudinal direction of the terminal surface portion, and a second pressing portion that is pressed against the engaged portion from the other side in the longitudinal direction of the terminal surface portion. A power storage device is provided.

  The “cap” referred to in the present specification may be provided individually for each external terminal, or may be an integrated unit of a plurality of covering portions covering each external terminal.

  According to the above power storage device, when the cap covering the external terminal is attached to the power storage element, the first pressing portion of the cap is pressed against the short side surface portion of the power storage element from one side in the longitudinal direction of the terminal surface portion. When the second pressing portion is pressed against the engaged portion of the terminal surface portion from the other side in the longitudinal direction of the terminal surface portion, rattling of the cap with respect to the power storage element is suppressed in the longitudinal direction of the terminal surface portion. Accordingly, when the power storage element is held by the holding body such as the top plate via the cap, the holding body can be smoothly attached to the cap that is reliably positioned with respect to the power storage element.

  The cap may include a peripheral wall portion that surrounds the external terminal, and a protruding piece that protrudes outward from the peripheral wall portion, and the second pressing portion may be provided at a distal end portion of the protruding piece. .

  In this case, in a state where the protruding piece of the cap is bent, the second pressing portion provided at the tip of the protruding piece is engaged with the engaged portion of the terminal surface portion, thereby being engaged by the second pressing portion. Since the elastic force of the protruding piece can be applied to the pressing portion, the cap can be firmly fixed in the longitudinal direction of the terminal surface portion.

  When a sensor attachment portion for attaching a sensor is provided on the terminal surface portion, a gap may be formed between the peripheral wall portion and the second pressing portion in the cap, and the gap extends from the sensor. You may be made into the opening for letting an electric wire pass.

  In this case, since the electric wire extending from the sensor attached to the terminal surface portion can be arranged so as to pass through the opening formed between the peripheral wall portion of the cap and the second pressing portion, the degree of freedom of wiring of the electric wire is increased. improves.

  The sensor mounting portion and the opening may be arranged side by side in the short direction of the terminal surface portion.

  In this case, since the electric wires can be routed so as to extend from the sensor in the short direction of the terminal surface portion, various electric wires such as a safety valve provided on the terminal surface portion can be obtained by reducing the electric wire portion passing over the terminal surface portion. The wear of the electric wire due to the contact with the metal parts or the terminal surface itself can be suppressed. In addition, since the electric wire is led from the sensor to the long side of the terminal surface at the shortest distance, the electric wire can be shortened depending on the electrical component and the electric wire layout.

  The peripheral wall portion of the cap may have an opposing wall portion facing the short side surface portion, and the first pressing portion may be a protrusion provided on the inner surface of the opposing wall portion.

  In this case, since the protruding portion as the first pressing portion is interposed between the short side surface portion of the energy storage device and the opposing wall portion of the cap, the presence or absence of expansion of the energy storage device and the presence or absence of dimensional error of the energy storage device and the cap Regardless of this, the protrusion can be securely adhered to the short side surface. Thereby, a cap can be fixed more firmly regarding the longitudinal direction of a short side part.

  When one axial side of the peripheral wall portion of the cap is open, the protrusion may be formed in a rib shape extending in the axial direction.

  In this case, when the cap is inserted into the electricity storage element along the axial direction from the opening side of the peripheral wall portion, the rib-shaped protrusion provided in the inner surface of the opposing wall portion of the cap and extending in the axial direction, Since the friction generated between the short side surface portion of the element is reduced, the cap can be smoothly attached to the power storage element.

  The protruding portion may have a tapered shape in which a protruding height gradually decreases toward the one side in the axial direction.

  In this case, when the cap is inserted into the power storage element as described above, the protrusion height of the portion that starts to hit the short side surface portion of the power storage element in the protrusion portion is low, so that the protrusion is more effectively caught on the short side surface portion. Can be reduced. Moreover, since the high adhesiveness is obtained with respect to the short side surface portion in the portion where the protruding height of the protruding portion is high, the cap can be firmly fixed to the power storage element.

  When the power storage element has a first long side surface portion that is continuous with one long side of the terminal surface portion and a second long side surface portion that is continuous with the other long side of the terminal surface portion, the cap is formed on the terminal surface portion. A third pressing portion that is pressed against the first long side surface portion from one side in the short side direction; and a fourth pressing portion that is pressed against the second long side surface portion from the other side in the short side direction of the terminal surface portion. May be.

  In this case, the third pressing portion and the fourth pressing portion of the cap are pressed against the first long side surface portion and the second long side surface portion of the electricity storage device, respectively, so that the cap is placed in the short direction of the terminal surface portion with respect to the electricity storage device. Can also be fixed. Therefore, the shakiness of the cap with respect to the power storage element can be more reliably suppressed.

  Preferably, the power storage device according to the present invention includes a holding body that holds the power storage element via the cap.

  Accordingly, the cap can be interposed between the power storage element and the holding body to prevent the short circuit, and the power storage element can be positioned and held by the holding body. In addition, since the cap is reliably positioned with respect to the power storage element as described above, the positioning accuracy of the power storage element with respect to the holding body is improved. In addition, the rigidity of the power storage device is increased by suppressing the backlash of the power storage element with respect to the holding body.

  ADVANTAGE OF THE INVENTION According to this invention, the shaki with respect to the electrical storage element of the cap which covers the external terminal of an electrical storage element can be suppressed.

The disassembled perspective view of the assembled battery which concerns on embodiment of this invention. The perspective view which looked at the assembled battery from the upper part. The perspective view which looked at the assembled battery from the downward direction. The disassembled perspective view which shows a heat shield and its peripheral part. The top view which shows the connection between single cells. The exploded perspective view of a cell and peripheral parts. The perspective view of the cell by which the peripheral component was assembled | attached. The perspective view which looked at the upper cap from the upper part. The perspective view which looked at the upper cap from the lower part. XX sectional drawing of FIG. 2 which shows an upper cap and its peripheral part. The XI-XI sectional view taken on the line of FIG. 2 which shows an upper cap and its peripheral part. XII-XII sectional view taken on the line of FIG. 11 which shows an upper cap and its peripheral part. The XIII-XIII sectional view taken on the line of FIG. 11 which shows an upper cap and its peripheral part. The perspective view which looked at the lower cap from the upper part. The perspective view which looked at the lower cap from the lower part. Sectional drawing which looked at the lower cap and its peripheral part from the transversal direction of the cell. Sectional drawing which looked at the lower cap and its peripheral part from the longitudinal direction of the cell.

  Embodiments according to the present invention will be described below with reference to the accompanying drawings. In the following description, terms indicating specific directions and positions as necessary (for example, terms including “up”, “down”, “right”, “left”, “side”, “end”) are used. However, the use of these terms is to facilitate understanding of the invention with reference to the drawings, and the technical scope of the present invention is not limited by the meaning of these terms. That is, these terms indicate directions in the posture of the power storage device shown in the attached drawings, and do not necessarily coincide with directions in an actual use state. Further, the following description is merely illustrative in nature and is not intended to limit the present invention, its application, or its use.

  1 to 4 show an assembled battery (battery module) 1 as a power storage device according to an embodiment of the present invention. The assembled battery 1 includes, for example, 12 rectangular unit cells (battery cells) 2 and a holding body 40 that holds these unit cells 2. The unit cell 2 is a nonaqueous electrolyte secondary battery such as a lithium ion secondary battery, for example.

  Referring to FIGS. 6 and 7, each single battery 2 includes a battery container 3 that contains an electrolytic solution and an electrode body, and a lid 5 that seals an opening on the upper end side of the battery container 3.

  The battery case 3 in the present embodiment includes a rectangular bottom surface portion 3a and side walls 3b, 3c, 3d, 3e extending upward from the periphery of the bottom surface portion 3a. The side wall rises from the long side portion of the bottom surface portion 3a and opposes the first and second long side surface portions 3b and 3c, and has a smaller area than the long side surface portions 3b and 3c, and the short side portion of the bottom surface portion 3a. 1st and 2nd short side surface parts 3d and 3e which stand up from and oppose each other.

  The lid 5 is also generally rectangular, and the battery container 3 and the lid 5 constitute a flat rectangular parallelepiped exterior body. The outer periphery of the side walls 3b to 3e of the battery container 3 is covered with an insulating sheet (not shown).

  Positive and negative external terminals 7A and 7B are provided at both ends in the longitudinal direction of the lid 5. The external terminals 7A and 7B are bolt terminals, and are attached to the lid body 5 via packings 9A and 9B so that the shaft portions 7a and 7b face upward. The packings 9A and 9B are electrically connected to the heads (not shown) of the external terminals 7A and 7B and the electrode bodies (not shown) in the battery container 3 through current collectors (not shown). The connected connecting rods 10A and 10B are accommodated.

  The shafts 7a and 7b of the external terminals 7A and 7B are penetrated at one end of the connection rods 10A and 10B, and the narrow inspection terminal portions 10a and 10b are provided at the other ends of the connection rods 10A and 10B. It has been.

  The external terminals 7A and 7B are electrically connected to external terminals 7A and 7B having different polarities in another unit cell 2 through the bus bar 14. The bus bar 14 is a plate-like conductive member extending linearly, and through holes 14 a and 14 b are provided at both ends of the bus bar 14. In the bus bar 14, one through hole 14a has a larger diameter than the other through hole 14b.

  One through hole 14a, 14b of the bus bar 14 is inserted into the shaft portions 7a, 7b of the external terminals 7A, 7B, and the nut 11 screwed into the shaft portions 7a, 7b from the upper side of the bus bar 14 is tightened. One end of 14 is fixed to the external terminals 7A and 7B.

  As shown in the schematic diagram of FIG. 5, twelve unit cells 2 constituting the assembled battery 1 are arranged in two rows. The six unit cells 2 constituting each row are arranged so that the long side surfaces 3b, 3c of the battery containers 3 of the adjacent unit cells 2 face each other. The unit cells 2 belonging to one row and the unit cells 2 belonging to the other row are arranged adjacent to each other so that the short side surfaces 3d and 3e face each other.

  The twelve unit cells 2 are arranged so that the polarities of the external terminals 7A and 7B adjacent to each other in the longitudinal direction and the short direction of the lid 5 are different from each other. Adjacent external terminals 7 </ b> A and 7 </ b> B are electrically connected by the bus bar 14, so that the 12 cell units 2 are connected in series.

  Of the two rows of the unit cells 2, the positive electrode external terminal 7 </ b> A of the unit cell 2 arranged on one end side (left side of FIG. 5) of one row (upper row in FIG. 5) is bent in an L shape. One end of the bus bar 15A is fixed by the nut 11, and the positive external terminal 17A of the assembled battery 1 is provided at the other end of the bus bar 15A. One end portion of a bus bar 15B bent in an L shape is fixed to the negative electrode external terminal 7B of the unit cell 2 arranged on the other end side (right side in FIG. 5) of the same row by a nut 11, and the other of the bus bar 15B. The negative electrode external terminal 17B of the assembled battery 1 is provided at the end. The external terminals 17A and 17B of the assembled battery 1 are constituted by, for example, bolt-shaped terminals integrated with the bus bars 15A and 15B.

  As shown in FIGS. 6 and 7, a pair of upper cap 20 and one lower cap 30 are attached to each unit cell 2. The upper cap 20 and the lower cap 30 are made of a resin such as polypropylene resin, for example.

  The upper cap 20 is attached to the upper end side of the battery container 3 of the unit cell 2 so as to cover the external terminals 7A and 7B of the unit cell 2. Of the 24 external terminals 7A and 7B of the 12 unit cells 2 constituting the assembled battery 1, the external terminals 7A and 7B to which the bus bars 15A and 15B having the external terminals 17A and 17B of the assembled battery 1 are fixed are excluded. The remaining 22 external terminals 7A and 7B are each covered by one upper cap 20. The upper cap 20 includes a top wall portion 21 disposed above the external terminals 7 </ b> A and 7 </ b> B of the unit cell 2, and a cylindrical upper convex portion 22 protruding upward from the top wall portion 21.

  The lower cap 30 is attached to the lower end side of the battery container 3 so as to cover the bottom surface portion 3 a of the battery container 3 of the unit cell 2. One lower cap 30 is attached to every single cell 2 constituting the assembled battery 1. The lower cap 30 includes a bottom wall portion 31 disposed below the bottom surface portion 3 a of the battery container 3 of the unit cell 2, and a cylindrical lower convex portion 32 protruding downward from the bottom wall portion 31.

  More specific configurations of the upper cap 20 and the lower cap 30 will be described later.

  As shown in FIGS. 1 to 4, the twelve unit cells 2 are arranged in two rows as described above, and a heat shield plate 70 (see particularly FIG. 4) is provided between the adjacent unit cells 2 in each row. It is hold | maintained at the holding body 40 so that it may be interposed.

  The holding body 40 includes a top plate 41 as a first holding portion and a bottom plate 47 as a second holding portion for holding the unit cell 2 to which the upper cap 20 and the lower cap 30 are mounted in the vertical direction in the drawing. . Furthermore, the holding body 40 includes a pair of side plates 45 and 46 that connect the top plate 41 and the bottom plate 47. A monitoring device 60 having a control board (not shown) is attached to one side plate 46.

  The top plate 41 has an integral structure in which a metal plate is formed into a generally rectangular shape by press molding or the like. The top plate 41 is formed with a plurality of circular through holes 42 into which the upper convex portions 22 of the upper cap 20 are fitted so as to penetrate in the thickness direction. The top plate 41 is provided with the same number of through holes 42 as the upper cap 20, and each through hole 42 is formed at a position corresponding to the upper convex portion 22 of the upper cap 20.

  A plurality of ventilation openings 43 are formed in the top plate 41 so as to penetrate in the thickness direction. The openings 43 are arranged in two rows along the rows of the cells 2. The opening 43 is arranged above the gap between the adjacent unit cells 2. The shape of the opening 43 is, for example, an ellipse along the longitudinal direction of the battery container 3 of the unit cell 2 in plan view (hereinafter also simply referred to as “the longitudinal direction of the unit cell 2”).

  Of the four corner portions of the top plate 41, the two corner portions corresponding to the external terminals 7A and 7B connected to the external terminals 17A and 17B of the battery pack 1 via the bus bars 15A and 15B include these external terminals. Cutout portions 41a and 41b for exposing 7A and 7B are provided. Terminal covers 52A and 52B that cover the corresponding external terminals 7A and 7B can be attached to and detached from the notches 41a and 41b.

  The bottom plate 47 has an integral structure in which a metal plate is formed into a generally rectangular shape by press molding or the like. The bottom plate 47 is formed with a plurality of circular through holes 48 into which the lower protrusions 32 of the lower cap 30 are fitted so as to penetrate in the thickness direction. Each through hole 48 is formed at a position corresponding to the lower convex portion 32 of the lower cap 30.

  A plurality of ventilation openings 49 are formed in the bottom plate 47 so as to penetrate in the thickness direction. The openings 49 are arranged in two rows along the row of the cells 2. The opening 49 is disposed below the gap between the adjacent unit cells 2 and below one end of each row of the unit cells 2. The shape of the opening 49 is, for example, an elongated rectangular shape along the longitudinal direction of the unit cell 2.

  The side plates 45 and 46 have an integral structure in which a metal plate is formed into a generally rectangular shape by press molding or the like. The upper ends of the side plates 45 and 46 are connected to the top plate 41 by screwing, and the lower ends of the side plates 45 and 46 are connected to the bottom plate 47 by screwing. The side plates 45 and 46 include a plurality of slots 45a and 46a into which end portions of the heat shield plate 70 are inserted. Each slot 45a, 46a is formed to extend in the vertical direction at a position corresponding to the gap between the adjacent unit cells 2.

  As shown in FIG. 4, the heat shield plate 70 is an elongated plate material extending in a direction perpendicular to the side plates 45 and 46, and is disposed in parallel to the long side surfaces 3 b and 3 c of the unit cell 2. The both ends 71 and 72 of the heat shield plate 70 are reduced in width in the vertical direction by providing notches at the upper and lower corners. The heat shield plate 70 is held across the side plates 45 and 46 by inserting both ends 71 and 72 into the slots 45 a and 46 a of the side plates 45 and 46. Thereby, the heat shield plate 70 is disposed so as to cross the two rows of the cells 2.

  The heat shield plate 70 is integrally provided with a pair of projecting portions 73 and 74 projecting upward. Parts other than the protrusions 73 and 74 in the heat shield plate 70 are disposed below the upper end of the battery container 3 of the unit cell 2, and the protrusions 73 and 74 protrude above the upper end of the battery container 3. Be placed. A guide member 78 through which an electric wire connected to a sensor such as a temperature sensor 80 (see FIG. 13) is attached is attached to the upper ends of the protrusions 73 and 74.

  The lower end of the heat shield plate 70 is disposed above the upper end of the lower cap 30, thereby avoiding interference between the heat shield plate 70 and the lower cap 30. The protrusions 73 and 74 of the heat shield plate 70 are disposed between the pair of upper caps 20 in the longitudinal direction of the unit cell 2, and the upper ends of the heat shield plates 70 other than the protrusions 73 and 74 are the upper cap 20. It is arranged below the lower end. Thereby, interference with the heat shield 70 and the upper cap 20 is avoided.

  Referring to FIGS. 1 to 3, the upper cap 20 attached to the upper end side of the unit cell 2 has an upper convex portion 22 fitted in a through hole 42 of the top plate 41 and a top wall portion 21 of the top plate 41. It is in contact with the lower surface. On the other hand, in the lower cap 30 attached to the lower end side of the unit cell 2, the lower convex portion 32 is fitted in the through hole 48 of the bottom plate 47, and the bottom wall portion 31 is in contact with the upper surface of the bottom plate 47. The top plate 41 and the bottom plate 47 are connected to each other by the side plates 45 and 46 in a state where the 12 unit cells 2 are sandwiched and held via the upper cap 20 and the lower cap 30. Thus, the twelve unit cells 2 are held from the side of the external terminals 7A and 7B by the top plate 41 via the upper cap 20 and from the side opposite to the external terminals 7A and 7B by the bottom plate 47 via the lower cap 30. Retained.

  In assembling the assembled battery 1, the unit cell 2 is attached to the bottom plate 47 through the lower cap 30, the external terminals 7 </ b> A and 7 </ b> B of the unit cell 2 are connected by the bus bar 14, and then the unit cell 2 is installed through the upper cap 20. A top plate 41 is attached to the top.

  However, the specific configuration of the holding body 40 is not particularly limited as long as the unit cell 2 can be sandwiched and held via the upper cap 20 and the lower cap 30.

  Hereinafter, specific configurations of the upper cap 20 and the lower cap 30 will be described. In the following description, the longitudinal direction of the battery case 3 in plan view (when viewed from the external terminals 7A and 7B side) is also referred to as “front-rear direction”, and the short direction is also referred to as “left-right direction”. Further, the center side in the longitudinal direction of the battery container 3 is also referred to as “front side”, and the end portion in the longitudinal direction of the battery container 3 is also referred to as “rear side”.

  The configuration of the upper cap 20 and its peripheral portion will be described mainly with reference to FIGS.

  The top wall portion 21 of the upper cap 20 has a rectangular shape. The long side portions 21a and 21b of the top wall portion 21 are arranged to extend in the front-rear direction, and the short side portions 21c and 21d of the top wall portion 21 are arranged to extend in the left-right direction. A rib structure 21 g is provided on the lower surface of the top wall portion 21.

  The outer peripheral surface of the upper convex portion 22 protruding upward from the top wall portion 21 is formed in a tapered shape that gradually tapers toward the upper end. The tip surface 22a of the upper convex portion 22 is generally flat, and a through hole 22b for inspection is provided in the tip surface 22a.

  As shown in FIG. 10, the inspection through hole 22 b is disposed above the external terminals 7 </ b> A and 7 </ b> B covered with the cap 20. The upper convex portion 22 is disposed so as to protrude outside through the through hole 42 of the top plate 41, whereby the inspection through hole 22 b is disposed on the upper side of the top plate 41, that is, outside the holding body 40. . Therefore, without removing the top plate 41 from the assembled battery 1, the tester electrodes and the like can be inserted into the inspection through holes 22b and brought into contact with the external terminals 7A and 7B, thereby removing the top plate 41. In this way, it is possible to inspect the voltage of each single cell 2.

  As shown in FIGS. 8 to 11, the upper cap 20 includes a peripheral wall portion 20a that surrounds the external terminals 7A and 7B from the radially outer side. The peripheral wall portion 20a includes a front wall portion 23 extending downward from the short side portion 21c on the front side of the top wall portion 21, a rear wall portion 24 extending downward from the short side portion 21d on the rear side of the top wall portion 21, and a front wall A pair of side wall portions 25 and 26 that connect the end portions in the left-right direction of the portion 23 and the rear wall portion 24 are provided. The side opposite to the top wall 21 in the axial direction of the peripheral wall 20a is open. The upper cap 20 is attached to the unit cell 2 from the opening side of the peripheral wall portion 20a by being relatively moved along the insertion direction from the upper side to the lower side with respect to the unit cell 2.

  Recessed portions 21e and 21f having an L-shaped cross section are provided at the corner portions between the left and right end portions of the top wall portion 21 and the upper end portions of the side wall portions 25 and 26. The recesses 21e and 21f are formed in a groove shape extending in the front-rear direction from the front end to the rear end of the top wall portion 21.

  The lower end 24a of the rear wall portion 24 and the lower ends 25a, 26a of the side wall portions 25, 26 are arranged at the same height, and at the corner portions of the rear wall portion 24 and the side wall portions 25, 26, these lower ends 24a, 25a, 26a. Are continuous. The lower end 23 a of the front wall portion 23 is disposed above the lower end 24 a of the rear wall portion 24 and the lower ends 25 a and 26 a of the side wall portions 25 and 26.

  As shown in FIG. 9, on the inner side of the upper cap 20, inner connecting portions 27 a and 27 b are provided to straddle the inner surface of the rear wall portion 24 and the inner surfaces of the side wall portions 25 and 26. The lower ends 27c and 27d of the inner connecting portions 27a and 27b are disposed at the same height as the lower end 23a of the front wall portion 23. In a state where the upper cap 20 is attached to the single battery 2, the lower end 23a of the front wall portion 23 abuts on the upper ends of the long side surface portions 3b and 3c of the battery container 3 (see FIG. 7), and the inner connection portions 27a and 27b The lower ends 27c and 27d are in contact with the upper ends of the long side surfaces 3b and 3c and the upper ends of the short side surfaces 3d and 3e of the battery case 3 (see FIGS. 10 and 11).

  The front wall 23 is provided with an inspection opening 23b for arranging a sensor such as a temperature sensor 80 (see FIGS. 11 and 13). The inspection opening 23b is configured by, for example, a notch opened at the lower end 23a of the front wall 23. The inspection terminal portions 10a and 10b of the connecting rods 10A and 10B are sensor mounting portions, and the sensors are fixed to the inspection terminal portions 10a and 10b by screwing or the like.

  The rear wall portion 24 is provided with a bus bar opening 24b through which the bus bar 14 is inserted. The bus bar opening 24b is configured by, for example, a notch opened at the lower end 24a of the rear wall 24. The upper edge of the bus bar opening 24b is disposed above the lower ends 27c and 27d of the inner coupling portions 27a and 27b.

  Protrusions 64 a and 64 b as first pressing portions are provided on the inner surface of the rear wall portion 24. The protrusions 64a and 64b are provided, for example, one each on the right side and the left side of the bus bar opening 24b. Each protrusion 64a, 64b is formed in a rib shape extending in the vertical direction. The lower ends of the protrusions 64a and 64b are connected to the lower end 24a of the rear wall 24, and the upper ends of the protrusions 64a and 64b are connected to the lower ends 27c and 27d of the inner connecting portions 27a and 27b.

  The rear wall portion 24 is an opposing wall portion that faces the short side surface portions 3d and 3e of the battery case 3, and projections 64a and 64b protruding from the inner surface of the rear wall portion 24 are pressed against the short side surface portions 3d and 3e. (See FIG. 11).

  The side wall portions 25 and 26 are provided with bus bar openings 25b and 26b through which the bus bar 14 is inserted. The bus bar openings 25b and 26b are configured by notches opened at the lower ends 25a and 26a of the side walls 25 and 26, for example. The upper edges of the bus bar openings 25b and 26b are arranged above the lower ends 27c and 27d of the inner connecting portions 27a and 27b.

  Protrusions 65a and 65b as third pressing portions are provided on the inner surface of one side wall portion 25, and protrusions 66a and 66b as fourth pressing portions are provided on the inner surface of the other side wall portion 26. In each of the side wall portions 25, 26, one protrusion 65a, 65b, 66a, 66b is provided, for example, one on the front side and the rear side of the bus bar opening portions 25b, 26b.

  Each protrusion 65a, 65b, 66a, 66b is formed in a rib shape extending in the vertical direction. The lower ends of the protrusions 65a, 65b, 66a, 66b are connected to the lower ends of the side wall portions 25, 26. The upper ends of the front projections 65a and 66a are connected to the rib structure 21g on the lower surface of the top wall portion 21, and the upper ends of the rear projections 65b and 66b are connected to the lower ends 27c and 27d of the inner coupling portions 27a and 27b. It is lined up.

  As shown in FIG. 10, the side wall portions 25 and 26 are opposed surface portions that face the long side surface portions 3 b and 3 c of the battery case 3, and the long side surface portions 3 b and 3 c have protrusions protruding from the side wall portions 25 and 26. The parts 65a, 65b, 66a, 66b are pressed. The projecting portions 65a, 65b, 66a, 66b of the side wall portions 25, 26 are formed in a tapered shape in which the protruding height gradually decreases toward the lower end.

  As shown in FIGS. 11 and 13, the inspection terminal portions 10 a and 10 b of the connection rods 10 </ b> A and 10 </ b> B are disposed so as to protrude forward from the front wall portion 23 of the upper cap 20. Therefore, a sensor such as the temperature sensor 80 attached to the inspection terminal portions 10 a and 10 b is disposed so as to protrude forward from the front wall portion 23.

  As shown in FIGS. 8, 9, and 11, in order to protect the sensor attached to the inspection terminal portions 10 a and 10 b, the upper cap 20 is disposed on the opposite side of the front wall portion 23 from the front side, that is, the rear wall portion 24. Further provided are projecting pieces 28 and 29 projecting from each other.

  A pair of projecting pieces 28 and 29 are provided at an interval in the left-right direction. The protruding pieces 28 and 29 are plate-like portions arranged perpendicular to the front wall portion 23, and the front wall portion 23 is a support surface portion that supports the protruding pieces 28 and 29.

  Each of the protruding pieces 28 and 29 includes horizontal portions 28a and 29a extending forward from the front wall portion 23, and vertical portions 28b and 29b extending downward from the front end portions of the horizontal portions 28a and 29a. The lower ends of the horizontal portions 28 a and 29 a are connected to the upper edge of the inspection opening 23 b of the front wall portion 23. The rear ends of the vertical portions 28 b and 29 b are disposed on the front side of the outer surface of the front wall portion 23. At the corner between the lower end and the rear end of the projecting pieces 28, 29, a notch-shaped gap having an L-shaped contour consisting of the lower ends of the horizontal portions 28a, 29a and the rear ends of the vertical portions 28b, 29b 28c and 29c are formed.

  As shown in FIGS. 7 and 13, the pair of projecting pieces 28 and 29 are arranged so as to sandwich the inspection terminal portions 10a and 10b of the connecting rods 10A and 10B from the left and right. In addition, the protruding pieces 28 and 29 are disposed so as to protrude forward from the inspection terminal portions 10a and 10b, and are disposed so as to protrude above the sensors attached to the inspection terminal portions 10a and 10b. Thereby, the pair of projecting pieces 28 and 29 function as a sensor protection unit that protects the sensor projecting forward from the front wall portion 23 of the upper cap 20 from the front, upper, and left and right directions.

  As shown in FIG. 13, the packings 9A and 9B have a pair of engaged portions 9a and 9b disposed adjacent to the inspection terminal portions 10a and 10b in the left-right direction, and these engaged portions 9a. , 9b, the vertical portions 28b, 29b of the protruding pieces 28, 29 are arranged, respectively. As shown in FIG. 11, the lower ends of the vertical portions 28b and 29b of the projecting pieces 28 and 29 are disposed above the lid 5 of the unit cell 2 with a gap therebetween, and the rear corners at the lower ends of the vertical portions 28b and 29b. The portions are engaging portions 28d and 29d as second pressing portions that are engaged from the front side with the engaged portions 9a and 9b of the packings 9A and 9B protruding from the upper surface of the lid 5.

  As shown in FIGS. 12 and 13, when the upper cap 20 configured as described above is attached to the unit cell 2, the peripheral portions of the external terminals 7 </ b> A and 7 </ b> B in the unit cell 2 are sidewall portions of the upper cap 20. The projections 65a, 65b, 66a, 66b of 25, 26 are pressed from both the left and right sides, and the engagement portions 28d, 29d of the projecting pieces 28, 29 of the upper cap 20 and the projections 64a, 64b of the rear wall 24 are used. Pressed from both front and rear. The unit cell 2 is pressed by a plurality of protrusions 64a, 64b, 65a, 65b, 66a, 66b from the right side, the left side, and the rear side, and is also pressed by the plurality of engaging portions 28d, 29d from the front side.

  At this time, the protrusions 65a, 65b, 66a, 66b of the left and right side wall portions 25, 26 are in close contact with the surface of the battery case 3 while being elastically deformed so as to be compressed in the protruding direction. Further, the protrusions 64a and 64b of the rear wall part can be elastically deformed so as to be compressed in the protruding direction, and the protruding pieces 28 and 29 supported by the front wall part 23 are engaged with the packings 9A and 9B. The engaging portions 28d and 29d can be elastically deformed so as to be pushed forward by the portions 9a and 9b. Therefore, regardless of whether or not the battery container 3 of the unit cell 2 is expanded and whether there is a dimensional error between the unit cell 2 and the upper cap 20, the upper cap 20 has the front side, rear side, right side and It is attached in close contact from the left side.

  Since the upper cap 20 is made of a soft polypropylene resin as compared with a polycarbonate resin or the like, the protrusions 64a, 64b, 65a, 65b, 66a, 66b and the protruding pieces 28, 29 are easily elastically deformed.

  As described above, the unit cell 2 is firmly sandwiched by the protrusions 64a, 64b, 65a, 65b, 66a, 66b and the engaging portions 28d, 29d of the upper cap 20 from both sides in the front-rear direction and both sides in the left-right direction. Therefore, the upper cap 20 is prevented from rattling with respect to the unit cell 2 and is reliably positioned with respect to the unit cell 2.

  Therefore, when the top plate 41 is attached to the twelve unit cells 2 attached to the bottom plate 47 via the upper cap 20, the upper convex portions 22 of all the upper caps 20 attached to the unit cells 2 are Since the positioning is accurately performed with respect to the through holes 42 of 41, the upper protrusions 22 can be smoothly inserted into all the through holes 42.

  In addition, since the rattling of the upper cap 20 with respect to the single battery 2 is suppressed, the rattling of the single battery 2 with respect to the top plate 41 is also suppressed, whereby the rigidity of the assembled battery 1 can be improved. .

  Furthermore, since the upper cap 20 has a symmetrical structure, even if the upper cap 20 is attached to any peripheral part of the positive and negative external terminals 7A and 7B in the unit cell 2, a similar attachment state can be obtained. Therefore, the same upper cap 20 can be used to cover either the positive or negative external terminals 7A and 7B.

  Further, the protrusions 65a, 65b, 66a, 66b of the side wall portions 25, 26 of the upper cap 20 have a rib shape extending in the insertion direction of the upper cap 20 (a direction from the upper side to the lower side) and are directed toward the lower end. Accordingly, the protrusion 65a, 65b, 66a, 66b is prevented from being caught on the battery case 3 and the upper cap 20 is smoothly attached to the unit cell 2. be able to.

  In this embodiment, the protrusions 65a, 65b, 66a, 66b of the side walls 25, 26 are formed in a tapered shape over the entire length in the vertical direction, but these protrusions 65a, 65b, 66a, 66b. Only the lower end of the taper may be provided with a taper that gradually decreases in height toward the lower end.

  Further, in the present embodiment, the protrusions 64a and 64b of the rear wall portion 24 are because the engaging portions 28d and 29d of the protruding pieces 28 and 29 are engaged with the engaged portions 9a and 9b of the packings 9A and 9B. First, since it is pressed against the short side surface portions 3d and 3e of the battery case 3, it is difficult to mount the upper cap 20 without providing the taper portions as described above on the projections 64a and 64b of the rear wall portion 24. Is unlikely to occur.

  However, the projecting portions 64a and 64b of the rear wall portion 24 may be formed in a tapered shape over the entire length in the same manner as described above, or a tapered portion may be provided only at the lower end portion.

  Further, as shown in FIGS. 11 and 13, between the engaging portions 28 d and 29 d provided at the lower ends of the protruding pieces 28 and 29 of the upper cap 20 and the front wall portion 23 that supports the protruding pieces 28 and 29. Are provided with the notch-shaped gaps 28c and 29c, and the gaps 28c and 29c are arranged so as to be aligned with the inspection terminal portions 10a and 10b in the left-right direction. Therefore, the gaps 28c and 29c can be used as openings for passing the electric wires 82 extending in the left-right direction from a sensor such as the temperature sensor 80 attached to the inspection terminal portions 10a and 10b.

  Therefore, the wiring of the electric wires 82 connected to the sensors attached to the inspection terminal portions 10a and 10b is not limited to the wiring extending upward or forward from the sensors, but the wiring extending from the sensor in the left-right direction. It is also possible to adopt a rope, and the degree of freedom in routing is improved. Moreover, when arranging the electric wire 82 so that it may extend in the left-right direction, various metal parts such as a safety valve provided on the lid body 5 or the lid body by reducing the portion of the electric wire passing through the lid body 5 The wear of the electric wire 82 due to contact with 5 itself can be suppressed. Furthermore, since the electric wire 82 is led from the sensor to the long side of the lid 5 at the shortest distance, the electric wire 82 can be shortened depending on the way of wiring.

  In addition, since the top wall portion 21 of the upper cap 20 is provided with groove-like depressions 21e and 21f extending in the front-rear direction, a gap is not provided between the top wall portion 21 and the top plate 41. By passing the electric wire 82 through the recessed portions 21e and 21f lower than the upper surface of the top wall portion 21, the electric wire 82 can be guided from the front side to the rear side of the upper cap 20. Thereby, the freedom degree of the wiring of the electric wire 82 further improves.

  Next, the configuration of the lower cap 30 and its peripheral part will be described mainly with reference to FIGS.

  The bottom wall portion 31 of the lower cap 30 has a rectangular shape. The long side part of the bottom wall part 31 is arrange | positioned so that it may extend in the front-back direction, and the short side part of the bottom wall part 31 is arrange | positioned so that it may extend in the left-right direction. A plurality of ribs 91a, 91b, 91c extending in the front-rear direction are provided on the upper surface of the bottom wall portion 31.

  The lower convex portions 32 protruding downward from the bottom wall portion 31 are respectively provided at both longitudinal ends of the bottom wall portion 31. In addition, a protrusion 39 for positioning is provided on the lower surface of the bottom wall portion 31 between the pair of lower convex portions 32. The protrusion 39 is formed in a rib shape extending in the front-rear direction. The protruding portion 39 is disposed so as to be fitted into the opening 43 of the bottom plate 47 only when the lower cap 30 is in a predetermined direction. When the lower cap 30 is in a different direction, the protruding portion 39 is formed on the bottom plate 47. Are supposed to interfere.

  The lower cap 30 includes a pair of long side wall portions 33, 34 extending upward from the long side portion of the bottom wall portion 31, and a pair of short side wall portions 35, 36 extending upward from the short side portion of the bottom wall portion 31. ing. The pair of short side wall portions 35, 36 connect the end portions in the front-rear direction of the pair of long side wall portions 33, 34. The lower cap 30 is attached to the unit cell 2 by being moved relative to the unit cell 2 along the insertion direction from the lower side to the upper side.

  The long side wall portions 33 and 34 are provided with ventilation openings 33a and 34a, respectively. The opening 33a of one long side wall 33 is formed in a cutout shape opened at the upper end of the long side wall 33, and the opening 34a of the other long side wall 34 is formed in a rectangular shape. These openings 33a and 34a are formed to be elongated so as to extend in the front-rear direction.

  Protrusions 93a, 93b, 94a, 94b, 95a, 95b, 96a, 96b are provided on the inner surfaces of the long side walls 33, 34 and the short side walls 35, 36, respectively. In each long side wall part 33 and 34, protrusion part 93a, 93b, 94a, 94b is provided one each before and behind opening part 33a, 34a, for example. In each short side wall 35, 36, a pair of protrusions 95a, 95b, 96a, 96b is provided, for example, with a gap in the left-right direction.

  Each protrusion 93a, 93b, 94a, 94b, 95a, 95b, 96a, 96b is formed in a rib shape extending in the vertical direction. The individual protrusions 93a, 93b, 94a, 94b, 95a, 95b, 96a, and 96b are formed in a tapered shape in which the protruding height gradually decreases toward the upper end. Therefore, when the lower cap 30 is inserted into the unit cell 2 along the direction from the lower side to the upper side, the protrusions 93 a, 93 b, 94 a, 94 b, 95 a, 95 b, 96 a, 96 b with respect to the battery container 3 are reduced. Thus, the lower cap 30 can be smoothly attached to the unit cell 2.

  As shown in FIGS. 16 and 17, when the lower cap 30 configured as described above is attached to the unit cell 2, the lower side of the battery container 3 of the unit cell 2 is connected to the long side wall portion 33 of the lower cap 30. , 34 are pressed from both left and right sides by the projections 93a, 93b, 94a, 94b, and are pressed from both the front and rear sides by the projections 95a, 95b, 96a, 96b of the short side walls 35, 36 of the lower cap 30. Further, the battery case 3 is pressed by a plurality of protrusions 93a, 93b, 94a, 94b, 95a, 95b, 96a, 96b from the right side, the left side, the front side, and the rear side, respectively.

  At this time, the individual protrusions 93a, 93b, 94a, 94b, 95a, 95b, 96a, 96b are elastically deformable, and all the protrusions 93a, 93b, 94a, 94b, 95a, 95b, 96a, 96b are batteries. Adheres closely to the surface of the container 3. Therefore, regardless of whether the battery container 3 of the unit cell 2 is expanded and whether there is a dimensional error between the unit cell 2 and the lower cap 30, the lower cap 30 has the front side, rear side, right side and It is attached in close contact from the left side.

  As described above, the lower cap 30 is also reliably positioned with respect to the unit cell 2, as the upper cap 20 is prevented from rattling. Therefore, the unit cell 2 held by the top plate 41 and the bottom plate 47 via the upper cap 20 and the lower cap 30 is improved in positioning accuracy with respect to the holding body 40 having the top plate 41 and the bottom plate 47, and also to the holding body 40. The rattling is suppressed, whereby the rigidity of the assembled battery 1 can be further improved.

  While the present invention has been described with reference to the above-described embodiments, the present invention is not limited to the above-described embodiments.

  For example, in the above-described embodiment, an example in which the upper cap 20 is provided for each external terminal and the lower cap 30 is provided for each power storage element has been described. Instead, a plurality of covering portions that cover individual external terminals are provided. And / or a lower cap formed by integrating a plurality of covering portions covering the bottom side of each power storage element may be used. As for the upper cap 20, for example, as shown in FIG. 10, the upper caps 20 and 20 adjacent to each other in the short direction of the terminal surface portion are integrated with each other at the side wall portions 25 and 26, or as shown in FIG. It is conceivable to form one upper cap having a plurality of covering portions 20, 20 by integrating the upper caps 20, 20 adjacent to each other in the longitudinal direction of the surface portions at the rear wall portions 24, 24. .

  Moreover, although the above-mentioned embodiment demonstrated the example in which the convex to-be-engaged parts 9a and 9b are provided in a terminal surface part, in this invention, the to-be-engaged part provided in a terminal surface part has a 2nd pressing part. As long as it can be pressed, it is not limited to a convex shape.

  Furthermore, in the above-described embodiment, a pair of protrusions are provided on the rear wall portion 24 and the side wall portions 25 and 26 of the upper cap 20 and the long side wall portions 33 and 34 and the short side wall portions 35 and 36 of the lower cap 30. In the present invention, the number of protrusions provided on each surface is not limited.

  Moreover, although the above-mentioned embodiment demonstrated the example in which each protrusion part was formed in rib shape, in this invention, the shape of a protrusion part is not specifically limited.

  Furthermore, in the above-described embodiment, protrusions are provided on the side wall portions 25 and 26 on both sides of the upper cap 20, and protrusion portions are provided on the long side wall portions 33 and 34 on both sides of the lower cap 30, and both sides of the lower cap 30 are provided. In the present invention, one of the side wall portions 25 and 26 of the upper cap 20, one of the long side wall portions 33 and 34 of the lower cap 30, or A protrusion may be provided on only one of the short side wall portions 35 and 36 of the lower cap 30.

  In the above-described embodiment, the configuration in which each protrusion is elastically deformable has been described. However, in the present invention, a plastically deformable protrusion may be provided instead of the elastically deformable protrusion. Even when the protrusion is plastically deformed, a part of the protrusion is elastically deformed, so that the urging force of the protrusion can act on the power storage element.

  Furthermore, in the above-described embodiment, the power storage device according to the present invention has been described by taking as an example a power storage device having a non-aqueous electrolyte secondary battery such as a lithium ion secondary battery as a power storage element. The power storage elements to be configured may be various power storage elements including secondary batteries other than non-aqueous electrolyte secondary batteries, primary batteries, and capacitors.

  In addition, the present invention is not limited to an assembled battery having a plurality of power storage elements, and can also be applied to a power storage device including only one power storage element.

1 battery pack (power storage device)
2 Single battery (storage element)
3 Battery container 3a Bottom surface portion 3b, 3c Long side surface portion 3d, 3e Short side surface portion 5 Lid (terminal surface portion)
7A, 7B External terminal 9A, 9B Packing 9a, 9b Engagement part 10A, 10B Connection rod 10a, 10b Inspection terminal part 14 Bus bar 20 Upper cap 21 Top wall part 21e, 21f Depression part 22 Upper convex part 23 Front wall part 24 Rear wall (opposite wall)
25, 26 Side wall part 27a, 27b Inner coupling part 28, 29 Projection piece (sensor protection part)
28a, 29a Horizontal portion 28b, 29b Vertical portion 28c, 29c Opening 28d, 29d Engagement portion (second pressing portion)
30 Lower cap 31 Bottom wall portion 32 Lower convex portion 33, 34 Long side wall portion 35, 36 Short side wall portion 40 Holder 41 Top plate 42 Through hole 45, 46 Side plate 47 Bottom plate 48 Through hole 60 Monitoring device 64a, 64b Projection portion ( First pressing part)
65a, 65b Projection part (third pressing part)
66a, 66b Projection part (fourth pressing part)
70 Heat shield 73, 74 Projection part 78 Guide member 80 Temperature sensor 82 Electric wire 93a, 93b, 94a, 94b, 95a, 95b, 96a, 96b Projection part

Claims (7)

A storage element having a rectangular terminal surface portion, an external terminal provided on the terminal surface portion, and a short side surface portion continuous with a short side of the terminal surface portion;
A cap that covers the external terminal;
An engaged portion is provided on the terminal surface portion,
The cap includes a first pressing portion that is pressed against the short side surface portion from one side in the longitudinal direction of the terminal surface portion, and a second pressing portion that is pressed against the engaged portion from the other side in the longitudinal direction of the terminal surface portion. have a,
The cap has a peripheral wall portion surrounding the external terminal,
The peripheral wall portion of the cap has an opposing wall portion facing the short side surface portion,
The first pressing part is a protrusion provided on the inner surface of the opposing wall part,
One side in the axial direction of the peripheral wall portion of the cap is open,
The protruding portion is a power storage device formed in a rib shape extending in the axial direction . The cap has a protruding piece which protrudes outward from the front Symbol peripheral wall,
The power storage device according to claim 1, wherein the second pressing portion is provided at a tip portion of the protruding piece. A sensor mounting portion for mounting a sensor is provided on the terminal surface portion,
A gap is formed between the peripheral wall portion and the second pressing portion in the cap,
The power storage device according to claim 2, wherein the gap is an opening for passing an electric wire extending from the sensor.   The power storage device according to claim 3, wherein the sensor attachment portion and the opening are arranged side by side in a short direction of the terminal surface portion. 5. The power storage device according to claim 1 , wherein the protrusion has a tapered shape in which a protrusion height gradually decreases toward the one side in the axial direction. The power storage element includes a first long side surface portion continuous with one long side of the terminal surface portion, and a second long side surface portion continuous with the other long side of the terminal surface portion,
The cap is pressed against the first long side surface portion from the one side in the short direction of the terminal surface portion and the second long side surface portion from the other side in the short direction of the terminal surface portion. The power storage device according to any one of claims 1 to 5 , further comprising a fourth pressing portion. The power storage device according to any one of claims 1 to 6 , further comprising a holding body that holds the power storage element via the cap.

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