JP2014143124A - Power storage device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To surely prevent a support wall of a power storage cell case from being deflected when power storage cell cases each accommodating a power storage cell are stacked two highs or more in the vertical direction.SOLUTION: A power storage device 11 is configured by stacking power storage cell cases 12 for accommodating a plurality of storage cells 19 in the vertical direction while being arranged in a plurality of stages, a space α is created on top of which between the underside of a support wall 12f of the power storage cell case 12 for supporting the power storage cells 19 and the power storage cells 19 supported by the power storage cell case 12 located downward thereof. This gives rise to a possibility that, when the support wall 12f is deflected downward by a weight of the power storage cells 19, a gap is generated between the top face of the support wall 12f and the underside of the power storage cells 19, it becomes difficult for heat of the power storage cells 19 to be released into the power storage cell case 12. However, because a reinforcement part 12h protruding to the interior of the gap α is provided on the underside of the support wall 12f, the reinforcement part 12h not only can reinforce the support wall 12f to prevent its deflection, but also can increase the surface area of the support wall 12f to heighten its heat radiation performance.

Description

  The present invention provides a storage cell case for storing a plurality of storage cells stacked in a plurality of stages in the vertical direction, and the storage cell positioned on the lower surface of a support wall of the storage cell case for supporting the storage cell on the upper surface. The present invention relates to a power storage device in which a space is formed between the power storage cells supported by a case.

  When stacking power storage modules containing a plurality of power storage cells inside a metal outer case in multiple stages in the vertical direction, the flanges of the outer case of the upper and lower power storage modules are connected via a plurality of spacers. Patent Document 1 below discloses that the upper power storage module prevents the weight of the upper power storage module from being directly applied to the upper wall of the outer case of the lower power storage module.

JP 2009-026601 A

  By the way, the above conventional one has a space between the lower wall of the outer case of the upper power storage module and the upper wall of the outer case of the lower power storage module. May be bent downward by the weight of the storage cell. In particular, when a cooling structure that dissipates heat by transferring the heat generated by the storage cell to the lower wall of the outer case, if the lower wall of the outer case bends, the storage cell and the outer case will not be in close contact with each other. There is a problem that the cooling effect is not fully exhibited.

  The present invention has been made in view of the above circumstances, and when the storage cell cases for storing the storage cells are stacked in a plurality of stages in the vertical direction, the support wall of the storage cell case is reliably prevented from being bent with a simple structure. The purpose is to do.

  In order to achieve the above object, according to the first aspect of the present invention, the storage cell case for storing a plurality of storage cells is stacked in a plurality of stages in the vertical direction, and the storage cell supports the storage cell on the upper surface. A power storage device in which a space is formed between a lower surface of a support wall of a case and the power storage cell supported by the power storage cell case located below the case, and protrudes into the space on a lower surface of the support wall A power storage device having a reinforcing portion is proposed.

  According to the invention described in claim 2, in addition to the configuration of claim 1, a power storage device is proposed in which the reinforcing portion is disposed along the longitudinal direction of the lower surface of the support wall. .

  According to a third aspect of the present invention, in addition to the configuration of the first or second aspect, the reinforcing portion is formed in a hollow closed cross section, and the refrigerant flows through the inside thereof. Is proposed.

  According to the invention described in claim 4, in addition to the configuration of claim 3, a power storage device is proposed in which a heat pipe is embedded in the reinforcing portion.

  According to a fifth aspect of the present invention, in addition to the configuration of the fourth aspect, a power storage device characterized in that a linear expansion coefficient of the heat pipe substantially matches a linear expansion coefficient of the power storage cell case. Proposed.

  The reinforcing rib 12h in the embodiment corresponds to the reinforcing portion of the present invention.

  According to the configuration of claim 1, the power storage device is configured by stacking power storage cell cases that store a plurality of power storage cells in a plurality of stages in the vertical direction, and the support wall of the power storage cell case that supports the power storage cells on the upper surface. Since a space is formed between the lower surface and the energy storage cell supported by the energy storage cell case located below the upper surface of the energy storage cell and the lower surface of the energy storage cell when the support wall bends downward due to the weight of the energy storage cell. There is a possibility that a gap will be generated between them and it will be difficult for the heat of the storage cell to escape to the storage cell case, but since the reinforcement part protruding into the space is provided on the lower surface of the support wall, it is supported by the reinforcement part Not only can the wall be reinforced to prevent the occurrence of bending, but the surface area of the support wall can be increased at the reinforced portion to improve heat dissipation.

  According to the configuration of the second aspect, since the reinforcing portion is arranged along the longitudinal direction of the lower surface of the support wall, the reinforcing wall is attached to the supporting wall of the storage cell case in which the central portion in the longitudinal direction is easily bent downward by the weight of the storage cell. Thus, the support wall can be effectively reinforced, and the bending of the support wall can be more reliably prevented.

  According to the third aspect of the present invention, the reinforcing portion is formed in a hollow closed cross section, and the refrigerant flows through the inside. Therefore, the heat generated by the storage cell is transferred from the support wall of the storage cell case to the refrigerant flowing inside the reinforcing portion. By dissipating heat, the storage cell can be efficiently cooled.

  According to the fourth aspect of the present invention, since the heat pipe is embedded in the reinforcing portion, the storage cell can be further efficiently cooled by the heat pipe.

  According to the fifth aspect of the present invention, since the linear expansion coefficient of the heat pipe substantially matches the linear expansion coefficient of the storage cell case, it is possible to prevent a dimensional difference between the heat pipe and the storage cell case due to temperature change. Durability can be increased.

The perspective view of an electrical storage apparatus. (First embodiment) The perspective view of an electrical storage cell case and an electrical storage module. (First embodiment) 3 (A) direction and 3 (B) direction arrow view of FIG. (First embodiment) FIG. 4 is a cross-sectional view taken along line 4-4 of FIG. (First embodiment) The partial exploded perspective view of an electrical storage apparatus. (Second Embodiment) FIG. 6 is a view in the direction of arrows 6 in FIG. (Second Embodiment)

First embodiment

  Hereinafter, a first embodiment of the present invention will be described with reference to FIGS.

  As shown in FIGS. 1 and 2, the power storage device 11 of the electric vehicle includes three storage cell cases 12, one upper cover 13, and one lower cover 14. Three power storage cell cases 12 are stacked on the upper surface of 14, and the upper cover 13 is coupled to the upper surface of the uppermost power storage cell case 12.

  The lower cover 14 made of a light metal such as aluminum is a tray-like member having an open upper surface, and a plurality of boss portions 14c are projected along flanges 14b surrounding the upper edges of the side walls 14a. The three storage cell cases 12 made of a light metal such as aluminum are the same interchangeable members, and a plurality of bosses are provided along the flanges 12b ..., 12c ... surrounding the lower and upper edges of the side walls 12a ... The parts 12d ..., 12e ... are projected. The upper cover 13 made of a light metal such as aluminum is a tray-like member having an open lower surface, and a plurality of boss portions 13c are projected along flanges 13b surrounding the lower edge of the side wall 13a.

  The upper edge flange 14b of the lower cover 14 and the lower edge flange 12b of the lower storage cell case 12 are brought into contact with each other, and the bosses 14c, 12d of the two are fastened with bolts 15 ... The lower storage cell case 12 is coupled to the upper portion of the cover 14. The upper flange 12c of the lower storage cell case 12 and the lower flange 12b of the middle storage cell case 12 are brought into contact with each other, and the bosses 12e, 12d,. Thus, the middle storage cell case 12 is coupled to the upper part of the lower storage cell case 12. Similarly, the upper storage cell case 12 is coupled to the upper part of the middle storage cell case 12. The upper edge flange 12c of the upper storage cell case 12 and the lower edge flange 13b of the upper cover 13 are brought into contact with each other, and the bosses 12e, 13c,. An upper cover 13 is coupled to the upper part of the storage cell case 12.

  As shown in FIGS. 2 to 4, rectangular support walls 12 f are formed so as to connect intermediate portions in the height direction of the side walls 12 a of each storage cell case 12, and six pieces are provided on the upper surface of the support walls 12 f. Are stored. Each power storage module 18 includes power storage cells 19 made of twelve stacked lithium ion batteries (see FIG. 2), and a pair of end plates 20, 20 are further provided on both sides of the power storage cells 19, 19 at both ends. In the stacked state, the two storage cells 19 are integrated by fastening both ends of the pair of restraining bands 21 and 21 to the end plates 20 and 20 with bolts 44. A cover 22 is attached to the upper surface of the power storage module 18.

  Two brackets 20a, 20a project from the outer surface of each end plate 20, and these brackets 20a, 20a are bolts 23 on mounting seats 12g provided at the connecting portions of the support wall 12f and the side walls 12a, 12a. The six power storage modules 18 are fixed to the power storage cell case 12 by fastening at. In this state, the flat lower surface of each of the energy storage cells 19 of the energy storage module 18 is in close contact with the flat upper surface of the support wall 12f of the energy storage cell case 12. Further, a space α is formed between the upper surface of the storage cells 19 and the lower surface of the support wall 12f facing the upper side (see FIG. 4).

  On the lower surface of the support wall 12f of the storage cell case 12, one reinforcing rib 12h that is bent in a substantially S-shape is projected. The reinforcing rib 12h connects the three straight portions a, b, and c extending in parallel with each other along the longitudinal direction of the support wall 12f and connects the end portions of the straight portions a, b, and c in a U shape. Two bent portions d and e and a connecting portion f extending from the end of the straight portion c along the short direction of the support wall 12f. A heat pipe 24 is inserted into the inside of the reinforcing rib 12h having a hollow closed cross section at the time of casting. The reinforcing ribs 12h are arranged to face the lower surfaces of the six power storage modules 18 with a substantially equal length.

  In addition, two drain holes 12k and 12k for discharging the water accumulated there are formed at diagonal positions of the support wall 12f (see FIGS. 3 and 4).

  The well-known heat pipe 24 is a pipe material made of light metal such as aluminum, which is the same material as the storage cell case 12, in which a volatile working fluid as a refrigerant is sealed, and its inner wall surface has a capillary structure. Covered with wick. The two ends of the heat pipe 24 are drawn out of the side wall 12a from the end of the straight portion a and the end of the connecting portion f of the reinforcing rib 12h, and two heat exchanges arranged in the vertical direction outside the power storage device 11 Connected to devices 25 and 25.

  Note that only two power storage cells 19 and 19 are supported on the support wall 14d (see FIG. 1) of the lower cover 14, and formed inside the lower cover 14 by reducing the number of power storage cells 19 and 19. In this space, the charge / discharge control devices for the power storage cells 19, the motor / generator control device fed from the power storage device 11, and the like are stored. On the lower surface of the support wall 14 d of the lower cover 14, similarly to the lower surface of the support wall 12 f of the storage cell case 12, a reinforcing rib (not shown) with a heat pipe 24 inserted is provided.

  Next, the operation of the first embodiment of the present invention having the above configuration will be described.

  When the storage cells 19 generate heat by charging and discharging, the heat is transmitted from the lower surface of the storage cells 19 to the support walls 12f of the storage cell cases 12 and is radiated from the support walls 12f to the heat pipe 24. At this time, in order to efficiently transfer heat from the storage cells 19 to the support wall 12f, the lower surface of the storage cells 19 needs to be in close contact with the upper surface of the support wall 12f of the storage cell cases 12 ... When the support wall 12f is bent downward toward the space α by the weight of the storage cells 19 ..., a gap is generated between the lower surface of the storage cells 19 ... and the upper surface of the support wall 12f of the storage cell cases 12 ... Transmission may be hindered.

  However, according to the present embodiment, the reinforcing rib 12h is protruded from the lower surface of the support wall 12f. Therefore, the reinforcing rib 12h increases the rigidity of the support wall 12f to prevent the occurrence of bending, and the storage cells 19. The lower surface can be brought into close contact with the upper surface of the support wall 12f of the storage cell cases 12. Moreover, the required rigidity can be ensured while minimizing the increase in weight as compared with the case where the thickness of the support wall 12f is increased as a whole. Further, since the surface area of the support wall 12f is increased by forming the reinforcing rib 12h, heat radiation from the support wall 12f to the space α can be promoted.

  The heat transferred from the storage cells 19 to the support wall 12f is transferred to the heat pipe 24 inserted into the reinforcing rib 12h. When the heat pipe 24 is heated, the refrigerant enclosed therein is vaporized and flows into the heat exchangers 25 and 25 which are low-temperature parts, where it is liquefied by exchanging heat with the low-temperature outside air. The liquefied refrigerant is absorbed by the wick on the inner peripheral surface of the heat pipe 24, is transmitted through the wick by a capillary phenomenon, and is returned again to the support wall 12f side, which is a high temperature portion, to repeatedly cool the support wall 12f.

  Further, since the straight portions a, b, and c of the reinforcing rib 12h are arranged along the longitudinal direction of the lower surface of the support wall 12f of the storage cell case 12, the longitudinal center portion is easily bent downward by the weight of the storage cells 19. The wall 12f can be effectively reinforced by the reinforcing rib 12h, and the bending of the support wall 12f can be more reliably prevented. In addition, since the storage cell case 12 and the heat pipe 24 are made of the same material aluminum alloy, the linear expansion coefficients of the storage cell case 12 and the heat pipe 24 are matched. It is possible to prevent the occurrence of a dimensional difference between them, and to prevent the contact portion between the two from peeling and lowering the durability.

Second embodiment

  Next, a second embodiment of the present invention will be described based on FIG. 5 and FIG.

  The power storage device 11 of the second embodiment includes three power storage cell cases 12 that are stacked in the vertical direction and one upper cover 13 that is coupled to the upper surface of the upper power storage cell case 12. The storage cell case 12 of the first embodiment is provided with a support wall 12f at an intermediate portion in the vertical direction, whereas the storage cell case 12 of the second embodiment is provided with a support wall 12f at the lower end, and the support thereof. Four power storage modules 18 are supported on the wall 12f. The three storage cell cases 12... And the upper cover 13 are stacked in the vertical direction and joined by bolts 16, 17, etc., as in the first embodiment.

  A bulging portion 12i projects from a side wall 12a on one end in the longitudinal direction of the storage cell case 12, and a rectangular opening 12j formed in the bulging portion 12i is closed by a detachable lid 27 with bolts 26 ... Is done. Two total terminals 28 and 29 are provided on the side wall 12a inside the opening 12j of the bulging portion 12i. The total terminals 28 and 29 are terminals to which both ends of the four power storage modules 18... Electrically connected in series inside the power storage cell case 12 are connected.

  The bus bar plate 30 inserted into the bulging portion 12i is fixed to the main body 31 having a rectangular plate-like main body 31, a cover 33 coupled with bolts 32 to cover the surface of the main body 31. Three first to third bus bars 34, 35, and 36 are provided. Two terminals 37, 38 are provided at both ends of the first bus bar 34, two terminals 39, 40 are provided at both ends of the second bus bar 35, and two terminals are provided at both ends of the third bus bar 36. 41 and 42 are provided. Six bolt insertion holes 33a... Facing the six terminals 37 to 42 are formed in the cover member 33, and a gripping portion 33b is provided at the upper end of the cover member 33.

  In addition, the point which forms the reinforcement rib 12h which equipped the heat pipe 24 in the lower surface of the support wall 12f of the electrical storage cell case 12 is the same as that of 1st Embodiment.

  Next, the operation of the second embodiment of the present invention having the above configuration will be described.

  In order to connect between the total terminals 28 and 29 provided in the three storage cell cases 12 of the storage device 11, first, the upper cover 13 is removed from the upper surface of the upper storage cell case 12, and the storage cell case With the 12 lids 27 removed, the lids are inserted into the bulging portions 12i of the three storage cell cases 12 laminated with the bus bar plates 30 that are held and suspended by the gripping portion 33b. In this state, the six terminals 37 to 42 of the first to third bus bars 34, 35, and 36 of the bus bar plate 30 face the three pairs of total terminals 39 to 40 of the three storage cell cases 12. .

  Subsequently, the six bolts 43 inserted from the openings 12j of the three storage cell cases 12 are connected to the bolt insertion holes 33a of the bus bar plate 30 and the terminals 37 of the first to third bus bars 34, 35, 36. ˜42 are penetrated and fastened to the three pairs of total terminals 39..., 40. As a result, the total terminals 28... 29 of the three storage cell cases 12 are electrically connected in series via the first to third bus bars 34, 35, 36, and the total storage cell case 12 in the lower stage is connected. It is possible to output from the terminals 28 and 29. And finally, the assembly of the electrical storage apparatus 11 is completed by attaching the upper cover 13 and the three lids 27.

  When the maintenance of the connection state of the bus bar plate 30 is performed, the lids 27 can be removed to expose the openings 12j of the bulged portions 12i, so that the maintenance can be performed through the openings 12j.

  The embodiments of the present invention have been described above, but various design changes can be made without departing from the scope of the present invention.

  For example, the storage cell 19 of the embodiment is not limited to a lithium ion battery, and may be another type of battery or capacitor.

  Further, the reinforcing portion of the present invention is not limited to the reinforcing rib 12h of the embodiment, and includes a portion in which no refrigerant flows through the inside.

  Moreover, the refrigerant | coolant which distribute | circulates the inside of the reinforcement rib 12h is not limited to the refrigerant | coolant enclosed with the heat pipe 24 of embodiment, Cooling air and cooling water may be sufficient.

  The material of the heat pipe 24 is not limited to aluminum in the embodiment, and may be brass or the like.

12 Storage cell case 12f Support wall 12h Reinforcement rib (reinforcement part)
19 Storage cell 24 Heat pipe α space

Claims (5)

A storage cell case (12) for storing a plurality of storage cells (19) is stacked in a plurality of stages in the vertical direction, and a support wall (12f) of the storage cell case (12) for supporting the storage cell (19) on an upper surface thereof. A power storage device in which a space (α) is formed between a lower surface and the power storage cell (19) supported by the power storage cell case (12) positioned below the lower surface,
A power storage device comprising a reinforcing portion (12h) protruding into the space (α) on a lower surface of the support wall (12f).   The power storage device according to claim 1, wherein the reinforcing portion (12h) is arranged along a longitudinal direction of a lower surface of the support wall (12f).   The power storage device according to claim 1 or 2, wherein the reinforcing portion (12h) is formed in a hollow closed cross section, and a refrigerant flows through the inside.   The power storage device according to claim 3, wherein a heat pipe (24) is embedded in the reinforcing portion.   The power storage device according to claim 4, wherein a linear expansion coefficient of the heat pipe (24) substantially matches a linear expansion coefficient of the power storage cell case (12).

Images