JP5229303B2 - Battery pack for vehicles - Google Patents

Description

  The present invention relates to a vehicle battery pack including a plurality of prismatic battery cells stacked in the thickness direction, and particularly to a technique for suitably suppressing expansion of any of the prismatic battery cells.

  As a type of relatively large-capacity power supply device used for electric vehicles, hybrid vehicles, and the like, a vehicle battery pack is known that includes an assembled battery in which a plurality of flat rectangular battery cells are stacked in the thickness direction. ing. Since the vehicle battery pack provided with such an assembled battery is configured to be compact and lightweight, there is an advantage that it can be mounted in a limited space in an automobile. The prismatic battery cell is a thin hollow rectangular parallelepiped box made of synthetic resin, and a plurality of battery cases for accommodating the electrolyte and electrode bodies constituting the secondary battery are arranged therein. ing.

  Since such a square battery cell having a plurality of battery cases is made of synthetic resin, for example, when the internal pressure of the battery case rises above a predetermined value due to generation of hydrogen gas or the like in the battery case, However, if the internal pressure further increases for some reason, the synthetic resin prismatic battery cell may expand particularly in the thickness direction. Further, in this rectangular battery cell, the internal pressure rises and expands in the thickness direction even at the time of overdischarge reaction, at the time of overcharge reaction, at the time of lowering the gas absorption performance at low temperature, and the like.

  For this reason, in Patent Document 1, an assembled battery in which a plurality of rectangular battery cells are stacked in the thickness direction is sandwiched between a pair of end plates, and the pair of end plates are placed outside the assembled battery. The structure which mutually couple | bonds by each pair of restraint band arrange | positioned along the lamination direction of a square battery cell is disclosed.

JP-A-9-120809

  By the way, according to the conventional configuration as described above, each rectangular battery cell is pressed by being sandwiched between a pair of end plates, and therefore the expansion of each rectangular battery cell can be suppressed to some extent. . However, when a large number of prismatic battery cells are arranged between a pair of end plates, when a predetermined prismatic battery cell expands, the pressure due to the expansion is dispersed by the compression elastic deformation of the other prismatic battery cells. Therefore, there is a possibility that the expansion of the predetermined prismatic battery cell cannot be suppressed.

  The present invention has been made against the background of the above circumstances, and the object of the present invention is to reliably prevent the expansion of prismatic battery cells arranged in a stacked state in the thickness direction, and to vibrate. The present invention is to provide a vehicle battery pack in which the prismatic battery in the assembled battery is not likely to shift.

  The gist of the vehicle battery pack of the present invention for achieving the above object is a vehicle battery pack including an assembled battery in which a plurality of flat plate-shaped square battery cells are stacked in the thickness direction. In addition, the assembled battery is provided with a pair of restraint plates that are respectively abutted against the prismatic battery cells located at both ends in the stacking direction, so that the prismatic battery cells between the restraint plates are pressed. The pair of restraining plates are connected to each other by long connecting members arranged on both sides of the square battery cell, and the assembled battery is accommodated in the assembled battery case. Comprises a lower case and an upper case provided with flange portions projecting in the width direction of the prismatic battery cell on both sides, respectively, and the lower flange portion of the lower case and the upper flange portion of the upper case are compatible with each other. To be fixed integrally coupled, lies in the lower flange portion of said lower case in a state where gaps are formed between the lower case and the vehicle body is fixed to the vehicle body.

  According to the above-described vehicle battery pack of the present invention, the rectangular battery cells arranged on both sides of the prismatic battery cell so that the prismatic battery cell between the pair of restraining plates is pressed, that is, the preload is generated. Since the pair of restraint plates are connected to each other by the connecting member, a plurality of prismatic battery cells sandwiched between the pair of restraint plates are pressed in the thickness direction, so that each square battery cell expands. Is preferably prevented. Moreover, the shift | offset | difference etc. of the adjacent square battery cell are prevented reliably.

  Here, it is preferable that a positioning protrusion and a positioning recess for positioning with respect to other rectangular battery cells adjacent to each other in the thickness direction are provided on the mutually facing surfaces of the respective square battery cells. The positioning protrusion and the positioning recess are fitted to the positioning recess and the positioning protrusion provided in the adjacent prismatic battery. In this way, a shift in the direction orthogonal to the thickness direction of each rectangular battery cell is suitably prevented.

  Preferably, the connecting members are arranged on the upper side and the lower side of the prismatic battery cell, respectively, and the tightening allowance to the pair of restraining plates by the connecting member located on the upper side is lower side. This is larger than the tightening allowance for the pair of restraining plates by the connecting member located at the position. In this way, in the assembled battery, pressure is also reliably applied to the upper side of the prismatic battery cell located in the central portion of the prismatic battery cell in the stacking direction, so that any one of the prismatic battery cells extends in the thickness direction. When expanded, the prismatic battery cell located at the center thereof is preferably prevented from lifting upward.

  Preferably, the connecting member is disposed on an upper side and a lower side of the prismatic battery cell, and each of the prismatic battery cells has an upper part thicker than a lower part. Is. In this way, when each square battery cell is pressed in the thickness direction by being sandwiched between a pair of restraining plates coupled to the coupling member, the upper part of the prismatic battery cell is sandwiched more strongly than the lower part. When any one of the square battery cells expands in the thickness direction, the square battery cell located at the center in the stacking direction is preferably prevented from lifting upward.

  Preferably, the pair of constraining plates have a shape in which a central portion in the width direction bulges to the side opposite to the prismatic battery cell side. In this way, when each rectangular battery cell is pressed in the thickness direction by being sandwiched between a pair of restraining plates connected by the connecting member, the end in the width direction of the rectangular battery cell is the central part. Therefore, the prismatic battery cell is preferably prevented from shifting in the width direction.

  Preferably, the lower case includes a bottom surface portion, a pair of side surface portions extending from both side edges of the bottom surface portion to the upper case side, and a pair of side surface portions extending outward from the pair of side surface portions. The lower flange portion to be taken out, and a lower space for circulating cooling gas is formed between the bottom surface portion and the lower end surface of the rectangular battery cell, and the upper case is An upper surface portion smaller than the width of the prismatic battery cell, a pair of upper side surfaces pressing the upper end surface of the prismatic battery cell from both end edges of the upper surface portion toward the prismatic battery cell, and the pair of upper side surfaces A pair of stepped portions extending in directions away from the tips of the respective parts, a pair of side surface portions extending from the tips of the pair of stepped portions to the lower case side, and a tip of the pair of side surface portions The upper flanges extending outward And an upper space communicated with the lower space through a gap between the square battery cells is provided between the upper surface portion and the upper end surface of the square battery cell. . In this way, since the assembled battery made up of the stacked rectangular battery cells is housed in the assembled battery case made up of the lower case and the upper case, the lower space and the upper space in the assembled battery case. Therefore, each square battery cell can be efficiently cooled as a whole. Incidentally, in the battery pack, when the assembled battery is accommodated in the assembled battery case, a sufficient space cannot be formed in the assembled battery case. There was also a possibility that it could not be cooled efficiently.

  Preferably, a space for circulating a cooling gas is provided between the lower case and the lower end surface of the prismatic battery cell and between the upper case and the upper end surface of the prismatic battery cell. Each is provided. If it does in this way, each square type battery can be cooled efficiently and reliably by using effectively the space in an assembled battery case as a passage of cooling air.

  Preferably, an elastic member that can be elastically deformed is interposed between the upper case and the upper surface of any one of the rectangular battery cells constrained between the pair of constraining plates. In this way, the upper surface of the prismatic battery cell is held by the upper case via the elastic member, so that the assembled battery housed in the assembled battery case is preferably prevented from rattling. Incidentally, when the assembled battery and the assembled battery case are not securely fixed, the assembled battery vibrates due to the vibration of the automobile when it is loaded on a hybrid vehicle or the like, and any of the square battery cells is displaced. There is also a fear. In an assembled battery, if any one of the prismatic battery cells is displaced, a load is applied to the plurality of prismatic battery cells constituting the assembled battery in the thickness direction to suppress expansion of each of the prismatic battery cells. There was a risk that it would be impossible.

  Preferably, the elastic member is composed of a longitudinal cylindrical hollow body made of synthetic rubber or synthetic resin, for example. In this way, the movement of the assembled battery can be reliably absorbed without applying a large load to the assembled battery from the upper case, and a lightweight and low-rigidity upper case made of a thin metal plate is used. Can do.

  Preferably, an intermediate constraining plate is interposed between the prismatic battery cells stacked in the thickness direction in the assembled battery, and the intermediate constraining plate is connected to the upper side and the lower side of the prismatic battery cell. It is positioned by the member. In this way, since the intermediate restraint plate is disposed at an appropriate location between the plurality of stacked square battery cells and the intermediate restraint plate is fixed to the connecting member, each square battery cell is expanded. Even more reliably deterred.

  Preferably, at least one pair of prismatic battery cells of the plurality of prismatic battery cells stacked in the thickness direction is provided with engagement protrusions on each side surface, and the engagement protrusions. A longitudinal expansion restraining plate that is provided with an engagement hole portion that engages with each of the rectangular battery cells so as not to move in the stacking direction of the respective square battery cells is provided. In this way, when any one of the square battery cells is expanded, the expansion restraining plate prevents the at least one pair of the square battery cells from being separated, so that the battery is positioned between the pair of square battery cells. Expansion of the rectangular battery cell is suitably suppressed.

  Preferably, the engagement protrusions projecting from both side surfaces of the rectangular battery cell have a disengagement prevention device for maintaining the engagement state with the engagement hole of the expansion suppression plate. Is provided. If it does in this way, engagement with the engagement protrusion part of a square battery cell and the engagement hole part of an expansion | swelling suppression board is ensured by the disengagement prevention apparatus.

  Preferably, at least one of the constraining plates has a pressing device that applies a preload to the rectangular battery cells in order to elastically press the plurality of rectangular battery cells stacked in the thickness direction. Is provided. In this way, since the preload is applied by the pressing device, even if the restraint plate is displaced, the plurality of rectangular battery cells are appropriately pressed.

  Preferably, any of the plurality of prismatic battery cells is fixed to a lower case or an upper case of the assembled battery case by a fixing device. In this way, since the rectangular battery cell is fixed to the lower case or the upper case, the expansion of the rectangular battery cell is more preferably suppressed.

  Preferably, a positioning member for determining a stacking position in the thickness direction is provided at a predetermined position of each square battery cell, and the square battery cells adjacent to each other between the pair of restraining plates are provided. The positioning members attached to each other are pressed against each other. In this way, since the rectangular battery cell is restrained in the thickness direction by the positioning member, expansion due to an increase in the internal pressure of the predetermined rectangular battery cell is suppressed. Further, it is possible to prevent an excessive pressure from being applied to the other prismatic battery cells whose internal pressure has not increased even if the predetermined prismatic battery cell expands in the thickness direction.

  Preferably, the connecting member is a connecting rod having a rod shape, and each of the prismatic battery cells is provided with a restraining protrusion through which the connecting rod is inserted. Are provided with cylindrical metal collars having the same length as the thickness of the prismatic battery cells and fitted to the connecting rods. According to this configuration, since the rectangular battery cell is restrained in the thickness direction by the metal collar, expansion due to an increase in internal pressure of the predetermined rectangular battery cell is suppressed. Further, it is possible to prevent an excessive pressure from being applied to the other prismatic battery cells whose internal pressure has not increased even if the predetermined prismatic battery cell expands in the thickness direction.

  Preferably, a positioning member for positioning and fixing any one of the prismatic battery cells stacked between the pair of restraining plates is attached to the connecting member. In this way, since any one of the rectangular battery cells is fixed to the connecting rod, the expansion of the other rectangular battery cells is suppressed by the fixed rectangular battery cell.

  Preferably, an expansion suppression plate fixed by any one of the connecting members is disposed between the adjacent rectangular battery cells, and any one of the rectangular shapes adjacent to the expansion suppression plate is disposed. The battery cell is pressed. By disposing such an expansion restraining plate between the square battery cells, the expansion of each square battery cell is more reliably inhibited.

  Preferably, the expansion restraining plate is provided with a slit for enhancing the elastic deformability of the central portion thereof, for example, a slit arranged in parallel in the width direction and having an intermediate portion in the height direction communicated with each other. ing. If it does in this way, when expansion of a square battery cell will be settled, there exists an advantage which an expansion | swelling suppression plate restore | restores in an original flat plate shape reliably.

  Preferably, the battery pack including an assembled battery in which the plurality of rectangular battery cells having a flat plate shape are stacked in the thickness direction includes: (a) Among the square battery cells stacked in the thickness direction; A first fixing device for fixing a part of the square battery cells including both ends of the battery cell to a support member for supporting the assembled battery, (b) a retainer member parallel to the longitudinal direction of the assembled battery, and (c) A second fixing device for fixing the retainer member to the prismatic battery cell fixed to the support member by the first fixing device; and (d) between the square battery cells to which the retainer member is fixed by the second fixing device. And a pressing member that is interposed between the other prismatic battery cell positioned and the retainer member and presses and fixes the other prismatic battery cell to the support member. In this way, since some of the square battery cells including both ends of the square battery cells stacked in the thickness direction are directly fixed to the support member, the square battery can be used without using a restraining plate. The expansion of the cells is suppressed, and the prismatic battery cells are pressed against the support member by the pressing member provided on the retainer member, thereby preventing the prismatic battery cells from being displaced. In addition, since the restraint plate is not required and the number of fastening bolts for fixing the assembled battery is reduced, the assembly workability is improved and the assembly cost is reduced.

1 is an exploded perspective view illustrating a configuration of a battery pack according to an embodiment of the present invention. FIG. 2 is a perspective view showing a pair of prismatic battery cells adjacent to each other among the prismatic battery cells constituting the battery pack used in the battery pack of FIG. 1. It is a perspective view which shows the assembled battery used for the battery pack of FIG. It is side surface sectional drawing which shows the structure of the assembled battery of FIG. It is a cross-sectional view of the battery pack of FIG. It is a perspective view of the principal part of the assembled battery in the battery pack of FIG. FIG. 5 is a side sectional view showing a main part of an assembled battery according to another embodiment of the present invention, corresponding to FIG. 4. It is a top view which shows the principal part of the assembled battery in the other Example of this invention. It is side surface sectional drawing which shows the example which shows the principal part of the assembled battery in the other Example of this invention. It is principal part sectional drawing explaining the connection structure between the connection rod and intermediate | middle restraint plate in the assembled battery of the Example of FIG. It is a perspective view which decomposes | disassembles and shows a part in order to demonstrate the structure which restrains a prismatic battery cell in the assembled battery in the other Example of this invention. It is a disassembled perspective view which expands and shows the principal part of the Example of FIG. It is principal part sectional drawing explaining the structure which restrains a prismatic battery cell in the assembled battery in the other Example of this invention. It is a perspective view which decomposes | disassembles and shows a part in order to demonstrate the principal part of the structure which restrains a prismatic battery cell in the assembled battery in the other Example of this invention. It is sectional drawing which shows the principal part of the Example of FIG. It is a top view which shows schematically the battery pack of the Example of this invention. It is a perspective view which decomposes | disassembles and demonstrates the principal part of the battery pack of the Example of FIG. It is sectional drawing which shows the principal part of the battery pack of the Example of FIG. It is a top view which shows the principal part in the assembled battery of the other Example of this invention. It is a figure explaining the action | operation of an expansion suppression plate in the assembled battery of the Example of FIG. It is a cross-sectional view which shows the battery pack of the other Example of this invention. It is sectional drawing which expands and demonstrates the principal part of the Example of FIG. It is a perspective view which shows the edge part of the battery pack of the other Example of this invention. It is a perspective view which shows the principal part of a lower case in the battery pack of the other Example of this invention. It is sectional drawing which expands and shows the attachment structure of the lower case in the Example of FIG. It is a perspective view which expands and shows the attachment structure of the lower case in the Example of FIG. It is a top view which shows the connection bracket used for attachment of a lower case in the Example of FIG. It is a perspective view which shows the square-shaped battery cell used for the battery pack of the other Example of this invention. It is a perspective view which expands and shows the principal part of the square battery cell of FIG. It is a figure which decomposes | disassembles and shows the square-shaped battery cell and positioning piece of FIG. It is a perspective view which expands and shows the mounting structure of the square battery cell and positioning piece of FIG. It is sectional drawing of the side view which shows the structure of the assembled battery assembled using the square battery cell of FIG. It is a perspective view which shows the square-shaped battery cell used for the battery pack in the other Example of this invention. It is a perspective view which expands and shows the principal part of the square battery cell of FIG. It is sectional drawing of the side view which shows the structure of the assembled battery assembled using the square battery cell of FIG. It is a perspective view which decomposes | disassembles and shows an assembled battery in order to demonstrate the structure of the battery pack of the other Example of this invention. It is a perspective view which expands and shows the principal part structure for fixing the square battery cell of FIG. It is sectional drawing which expands and shows the principal part structure for fixing the square battery cell of FIG. It is a perspective view which expands and shows the principal part structure for fixing a square-shaped battery cell in the assembled battery of the other Example of this invention. It is sectional drawing which expands and shows the principal part structure for fixing the square battery cell of FIG. It is a perspective view which decomposes | disassembles and shows an assembled battery in order to demonstrate the structure of the battery pack of the other Example of this invention. It is a perspective view which decomposes | disassembles and shows the principal part structure for fixing the square battery cell of FIG. It is sectional drawing which decomposes | disassembles and shows the principal part structure for fixing the square battery cell of FIG. It is sectional drawing which shows the principal part structure for fixing the square battery cell of FIG. It is a side view which shows the principal part structure for fixing the square battery cell of FIG. It is a perspective view which decomposes | disassembles and shows an assembled battery in order to demonstrate the structure of the battery pack of the other Example of this invention. It is a perspective view which decomposes | disassembles and shows the principal part structure for fixing the square battery cell of FIG. It is a longitudinal cross-sectional view which shows the principal part structure for fixing the square battery cell of FIG. It is a cross-sectional view which shows the principal part structure for fixing the square battery cell of FIG. It is a perspective view which decomposes | disassembles and shows the principal part structure for fixing a square-shaped battery cell in the battery pack of the other Example of this invention. It is a cross-sectional view which shows the principal part structure for fixing the square battery cell of FIG. It is a side view which shows the principal part structure for fixing the square battery cell of FIG. In the battery pack of the other Example of this invention, it is a perspective view which shows the structure of an assembled battery. It is a perspective view which shows the principal part structure for fixing the square battery cell of FIG. It is a longitudinal cross-sectional view which shows the principal part structure for fixing the square battery cell of FIG. FIG. 56 is a longitudinal sectional view showing a main part configuration for fixing a prismatic battery cell in another embodiment of the present invention, and corresponds to FIG. 55. In the battery pack of the other Example of this invention, it is a perspective view which shows the principal part structure for fixing a square-shaped battery cell. FIG. 58 is a side view showing a configuration of a main part for fixing the prismatic battery cell of FIG. 57. FIG. 58 is a perspective view showing another example of a restraining band used for fixing the rectangular battery cell of FIG. 57. It is a longitudinal cross-sectional view which shows the principal part structure for fixing the lower part of a square-shaped battery cell in the battery pack of the other Example of this invention. FIG. 61 is a perspective view showing a lower case of the assembled battery case in the battery pack of FIG. 60. FIG. 61 is an exploded perspective view illustrating a main part configuration for fixing a lower part of a rectangular battery cell in the battery pack of FIG. 60. FIG. 61 is a cross-sectional view showing a main part of a fixing structure for fixing a positioning member used for fixing the lower part of the prismatic battery cell of FIG. 60 to the lower case. It is sectional drawing explaining the principal part of the structure which fixes the lower part of a square-shaped battery cell in the battery pack of the other Example of this invention. It is a perspective view which shows the positioning member used in order to fix a square battery cell in the Example of FIG. FIG. 65 is a plan view showing the positioning member of FIG. 64. In the Example of FIG. 64, it is a perspective view which shows the lower surface of the square battery cell fixed with a positioning member. In the battery pack of the other Example of this invention, it is a perspective view which decomposes | disassembles and shows the principal part structure which suppresses the expansion | swelling of the square battery cell laminated | stacked on the thickness direction. FIG. 69 is a cross-sectional view of the battery pack of FIG. 68. FIG. 69 is a bottom view showing an expansion suppression plate and a rectangular battery pack adjacent thereto in the battery pack of FIG. 68. FIG. 69 is a diagram showing a side surface of an expansion suppression plate in the battery pack of FIG. 68. In the battery pack of the other Example of this invention, it is a perspective view which shows the structure of an assembled battery. FIG. 73 is a perspective view showing a binding band coupling structure in the battery pack of the example of FIG. 72. In the battery pack of the other Example of this invention, it is the top view which notched a part which shows the structure of an assembled battery. FIG. 75 is a perspective view illustrating the configuration of prismatic battery cells arranged in the thickness direction in the example of FIG. 74. 74 is a perspective view illustrating a configuration of a connecting rod that connects a pair of restraining plates abutted against both end portions of the prismatic battery cells arranged in the thickness direction in the embodiment of FIG. 74. FIG. In the example of FIG. 74, it is a figure which shows the state by which the gas discharge cylinder of the square battery cell and the connection cylinder of the connecting rod were connected via the connection hose. It is a perspective view which shows the communicating pipe and discharge pipe connected to the edge part of a connecting rod. It is a perspective view which decomposes | disassembles and shows the structure of the battery pack of the other Example of this invention. FIG. 80 is a cross-sectional view of the battery pack of FIG. 79. FIG. 80 is a plan view showing the prismatic battery cells used in the battery pack of FIG. 79 apart from each other. FIG. 80 is a cross-sectional view represented by a plane including an axis of the positioning protrusions in order to enlarge and show a fitting state of the pair of positioning protrusions provided on the combination surface of the pair of prismatic battery cells in FIG. 79; . 79 is a cross-sectional view represented by a plane orthogonal to the axis of the positioning protrusions in order to enlarge and show the fitting state of the pair of positioning protrusions provided on the combination surface of the pair of rectangular battery cells in FIG. is there. FIG. 80 is an enlarged cross-sectional view illustrating a structure of a connection terminal provided on an upper side surface of the prismatic battery cell of FIG. 79. FIG. 80 is a partially cutaway view showing a fixing structure in which one end portion in the width direction of the rectangular battery cell of FIG. 79 is fixed to a lower case. FIG. 80 is a partially cutaway view showing a fixed structure in which the other end portion in the width direction of the rectangular battery cell of FIG. 79 is fixed to the lower case. It is a perspective view which shows the connection structure of the connection terminal provided in the square battery cell laminated | stacked in the thickness direction in the battery pack of the other Example of this invention. It is a perspective view which shows the square-shaped battery cell used for the battery pack of the other Example of this invention. FIG. 89 is a plan view illustrating the rectangular battery packs stacked in the thickness direction in the embodiment of FIG. FIG. 89 is a diagram showing a mounting structure of an elastic member provided on the upper part of the combination surface of the prismatic battery pack in the example of FIG. 88. In the battery pack of the other Example of this invention, it is the figure which notched some explaining the fixing structure of a square-shaped battery cell. In the battery pack of the other Example of this invention, it is a perspective view explaining the fixing structure utilized in order to fix another part of the square battery cell laminated | stacked in the thickness direction. It is a perspective view explaining the structure of the retainer used for FIG. It is a figure which shows the fixation structure of the square battery cell fixed with a fixing volt | bolt among the square battery cells used for FIG. 92, and the fixation structure of a retainer. It is a figure which shows the fixation structure of the square battery cell fixed by the retainer among the square battery cells used for FIG.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a perspective view showing an example of an assembly structure of a battery device, that is, a battery pack according to the present invention. This battery pack is made of a flat, rectangular parallelepiped, flat plastic, and has a plurality of battery cases each containing therein an electrolyte and an electrode plate that are separated by an internal partition and constitute a secondary battery. It has a battery module, that is, a battery pack 10 in which a plurality of battery cells 11 are integrally laminated in the thickness direction, and a battery pack case 20 in which the battery pack 10 is accommodated. The assembled battery 10 is arranged so that the longitudinal direction thereof is the width direction of the vehicle, for example, in a space provided in the lower body of the rear seat.

  In the assembled battery 10, the respective square battery cells 11 are laminated in such a manner that they are in alignment with each other and are butted in the thickness direction. As shown in FIG. 2, a pair of positioning protrusions 11a is provided on one diagonal line on one of the opposing surfaces, that is, the combined surfaces, in which each square battery cell 11 is combined with another square battery cell 11 adjacent thereto. A pair of positioning recesses 11b are provided at an appropriate interval in the other diagonal direction. Further, a pair of positioning recesses into which the positioning protrusions 11a and the positioning recesses 11b provided on the surface of the other opposing prismatic battery cells 11 are respectively fitted on the other combination surface in each square battery cell 11 11b and positioning protrusion 11a are provided at appropriate intervals in the diagonal direction.

  Therefore, when a pair of square battery cells 11 are abutted with each other, a pair of positioning protrusions 11 a provided on the surface of one square battery cell 11 are provided on the surface of the other square battery cell 11. The positioning recesses 11b are engaged with each other. As a result, the pair of prismatic battery cells 11 that are faced to each other are positioned with respect to each other in the height direction and the width direction, and the arrangement posture is matched.

  For example, as shown in FIG. 6, a pair of positive and negative terminals respectively projecting from upper portions of a pair of side surfaces of adjacent square battery cells 11 is provided on both side surfaces of adjacent square battery cells 11. In order to electrically connect the connection terminals T in series, each end of the bus bar 15 fitted to the connection terminal T is fastened by a nut 16. Thereby, each square battery cell 11 which comprises the assembled battery 10 is electrically connected in series.

  FIG. 3 is a perspective view of the assembled battery 10, and FIG. 4 is a cross-sectional view of the assembled battery 10. A relatively high-stiffness metal restraining plate 12 is abutted against each of the prismatic battery cells 11 stacked to form the assembled battery 10 at the end. Each constraining plate 12 has a rectangular portion similar to that of the rectangular battery cell 11 against which the constraining plate 12 is abutted. A pair of upper projecting portions 12a projecting in a circular shape is provided at an appropriate interval in the width direction, and a pair of lower projecting portions projecting in a semicircular shape downward is formed on the lower edge of the rectangular portion. 12b is provided at an appropriate interval in the width direction. Each constraining plate 12 is provided with a flange portion 12d extending in the opposite direction to the prismatic battery cell 11 against which it is abutted.

  The pair of restraining plates 12 are long connecting members arranged on both sides of the prismatic battery cell 11 so that the prismatic battery cell 11 between them is pressed, that is, a preload is applied. Are connected to each other. That is, the pair of upper projecting portions 12a of each restraining plate 12 disposed at both ends of the assembled battery 10 are in a state of projecting upward from the upper surfaces of the abutted square battery cells 11, respectively. Between the upper projecting portions 12a facing each other in the restraint plate 12, restraint rods, that is, connecting rods 13 that are parallel to the stacking direction of the respective rectangular battery cells 11 are spanned. The end portions of the connecting rods 13 are inserted through the upper protrusions 12a of the restraining plates 12, and the nuts 14 are screwed into the end portions of the connecting rods 13, respectively. Are connected by each connecting rod 13, and the rectangular battery cells 11 between the pair of restraining plates 12 are pressed against each other by a predetermined preload. In addition, the pair of lower protrusions 12b of each restraint plate 12 disposed at both ends of the assembled battery 10 are in a state of protruding downward from the lower side surface of each abutted square battery cell 11, The connecting rods 13 are also installed between the lower projecting portions 12 b facing each other in the restraining plates 12 along the stacking direction of the rectangular battery cells 11. The end of each connecting rod 13 is inserted through the lower protrusion 12 b of each restraining plate 12, and a nut 14 is screwed into the end of each connecting rod 13.

  The pair of restraining plates 12 are moved in a direction approaching each other by tightening nuts 14 at respective ends of the connecting rods 13, and the stacked square battery cells 11 are mutually connected. Press in the thickness direction so that they are in close contact. Thereby, even if the internal pressure of any square battery cell 11 rises, the battery case in each square battery cell 11 is prevented from expanding.

  FIG. 5 shows a cross section of the battery pack. As shown in FIGS. 1 and 5, an assembled battery case 20 in which the assembled battery 10 is accommodated is integrally joined to a lower case 21 and the lower case 21 that are press-formed from a single metal plate. And an upper case 22. The lower case 21 has a bottom surface portion 21a placed on the vehicle body of the automobile, and each side edge of the bottom surface portion 21a is a side surface portion that extends slightly inclined outward and upward. 21b is continuous. Each side surface portion 21b is continuously provided with a lower flange portion 21c extending substantially horizontally toward the outside.

  The upper case 22 has a horizontal upper surface portion 22a that covers the pair of connecting rods 13 disposed on the upper portion of the assembled battery 10, and an upper side surface that extends substantially vertically downward from each side edge of the upper surface portion 22a. And a step portion 22c extending horizontally from the upper side surface portion 22b. Each step portion 22c is continuously provided with a side surface portion 22d extending vertically downward. And the upper side flange part 22e extended substantially horizontally toward the outer side is respectively continued under the side part 22d, and each upper side flange part 22e is each lower side flange part 21c of the lower case 21. Are combined with each other.

  Each lower flange portion 21c of the lower case 21 is provided with a plurality of bolt through holes 21e at appropriate intervals, and each upper flange portion 22e of the upper case 22 is also provided with each lower flange portion 21c. Bolt through holes 22f that are aligned with the bolt through holes 21e of the side flange portion 21c are provided. Bolts 23 are inserted into the bolt through holes 21e and 22f aligned with each other.

  As shown in FIG. 5, the lower case 21 is attached to a vehicle body, for example, a rear floor panel, in a hybrid vehicle, and a recess into which the lower case 21 is fitted in a vehicle body portion to which the lower case 21 is attached. 30 is provided. Each side of the recess 30 is provided with a support portion 32 against which the lower flange portion 21c provided in the lower case 21 is abutted, and each support portion 32 has a lower flange portion. Bolts 23 that pass through 21c pass through, and nuts 25 are screwed to the bolts 23, respectively.

  The assembled battery 10 is placed on each side surface portion 21b of the lower case 21, and each lower connection rod 13 is surrounded by the bottom surface portion 21a and each side surface portion 21b of the lower case 21. Placed in the designated area. And the upper case 22 is arrange | positioned so that the assembled battery 10 mounted on the lower case 21 may be covered, and the upper flange part 22e of the upper case 22 is faced | matched by the lower flange part 21c of the lower case 21. Thus, the lower flange portion 21c and the upper flange portion 22e that are abutted with each other are integrally connected together with the support portion 32 of the vehicle body by the bolt 23 and the nut 25.

  An appropriate cushioning material such as a rubber pad may be provided between the bottom surface of the concave portion 30 of the vehicle body and the bottom surface portion 21a of the lower case 21.

  Between each step portion 22c of the upper case 22 and the upper surface of the prismatic battery cell 11 in a stacked state, a long elastic member 24 extending over the entire length of the prismatic battery cell 11 in the stacking direction is provided. ing. Each elastic member 24 is configured by elastic rubber having a rectangular cross section, and each step portion 22c of the upper case 22 presses the upper surface of all the rectangular battery cells 11 via the elastic member 24, respectively. doing. Therefore, all the square battery cells 11 are respectively supported by the side surfaces 21b in the lower case 21, and the load of each square battery cell 11 compresses the side surfaces 21b of the lower case 21. Thus, it is transmitted to the recess 30 of the vehicle body.

  Further, each step portion 22c of the upper case 22 that presses the upper surface of all the rectangular battery cells 11 has an upper flange portion 22e attached to the support portion 32 of the vehicle body by a bolt 23 via each side surface portion 22d. Therefore, a downward pulling force is applied to each step 22c with respect to each side surface 22d, and each step 22c presses each square battery cell 11 by this pulling force.

  Thus, since the assembled battery 10 is supported by the vehicle body in a state where it is dispersed in the compressive force on the lower case 21 and the tensile force on the upper case 22, the rigidity of the lower case 21 and the upper case 22 is increased. Each can be reduced. As a result, the lower case 21 and the upper case 22 can be reduced in thickness and weight. That is, the square battery cells 11 pressed against each other are securely attached to the assembled battery case 20 having the lower case 21 and the upper case 22, thereby preventing the prismatic battery cells 11 from being displaced due to vibration or the like. In addition, the assembled battery case 20 can be reduced in weight.

  The assembled battery 10 supported by the lower case 21 and the upper case 22 is press-contacted with the step portions 22c of the upper case 22 via a pair of elastic members 24 each having a rectangular cross section. The battery 10 is stably held in the assembled battery case 20. Each elastic member 24 has an appropriate length in the vertical direction, and even when a large upward pressure is applied to the lower case 21 due to vibration, impact, etc. applied to the vehicle body, Since the pressure is absorbed by each elastic member 24, the upward movement amount of the assembled battery 10 is suppressed. Also by this, the rigidity of the assembled battery case 20 can be suppressed low, and the assembled battery case 20 itself can be reduced in thickness and weight. Further, it is not necessary to strongly reinforce the entire assembled battery 10.

  A space surrounded by the bottom surface portion 21 a and the side surface portions 21 b exists below the assembled battery 10 below the lower case 21 in the assembled battery case 20. A cooling air passage for cooling the rectangular battery cell 11 is used. Similarly, a space surrounded by the upper surface portion 22 a and the upper side surface portion 22 b exists above the assembled battery 10 in the upper part of the upper case 22, and the space is each square battery of the assembled battery 10. In order to cool the cell 11, a cooling air passage is provided. A slight gap (not shown) is provided between each of the square battery cells 11 so that cooling air is introduced through one of the pair of spaces and discharged through the other. That is, by effectively using the space in the assembled battery case 20 as a passage for cooling air, each square battery cell 11 can be efficiently and reliably cooled.

  Each of the elastic members 24 is not limited to a configuration in which the rubber having a rectangular cross section is disposed over all the square battery cells 11 so as to press-contact the rubber with the upper surface of all the square battery cells 11. A configuration in which the battery pack 10 is partially disposed only at the center in the longitudinal direction so as to be in pressure contact with the upper surface of the prismatic battery cell 11 located at the center in the longitudinal direction, or a prismatic battery located at a plurality of locations in the longitudinal direction. It is good also as a structure etc. which are divided | segmented and arrange | positioned so that it may respectively press-contact with the cell 11. FIG.

  In addition, each elastic member 24 may be formed of a cylindrical or tubular synthetic rubber having a circular cross section with a hollow inside. Each elastic member 24 formed of such a cylindrical synthetic rubber is deformed so that the compression amount increases in proportion to the load when the applied load is small, but the appropriate range in which the applied load is increased. Then, it has the load-compression (FS) characteristic that the amount of compression hardly changes. Accordingly, even when an impact is applied to the assembled battery case 20 due to vibrations of the vehicle body and the integrated assembled battery 10 moves upward due to the impact, the assembled battery 10 is moved upward by the cylindrical elastic member 24. The movement of the battery 10 can be reliably absorbed, and there is no possibility that a large load is applied to the assembled battery 10 with respect to the upper case 22. Also by this, the rigidity of the upper case 22 can be reduced.

  Further, even when the cylindrical elastic member 24 that is a hollow body as described above is used, the configuration is not limited to the configuration in which all the rectangular battery cells 11 of the battery pack 10 are pressed into contact with each other. It is good also as a structure which press-contacts partially.

  Each square battery cell 11 in the assembled battery 10 is relatively strongly pressed and integrated by the pair of restraining plates 12 and the pair of upper and lower connecting rods 13. Even if an impact is applied to each square battery cell 11 due to an impact or the like, there is no possibility that the respective square battery cells 11 are displaced from each other. In addition, the rectangular battery cells 11 adjacent to each other in the assembled battery 10 are positioned by fitting the positioning protrusions 11a and the positioning recesses 11b provided on the respective surfaces to each other. It is even more reliably prevented from shifting in the vertical direction. As a result, as shown in FIG. 6, the bus bar 15 that connects the adjacent rectangular battery cells 11 is deformed, or the nut 16 that connects each end of the bus bar 15 to the side surface of each rectangular battery cell 11 is loosened. There is no fear.

  Next, another embodiment of the present invention will be described. In the following description, parts common to those in the above-described embodiment are denoted by the same reference numerals and description thereof is omitted.

  As shown in FIG. 7, the assembled battery 10 has a clamping margin between the upper portions of the restraining plates 12 by a pair of connecting rods 13 arranged on the upper side of the square battery cell 11 on the lower side of the square battery cell 11. You may make larger than the clamping allowance between the lower parts of each restraint plate 12 by a pair of connecting rod 13 arrange | positioned. Thereby, a pressure is also reliably applied to the upper part of the square battery cell 11 located in the center part of the assembled battery 10, and the square battery cell 11 located in the center part is prevented from being lifted upward. In this case, each square battery cell 11 is tightened between the upper parts of the respective restraining plates 12 by a pair of connecting rods 13 arranged on the upper side of the square battery cell 11 with the thickness of the upper part being larger than the thickness of the lower part. The margin and the clamping margin between the lower portions of the restraining plates 12 by the pair of connecting rods 13 disposed below the square battery cell 11 may be the same amount. Thus, you may make it the upper parts of each square-shaped battery cell 11 press strongly. Even in this case, the pressure is surely applied to the upper part of the square battery cell 11 located at the center of the assembled battery 10, and the prismatic battery cell 11 located at the center of the assembled battery 10 is prevented from shifting upward. Is done.

  Further, as shown in FIG. 8, the rectangular surface of the pair of restraining plates 12 that is press-contacted with the rectangular battery cell 11 bulges in the opposite direction to the rectangular battery cell 11 in the center in the width direction. In other words, it may be configured to be curved so as to be a concave surface in which the central portion is recessed in the width direction. Thereby, it is possible to apply a substantially uniform pressing force to each square battery cell 11 in the stacked state, and each square battery cell 11 is prevented from shifting in the width direction of the assembled battery 10.

  Furthermore, as shown in FIG. 9, the assembled battery 10 includes a plurality (three in this embodiment) of prismatic battery cells 11 in a stacked state that are separated into a plurality (12 in this embodiment). An intermediate restraint plate 17 may be provided. Each of the intermediate restraint plates 17 is configured in the same shape as the pair of restraint plates 12 provided at both ends of the assembled battery 10, respectively. The pair of upper projecting portions 17 a and the pair of lower projecting portions 17 b are respectively provided. Have. The connecting rods 13 are inserted into the upper projecting portions 17a and the lower projecting portions 17b, so that the upper projecting portions 17a and the lower projecting portions 17b of the intermediate restraint plate 17 are attached to the connecting rods 13, respectively. Yes. FIG. 10 is a cross-sectional view showing how the upper projecting portion 17 a and the connecting rod 13 are attached to the intermediate restraint plate 17. Cylindrical screw members 18 are fixed in advance by welding at positions where the intermediate restraint plates 17 of the respective connecting rods 13 are attached. The screw member 18 includes a flange portion 18a at one end portion, and a screw groove is formed on a peripheral surface opposite to the flange portion 18a. Then, the nut member 19 is screwed into the thread groove.

  A through hole 17c through which the connecting rod 13 is inserted is provided in the upper projecting portion 17a of the intermediate restraint plate 17, and the connecting rod 13 is inserted into each through hole 17c and attached to the connecting rod 13. The upper threaded portion 17 a is brought into contact with the flange portion 18 a of the screw member 18 attached to the connecting rod 13. In such a state, the nut member 19 is screwed into the screw groove of the screw member 18, and the upper protruding portion 17 a is sandwiched between the flange portion 18 a of the screw member 18 and the nut member 19. The upper protrusions 17a of the intermediate restraint plate 17 are fixed in a state where they are positioned.

  Similarly, the other upper projecting portions 17a and the lower projecting portions 17b of the intermediate restraint plate 17 are fixed to the connecting rods 13 while being positioned.

  As a result, the pair of upper and lower protrusions 17a and 17b of each intermediate restraint plate 17 is positioned on each pair of upper and lower connecting rods 13, and each intermediate restraint plate 17 is fixed at a predetermined position. . Thereby, in the region between each restraint plate 12 located at each end of the battery pack 10 and the intermediate restraint plate 17 adjacent to each restraint plate 12, and in the region between the adjacent intermediate restraint plates 17, A predetermined number of prismatic battery cells 11 are independently restrained while being pressed against each other.

  In the assembled battery 10 configured as described above, any one of the square batteries disposed in the region between the restraint plate 12 and the intermediate restraint plate 17 or the region between the pair of adjacent intermediate restraint plates 17. When the battery internal pressure of the cell 11 rises and the internal pressure of each other prismatic battery cell 11 does not rise, it is relatively in the region where the square battery cell 11 with the increased internal pressure is disposed. The small number of prismatic battery cells 11 suppresses the expansion of the prismatic battery cells 11.

  In the assembled battery 10, since the remaining battery capacity of each square battery cell 11 varies, the internal pressure of all the square battery cells 11 does not rise uniformly and expand. For this reason, when any one or a plurality of prismatic battery cells 11 expands in the thickness direction in the state where the intermediate restraint plate 17 is not provided, all the other non-expanded prismatic battery cells 11 expand. There is a possibility that the pressure by the square battery cell 11 applied is evenly dispersed and absorbed, and the pressing force for suppressing the expansion amount of the expanded square battery cell 11 may be reduced. However, as described above, by providing the intermediate constraining plate 17 and applying a pressing force independently to each of a relatively small number of the appropriate number of prismatic battery cells 11, any one of the prismatic batteries can be used. Even in the case where the cell 11 expands, the relatively small number of the square battery cells 11 restrained by the intermediate restraint plate 17 surely suppress the expansion of the square battery cells 11, and the expansion. It is possible to reliably prevent the battery performance from being deteriorated, the battery case from being destroyed, and the like due to the amount exceeding the allowable value.

  FIG. 11 is an exploded perspective view showing still another configuration example of the battery pack 10, and FIG. 12 is an exploded perspective view showing a main part thereof. The expansion of each rectangular battery cell 11 is suppressed along the side surface of each rectangular battery cell 11 that is in a state of being pressed against each other by a pair of restraining plates 12 connected by a pair of upper and lower connecting rods 13. A pair of expansion restraining plates 31 are arranged for the purpose. The expansion restraining plate 31 is formed of a strip-shaped steel plate, and a plurality of engaging hole portions 31a having a long hole shape in the vertical direction are formed in a portion facing the side surface of each rectangular battery cell 11. Each of the rectangular battery cells 11 stacked in the thickness direction is formed by punching at the same pitch. Each side surface of each square battery cell 11 is provided with a cross-sectional shape corresponding to the shape in which each engagement hole 31a is punched out, that is, a long engagement protrusion 11c.

  In such an assembled battery 10, all the rectangular battery cells 11 in a stacked state are constrained by a pair of restraining plates 12 and a pair of upper and lower connecting rods 13, and are attached to the side surfaces of the respective square battery cells 11. The expansion restraining plates 31 are respectively disposed along the engagement protrusions 11c provided on the side surfaces of the respective square battery cells 11 and are fitted into the engaging hole portions 31a provided on the respective expansion inhibiting plates 31. Is engaged. Each expansion restraining plate 31 is expanded by each of the rectangular battery cells 11 by engaging each engaging hole 31a with the engaging protrusion 11c of each rectangular battery cell 11. It is restrained by the pulling force of 31.

  For the purpose of maintaining the mutual engagement state between the engagement protrusions 11 c provided in each of the square battery cells 11 and the engagement holes 31 a provided in the expansion suppression plate 31, FIG. As shown in FIG. 4, each of the side edges along the longitudinal direction of the engagement protrusion 11c is provided with an engagement claw part 11d that prevents the engagement protrusion 11c from easily coming out of the engagement hole 31a. The engaging claw portion 11 d may be engaged with the inside of the engaging hole portion 31 a of the expansion suppression plate 31. The engagement claw portion 11d functions as a disengagement prevention device for preventing the engagement protrusion 11c from being disengaged from the engagement hole portion 31a.

  FIG. 14 is an exploded perspective view showing a main part of the assembled battery 10 showing another example of the expansion inhibiting plate 31, and FIG. 15 is a horizontal sectional view of that part. In order for the cooling air to flow in a state where the plurality of prismatic battery cells 11 are adjacent to each other in the thickness direction, an appropriate gap or gap S is provided between the side surfaces of each prismatic battery cell 11. On the surface of the expansion restraining plate 31 that faces the side surface of the rectangular battery cell 11, vertical ribs 31 b are inserted so as to be inserted into the gaps S that open on the side surface. The prismatic battery cells 11 are projected at intervals of the arrangement. Such an expansion suppression plate 31 is manufactured by, for example, extrusion molding of aluminum.

  In addition, each expansion | swelling suppression board 31 is not restricted to the structure engaged integrally with the side surface of all the square battery cells 11 in the assembled battery 10, It divides | segments into several and the some square battery cell in several area | regions You may make it each engage with 11 side surfaces. In this case, the number, region, and the like of the rectangular battery cells 11 with which the plurality of expansion suppression plates 31 are engaged are set in consideration of the strength, economy, and the like of the rectangular battery cells 11 and the expansion suppression plates 31.

  FIG. 16 is a schematic plan view showing still another configuration example of the battery pack according to the present invention, FIG. 17 is an exploded perspective view showing an essential part thereof, and FIG. 18 is a sectional view showing the essential part. In this battery pack, the assembled battery 10 is integrally fixed in a state where the respective square battery cells 11 are pressed against each other by a pair of restraining plates 12 and a pair of upper and lower connecting rods 13 connecting them. Each of the rectangular battery cells 11 is fixed to the lower case 21 by a plurality of pairs of expansion restraining members 32 provided on the lower flange portion 21c of the lower case 21 of the assembled battery case 20. ing. Each of the expansion suppression members 32 forming a pair is disposed along each side edge portion of the battery pack 10 with an appropriate interval therebetween, and the pair of expansion suppression members 32 are provided as one pair in the battery pack 10. The square battery cell 11 is fixed.

  As shown in FIG. 17, each expansion restraining member 32 is a longitudinal member having a U-shaped cross section made of synthetic resin or metal, and one side portion in the longitudinal direction is a lower flange of the lower case 21. The mounting portion 32 a is attached to the portion 21 c by a bolt 33 and a nut 34. Further, a groove 11e having a U-shaped cross section that opens outward in the width direction is formed at the lower part of each side surface of at least some of the plurality of prismatic battery cells 11 in the assembled battery 10, and the expansion The other end of the restraining member 32 is an engaging portion 32b that is fitted into the groove 11e. The engaging portion 32b is shaped to be positioned above the lower flange portion 21c of the lower case 21 at an appropriate distance by an amount substantially corresponding to the thickness of the bottom wall of the groove 11e.

  Then, the engaging portion 32b of the expansion restraining member 32 attached to the lower flange portion 21c of the lower case 21 is engaged in the groove portion 11e provided in the rectangular battery cell 11, and the bolt 33 and the nut 34 are engaged. Thus, each expansion suppression member 32 is fixed in a state where the groove 11e is pressed against the lower flange portion 21c of the lower case 21.

  As described above, each of the plurality of pairs of expansion suppression members 32 is engaged with the grooves 11e provided at the lower portions of the side surfaces of the prismatic battery cells 11 arranged at appropriate positions in the assembled battery 10, and the square shapes thereof. The square battery cell 11 is fixed by pressing the battery cell 11 against the bottom surface portion 21 a of the lower case 21. Therefore, any one of the rectangular battery cells 11 disposed in the region between the rectangular battery cells 11 fixed by the plurality of pairs of expansion suppression members 32 or the corner fixed by the pair of expansion suppression members 32. Even if any of the prismatic battery cells 11 arranged in the region between the battery cell 11 and the restraint plate 12 expands, the expansion is caused by the other region in the region where the prismatic battery cell 11 is disposed. All the square battery cells 11 are surely restrained. The expansion suppression member 32 functions as a fixing device that fixes the rectangular battery cell 11 to the lower case 21.

  Note that the number, the arrangement position, and the like of the rectangular battery cells 11 fixed by the plurality of pairs of expansion suppression members 32 are set in consideration of the strength, economy, and the like of the rectangular battery cells 11 and the expansion suppression member 32. .

  Moreover, in order to suppress the expansion | swelling of the square battery cell 11, it is good also as a structure shown in FIG. In this example, an expansion suppression plate for elastically pressing the square battery cells 11 is provided on at least one square battery cell 11 side of a pair of restraint plates 12 provided at the end of the assembled battery 10. 35 is attached. The expansion suppression plate 35 has a rectangular bottom surface similar to the combined surface of the prismatic battery cells 11, that is, the overlapping surface, and the side wall portion 35a is formed on the entire periphery of the peripheral portion or a part of the peripheral portion. Is provided. And the flange part 35b is provided in the perimeter of the side wall part 35a, or a part of the side wall part 35a. Between the flange part 35b of the expansion | swelling suppression plate 35 and the restraint plate 12, the sealing member 37 which has elasticity is interposed over the perimeter.

  A plurality of stepped bolts 36 are provided on the restraint plate 12 facing the expansion suppression plate 35 at equal intervals in the left-right direction, that is, in the width direction of the rectangular battery cell 11. Each stepped bolt 36 is supported so as to be slidable in the axial direction with respect to the restraint plate 12, and the tip of each stepped bolt 36 is screwed to the expansion suppression plate 35. A plurality of disc springs 38 are fitted between the expansion restraining plate 35 and the restraining plate 12 of each stepped bolt 36, and the expansion restraining plate 35 is separated from the restraining plate 12 by each disc spring 38. It is elastically biased in the direction.

  The expansion suppression plate 35 is abutted against the surface of the prismatic battery cell 11 located at one end when the prismatic battery cells 11 are stacked in a state of abutting against each other. When each square battery cell 11 is pressed by the pair of restraining plates 12, each disc spring 38 is compressed as shown in FIG. 20, and the expansion suppression plate 35 is square by the elastic force of each disc spring 38. It is press-contacted to the surface of the battery cell 11. Thereby, each square battery cell 11 arrange | positioned between the expansion | swelling suppression plate 35 and the restraint plate 12 located in the far side of this expansion | swelling suppression plate 35 will be in the state pressed mutually. As a result, even if the internal pressure of any one of the rectangular battery cells 11 is increased, the expansion is reliably prevented by the expansion suppression plate 35. In addition, even when the prismatic battery cell 11 is reduced in remaining battery capacity due to use, the state where all the prismatic battery cells 11 are pressed by the expansion restraining plate 35 biased by the plurality of disc springs 38 is maintained. In addition, the expansion of each square battery cell 11 can be stably suppressed over a long period of time. The expansion suppression plate 35, the stepped bolt 36, the disc spring 38, and the like function as a pressing device that constantly presses the prismatic battery cell 11 with a predetermined preload.

  FIG. 21 is a schematic configuration diagram showing another configuration example in which the assembled battery 10 in which each square battery cell 11 is restrained by a pair of restraining plates 12 is attached to the lower case 21 of the assembled battery case 20, FIG. It is sectional drawing which shows the principal part. In the lower case 21 of this embodiment, side portions 21b are provided substantially vertically along the left and right side edges of the bottom portion 21a, and a substantially horizontal lower flange portion is provided outside each side portion 21b. 21c is provided continuously. Since the seating surface which is the both ends of the bottom face of each square battery cell 11 is mounted on this horizontal lower flange part 21c, it functions as a battery mounting part.

  As shown in FIG. 22, each square battery cell 11 of the assembled battery 10 is provided with ears or legs 11f that protrude laterally at the lower portions of the side surfaces, and the legs 11f are provided in the legs 11f. The embedded nut 11g is provided in a vertical state by a technique such as insert molding or press fitting. The embedded nut 11g opens downward from the lower surface of the leg portion 11f. Each leg portion 11 f is placed on each lower flange portion 21 c of the lower case 21.

  The horizontal lower flange portion 21c of the lower case 21 is provided with a through hole facing the embedded nut 11g provided in each leg portion 11f of the rectangular battery cell 11, and each through hole and embedded nut is provided. Bolts 26 are respectively inserted into 11g from below the lower flange portion 21c and screwed to the embedded nuts 11g. Thereby, the assembled battery 10 is integrally fixed to the lower case 21.

  The assembled battery 10 fixed to the lower case 21 is covered with the upper case 22, and a plurality of bolts is provided in a state where the upper flange portion 22 e of the upper case 22 is abutted against the lower flange portion 21 c of the lower case 21. The upper flange portion 22e and the lower flange portion 21c are integrally connected by the nut 23 and the nut 25. Thus, the upper case 22 and the lower case 21 are integrally connected, and the assembled battery 10 is accommodated in the assembled battery case 20.

  An appropriate gap is formed between each side surface portion 22d of the upper case 22 and the side surface of each square battery cell 11 in the assembled battery 10, and terminals T, A bus bar 15, a wire harness (not shown), and the like are arranged. And since the leg part 11f of each square-shaped battery cell 11 is arrange | positioned under the gap | interval, and the leg part 11f is being fixed to the lower flange part 21c of the lower case 21 with the volt | bolt 26. The space in the lower case 21 can be used very effectively.

  Moreover, the leg portions 11f of each square battery cell 11 are fixed to the lower flange portion 21c of the lower case 21 by bolts 26 in the vicinity of the side surface portions 22d of the upper case 22, respectively. The lower case 21 is reinforced by the side portions 22 d of the upper case 22 integrated with the lower case 21 by the bolts 23 and the nuts 25. This also increases the rigidity of the lower flange portion 21c of the lower case 21 to which the assembled battery 10 is attached.

  In this case, the elastic member 24 provided between the step portion 22c of the upper case 22 and the upper surface of each square battery cell 11 of the assembled battery 10 has no fear of being applied with a load from the assembled battery 10, and is cooled. Since it only needs to function as a seal for forming a wind passage, a particularly strong elastic force is not required, and for example, a soft sponge or the like can be used.

  In addition, the configuration is not limited to the configuration in which all the square battery cells 11 constituting the assembled battery 10 are fixed to the lower case 21, but the lower case 21 is configured using several bolts 26 selected in advance using the bolts 26. You may make it fix to.

  Furthermore, as shown in FIG. 23, each end of the lower case 21 and the upper case 22 is opened to a shape that matches the outer shape of each restraint plate 12, and each restraint plate 12 is fitted into the opening. You may make it make it.

  Furthermore, as shown in FIG. 24, each square battery cell 11 is fixed to the lower flange portion 21 c of the lower case 21 with a bolt 26 in a state of being restrained by a pair of restraining plates 12. Furthermore, you may make it provide the several attachment part 21d for attachment of the lower case 21 with respect to a vehicle body continuously on the outer side of the horizontal lower flange part 21c which functions as a battery mounting part. Each attachment portion 21d is provided at an appropriate position in the longitudinal direction of the lower flange portion 21c, and each of the attachment portions 21d is directed outward through a portion vertically bent downward from the lower flange portion 21c. It extends almost horizontally. A through hole 21e is provided at the center of the attachment portion 21d.

  FIG. 25 is a cross-sectional view showing a mounting state of the mounting portion 21d of the lower case 21, and FIG. 26 is a perspective view showing an essential part thereof. The attachment portion 21d of the lower case 21 is attached to a predetermined position of the vehicle body via a connection bracket 29 shown in detail in FIG. The connecting bracket 29 has a flat plate portion 29a disposed below the bottom surface portion 21a of the lower case 21, and a fitting groove portion 29b provided continuously to the flat plate portion 29a so as to fit the mounting portion 21d. doing. The flat plate portion 29a is continuous with the bottom surface of the fitting groove portion 29b and has a width dimension larger than that of the fitting groove portion 29b. Each side surface of the fitting groove portion 29b is abutted against the side surface portion 21b of the lower case 21, and is bent outward at a right angle along the side surface portion 21b.

  The bottom surface of the fitting groove 29b and the flat plate portion 29a are fixed to the lower surface of the mounting portion 21d and the bottom surface portion 21a of the lower case 21 by welding, respectively, and aligned with the through hole 21e provided in the mounting portion 21d. A through hole 29c is provided. Further, on the bottom surface of the fitting groove portion 29b located between the mounting portion 21d and the bottom surface portion 21a of the lower case 21, a bolt 26 for fixing the rectangular battery cell 11 to the lower flange portion 21c of the lower case 21. The bolt passage hole 29e is provided so that can pass through.

  The lower case 21 is brought into an aligned state by abutting the through hole 21e provided in the mounting portion 21d and the through hole 29c provided in the connecting bracket 29 with a through hole provided at a predetermined position of the vehicle body in an aligned state. The bolts 23 are inserted into the through-holes 21e and 29c and the nuts 25 are screwed together to be attached to the vehicle body.

  Thus, the attachment portion 21d provided on the lower case 21 is attached to the vehicle body, and the connection bracket 29 is attached between the attachment portion 21d and the bottom surface portion 21a of the lower case 21. Therefore, the side portions 21b of the lower case 21 are securely fixed without vibrating so as to approach and separate from each other. Therefore, even if a load in the vertical direction is applied to each of the rectangular battery cells 11 that are respectively attached to the lower flange portion 21c by the bolts 26, there is no possibility that the lower case 21 is deformed so as to wave, The square battery cell 11 is stably held by the lower case 21.

  When pressing the square battery cell 11 stacked in the thickness direction between the pair of restraint plates 12, for example, as shown in FIG. A plurality of metal-shaped positioning pieces 39 may be respectively fitted. These positioning pieces 39 function as positioning members for the prismatic battery cells 11, and are positioned above and below the positions corresponding to the partition walls separating the plurality of battery cases provided inside the prismatic battery cells 11. Each is attached. As shown in FIGS. 29 to 31, the positioning piece 39 is configured in a band plate shape extending along the thickness direction of the upper surface and the lower surface of the prismatic battery cell 11, and each end portion is configured to be a prismatic battery cell 11. Are bent at substantially right angles in the same direction along the respective surfaces. And the circular engagement hole 39a is provided in the said edge part along each surface of the square battery cell 11, respectively.

  Engaging protrusions 11h that engage with engaging holes 39a provided at the end of the positioning piece 39 are provided on the lower and upper portions of each surface of the prismatic battery cell 11 to which the positioning piece 39 is attached, respectively. Yes. Each engaging protrusion 11h provided on the lower surface of the prismatic battery cell 11 has a cylindrical shape that is inclined so that the tip end surface protrudes sequentially toward the upper side. Similarly, each of the engaging projections 11h provided on the upper surface has a cylindrical shape that is inclined so that the tip end surface protrudes sequentially toward the lower side.

  The positioning piece 39 is mounted at the same position on the upper and lower sides of the rectangular battery cells 11 adjacent to each other in the thickness direction. At this time, each end of the positioning piece 39 shaped along each upper or lower surface of the prismatic battery cell 11 slides along the inclined tip surface of the engaging protrusion 11h, and the positioning piece 39 Engagement projections 11 h are fitted into engagement holes 39 a provided at the ends, and the ends of the positioning piece 39 are fixed to the upper or lower surface of the prismatic battery cell 11.

  Since the positioning pieces 39 are respectively attached to the same positions of the respective square battery cells 11, in a state where all the square battery cells 11 are pressed between the pair of restraining plates 12, FIG. As shown, the positioning pieces 39 provided at the upper part of each adjacent rectangular battery cell 11 and the positioning pieces 39 provided at the lower part of each adjacent rectangular battery cell 11 are in contact with each other and pressed against each other. It is done.

  Thereby, all the positioning pieces 39 arranged along the thickness direction of the prismatic battery cell 11 are positioned between the restraint plates 12, and each square shape to which the pair of upper and lower positioning pieces 39 are attached. Each of the battery cells 11 is also positioned and fixed. As a result, even when the internal pressure of any of the rectangular battery cells 11 rises and expands, the rectangular battery cell 11 disposed adjacent to the rectangular battery cell 11 is fixed in a positioned state. Thus, the expansion of the prismatic battery cell 11 whose internal pressure has increased is suppressed. Moreover, when the internal pressure of many square battery cells 11 rises, it is prevented that an excessive pressure is applied to the square battery cell 11 in which the internal pressure does not increase.

  In the battery pack shown in FIG. 33 and FIG. 34, each pair of constraining protrusions is provided on the upper surface and the lower surface of each square battery cell 11 without providing the positioning piece 39 in each square battery cell 11 as described above. 11x is provided, and the connecting rod 13 is inserted through each of the restraining protrusions 11x. Each constraining protrusion 11x is provided with a through-hole through which each connecting rod 13 is inserted, and a metal cylindrical collar 11z fitted to each connecting rod 13 is respectively inserted into each through-hole. It is inserted by press-fitting or insert molding. Each collar 11z has a length substantially the same as the thickness of each prismatic battery cell 11, and abuts against the collar 11z provided in each adjacent prismatic battery cell 11.

  As shown in FIG. 35, each of the square battery cells 11 is stacked in the thickness direction in the collars 11z inserted into the pair of upper and lower restraining protrusions 11x. Each of the pair of connecting rods 13 is inserted. Further, as in the above-described embodiment, the end portions of the connecting rods 13 are fixed to the pair of restraining plates 12 respectively abutted against the rectangular battery cells 11 positioned at both ends in the stacking direction by the nuts 14 respectively. Has been.

  As a result, the metal collars 11z provided on the restraining protrusions 11x of the respective square battery cells 11 have the same length as the thickness of the square battery cell 11 and are adjacent to each other. Each of the prismatic battery cells 11 is in a state of being abutted against other metal collars 11z provided on the restraining protrusions 11x of the prismatic battery cells 11 and between the pair of restraining plates 12, respectively. Fixed in a positioned state. As a result, even when the internal pressure of any square battery cell 11 increases and expands, the square battery cell 11 disposed adjacent to the square battery cell 11 is fixed in a positioned state. Thus, the expansion of the prismatic battery cell 11 whose internal pressure has increased is suppressed. Moreover, when the internal pressure of many square battery cells 11 rises, it is prevented that an excessive pressure is applied to the square battery cell 11 in which the internal pressure does not increase.

  FIG. 36 is an exploded perspective view showing a configuration example in the case of restraining the prismatic battery cells 11 at predetermined positions in the arrangement direction using the pair of upper connecting rods 13 restraining the pair of restraining plates 12, and FIG. FIG. 38 is a cross-sectional view of the main part, with the main part disassembled. Positioning plates 41 are respectively attached to the upper and lower surfaces of the prismatic battery cells 11 located at predetermined positions among the plurality of prismatic battery cells 11 arranged between the pair of restraint plates 12.

  The positioning plate 41 is a long metal strip having a width dimension similar to the thickness of the prismatic battery cell 11 and bent in a trapezoidal shape, and extends along the upper and lower surfaces of the prismatic battery cell 11. Are arranged respectively. At both ends of the positioning plate 41, fitting groove portions 41a that are parallel to the width direction of the rectangular battery cell 11 and open downward are provided.

  A pair of fitting protrusions 11k (see FIGS. 37 and 38) each protruding in a flat rectangular parallelepiped shape are provided on the upper surface of the rectangular battery cell 11 so as to be fitted into the fitting grooves 41a. ing. Engagement pieces 41b are provided on both end surfaces of the positioning plate 41 so as to be able to come into contact with the side surfaces of the respective fitting protrusions 11k fitted in the fitting grooves 41a.

  A connecting portion 41c positioned above each fitting groove 41a is provided at the center of the positioning plate 41 excluding each fitting groove 41a. A pair of through-holes 41d are arranged in the connecting portion 41c with an appropriate interval in the width direction of the rectangular battery cell 11, and the bottom surface of the connecting portion 41c is a nut concentric with each through-hole 41d. 41e is fixed.

  Such positioning plates 41 are provided on the upper surface of a plurality (three in this embodiment) of the rectangular battery cells 11 arranged at a predetermined number of the plurality of rectangular battery cells 11 stacked in the thickness direction. Each is attached to the lower surface.

  The upper and lower (not shown) connecting rods 13 that restrain the pair of restraining plates 12 are opposed to the positioning plates 41 respectively attached to the prismatic battery cells 11. A connecting plate 42 is attached across the pair of connecting rods 13. The end of each connecting plate 42 is attached to the surface of each connecting rod 13 by arc welding. Each connecting plate 42 is provided with a long hole 42a that is long in the width direction of the connecting plate 42, that is, in the thickness direction of the rectangular battery cell 11, at a position facing each through hole 41d provided in each positioning plate 41. ing. Then, the bolts 43 are inserted into the respective long holes 42a and screwed to the respective nuts 41e provided on the positioning plate 41, so that the positioning plate is attached to the connecting plates 42 attached to both the connecting rods 13. 41 are attached and fixed in a state in which the position with respect to the connecting plate 42 is adjusted.

  Thereby, in all the square battery cells 11 which are pressed by the pair of restraining plates 12, the positioning plate 41 attached to the square battery cell 11 is positioned on the connection plate 42 attached to the connection rod 13. Therefore, the rectangular battery cell 11 to which the positioning plate 41 is attached is securely fixed without moving. Therefore, the expansion of the other rectangular battery cells 11 can be suppressed by the rectangular battery cells 11.

  The perspective view of FIG. 39 and the cross-sectional view of FIG. 40 show that the positioning members 44 are respectively attached to the fitting protrusions 11k provided on the upper surface of the prismatic battery cell 11, and each positioning member 44 is connected to one connecting rod. 13 shows an example in which each is attached. The positioning member 44 is provided on the upper surface of the fitting groove 44a, and the fitting groove 44a opened downward so as to be fitted to the fitting protrusion 11k provided on the upper surface of the rectangular battery cell 11. And a mounting portion 44b.

  The fitting groove 44 a is provided along the upper surface of the rectangular battery cell 11. The attachment portion 44b is a member bent from a metal plate by press molding or the like, and is configured to bend into a portion along the upper surface of the fitting groove portion 44a and a portion along the connecting rod 13, A portion along the upper surface of the fitting groove 44a is attached to the upper surface of the fitting groove 44a by arc welding. A pair of long holes 44c extending along the connecting rods 13 are provided at portions along the connecting rods 13 at appropriate intervals in the horizontal direction.

  A pair of bolts 45 is attached to each connecting rod 13 at a position corresponding to the rectangular battery cell 11 to which the positioning member 44 is attached. Each bolt 45 is arranged in a horizontal state perpendicular to each connecting rod 13 with an appropriate interval in the axial direction of the connecting rod 13. The pair of bolts 45 are held on the peripheral surface of the connecting rod 13 by mounting pieces 43 fixed to the peripheral surface of the connecting rod 13 by arc welding.

  The pair of bolts 45 fixed to the connecting rod 13 are inserted into the respective long holes 44c of the attachment portion 44b of the positioning member 44 attached to the prismatic battery cell 11, so that the positioning member 44 has a predetermined rectangular shape. It adjusts so that it may fit in the fitting protrusion part 11k of the battery cell 11. FIG. Then, the nuts 46 are screwed to the respective bolts 45 attached to the connecting rod 13, whereby the positioning member 44 attached to the rectangular battery cell 11 is fixed at a predetermined position of the connecting rod 13. Thereby, the square battery cell 11 attached to the positioning member 44 is fixed in a non-moving state, and the expansion of other square battery cells 11 is suppressed by the square battery cell 11.

  In FIG. 41, a support plate 47 that holds the pair of bolts 45 vertically on both sides of the connecting rod 13 is attached to the lower peripheral surface of the connecting rod 13 by arc welding, and the positioning member 48 is attached by each bolt 45 of the support plate 47. An embodiment is shown which is fixed.

  As shown in FIGS. 42 and 43, the positioning member 48 is fitted to the upper peripheral surface of the connecting rod 13 and abuts on portions of the support plate 47 located on both sides of the connecting rod 13. In addition, long holes 48a into which the bolts 45 are inserted are provided in portions that abut against the support plate 47 in a state along the axial direction of the connecting rod 13, and both sides of the connecting rod 13 in the positioning member 48. A pair of engaging pieces 48b that sandwich the rectangular battery cell 11 in the thickness direction are provided on the upper portion of the predetermined rectangular battery cell 11, respectively.

  Each positioning member 48 is attached in advance to a predetermined position of each connecting rod 13, and the long hole 48 a of the positioning member 48 is inserted into each bolt 45 supported by each support plate 47. Then, the positioning member 48 is positioned with respect to the support plate 47 so that each engaging piece 48b of the positioning member 48 is engaged with the upper part of the prismatic battery cell 11, and the nut 46 is screwed to each bolt 45. By being coupled, the positioning member 48 is fixed to the support plate 47. As a result, as shown in FIGS. 44 and 45, the positioning member 48 is fixed to the support plate 47 fixed to the connecting rod 13, and the rectangular battery cell 11 is fixed by the positioning member 48. .

  46 and 47 show an embodiment in which a through hole 51a is provided at a predetermined position of the pair of connecting rods 13 in the central portion of the connecting plate 51 provided in the installed state, and a positioning plate 52 is attached on the connecting plate 51. ing. The positioning plate 52 is fitted into the through-hole 51a and has an elongated cross-sectional engagement tube that is fitted into a long-hole engagement protrusion 11k provided on the upper part of the prismatic battery cell 11. A portion 52a is provided.

  The connection plate 51 is provided with a pair of bolts 45 vertically with the head portion on the lower side, with the through hole 51a interposed therebetween. The positioning plate 52 is provided with long holes 52b along the connecting rod 13 on both sides of the engaging cylinder portion 52a. The bolts 45 provided on the connecting plate 51 are inserted into the long holes 52b, respectively. Is done. The nuts 46 are screwed to the respective bolts 45 inserted through the respective long holes 52b, and the positioning plate 52 is fixed to the connecting plate 51 as shown in FIGS. Then, the prismatic battery cell 11 is fixed by fitting the engagement cylindrical portion 52 a of the positioning plate 52 to the engagement protrusion 11 k provided on the upper surface of the prismatic battery cell 11.

  50 to 52 show an embodiment in which a positioning member 55 is attached to each connecting rod 13 and one rectangular battery cell 11 is fixed by each positioning member 55. Each positioning member 55 is fitted to the upper side of the outer peripheral surface of the connecting rod 13 and integrated with the connecting rod 13 by arc welding, and the lower part is fitted to the lower side of the outer peripheral surface of the connecting rod 13. Side bracket 55b. The upper bracket 55a is formed in an upward U-shaped cross section along a direction orthogonal to the connecting rod 13, and the lower bracket 55b has a U-shaped cross section extending downward along the upper bracket 55a. Is formed. The upper bracket 55a and the lower bracket 55b are abutted against each other at each side of the connecting rod 13, and the abutted portions are respectively connected by bolts 45 and nuts 46, respectively. It is connected.

  A central portion projecting downward in the lower bracket 55b formed in a U-shaped cross-section is configured to be fitted to the upper part of the prismatic battery cell 11, and on the upper surface of the prismatic battery cell 11, When the lower bracket 55b is fitted, the pair of positioning ribs 11m (see FIGS. 51 and 52) for positioning the lower bracket 55b is appropriate in a state along the thickness direction of the rectangular battery cell 11. Each is provided at a certain interval.

  Such a positioning member 55 can be easily attached to an arbitrary position with respect to one connecting rod 13. The upper portions of the prismatic battery cells 11 are fixed by the positioning members 55, respectively.

  53 to 55 show a state in which a pair of restraint plates 12 are restrained by a pair of connecting rods 13 and all corners are formed by a plurality of metal restraint bands 53 each having an end attached to each restraint plate 12. An embodiment in which the battery cell 11 is fixed is shown. Each constraining band 53 is provided with a fitting cylinder portion 53a having a circular cross section that protrudes downward facing the upper surface of the prismatic battery cell 11 along the longitudinal direction. On the upper surface of each square battery cell 11, a short cylindrical fitting protrusion 11k that is fitted into the fitting cylindrical portion 53a of each restraining band 53 is provided. The end of each restraint band 53 is abutted against the restraint plate 12 and attached by welding or the like.

  As described above, all the square battery cells 11 between the respective restraint plates 12 are fixed by the plurality of restraint bands 53, respectively, and the internal pressure of any of the square battery cells 11 is increased to try to expand. Even in this case, the expansion of the prismatic battery cell 11 is suppressed by fixing each prismatic battery cell 11.

  As shown in FIG. 55, the fitting cylindrical portion 53a of each restraining band 53 is abutted against the upper surface of the prismatic battery cell 11 while being fitted to the fitting protrusion 11k of the prismatic battery cell 11. Therefore, a space is formed between the upper surfaces of the adjacent prismatic battery cells 11 and the upper surface of the restraining band 53 between the adjacent fitting cylinder portions 53a, and the cooling air passes through the space. Thus, each square battery cell 11 is efficiently cooled.

  In addition, in order to fix all the square battery cells 11, each restraint band 53 was the structure which provided the fitting cylinder part 53a facing the upper surface of each square battery cell 11, but such a thing. For example, as shown in FIG. 56, the fitting cylinders 53a are arranged at appropriate intervals so as to fix every other square battery cell 11 as shown in FIG. You may make it form the engagement protrusion part 11k only in the square battery cell 11 with which the combined cylinder part 53a is fitted.

  Each constraining band 53 is not limited to such a configuration, and as shown in FIGS. 57 and 58, each constraining band 53 is formed with a pair of long holes 53b at appropriate intervals in the longitudinal direction. Thus, the positioning member 54 that fixes the pair of prismatic battery cells 11 may be attached through the pair of long holes 53b.

  The positioning member 54 has a U-shaped cross section that sandwiches the upper part of a pair of adjacent rectangular battery cells 11 and has a downward U-shape, and protrudes upward from the upper surface thereof into each elongated hole 53b. A pair of bolts 45 to be inserted are fixed. Each bolt 45 is inserted into each of the long holes 53b forming a pair of the restraining bands 53, and the positioning member 54 is fitted to the upper part of the pair of prismatic battery cells 11 by screwing the nuts 46 respectively. The rectangular battery cell 11 is fixed integrally.

  Each positioning member 54 is not limited to the structure attached to the restraining band 53 by the bolt 45 and the nut 46 as described above, but may be attached to the lower surface of the restraining band 53 by spot welding as shown in FIG. Good.

  Furthermore, instead of the upper fixing device for fixing the upper part of the prismatic battery cell 11 as described above, the assembled battery in which the assembled battery 10 is accommodated as shown in FIG. You may make it fix to the bottom face part 21a of the lower case 21 in the case 20. FIG. As shown in FIG. 61, a plurality of support portions 21m are appropriately provided on the bottom surface portion 21a in the longitudinal direction of the bottom surface portion 21a (the stacking direction of the rectangular battery cells 11). The bottom surface portion 21a is formed at a central portion in the width direction with a small interval. In each support portion 21m, the central portion in the thickness direction of the prismatic battery cell 11 is a flat upper surface placed on the prismatic battery cell 11, and each side portion in the longitudinal direction is inclined. ing. A pair of long holes 21n (see FIG. 62) each extending along the longitudinal direction are provided on the upper surface of the support portion 21m.

  As shown in FIG. 62, a positioning member 56 is attached to each support portion 21m. The positioning member 56 has a downward fitting groove portion 56a fitted to the upper portion of the support portion 21m, and a base portion 56b provided so as to protrude upward in the center portion of the fitting groove portion 56a. 63, the fitting groove 56a is supported by the bolt 45 inserted into each long hole 21n provided on the upper surface of the support portion 21m and the nut 46 screwed to each bolt 45. As shown in FIG. It is attached to 21m.

  One prismatic battery cell 11 is placed on the upper surface of the pedestal 56b, and a pair of vertical battery cells 11 are placed on the pedestal 56b along each surface of the prismatic battery cell 11. The engaging pieces 56c are formed by cutting and raising a part of the base portion 56b.

  The lower part of one square battery cell 11 is inserted between the pair of engaging pieces 56c and abuts against the upper surface of the base part 56b. Thereby, the square battery cell 11 is fixed.

  The fixing of the lower part of the rectangular battery cell 11 is not limited to such a lower fixing device. For example, as shown in FIG. 64, a positioning member 57 is attached to each support portion 21m provided in the lower case 21. It may be fixed. A long hole-shaped opening 21p along the longitudinal direction of the prismatic battery cell 11 is provided on the upper surface of the support portion 21m provided in the lower case 21, and the positioning member 57 is provided in the opening 21p. It is installed in the inserted state.

  FIG. 65 is a perspective view showing the positioning member 57, and FIG. 66 is a plan view of the positioning member 57. The positioning member 57 has an engagement tube portion 57a having a long hole cross section inserted into the opening 21p of the support portion 21m. The fitting cylinder part 57a is inserted from the lower side of the lower case 21, and a flange part 57b that abuts against the lower surface of the support part 21m is provided below the positioning member 57. Bolt insertion holes 57c are provided on both sides of the flange portion 57b of the positioning member 57, respectively. The support portion 21m is also provided with a bolt insertion hole to be abutted with each bolt insertion hole 57c, and the flange portion 57b of the positioning member 57 is abutted against the lower surface of the support portion 21m and is inserted into each bolt insertion hole 57c. When each bolt 45 is inserted, a nut 46 is screwed to each bolt 45. Thereby, the positioning member 57 is attached to the support portion 21m.

  As shown in FIG. 67, the lower surface of the prismatic battery cell 11 is provided with an engagement protrusion 11k that protrudes into a short cylindrical shape having a long hole cross section that is fitted into the engagement cylinder 57a of the positioning member 57. The engaging battery 11 is fixed to the bottom surface 21 a by fitting the engaging protrusion 11 k of the prismatic battery cell 11 into the engaging cylinder 57 a of the positioning member 57.

  In the battery pack of another embodiment, the upper pair of connecting rods 13 are used when all the square battery cells 11 are restrained by the pair of restraining plates 12, and the longitudinal length of the assembled battery 10 is appropriate. For example, as shown in FIG. 68, an expansion restraining plate 62 attached to each of the upper pair of connecting rods 13 and the lower case 21 of the assembled battery case 20 may be disposed at the location. The lower sides of the pair of restraining plates 12 are connected to each other by a lower case 21. In the present embodiment, the lower case 21 also functions as a connecting member that connects the pair of restraining plates 12 to each other.

  69 is a front view of the expansion suppression plate 62, FIG. 70 is a bottom view of the expansion suppression plate 62, and FIG. 71 is a side view of the expansion suppression plate 62. The expansion restraining plate 62 has a plate body portion 62a having a rectangular shape similar to the surface of the rectangular battery cell 11, and the plate body portion 62a has a central portion at the upper edge of the plate body portion 62a. On the other hand, a pair of mounting pieces 62b extending substantially perpendicularly in the same direction are provided at an appropriate interval. Each attachment piece 62b is provided with a through hole 62d.

  In addition, a pair of support pieces 62e extending substantially horizontally are provided on the lower side edge of the plate body 62a in the direction opposite to the extending direction of the mounting pieces 62b. Each support piece 62e is also provided with a through hole 62f.

  The plate main body 62a has a width for mutually connecting three vertical slit portions and an intermediate portion in the vertical direction of the vertical slit portions with respect to a region corresponding to one battery case in the rectangular battery cell 11. Slits 62 g each including a directional slit portion are provided at an appropriate interval in the width direction of the rectangular battery cell 11. In other words, the slit 62g has a plurality of groups of an appropriate number, that is, three vertical slit portions in the present embodiment, and the vertical slit portions of each group communicate with each other in the vertical center portion. It is in the state.

  Such an expansion suppression plate 62 is disposed between a pair of prismatic battery cells 11 disposed at an appropriate position in the assembled battery 10, and each mounting piece 62 b is installed between the pair of upper connecting rods 13. It is attached to the connecting plate 63 provided in the above. Each end of the connecting plate 63 is attached to each upper connecting rod 13 by arc welding, and a long hole 63a extending along the connecting rod 13 is provided at a position corresponding to each attaching piece 62b. Yes. Then, the nuts 46 are screwed to the long holes 63a of the connecting plate 63 and the bolts 45 inserted into the through holes 62d of the mounting pieces 62b, so that the mounting pieces 62b of the expansion restraining plate 62 are connected to each other. Each is attached to a plate 63.

  Each support piece 62e provided at the lower portion of the expansion restraining plate 62 is supported on each support portion 21m provided so as to protrude upward from the bottom surface portion 21a of the lower case 21 in the assembled battery case 20. The upper surface of each support portion 21m is flat, and a long hole 21s extending along the axial direction of each connecting rod 13 is provided at the center thereof. Each support piece 62e of the expansion restraining plate 62 is screwed to the bolts 45 respectively inserted into the long holes 21s of the support portion 21m from below the lower case 21, whereby each support portion 21m It is fixed to.

  Thus, the expansion suppression plate 62 fixed at a predetermined position in the assembled battery case 20 is a rectangular battery cell at a predetermined location among the plurality of rectangular battery cells 11 arranged in the assembled battery 10. 11 is fixed to the bottom surface portion 21 a of the lower case 21. In this case, the lower edge portion of the prismatic battery cell 11 placed on each lower support piece 62e is pressed at the lower part of the plate body 62a adjacent to each support piece 62e and is adjacent thereto. The upper edge of the other prismatic battery cell 11 is pressed by the upper part of the plate main body 62a adjacent to each mounting piece 62b. Thus, the square battery cell 11 pressed by the expansion suppression plate 62 presses another adjacent square battery cell 11, thereby suppressing the expansion of each square battery cell 11. Is done.

  Further, the expansion restraining plate 62 is provided with a slit 62g composed of a plurality of vertical slit portions and a width direction slit portion interconnecting the intermediate slit portions, so that an intermediate portion in the vertical direction of the expansion restraining plate 62 is provided. Therefore, even when the prismatic battery cell 11 is expanded, it is easily elastically deformed, and when the expansion stops after the prismatic battery cell 11 expands, it returns to the original flat plate shape. become. In addition, a large number of minute cylindrical projections 11r are provided on the surface of the prismatic battery cell 11. The projections 11r are abutted against the expansion restraining plate 62, so that the expansion restraining plate 62 pushes them. The pressure is reliably transmitted to the prismatic battery cell 11, and the expansion of the prismatic battery cell 11 is reliably prevented.

  In addition, as shown in FIG. 72, the square battery cell 11 may be restrained integrally at an appropriate place by, for example, three sets of metal restraint band bodies 70. Each restraint band body 70 has a pair of first restraint band 71 and second restraint band 72, and one first restraint band 71 is stacked on the upper surface of all restrained prismatic battery cells 11. The other second restraining band 72 is in pressure contact with the bottom surface of all restrained prismatic battery cells 11 along the stacking direction, and each square battery cell 11 located on both sides. It is press-contacted to the surface of this along the up-down direction. And each edge part of the 2nd restraint band 72 is in the state which protruded above each square battery cell 11 located in both sides, and each edge part of the 1st restraint band 71 is in each edge part. They are in a bent state. And as shown in FIG. 73, each end part of the 1st restraint band 71 and each end part of the 2nd restraint band 72 which were faced | matched mutually are respectively couple | bonded by each pair of rivets R, and all restraint The square battery cell 11 is preloaded in the stacking direction. Through holes h through which the bolts 45 are passed are provided at the respective ends of the first restraining band 71 and the second restraining band 72 coupled by the rivets R.

  In this way, an appropriate number of prismatic battery cells 11 are restrained by the plurality of restraint band bodies 70 each having the first restraint band 71 and the second restraint band 72, so that each square battery cell 11 expands. Is suppressed. Then, the square battery cell groups in which the plurality of prismatic battery cells 11 are restrained by the plurality of restraint band bodies 70 are abutted with each other as shown in FIG. The bodies 70 are abutted with each other and are integrally coupled by the bolt 45 and the nut 46. In the present embodiment, a flat plate-like second restraining band 72 that is abutted against the end portions of the plurality of prismatic battery cells 11 arranged in the thickness direction is connected by a flat plate-like first restraining band 71. Therefore, the second restraining band 72 functions as a restraining plate, and the first restraining band 71 functions as a connecting member.

  74 to 78 show an embodiment provided with a connecting rod 73 that functions also as a conduit for guiding the gas discharged from each prismatic battery cell 11, such as hydrogen, to the outside instead of the connecting rod 13. FIG. As shown in FIGS. 74 and 75, in the assembled battery 10 of the present embodiment, in the upper surface of the prismatic battery cell 11 and at a position deviated from the center in the width direction of the prismatic battery cell 11, that is, in the assembled state. A gas discharge cylinder 74 that is discharged when a gas generated from a battery case (not shown), for example, during charging or discharging exceeds a predetermined pressure, is provided immediately below the connecting rod 73. The prismatic battery cells 11 are arranged between the pair of restraining plates 12 so that the gas discharge cylinders 74 are alternately positioned from the center in the width direction of the prismatic battery cells 11. The pair of restraining plates 12 are fastened in a direction to sandwich the square battery cell 11.

  As shown in FIG. 76, the connecting rod 73 has a circular tube shape as a whole, is located in one plane including the axis, is orthogonal to the axis, and extends in the thickness direction of the prismatic battery cell 11. A plurality of connecting cylinders 75 centering on straight lines parallel to each other at an interval of twice the arrangement pitch are provided in communication with each other. The gas discharge cylinder 74 and the connection cylinder 75 are communicated with each other via a connection hose 76 made of, for example, synthetic rubber and fitted at both ends thereof. Thereby, the gas discharged from each square battery cell 11 is guided into the connecting rod 73 and discharged to the outside.

  FIG. 78 shows a structure for discharging the gas guided to the connecting rod 73 to the outside. The ends of the pair of connecting rods 73 are connected to each other by a communication pipe 77, and the communication pipe 77 is connected to a discharge pipe 78 that communicates with the outside through one restraint plate 12. As a result, the gas guided into the connecting rod 73 is discharged to the outside through the communication pipe 77 and the discharge pipe 78. According to the present embodiment, since the connecting rod 73 also serves as a gas pipe that guides the gas discharged from the rectangular battery cell 11, the space in the assembled battery case 20 in which the assembled battery 10 is accommodated is expanded and cooled. Performance is enhanced. Further, since the number of parts is reduced, the mass and cost of the battery pack are reduced.

  FIG. 79 is an assembly view showing a configuration of a battery pack according to another embodiment of the present invention, and FIG. 80 is a cross-sectional view of the battery pack. The assembled battery case 20 of the present embodiment has a basic structure in common with the above-described one, but is slightly different in shape. The prismatic battery cell 11 of this embodiment is basically the same as that described above, but differs in that ears or legs 80 projecting in the width direction are provided at the lower portions of both side surfaces. ing.

  The lower case 21 constituting the lower side of the assembled battery case 20 that houses the assembled battery 10 is pressed from a single metal plate, and includes a horizontal bottom surface portion 21a and both sides of the bottom surface portion 21a. A pair of side surface portions 21b that rise substantially perpendicularly to the portion, a pair of support surface portions that are parallel to the bottom surface portion 21a that extends outward from the upper end of the pair of side surface portions 21b, that is, a flange portion 21c, and a mounting hole The mounting portion 21e is provided so as to be inclined toward the bottom surface portion 21a as it goes outward from the pair of flange portions 21c. The upper case 22 constituting the upper side of the assembled battery case 20 is pressed from a single metal plate material, and has a horizontal upper surface portion 22a and an L-shaped cross section from both sides of the upper surface portion 22a. A pair of side surface portions 22d falling substantially perpendicular to the upper surface portion 22a via the upper side surface portion 22b and the step portion 22c of the mold, and a mounting hole 22e from the lower end of the pair of side surface portions 22d It is comprised from the attaching part 22f which inclined so that it might go to the side which leaves | separates from the upper surface part 22a, so that it goes outside. The lower case 21 and the upper case 22 constituting the lower part and the upper part of the battery module case 20 are formed by pressing from a single metal plate with a fold line parallel to the longitudinal direction of the assembled battery 10 as a boundary. The mounting portions 21e and 22f located at both ends in the width direction are integrally fixed to each other by a fixing screw 23 through the mounting hole 21d and the mounting hole 22e.

  The plurality of prismatic battery cells 11 stacked in the thickness direction between the pair of restraint plates 12 are, for example, a plurality of, for example, six each containing an electrolyte and an electrode for constituting a secondary battery such as a nickel metal hydride battery. A flat box made of resin with a battery case inside, and provided with a pair of connection terminals T consisting of positive and negative terminals at the upper part of the side surface, and its longitudinal direction (width direction), that is, FIG. Are arranged so that the left-right direction is the front-rear direction of the vehicle. Further, the prismatic battery cell 11 includes ears or legs 80 protruding in the width direction (longitudinal direction) from the lower part of the side surface. As described above, a pair of restraining plates 12 that are fastened in a direction approaching each other by two pairs of connecting rods 13 respectively provided above and below the prismatic battery cell 11 in a state where they are overlapped in the thickness direction. So as to be in close contact with each other.

  As shown in detail in FIGS. 80 and 81, a plurality (three in this embodiment) of annular positioning protrusions 81a and a plurality (three in this embodiment) are formed on the overlapping surface, that is, the opposite surface of the prismatic battery cell 11. And three) cylindrical positioning protrusions 81b are arranged in a line along a horizontal straight line passing through the central portion in the height direction. These positioning protrusions 81 a and 81 b are positioned corresponding to the central portion of the battery case in the rectangular battery cell 11. Further, the positioning protrusion 81a and the positioning protrusion 81b are arranged to face each other so as to be fitted to each other when the prismatic battery cell 11 is made adjacent. As shown in FIGS. 82 and 83, the inner diameter of the positioning projection 81a is outside the positioning projection 81b so that the fitting between the positioning projection 81a and the positioning projection 81b in the fitted state is a so-called play fit. A predetermined play (gap) is formed between the inner peripheral surface of the positioning projection 81a and the outer peripheral surface of the positioning projection 81b. This play absorbs the relative movement due to thermal expansion between the prismatic battery cells 11, particularly the relative movement in the width direction of the prismatic battery cell 11, and the connection terminal T constrained by the bus bar 15 is embedded therein. This is to prevent mechanical damage between the prismatic battery cells 11 so as not to damage the connection terminal T.

  As shown in FIG. 84, the connection terminal T has a center portion of the base end surface of the disk-shaped terminal fixing member Ta located between the synthetic resin walls on the side surfaces of the prismatic battery cells 11. They are fixed to the side surfaces of the rectangular battery cells 11 by being fixed to each other by, for example, spot welding, and if excessive mechanical force is applied, the spot welding may be destroyed. Therefore, even if there is a relative movement between the prismatic battery cells 11 due to thermal expansion as described above, the relative movement is limited by the fitting of the positioning protrusion 81a and the positioning protrusion 81b. Inconvenience due to the excessive force applied, for example, between the end surface of the connection terminal T and the side surface of the prismatic battery cell 11 in the connection terminal T portion, and the end surface of the terminal fixing member Ta and the inner wall surface of the prismatic battery cell 11 It is possible to suitably prevent the deterioration or breakage of the sealing performance maintained by the O-ring 79 sandwiched between the two.

  Each rectangular battery cell 11 is in a state where a pair of seating surfaces 82a positioned at both ends in the longitudinal direction of the lower end face 82 of the rectangular battery cell 11 are seated on a pair of horizontal flange portions 21c. When the battery cell 11 is fixed to the lower case 21, a gas inflow path 83 for introducing air for cooling by passing through a slight gap between the battery cells 11 is provided at the lower end surface of each square battery cell 11. 82 and the bottom surface portion 21 a of the lower case 21. A part of the plurality of prismatic battery cells 11 arranged in the thickness direction, for example, every few leg portions 80 in the arrangement direction, is formed on the seating surface by, for example, press-fitting or insert molding, as shown in FIGS. A fixing screw 85 and a stepped screw 86 are screwed through a hole 87 provided in the flange portion 21c to a bottomed cylindrical nut 84 embedded in 82a, thereby being fixed to the lower case 21.

  One of the pair of leg portions 80 of the prismatic battery cell 11 fixed to the lower case 21 is fixed with a fixing screw 85 as shown in FIG. 85, and the other leg portion 80 is shown in FIG. Are fixed by a stepped screw 86. As shown in FIG. 86, the stepped screw 86 includes a cylindrical portion 86c having a diameter larger than that of the male screw portion 86b between the head portion 86a and the male screw portion 86b, and the cylindrical portion 86c contacts the nut 84. It is tightened until it touches. In the tightened state of the stepped screw 86, the head portion 86a is not in close contact with the flange portion 21c of the lower case 21, and the space between the outer peripheral surface of the cylindrical portion 86c and the inner peripheral surface of the hole 87 into which it is fitted. For example, a predetermined gap A of about 1 to 2 mm is formed. This gap A is for absorbing the thermal expansion in order to prevent problems due to the thermal expansion of the prismatic battery cell 11.

  FIG. 87 shows another example of the bus bar 15 that electrically connects the connection terminal T fixed to the upper part of the side surface of the prismatic battery cell 11. The bus bar 15 of the present embodiment is integrally bent from a metal plate material by a press or the like, and is a pair of end portions 15a that are flattened to be tightened by a nut 16, and both end portions thereof. And a U-shaped portion 15b bent in a U-shape between 15a. Since the U-shaped portion 15b is easily elastically deformed, relative deformation between the pair of end portions 15a is relatively easily allowed. For this reason, the deterioration of the sealing performance of the connection terminal T part, the destruction of the connection terminal T, etc. are prevented suitably.

  88 and 90 correspond to the case where a plurality of prismatic battery cells 11 stacked in the thickness direction between a pair of constraining plates 12 have gaps generated by high-temperature creep from the initial pressed state. The configuration is shown. A cylindrical elastic member 88 is attached to a position deviated from the central portion in the width direction of the prismatic battery cell 11 in the upper part of the combination surface of the prismatic battery cell 11. The elastic member 88 has a cylindrical shape, and is fitted on a columnar protrusion 89 shorter than the elastic member 88 protruding from the combination surface, for example, as shown in detail in FIG. Thereby, the elastic member 88 can be compressed by a dimension obtained by subtracting the length (height) dimension of the cylindrical protrusion 89 from the length dimension in the axial direction. Further, the elastic member 88 is provided only at one place so as not to face each other on the combination surface of the adjacent rectangular battery cells 11. When the plurality of prismatic battery cells 11 stacked in the thickness direction are restrained in a pressed state between the pair of restraining plates 12, the elastic member 88 is elastically deformed to the height of the columnar protrusion 89. Even if the prismatic battery cell 11 is plastically deformed by high temperature creep and a gap is generated between the prismatic battery cells 11, the pressed state is maintained by the elastic restoring force of the elastic member 88. 11 rattling is prevented.

  FIG. 91 shows a structure in which the prismatic battery cell 11 is fixed using the leg portions 80 protruding in the width direction from both side surfaces thereof. In this embodiment, a long rail 90 having an inner wall surface shape similar to the outer shape of the leg portion 80 is prepared by extrusion molding or press molding, and is cut in advance to the same length as the assembled battery 10. The legs 80 of the plurality of prismatic battery cells 11 arranged closely in the thickness direction are fixed to the lower case 21 together with the prismatic battery cells 11 by, for example, fixing screws 85 in a state where the legs 80 are fitted inside the rails 90. Has been. According to this embodiment, even when a gap is generated between the prismatic battery cells 11 due to high temperature creep, for example, the upper part of the prismatic battery cell 11 is prevented from shaking in the stacking direction, that is, the vehicle width direction. .

The embodiment shown in FIGS. 92 to 95 is a fixing member for fixing a part of each of the square battery cells 11 stacked in the thickness direction to constitute the assembled battery 10 to the other battery cell 11. Alternatively, it is used as a part of the structural member. That is, a predetermined number of square battery cells 11a positioned at both ends of each of the square battery cells 11 arranged in the thickness direction and a predetermined number of 8 between the pair of square battery cells 11a in this embodiment. Cylindrical nuts 84 and 97 are respectively embedded in the seating surface 82a of the rectangular battery cell 11a and the upper surface 92 of the leg portion 80, and the fixing bolt 85 is provided in the hole 87 of the lower case 21. The rectangular battery cell 11a is fixed to the lower case 21 by being screwed into a nut 84 embedded in the seating surface 82a. Also, as shown in FIG. 93, a longitudinal member press-molded from a metal plate material and having a U-shaped main body 93, an elastic sheet 94 made of synthetic rubber or the like attached to one surface of the main body 93, A retainer 96 having attachment holes 95 formed at a predetermined interval so as to correspond to the positions of the prismatic battery cells 11a in the main body 93 is used. As shown in FIG. 92, the retainer 96 is placed on the upper surface 92 of the leg portion 80, and the fixing bolt 98 is screwed into the nut 97 embedded in the upper surface 92 of the leg portion 80 through the mounting hole 95. 94, it is fixed to the upper surface 92 of the leg portion 80 of the prismatic battery cell 11a. At the same time, as shown in FIG. 95, the upper surface 92 of the leg portion 80 of the prismatic battery cell 11 positioned between the prismatic battery cells 11 a is pressed by the retainer 96 to be fixed to the lower case 21. As shown by the arrow in FIG. 95, the pressing force F applied perpendicularly from the retainer 96 to the upper surface 92 of the leg 80 is equal to the component F _{1 in} the width direction of the rectangular battery cell 11, that is, the vehicle front-rear direction. Since it has a direction component F ₂ toward the lower side of the battery cell 11, that is, toward the lower case 21, vibration and movement of these direction components are suppressed.

  According to the assembled battery 10 of the present embodiment, the number of fastening bolts 85 for fixing the assembled battery 10 is reduced, so that the assembly workability is improved and the assembly cost is reduced. Further, in this embodiment, a pair of restraint plates 12 for clamping the respective square battery cells 11a, 11 arranged in the thickness direction and a connecting rod 13 for connecting them are not necessary. However, such a constraining plate 12 and a connecting rod 13 may be provided in the assembled battery 10 of the present embodiment.

  As mentioned above, although one Example of this invention was described based on drawing, this invention is applied also in another aspect.

  For example, in the above-described embodiment, the square battery cell 11 is fixed to the lower case 21, but may be fixed to the upper case 22.

  The above description is merely an example of the present invention, and the present invention can be modified in various ways without departing from the spirit of the present invention.

10: assembled battery 11: prismatic battery cell 11c: engagement protrusion (positioning protrusion)
11d: Engagement claw part (engagement release prevention device)
11x: Protruding protrusion 11z: Collar 12: Restraining plate 13: Connecting rod (connecting member)
17: Intermediate restraint plate 18: Screw member 20: Battery case 21: Lower case (support member)
21a: bottom part 21b: side part 21c: flange part 21d: mounting part 22: upper case 22a: upper part 22b: upper side part 22c: step part 22d: side part 22e: flange part 24: elastic member 29: connecting bracket 31 : Expansion restraint plate (restraint member)
32: Expansion restraining member (fixing device)
35: Expansion suppression plate, 36: Stepped bolt, 38: Belleville spring (pressing device)
37: Seal member 39: Positioning piece (positioning member)
41: Positioning plate 42: Connection plate 44: Positioning member 47: Support plate 48: Positioning member 51: Connection plate 52: Positioning plate 53: Restraint band 54: Positioning member 55: Positioning member 56: Positioning member 57: Positioning member 62: Expansion restraint plate (restraint member)
62g: slit 63: connecting plate 71: first restraining band (connecting member)
72: Second restraint band (restraint plate)
84: Nut, 85: Fixing bolt (first fixing device)
94: Elastic sheet (pressing member)
96: Retainer (Retainer member)
97: Nut, 98: Fixing bolt (second fixing device)

Claims (20)

A battery pack for a vehicle including an assembled battery in which a plurality of rectangular battery cells having a flat plate shape are stacked in the thickness direction,
The battery pack is provided with a pair of restraint plates that are respectively abutted against the square battery cells located at both ends in the stacking direction, and the square battery cells between the restraint plates are pressed. The pair of restraint plates are connected to each other by a longitudinal connection member disposed on both sides of the square battery cell,
The assembled battery is housed in an assembled battery case,
The assembled battery case includes a lower case and an upper case provided with flange portions projecting in the width direction of the rectangular battery cell on both sides, respectively, and the lower flange portion of the lower case and the upper flange of the upper case Are fixed to each other and joined together,
A vehicle battery pack, wherein a lower flange portion of the lower case is fixed to the vehicle body with a gap formed between the lower case and the vehicle body. Positioning protrusions and positioning recesses for positioning with respect to other rectangular battery cells adjacent to each other in the thickness direction are provided on the mutually facing surfaces of the respective square battery cells, and the positioning protrusions The vehicle battery pack according to claim 1, wherein the positioning recess is fitted to a positioning recess and a positioning protrusion provided in the adjacent square battery. The connecting members are respectively arranged on the upper side and the lower side of the prismatic battery cell, and the fastening allowance to the pair of restraining plates by the connecting member located on the upper side depends on the connecting member located on the lower side. The vehicle battery pack according to claim 1 or 2, wherein the battery pack is larger than a fastening allowance for the pair of restraining plates. The connecting member is disposed on an upper side and a lower side of the prismatic battery cell, and each of the prismatic battery cells has an upper part thicker than a lower part. The battery pack for vehicles as described. The vehicular battery pack according to any one of claims 1 to 4, wherein a central portion of the pair of restraining plates bulges to a side opposite to the square battery cell side. Spaces for circulating cooling gas are provided between the lower case and the lower end surface of the prismatic battery cell and between the upper case and the upper end surface of the prismatic battery cell, respectively. Item 6. The vehicle battery pack according to any one of Items 1 to 5. The lower case includes a bottom portion, a pair of side portions extending from both side edges of the bottom portion to the upper case side, and the lower flange extending outward from the pair of side portions. A lower space for circulating a cooling gas is formed between the bottom surface and the lower end surface of the prismatic battery cell,
The upper case includes an upper surface portion that is smaller than the width of the rectangular battery cell, and a pair of upper side surface portions that press the upper end surface of the rectangular battery cell from both edges of the upper surface portion toward the square battery cell, A pair of step portions respectively extending in directions away from the ends of the pair of upper side surface portions, a pair of side surface portions extending from the ends of the pair of step portions to the lower case side, and the pair of step portions The upper flange portion extending outward from the tip of the side surface portion, and a gap between the square battery cells is interposed between the upper surface portion and the upper end surface of the square battery cell. The vehicle battery pack according to claim 1, further comprising: an upper space communicated with the lower space. The vehicle battery pack according to claim 6 or 7, wherein an elastic member is interposed between the upper case and an upper surface of any one of the rectangular battery cells restrained by the pair of restraining plates. The vehicle battery pack according to claim 8, wherein the elastic member is a hollow body having a long cylindrical shape. The intermediate restraint plate is interposed between the plurality of prismatic battery cells constituting the assembled battery, and the intermediate restraint plate is positioned by the connecting member. The battery pack for vehicles as described. Engagement protrusions are provided on both side surfaces of at least one pair of prismatic battery cells of the plurality of prismatic battery cells stacked in the thickness direction, and the engagement hole portions engage with the engagement protrusions. The vehicle battery pack according to any one of claims 1 to 9, further comprising a longitudinal expansion restraining plate that is provided so that the prismatic battery cells cannot move in the stacking direction. A disengagement prevention device for maintaining an engagement state with the engagement hole portion of the expansion restraining plate is provided at the engagement protrusion portion protruding from both side surfaces of the square battery cell. Item 12. The vehicle battery pack according to Item 11. At least one of the pair of restraining plates is provided with a pressing device that applies a preload to the prismatic battery cells in order to elastically press the plurality of prismatic battery cells stacked in the thickness direction. The vehicle battery pack according to any one of claims 1 to 12. The vehicle battery pack according to any one of claims 6 to 13, wherein any one of the plurality of rectangular battery cells is fixed to a lower case or an upper case of the assembled battery case by a fixing device. . Positioning members for determining the stacking position in the thickness direction are provided at predetermined positions in the respective square battery cells, and are attached to the adjacent square battery cells between the pair of restraining plates. The vehicle battery pack according to any one of claims 1 to 13, wherein the positioning members are pressed against each other. The connecting member is a connecting rod having a rod shape, and each prismatic battery cell is provided with a restraining protrusion through which the connecting rod is inserted. The vehicle battery pack according to any one of claims 1 to 13, wherein a cylindrical metal collar fitted to the rod is provided. The vehicle battery pack according to any one of claims 1 to 16, wherein a positioning member for positioning and fixing any of the rectangular battery cells stacked between the restraint plates is attached to the connecting member. . An expansion suppression plate fixed by any one of the connecting members is disposed between the adjacent rectangular battery cells, and the expansion suppression plate presses one of the adjacent rectangular batteries. The vehicle battery pack according to any one of claims 1 to 17. The vehicle battery pack according to claim 18, wherein the expansion suppression plate is provided with a slit. A first fixing device for fixing a part of the square battery cells including both ends of the square battery cells stacked in the thickness direction to a support member that supports the assembled battery;
A retainer member parallel to the longitudinal direction of the assembled battery;
A second fixing device for fixing the retainer member to the prismatic battery cell fixed to the support member by the first fixing device;
The other prismatic battery cell is interposed between the retainer member and the other prismatic battery cell positioned between the prismatic battery cells to which the retainer member is fixed by the second fixing device. The vehicle battery pack according to claim 1, further comprising: a pressing member that is pressed against and fixed to the battery pack.

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