JP2008147046A - Battery pack and manufacturing method of battery pack - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a battery pack capable of simplifying assembly and a manufacturing method of the battery pack. <P>SOLUTION: The battery pack comprises a plurality of battery modules 20, a bundling part 29 as an engaging projection part 22 which protrudes in a direction Y crossing at right angles the lamination direction X laminating a plurality of batteries from the side face 21 of the battery module, a pair of wall members 41 which are arranged facing each other to the side face of the battery module and extend along the lamination direction, an engaging recessed part 42 which is provided on a pair of wall members and in which a bundling part of the battery module is inserted, and a fixing member 60 which fixes the bundling part inserted in the engaging recessed part. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an assembled battery and a method for manufacturing the assembled battery.

  Generally, a battery pack having a high output and a high capacity is obtained by arranging a plurality of battery modules and electrically connecting each battery module in series and / or in parallel. The output terminals of the battery modules are electrically connected to each other via a bolted bus bar outside the battery module. The battery module is a unit unit for assembling an assembled battery, and a plurality of electrically connected single cells are housed in a case. The battery module is a type of assembled battery in that it includes a plurality of electrically connected single cells. In the present specification, the battery module is a unit unit for assembling an “assembled battery”. A unit that is housed in a case is referred to as a “battery module”.

When stacking a plurality of battery modules, the battery modules are fastened to each other by inserting relatively long through bolts.
JP 2001-229896 A

  In a configuration in which a plurality of battery modules are stacked using through bolts, a sleeve is assembled in the battery module so that the battery modules are not buckled by the axial force of the through bolt, or adjacent to each other in the stacking direction. There is a problem in that assembly of the assembled battery becomes complicated because a collar for ensuring a cooling air flow path must be inserted between the matching battery modules and inserted into the bolt.

  The objective of this invention is providing the assembled battery which can aim at simplification of an assembly, and the manufacturing method of an assembled battery.

In order to achieve the above object, the invention described in claim 1 includes a plurality of battery modules,
Engaging protrusions projecting in a direction perpendicular to the stacking direction in which the plurality of battery modules are stacked from the facing end surfaces of the battery modules;
A pair of wall members disposed facing each of the end faces of the battery module and extending along the stacking direction;
An engagement recess provided in the pair of wall members and into which the engagement protrusion of the battery module is fitted;
And a fixing member for fixing the engaging convex portion fitted in the engaging concave portion.

The invention according to claim 10 for achieving the above object includes a step of forming a tightening portion by winding the peripheral portions of the plurality of case bodies of the respective battery modules to each other;
Fitting the winding portions of the respective battery modules into engagement recesses provided in a pair of wall members;
The stator is moved along the stacking direction in which the plurality of battery modules are stacked, and the respective winding tightening portions are sandwiched between the engaging recesses to determine the positions along the stacking direction of the plurality of battery modules. And a process for producing an assembled battery.

  In the assembled battery of the present invention, the engaging projections of the battery module are inserted into the engaging recesses provided on the wall member and stacked, and a through-bolt inserted through a plurality of battery modules is not required. . Further, in the method for manufacturing an assembled battery according to the present invention, the tightening portion of the battery module is inserted into the engaging recess provided in the wall member and stacked, and a through bolt inserted into the plurality of battery modules. Do not need. For this reason, it is not necessary to assemble the sleeve for receiving the axial force of the through bolt into the battery module. Further, there is no need to arrange a collar for securing the cooling air flow path between the battery modules adjacent in the stacking direction. Therefore, compared with the form which laminates | stacks several battery modules using a through bolt, the simplification of manufacture of a battery module or an assembly of an assembled battery can be achieved.

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 1A is a perspective view showing a state in which an assembled battery 11 according to an embodiment of the present invention is viewed from the front side, and FIG. 1B is a perspective view showing a state in which the assembled battery 11 is viewed from the back side. 2A, 2B, and 2C are a plan view, a front view, and a rear view showing the assembled battery 11, respectively. FIGS. 3A and 3B are a front view and a left side view showing an example of the battery module 20 which is a unit unit when assembling the assembled battery 11, and FIG. 4C is a schematic cross-sectional view taken along the line 3C-3C, FIG. 4A is a diagram for explaining the tightening portion 29 as the engagement convex portion 22 in the battery module 20, and FIG. 4B is FIG. It is sectional drawing which follows the 4B-4B line. FIG. 5 is a perspective view showing an example of the flat battery 28. FIGS. 6A, 6 </ b> B, and 6 </ b> C are views for explaining the operation of the fixing member 60 that fixes the winding fastening portion 29 as the engaging convex portion 22 fitted in the engaging concave portion 42. 1A and 6A, the axis X indicates the stacking direction in which the plurality of battery modules 20 are stacked, and the axis Y indicates the direction orthogonal to the stacking direction.

  In summary, the assembled battery 11 of the present embodiment protrudes from a plurality of battery modules 20 and end faces 21 facing each other in the battery module 20 in a direction Y perpendicular to the stacking direction X in which the plurality of battery modules 20 are stacked. A pair of wall members 41 that are arranged to face the engaging protrusions 22 and the end surfaces 21 of the battery module 20 and extend along the stacking direction X, and provided on the pair of wall members 41, It has the engaging recessed part 42 in which the convex part 22 fits, and the fixing member 60 which fixes the engaging convex part 22 fitted in the engaging recessed part 42. Details will be described below.

  With reference to FIG. 1 and FIG. 2, the assembled battery 11 is an in-vehicle battery mounted on a vehicle such as an automobile or a train, and a plurality of battery modules 20 are stacked with a space therebetween. By connecting any number of battery modules 20 in series and parallel, the assembled battery 11 can handle a desired current, voltage, and capacity. The illustrated assembled battery 11 includes eight battery modules 20, and two battery module groups 20a stacked in the vertical direction in FIG. 1 are arranged in four rows in the horizontal direction. The positive and negative output terminals 23 and 24 are provided on the front surface of the battery module 20.

  The battery module 20 is air-cooled, and a space 43 is formed between the battery modules 20 adjacent in the stacking direction X. The space 43 is used as a cooling air flow path through which cooling air for cooling each of the battery modules 20 flows. By cooling each battery module 20 by flowing cooling air, the battery temperature is lowered and the deterioration of characteristics such as charging efficiency is suppressed.

  3 and 4, the battery module 20 forms a unit unit for assembling the assembled battery 11, and a plurality of (for example, eight) flat batteries 28 connected in series are accommodated in the module case 25. ing. The plurality of flat batteries 28 are stacked in the thickness direction (vertical direction in FIG. 4B) and connected in series.

  The module case 25 has a plurality of case bodies, that is, a first case 26 that has a box shape with an opening formed therein, and a second case 27 that forms a lid that closes the opening. The first case 26 and the second case 27 are formed from a relatively thin steel plate or aluminum plate, and are given a predetermined shape by press working. A winding-up portion 29 is formed by winding up the peripheral portions 26a, 27a of the first and second cases 26, 27 to each other. As shown in FIG. 3C and FIG. 4B, the winding portion 29 is formed from the facing side surface 21 (corresponding to the facing end surface) of the battery module 20 in the stacking direction X ( It protrudes in a direction Y (left and right direction in the figure) orthogonal to the up and down direction in the figure. In the present embodiment, the engaging convex portion 22 is composed of a tightening portion 29.

  The positive and negative output terminals 23 and 24 are led out from the module case 25 through a notch formed in a part of the first case 26.

  Referring to FIG. 5, the flat battery 28 (hereinafter, also simply referred to as “battery”) is, for example, a flat lithium ion secondary battery, and is a stacked type in which a positive electrode plate, a negative electrode plate, and a separator are sequentially stacked. A power generation element (not shown) is sealed with an exterior material 28a such as a laminate film. In the battery 28, one end is electrically connected to the power generation element, and a plate-like electrode 28t (a general term for the positive electrode 28p and the negative electrode 28m) is led out from the exterior member 28a. The electrode 28t extends on both sides of the battery 28 in the longitudinal direction. In the battery 28 including the stacked power generation element, it is necessary to apply pressure to the power generation element and hold it in order to maintain the distance between the electrode plates and maintain the battery performance. For this reason, each battery 28 is accommodated in the module case 25 so that the power generation element is pressed down. The electrode 28t is sandwiched between the holding plates 30 from both sides along the stacking direction X of the batteries 28 (see FIG. 4B). The holding plate 30 is made of an electrically insulating material, for example, an electrically insulating resin material.

  As shown in FIGS. 1 (A) and 2 (B), the pair of wall members 41 are arranged to face each of the side surfaces 21 of the battery module 20 and are arranged in the stacking direction X (vertical direction in the figure). It stretches along.

  The pair of wall members 41 are formed with engaging concave portions 42 into which the engaging convex portions 22 of the battery module 20, that is, the winding fastening portions 29 of the module case 25 are fitted. Since two battery modules 20 are stacked in the up-down direction, two engaging recesses 42 are formed in one wall member 41 apart in the stacking direction X (up-down direction). The engaging recesses 42 that are adjacent along the stacking direction X are formed at positions where the space portions 43 are formed between the battery modules 20 that are adjacent along the stacking direction X (see FIG. 2B).

  The pair of wall members 41 includes a pair of wall surfaces 45 facing each other in a storage box 44 that stores a plurality of battery modules 20. The storage box 44 has a box shape in which a pair of wall surfaces 45 is combined with a lower plate 46 and a top plate 47. Since this assembled battery 11 has four battery module groups 20a, four pairs of wall members 41 are required. In the illustrated example, each battery module group 20a is stored in a storage container 49 in which four storage boxes 44 are provided, that is, four storage boxes 44 are connected. Adjacent battery module groups 20 a share a wall surface 45 that partitions adjacent storage chambers 48 as one wall member 41.

  The storage box 44 is provided on the outer surface of the rear wall 50, an opening 44 a that is opened to store a plurality of battery modules 20 (upper and lower two in the illustrated example), a back wall 50 that faces the opening 44 a, and And a holding member 52 that holds a bus bar 51 that electrically connects the battery modules 20 to each other.

  The eight battery modules 20 are connected in series via a bus bar 51 extending in the horizontal direction or the vertical direction. In the battery module group 20a shown on the leftmost side in FIG. 1B, a bus bar 53 is connected to the positive output terminal 23 of the upper battery module 20, and a bus bar 53 is connected to the negative output terminal 24 of the lower battery module 20. 54 is connected. The bus bar 53 forms a positive output terminal of the assembled battery 11, and the bus bar 54 forms a negative output terminal of the assembled battery 11. The bus bars 51, 53, 54 are screwed to the output terminals 23, 24 of the battery module 20 with bolts. The bus bar 51 and the back wall 50 are formed with through holes for inserting bolts. The holding member 52 is formed of a claw member that is locked to the bus bars 51, 53, and 54. The holding member 52 can be modified to an appropriate configuration as long as it can be held on the back wall 50 so that the bus bars 51, 53, 54 do not fall off, and may be formed, for example, from a groove into which the bus bars 51, 53, 54 are fitted. . The storage box 44 can be formed from a steel plate or an aluminum plate. However, with respect to the back wall 50, an insulating plate is provided from a resin material or the like at a portion where the output terminals 23 and 24 of the battery module 20 abut, or the back wall 50 itself is formed from an insulating material.

  The engaging recess 42 is formed from a long groove that extends from the end of the opening 44a toward the back wall 50 and into which the winding fastening portion 29 is slidably fitted. Accordingly, the plurality of battery modules 20 can be easily stored in the storage box 44 by inserting the battery module 20 from the end of the opening 44 a while fitting the winding portion 29 into the engagement recess 42.

  The back wall 50 is formed with a hole 55 through which cooling air passes. Thereby, the flow of the cooling air in the storage box 44 can be secured. The cooling air flowing into the storage box 44 through the hole 55 cools the battery module 20 and then flows out from the opening 44a. The flow of the cooling air may flow from the opening 44 a and flow out from the hole 55.

  Referring to FIG. 6, the fixing member 60 is attached to the engaging recess 42 so as to be movable along the stacking direction X, and the winding members 29 are sandwiched between the fixing recesses 42. A stator 61 that determines a position along the stacking direction X; and a moving member 62 that moves the stator 61 in a direction in which the tightening portion 29 is sandwiched between the engaging recesses 42. The moving member 62 includes a bolt 63 that moves the stator 61 in accordance with the fastening operation to the stator 61.

  The stator 61 is incorporated into the wall member 41 so as to be movable along the stacking direction X (vertical direction in the figure), and a recess 64 into which the winding fastening portion 29 is fitted is formed. The recess 64 has substantially the same shape as the engagement recess 42. In the initial position of the stator 61 shown in FIG. 6 (A), the concave portion 64 is located at a position continuous with the engaging concave portion 42, and the battery module 20 is obstructed while the winding portion 29 is fitted into the engaging concave portion 42. You can insert without. An approximately chevron-shaped locking piece 65 is provided on the front surface of the recess 64 on the storage chamber 48 side. The locking piece 65 can be inserted into the winding portion 29 from below along the side surface 21 of the battery module 20. A bolt 63 is connected to the upper end of the stator 61. When the bolt 63 is screwed into the stator 61, the stator 61 moves up with the fastening operation. That is, the stator 61 moves in a direction in which the winding portion 29 is sandwiched between the stator 61 and the engaging recess 42. In the fixing position of the stator 61 shown in FIG. 6B, the tightening portion 29 is sandwiched between the upper surface of the engaging recess 42 and the lower surface of the recess 64 of the stator 61. Thus, the stator 61 sandwiches the winding fastening portion 29 between the engaging recess 42 and the position along the stacking direction X of the winding fastening portion 29 is determined. As a result, the stacking direction X of the battery module 20 is determined. The position along is determined.

  Next, the operation will be described.

  When the assembled battery 11 is assembled, each battery module 20 is inserted into the storage box 44 from the opening 44a. At this time, the winding portion 29 of the battery module 20 is fitted into the engaging recess 42 of the wall member 41 from the end of the opening 44a. The battery module 20 is slid while the winding portion 29 is guided by the engaging recess 42.

  When the insertion of each battery module 20 is completed, the bolt 63 is screwed into the stator 61. With this fastening operation, the stator 61 moves upward, the winding fastening portion 29 is sandwiched between the engaging recess 42 and the stator 61, and the position along the stacking direction X of the battery modules 20 is determined (FIG. 6 ( B)). Further, the battery module 20 is prevented from coming off.

  And if the bus bars 51, 53, 54 held on the back wall 50 are screwed to the output terminals 23, 24 of the battery module 20 with bolts, the assembly of the assembled battery 11 is completed.

  As described above, in the assembled battery 11 and the manufacturing method thereof according to the present embodiment, the engagement convex portion 22 of the battery module 20 is fitted into the engagement concave portion 42 provided in the wall member 41 and stacked. Thus, a through bolt for inserting the plurality of battery modules 20 is not required. For this reason, it is not necessary to assemble the sleeve for receiving the axial force of the through bolt into the battery module 20. Further, it is not necessary to arrange a collar for securing the cooling air flow path between the battery modules 20 adjacent to each other along the stacking direction X. Therefore, the manufacturing of the battery module 20 and the assembling of the assembled battery 11 can be simplified as compared with a mode in which a plurality of battery modules 20 are stacked using through bolts. Moreover, since the wall member 41 exists in the side surface 21 of the battery module 20, the cooling air is rectified and the cooling effect of the battery module 20 can be enhanced. Furthermore, although the through bolt is relatively long and the twist of the bolt is relatively large, it is difficult to manage the torque. However, since the assembled battery 11 does not require the through bolt, there is no difficulty in torque management.

  Since the winding fastening part 29 of the module case 25 is used as the engaging convex part 22, it is not necessary to provide the dedicated engaging convex part 22, and the manufacturing of the battery module 20 is not complicated.

  The engaging recesses 42 adjacent along the stacking direction X are formed at positions where the space portions 43 are formed between the battery modules 20 adjacent along the stacking direction X. By simply setting the distance, the size of the space portion 43 can be easily set to a desired size.

  In the embodiment in which a plurality of battery modules 20 are stacked using through bolts, the stacked battery modules 20 are fixed to the lower case using a restraining plate and through bolts, and the upper case is covered, and the upper case is covered with the lower case. Must be fixed to. On the other hand, in this embodiment, since the pair of wall members 41 is composed of a pair of wall surfaces 45 facing each other in the storage box 44, the top plate 47 portion of the storage box 44 has the function of the restraint plate and the upper case. Because of its function, it is possible to reduce the number of parts and the weight. Further, the torsional rigidity of the assembled battery 11 is also improved.

  The bus bars 51, 53, 54 can be held in advance on the rear wall 50 of the storage box 44, and the fastening operation of the bus bars 51, 53, 54 after storing the battery module 20 from the opening 44 a can be performed easily and quickly. Can do.

  The engaging recess 42 is formed from a long groove that extends from the end of the opening 44a toward the back wall 50 and into which the engaging protrusion 22 is slidably fitted. Therefore, the plurality of battery modules 20 are opened. It can be easily stored in the storage box 44 from the end of the portion 44a.

  Since the hole 55 for allowing the cooling air to pass through is formed in the back wall 50, the flow of the cooling air in the storage box 44 can be secured.

  The fixing member 60 includes a stator 61 that sandwiches the engaging convex portion 22 with the engaging concave portion 42, and a moving member 62 that moves the stator 61. The stator 61 is connected to the engaging concave portion 42. By sandwiching the engagement convex portion 22 therebetween, the position along the stacking direction X of the battery modules 20 can be easily determined.

  Since the moving member 62 is composed of the bolt 63 that moves the stator 61 in accordance with the fastening operation to the stator 61, the configuration of the moving member 62 is simplified. Moreover, since this bolt 63 can use a comparatively short thing, the difficulty of torque management does not arise, but fixed quality can be obtained.

  FIGS. 7A and 7B are a plan view and a front view showing a charging device 70 used in the process of charging the battery module 20 into the storage box 44.

  The charging device 70 is arranged on the downstream side of the winding device 71 that winds the module case 25. The charging device 70 includes a loading unit 72 for loading the battery module 20 in which the winding portion 29 is formed, a loading unit 73 for sequentially loading the battery module 20 into the storage box 44, and a storage box before the battery module 20 is loaded. 44, and a second storage portion 75 for storing the storage box 44 after the battery module 20 is inserted. A lifter 76 that allows the storage box 44 to move up and down and feed is disposed in the insertion portion 73. When the battery module 20 is stored on the lower side of the storage box 44, the lifter 76 is lowered and the battery module 20 is stored on the upper side of the storage box 44. In the case of the storage container 49 in which the four storage boxes 44 are connected, the storage container 49 is sent so that the empty storage box 44 is positioned in the input unit 73. The storage container 49 in which the insertion of the battery module 20 is completed is sent to the second storage unit 75.

  Thus, by directly putting the manufactured battery module 20 into the storage box 44, an intermediate case for temporarily storing the manufactured battery module 20 becomes unnecessary. When the intermediate case is used, man-hours for taking in and out of the intermediate case are generated, but such man-hours are not generated, which is advantageous in terms of cost.

FIG. 1A is a perspective view showing a state in which the assembled battery according to the embodiment of the present invention is viewed from the front side, and FIG. 1B is a perspective view showing a state in which the assembled battery is viewed from the back side. . 2A, 2B, and 2C are a plan view, a front view, and a rear view, respectively, showing the assembled battery. 3A and 3B are a front view and a left side view, respectively, showing an example of a battery module that is a unit unit when assembling the assembled battery, and FIG. 3C is a view of 3C in FIG. It is a schematic sectional drawing which follows the -3C line. FIG. 4A is a diagram for explaining a tightening portion as an engaging convex portion in the battery module, and FIG. 4B is a cross-sectional view taken along line 4B-4B in FIG. 4A. It is a perspective view which shows an example of a flat type battery. 6A, 6B, and 6C are diagrams for explaining the operation of the fixing member that fixes the tightening portion as the engaging convex portion fitted in the engaging concave portion. 7A and 7B are a plan view and a front view showing a charging device used in the process of charging the battery module into the storage box.

Explanation of symbols

11 battery pack,
20 battery module,
21 side surfaces (facing end surfaces in the battery module),
22 engaging convex part,
23, 24 output terminals,
25 module case,
26, 27 First and second cases (multiple case bodies),
26a, 27a peripheral edge,
28 flat battery,
29 Tightening part (engagement convex part),
41 wall members,
42 engaging recess,
43 Space,
44 storage box,
44a opening,
45 facing walls in the storage box,
46 Lower plate,
47 Top plate,
48 storage room,
49 storage container,
50 back wall,
51 Busbar,
52 holding members,
53, 54 Bus bar,
55 holes,
60 fixing member,
61 Stator,
62 moving members,
63 bolt (moving member),
64 recesses,
65 locking pieces,
70 dosing device,
71 Tightening device,
72 carry-in part,
73 Input section,
74 first storage section,
75 Second storage section,
76 Lifter,
Axis X Lamination direction in which a plurality of battery modules are laminated,
Axis Y A direction perpendicular to the stacking direction.

Claims (10)

A plurality of battery modules;
Engaging protrusions projecting in a direction perpendicular to the stacking direction in which the plurality of battery modules are stacked from the facing end surfaces of the battery modules;
A pair of wall members disposed facing each of the end faces of the battery module and extending along the stacking direction;
An engagement recess provided in the pair of wall members and into which the engagement protrusion of the battery module is fitted;
And a fixing member for fixing the engaging convex portion fitted in the engaging concave portion. The battery module has a module case in which a winding portion is formed by winding the peripheral portions of a plurality of case bodies to each other,
The assembled battery according to claim 1, wherein the engagement convex portion is configured by the tightening portion.   2. The engagement concave portion adjacent along the stacking direction is formed at a position where a space portion is formed between the battery modules adjacent along the stacking direction. Assembled battery.   2. The assembled battery according to claim 1, wherein the pair of wall members are configured by opposing wall surfaces in a storage box that stores the plurality of battery modules. The storage box has an opening opened to store the plurality of battery modules;
A back wall facing the opening;
The assembled battery according to claim 4, further comprising: a holding member that is provided on the back wall and holds a bus bar that electrically connects the battery modules.   The said engaging recessed part is formed from the long groove which the said engaging convex part fits slidably while extending toward the said back wall from the edge part of the said opening part. Battery pack.   The assembled battery according to claim 5, wherein the back wall is formed with a hole through which cooling air passes. The fixing member is attached to the engagement recess so as to be movable along the stacking direction, and the engagement protrusion is sandwiched between the fixing recess and the position along the stacking direction of the plurality of battery modules. A stator that defines
The assembled battery according to claim 1, further comprising: a moving member that moves the stator in a direction in which the engaging convex portion is interposed between the engaging concave portion and the engaging concave portion.   The assembled battery according to claim 8, wherein the moving member includes a bolt that moves the stator in accordance with a fastening operation to the stator. Forming a tightening portion by winding the peripheral portions of the plurality of case bodies of the respective battery modules to each other; and
Fitting the winding portions of the respective battery modules into engagement recesses provided in a pair of wall members;
The stator is moved along the stacking direction in which the plurality of battery modules are stacked, and the respective winding tightening portions are sandwiched between the engaging recesses to determine the positions along the stacking direction of the plurality of battery modules. And a method of manufacturing the assembled battery.

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