JP7035847B2 - Power storage device - Google Patents

Description

The present disclosure relates to a power storage device.

Various power storage devices have been conventionally proposed. For example, the power storage device described in JP-A-2017-92030 includes a plurality of unit batteries arranged in one direction and a bus bar for electrically connecting adjacent unit batteries in series. Each bus bar is provided with a connection piece for connecting each bus bar and the voltage detection wiring, and each voltage detection wiring is connected to the voltage detection device. Each voltage detection wiring includes a conductor wiring and an outer cover covering the surface of the conductor wiring.

Japanese Unexamined Patent Publication No. 2017-92030

In the above power storage device, a voltage detection wiring is connected to each bus bar. Generally, the power storage device includes a plurality of power storage cells, and a plurality of bus bars for electrically connecting adjacent power storage cells are also provided.

Therefore, when trying to connect the voltage detection wiring to each bus bar, it becomes necessary to prepare a plurality of voltage detection wirings, which causes an increase in the number of parts.

Therefore, instead of a plurality of voltage detection wirings, it is conceivable to provide a wiring board in which a plurality of wirings are formed in the power storage device and electrically connect each bus bar to the wiring board.

Here, in the power storage device described in Japanese Patent Application Laid-Open No. 2017-92030, even if vibration or the like is applied to the power storage device, the voltage detection wiring is deformed, so that the voltage detection wiring and the connection portion of the connection piece are connected. It is suppressed that a large load is applied.

As described above, when a wiring board is used instead of a plurality of voltage detection wirings, the wiring board is less likely to be deformed than the voltage detection wiring, so that the wiring is performed when vibration is applied to the power storage device. Excessive stress may be applied at the connection site of the board and the connection piece.

The present disclosure has been made in view of the above-mentioned problems, and the purpose of the present disclosure is to reduce the number of parts and to reduce the number of parts, and also to connect pieces and wiring boards even when vibration is applied to the power storage device. It is an object of the present invention to provide a power storage device capable of suppressing a large load from being applied to a connection portion of the above.

The power storage device according to the present disclosure includes a power storage module including a first power storage cell and a second power storage cell arranged in an array direction, a wiring board, a first external terminal provided in the first power storage cell, and a second power storage cell. A second external terminal adjacent to the first external terminal in the arrangement direction, a bus bar for connecting the first external terminal and the second external terminal, and a connection piece for connecting the bus bar and the wiring board are provided. .. The connection piece is connected to the first extension piece extending from the bus bar in the width direction of the power storage module, and is connected to the first extension piece and bent so as to overlap the first extension piece. The second extension piece extending in a direction different from the extension direction and the second extension piece are connected to the second extension piece, and the tip of the second extension piece rises from the tip of the second extension piece to the second extension piece. Includes a third extension piece formed by bending.

According to the above-mentioned power storage device, even if the wiring board or the like vibrates in various directions, an excessive load is applied to the wiring board and the connection portion with the connection piece by appropriately deforming the second extension piece or the like. Can be suppressed.

According to the power storage device according to the present disclosure, the number of parts can be reduced, and even when vibration is applied to the power storage device, a large load is suppressed from being applied to the connection piece and the connection portion of the wiring board. be able to.

It is a top view which shows the electric storage device 1 schematically. It is a perspective view which shows the storage cell 2. It is a perspective view which shows the wiring board 5, a plurality of bus bars 3, and a plurality of connection pieces 7. It is a perspective view which shows the connection piece 7. It is a perspective view in the state which the connection piece 7 is unfolded. It is a perspective view in the state which the metal plate 45 was bent in the bent part 43. It is a perspective view which shows the state which the metal plate 45 was bent in the bent part 44 from the state shown in FIG. It is a perspective view which shows the state which applied the external force to the connection piece 7. It is an exploded perspective view which shows the connection piece 70 and the wiring board 71 which concerns on 1st comparative example. It is a perspective view which shows the connection piece 80. It is a perspective view which shows the connection piece 90.

The power storage device according to the present embodiment will be described with reference to FIGS. 1 to 11. Of the configurations shown in FIGS. 1 to 11, the same or substantially the same configuration is designated by the same reference numerals and duplicated description will be omitted. In the configuration shown in the embodiment, the configuration of the claim may be described together in parentheses for the configuration corresponding to the configuration described in the claim.

FIG. 1 is a plan view schematically showing the power storage device 1.
The power storage device 1 includes a power storage module 9 including a plurality of power storage cells 2 arranged in the arrangement direction D, a plurality of bus bars 3 and 4, wiring boards 5, 6 and a plurality of connection pieces 7, 8.

FIG. 2 is a perspective view showing the storage cell 2. The storage cell 2 includes a housing case 10, a positive electrode external terminal 11, and a negative electrode external terminal 12. An electrode body (not shown) is housed in the storage case 10. The storage case 10 includes main surfaces 13, 14, an upper surface 15, a lower surface 16, and side surfaces 17, 18.

The main surface 13 and the main surface 14 are arranged in the arrangement direction D. The side surface 17 and the side surface 18 are arranged in the width direction W of the storage cell 2.

The positive electrode external terminal 11 and the negative electrode external terminal 12 are provided on the upper surface 15, and the positive electrode external terminal 11 and the negative electrode external terminal 12 are arranged at intervals in the width direction W.

In FIG. 1, the plurality of storage cells 2 are arranged so that the positive electrode external terminals 11 and the negative electrode external terminals 12 are alternately arranged in the arrangement direction D. Specifically, the storage cell (first storage cell) 2A, the storage cell (second storage cell) 2B, and the storage cell 2C are sequentially arranged in the arrangement direction D, and are outside the positive electrode of the storage cell 2A. The terminal (first external terminal) 11 and the negative electrode external terminal (second external terminal) 12 of the storage cell 2B are arranged in the arrangement direction D. Similarly, the positive electrode external terminal 11 of the storage cell 2B and the negative electrode external terminal 12 of the storage cell 2C are also arranged in the arrangement direction D.

The plurality of bus bars 3 and 4 electrically connect a plurality of storage cells 2 arranged in the arrangement direction D in series.

The plurality of bus bars 3 are provided on one side surface side of the power storage module 9, and are arranged at intervals in the arrangement direction D. The bus bar 3 connects the positive electrode external terminal 11 and the negative electrode external terminal 12 adjacent to each other in the arrangement direction D. For example, the bus bar 3A electrically connects the positive electrode external terminal 11 of the storage cell 2A and the negative electrode external terminal 12 of the storage cell 2B.

Similarly, the bus bar 4 is provided on the other side surface side of the power storage module 9, and is arranged at intervals in the arrangement direction D. Each bus bar 4 connects a positive electrode external terminal 11 and a negative electrode external terminal 12 adjacent to each other in the arrangement direction D. For example, the bus bar 4A electrically connects the positive electrode external terminal 11 negative electrode external terminal 12 of the storage cell 2B and the negative electrode external terminal 12 of the storage cell 2C.

The wiring board 5 is provided on one side surface side of the power storage module 9, and is formed so as to extend in the arrangement direction D. The wiring board 5 is arranged above each storage cell 2.

The wiring board 6 is provided on the other side surface side of the power storage module 9, and is formed so as to extend in the arrangement direction D. The wiring board 6 is arranged above each storage cell 2.

A connection piece 7 is connected to each bus bar 3, and each connection piece 7 electrically connects the bus bar 3 and the wiring board 5. A connection piece 8 is connected to each bus bar 4, and each connection piece 8 electrically connects the bus bar 4 and the wiring board 6.

Both the connecting piece 7 and the connecting piece 8 are made of the same metal material as the bus bar 3 and the bus bar 4.

Here, the bus bar 3 is formed in the same manner as the bus bar 4, and the wiring board 5 is formed in the same manner as the wiring board 6. Further, the connection piece 7 is formed in the same manner as the connection piece 8. Therefore, the bus bar 4, the wiring board 6, and the connection piece 8 will be described in detail.

FIG. 3 is a perspective view showing a wiring board 6, a plurality of bus bars 4, and a plurality of connection pieces 7.
The wiring board 6 includes a board 20 and a plurality of voltage lines 21 formed on the upper surface of the board 20. The substrate 20 is formed of an insulating material and is formed in a plate shape. The substrate 20 includes side sides 23 and 24 extending in the arrangement direction D, and the side sides 23 and the side sides 24 are arranged in the width direction W. The side 23 is arranged on the storage cell 2 side.

A plurality of notches 25 are formed on the side side 23 at intervals, and one end of the voltage line 21 is arranged in each notch 25. The other end of each voltage line 21 is connected to a voltage detection device (not shown).

The bus bar 4 is formed of a conductive metal material such as aluminum or copper, and the bus bar 4 is formed in a plate shape.

Each connection piece 8 includes an end portion 30 connected to the bus bar 4 and an end portion 31 located on the wiring board 6 side. Then, on the end portion 31 side, the connection piece 8 is inserted into the cutout portion 25 of the wiring board 6, and is welded to the wiring board 6 by the welding portion 32. As a result, each connection piece 8 is connected to each voltage line 21.

Each connection piece 8 is formed by bending a rectangular metal plate. FIG. 4 is a perspective view showing the connection piece 8, and FIG. 5 is a perspective view showing the connection piece 8 in an unfolded state.

The connection piece 8 includes an extension piece (first extension piece) 40, an extension piece (second extension piece) 41, and an extension piece (third extension piece) 42. The extension piece 40 extends from the bus bar 4 to the side of the power storage module 9 shown in FIG. 1, and specifically, is formed so as to extend from the bus bar 4 in the width direction W. The extension piece 41 is connected to the tip end portion of the extension piece 40, and is bent so as to overlap the extension piece 40 at the bending portion 43. In the example shown in FIG. 4 and the like, the extension piece 41 is bent toward the upper surface side of the extension piece 40. Since the extension piece 41 is bent in this way, the extension piece 41 extends in the arrangement direction D different from the width direction W in which the extension piece 40 extends.

The extension piece 42 is formed at the tip end portion of the extension piece 41, and is bent so as to rise from the end portion of the extension piece 41 at the bending portion 44. In the example shown in FIG. 4 and the like, the extension piece 41 is bent so as to extend upward from the end portion. Then, as shown in FIG. 3, the extension piece 42 of the connection piece 8 is inserted into the notch 25.

The process of forming the connection piece 8 will be described with reference to FIG. 5 and the like. In FIG. 5, the connecting piece 8 is formed by bending a metal plate 45 at a bent portion 43 and a bent portion 44. The metal plate 45 is formed in a rectangular shape, and the metal plate 45 includes long sides 46 and 47 and end sides 48.

The long side 46 and the long side 47 are arranged in the lateral direction L2 of the metal plate 45, and each of the long sides 46 and 47 extends in the longitudinal direction L1 of the metal plate 45.

The bent portion 43 is formed near the center of the metal plate 45 in the longitudinal direction L1. The bent portion 43 is inclined so as to approach the end side 48 from the long side 46 side toward the long side 47 side. The angle θ1 indicates the angle formed by the long side 46 and the bent portion 43, and in the example shown in FIG. 5, the angle θ1 is 45 °.

The bent portion 44 is connected to the tip end portion of the bent portion 43 located on the end side 48 side, and is formed so as to extend in the lateral direction L2.

The angle θ2 indicates an angle formed by the bent portion 44 and the long side 47, and in the example shown in FIG. 5, the angle θ2 is 90 °.

FIG. 6 is a perspective view of the metal plate 45 bent at the bent portion 43. By bending the metal plate 45 at the bent portion 43, an extension piece 40 located between the end portion on the bus bar 4 side and the bent portion 43 is formed, located at the end side 48 from the bent portion 43, and is located in the arrangement direction D. An extension piece 49 extending to is formed.

By bending as described above, the bending ridge line 55 is formed in the bending portion 43. The bending radius of the bent portion 43 is larger than 0 mm and smaller than 2.0 mm.

The side portion 50 and the side portion 51 are formed by bending the long side 46. The side portion 50 is located between the bus bar 4 and the bent ridge line 55, and the side portion 51 is located between the bent ridge line 55 and the end side 48.

By bending the long side 47, the side portion 52 and the side portion 53 are formed. The side portion 52 is located between the end portion on the bus bar 4 side and the bent ridge line 55, and the side portion 53 is located between the bent ridge line 55 and the end side 48. The portion that becomes the bent portion 44 overlaps with the side portion 52.

FIG. 7 is a perspective view showing a state in which the extension piece 49 is bent in the bent portion 44 from the state shown in FIG. The bending radius of the bent portion 44 is, for example, larger than 0 mm and smaller than 2.0 mm.

By bending the extension piece 49 in the bending portion 44, the extension piece 41 located between the bending portion 43 and the bending portion 44 is formed. Further, an extension piece 42 located between the bent portion 44 and the end side 48 is formed. In this way, the connection piece 8 is formed.

At this time, the side portion 51 is also bent at the bent portion 44 to form the side portion 57 and the side portion 58. The side portion 57 is located on the upper surface of the extension piece 40, and the side portion 58 extends upward.

FIG. 8 is a perspective view showing a state in which an external force is applied to the connection piece 8. The external force F1 is an external force that presses the upper end of the extension piece 42 so as to approach the bus bar 4 in the width direction W.

When an external force F1 is applied to the upper end of the extension piece 42, the extension piece 40 bends around the side portion 57 so that the extension piece 42 approaches the bus bar 4 in the width direction W. Specifically, the rigidity of the corners of the side portion 57 and the side portion 58 is high, and the rigidity of the corner portions of the bent portion 44 and the side portion 57 is high, and each corner portion presses the extension piece 40. Then, the extension piece 40 is curved around the side portion 57.

The external force F2 is an external force in the direction opposite to the external force F1 in the width direction W. When an external force F2 is applied to the upper end of the extension piece 42, the extension piece 41 is displaced so as to float. Therefore, in FIG. 3, even if the wiring board 6 vibrates in the width direction W, the extension pieces 40 and 41 are deformed as described above, so that a large load is applied to the welded portion 32, the connection piece 8 and the wiring board 6. Can be suppressed, and cracks or the like can be suppressed from being generated in the welded portion 32 or the like.

In FIG. 8, the external forces F3 and F4 are external forces applied to the upper end of the extension piece 42 in the arrangement direction D. When external forces F3 and F4 are applied to the upper end of the extension piece 42, the extension piece 42 rotates around the bent portion 44. Therefore, in FIG. 3, even if the wiring board 6 vibrates in the arrangement direction D, the connection piece 8 is deformed as described above, so that an excessive load is applied to the welded portion 32, the connection piece 8, and the wiring board 6. It is possible to suppress the occurrence of cracks in the welded portion 32.

In FIG. 8, the external force F5 is an external force applied to the upper end of the extension piece 42 toward the upper side in the height direction H. When an external force F5 is applied to the upper end of the extension piece 42, the extension piece 41 rotates about the bending portion 43 so as to be separated from the extension piece 40, so that the upper end of the extension piece 42 moves upward. ..

The external force F6 is an external force applied to the upper end of the extension piece 42 with the upper end of the extension piece 42 facing downward in the height direction H. When an external force F6 is applied to the upper end of the extension piece 42, the extension piece 40 bends so that the extension piece 42 faces downward.

Therefore, in FIG. 3, even if the wiring board 6 vibrates in the height direction H, the welded portion 32, the connection piece 8, and the wiring board 6 are cracked or the like due to the deformation of the connection piece 8 as described above. It can be suppressed from occurring.

Although the configuration of the connection piece 8 has been described in detail, the connection piece 7 is also configured in the same manner, and even if the wiring board 5 vibrates in the arrangement direction D, the width direction W, and the vertical direction, the connection piece 7 and the wiring It is possible to prevent an excessive load from being applied to the connection portion of the substrate 5. FIG. 9 is an exploded perspective view showing the connection piece 70 and the wiring board 71 according to the first comparative example. The connection piece 70 includes a plate-shaped extension piece 75 extending in the width direction W from the bus bar 3 and a plate-shaped extension piece 76 extending upward from the tip end portion of the extension piece 75. The extension piece 76 is bent from the extension piece 75 at the bending portion 77.

Since the bent portion 77 extends in the arrangement direction D, the extension piece 76 is rotatable around the bending portion 77, and the upper end of the extension piece 76 is movable in the width direction W.

On the other hand, if the upper end of the extension piece 76 is to be moved in the arrangement direction D, the extension piece 75 will be deformed so as to be twisted, and the upper end of the extension piece 76 is difficult to move in the arrangement direction D. It has become.

The wiring board 71 includes a board 72 and a voltage line 73 formed on the upper surface of the board 72. An insertion hole 74 is formed on the side side of the substrate 72, and one end of the voltage line 73 is located at the opening edge of the insertion hole 74. The extension piece 76 is inserted into the insertion hole 74, and one end of the voltage line 73 and the extension piece 76 are connected by a welded portion.

In the power storage device configured as described above, the wiring board 71 may vibrate in the arrangement direction D. At this time, since the upper end of the extension piece 76 of the connection piece 70 is difficult to move in the arrangement direction D, a large load may be generated on the connection portion between the extension piece 76 and the wiring board 71.

On the other hand, in the power storage device 1 according to the present embodiment, even if the wiring boards 5 and 6 vibrate in various directions, a large load is applied to the connection portions between the connection pieces 7 and 8 and the wiring boards 5 and 6. It can be suppressed from being added.

In FIG. 3, the connection piece 7 can be inserted through the opening on the side 23 side of the notch 25. Therefore, the connection piece 7 can be inserted into the notch 25 without accurately forming the depth of the notch 25 in the width direction W.

On the other hand, in the example shown in FIG. 9, when the length of the insertion hole 74 in the arrangement direction D is smaller than the width of the extension piece 76 in the arrangement direction D, the extension piece 76 cannot be inserted. .. Therefore, the dimensional accuracy required for the extension piece 76 is higher than the dimensional accuracy required for the notch 25, and as a result, the manufacturing cost of the wiring board 71 is high. In other words, in the power storage device 1 according to the present embodiment, the manufacturing cost can be reduced.
(Example)
Table 1 below shows whether or not cracks occur in the welded parts of the connection piece and the wiring board when vibration is applied to the wiring board with various connection pieces prepared and each connection piece welded to the wiring board. The result of observing the wiring is shown.

Specifically, the "conventional method" shows the result when the connection piece 70 shown in FIG. 9 is used. "Study 1" shows the result when the connection piece 8 shown in FIG. 4 or the like is used. "Examination 2" shows the result when the connection piece 80 shown in FIG. 10 is used. "Examination 3" shows the result when the connection piece 90 shown in FIG. 11 is used.

FIG. 10 is a perspective view showing the connection piece 80. The connection piece 80 includes an extension piece 81 extending in the width direction W and an extension piece 82 extending upward. The extension piece 82 is formed by bending the extension piece 83 upward from the tip end portion of the extension piece 81 at the bending portion 83.

FIG. 11 is a perspective view showing the connection piece 90. The connecting piece 90 includes an extension piece 91 extending in the width direction W and an extension piece 92 extending upward from the vicinity of the tip of the extension piece 91.

The connection piece 90 has the same shape as the connection piece 80, but the connection piece 90 is not formed by bending the extension piece 92 with respect to the extension piece 91, but has an L-shape. It is formed by processing a part of the metal member of.

Table 1 above shows the results of the following test conditions in which 50 connection pieces 70, 8, 80, and 90 formed as described above were prepared, and each connection piece was connected to the wiring board. There is.

The test conditions include a vibration cycle, a vibration direction, and a vibration acceleration.
The vibration cycle is 15 minutes, during which the vibration cycle is increased from 7 Hz to 200 Hz and further decreased from 200 Hz to 7 Hz.

The vibration directions are the vertical direction (height direction H), the left-right direction (width direction W), and the front-back direction (arrangement direction D). Then, the vibration cycle of the above 15 minutes is repeated 12 times in the vertical direction (height direction H) for 3 hours. The above 15-minute vibration cycle is repeated 12 times in the left-right direction (arrangement direction D) for 3 hours. The above 15-minute vibration cycle is repeated 12 times in the front-back direction (width direction W) for 3 hours. The vibration acceleration is 8G.

As shown in Table 1, in the samples using the connection pieces 70, 80, 90 (“conventional method”, “examination 2”, “examination 3”), cracks occur in the welded portion in any of the vibration directions. did.

On the other hand, in the 50 samples (Study 1) in which the connection piece 8 and the wiring board were connected, it was found that no cracks were generated in the welded portion between the connection piece 8 and the wiring board.

It should be considered that the embodiments disclosed this time are exemplary in all respects and not restrictive. The scope of the present invention is indicated by the scope of claims and is intended to include all modifications within the meaning and scope equivalent to the scope of claims.

1 power storage device, 2 power storage cell, 3,4 bus bar, 5,6,71 wiring board, 7,8,70,80,90 connection piece, 9 power storage module, 10 storage case, 11 positive electrode external terminal, 12 negative electrode external terminal , 13, 14 main surface, 15 upper surface, 16 lower surface, 17, 18 side surface, 20, 72 substrate, 21,73 voltage line, 23, 24 side side, 25 notch, 30, 31 end, 32 weld, 40 , 41,42,49,75,76,81,82,91,92 Extension piece, 43,44,77,83 Bent part, 45 metal plate, 46,47 long side, 48 end side, 50,51, 52, 53, 57, 58 Sides, 55 ridges, 74 insertion holes, D arrangement direction, F1, F2, F3, F4, F5, F6 external force, H height direction, L1 longitudinal direction, L2 lateral direction, W width direction.

Claims (1)

A storage module including a first storage cell and a second storage cell arranged in the arrangement direction,
Wiring board and
The first external terminal provided in the first storage cell and
A second external terminal provided in the second storage cell and adjacent to the first external terminal in the arrangement direction,
A bus bar connecting the first external terminal and the second external terminal,
A connection piece connecting the bus bar and the wiring board,
Equipped with
The connection piece is
A first extension piece extending from the bus bar in the width direction of the power storage module,
In addition to being connected to the first extension piece , the first extension piece is bent with respect to the first extension piece at a bent portion extending diagonally with respect to the extending direction, and the first extension piece is formed. A second extension piece that is bent so as to overlap with the first extension piece and extends in a direction different from the extension direction of the first extension piece.
Includes a third extension piece that is connected to the second extension piece and is formed by bending from the tip of the second extension piece so as to stand up against the second extension piece.
A power storage device in which the length of the connection piece from the connection portion of the connection piece and the bus bar to the end edge of the connection piece is longer than the length of the bus bar in the arrangement direction.

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