JP2015005384A - Battery pack - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a battery pack capable of improving collision safety without deforming a cell case against impacts from multiple directions. A housing 11 having a hollow structure, which has a plurality of cells 13 therein, does not allow deformation in the axial direction, and allows deformation within a predetermined range in one direction perpendicular to the axial direction, and a housing. A plurality of modules 10 each having an elastic film 12 that is provided at the open end of the body 11 and that deforms following the deformation of the housing are provided, and the adjacent modules 10 have different rigidity directions from each other. By being spread in the axial direction and the one direction, it is possible to provide a battery pack that can improve collision safety without deforming the cell case against impacts from multiple directions. [Selection diagram] Fig. 3

Description

  The present invention relates to a battery pack.

  In-vehicle lithium ion battery packs, there is a risk that the built-in cell case is deformed in the event of a vehicle collision. The cell of the lithium ion battery pack contains an organic electrolyte. If the organic electrolyte leaks from the inside of the cell due to deformation of the cell case, a fire may occur or moisture in the air This may induce the generation of hydrogen fluoride due to this reaction, which causes various safety problems. For this reason, techniques relating to shock absorption have been proposed as in Patent Documents 1 and 2 below.

  In the following Patent Document 1, cylindrical cells are arranged substantially in parallel along the first and second wall surfaces separated in parallel, and the side surfaces of the adjacent cells are in contact with each other in the housing. A technology that disperses the impact force at the contact portion when the impact is applied because the line connecting the contact portions with the cells adjacent to the left and right of one cell is offset from the central axis of the cell. It is disclosed.

  In the following Patent Document 2, a cylindrical cell is built in, cells adjacent to each other are arranged in an offset shape, and the lead plate is formed in a zigzag shape so as to be connected to the end faces of these cells. When an impact is applied, a force that causes the cell to spread in a direction perpendicular to the impact force works, and when the impact force exceeds a certain level, the connection between the lead plate and the cell is disconnected and the cell is disassembled in the vertical direction. It is disclosed.

JP 2008-226544 A JP 2005-317458 A

  However, the techniques disclosed in Patent Documents 1 and 2 are assumed to be unable to cope with impacts from multiple directions.

  Therefore, an object of the present invention is to provide a battery pack that improves collision safety by providing an impact absorbing mechanism in the battery pack and preventing the cell case from being deformed against impacts from multiple directions.

The battery pack according to the first invention for solving the above-described problems is,
A plurality of modules having a plurality of cells and having rigid orthogonal anisotropy,
The adjacent modules are laid out so as to have different rigidity directions.

A battery pack according to a second invention for solving the above-mentioned problems is as follows.
In the battery pack according to the first invention,
The module is
A hollow housing with an opening,
Each of the openings of the housing is covered, and has an elastic membrane that deforms following the deformation of the housing,
The battery pack is laid in such a manner that opposing directions of the opening surfaces of the housing intersect each other.

A battery pack according to a third invention for solving the above-mentioned problem is as follows.
In the battery pack according to the second invention,
The casing has a hollow hexagonal prism shape, and grooves are disposed on the inner wall side of two sides that do not contact the adjacent module among the six parallel sides of the side surface, and slits are formed on the inner wall side of the other four sides. Is arranged,
A reinforcing member that extends on both sides of the groove in the housing with reference to the extending direction of the groove and restricts the deformation amount of the housing within a predetermined range is further provided. And

A battery pack according to a fourth invention for solving the above-mentioned problems is as follows.
In the battery pack according to the second invention,
The casing has a hollow rectangular parallelepiped shape, and grooves are arranged in the direction in which the opening surfaces of the casings of the two inner walls that do not contact the adjacent modules are opposed to each other on the inner wall side of four parallel sides. , Slits are arranged,
A reinforcing member that extends on both sides of the groove in the housing with reference to the extending direction of the groove and restricts the deformation amount of the housing within a predetermined range is further provided. And

A battery pack according to a fifth invention for solving the above-described problem is
In the battery pack according to the third or fourth invention,
The housing further includes a net for holding the cell so as not to fit into the groove.

  According to the present invention, it is possible to improve the collision safety without deforming the cell case against impacts from multiple directions.

It is the schematic of the battery pack which concerns on Example 1 of this invention. (A) represents a perspective view, and (b) represents a top view. It is a schematic perspective view of the module in Example 1 of this invention. (A) represents a state in which no cell is inserted, and (b) represents a state in which a cell is inserted. It is the schematic showing the mode of a deformation | transformation with respect to the impact of the battery pack which concerns on Example 1 of this invention. (A) represents a state before the deformation, (b) represents a state after the deformation by the collision 1, and (c) represents a state before the deformation by the collision 2. It is a schematic front view showing the mode of the deformation | transformation with respect to the impact of the module in Example 1 of this invention. (A) represents the state before a deformation | transformation, (b) represents the state after a deformation | transformation. It is a schematic diagram showing the mode of the deformation | transformation with respect to the impact around the groove | channel arrange | positioned at the module in Example 1 of this invention. (A) represents the state before a deformation | transformation, (b) represents the state after a deformation | transformation. It is a schematic perspective view of the battery pack according to Example 2 of the present invention. It is a schematic perspective view of the module in Example 2 of this invention. It is a schematic front view showing the mode of the deformation | transformation with respect to the impact of the module in Example 2 of this invention. (A) represents the state before a deformation | transformation, (b) represents the state after a deformation | transformation.

  Hereinafter, the battery pack according to the present invention will be described with reference to the drawings in the embodiments.

[Example 1]
The configuration of the battery pack according to Embodiment 1 of the present invention will be described with reference to FIGS. FIG. 1 is a schematic diagram of a battery pack according to Embodiment 1 of the present invention. FIG. 1A shows a perspective view, and FIG. 1B shows a top view. FIG. 2 is a schematic perspective view of the module according to the first embodiment of the present invention. FIG. 2A shows a state where no cell is inserted, and FIG. 2B shows a state where a cell is inserted.

  As shown in FIGS. 1 (a) and 1 (b), the battery pack according to the first embodiment of the present invention includes four modules 10, and the module 10 has no gap so as to have two-point symmetry. It is laid down.

  As shown in FIGS. 2 (a) and 2 (b), the module 10 incorporates a plurality of cylindrical cells 13 oriented substantially parallel to the axial direction, and includes a housing 11, an elastic membrane 12, and an inner reinforcement. A member 15, a net 16 and an outer reinforcing member 17 are provided.

  The casing 11 has a hollow hexagonal prism shape, and grooves 14a are formed on the inner wall side of two sides that do not contact the adjacent module 10 among six parallel sides that are sides of the side surface connecting the top surface and the bottom surface of the hexagonal column. It is arranged. Furthermore, the slit 14b is arrange | positioned by the inner wall side of four other sides. That is, a groove or a slit is provided on the inner wall side of the side in the height direction connecting the bottom surface and the top surface.

  The elastic films 12 are respectively covered at the opening end portions of the housing 11 and deformed following the deformation of the housing 11. In FIG. 2B, only one elastic film 12 is shown.

  The inner reinforcing member 15 is a triangular prism-like member disposed on both sides of the groove 14a in the housing 11 in parallel with the groove 14a. The inclination angle is defined so as to be limited within a range (predetermined range) where the angle is not crushed.

  The net 16 is mounted on the inner wall side of the lower two sides of the four sides where the slits 14 b are disposed in the housing 11, and holds the plurality of cells 13. However, the mounting position of the net 16 is not limited to this, and any position may be used as long as the cell 13 is held in the casing 11 so as not to fit into the groove 14a.

  The outer reinforcing member 17 is disposed at each of both ends of the four surfaces of the module 10 that are inclined with respect to the direction in which the module 10 is spread as described above, and the strength of the four surfaces. It is what raises.

  Due to the grooves 14a, the slits 14b, and the outer reinforcing member 17, the casing 11 has a hollow structure that does not allow deformation in the axial direction but allows deformation within a predetermined range in one direction perpendicular to the axial direction. . And the module 10 is spread in the said axial direction and the said one direction.

  What is important here is that the module 10 has rigid orthogonal anisotropy due to the configuration described above, and that the adjacent modules 10 are spread so as to be shifted by 90 °.

  The effect | action of the battery pack which concerns on Example 1 of this invention is demonstrated using FIGS. FIG. 3 is a schematic diagram illustrating a state of deformation with respect to an impact of the battery pack according to the first embodiment of the present invention. 3A shows a state before the deformation, FIG. 3B shows a state after the deformation by the collision 1, and FIG. 3C shows a state after the deformation by the collision 2. . FIG. 4 is a schematic front view showing a state of deformation of the module according to the first embodiment of the present invention with respect to impact. 4A shows a state before deformation, and FIG. 4B shows a state after deformation. FIG. 5 is a schematic diagram illustrating a state of deformation with respect to an impact around the groove disposed in the module according to the first embodiment of the present invention. FIG. 5A shows a state before deformation, and FIG. 5B shows a state after deformation.

  As shown in FIG. 3 (a), the state when collision 1 and collision 2 are applied to the battery pack according to Embodiment 1 of the present invention will be described. The collision 1 is an impact applied to the upper half module from the left side to the right side in the drawing, and the collision 2 is an impact applied to all the modules from the lower side to the upper side in the drawing. In addition, although each module with which the battery pack which concerns on Example 1 of this invention is equipped is made into the 1st module 10a, the 2nd module 10b, the 3rd module 10c, and the 4th module 10d, all are the above-mentioned structures. Same as module 10.

  When the collision 1 is applied, as shown in FIG. 3B, the second module 10b and the fourth module 10d are not deformed because no impact is applied. On the other hand, the third module 10c is deformed and can absorb the impact since the impact is applied from the direction allowing deformation. The first module 10a is not deformed because the third module 10c absorbs the impact and the impact is applied from a direction not allowing deformation.

  When the collision 2 is applied, as shown in FIG. 3C, the first module 10a and the fourth module 10d are deformed and absorb the shock because the shock is applied from the direction allowing deformation. it can. The second module 10b and the third module 10c are not deformed because the first module 10a and the fourth module 10d absorb the impact and the impact is applied from a direction not allowing deformation.

  Further, as shown in FIG. 4A, when an impact (a white arrow in the figure) is applied to the module 10 (may be the first to fourth modules 10a, 10b, 10c, and 10d) from the direction in which the deformation is allowed. As shown in FIG. 4B, the case 11 is deformed by closing the groove 14a disposed in the case 11 and opening the slit 14b. And the deformation | transformation amount of the housing | casing 11 is restrict | limited by the inner side reinforcement member 15, The internal cell 13 moves without deform | transforming and only arrangement | positioning changes. Although the elastic film 12 is not shown in FIGS. 4A and 4B, the elastic film 12 actually deforms following the deformation of the housing 11.

  Furthermore, it is preferable that a bus bar (not shown) connecting the cells 13 is cut when the arrangement of the cells 13 is changed.

  As shown in FIGS. 5 (a) and 5 (b), when the casing 11 is deformed by an impact, the inner reinforcing members 15 on both sides of the groove 14a come into contact with each other, and the deformation amount is limited to be within a predetermined range. . In addition, if the dimension is designed so that the cell 13 does not fit between the groove 14a or the inner reinforcing member 15, the mesh 16 may not be provided.

  In this embodiment, since the cell 13 moves in the module 10 when the module 10 is deformed due to an impact, a space is provided in the upper part of the module 10, that is, the cell 13 is provided with a space in the module 10. Built-in to ensure safety. However, depending on the design of the shape before and after the deformation, even if the cell 13 is filled in the module 10, safety can be ensured.

  In the above description, the cell 13 incorporated in the module 10 is a cylindrical cell. However, in this embodiment, it is not necessary to limit the shape of the cell. However, in the case of a cylindrical cell, the cell cannot move in the axial direction of the module. Therefore, when a conventional battery pack is used, an impact force is directly applied to the cell during an impact from the axial direction, and the cell case may be deformed. However, since this embodiment uses an impact absorbing mechanism that can handle impacts from multiple directions, this embodiment is more effective when the cell 13 built in the module 10 is a cylindrical cell. You can say that.

  Further, in the above description, the four modules 10 are described as being laid without gaps so as to have two-point symmetry, but the present embodiment does not limit the number of modules 10. Furthermore, it is not limited to two-point symmetry, and it is sufficient that the adjacent modules 10 are laid out in the axial direction and the one direction so that the adjacent modules 10 are shifted by 90 °. Good.

  The battery pack according to the first embodiment of the present invention has been described above. In other words, the battery pack according to the first embodiment of the present invention includes a plurality of cells 13 and does not allow deformation in the axial direction. The hollow casing 11 that allows deformation within a predetermined range in one direction perpendicular to the axial direction and the opening end of the casing 11 are respectively covered and follow the deformation of the casing 11. A plurality of modules 10 each having a deformable elastic film 12 are provided, and the modules 10 are arranged in the axial direction and the one direction so that the adjacent modules 10 are shifted by 90 °.

  And the housing | casing 11 is a hollow hexagonal column shape, The groove | channel 14a is arrange | positioned by the inner wall side of 2 sides which do not touch the adjacent module 10 among 6 parallel sides, and the inner wall side of 4 other sides, A slit 14b is provided, and is provided on both sides of the groove 14a in the housing 11 in parallel with the groove 14a, thereby limiting the deformation amount of the housing 11 within a predetermined range. A reinforcing member (inner reinforcing member 15) is provided.

  Moreover, in the housing | casing 11, you may make it provide the net | network 16 hold | maintained so that the cell 13 may not fit in the groove | channel 14a.

  In this way, the battery pack according to Embodiment 1 of the present invention can improve the collision safety without deforming the cell case against impacts from multiple directions.

[Example 2]
The battery pack according to Example 2 of the present invention is obtained by changing the shape of the module in Example 1.

  The configuration of the battery pack according to Embodiment 2 of the present invention will be described with reference to FIGS. FIG. 6 is a schematic perspective view of a battery pack according to Embodiment 2 of the present invention. FIG. 7 is a schematic perspective view of a module according to the second embodiment of the present invention.

  As shown in FIG. 6, the battery pack according to Embodiment 2 of the present invention includes four modules 20, and the modules 20 are spread without gaps so as to have two-point symmetry.

  As shown in FIG. 7, the module 20 includes a housing 21, an elastic film 22, an inner reinforcing member 25, a net 26, and an outer reinforcing member 27. Although not shown, the module 20 contains a plurality of cylindrical cells 13 oriented substantially parallel to the axial direction.

  The casing 21 has a hollow rectangular parallelepiped shape, and a groove 24 a is arranged in the axial direction of the center of the inner wall of two surfaces that do not contact the adjacent module 20. Furthermore, a slit 24b is disposed on the inner wall side of the side of the side that is the side connecting the top surface and the bottom surface. That is, the slit is provided on the inner wall side of the side in the height direction connecting the bottom surface and the top surface.

  The elastic films 22 are respectively covered at the opening end portions of the casing 21 and are deformed following the deformation of the casing 21. In FIG. 7, only one elastic film 22 is shown.

  The inner reinforcing member 25 is a triangular prism-like member disposed on both sides of the groove 24a in the housing 21 in parallel with the groove 24a. The inclination angle is defined so as to be limited within a range (predetermined range) where the angle is not crushed.

  The net 26 is mounted between the protrusions of the two inner reinforcing members 15. However, the mounting position of the net 26 is not limited to this, and any shape may be used as long as the cell 13 is held in the casing 21 so as not to fit into the groove 24a. However, as in the case of the mesh 16 in the first embodiment, the mesh 26 may not be provided if the dimensions are set so that the cell 13 does not fit between the groove 24a or the inner reinforcing member 25.

  The outer reinforcing member 27 is disposed at both ends of the two surfaces that do not contact the adjacent module 20, and increases the strength of the two surfaces.

  Due to the groove 24a, the slit 24b, and the outer reinforcing member 27, the casing 21 has a hollow structure that does not allow deformation in the axial direction but allows deformation within a predetermined range in one direction perpendicular to the axial direction. . And the module 20 is spread in the said axial direction and the said one direction.

  What is important here is that the module 20 has rigid orthogonal anisotropy due to the above-described configuration, and that the adjacent modules 20 are laid out in different stiffness directions. is there.

  The operation of the battery pack according to Embodiment 2 of the present invention will be described with reference to FIG. FIG. 8 is a schematic front view showing a state of deformation of the module according to the second embodiment of the present invention against impact. FIG. 8A shows a state before deformation, and FIG. 8B shows a state after deformation.

  As shown in FIG. 8A, when an impact (a white arrow in the figure) is applied from the direction in which the module 20 is allowed to be deformed, a groove disposed in the housing 21 as shown in FIG. The casing 21 is deformed by closing the 24a and opening the slit 24b. And the deformation | transformation amount of the housing | casing 21 is restrict | limited by the inner side reinforcement member 25, The internal cell 13 moves without deform | transforming and only arrangement | positioning changes. Although the elastic film 22 is not shown in FIGS. 8A and 8B, the elastic film 22 actually deforms following the deformation of the housing 21.

  Furthermore, it is preferable that a bus bar (not shown) connecting the cells 13 is cut when the arrangement of the cells 13 is changed.

  In the present embodiment, as in the first embodiment, whether the cell 13 is embedded with a space in the module 20 or whether the cell 13 is embedded so as to be filled in the module 20 is changed depending on the design. Is possible. Further, as in Example 1, it is not necessary to limit the shape of the cell, but it is more effective in the case of a cylindrical cell. Further, as in the first embodiment, the adjacent modules 20 need only be laid out in the axial direction and the one direction so as to be shifted by 90 °, and the numbers in the vertical and horizontal directions may be different.

  The battery pack according to the second embodiment of the present invention has been described above. In other words, the battery pack according to the second embodiment of the present invention includes a plurality of cells 13 and does not allow deformation in the axial direction. The hollow casing 21 that allows deformation within a predetermined range in one direction perpendicular to the axial direction and the opening end of the casing 21 are respectively covered and follow the deformation of the casing 21. A plurality of modules 20 each having a deformable elastic film 22 are provided, and the modules 20 are spread in the axial direction and the one direction so that the adjacent modules 20 have different rigid directions.

  The casing 21 has a hollow rectangular parallelepiped shape, and a groove 24a is disposed in the axial direction of the center of the inner wall of two surfaces that do not contact the adjacent module 20, and a slit 24b is formed on the inner wall side of the side between the side surfaces. Reinforcing members that are disposed on both sides of the groove 24a in the housing 21 in parallel with the groove 24a and restrict the deformation amount of the housing 21 within a predetermined range. An inner reinforcing member 25) is provided.

  Moreover, in the housing | casing 21, you may make it provide the net | network 26 hold | maintained so that the cell 13 may not fit in the groove | channel 24a.

  Thus, the battery pack according to Example 2 of the present invention can improve the collision safety without deforming the cell case with respect to the impact from multiple directions.

  As described above, the battery pack according to the present invention has been described using Examples 1 and 2. In other words, the battery pack according to the present invention includes a plurality of cells and has a rigid orthogonal anisotropy. Are installed in such a way that adjacent modules have different directions of rigidity. In this way, the cell case is not deformed against impacts from multiple directions, and collision safety is improved. It can be improved.

The exemplary embodiment of the present invention has been described above, but the present invention is of course not limited to this embodiment, and various modifications can be made without departing from the scope of the present invention.
In this embodiment, the adjacent modules are arranged so as to be shifted by 90 °. However, the present invention is not limited to this. For example, the adjacent modules may be shifted by 45 °. By doing so, it is possible to enhance the effect of absorbing an impact from an oblique direction. Of course, it is within the scope of the present invention when the same effect can be obtained at other angles.

  The present invention is suitable as a battery pack.

10, 20 module 10a first module 10b second module 10c third module 10d fourth module 11, 21 housing 12, 22 elastic membrane 13 cell 14a, 24a groove 14b, 24b slit 15, 25 inner reinforcing member 16, 26 net 17, 27 Outer reinforcement member

Claims (5)

A plurality of modules having a plurality of cells and having rigid orthogonal anisotropy,
A battery pack, wherein the adjacent modules are spread so as to have different rigidity directions. The module is
A hollow housing with an opening,
Each of the openings of the housing is covered, and has an elastic membrane that deforms following the deformation of the housing,
2. The battery pack according to claim 1, wherein the battery pack is laid in the battery pack such that opposing directions of the opening surfaces of the housing intersect each other. The casing has a hollow hexagonal prism shape, and grooves are disposed on the inner wall side of two sides that do not contact the adjacent module among the six parallel sides of the side surface, and slits are formed on the inner wall side of the other four sides. Is arranged,
A reinforcing member that extends on both sides of the groove in the housing with reference to the extending direction of the groove and restricts the deformation amount of the housing within a predetermined range is further provided. The battery pack according to claim 2. The casing has a hollow rectangular parallelepiped shape, and grooves are arranged in the direction in which the opening surfaces of the casings of the two inner walls that do not contact the adjacent modules are opposed to each other on the inner wall side of four parallel sides. , Slits are arranged,
A reinforcing member that extends on both sides of the groove in the housing with reference to the extending direction of the groove and restricts the deformation amount of the housing within a predetermined range is further provided. The battery pack according to claim 2.   5. The battery pack according to claim 3, further comprising a net that holds the cell so that the cell does not fit into the groove in the housing. 6.

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