JP2017111914A - Battery pack - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a battery pack which can ensure fixing strength for a battery module, while suppressing a reduction in heat dissipation of a battery cell.SOLUTION: A battery pack 100 comprises: a housing 2 having a first wall part 2s and a second wall part 2t which face each other; a battery module 1 having a plurality of battery cells 10 which are laminated along a first direction and are bound to each other, and a heat transfer surface 20s which faces the first wall part 2s and thermally connects the battery cells 10 to the housing 2; a bolt 51c which is arranged on the first wall part 2s and applies force in a second direction that is from the second wall part 2t toward the first wall part 2s so as to fasten the battery module 1 to the first wall part 2s; and a bolt 52d which is arranged on the second wall part 2t and applies force in the second direction so as to fasten the battery module 1 to the first wall part 2s. The first wall part 2s has a first region A facing the heat transfer surface 20s. The second wall part 2t has a second region B facing the first region A with the battery module 1 sandwiched therebetween. The bolt 52d is arranged in the second region B.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a battery pack.

  Conventionally, as a technology related to a battery pack, an assembled battery including a plurality of power storage elements, an exterior body that stores the power storage elements, and a restraining member that sandwiches and consolidates the plurality of power storage elements is known (for example, a patent) Reference 1).

JP 2014-216189 A

  In the above assembled battery, in order to promote heat dissipation from the power storage element to the exterior body, it is considered that a plurality of power storage elements are fixed to the exterior body in a state where a predetermined heat transfer surface of the power storage element is in contact with the exterior body. It is done. As a method for fixing the power storage element to the exterior body, for example, a method of fastening the power storage element with bolts to the first wall portion located on the heat transfer surface side of the exterior body is conceivable. In this case, from the viewpoint of securing the fixing strength of the power storage element, it is desirable to further fasten the power storage element with bolts to the second wall portion facing the first wall portion in the exterior body. However, in this case, due to the fastening in the second wall portion, a force in the direction of separating the heat transfer surface from the first wall portion may act on the power storage element, and the heat dissipation of the power storage element may be reduced.

  This invention is made in view of such a situation, and it aims at providing the battery pack which can ensure the fixed intensity | strength of a battery module, suppressing the fall of the heat dissipation of a battery cell.

  The battery pack according to the present invention has a casing having a first wall portion and a second wall portion facing each other, a plurality of battery cells stacked in a first direction and constrained to each other, and facing the first wall portion. A battery module having a heat transfer surface for thermally connecting the battery cell to the housing, and the battery module in the second direction from the second wall toward the first wall. A first fastening member that applies a force to fasten the battery module to the first wall, and a second fastening member that is provided on the second wall and applies the force to the battery module in the second direction to fasten the battery module to the first wall. 2 fastening members, the first wall portion has a first region facing the heat transfer surface, and the second wall portion has a second region facing the first region across the battery module. The second fastening member is disposed in the second region.

  In this battery pack, the battery module is fastened to the first wall portion by a first fastening member provided on the first wall portion of the housing. Further, the battery module is fastened to the first wall portion by a second fastening member provided on the second wall portion facing the first wall portion of the housing. For this reason, the fixing strength to the housing | casing of a battery module is ensured. In particular, here, the force applied to the battery module by the first fastening member and the force applied to the battery module by the second fastening member are both forces in the second direction from the second wall portion toward the first wall portion. It is. For this reason, when fixing a battery module to a housing | casing, the force of the direction which separates a heat-transfer surface from a 1st wall part is hard to be applied to a battery module. Therefore, a decrease in heat dissipation of the battery cell is suppressed.

  In the battery pack according to the present invention, the first direction is a direction along the extending direction of the first wall, and the battery module includes one end including the battery cell on one end side in the first direction, and the first direction. The other end portion including the battery cell on the other end side, and an intermediate portion between the one end portion and the other end portion, and the first fastening member includes the battery module at the one end portion and the other end portion of the battery module. The second fastening member may be fastened to the first wall portion, and may apply force to the battery module at the intermediate portion. In this case, in the battery module, the plurality of battery cells are stacked along the direction along the extending direction of the first wall and are constrained to each other. The battery module is fastened to the first wall portion at one end and the other end of the battery module by a first fastening member. Therefore, the positional deviation of the battery cell in the direction in which the heat transfer surface is separated from the first wall portion is likely to occur at the intermediate portion as compared with the one end portion and the other end portion. Therefore, when the second fastening member applies a force to the battery module in the intermediate portion, it is possible to suppress the positional deviation of the battery cell in the direction in which the heat transfer surface is separated from the first wall portion, and it is possible to suppress the deterioration of the heat dissipation of the battery cell. The

  In the battery pack according to the present invention, the battery module has a plate member extending over the plurality of battery cells on the second wall side, and the second fastening member applies a force to the battery module via the plate member. May be. In this case, since the second fastening member applies a force to the battery module via the plate member extending over the plurality of battery cells, the second fastening member can apply a force to each of the plurality of battery cells.

  In the battery pack according to the present invention, the plate member may be provided with a recess in which the second fastening member is disposed. In this case, the relative movement of the plate member with respect to the second fastening member can be suppressed.

  In the battery pack according to the present invention, the first direction is a direction along the second direction, and the second fastening member may apply a force to the central portion of the battery cell when viewed from the first direction. . In the battery module, a plurality of battery cells are stacked along the second direction from the second wall portion toward the first wall portion and are constrained to each other. In this case, for example, when the central portion of the battery cell expands relatively greatly, there is a possibility that a positional shift in the direction of separating the heat transfer surface from the first wall portion may occur. Therefore, when the second fastening member applies a force to the battery module in the central portion, it is possible to suppress a positional shift in a direction in which the heat transfer surface is separated from the first wall portion, and a decrease in heat dissipation of the battery cell is suppressed.

  In the battery pack according to the present invention, the battery module may be provided with a recess in which the second fastening member is disposed. In this case, the relative movement of the battery module with respect to the second fastening member can be suppressed.

  ADVANTAGE OF THE INVENTION According to this invention, the battery pack which can ensure the fixed strength of a battery module can be provided, suppressing the fall of the heat dissipation of a battery cell.

It is sectional drawing which shows the partial structure of the battery pack which concerns on one Embodiment. FIG. 2 is a partial exploded perspective view of the battery module shown in FIG. 1. It is sectional drawing which shows the partial structure of the battery pack which concerns on a 1st modification. It is a typical perspective view of the battery pack which concerns on a 2nd modification. It is sectional drawing which shows the partial structure of the battery pack which concerns on a 2nd modification.

[Embodiment]
Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. In the description of the drawings, the same elements or corresponding elements may be assigned the same reference numerals, and overlapping descriptions may be omitted. In the following drawings, an orthogonal coordinate system S may be shown.

  FIG. 1 is a cross-sectional view showing a partial configuration of a battery pack according to an embodiment. As shown in FIG. 1, the battery pack 100 includes a battery module 1, a housing 2, and a heat conduction member (TIM: Thermal Interface Material) 3. The battery module 1 is accommodated in the housing 2. The housing 2 has a first wall portion 2s and a second wall portion 2t facing each other. The first wall 2s and the second wall 2t are connected and integrated with each other by, for example, a side wall 2u. The battery module 1 is fixed to the first wall 2s of the housing 2 (details will be described later). The heat conducting member 3 is disposed between the battery module 1 and the first wall 2 s of the housing 2. The battery pack 100 can include, for example, a plurality of battery modules 1 stacked along the first wall 2s, but only one battery module 1 is illustrated here.

  The battery module 1 includes a stacked body 30 including a plurality of battery cells 10 and a plurality of heat transfer plates 20. The number of battery cells 10 is, for example, seven. Each battery cell 10 is individually held by a cell holder 40 (see FIG. 2). The heat transfer plate 20 is provided for each of the battery cells 10. Therefore, the number of heat transfer plates 20 is also seven as an example. The plurality of battery cells 10 and the heat transfer plate 20 are stacked along the first direction (X-axis direction) along the extending direction of the first wall 2s and are constrained to each other.

  FIG. 2 is a partially exploded perspective view of the battery module shown in FIG. As shown in FIG. 2, the battery cell 10 is electrically connected to the electrode assembly 11, the case 12 that houses the electrode assembly 11, and the electrodes (each of the positive electrode and the negative electrode) of the electrode assembly 11, A pair of terminals 13 protruding from the case 12. The electrode assembly 11 includes a plurality of positive electrodes (not shown) and a negative electrode (not shown), and a separator (not shown) disposed between the positive electrode and the negative electrode. The positive electrode and the negative electrode are alternately stacked via separators. The stacking direction of the positive electrode and the negative electrode substantially coincides with the stacking direction of the battery cells 10 (first direction: X-axis direction).

  The case 12 has a rectangular parallelepiped shape. The case 12 includes a pair of side surfaces 12a and 12b facing each other, a pair of side surfaces 12c and 12d facing each other, and a top surface 12e and a bottom surface 12f facing each other. The side surfaces 12a and 12b are surfaces along the first direction. The side surfaces 12c and 12d are surfaces along a second direction (Y-axis direction) that intersects the first direction, and are surfaces that connect the side surface 12a and the side surface 12b to each other. The terminal 13 protrudes from the upper surface 12e.

  The cell holder 40 includes a pair of side wall portions 40a, 40b facing each other, a back surface portion 40e, and a bottom wall portion 40f. The side wall portions 40a and 40b have a rectangular plate shape. The back surface portion 40e has a rectangular plate shape, and connects the side wall portion 40a and the side wall portion 40b to each other at one end portion in the longitudinal direction of the side wall portions 40a and 40b. The bottom wall portion 40f has a rectangular plate shape, and connects the side wall portion 40a and the side wall portion 40b to each other at the other end portion in the longitudinal direction of the side wall portions 40a and 40b.

  In the cell holder 40, a rectangular parallelepiped space portion into which the battery cell 10 is fitted is defined by the side wall portions 40a, 40b, the back surface portion 40e, and the bottom wall portion 40f. The side wall portions 40a and 40b are respectively disposed on the side surfaces 12a and 12b of the case 12 when the battery cell 10 is fitted in the space portion. Similarly, the back surface portion 40 e is disposed on the side surface 12 d in the vicinity of the top surface 12 e of the case 12. Further, the bottom wall portion 40 f is disposed on the bottom surface 12 f of the case 12.

  A pair of projecting portions 41 is provided on the back surface portion 40e. The protruding portion 41 has a cylindrical shape. The protruding portion 41 extends along the first direction. The protruding portion 41 is disposed on the upper surface 12 e of the case 12 and between the pair of terminals 13 when the battery cell 10 is fitted into the space portion of the cell holder 40. The projecting portion 41 is formed with a through hole 41h along the extending direction. A bolt of a restraining member, which will be described later, is inserted into the through hole 41h.

  In addition, a pair of projecting portions 42 are provided at a connection portion between the bottom wall portion 40f and the side wall portions 40a and 40b. The protruding portion 42 has a rectangular parallelepiped shape. The protruding portion 42 extends along the first direction. When the battery cell 10 is fitted into the space portion of the cell holder 40, the protruding portion 42 is disposed at the end on the side surface 12a, 12b side of the bottom surface 12f of the case 12. The protruding portion 42 is formed with a through hole 42h along the extending direction. A bolt of a restraining member to be described later is inserted into the through hole 42h.

  The heat transfer plate 20 includes a rectangular plate-shaped main body portion 21 and a rectangular plate-shaped extension portion 22. The heat transfer plate 20 is formed in an L-shaped plate shape by the main body portion 21 and the extending portion 22. The main body 21 is disposed on the side surface 12d of the battery cell 10 (case 12). The extending portion 22 extends from the main body portion 21 along the first direction, and is disposed on the side surface 12a of the battery cell 10 (case 12). In particular, the surface of the extension 22 opposite to the side wall 40 a is a heat transfer surface 20 s that thermally connects the battery cell 10 and the housing 2 via the heat conducting member 3. That is, the battery module 1 has a heat transfer surface 20 s that faces the first wall portion 2 s and thermally connects the battery cell 10 to the housing 2. The heat transfer plate 20 is attached to the battery cell 10 so that the fixed portion 51b of the end plate 51 and the heat transfer surface 20s in the battery module 1 are located on the same side.

  The description of each part of the battery module 1 will be continued with reference to FIG. The battery module 1 includes a restraining member 50, a middle plate 60, and an elastic body 70. The restraining member 50 restrains the battery cell 10 and the heat transfer plate 20 along the stacking direction of the battery cells 10. More specifically, the restraining member 50 includes a pair of end plates 51 and a plurality of bolts and nuts (not shown).

  The end plate 51 is disposed on each of the one end 30a and the other end 30b of the stacked body 30 in the first direction. As an example, the end plate 51 is formed in an L-shaped plate shape by a rectangular plate-shaped main body portion 51a and a rectangular plate-shaped fixing portion 51b. The main body 51 a is disposed on the side surfaces 12 c and 12 d of the battery cell 10. The fixing portion 51b is provided so as to protrude from the main body portion 51a along the first direction. The end plate 51 adds a restraining load to the battery cell 10 by being sandwiched between bolts and nuts. The middle plate 60 is disposed between the one end 30 a of the stacked body 30 and the end plate 51. The elastic body 70 is made of, for example, rubber or the like, and is disposed between the middle plate 60 and the end plate 51.

  The battery module 1 configured as described above is fastened to the first wall 2s of the housing 2 by bolts (first fastening members) 51c provided on the first wall 2s at both ends in the first direction. Yes. More specifically, the battery module 1 uses the bolt 51c inserted into the fixing portion 51b in a state where the fixing portion 51b of the end plate 51 is in contact with the first wall portion 2s of the casing 2. The first wall portion 2s is fixed. That is, the bolt 51c applies a force to the battery module 1 in the second direction from the second wall 2t to the first wall 2s to fasten the battery module 1 to the first wall 2s.

  The battery module 1 is fastened to the first wall 2s of the housing 2 by a bolt (second fastening member) 52d provided on the second wall 2t. More specifically, the bolt 52d is disposed in the second region B of the second wall 2t. The second region B is a region facing the first region A across the battery module 1 in the second wall 2t. The first region A is a region facing the heat transfer surface 20s in the first wall 2s. In the second region B, the bolt 52d is screwed into a screw portion 52e provided in the housing 2 on the second wall 2t side. When the bolt 52d is tightened in the second direction, a force is applied to the battery module 1 in the second direction from the second wall 2t toward the first wall 2s, and the battery module 1 is fastened to the first wall 2s. Is done. That is, the bolt 52d applies a force to the battery module 1 in the second direction to fasten the battery module 1 to the first wall 2s.

  In addition, the battery module 1 includes one end 1a including the battery cell 10 at one end 30a (one end side in the first direction) of the stacked body 30, and the other end 30b (the other end side in the first direction) of the stacked body 30. ) Including the battery cell 10 and an intermediate portion 1c between the one end 1a and the other end 1b. The one end portion 1 a here includes, as an example, only the battery cell 10 adjacent to the end plate 51 in the one end portion 30 a of the stacked body 30. Moreover, the other end part 1b here contains only the battery cell 10 adjacent to the end plate 51 in the other end part 30b of the laminated body 30 as an example. Therefore, the intermediate part 1 c here includes five battery cells other than the battery cells 10 and 10 adjacent to the pair of end plates 51 and 51. Note that the one end 1 a may include a plurality of battery cells 10 at one end 30 a of the stacked body 30, and the other end 1 b may include a plurality of battery cells 10 at the other end 30 b of the stacked body 30.

  The battery module 1 is fastened to the first wall 2s at one end 1a and the other end 1b of the battery module 1 by bolts 51c. The battery module 1 is applied with a force at the intermediate portion 1c by a bolt 52d. Here, the battery module 1 is applied with a force in the battery cell 10 located in the center among the five battery cells included in the intermediate portion 1c by the bolt 52d. The position where the force is applied by the bolt 52d in the intermediate part 1c is not limited to this example, and may be a different position as long as it is within the range of the intermediate part 1c. In particular, the position may be shifted to the elastic body 70 side from the center among the five battery cells included in the intermediate portion 1c.

  The battery module 1 includes a plate member 53 that extends over the plurality of battery cells 10 on the second wall 2t side. The bolt 52 d applies a force to the battery module 1 through the plate member 53. For example, the plate member 53 contacts the plurality of battery cells 10 at the surface portion 53a. The plate member 53 disperses the force in the second direction applied using the bolts 52d to each of the plurality of battery cells 10. The plate member 53 is provided with a concave portion 53c in which a bolt 52d is disposed on a surface portion 53b opposite to the battery cell 10, and the concave portion 52c is fitted to a tip portion of the bolt 52d as an example. The recess 52c restricts relative movement between the plate member 53 and the second wall 2t in the direction along the second wall 2t.

  As described above, in the battery pack 100 according to the present embodiment, the battery module 1 is fastened to the first wall 2s by the bolts 51c provided on the first wall 2s of the housing 2. The battery module 1 is fastened to the first wall portion 2s by a bolt 52d provided on the second wall portion 2t facing the first wall portion 2s of the housing 2. For this reason, the fixing strength to the housing | casing of a battery module is ensured.

  Here, in general, from the viewpoint of securing the fixing strength of the battery cell, when the battery cell is further fastened to the second wall portion facing the first wall portion of the housing by the bolt, the second By fastening at the wall, a force in the direction of separating the heat transfer surface from the first wall acts on the battery cell (battery module), and the heat dissipation of the battery cell may be reduced.

  In this respect, in the battery pack 100, the force applied to the battery module 1 by the bolt 51c and the force applied to the battery module 1 by the bolt 52d are both from the second wall 2t toward the first wall 2s. Force in two directions. For this reason, when fixing the battery module 1 to the housing | casing 2, the force of the direction which pulls the heat-transfer surface 20s away from the 1st wall part 2s is hard to be applied to the battery module 1. FIG. Therefore, a decrease in heat dissipation of the battery cell 10 is suppressed.

  In the battery pack 100, the bolt 51c fastens the battery module to the first wall 2s at one end 1a and the other end 1b of the battery module 1, and the bolt 52d applies force to the battery module 1 at the intermediate portion 1c. Is added. In the battery module 1, the plurality of battery cells 10 are stacked and constrained to each other along the direction along the extending direction of the first wall 2 s. The battery module 1 is fastened to the first wall 2s at one end 1a and the other end 1b of the battery module 1 by bolts 51c. Therefore, the positional deviation of the battery cell 10 in the direction in which the heat transfer surface 20 s is separated from the first wall 2 s is likely to occur in the intermediate portion 1 c as compared with the one end 1 a and the other end 1 b. Therefore, the bolt 52d applies a force to the battery module 1 in the intermediate portion 1c, so that the displacement of the battery cell 10 in the direction of separating the heat transfer surface 20s from the first wall portion 2s can be suppressed, and the heat dissipation of the battery cell 10 can be suppressed. Reduction is suppressed.

  Further, in the battery pack 100, the battery module 1 has a plate member 53 extending over the plurality of battery cells 10 on the second wall 2t side, and the bolt 52d is connected to the battery module 1 via the plate member 53. I am adding power. Thereby, since the bolt 52d applies a force to the battery module 1 via the plate member 53 extending over the plurality of battery cells 10, it is possible to apply a force to each of the stacked battery cells 10.

  In the battery pack 100, the plate member 53 may be provided with a recess 53c in which the bolt 52d is disposed. In this case, relative movement of the plate member 53 with respect to the bolt 52d can be suppressed.

[First Modification]
A modification of the battery pack 100 according to the present embodiment will be described. FIG. 3 is a cross-sectional view showing a partial configuration of the battery pack according to the first modification. As shown in FIG. 3, in the battery pack 100 </ b> A according to the first modified example, the direction in which the battery module 1 </ b> A is fixed to the housing 2 is such that the battery module 1 is attached to the housing 2 in the battery pack 100. It is different from the fixing direction.

  Specifically, in the battery module 1A, the plurality of battery cells 10 are stacked and restrained from each other along the second direction from the second wall 2t to the first wall 2s. That is, in the battery pack 100A, the first direction is a direction along the second direction.

  The battery module 1 </ b> A includes a heat transfer plate 23 in addition to the plurality of heat transfer plates 20. The heat transfer plate 23 is a member for transmitting heat from the plurality of battery cells 10 to the first wall 2s. The heat transfer plate 23 includes a rectangular plate-shaped main body portion 24 and a rectangular plate-shaped extension portion 25. The heat transfer plate 23 is formed in an L-shaped plate shape by the main body portion 24 and the extending portion 25. The main body 24 is disposed on the heat transfer surfaces 20 s of the plurality of heat transfer plates 20. The extending part 25 extends along the direction intersecting the first direction from the main body part 24, and is disposed on the main body part 21 of the heat transfer plate 20 in the one end part 30 a of the stacked body 30. Further, the heat conducting member 3 and the end plate 54 are interposed between the extending portion 25 and the first wall portion 2s. Therefore, the surface of the extending portion 25 opposite to the main body portion 21 is a heat transfer surface 23 s that thermally connects the battery cell 10 and the housing 2 via the heat conducting member 3 and the end plate 54. That is, the battery module 1 </ b> A has a heat transfer surface 23 s that faces the first wall portion 2 s and thermally connects the battery cell 10 to the housing 2.

  The battery module 1 </ b> A has a restraining member 50. The restraining member 50 includes a pair of end plates 54 and 55 and a plurality of bolts and nuts (not shown).

  The end plate 54 is disposed at one end 30a of the stacked body 30 in the first direction. The end plate 54 is formed in a rectangular plate shape as an example. A bolt 51c is screwed to the end plate 54 via the first wall 2s.

  The end plate 55 is disposed at the other end 30b of the stacked body 30 in the first direction. The end plate 55 is formed in a rectangular plate shape as an example. The end plate 55 is provided with a recess 55c in which the bolt 52d is disposed. The bolt 52d and the recess 55c are provided in the central portion C of the battery cell 10 when viewed from the first direction. The center part C can be made into the part containing the intersection of the diagonal in the side surfaces 12c and 12d of the battery cell 10 when it sees from a 1st direction, for example.

  The battery module 1A configured as described above is fastened to the first wall 2s of the housing 2 by bolts 51c provided on the first wall 2s at both ends in the first direction (second direction). . More specifically, the battery module 1 </ b> A uses the bolt 51 c screwed to the end plate 51 in a state where the end plate 51 is in contact with the first wall 2 s of the casing 2. It is fixed to the wall 2s. That is, the bolt 51c applies a force to the battery module 1A in the second direction from the second wall 2t to the first wall 2s to fasten the battery module 1 to the first wall 2s.

  The battery module 1A is fastened to the first wall 2s of the housing 2 by a bolt 52d provided on the second wall 2t. More specifically, the bolt 52d is disposed in the second region B of the second wall 2t. The second region B is a region facing the first region A across the battery module 1A in the second wall 2t. The first region A is a region facing the heat transfer surface 23s in the first wall 2s. In the second region B, the bolt 52d is screwed into a screw portion 52e provided in the housing 2 on the second wall 2t side. When the bolt 52d is tightened in the second direction, a force is applied to the battery module 1A in the direction from the second wall 2t to the first wall 2s, and the battery module 1A is fastened to the first wall 2s. . That is, the bolt 52d applies a force to the battery module 1A in the second direction to fasten the battery module 1A to the first wall 2s. In particular, the bolt 52d applies a force to the central portion C of the battery cell 10 when viewed from the first direction.

  In the battery pack 100A according to this modification, the first direction is a direction along the second direction, and the bolt 52d applies a force to the central portion C of the battery cell 10 when viewed from the first direction. Yes. In the battery module 1A, the plurality of battery cells 10 are stacked and restrained from each other along the second direction from the second wall 2t to the first wall 2s. In this case, for example, when the central portion C of the battery cell 10 expands relatively large, there is a possibility that a positional shift in the direction of separating the heat transfer surface 20s from the first wall portion 2s may occur. Therefore, when the bolt 52d applies a force to the battery module 1A in the central portion C, it is possible to suppress the positional deviation in the direction in which the heat transfer surface 20s is separated from the first wall portion 2s, and the deterioration of the heat dissipation of the battery cell 10 is suppressed. Is done.

  In the battery pack 100A, the battery module 1A is provided with a recess 53c in which the bolt 52d is disposed. Thereby, relative movement of the end plate 55 (battery module 1A) with respect to the bolt 52d can be suppressed.

[Second Modification]
Another modification of the battery pack 100 will be described. FIG. 4 is a schematic perspective view of a battery pack according to a second modification. FIG. 5 is a cross-sectional view showing a partial configuration of a battery pack according to a second modification. As shown in FIGS. 4 and 5, the battery pack 100 </ b> B according to the second modified example is configured by housing a plurality of battery modules 1 </ b> B in a housing 2 that forms a substantially rectangular parallelepiped box as a whole. Has been. The housing 2 has a bottomed main body 2a and a lid 2b that closes an opening on one surface of the main body 2a.

  A frame 81 is used for housing the battery module 1 </ b> B in the housing 2. The frame 81 is configured by connecting, for example, metal beam portions 82 by welding or the like, and has a substantially rectangular parallelepiped shape that fits into the housing 2. The beam portion 82 has, for example, a bar shape with a square cross section, and includes an outer portion that forms a substantially rectangular parallelepiped outer shape of the frame 81 and an inner portion that connects the midpoints of the outer portion. As a result, a plurality of substantially rectangular parallelepiped assembling regions K for assembling the battery module 1 </ b> B are formed in the frame 81.

  The battery module 1 </ b> B includes a stacked body 30 including a plurality of battery cells 10 and a plurality of heat transfer plates 20. The plurality of battery cells 10 and the heat transfer plate 20 are stacked along the first direction (X-axis direction) along the extending direction of the first wall 2s and are constrained to each other. The battery module 1 </ b> B includes a bracket (restraining member) 56 that applies a restraining load to the stacked body 30 in the first direction.

  The restraining member includes a pair of brackets 56 and a fastening member that fastens the brackets 56 together. The bracket 56 is a substantially rectangular flat plate member that also functions as an end plate of the stacked body 30. The brackets 56 are respectively disposed at both ends of the battery cell 10 in the stacking direction (first direction) so as to sandwich the stacked body 30 and the elastic body (not shown). The fastening member includes, for example, a long bolt 57 and a nut (not shown) that is screwed to the bolt 57.

  As shown in FIG. 5, the frame body 81 is fitted in the housing 2. Further, the battery module 1 </ b> B is assembled to the assembly region K of the frame body 81. In assembling the battery module 1B and the frame 81, for example, the bracket 56 in the battery module 1B is stretched over a pair of beam portions 82 and 82 and fixed by bolts (not shown).

  As an example, the battery module 1B is attached to the frame 81 so that the side surface 82s of the beam portion 82 and the heat transfer surface 20s are flush with each other. That is, the battery module 1 </ b> B is attached to the frame body 81 so that the heat transfer surface 20 s contacts the first wall portion 2 s in a state where the frame body 81 is fitted in the housing 2. A heat conduction member may be provided between the heat transfer surface 20s and the first wall 2s.

  In the battery pack 100B configured as described above, the frame 81 is fastened to the first wall 2s of the housing 2 by the bolts 51c provided on the first wall 2s. More specifically, the frame body 81 to which the battery module 1B is attached is inserted into the first wall portion 2s in a state where the side surface 82s of the beam portion 82 is in contact with the first wall portion 2s of the housing 2. It is fixed to the first wall 2 s of the housing 2 using a bolt 51 c. That is, the bolt 51c applies a force to the battery module 1B via the frame 81 in the second direction from the second wall 2t toward the first wall 2s, and causes the battery module 1B to be Fasten to wall 2s.

  The battery module 1B is fastened to the first wall 2s of the housing 2 by a bolt 52d provided on the second wall 2t. More specifically, the bolt 52d is disposed in the second region B of the second wall 2t. The second region B is a region facing the first region A across the battery module 1B on the second wall 2t. The first region A is a region facing the heat transfer surface 20s in the first wall 2s. In the second region B, the bolt 52d is screwed into a screw portion 52e provided in the housing 2 on the second wall 2t side. By tightening the bolt 52d in the second direction, a force is applied to the battery module 1B in the second direction from the second wall 2t toward the first wall 2s, and the battery module 1B is Fastened to one wall 2s. The battery module 1B includes a plate member 83 extending over the plurality of battery cells 10 on the second wall 2t side. The bolt 52d applies a force to the battery module 1B via the plate member 83. That is, the bolt 52d applies a force to the battery module 1B in the second direction to fasten the battery module 1B to the first wall 2s.

  As described above, the battery pack 100 </ b> B also has the same operations and effects as the battery pack 100. That is, the battery module 1B is fastened to the first wall 2s by the bolts 51c provided on the first wall 2s of the housing 2. The battery module 1B is fastened to the first wall portion 2s by a bolt 52d provided on the second wall portion 2t facing the first wall portion 2s of the housing 2. For this reason, the fixing strength to the housing | casing of a battery module is ensured. In the battery pack 100B, the force applied to the battery module 1B by the bolt 51c via the frame 81 and the force applied to the battery module 1B by the bolt 52d are both from the second wall portion 2t to the first wall. This is the force in the second direction toward the portion 2s. For this reason, when fixing the battery module 1B to the housing | casing 2, the force of the direction which separates the heat-transfer surface 20s from the 1st wall part 2s is hard to be applied to the battery module 1B. Therefore, a decrease in heat dissipation of the battery cell 10 is suppressed.

  The above embodiment describes one embodiment of the battery pack according to the present invention. Therefore, the battery pack according to the present invention is not limited to the battery packs 100, 100A, and 100B described above. In the battery pack according to the present invention, the above-described battery packs 100, 100A, and 100B can be arbitrarily modified without changing the gist of each claim.

  For example, the bolt 51c provided on the first wall 2s fastens the battery module 1, 1A or 1B so as to press the battery module 1, 1A or 1B against the first wall 2s as in the battery pack 100. Alternatively, like the battery packs 100A and 100B, the battery module 1, 1A, or 1B may be fastened by pulling the battery module 1, 1A, or 1B toward the first wall 2s side.

  Moreover, although the bolt 51c and the bolt 52d showed the headed bolt as an example, if force can be applied so that the battery module 1, 1A, or 1B may be fastened to the 1st wall part 2s, other shapes are used. Bolts may be used.

Further, the target to which the battery module 1 is fastened is not necessarily the housing 2. For example, when the first wall part and the second wall part face each other in the first external part having the first wall part and the second external part having the second wall part, the battery module is placed on the first wall part. 1 may be fastened. This point is described below.
[Appendix]
A battery module fixed between a first external part having a first wall part and a second external part having a second wall part,
A plurality of battery cells stacked along the first direction and constrained to each other; and a heat transfer surface that faces the first wall portion and thermally connects the battery cells to the first external component,
The first wall and the second wall are opposed to each other;
The first wall has a first region facing the heat transfer surface,
The second wall portion has a second region facing the first region across the plurality of battery cells,
A force is applied in a second direction from the second wall portion toward the first wall portion by a first fastening member provided on the first wall portion, and the first wall portion is fastened to the first wall portion,
A force is applied in the second direction by a second fastening member disposed in the second region of the second wall portion to be fastened to the first wall portion;
Battery module.

  DESCRIPTION OF SYMBOLS 1, 1A, 1B ... Battery module, 1a ... One end part, 1b ... Other end part, 1c ... Middle part, 2 ... Housing | casing, 2s ... 1st wall part, 2t ... 2nd wall part, 10 ... Battery cell, 20s , 23s ... heat transfer surface, 51c ... bolt (first fastening member), 52c ... recess, 52d ... bolt (second fastening member), 53, 83 ... plate member, 53c ... recess, 55 ... end plate (plate member) , 55c ... concave portion, 100, 100, 100A ... battery pack, A ... first region, B ... second region, C ... central portion.

Claims (6)

A housing having a first wall portion and a second wall portion facing each other;
A battery module having a plurality of battery cells stacked along the first direction and constrained to each other; and a heat transfer surface that faces the first wall and thermally connects the battery cells to the housing; ,
A first fastening member that is provided on the first wall portion and applies a force to the battery module in a second direction from the second wall portion toward the first wall portion to fasten the battery module to the first wall portion. When,
A second fastening member that is provided on the second wall and applies a force to the battery module in the second direction to fasten the battery module to the first wall;
With
The first wall has a first region facing the heat transfer surface,
The second wall portion has a second region facing the first region across the battery module,
The second fastening member is disposed in the second region,
Battery pack. The first direction is a direction along the extending direction of the first wall portion,
The battery module includes one end including the battery cell on one end in the first direction, the other end including the battery cell on the other end in the first direction, the one end, and the other end. And an intermediate part between
The first fastening member fastens the battery module to the first wall at the one end and the other end of the battery module,
The second fastening member applies force to the battery module at the intermediate portion;
The battery pack according to claim 1. The battery module has a plate member extending over the plurality of battery cells on the second wall side,
The second fastening member applies a force to the battery module via the plate member;
The battery pack according to claim 2. The plate member is provided with a recess in which the second fastening member is disposed.
The battery pack according to claim 3. The first direction is a direction along the second direction,
The second fastening member applies a force to a central portion of the battery cell when viewed from the first direction;
The battery pack according to claim 1.   The battery pack according to claim 5, wherein the battery module is provided with a recess in which the second fastening member is disposed.

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