JP6661922B2 - Battery module and method of manufacturing battery module - Google Patents

Description

  The present invention relates to a battery module and a method for manufacturing a battery module.

  For example, the battery module described in Patent Literature 1 includes an array in which a plurality of battery cells held by a cell holder are arrayed, and a restraint member that restrains the array by pressing the array in the battery cell array direction. ing. In this battery module, a protrusion is provided on one surface of the cell holder in the arrangement direction, and a recess is provided on the other surface. By fitting these protrusions and recesses, the displacement of the cell holder in the direction orthogonal to the arrangement direction is suppressed, and the seriality of the arrangement is ensured.

JP 2011-222490 A

  In the battery module of Patent Literature 1, when the battery cells expand in the arrangement direction due to deterioration, overcharging, or the like, the distance between adjacent cell holders may increase, and the protruding portion may fall out of the concave portion. In this case, there is a possibility that the position of the cell holder is shifted in a direction orthogonal to the arrangement direction, and the seriality of the array body is impaired.

  An object of the present invention is to provide a battery module that can maintain the seriality of an array even when a battery cell expands, and a method of manufacturing a battery module that can manufacture such a battery module.

  A battery module according to one aspect of the present invention includes an array body that is held by a cell holder and includes a plurality of battery cells arranged along a predetermined array direction, without sandwiching an elastic member between the battery cells. An elastic member disposed at both ends in the arrangement direction of the array and at least one location between the battery cells so that adjacent pairs of non-sandwiched cell holders exist; and a restraining member for pressing and restraining the array and the elastic member in the array direction. And one of the adjacent cell holders is provided with a protrusion that projects in the arrangement direction from a surface facing the other of the adjacent cell holders, and the other of the adjacent cell holders has a recess in which the protrusion is disposed. In the non-clamped cell holder pair provided, the insertion length of the protruding portion in the arrangement direction with respect to the concave portion is equal to or more than the allowable compression amount of the elastic member per battery cell against expansion of the battery cell. You have me.

  In this battery module, when the battery cell expands, the elastic member is compressed and deformed, thereby allowing the battery cell to expand. At this time, in the pair of non-clamped cell holders adjacent to each other without sandwiching the elastic member between the battery cells, the distance between the cell holders is increased by an amount corresponding to the expansion of the battery cells. In this regard, in this battery module, one protruding portion of the adjacent cell holder is arranged in the other concave portion. In the non-clamped cell holder pair, the insertion length of the protruding portion in the arrangement direction with respect to the concave portion is determined by the expansion of the battery cell. Is greater than or equal to the allowable compression amount per battery cell of the elastic member. Therefore, even when the amount of expansion of the battery cell reaches the allowable compression amount per battery cell and the distance between the first cell holder pair increases by the allowable compression amount per battery cell, the protrusion is inserted into the recess. State is maintained. Therefore, according to this battery module, even when the battery cells expand, the series of the array can be maintained. The “permissible compression amount” means the maximum value of the compression amount of the elastic member when the battery cell expands. In addition, the “permissible compression amount of the elastic member per one battery cell with respect to the expansion of the battery cell” means that, when a plurality of elastic members are arranged, the sum of the allowable compression amounts of the elastic members is divided by the number of arranged battery cells. Means the amount given.

  Further, there is a pair of holding cell holders adjacent to each other with an elastic member between the battery cells, and in the holding cell holder pair, the distance in the arrangement direction from the tip of the protrusion to the bottom surface of the concave portion is arranged between the pair of holding cell holders. May be equal to or more than the allowable compression amount of the elastic member. When the battery cells expand, in the sandwiched cell holder pairs adjacent to each other with the elastic member interposed therebetween, the cell holders approach each other by an amount corresponding to the compression of the elastic member. In this regard, in this battery module, in the sandwiched cell holder pair, the distance in the arrangement direction from the tip of the protrusion to the bottom surface of the concave portion is equal to or more than the allowable compression amount of the elastic member disposed between the sandwiched cell holder pair. . Therefore, even when the elastic members disposed between the sandwiched cell holder pairs are compressed to the allowable compression amount and the cell holders approach each other by the allowable compression amount of the elastic member, the tip of the protruding portion does not contact the bottom surface of the concave portion. As a result, it is possible to avoid that the tip of the protruding portion comes into contact with the bottom surface of the concave portion, and it is possible to suppress the occurrence of a situation in which the cell holder is damaged by receiving a restraining load by the cell holder.

  Further, the cell holder has electrical insulation properties, and the restraining member has a pair of end plates that sandwich the array body and the elastic member in the array direction, and a metal connecting member that connects the pair of end plates to each other. The projection may extend in the arrangement direction so as to cover at least the battery cell side of the connection member. In this case, even when the amount of expansion of the battery cell reaches the allowable compression amount per battery cell, and the distance between the pair of non-clamped cell holders increases by the allowable compression amount per battery cell, the protrusion is inserted into the recess. The battery cell and the connecting member between the cell holders are separated from each other by the protruding portion having electrical insulation. As a result, it is possible to prevent the protruding portion from falling out of the concave portion, and it is possible to prevent a situation in which the metal connecting member is exposed between the cell holders and the insulation between the battery cell and the connecting member cannot be maintained. Can be suppressed.

  Also, the allowable compression amount of the elastic member may be the amount of compression of the elastic member when the constraint load applied to the array and the elastic member by the constraint member increases to a predetermined size due to the expansion of the battery cell. When the battery cell expands, the elastic member is compressed, the elastic repulsion of the elastic member increases, and the constraint load applied to the array and the elastic member by the constraint member increases. If the constraint load becomes excessive, there is a possibility that a problem such as breakage of the constraint member may occur. In this regard, in this battery module, for example, by setting the predetermined size to a value that does not cause such a problem in the battery module, it is possible to suppress the occurrence of a problem in the battery module when the battery cell expands. .

  In the method for manufacturing a battery module according to one aspect of the present invention, an array body in which a plurality of battery cells held by a cell holder are arranged in a predetermined array direction is adjacent to each other without sandwiching an elastic member between the battery cells. An elastic member disposed at both ends in the arrangement direction of the arrangement body and at least one place between the battery cells so that a non-clamped cell holder pair as a cell holder exists, and an assembling step of restricting the arrangement member by pressing the arrangement member in the arrangement direction, One of the adjacent cell holders is provided with a protrusion that projects in the arrangement direction from a surface facing the other of the adjacent cell holders, and the other of the adjacent cell holders is provided with a recess into which the protrusion is inserted, In the non-clamped cell holder pair, the insertion length of the projecting portion into the concave portion in the arrangement direction is equal to the allowable length of the elastic member per battery cell against the expansion of the battery cell. So that the compression amount or more, inserting the protrusion into the recess.

  In the battery module manufactured by this method of manufacturing a battery module, in the non-clamped cell holder pair, the insertion length of the protrusion in the arrangement direction with respect to the concave portion is equal to the allowable compression amount of the elastic member per battery cell with respect to the expansion of the battery cell. That is all. Therefore, even when the amount of expansion of the battery cell reaches the allowable compression amount per battery cell, and the distance between the pair of non-clamped cell holders is widened by the allowable compression amount per battery cell, the protrusion is inserted into the recess. The state is maintained. Therefore, according to this method of manufacturing a battery module, the series of the array can be maintained even when the battery cells expand.

  ADVANTAGE OF THE INVENTION According to this invention, the battery module which can maintain the series of an array body even when a battery cell expands, and the manufacturing method of the battery module which can manufacture such a battery module can be provided.

It is a perspective view of the battery module of a 1st embodiment. FIG. 2 is a schematic sectional view taken along line II-II in FIG. 1. (A) is a perspective view of the cell holder of FIG. 1 as viewed from one side in the arrangement direction, and (b) is a perspective view of the cell holder as viewed from the other side. (A) is a schematic sectional view of the battery module of FIG. 1 before the battery cell expands, and (b) is a schematic sectional view after the battery cell expands. It is a schematic sectional drawing of the battery module of a modification. FIG. 6 is a schematic sectional view taken along line VI-VI in FIG. 5. (A) is a schematic sectional view of a battery module of a modification before expansion of a battery cell, and (b) is a schematic sectional view after expansion of a battery cell. It is a perspective view of a battery module of a 2nd embodiment. FIG. 9 is a schematic sectional view taken along line IX-IX in FIG. 8. 9A is a perspective view of the cell holder of FIG. 8 viewed from one side in the arrangement direction, and FIG. 9B is a perspective view of the cell holder viewed from the other side. 9A is a schematic sectional view of the battery module of FIG. 8 before the battery cell expands, and FIG. 9B is a schematic sectional view after the battery cell expands.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the description of the drawings, the same or corresponding elements have the same reference characters allotted, and overlapping description will be omitted.

[First Embodiment]
The battery module 1 of the first embodiment shown in FIGS. 1 and 2 includes an array 15 including a plurality of battery cells 10 arranged along a predetermined array direction D, and an array of the array 15. An elastic member 20 is provided at one end (the right end in FIG. 2) in the direction D, and a restricting member 30 that presses and restricts the arrangement body 15 and the elastic member 20 in the arrangement direction D. The restraining member 30 includes a pair of end plates 31 sandwiching the array body 15 and the elastic member 20 in the array direction D, and a restraining band (connecting member) 35 connecting the pair of end plates 31 to each other.

  The battery cell 10 is a battery in which an electrode assembly is accommodated in a rectangular box-shaped case. The battery cell 10 is a non-aqueous electrolyte secondary battery such as a lithium ion secondary battery. In this example, seven battery cells 10 are arranged along the arrangement direction D. The battery cell 10 is held by a cell holder 40. The electrode terminals 12 of the adjacent battery cells 10 are electrically connected to each other by a bus bar (not shown), whereby the adjacent battery cells 10 are electrically connected in series.

  As shown in FIG. 2, a rectangular heat transfer plate 13 made of metal is interposed between adjacent battery cells 10. The heat transfer plate 13 is a member for adjusting the temperature of the battery cells 10 and is provided to reduce a temperature difference between adjacent battery cells 10. The array 15 includes the battery cells 10, the cell holders 40, the bus bars, and the heat transfer plates 13. The configuration of the cell holder 40 will be described later.

  The elastic member 20 is formed in a flat plate shape by, for example, a rubber sponge made of urethane. Other examples of the material of the elastic member 3 include, for example, ethylene propylene diene rubber (EPDM), chloroprene rubber, silicon rubber, and the like. As shown in FIG. 2, the elastic member 20 is disposed between the array 15 and the end plate 31. That is, in the first embodiment, each pair of adjacent cell holders 40 is a pair of adjacent non-held cell holders 60 without sandwiching the elastic member 20 between the battery cells 10. In other words, the elastic member 20 is provided so that the non-nipped cell holder pair 60 exists.

  As shown in FIGS. 1 and 2, in this example, a middle plate 25 is arranged between the array 15 and the elastic member 20. The middle plate 25 is formed in a flat plate shape, for example, by a resin. Since the middle plate 25 is interposed between the array 15 and the elastic member 20, the variation in the load acting on the array 15 from the elastic member 20 is suppressed. The middle plate 25 is provided with an arrangement portion 27 in which an extension portion 35a of the restraint band 35 described later is arranged. The arranging portion 27 is constituted by a wall portion having a substantially U-shaped cross section (U-shaped) surrounding the extending portion 35a. In this example, a protruding portion 50 of a cell holder 40 described later is disposed on the disposing portion 27 together with the extending portion 35a.

  The end plate 31 is formed in a plate shape by, for example, metal. The pair of end plates 31 sandwich the array body 15, the elastic member 20, and the middle plate 25 from both sides in the array direction D. The pair of end plates 31 are connected by a plurality (four in this example) of restraint bands 35 extending in the arrangement direction D. Each end plate 31 is provided with a plurality of arrangement portions 33 in which the extension portions 35a of the restraint band 35 are arranged. The arranging portion 33 is configured by a wall having a substantially U-shaped cross section surrounding the extending portion 35a.

  The restraining band 35 is formed in a band shape from a metal such as iron, for example. The restraining band 35 has an extending portion 35a extending along the arrangement direction D, and a fastening portion 35b extending vertically from both ends of the extending portion 35a in the arrangement direction D toward the battery cell 10 side. The extending portion 35a of each restraint band 35 is disposed on each of the arrangement portion 27 of the middle plate 25, the arrangement portion 33 of each end plate 31, and the arrangement portions 49 and 57 of each cell holder 40 described later. The fastening portion 35 b of each restraint band 35 is fastened to the outer surface of each end plate 31 in the arrangement direction D by a fastening member such as a bolt 37. Due to this fastening, a constraint load is applied to the array body 15, the elastic member 20, and the middle plate 25.

  The cell holder 40 is made of, for example, a resin and has electric insulation. As shown in FIG. 3, the cell holder 40 has a frame 42 and a partition 43. Hereinafter, one surface of the cell holder 40 in the arrangement direction D is referred to as a first opposing surface 44, and the other surface is referred to as a second opposing surface 45. In the assembled state, the first opposing surface 44 is an opposing surface to the cell holder 40 adjacent to one side in the arrangement direction D, and the second opposing surface 45 is an opposing surface to the cell holder 40 adjacent to the other side.

  The frame portion 42 has a bottom plate 46 and a pair of side plates 47 standing from both ends of the bottom plate 46. Each of both ends of the bottom plate 46 is provided with a leg 48 projecting in the thickness direction of the bottom plate 46. As shown in FIGS. 2 to 4, each leg 48 is provided with an arrangement portion 49 on which the extension 35 a of the restraining band 35 is arranged. The disposition portion 49 is a concave groove formed so as to be depressed from the bottom surface of the leg portion 48 in the thickness direction of the bottom plate 46. The arranging portion 49 is constituted by a wall having a substantially inverted U-shaped cross section surrounding the extending portion 35a. The wall forms a rectangular columnar arrangement space, and the arrangement space is opened in a direction perpendicular to the arrangement direction D (the thickness direction of the bottom plate 46) in this example.

Each leg 48 is provided with a protruding portion 50 that protrudes in the arrangement direction D from an edge of the arrangement portion 49 on the first facing surface 44. The protruding portion 50 has a wall projecting from the leg 48 so as to be interposed between the battery cell 10 and the extending portion 35a of the restraining band 35, and a pair of uprights standing in the thickness direction of the bottom plate 46 from both ends of the wall. And a wall portion. The projecting portion 50 is formed in a gutter shape as a whole, and has a substantially inverted U-shaped cross section orthogonal to the arrangement direction D. The inner surface of the wall of the protruding portion 50 is continuous with the inner surface of the wall of the disposing portion 49. The extension 35a is arranged inside each projection 50, and the projection 50 covers the battery cell 10 side of the extension 35a.

  The disposing portion 49 has an extending portion 35a of the restraining band 35 and a concave portion 51 on which the protruding portion 50 of the cell holder 40 adjacent to the other side in the arrangement direction D is disposed. The concave portion 51 is provided so as to be concave in the arrangement direction D from the second opposing surface 45 and has a rectangular column shape. In a cross section orthogonal to the arrangement direction D, the cross-sectional shape of the concave portion 51 is larger than the cross-sectional shape of the arrangement portion 49 by at least the thickness of the protruding portion 50. Thereby, both the extending portion 35a and the protruding portion 50 can be arranged in the concave portion 51.

  As shown in FIG. 3, the partition part 43 connects the pair of side plates 47 to each other. A pair of terminal housings 55 are provided on the partition 43. Each terminal accommodating portion 55 has a circular inner wall surrounding the electrode terminal 12. On the partition 43, a pair of bases 56 connected to the terminal housing 55 is provided.

  As shown in FIGS. 2 to 4, each base portion 56 is provided with an arrangement portion 57 in which the extension portion 35 a is arranged. The arranging portion 57 has a shape obtained by inverting the arranging portion 49 in the vertical direction, and is configured by a wall portion having a substantially U-shaped cross section surrounding the extending portion 35a. Each base 56 is provided with a protruding portion 50 so as to protrude from an edge of the arrangement portion 57, and the protruding portion 50 is also provided with an extending portion 35 a. The arranging portion 57 has a concave portion 51, into which the extending portion 35a and the protruding portion 50 are inserted.

  As shown in FIG. 4A, the length L1 in the arrangement direction D of the concave portions 51, that is, the distance in the arrangement direction D from the second opposing surface 45 to the bottom surface of the concave portions 51 is determined by the arrangement of the protrusions 50 with respect to the concave portions 51. It is longer than the insertion length L2 in the direction D. For this reason, in the assembled state, the distal end surface of the protruding portion 50 does not contact the bottom surface of the concave portion 51, and a gap 53 is formed between the distal end surface of the protruding portion 50 and the bottom surface of the concave portion 51. Further, the length of the protrusion 50 in the arrangement direction D from the first facing surface 44 is larger than the insertion length L2. Therefore, in the assembled state, a gap 54 is formed between the first facing surface 44 and the second facing surface 45 of the adjacent cell holders 40.

  As shown in FIG. 3, in the cell holder 40, an accommodation space S is formed by the frame 42 and the partition 43. When the battery cells 10 are accommodated in the accommodation space S, the battery cells 10 are held in the cell holder 40. In the cell holder 40, a rectangular opening 59 is formed by the frame 42 and the lower end surface of the partition 43 in FIG. In the assembled state, heat transfer plate 13 is arranged in opening 59. As a result, as shown in FIGS. 2 and 4, the partition 43 is arranged in the gap formed between the adjacent battery cells 10 by the heat transfer plate 13.

  In this assembled state, no constraint load is applied to the cell holder 40, and the cell holder 40 is slidable along the arrangement direction D with respect to the battery cells 10 and the heat transfer plate 13. Specifically, the cell holder 40 is slidable by the shorter of the length of the gap 53 in the arrangement direction D and the length of the gap 54 in the arrangement direction D. In this example, these lengths are the same. FIGS. 2 and 4 show a state in which the cell holder 40 is arranged at a position where the partitioning portion 43 contacts one surface of the battery cells 10 in the arrangement direction D.

  Next, a case where the battery cells 10 expand in the arrangement direction D will be described with reference to FIG. FIG. 4A is a schematic sectional view of the battery module 1 before the battery cell 10 expands, and FIG. 4B is a schematic sectional view of the battery module 1 after the battery cell 10 expands. FIG. 4B shows a state in which the compression amount of the elastic member 20 has reached the allowable compression amount A1. The mode of expansion of the battery cells 10 includes a case where any one of the plurality of battery cells 10 expands and a case where two or more or all the battery cells 10 expand simultaneously. Hereinafter, a case where all the battery cells 10 expand uniformly will be described as an example. In addition, for convenience of description, dimensions of each member illustrated in the drawings may be different from actual ones.

  In the battery module 1, when each battery cell 10 expands, the elastic member 20 compresses and deforms, thereby allowing each battery cell 10 to expand. Specifically, first, the expanded battery cell 10 is displaced toward the elastic member 20 side. The displaced battery cell 10 presses the adjacent battery cell 10 toward the elastic member 20 via the heat transfer plate 13 and displaces the battery cell 10 toward the elastic member 20. As a result, the battery cell 10 arranged closest to the elastic member 20 in the arrangement direction D is displaced toward the elastic member 20 by an amount obtained by adding the expansion amounts of all the battery cells 10. This battery cell 10 presses the middle plate 25 toward the elastic member 20 side. Thereby, the middle plate 25 moves to the elastic member 20 side. The elastic member 20 is compressed and deformed by being pressed by the middle plate 25. According to the operation described above, when each battery cell 10 expands, the elastic member 20 is compressed and deformed by the total amount of the expansion of the battery cell 10, and the expansion of each battery cell 10 is allowed. At this time, the distance between the adjacent cell holders 40 increases by an amount corresponding to the expansion of each battery cell 10.

  As shown in FIG. 4, the elastic member 20 can be compressed and deformed until the compression amount reaches the allowable compression amount A1. That is, in the battery module 1, the expansion of each battery cell 10 is allowed by an amount obtained by dividing the allowable compression amount A1 by the number of battery cells 10 arranged. Hereinafter, this amount is defined as an allowable compression amount A2 per battery cell of the elastic member 20 with respect to the expansion of the battery cell 10.

  In the battery module 1, the insertion length L2 of the protrusion 50 into the recess 51 is equal to or more than the allowable compression amount A2 per battery cell. Therefore, as shown in FIG. 4B, the expansion amount of each battery cell 10 reaches the allowable compression amount A2 per battery cell (the compression amount of the elastic member 20 reaches the allowable compression amount A1), and the cell holder Even when the distance between the battery cells 40 is increased by the allowable compression amount A2 per battery cell, the state in which the protrusion 50 is inserted into the recess 51 is maintained. Therefore, even when the battery cells 10 expand, the seriality of the array 15 can be maintained.

  Further, in the battery module 1, the projecting portion 50 extends in the arrangement direction D so as to cover the battery cell 10 side of the extending portion 35a of the restraining band 35. Therefore, the amount of expansion of the battery cell 10 per one battery cell is increased. Even when the allowable compression amount A2 is reached and the distance between the cell holders 40 is increased by the allowable compression amount A2 per battery cell, the state in which the protrusion 50 is inserted into the recess 51 is maintained, and the protrusion having electrical insulation properties is maintained. 50 separates the battery cell 10 between the cell holders 40 from the extending portion 35a. As a result, the protrusion 50 can be prevented from falling out of the recess 51, and the metal extension 35a is exposed between the cell holders 40, so that the insulation between the battery cell 10 and the restraint band 35 can be maintained. It is possible to suppress the occurrence of the situation of disappearance.

  Here, the insertion length L2 is determined, for example, as follows. First, the allowable compression amount A1 of the elastic member 20 is calculated. In this example, the allowable compression amount A1 of the elastic member 20 is determined by the elastic member 20 when the constraint load applied to the array 15 and the elastic member 20 by the constraint member 30 increases to a predetermined size due to the expansion of the battery cell 10. The amount of compression. The predetermined size is a value that does not cause a problem in the battery module 1 even when the restraint load increases to the predetermined size. Thereby, when the battery cell 10 expands, it can suppress that a malfunction arises in the battery module 1. An inconvenience that occurs in the battery module 1 when the restraint load becomes excessive includes breakage of the restraint member 30 and the like. The predetermined size is the maximum expansion amount of the battery cell 10 calculated based on the size and characteristics of the battery cell 10, the compression characteristic of the elastic member 20 (for example, the relationship between the compression amount and the elastic repulsion), and the constraint. It can be calculated based on the mechanical strength of the member 30, the distance between the end plates 31 in the arrangement direction D, and the like.

  The allowable compression amount A2 per battery cell is calculated by dividing the allowable compression amount A1 by the number of battery cells 10 arranged. The insertion length L2 is set to a predetermined length equal to or more than the allowable compression amount A2. Here, in the present embodiment, since the cell holder 40 is slidable by a predetermined amount as described above, the predetermined amount may be further added to the insertion length L2. Further, an amount corresponding to the dimensional tolerance may be further added to the insertion length L2.

  The assembly process of the battery module 1 will be described. In the assembling process, an array 15 in which a plurality of battery cells 10 held by the cell holder 40 are arrayed along the array direction D, and an elastic member 20 arranged at one end in the array direction D with respect to the array 15 The restraining member 30 presses and restrains in the arrangement direction D. More specifically, the arrangement body 15 and the elastic member 20 are sandwiched between the pair of end plates 31 in the arrangement direction D, and the pair of end plates 31 are connected by the restraining band 35. At this time, the protrusion 50 is inserted into the recess 51 so that the insertion length L2 is equal to or more than the allowable compression amount A2 per battery cell. Thereby, the battery module 1 is manufactured.

  At this time, in the battery module 1, the cell holders 40 can be positioned by inserting the protruding portions 50 into the concave portions 51, so that the assemblability is enhanced. In addition, as a method of adjusting the insertion length L2, for example, the following method can be considered. For example, a marker or the like serving as a mark is provided in advance at a position separated from the tip by the insertion length L2 in the projecting portion 50, and the projecting portion 50 is inserted into the concave portion 51 so that the mark is not visible in the assembling process. Good.

[Modification of First Embodiment]
The elastic member 20 may be arranged between the battery cells 10 like the battery module 1 </ b> A of the modified example shown in FIGS. 5 to 7. That is, in the battery module 1, each pair of adjacent cell holders 40 is an adjacent non-clamped cell holder pair 60 without sandwiching the elastic member 20 between the battery cells 10. Part of the pair of matching cell holders 40 is a pair of adjacent non-clamping cell holders 60 without sandwiching the elastic member 20 between the battery cells 10, while the rest of the pair of adjacent cell holders 40 (in this example, one pair). ) Are sandwiched cell holder pairs 62 adjacent to each other with the elastic member 20 interposed between the battery cells 10. That is, in the battery module 1A, the elastic member 20 is provided so that both the non-clamped cell holder pair 60 and the clamped cell holder pair 62 exist.

  As shown in FIGS. 6 and 7, in the battery module 1A, one of the sandwiched cell holder pairs 62 is a cell holder 40A having a shape different from that of the cell holder 40. The cell holder 40A is different from the cell holder 40 in having a protrusion 50A instead of the protrusion 50. The protruding length of the protruding portion 50A from the first facing surface 44 in the arrangement direction D is larger than the protruding length of the protruding portion 50. In battery module 1A, middle plate 25 is arranged between battery cell 10 and elastic member 20 held by cell holder 40A.

  As shown in FIG. 7, when the battery cell 10 expands, in the sandwiched cell holder pair 62, the cell holders 40 and 40A approach each other by an amount corresponding to the compression of the elastic member 20. In the battery module 1A, in the sandwiched cell holder pair 62, the distance L3 in the arrangement direction D from the tip of the protrusion 50A to the bottom surface of the recess 51 is equal to the allowable compression amount A1 of the elastic member 20 arranged between the sandwiched cell holder pair 62. That is all. Therefore, even if the elastic members 20 arranged between the sandwiched cell holder pairs 62 are compressed to the allowable compression amount A1 and the cell holders 40 and 40A approach each other by the allowable compression amount A1, the tip of the protruding portion 50A has the bottom surface of the concave portion 51. Do not abut. As a result, it is possible to avoid that the tip of the protruding portion 50A comes into contact with the bottom surface of the concave portion 51, and it is possible to suppress the occurrence of a situation in which the cell holders 40, 40A are damaged by receiving the restraining load by the cell holders 40, 40A.

  In the battery module 1A, as in the battery module 1 of the first embodiment, in the non-clamped cell holder pair 60, the distance between the cell holders 40 is increased by an amount corresponding to the expansion of the battery cells 10; Since the insertion length L2 with respect to 51 is equal to or more than the allowable compression amount A2 per battery cell, the state in which the protrusion 50 is inserted into the recess 51 is maintained, and the seriality of the array 15 can be maintained. .

  In the first embodiment, the arrangement portion 49 does not need to be opened in a direction orthogonal to the arrangement direction D, and may be a through hole that penetrates the leg portion 48 in the arrangement direction D. This is the same for the arrangement units 27, 33, and 57.

[Second embodiment]
Like the battery module 1B of the second embodiment shown in FIGS. 8 to 11, the battery module 1B may include a restraining member 30B including a restraining bolt 38. The restraining member 30B has a pair of end plates 31B sandwiching the array body 15 and the elastic member 20 in the array direction D, and restraining bolts (connecting members) 38 connecting the pair of end plates 31B to each other.

  As shown in FIGS. 9 to 11, in the battery module 1B, the arrangement portion 27B of the middle plate 25B and the arrangement portion 33B of the end plate 31B are configured as through holes through which the restraint bolts 38 are inserted. The arrangement portions 49B and 57B of the cell holder 40B are also formed as through holes through which the restraint bolts 38 are inserted. The arrangement portions 49B and 57B have a columnar concave portion 51B. The diameter of the concave portion 51B is larger than the diameter of the arrangement portions 49B and 57B by at least the thickness in the radial direction of the protrusion 50B.

  The restraint bolt 38 is formed of a metal such as iron, for example. Each restraining bolt 38 is sequentially inserted through the arrangement part 33B of one end plate 31B, the arrangement parts 49B and 57B of each cell holder 40B, the arrangement part 27B of the middle plate 25B, and the arrangement part 33B of the other end plate 31B. Is fastened by a nut 39 outside the end plate 31B. Due to this fastening, a constraint load is applied to the array body 15, the elastic member 20, and the middle plate 25B.

  As shown in FIG. 11, in the battery module 1 </ b> B of the second embodiment, as in the battery module 1 of the first embodiment, in the non-clamped cell holder pair 60, the distance between the cell holders 40 is increased by the amount of the expanded battery cells 10. However, since the insertion length L2 of the protrusion 50 into the recess 51 is equal to or more than the allowable compression amount A2 per battery cell, the state where the protrusion 50 is inserted into the recess 51 is maintained, and the arrangement is performed. The seriality of the body 15 can be maintained.

  The preferred embodiment of the present invention has been described above, but the present invention is not limited to the above embodiment.

  For example, a concavity 51 may be provided on the first facing surface 44 and a protruding portion 50 may be provided on the second facing surface 45, contrary to the above embodiment. Further, both the protrusion 50 and the recess 51 may be provided on each of the first facing surface 44 and the second facing surface 45. For example, a projection 50 is provided on the first facing surface 44 of each leg 48, a recess 51 is provided on the first facing surface 44 of each base 56, and a recess 51 is provided on the second facing surface 45 of each leg 48. A protrusion 50 may be provided on the second facing surface 45 of each base 56.

  One of the adjacent cell holders 40 has the protrusion 50 on both the first opposing surface 44 and the second opposing surface 45, and the other of the adjacent cell holders 40 has both the first opposing surface 44 and the second opposing surface 45. May have a concave portion 51. In this case, since the shapes of the adjacent cell holders 40 can be made different from each other, erroneous assembly is suppressed. Note that such a cell holder 40 and the cell holder 40 of the above-described embodiment may be appropriately combined and used.

  The protrusion 50 need not cover the battery cell 10 side of the connecting member. For example, the protruding portion 50 may protrude from another position on the first facing surface 44 without protruding from the edges of the arrangement portions 49 and 57. In this case, the recess 51 is provided at a position corresponding to the position of the protrusion 50. Further, the protruding portion 50 may have an arbitrary shape such as a flat plate shape or a rod shape. In this case, the concave portion 51 has a shape corresponding to the shape of the projecting portion 50 (the projecting portion 50 can be inserted).

  The elastic members 20 may be arranged at least at both ends in the arrangement direction D of the array body 15 and at least one location between the battery cells 10 so that the non-sandwich cell holder pair 60 exists. D may be arranged on both sides, or may be arranged between one end or both ends of the arrangement body 15 in the arrangement direction D and between the battery cells 10. Further, in the battery module 1A of the modified example, one pair of the sandwiched cell holders 62 is provided, but a plurality of pairs of the sandwiched cell holders 62 may be provided. It is preferable to dispose the elastic members 20 at a plurality of positions as in these cases, since the expansion of the battery cell 10 can be further allowed. When a plurality of elastic members 20 are arranged, the allowable compression amount A2 per battery cell of the elastic member 20 with respect to the expansion of the battery cell 10 is determined by adding the total allowable compression amount A1 of each elastic member 20 to the battery cell 10. The amount may be divided by the number of arrangements.

  The cell holders 40, 40A, and 40B only need to have an insulating property at least at a contact position with the battery cell 10, the heat transfer plate 13, and the connecting member (the restraint band 35 or the restraint bolt 38), and a part thereof is made of metal. It may be made of. However, it is preferable that the entirety is made of resin from the viewpoint of easiness of molding, and it is preferable to include metal in that rigidity can be improved. The middle plate 25 may be omitted.

1, 1A, 1B: battery module, 10: battery cell, 15: array, 20: elastic member, 25: middle plate, 30, 30B: restraining member, 31, 31B: end plate, 35: restraining band (connecting member) ), 38 ... restraint bolts (connecting members), 40, 40A, 40B ... cell holders, 50 ... protrusions, 51 ... recesses, 60 ... non-clamping cell holder pairs, 62 ... clamping cell holder pairs, D ... arrangement direction.

Claims (5)

An array body including a plurality of battery cells held by the cell holder and arranged along a predetermined arrangement direction,
The elastic member disposed at at least one position between both ends in the arrangement direction of the array and the battery cells, so that adjacent non-clamped cell holder pairs exist without sandwiching the elastic member between the battery cells.
A restraining member for restraining the array body and the elastic member by pressing in the array direction,
One of the adjacent cell holders is provided with a protrusion that projects in the arrangement direction from a surface facing the other of the adjacent cell holders, and the other of the adjacent cell holders has a recess in which the protrusion is disposed. Provided,
In the non-clamped cell holder pair, the insertion length of the protruding portion in the arrangement direction with respect to the concave portion is equal to or more than an allowable compression amount per battery cell of the elastic member with respect to expansion of the battery cell ,
Even when the amount of expansion of the battery cell reaches the allowable compression amount per battery cell and the distance between the pair of non-clamped cell holders is widened by the allowable compression amount per battery cell, the protruding portion is the concave portion. A battery module that is kept inserted in the battery module. There is a sandwiched cell holder pair adjacent to each other with the elastic member interposed between the battery cells,
In the holding cell holder pair, the distance in the arrangement direction from the tip of the protruding portion to the bottom surface of the concave portion is equal to or larger than the allowable compression amount of the elastic member disposed between the holding cell holder pair. The battery module according to claim 1. The cell holder has an electrical insulating property,
The restraint member has a pair of end plates that sandwich the arrangement body and the elastic member in the arrangement direction, and a metal connection member that connects the pair of end plates to each other,
The battery module according to claim 1, wherein the projecting portion extends in the arrangement direction so as to cover at least the battery cell side of the connection member.   The allowable compression amount of the elastic member is a compression amount of the elastic member when a restraint load applied to the array body and the elastic member by the restraint member increases to a predetermined size due to expansion of the battery cell. The battery module according to any one of claims 1 to 3. An array body in which a plurality of battery cells held by a cell holder are arrayed along a predetermined array direction, and the array body so that there is a pair of non-sandwich cell holders adjacent to each other without sandwiching an elastic member between the battery cells. An elastic member arranged at both ends in the arrangement direction and at least one place between the battery cells, and an assembly step of restricting the arrangement member by pressing the arrangement member in the arrangement direction;
One of the adjacent cell holders is provided with a protrusion that projects in the arrangement direction from a surface facing the other of the adjacent cell holders, and the other of the adjacent cell holders has a recess into which the protrusion is inserted. Provided,
In the assembly process,
Wherein in the non-pinching cell holder pair, the arrangement direction of the insertion length to the recess of the projecting portion is Ri Do a more tolerable amount of compression per battery cell of said elastic member with respect to expansion of the battery cells, and,
Even when the amount of expansion of the battery cell reaches the allowable compression amount per battery cell and the distance between the pair of non-clamped cell holders is widened by the allowable compression amount per battery cell, the protruding portion is the concave portion. A method for manufacturing a battery module, comprising: inserting the protruding portion into the recess so that a state of being inserted into the battery module is maintained .

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