JP2017174741A - Battery module and cell holder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a battery module having a structure that can shorten the time required for manufacturing the battery module, and to provide a cell holder.SOLUTION: A battery module 10 includes: multiple arranged battery cells 20; a cell holder 30 holding the multiple battery cells 20, respectively, and provided with a through hole 38 penetrating in the arrangement direction of the multiple battery cells 20; and a bolt B extending in the arrangement direction of the multiple battery cells 20, and penetrating the through hole 38. The through hole 38 provided in at least one cell holder 30 has such a taper shape as the diameter decreases toward a tip 52 of the bolt B. The tip 52 of the bolt B has a chamfered portion 53.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a battery module and a cell holder.

  A battery module including a plurality of cell holders connected by a connecting member is known (see Patent Document 1). The connecting member is provided with a through hole for inserting a connecting rod. This through hole has a tapered shape.

JP 2013-8479 A

  In the battery module, when the connecting rod is inserted into the through hole, the corner portion at the tip of the connecting rod may be caught on the inner surface of the through hole. If the connecting rod is inserted into the through hole while moving the connecting rod so that the corner of the tip of the connecting rod is not caught on the inner surface of the through hole, it takes time to insert the connecting rod.

  Further, in the battery module described above, in order to determine the direction of the cell holder (the direction of the tapered shape of the through hole), it is necessary to determine the difference by observing the size of the through hole. It is difficult to distinguish with.

  Therefore, in the structure of the battery module, it is difficult to shorten the time required for manufacturing the battery module.

  An object of one aspect of the present invention is to provide a battery module and a cell holder having a structure that can shorten the time required for manufacturing the battery module.

  A battery module according to an aspect of the present invention includes a plurality of arranged battery cells, a cell holder that holds each of the plurality of battery cells, and is provided with a through-hole penetrating in the arrangement direction of the plurality of battery cells. A plurality of bolts extending in the arrangement direction of the plurality of battery cells and penetrating the through-holes, and the diameter of the through-holes provided in at least one of the cell holders toward the tip of the bolts The tip of the bolt has a chamfered portion.

  In this battery module, since the through hole provided in at least one cell holder has a tapered shape and the tip of the bolt has a chamfered portion, the tip of the bolt is inserted when the bolt is inserted into the through hole. Is difficult to get caught on the inner surface of the through hole. Therefore, the bolt can be smoothly inserted into the through hole. Therefore, the time required for manufacturing the battery module can be shortened.

  The cell holder may include a protrusion provided at one end of the through hole and a hole provided at the other end of the through hole and having a shape that can be fitted to the protrusion.

  In this case, the direction of the cell holder can be determined in a short time by observing the protrusion or the hole. Therefore, the direction in which the bolt is inserted can be determined in a short time.

  The battery module includes a first end plate and a second end plate that apply a restraining load to the plurality of battery cells in an arrangement direction of the plurality of battery cells, and a space between the second end plate and the plurality of battery cells. And an elastic member disposed on the tip of the bolt, and the second end plate is located between the nut and the elastic member, and the second end plate The end plate is provided with a through hole for allowing the bolt to pass therethrough, and the through hole of the second end plate has a tapered shape so that the diameter decreases toward the tip of the bolt. You may have.

  The bolt is inserted into the through hole of the second end plate located on the nut side after passing through the through hole of the cell holder holding the battery cell. Furthermore, the second end plate is located at a location away from the plurality of battery cells by the elastic member. Therefore, normally, when a bolt is inserted into the through hole of the second end plate, it is difficult to insert the bolt smoothly compared to the case of inserting the bolt into the through hole of the cell holder. Even in such a case, since the tip of the bolt has a chamfered portion and the through hole of the second end plate has a tapered shape, the bolt can be smoothly inserted into the through hole of the second end plate. Can be inserted.

  The battery module further includes a middle plate disposed between the plurality of battery cells and the elastic member, and the middle plate is provided with a through hole for allowing the bolt to pass therethrough. The through hole of the plate may have a tapered shape such that the diameter decreases as it goes toward the tip of the bolt.

  In this case, the bolt can be smoothly inserted into the through hole of the middle plate.

  The number of the plurality of battery cells may be three or more.

  In this case, there are many places (steps between the inner surface of the through hole and the through hole) where the tip of the bolt may be caught. Even in such a case, the bolt can be smoothly inserted into the through hole of the cell holder.

  The through hole provided in the cell holder located farthest from the tip of the bolt may have the tapered shape.

  The bolt is inserted from the through hole of the cell holder located farthest from the tip of the bolt when passing through the through holes of the plurality of cell holders. For this reason, when inserting the tip of the bolt into the through hole of the cell holder, it takes time to align the tip of the bolt with the through hole. However, if the through hole of the cell holder has a tapered shape, the bolt can be smoothly inserted into the through hole.

  A cell holder according to another aspect of the present invention is a cell holder for holding a battery cell, and includes a protrusion and a hole having a shape that can be fitted to the protrusion, from the hole. A through hole is provided for penetrating to the protrusion and penetrating the bolt, and the through hole has a tapered shape so that the diameter decreases from the hole toward the protrusion. Yes.

  In this cell holder, the direction of the cell holder (the direction of the tapered shape of the through hole) can be determined in a short time by observing the protrusion or the hole. Therefore, the direction in which the bolt should be inserted can be determined in a short time. Therefore, the time required for manufacturing the battery module can be shortened.

  According to one aspect of the present invention, it is possible to provide a battery module and a cell holder having a structure that can shorten the time required for manufacturing the battery module.

It is a perspective view which shows typically the battery module which concerns on 1st Embodiment. It is a disassembled perspective view which shows typically the cell holder, battery cell, and heat-transfer plate which are contained in the battery module of FIG. It is a fragmentary sectional view of the battery module along the III-III line of FIG. It is a top view which shows the modification of a volt | bolt. It is a figure which shows an example of the process in which a volt | bolt is inserted in the through-hole of a cell holder. It is a fragmentary sectional view showing typically the battery module concerning a 2nd embodiment. It is a fragmentary sectional view showing typically the battery module concerning a 3rd embodiment.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the description of the drawings, the same reference numerals are used for the same or equivalent elements, and redundant descriptions are omitted. In the drawing, an XYZ orthogonal coordinate system is shown as necessary.

(First embodiment)
FIG. 1 is a perspective view schematically showing the battery module according to the first embodiment. FIG. 2 is an exploded perspective view schematically showing a cell holder, a battery cell, and a heat transfer plate included in the battery module of FIG. FIG. 3 is a partial cross-sectional view of the battery module taken along line III-III in FIG. 1. The battery module 10 shown in FIGS. 1 to 3 is housed in, for example, a housing and can be used as a battery for an industrial vehicle such as a forklift.

  The battery module 10 shown in FIGS. 1 to 3 includes a plurality of battery cells 20 arranged in the Y-axis direction, and a cell holder 30 that holds each of the plurality of battery cells 20. The battery module 10 may include a first end plate 14 and a second end plate 15 that apply a restraining load to the plurality of battery cells 20 in the arrangement direction (Y-axis direction) of the plurality of battery cells 20. In this case, the plurality of battery cells 20 are located between the end plates 14 and 15. A bracket 16 is provided on each of the end plates 14 and 15. For example, the battery modules 10 are fixed to the casing by fixing the brackets 16 and 16 to the casing with fastening bolts. Each end plate 14, 15 may be integral with the bracket 16. The end plates 14 and 15 and the bracket 16 are, for example, metal members.

  The battery module 10 includes a bolt B that extends in the arrangement direction (Y-axis direction) of the plurality of battery cells 20. In the present embodiment, the battery module 10 includes a plurality (four in the example of FIG. 1) of bolts B. The length of each bolt B is, for example, 200 mm or more. As shown in FIGS. 1 and 3, each bolt B is inserted from the first end plate 14 toward the second end plate 15, and at the position where the second end plate 15 is inserted. N can be screwed onto. By fastening the bolt B and the nut N, a restraining load is applied to the end plates 14 and 15 and the plurality of battery cells 20.

  The number of battery cells 20 may be 3 or more, 5 or more, 10 or more, or 20 or less (in the example of FIG. 1). The number of battery cells 20 is seven).

  The battery cell 20 is a nonaqueous electrolyte secondary battery such as a lithium ion secondary battery. The battery cell 20 includes, for example, a hollow case having a substantially rectangular parallelepiped shape and an electrode assembly accommodated in the case. The case is made of a metal such as aluminum. For example, an organic solvent-based or non-aqueous electrolyte is injected into the case. The electrode assembly includes a positive electrode, a negative electrode, and a separator disposed between the positive electrode and the negative electrode. In the electrode assembly, for example, a positive electrode is accommodated in a bag-shaped separator, and a bag-shaped separator and a negative electrode in which the positive electrode is accommodated are alternately stacked.

  As shown in FIG. 2, the cell holder 30 includes a bottom surface portion 31, a first side surface portion 32, a second side surface portion 33, a partition portion 34, and a plurality of (four in the example of FIG. 2) pillars. Part 37 may be provided. The cell holder 30 is an integrally molded resin member, for example.

  The bottom surface portion 31 is formed in a rectangular flat plate shape and faces the bottom surface of the battery cell 20. The first side surface portion 32 and the second side surface portion 33 are connected to both ends in the longitudinal direction (X-axis direction) of the bottom surface portion 31 and extend in the Z-axis direction. The first side surface portion 32 and the second side surface portion 33 are formed in a rectangular flat plate shape, and respectively cover a pair of side surfaces (side surfaces extending in the Y-axis direction and the Z-axis direction) of the battery cell 20. The partition part 34 is formed in a rectangular flat plate shape. The partition part 34 includes a first end part 32a (an end part opposite to the end part connected to the bottom part 31) in the longitudinal direction (Z-axis direction) of the first side face part 32, and a second side face. The first end portion 33a in the longitudinal direction (Z-axis direction) of the portion 33 (the end portion opposite to the end portion connected to the bottom surface portion 31) is connected. The partition portion 34 is arranged such that the thickness direction thereof coincides with the arrangement direction (Y-axis direction) of the battery cells 20 and the longitudinal direction (X-axis direction) thereof coincides with the longitudinal direction of the bottom surface portion 31. A region surrounded by the bottom surface portion 31, the first side surface portion 32, and the second side surface portion 33 is a housing portion S in which the battery cell 20 is housed.

  The first end portions 32a and 33a in the longitudinal direction (Z-axis direction) of the first side surface portion 32 and the second side surface portion 33 are provided with rectangular flat plate-shaped protrusions 35 extending in the Z-axis direction. . The second end portions 32c and 33c in the longitudinal direction (Z-axis direction) of the first side surface portion 32 and the second side surface portion 33 are respectively provided with column portions 37 and 37 extending in the Y-axis direction. Yes. The partition portion 34 is provided with column portions 37 and 37 arranged in the longitudinal direction (X-axis direction) of the partition portion 34. Each column portion 37 extends in the Y-axis direction.

  The cell holder 30 is provided with a through hole 38 penetrating in the arrangement direction (Y-axis direction) of the plurality of battery cells 20. In the present embodiment, a plurality of through holes 38 are provided in the plurality of column portions 37, respectively. The through hole 38 is a hole for allowing the bolt B to pass therethrough. The through hole 38 extends, for example, linearly in the Y-axis direction. The XZ cross section of the through hole 38 is circular, for example.

  Each column part 37 is provided with the projection part 37a and the hole part 37b which has a shape which can be fitted to the projection part 37a. The protrusion 37a does not fit into the hole 37b in one cell holder 30, but the protrusion 37a of one cell holder 30 fits into the hole 37b of the other cell holder 30 between two adjacent cell holders 30. (See FIG. 3). The through hole 38 penetrates from the hole 37b to the protrusion 37a. The through hole 38 extends from the opening surface of the hole portion 37b to the top surface of the projection portion 37a. The protrusion 37 a is provided at one end of the through hole 38, and the hole 37 b is provided at the other end of the through hole 38. The protrusion 37a is a cylindrical portion having an annular inner surface and an outer surface. The hole 37b has an inner surface that can be fitted to the outer surface of the protrusion 37a. The inner surface of the protrusion 37 a and the inner surface of the hole 37 b constitute a part of the inner surface of the through hole 38.

  The battery module 10 may include a heat transfer plate 41 disposed between adjacent battery cells 20. The heat transfer plate 41 includes a first plate-like portion 42 positioned between adjacent battery cells 20 and a second plate-like portion 43 that intersects the first plate-like portion 42. The first plate-like portion 42 may be in direct contact with the battery cell 20, or may be connected to the battery cell 20 via another heat transfer member. The second plate-like portion 43 covers the outer surface of the second side surface portion 33. The heat transfer plate 41 is, for example, a metal member. The heat generated in the battery cell 20 is transmitted from the first plate-like portion 42 toward the second plate-like portion 43, and is transmitted from the second plate-like portion 43 to the housing to which the battery module 10 is fixed. Is done. When the battery module 10 does not include the heat transfer plate 41, for example, heat can be radiated by flowing a refrigerant between the battery cells 20. For example, by providing a groove in the cell holder 30, a refrigerant flow path is formed.

  As shown in FIG. 3, the bolt B is inserted into the through hole 14 a of the end plate 14, the through hole 38 of the cell holder 30, and the through hole 15 a of the end plate 15. When the end plate 15 is adjacent to the cell holder 30, a hole 15 b that can be fitted to the protrusion 37 a of the cell holder 30 may be provided at the end of the through hole 15 a on the battery cell 20 side. The head 51 of the bolt B is located on the end plate 14 side. The tip 52 of the bolt B is located on the end plate 15 side. A nut N is located at the tip 52 of the bolt B.

  The tip 52 of the bolt B has a chamfered portion 53. The chamfered portion 53 is, for example, a C chamfered portion (planar portion). As shown in FIG. 4, the chamfered portion 53 may be an R chamfered portion (curved surface portion). The R chamfered portion is less likely to be caught on the inner surface of the through hole 38 than the C chamfered portion. The chamfered portion 53 is not limited to the chamfered portion formed by chamfering the corner portion of the bolt B having the corner portion at the tip 52. For example, the bolt B which does not have a corner | angular part in the front-end | tip 52 by originally forming the chamfer 53 of the front-end | tip 52 in planar shape or curved surface may be used. The through holes 14 a, 15 a, and 38 have a tapered shape so that the diameter becomes smaller toward the tip 52 of the bolt B. The inner surface of the protrusion 37a and the inner surface of the hole 37b also have a tapered shape so that the diameter decreases toward the tip 52 of the bolt B. The diameters of the through holes 14a, 15a, 38 monotonously decrease from one end of the through holes 14a, 15a, 38 to the other end toward the tip 52 of the bolt B, respectively. The outer surface of the protrusion 37a and the inner surface of the hole 37b may have the same taper shape.

  FIG. 5 is a diagram illustrating an example of a process in which the bolt is inserted into the through hole of the cell holder. In FIG. 5, the end plate 14 is omitted. As shown in FIG. 5, the bolt B is inserted from the hole 37 b of the cell holder 30 toward the protrusion 37 a. When the chamfered portion 53 is a C chamfered portion, the smaller one of the angles formed by the C chamfered portion and the Y axis direction is θ1, and the smaller one of the angles formed by the inner surface of the through hole 38 and the Y axis direction is θ2. , Θ1 ≧ θ2 may be satisfied. In this case, the tip 52 of the bolt B is not easily caught by the inner surface of the through hole 38 and the chamfered portion 53 can be easily formed. If the outlet diameter of the through hole 38 (the diameter of the through hole 38 at the top surface of the protrusion 37a) is D1, and the inlet diameter (the diameter of the through hole 38 at the opening surface of the hole 37b) is D2, D2-D1 ≧ (projection Clearance between the portion 37a and the hole portion 37b) + (difference between the inner diameter and the outer diameter of the protruding portion 37a). The clearance includes processing tolerances of the protrusion 37a and the hole 37b.

  In the battery module 10 of the first embodiment, the through hole 38 of the cell holder 30 has a tapered shape, and the tip 52 of the bolt B has a chamfered portion 53, so the bolt B is inserted into the through hole 38. At this time, the tip 52 of the bolt B is not easily caught on the inner surface of the through hole 38. Therefore, the bolt B can be smoothly inserted into the through hole 38. Therefore, the time required for manufacturing the battery module 10 can be shortened.

  Further, when the tip of the bolt does not have a chamfered portion, if the corner of the tip of the bolt is caught on the inner surface of the through hole 38, the cell holder 30 may be displaced due to an impact. In the battery module 10, such a displacement of the cell holder 30 can be suppressed.

  When the cell holder 30 has the protrusion 37a and the hole 37b, the direction of the cell holder 30 (the direction of the tapered shape of the through hole 38) is determined in a short time by observing the protrusion 37a or the hole 37b. be able to. That is, it can be understood that the bolt B may be inserted from the hole 37b. Therefore, the direction in which the bolt B is inserted can be determined in a short time.

  Moreover, since the protrusion 37a fits into the hole 37b, the positional deviation between the adjacent cell holders 30 can be suppressed, so that the step between the adjacent through holes 38 can be reduced. As a result, the bolt B can be smoothly inserted through the plurality of through holes 38.

  When the number of the battery cells 20 is three or more, there are many places (steps between the inner surface of the through hole 38 and the through hole 38) where the tip 52 of the bolt B may be caught. Even in such a case, the bolt B can be smoothly inserted into the through hole 38 of the cell holder 30.

  In the cell holder 30 of the first embodiment, the direction of the cell holder 30 (the direction of the tapered shape of the through hole 38) can be determined in a short time by observing the protrusions 37a or the holes 37b. Therefore, the direction in which the bolt B should be inserted can be determined in a short time. Therefore, the time required for manufacturing the battery module 10 can be shortened.

  When the bolt B passes through the through holes 38 of the plurality of cell holders 30, the bolt B is inserted from the through hole 38 of the cell holder 30 located farthest from the tip 52 of the bolt B (ie, the cell holder 30 on the head 51 side of the bolt B). Is done. For this reason, when the tip 52 of the bolt B is inserted into the through hole 38 of the cell holder 30, it takes time to align the tip 52 of the bolt B and the through hole 38. However, if the through hole 38 of the cell holder 30 has a tapered shape such that the diameter decreases toward the tip 52 of the bolt B, the bolt B can be smoothly inserted into the through hole 38.

(Second Embodiment)
FIG. 6 is a partial cross-sectional view schematically showing the battery module according to the second embodiment. The battery module 110 shown in FIG. 6 has the same configuration as that of the battery module 10 of the first embodiment, except that each column portion 37 of each cell holder 30 does not have the protruding portion 37a and the hole portion 37b. In the battery module 110, since the cell holder 30 does not have the protrusion 37a, the hole 15b that can be fitted to the protrusion 37a of the cell holder 30 is not provided at the end of the through hole 15a on the battery cell 20 side. .

  In the second embodiment, if the outlet diameter of the through hole 38 is D1 and the inlet diameter is D2, D2−D1 ≧ (tolerance of the position of the through hole 38 from the reference position). The reference position may be the bottom surface of the column portion 37 positioned on the bottom surface portion 31 of the cell holder 30, or the outer surface of the second side surface portion 33 positioned on the bracket 16 side (or the second plate of the heat transfer plate 41). It may be the outer surface of the shaped part 43). The position of the through hole 38 is, for example, the center position of the through hole 38.

  Also in the second embodiment, an operational effect based on the same configuration as in the first embodiment can be obtained.

(Third embodiment)
FIG. 7 is a partial cross-sectional view schematically showing the battery module according to the third embodiment. The battery module 210 shown in FIG. 7 has the same configuration as the battery module 10 of the first embodiment except that the battery module 210 further includes an elastic member 60 and a middle plate 70. In the battery module 210, since the end plate 15 is not adjacent to the cell holder 30, the hole 15b that can be fitted to the protrusion 37a of the cell holder 30 is not provided at the end of the through hole 15a on the battery cell 20 side. .

  The elastic member 60 is disposed between the end plate 15 and the battery cell 20. The elastic member 60 can absorb fluctuations in the arrangement direction of the battery cells 20. The elastic member 60 is a member used for the purpose of preventing the battery cell 20 and the end plates 14 and 15 from being damaged by a restraining load when the battery cell 20 is expanded. The elastic member 60 is formed in a rectangular plate shape by, for example, urethane rubber sponge, and is disposed between the battery cell 20 on one end side in the arrangement direction and the end plate 15. Examples of other forming materials of the elastic member 60 include ethylene propylene diene rubber (EPDM), chloroprene rubber, and silicone rubber. The elastic member 60 is not limited to rubber and may be a spring material or the like.

  The middle plate 70 is disposed between the battery cell 20 and the elastic member 60. The middle plate 70 is a resin member, for example. The middle plate 70 suppresses variation in the load applied from the elastic member 60 to the battery cell 20. The planar shape of the middle plate 70 viewed from the arrangement direction of the battery cells 20 is, for example, a rectangle and the same shape as the end plates 14 and 15. The middle plate 70 is provided with a through hole 70a for allowing the bolt B to pass therethrough. The through hole 70 a has a tapered shape so that the diameter decreases as it goes toward the tip 52 of the bolt B. In the battery module 210, since the middle plate 70 is adjacent to the cell holder 30, a hole 70b that can be fitted to the protrusion 37a of the cell holder 30 is provided at the end of the through hole 70a on the battery cell 20 side. . The through hole 70 a is provided outside the contact area with the elastic member 60 on the surface of the middle plate 70. The middle plate 70 is slidable in the arrangement direction of the battery cells 20. For example, the middle plate 70 slides toward the elastic member 60 as the battery cell 20 expands.

  Also in the third embodiment, an operational effect based on the same configuration as in the first embodiment can be obtained. Further, the end plate 15 is positioned away from the battery cell 20 by the elastic member 60. Therefore, normally, when a bolt is inserted into the through hole 15 a of the end plate 15, it is difficult to insert the bolt smoothly compared to a case where the bolt is inserted into the through hole 38 of the cell holder 30. Even in such a case, since the tip 52 of the bolt B has the chamfered portion 53 and the through hole 15a of the end plate 15 has a tapered shape, the bolt B is inserted into the through hole 15a of the end plate 15. Can be inserted smoothly. Similarly, the bolt B can be smoothly inserted into the through hole 70 a of the middle plate 70.

  As mentioned above, although preferred embodiment of this invention was described in detail, this invention is not limited to the said embodiment.

  For example, the battery module 210 may not include the middle plate 70 in the third embodiment. In this case, the elastic member 60 is adjacent to the cell holder 30.

  In the second embodiment, the battery module 110 may further include an elastic member 60 disposed between the end plate 15 and the battery cell 20. Further, the battery module 110 may further include a middle plate 70 disposed between the battery cell 20 and the elastic member 60 in addition to the elastic member 60. In this case, the same effect as the third embodiment can be obtained.

  In each of the first to third embodiments, the through hole 38 provided in at least one cell holder 30 among the plurality of cell holders 30 is tapered so that the diameter decreases toward the tip 52 of the bolt B. You may have a shape. In this case, the through holes 38 of the remaining cell holders 30 do not have the tapered shape. For example, only the through hole 38 of the cell holder 30 located farthest from the tip 52 of the bolt B (that is, the cell holder 30 on the head 51 side of the bolt B) has a diameter that decreases toward the tip 52 of the bolt B. May have a tapered shape.

  DESCRIPTION OF SYMBOLS 10,110,210 ... Battery module, 14a, 15a, 38, 70a ... Through-hole, 14 ... 1st end plate, 15 ... 2nd end plate, 20 ... Battery cell, 30 ... Cell holder, 37a ... Projection part, 37b ... hole, 52 ... tip, 53 ... chamfered portion, 60 ... elastic member, 70 ... middle plate, B ... bolt, N ... nut.

Claims (7)

A plurality of battery cells arranged;
A cell holder that holds each of the plurality of battery cells and is provided with a through-hole penetrating in the arrangement direction of the plurality of battery cells;
A bolt extending in the arrangement direction of the plurality of battery cells, and penetrating the through hole;
With
The through-hole provided in at least one of the cell holders has a tapered shape so that the diameter decreases toward the tip of the bolt;
The battery module, wherein the tip of the bolt has a chamfered portion.   The cell holder has a protrusion provided at one end of the through hole and a hole provided at the other end of the through hole and having a shape that can be fitted into the protrusion. The battery module described in 1. First and second end plates for applying a restraining load to the plurality of battery cells in the arrangement direction of the plurality of battery cells;
An elastic member disposed between the second end plate and the plurality of battery cells;
A nut positioned at the tip of the bolt;
Further comprising
The second end plate is located between the nut and the elastic member;
The second end plate is provided with a through hole for allowing the bolt to pass through,
3. The battery module according to claim 1, wherein the through hole of the second end plate has a tapered shape such that a diameter thereof decreases toward a tip of the bolt. A middle plate disposed between the plurality of battery cells and the elastic member;
The middle plate is provided with a through-hole for penetrating the bolt,
4. The battery module according to claim 3, wherein the through hole of the middle plate has a tapered shape such that a diameter thereof decreases toward a tip of the bolt.   The battery module according to claim 1, wherein the number of the plurality of battery cells is three or more.   The battery module according to claim 1, wherein the through hole provided in the cell holder located farthest from the tip of the bolt has the tapered shape. A cell holder for holding a battery cell,
A protrusion,
A hole having a shape that can be fitted to the protrusion, and
With
A through hole for penetrating the bolt from the hole to the projection is provided,
The cell holder, wherein the through-hole has a tapered shape so that the diameter decreases from the hole toward the protrusion.

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