JP2017123308A - Battery module - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a battery module which can suppress a reduction in heat dissipation efficiency due to changes over time.SOLUTION: A battery module 21 is fitted to a housing 11 via a heat conduction member 51 and comprises: an array body 28 made up of a plurality of battery cells 23 aligned in one direction D, and a plurality of heat transfer plates 41 arranged to be into contact with a principal surface 24c, which is a surface intersecting the one direction of the battery cells; and a bolt B and a nut N which bind the array body while applying pressure in the one direction. The heat transfer plates each comprise: a first body part 42 which comes into contact with the principal surface; and a second body part 43 which intersects the principal surface from one end side of the first body part and comes into contact with the heat conduction member. The first body part and the second body part intersect each other at an acute angle.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a battery module.

  A battery pack in which a battery module in which a plurality of battery cells held in a battery holder are arranged is attached to a housing or the like is known. Patent Document 1 discloses a battery module that can improve heat dissipation by attaching a heat transfer plate to a battery holder and bringing the heat transfer plate into contact with a housing via a heat conductive member. In this battery module, an elastic member is disposed at an end in the arrangement direction of a plurality of battery cells arranged, and the plurality of battery cells and the elastic member are integrally restrained in a state of being pressed in the arrangement direction. .

JP 2015-156303 A

  However, in the conventional battery module, after being attached to the casing as a battery pack, the battery cell may be displaced in a direction crossing the mounting surface of the casing due to a reaction force from the heat conducting member. In this case, the heat transfer plate may not come into contact with the heat conducting member with time, and the heat radiation efficiency may be reduced.

  Therefore, an object of the present invention is to provide a battery module that can suppress a decrease in heat dissipation efficiency accompanying a change with time.

  The battery module of the present invention is a battery module that is attached to a housing via a heat conducting member, and has a plurality of battery cells arranged in one direction and a main surface that intersects the battery cell in one direction. A plurality of heat transfer plates arranged so as to be in contact with each other and arranged in one direction; and a restraining portion that restrains the array in a state of being pressed in one direction. A first main body portion that contacts the main surface, and a second main body portion that is bent in a direction intersecting the main surface from one end side of the first main body portion and that contacts the heat conducting member, and the first main body portion, It intersects the second body part at an acute angle.

  According to the battery module having this configuration, since the first main body and the second main body intersect at an acute angle, the heat transfer plate is thermally conductive at the portion where the first main body and the second main body intersect. Contact the member. As a result, the contact area between the heat transfer plate and the heat conducting member is smaller than when the second main body part is in contact with the heat conducting member, so that the reaction force that the heat conducting plate receives from the heat conducting member is small. Become. For this reason, the shift | offset | difference of the battery cell to the direction which cross | intersects the attachment surface of a housing | casing is suppressed, and possibility that a heat-transfer plate and a heat conductive member will not contact can be made small. As a result, it is possible to suppress a decrease in heat dissipation efficiency due to a change with time.

  In the battery module of the present invention, the first main body portion side of the second main body portion may be formed with a curved portion that bends smoothly from one end side of the first main body portion.

  In the battery module having this configuration, the curved portion of the heat transfer plate comes into contact with the heat conducting member. Thereby, the damage of a heat conductive member can be suppressed compared with the part where the angled part contacts a heat conductive member.

  In the battery module of the present invention, the crossing angle between the first main body portion and the second main body portion may be larger as the heat transfer plate is in contact with the battery cell located at the center of the array in one direction.

  In the battery module configured to restrain the array body in a state where the array body is pressed in one direction by the restraint section, the restraint force by the restraint section is stronger in the battery cells located at both ends of the array body, and the heat transfer plate is separated from the heat conduction member. Receive strong reaction force. In the battery module having this configuration, the heat transfer plate that receives the reaction force from the heat conductive member more strongly, that is, the heat transfer plate that contacts the battery cells disposed at both ends of the array body, the portion that contacts the heat conductive member. Is formed such that the bending angle is small, and the reaction force received from the heat conducting member is small. Therefore, the influence of the reaction force received from the heat conducting member can be reduced. As a result, the shift of the battery cell in the direction intersecting the mounting surface of the housing can be further suppressed.

  The battery module of the present invention further includes an elastic member disposed at one end of the array body, and the restraining portion restrains the array body and the elastic member in a state of being pressed in one direction, The main body may be bent from the first main body in the direction in which the elastic member is disposed.

  In the battery module having this configuration, even when the heat transfer plate moves due to the expansion of the battery cells, the heat transfer plate moves in the bending direction, and therefore, damage to the heat conducting member can be suppressed.

  According to the present invention, it is possible to suppress a decrease in heat dissipation efficiency accompanying a change with time.

It is a perspective view which shows the battery pack containing the battery module in one Embodiment. It is a side view which shows the battery module in one Embodiment. It is a disassembled perspective view which shows the battery cell of FIG. 2, a battery holder, and a heat-transfer plate. It is a side view which shows the arrangement | sequence state of the battery cell of FIG. 2, a battery holder, and a heat-transfer plate. (A) is the side view which showed one battery cell, the battery holder, and the heat-transfer plate, (B) is the side view which expanded and showed the curved part of the heat-transfer plate. It is the side view which showed the battery module of FIG. 2 attached to the side wall by which the heat conductive member is arrange | positioned. It is a side view which shows the state in which the battery module of FIG. 2 was attached to the side wall. It is a side view which shows the heat-transfer plate which moves by expansion | swelling of a battery cell.

  Hereinafter, a battery pack 10 including a battery module 21 according to an embodiment will be described with reference to the drawings. In the description of the drawings, the same elements are denoted by the same reference numerals, and redundant description is omitted. The dimensional ratios in the drawings do not necessarily match those described.

  As shown in FIG. 1, the battery pack 10 has a housing 11. A plurality of battery modules 21 are accommodated in the housing 11. The casing 11 has a rectangular box shape, a rectangular flat plate-like bottom plate 12, a rectangular flat plate-like side wall 13 standing from the periphery of the bottom plate 12, and a rectangular flat plate shape that closes an opening surrounded by the side wall 13. The top plate 14 is provided.

  As shown in FIG. 2, the battery module 21 includes a plurality of battery cells 23 (see FIG. 1), a pair of brackets (restraining portions) 25 and 25, an elastic member 47, bolts B and nuts N, and transmission. And a heat plate 41.

  The battery cell 23 is a secondary battery such as a lithium ion secondary battery or a nickel hydride storage battery. The battery cells 23 are juxtaposed in one direction D while being held by the battery holder 22. As shown in FIG. 3, the battery holder 22 includes a first covering portion 31, a second covering portion 32, a third covering portion 33, a fourth covering portion 34, a pair of leg portions 36 and 36, have.

  The first covering portion 31 is a portion that is formed in a rectangular flat plate shape and covers the bottom 24 a of the battery cell 23. The second covering portion 32 and the third covering portion 33 are portions erected from both longitudinal ends of the first covering portion 31. The second covering portion 32 and the third covering portion 33 are formed in a rectangular flat plate shape and cover the side surface 24 b of the battery cell 23. The fourth covering portion 34 is a portion that is formed in a rectangular flat plate shape and covers a part of one main surface (surface orthogonal to the thickness direction) 24 c of the battery cell 23. The fourth covering portion 34 includes a first end portion 32 a (an end portion opposite to the end portion on which the first covering portion 31 is provided) in the longitudinal direction of the second covering portion 32 and a longitudinal direction of the third covering portion 33. Is connected to the first end 33a (the end opposite to the end where the first covering portion 31 is provided). The fourth covering portion 34 is arranged such that the thickness direction thereof coincides with the juxtaposed direction of the battery cells 23 and the longitudinal direction thereof coincides with the opposing direction of the second covering portion 32 and the third covering portion 33. A region surrounded by the first covering portion 31, the second covering portion 32, and the third covering portion 33 is a housing portion S in which the battery cell 23 is housed.

  The first end portions 32a and 33a in the longitudinal direction of the second covering portion 32 and the third covering portion 33 are connected to the second covering portion 32 and the third covering portion 33, respectively. A rectangular flat plate-like projecting portion 35 extending in the longitudinal direction of the covering portion 33 is provided. In addition, square columnar leg portions 36 and 36 are provided at second end portions 32 c and 33 c in the longitudinal direction of the second covering portion 32 and the third covering portion 33, respectively.

  As shown in FIG. 1, the pair of brackets 25, 25 are provided at both ends of the battery cells 23 arranged in parallel in one direction D. The bracket 25 has a clamping part 25a, a fixing part 25b, and an insertion hole 25c formed in the fixing part 25b. The battery module 21 is fixed to the housing 11 by fixing the fixing portion 25 b of the bracket 25 to the side wall 13. Specifically, the bracket 25 is fixed to the housing 11 by a bolt (not shown) inserted through the insertion hole 25 c being screwed into the side wall 13.

  As shown in FIG. 2, the elastic member 47 is disposed at one end of the array 28. The array body 28 and the elastic member 47 are restrained in a state where they are pressed in the array direction (one direction D) of the battery cells 23 by bolts B and nuts N described in detail later. The elastic member 47 absorbs the expansion of the battery cell 23 within a certain range.

  The bolt B and the nut N connect the pair of brackets 25 and 25 to each other. Bolts B are inserted through the pair of brackets 25, 25. The bolt B is inserted from one bracket 25 toward the other bracket 25 and is screwed into the nut N at a position where the other bracket 25 is inserted. The pair of brackets 25, 25 are arranged so as to contact a plurality of battery cells 23 arranged in one direction D and a main surface 24 c that is a surface intersecting one direction D (array direction) of the battery cells 23. The plurality of heat transfer plates 41 and the array body 28 and the elastic member 47 are restrained in a state of being pressed in one direction D.

  As shown in FIGS. 3 and 4, the heat transfer plate 41 is a plate-like member disposed in contact with the main surface 24 c of the battery cell 23 accommodated in the battery holder 22. As shown in FIG. 5A, the heat transfer plate 41 is formed, for example, by bending a metal plate such as aluminum, and has a rectangular plate-like first main body portion 42 and a first main body. A rectangular flat plate-like second main body portion 43 bent at an acute angle (90 degrees or less) from one longitudinal end of the portion 42. The first main body portion 42 is provided in the accommodating portion S in a state adjacent to the battery cell 23 in the thickness direction of the battery cell 23. The second main body portion 43 covers one side surface 24 b of the third covering portion 33 (the surface on the opposite side of the housing portion S in the thickness direction surface of the third covering portion 33).

  The second main body 43 is bent from the first main body 42 by an angle α. In other words, the extending direction of the first main body portion 42 and the extending direction of the second main body portion 43 intersect at an angle α. The second main body 43 is bent from the first main body 42 in the direction in which the elastic member 47 is disposed. As shown in FIG. 4, the angle α at which the first main body portion 42 and the second main body portion 43 intersect is a heat transfer plate that contacts the battery cell 23 located at the center of the array 28 in one direction D. 41 (heat transfer plate 41D) is larger (for example, the angle α is 80 degrees to 89 degrees), and in one direction D, the heat transfer plate 41 (heat transfer plate 41A) is in contact with the battery cell 23 located at the end of the array 28. , 41G) is smaller (for example, the angle α is 60 degrees to 80 degrees).

  Specifically, as shown in FIG. 4, the battery cell 23A, the battery cell 23B, the battery cell 23C, and the battery cell 23D are arranged in this order from one end side of the array 28, and the angle α (FIG. 5A )) Increases in the order of the heat transfer plate 41A, the heat transfer plate 41B, the heat transfer plate 41C, and the heat transfer plate 41D, which are in contact with these main surfaces 24c, respectively. Similarly, the battery cell 23G, the battery cell 23F, the battery cell 23E, and the battery cell 23D are arranged in this order from the other end side of the array 28, and the angle α is a heat transfer plate that is in contact with each of the main surfaces 24c. The size increases in the order of 41G, heat transfer plate 41F, heat transfer plate 41E, and heat transfer plate 41D.

  As shown in FIG. 5B, a curved portion 44 that smoothly bends from one end side of the first main body portion 42 is formed on the first main body portion 42 side of the second main body portion 43. For example, when the thickness of the heat transfer plate 41 is 3 mm, the curved portion 44 can have a curved radius of the outer portion 44a of 6 mm and a curved radius of the inner portion 44b of 3 mm. A part of the curved portion 44 is in contact with a heat conducting member 51 described later.

  The battery module 21 having the above-described configuration is attached to the side wall 13 of the housing 11 to form the battery pack 10 as shown in FIG. As shown in FIGS. 6 and 7, when the battery module 21 is attached to the side wall 13 of the housing 11, it is attached by a pair of brackets 25, 25. Further, a TIM (Thermal Interface Material) as the heat conducting member 51 is disposed between the array 28 and the side wall 13. That is, the 2nd main-body part 43 of the heat-transfer plate 41 is contacting the side wall 13 of the housing | casing 11 via TIM.

  The heat conducting member 51 is a member made of a sheet-like material whose both surfaces are adhesive. The heat conducting member 51 has insulating properties. As the heat conductive member having such an insulating property, a heat conductive sheet not including a metal filler can be used. In addition, the heat conductive member 51 includes a silicone heat conductive sheet and an acrylic heat conductive sheet. When a silicone-based heat conductive sheet is used, the range of operating temperature can be widened because of excellent cold resistance and heat resistance. In addition, a silicone-based heat conductive sheet that does not use a metal filler is suitable for an insulating material because the change in electrical characteristics due to temperature and frequency is small. On the other hand, since the acryl-based sheet does not generate siloxane gas, the contact failure of the mechanical contact and the abrasion do not occur in the sealed space. Acrylic sheets are generally less expensive than silicone.

  In the battery module 21 of the present embodiment, the heat transfer plate 41 is such that the angle α, which is the intersection angle between the first main body portion 42 and the second main body portion 43 in the heat transfer plate 41, is located at the center of the array 28 in one direction D. Since it is as large as 41, the heat transfer plate 41 located in the center of the array 28 in one direction D has a larger contact area with the heat conducting member 51. Therefore, the battery module 21 is attached to the side wall 13 in a state in which the reaction force received from the heat conducting member 51 is greater in the heat transfer plate 41 located in the center of the array body 28 in the one direction D. In other words, the battery module 21 having this configuration is attached to the side wall 13 in a state where the reaction force received from the heat conducting member 51 is smaller in the heat transfer plate 41 located at the end of the array 28 in one direction D.

  Next, the effect of the battery module 21 of the said embodiment is demonstrated. According to the battery module 21 of the above embodiment, since the first main body portion 42 and the second main body portion 43 intersect at an acute angle, the heat transfer plate 41 includes the first main body portion 42, the second main body portion 43, and the like. In contact with the heat conducting member 51 at the intersection. As a result, the contact area between the heat transfer plate 41 and the heat conducting member 51 is smaller than the entire surface of the second main body 43 being in contact with the heat conducting member 51. The reaction force received from 51 is reduced. For this reason, the shift | offset | difference of the battery cell 23 to the direction which cross | intersects the side wall 13 of the housing | casing 11 is suppressed, and possibility that the heat-transfer plate 41 and the heat conductive member 51 will not contact can be made small. As a result, it is possible to suppress a decrease in heat dissipation efficiency due to a change with time.

  In the battery module 21 of the above embodiment, the first main body portion 42 side of the second main body portion 43 is formed with a curved portion 44 that bends smoothly from one end side of the first main body portion 42. Thereby, the said curve part 44 and the heat conductive member 51 come to contact. As a result, even if the heat transfer plate 41 moves in one direction D due to the expansion of the battery cells 23, damage to the heat conducting member 51 by the heat transfer plate 41 can be suppressed.

  In the battery module 21 having such a configuration, for example, as shown in FIG. 8, the heat transfer plate 41 moves along the one direction D (to the left in FIG. 8) by the movement amount M <b> 1 due to the expansion of the battery cells 23. The case will be described. The battery module 21 is attached to the side wall 13 of the housing 11 so as to be pressed against the heat conducting member 51. Thereby, the heat conductive member 51 is in a state of being deformed in accordance with the shape of the second main body portion 43 of the heat transfer plate 41. When the heat transfer plate 41 moves in one direction D in such a state, the second main body portion 43 of the heat transfer plate 41 moves toward the heat conducting member 51 with a small degree of deformation. That is, when the heat transfer plate 41 moves, the heat transfer plate 41 is pressed against the heat conduction member 51 with a small degree of deformation, and the contact between the heat conduction member 51 and the heat transfer plate 41 is maintained.

  In the battery module 21 that restrains the plurality of battery cells 23 in a state of being pressed in one direction D by the pair of brackets 25 and 25 as in the above embodiment, the battery cells 23 positioned at both ends of the array 28 The restraint force by restraint parts, such as the volt | bolt B and the nut N, is strong, and the heat-transfer plate 41 receives the reaction force from the heat conductive member 51 strongly. In this regard, in the battery module 21 of the above-described embodiment, the crossing angle α between the first main body portion 42 and the second main body portion 43 is such that the heat transfer plate 41 that receives the reaction force from the heat conductive member 51 more strongly. 51 is formed such that the bending angle α of the portion in contact with 51 is reduced, and the reaction force received from the heat conducting member 51 is reduced. Therefore, the influence of the reaction force received from the heat conducting member 51 can be reduced. As a result, it is possible to further suppress a decrease in heat dissipation efficiency associated with a change with time.

  Although one embodiment has been described above, the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the invention.

  In the above embodiment, as shown in FIG. 4, the angle α at which the first main body portion 42 and the second main body portion 43 intersect with each other contacts the battery cell 23 positioned at the center of the array 28 in the one direction D. Although the heat transfer plate 41 has been described as an example of gradually increasing size, the heat transfer plate 41 that contacts the battery cell 23 located in the center of the array 28 in one direction D may be gradually increased. All may be the same.

  In the said embodiment or modification, although the 2nd main-body part 43 in the heat-transfer plate 41 gave and demonstrated the example bent in the direction in which the elastic member 47 was arrange | positioned from the 1st main-body part 42, all the heat transfer was demonstrated. A part or all of the second main body 43 in the plate 41 may be bent from the first main body 42 to the opposite side to the direction in which the elastic member 47 is arranged.

  In the said embodiment or the modification, although the battery module 21 of the said embodiment gave and demonstrated the example provided with the heat-transfer plate 41 in which the curve part 44 was formed in the 1st main body part 42 side of the 2nd main body part 43, it demonstrated. The heat transfer plate 41 in which the curved portion 44 is not formed may be provided. Further, the second main body portion 43 is not flat (straight in a side view) as in the above-described embodiment or modification, for example, the tip portion on the opposite side to the side intersecting the first main body portion 42 is upward ( It may be formed in a shape that bends in a direction away from the heat conducting member 51, or may be formed so that the thickness of the tip portion is reduced. Thereby, when the battery cell 23 expand | swells, it can suppress that the front-end | tip part of the 2nd main-body part 43 is caught by the heat conductive member 51, and can suppress damage to the heat conductive member 51. FIG.

  In the above-described embodiment or modification, the battery module 21 restrained in a state where the array body 28 is pressed in one direction D by the pair of brackets 25 and 25 having a function of attaching to the housing 11 has been described as an example. However, the battery module of the structure restrained in the state which pressurized the array 28 to the one direction D with a pair of end plate which does not have the attachment function to the housing | casing 11 may be sufficient. The battery module having this configuration is attached to the housing 11 by, for example, a bracket that is a separate member from the pair of end plates.

  In the said embodiment or modification, although the elastic member 47 gave and demonstrated the example arrange | positioned only at one edge part of the array 28, this invention is not limited to this. For example, the elastic member 47 may be disposed at both ends of the array 28, or may be disposed between the battery cells 23. In addition, the elastic member 47 may be distributed between all or some of the battery cells 23.

  In the above-described embodiment or modification, the elastic member 47 formed of an elastic material such as urethane rubber has been described as an example. However, the present invention is not limited thereto, and for example, an elastic member such as a spring. It may be.

  In the said embodiment or modification, although the battery module 21 in which the battery cell 23 of the state hold | maintained at the battery holder 22 was arranged in parallel was mentioned as an example, it was not hold | maintained at the battery holder 22, but only the battery cell 23 was demonstrated. You may use the battery module 21 which consists of.

  In the above-described embodiment or modification, the side wall 13 of the housing 11 in the battery pack 10 is described as an example of the member to be fixed, but a counterweight mounted on an industrial vehicle may be used.

  Various embodiments and modifications described above may be combined in various ways without departing from the spirit of the present invention.

  DESCRIPTION OF SYMBOLS 10 ... Battery pack, 11 ... Housing | casing, 13 ... Side wall, 21 ... Battery module, 22 ... Battery holder, 23 (23A-23G) ... Battery cell, 24c ... Main surface of a battery cell, 25 ... Bracket (restraint part), 25a ... clamping part, 25b ... fixing part, 25c ... insertion hole, 28 ... array, 41 (41A-41G) ... heat transfer plate, 42 ... first body part, 43 ... second body part, 44 ... curve part, 47: elastic member, 51: heat conducting member, B: bolt (restraint portion), N: nut (restraint portion), D: one direction (arrangement direction).

Claims (4)

A battery module attached to the housing via a heat conducting member,
A plurality of battery cells arranged in one direction, and a plurality of heat transfer plates arranged in contact with a main surface that is a surface intersecting the one direction of the battery cells and arranged in the one direction. An array having
A restraining portion for restraining the arrayed body in a state of being pressed in the one direction;
With
The heat transfer plate is
A first main body that contacts the main surface;
A second body part that is bent in a direction intersecting the main surface from one end side of the first body part and is in contact with the heat conducting member;
The battery module, wherein the first main body and the second main body intersect at an acute angle.   The battery module according to claim 1, wherein the first main body portion side of the second main body portion is formed with a curved portion that bends smoothly from one end side of the first main body portion.   The battery according to claim 1, wherein an intersection angle between the first main body portion and the second main body portion is larger as the heat transfer plate is in contact with the battery cell located at the center of the array in the one direction. module. An elastic member disposed at one end of the array;
The restraining portion restrains the array body and the elastic member in a state where the array member and the elastic member are pressurized in the one direction,
The battery module according to claim 1, wherein the second main body is bent from the first main body in a direction in which the elastic member is disposed.

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