JP2017054693A - Battery pack - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a battery pack which secures ease of assembly of a battery module to a housing and good heat radiation performance of the battery module.SOLUTION: A battery pack 1 includes: a housing 2; a frame body 11 disposed in the housing 2; and a battery module 3 having an array body 22 of battery cells 21 and a plate-like bracket 24 which is provided so as to sandwich the array body 22 in an arrangement direction of the battery cells 21. The bracket 24 is fixed to the frame body 11 in a state where a side surface 3a of the battery module 3, which intersects with the arrangement direction of the array body 22, contacts with an inner wall of the housing 2.SELECTED DRAWING: Figure 5

Description

  The present invention relates to a battery pack.

  As a conventional battery pack, there is a battery pack described in Patent Document 1, for example. This battery pack is configured by housing a plurality of battery modules in a housing. Each battery module is fixed to the inner wall of the housing by a fastening member such as a bolt via a bracket attached to the end plate. A heat transfer plate is disposed between the battery cells of each battery module, and heat generated in the battery cells is radiated to the side wall side of the housing through the heat transfer plate.

Japanese Patent Laying-Open No. 2015-50057

  In the battery pack as described above, a structure for facilitating the assembly of the battery module to the housing has been studied. As such a structure, a structure in which the battery module is not directly assembled to the housing but a frame body assembled with the battery module is accommodated in the housing is conceivable. Even in a structure using a frame, it is required to ensure heat dissipation of the battery module on the premise of heat transfer to the housing.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a battery pack that can satisfactorily ensure the ease of assembly of the battery module to the housing and the heat dissipation of the battery module.

  In order to solve the above-described problem, a battery pack according to one aspect of the present invention has a housing, a frame body disposed in the housing, an array of battery cells, and the array body sandwiched in the array direction of the battery cells. A battery module having a plate-like bracket provided on the battery module, and the bracket is fixed to the frame body with the side surface intersecting the arrangement direction of the battery array in the battery module being in contact with the inner wall of the housing .

  In this battery pack, the heat generated in the battery cells can be radiated to the housing side by bringing the side surface intersecting the arrangement direction of the array body in the battery module into contact with the inner wall of the housing. Further, in this battery pack, by assembling a frame body in which the battery module is pre-assembled in the housing, it is possible to secure the ease of assembling the battery module to the housing as compared with the case where the battery module is directly assembled to the housing. . At this time, by using a flat bracket in the battery module, the battery module can be easily positioned with respect to the frame, and the side surface of the battery module and the inner wall of the housing can be brought into contact with no gap. Therefore, good heat dissipation of the battery module can be ensured.

  Further, in the array, a heat transfer plate is disposed between the battery cells, and the heat transfer plate has an extending surface extending to the side surface of the battery module, and the extending surface is formed on the inner wall of the housing as the side surface of the battery module. You may contact | abut. In this case, the extended surface of the heat transfer plate abuts against the inner wall of the housing, so that the heat dissipation of the battery module can be further improved.

  Moreover, the side surface of the battery module may be positioned flush with the end surface of the bracket or outside the end surface of the bracket when viewed from the arrangement direction of the battery cells. Thereby, the side surface of a battery module and the inner wall of a housing | casing can be contact | abutted more reliably without gap.

  In addition, the bracket is provided with a notch according to the cross-sectional shape of the beam portion constituting the frame, and the bracket is fastened to the frame by a fastening member in a state where the beam is engaged with the notch. Also good. In this case, it becomes easier to position the battery module with respect to the frame.

  Moreover, a fastening member is a volt | bolt and the volt | bolt may be distribute | arranged in the direction which cross | intersects the sequence direction of an array body. If it carries out like this, it can prevent that the fastening force by a volt | bolt influences the binding force of each battery cell in a battery module.

  According to the battery pack of one aspect of the present invention, it is possible to satisfactorily ensure the ease of assembling the battery module to the housing and the heat dissipation of the battery module.

It is a perspective view which shows one Embodiment of the battery pack which concerns on this invention. It is a perspective view which shows an example of the frame used for accommodation of a battery module. It is a perspective view which shows an example of a battery module. It is a perspective view which shows an example of the battery cell which comprises a battery module. It is the schematic which shows the accommodation state of the battery module with respect to a housing | casing. It is the schematic which shows the modification of the accommodation state of the battery module with respect to a housing | casing. It is the schematic which shows another modification of the accommodation state of the battery module with respect to a housing | casing.

  Hereinafter, preferred embodiments of a battery pack according to one aspect of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a perspective view showing an embodiment of a battery pack according to the present invention. The battery pack 1 shown in the figure is mounted as a battery in various vehicles such as automobiles and forklifts. As shown in FIG. 1, the battery pack 1 is configured by housing a plurality of battery modules 3 in a housing 2.

  The housing | casing 2 is formed, for example with metal materials, such as iron (SS400), and has comprised the substantially rectangular parallelepiped box as a whole. Inside the housing 2 is a housing space S in which the battery module 3 and a control board (not shown) are housed. The housing 2 has a bottomed main body 4 and a lid 5 that closes an opening on one surface side of the main body 4.

  The main body 4 includes, for example, a base plate 6 and a plurality of side plates 7 that are erected on four sides of the base plate 6. The base plate 6 and the side plate 7 are each formed of a rectangular flat plate member, and the main body 4 is formed by welding the edge of the base plate 6 and the edge of the side plate 7 together. The thickness of the base plate 6 may be larger than the thickness of the side plate 7. The lid 5 is made of a rectangular flat plate member having the same shape as the base plate 6, for example. The lid 5 is fixed to the edge of the side plate 7 by a fastening member such as a bolt or by welding, and closes the opening of the main body 4 in an airtight and watertight manner.

  For housing the battery module 3 in the housing space S of the housing 2, a frame 11 is used as shown in FIG. 2. The frame body 11 is configured by connecting, for example, metal beam portions 12 by welding or the like, and has a substantially rectangular parallelepiped shape so as to fit into the accommodation space S with almost no gap. The beam portion 12 has, for example, a bar shape having a square cross section, and includes an outer portion that forms a substantially rectangular parallelepiped outer shape of the frame 11 and an inner portion that connects the midpoints of the outer portion. Thus, a plurality of substantially rectangular parallelepiped assembling regions K for assembling the battery module 3 are formed in the frame 11. Note that the width of the beam portion 12 (beam portion 12a) constituting the central portion in the width direction of the frame 11 is such that the assembly portions K, K adjacent to the left and right by the beam portion 12 are configured in common. It is about twice the width of the other beam portion 12.

  In FIG. 1, the single battery module 3 is illustrated in the housing 2, but in this embodiment, a 4 × 2 assembly region K is provided in the frame body 11, and a maximum of 8 bodies are provided. The battery module 3 can be assembled. Further, insertion holes (not shown) through which the bolts 28 used for assembling the battery module 3 are inserted are formed in the beam portion 12 constituting the bottom of the assembling region for each assembling region K (FIG. 5). reference).

  As shown in FIG. 3, the battery module 3 assembled to the frame body 11 includes an array body 22 in which a plurality of battery cells 21 are arrayed, and a restraining load is applied to the array body 22 in the array direction of the battery cells 21. And a restraining member 23 to be used. In the array 22, a plurality of battery cells 21 are arrayed via a heat transfer plate 48 (see FIG. 4). At one end of the array 22, for example, an elastic body (not shown) formed in a rectangular plate shape by a rubber sponge made of urethane is disposed.

  Examples of the elastic material include ethylene propylene diene rubber (EPDM), chloroprene rubber, and silicon rubber. Further, the elastic body is not limited to rubber, and may be a spring material or the like. The elastic body is a member used for the purpose of preventing the battery cell 21 from being damaged by a restraining load, and may be disposed at both ends in the arrangement direction of the battery cell 21 or between the battery cells 21 and 21. Also good.

  The restraining member 23 includes a pair of brackets 24 and 24 and a fastening member that fastens the brackets 24 and 24 together. The brackets 24 are substantially rectangular flat plate members that also function as end plates of the array body 22, and are respectively disposed at both ends of the battery cells 21 in the array direction so as to sandwich the array body 22 and the elastic bodies. The thickness of the bracket 24 is, for example, approximately the same as the length of one side of the cross section of the beam portion 12 in the frame body 11.

  Cutout portions 24 a having shapes corresponding to the cross-sectional shape of the beam portion 12 in the frame 11 are respectively provided at the corners on the bottom side of the bracket 24. In the present embodiment, the cross-sectional shape of the beam portion 12 is a square shape, and the shape of the cutout portion 24a is also a square shape. The length of one side of the notch portion 24a is approximately half the width of the beam portion 12a (equal length to one side of the other beam portions 12) because the beam portion 12a is shared between the adjacent assembling regions K and K. ). A bolt hole (not shown) into which a bolt 28 described later is screwed is provided on the end surface 24b facing the bottom side of the bracket 24 among the end surfaces constituting the notch 24a (see FIG. 5).

  The fastening member includes, for example, a long bolt 25 and a nut (not shown) that is screwed into the bolt 25. The bolts 25 are inserted into the battery module 3 at the positions of the upper and lower edges of the bracket 24, for example. By screwing a nut from the outside of the bracket 24 to the tip of each bolt 25, the battery cell 21, the heat transfer plate 48, and the elastic body are sandwiched and unitized, and a restraining load is applied.

  The battery cell 21 is a storage battery such as a nonaqueous electrolyte secondary battery such as a lithium ion secondary battery. As shown in FIG. 4, for example, a hollow case 32 having a substantially rectangular parallelepiped shape and an electrode assembly 33 accommodated in the case 32 are provided. The case 32 is formed of a metal such as aluminum, for example, and an organic solvent-based or non-aqueous electrolyte is injected into the case 32, for example. On the top surface of the case 32, a pair of electrode terminals 34, 34 are arranged apart from each other. One electrode terminal 34 is a positive electrode terminal and is electrically connected to the positive electrode of the electrode assembly 33. The other electrode terminal 34 is a negative electrode terminal and is electrically connected to the negative electrode of the electrode assembly 33.

  The electrode assembly 33 includes a positive electrode, a negative electrode, and a separator disposed between the positive electrode and the negative electrode. The positive electrode, the negative electrode, and the separator all have a sheet shape, and the separator is disposed between the positive electrode and the negative electrode that are alternately stacked. The separator may be bag-shaped. In this case, for example, bag-shaped separators containing positive electrodes and negative electrodes are alternately stacked.

  Each battery cell 21 is held by a cell holder 41. As shown in FIG. 4, the cell holder 41 includes a frame body 42, a partition portion 43, a terminal accommodating portion 44, and a bolt guide portion 45. The frame body 42 includes a bottom plate 46 and a pair of side plates 47 and 47 erected on the edge of the bottom plate 46 in the width direction. The partition portion 43 is a plate-like member provided substantially in parallel with the bottom plate 46. The partition 43 connects the side plates 47 and 47 at a position corresponding to the height of the case 32 of the battery cell 21. With such a configuration, when the battery cell 21 is fitted into the cell holder 41, the bottom surface 32b of the case 32 and the side surface 32c in the width direction are exposed in a state where the side surface 32a of the array body 22 in the case 32 is exposed from the frame body 11. Is held by the frame 42 of the cell holder 41.

  The terminal accommodating portion 44 is a portion that accommodates the electrode terminals 34, 34 of the battery cell 21. The terminal accommodating portion 44 is provided on the partition portion 43 and surrounds the electrode terminals 34 and 34 when the battery cell 21 is fitted in the frame body 42. The bolt guide portion 45 is a portion through which the bolt 25 of the restraining member 23 is inserted. The bolt guide portions 45 are provided on the partition portion 43 and the bottom plate 46, respectively. The bolt guide portion 45 on the partition portion 43 side is provided on the partition portion 43 inside the terminal housing portion 44 and adjacent to the terminal housing portion 44. The bolt guide portion 45 on the bottom plate 46 side is provided on the bottom surface side of the bottom plate 46 at the end in the width direction of the bottom plate 46.

  A heat transfer plate 48 is attached to the cell holder 41. The heat transfer plate 48 is formed of a member having heat transfer properties such as aluminum, for example, and contacts the side surface 32a in the arrangement direction of the array 22 in the case 32 of the battery cell 21, and the width of the cell contact surface 48a. And an extending surface 48b extending substantially perpendicularly from one end in the direction. The cell contact surface 48a and the side surface 32a of the case 32 are fixed to each other by, for example, a heat-resistant double-sided tape.

  The extending surface 48 b is located outside the side plate 47 of the frame body 42 in the cell holder 41. As shown in FIG. 3, the side plate 47 of the frame body 42 and the extended surface 48 b of the heat transfer plate 48 in the cell holder 41 constitute a side surface 3 a of the battery module 3 in the width direction (direction intersecting the array direction of the array body 22). doing. In the present embodiment, of the side surface 3a of the battery module 3, the side plate 47 of the frame body 42 in the cell holder 41 is flush with the end surface 24c in the width direction of the bracket 24, and the extended surface 48b of the heat transfer plate 48 is The protruding surface 48b protrudes laterally from the end surface 24c in the width direction of the bracket 24 by the thickness of the extending surface 48b.

  Next, the accommodation state of the battery module 3 with respect to the housing 2 will be described in more detail.

  As shown in FIG. 5, the frame 11 is fitted into the housing space S of the housing 2 with almost no gap. Further, the battery module 3 is assembled to the assembly region K of the frame body 11. In assembling the battery module 3 and the frame body 11, the bracket 24 in the battery module 3 is stretched over a pair of beam portions 12 and 12 a constituting the bottom surface side of the assembly region K. The notches 24a and 24a of the bracket 24 are engaged with the pair of beam portions 12 and 12a, and the battery module 3 is held in a state of being positioned in the width direction with respect to the beam portions 12 and 12a. And the battery module 3 is screwed into the bolt hole of the bracket 24 by screwing the front end side of the bolt 28 inserted into the insertion hole of the beam part 12 from the bottom side of the beam parts 12 and 12a to the beam parts 12 and 12a. On the other hand, it is firmly fixed.

  In a state where the notches 24 a and 24 a of the bracket 24 are engaged with the pair of beam portions 12 and 12 a, the side surface 3 a in the width direction of the battery module 3 faces the side plate 7 of the housing 2. The end surface 24c in the width direction of the bracket 24 and the side plate 47 of the frame body 42 in the cell holder 41 are separated from the inner wall surface 7a of the side plate 7 of the housing 2 by the thickness of the extending surface 48b of the heat transfer plate 48. Yes. On the other hand, the extending surface 48b of the heat transfer plate 48 is flush with the side surface in the width direction of the frame 11 (the outer surface of the beam portion 12 constituting the side surface), and a gap is formed between the inner wall surface 7a of the side plate 7. There is no contact.

  As described above, in the battery pack 1, the heat generated in the battery cell 21 is transferred by bringing the extended surface 48 b of the heat transfer plate 48 in the battery module 3 into contact with the inner wall surface 7 a of the side plate 7 in the housing 2. Heat can be radiated to the housing 2 via the heat plate 48. Moreover, in this battery pack 1, the battery module 3 with respect to the housing | casing 2 is compared with the case where the battery module 3 is directly assembled | attached to the housing | casing 2 by accommodating the frame 11 in which the battery module 3 was previously assembled | attached in the housing | casing 2. 3 is easy to assemble. At this time, by using the flat bracket 24 in the battery module 3, the battery module 3 can be easily positioned with respect to the frame body 11, and the extended surface of the heat transfer plate 48 and the inner wall surface 7 a of the side plate 7 in the housing 2 are connected. It is possible to make contact with no gap. Therefore, the heat dissipation of the battery module 3 can be ensured satisfactorily.

  Further, in the battery module 3, when viewed from the arrangement direction of the battery cells 21, the extending surface 48 b that is a part of the side surface 3 a of the battery module 3 has an end surface 24 c in the width direction of the bracket 24 corresponding to the thickness of the extending surface 48 b. It is located outside. Thereby, the extended surface 48b of the heat-transfer plate 48 and the inner wall surface 7a of the side plate 7 in the housing 2 can be brought into contact with each other more reliably without a gap.

  In the battery module 3, a notch 24 a corresponding to the cross-sectional shape of the beam portions 12 and 12 a constituting the frame body 11 is provided at the corner of the bracket 24. The bracket 24 is fastened to the frame body 11 with bolts 28 in a state where the beam portions 12 and 12a are engaged with the notch portion 24a. In this way, the battery module 3 can be positioned more easily with respect to the frame 11 by engaging the notch 24a with the beams 12 and 12a.

  Further, as shown in FIG. 5, the bolts 28 for fastening the bracket 24 to the beam portion 12 are arranged from the bottom side of the beam portions 12 and 12a toward the bracket 24 side. The battery module 3 has a direction that intersects the arrangement direction of the array bodies 22. With such a configuration, it is possible to prevent the fastening force by the bolt 28 from affecting the binding force of each battery cell in the battery module 3.

  The present invention is not limited to the above embodiment. For example, in the above embodiment, the notch 24a is provided at the corner of the bracket 24, but the notch 24a is not necessarily provided. Moreover, in the said embodiment, although the end surface 24c of the width direction of the bracket 24 and the inner wall surface 7a of the side plate 7 in the housing | casing 2 are spaced apart (refer FIG. 5), as shown in FIG. The end surface 24c in the direction and the extending surface 48b of the heat transfer plate 48 may be flush with each other, and both the end surface 24c in the width direction of the bracket 24 and the extending surface 48b may be in contact with the inner wall surface 7a of the side plate 7.

  In addition, as shown in FIG. 7, when a heat conductive sheet 50 such as TIM (Thermal Interface Material) is arranged on the inner wall surface 7 a of the side plate 7, the heat transfer plate 48 has a thickness corresponding to the thickness of the heat conductive sheet 50. The extending surface 48b may be positioned inside. In this case, the extending surface 48 b of the heat transfer plate 48 may be located inside the end surface 24 c in the width direction of the bracket 24.

  Further, in the above embodiment, the extended surface 48b of the heat transfer plate 48 is in contact with the inner wall surface 7a of the side plate 7 in the housing 2 as the side surface 3a in the width direction of the battery module 3, but the heat transfer plate 48 is not used. The side plate 47 of the frame body 42 in the cell holder 41 may abut on the inner wall surface 7a of the side plate 7 in the housing 2 as the side surface 3a in the width direction of the battery module 3. Further, without using the cell holder 41, the side surface 32 c in the width direction of the case 32 in the battery cell 21 may abut on the inner wall surface 7 a of the side plate 7 in the housing 2 as the side surface 3 a in the width direction in the battery module 3.

  DESCRIPTION OF SYMBOLS 1 ... Battery pack, 2 ... Housing | casing, 3 ... Battery module, 3a ... Side surface, 11 ... Frame, 12, 12a ... Beam part, 21 ... Battery cell, 22 ... Array, 24 ... Bracket, 24a ... Notch part, 24c ... end face, 28 ... bolt (fastening member), 48 ... heat transfer plate, 48b ... extension surface.

Claims (5)

A housing,
A frame disposed in the housing;
A battery module having an array of battery cells and a flat bracket provided so as to sandwich the array in the array direction of the battery cells,
The battery pack in which the bracket is fixed to the frame body in a state in which side surfaces intersecting the arrangement direction of the array body in the battery module are in contact with an inner wall of the housing. In the array, a heat transfer plate is disposed between the battery cells,
The heat transfer plate has an extending surface extending to the side surface of the battery module,
The battery pack according to claim 1, wherein the extending surface is in contact with an inner wall of the housing as the side surface of the battery module.   The battery pack according to claim 1, wherein the side surface of the battery module is positioned flush with an end surface of the bracket or on an outer side than the end surface of the bracket when viewed from the arrangement direction of the battery cells. The bracket is provided with a notch according to the cross-sectional shape of the beam portion constituting the frame,
The battery pack according to any one of claims 1 to 3, wherein the bracket is fastened to the frame body by a fastening member in a state where the beam part is engaged with the notch part. The fastening member is a bolt,
The battery pack according to claim 4, wherein the bolts are arranged in a direction intersecting with the arrangement direction of the array.

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