JP2019096510A - Battery module - Google Patents

Abstract

To provide a technology that can suppress misalignment between cells in a battery module.SOLUTION: A battery module 1 includes a cell stack 2 configured by stacking a plurality of cells 21 in the front-rear direction, a pair of end plates 3 disposed on the front and back surfaces of the cell stack 2, a pair of connecting frames 4 connecting the pair of end plates 3, a base plate 5 disposed on the lower surface of the cell stack 2, and a pair of fixing members 7 for urging the cell stack 2 and the base plate 5 in a direction in which the cell stack 2 and the base plate 5 approach each other. The base plate 5 has a plate main body 51 extending along the lower surface of the cell stack 2 and a pair of plate wall portions 53. The connecting frame 4 is disposed on an extension line of the plate wall portion 53 in the vertical direction.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a battery module mounted on an electric vehicle or the like.

  Conventionally, a battery module is mounted on an electric vehicle or the like. For example, Patent Document 1 discloses a battery module including a cell stack, a pair of end plates disposed at both ends of the cell stack in the stacking direction, and a pair of ladder frames connecting the pair of end plates. Is disclosed.

JP 2012-256466 A

  In this type of battery module, positional deviation between cells constituting the cell stack may be a problem. For example, when an external force in the vertical direction acts, if the cells are misaligned, stress may be generated in the bus bars connecting the terminals of the cells to cause connection failure.

  The present invention provides a technique capable of suppressing positional deviation between cells in a battery module.

The present invention relates to a battery module,
A plurality of cells are stacked in a first direction, and a first surface which is a surface on one end side in the first direction, a second surface which is a surface on the other end side in the first direction, and the first direction The third surface which is the surface on the one end side in the second direction which is the orthogonal direction, the fourth surface which is the surface on the other end side in the second direction, the third direction which is orthogonal to the first direction and the second direction A cell stack having a fifth surface which is a surface on one end side and a sixth surface which is a surface on the other end side in the third direction;
A pair of end plates disposed on the first surface and the second surface of the cell stack;
A pair of connecting frames disposed on the third surface and the fourth surface of the cell stack and connecting the pair of end plates;
A base plate disposed on the sixth surface of the cell stack;
And a pair of fixing members for urging the cell stack and the base plate in directions approaching each other,
The base plate is
A plate body extending along the sixth surface of the cell stack;
At both end portions of the plate main body in the second direction, it projects from the mounting surface on which the cell stack is mounted along the third surface and the fourth surface of the cell stack, and along the first direction. And a pair of extending plate walls;
The connection frame is disposed on an extension of the plate wall in the third direction.

  According to the present invention, the rigidity of the base plate is improved because the base plate has the plate wall portions erected at both ends of the plate body. Thereby, the bending of the base plate can be suppressed, and positional deviation between cells constituting the cell stack can be suppressed. Further, since the connecting frame connecting the pair of end plates is disposed on the extension of the plate wall in the third direction, the base plate is bent even when the battery module receives an external force in the third direction. The directional force is received by the connecting frame. Therefore, positional deviation between cells constituting the cell stack can be further suppressed.

It is a perspective view of a battery module concerning one embodiment of the present invention. It is a disassembled perspective view of the battery module of FIG. It is a principal part top view of the battery module of FIG. It is AA sectional drawing of FIG. It is a BB sectional view of FIG. It is a fragmentary perspective view which shows the connection frame and fixing member of the battery module of FIG.

  Hereinafter, an embodiment of a battery module of the present invention will be described based on the attached drawings. The drawings should be viewed in the direction of the reference numerals.

Battery module
As shown in FIG. 1, the battery module 1 according to the embodiment of the present invention is configured by stacking a plurality of cells 21 in the front-rear direction, and has a cell stack having a front surface, a rear surface, a left surface, a right surface, an upper surface, and a lower surface. 2, a pair of end plates 3 disposed on the front and rear faces of the cell stack 2, a pair of connection frames 4 disposed on the left and right faces of the cell stack 2 and connecting the pair of end plates 3, and a cell A base plate 5 disposed on the lower surface of the laminate 2 and a pair of fixing members 7 urging the cell laminate 2 and the base plate 5 in directions approaching each other are provided.

  In the present specification and the like, the stacking direction of the cells 21 is defined as the front-rear direction, and the direction orthogonal to the stacking direction of the cells 21 is defined as the left-right direction and the top-bottom direction. It is irrelevant to the front-back direction etc. of the product in which the battery module 1 is mounted. That is, when the battery module 1 is mounted on a vehicle, the stacking direction of the cells 21 may coincide with the longitudinal direction of the vehicle, or may be the vertical direction, the lateral direction of the vehicle, or inclined from these directions It may be a direction. The drawings show the front of the battery module 1 as Fr, the rear as Rr, the left as L, the right as R, the upper as U, and the lower as D.

(Cell stack)
As shown in FIGS. 1 to 3, the cell stack 2 is configured by alternately stacking a plurality of cells 21 and a plurality of first insulating members 22 in the front-rear direction. A pair of end plates 3 is disposed on the front and back surfaces of the cell stack 2 in an insulating state via the second insulating member 23, and the bottom surface of the cell stack 2 is insulated via the third insulating member 24. In the state, the base plate 5 is disposed, and the pair of connection frames 4 is disposed on the left surface and the right surface of the cell stack 2 in an insulating state with a slight gap. A pair of fourth insulating members 6 is disposed at the left end and the right end on the top surface of the cell stack 2.

  A plurality of bus bars (not shown) electrically connected to the terminals 21 a of the cells 21 are disposed on the top surface of the cell stack 2. The bus bars include bus bars (not shown) for connecting the terminals 21 a of the cells 21 and bus bars for connecting the terminals 21 a of the cells 21 to the external connection terminal block 25. When the plurality of cells 21 constituting the cell stack 2 are displaced relative to each other, stress may be generated between the terminal 21a and the bus bar, and connection failure may occur. Therefore, it is desirable to suppress positional deviation between the cells 21 as much as possible.

(end plate)
As shown in FIGS. 1 to 3 and 5, the pair of end plates 3 abuts on the front surface and the rear surface of the cell stack 2 via the second insulating member 23, respectively, in the cell stack direction of the cell stack 2. Receive a load (hereinafter, also referred to as cell thickness restraint reaction force as appropriate). The load in the cell stacking direction of the cell stack 2 is mainly caused by expansion of the cell 21 due to temperature change and aging deterioration, and in the front and back faces of the cell 21, the horizontal central portion and the vertical central portion are Because of the ease of expansion, a large load is input to the lateral center portion and the vertical center portion of the end plate 3.

  The end plate 3 includes a central end plate portion 31 formed in a central region in the left and right direction, and a left end plate portion 32L and a right end plate portion 32R formed so as to sandwich the central end plate portion 31 in the left and right direction. Have. The central end plate portion 31 receiving a large load from the cell stack 2 in the cell stacking direction has a width in the front-rear direction larger than the width in the front-rear direction of the left end plate portion 32L and the right end plate portion 32R.

  The end plate 3 of the present embodiment is formed using an aluminum extruded material (aluminum alloy material), and is in close contact with the front surface and the rear surface of the cell stack 2 via the second insulating member 23 to make the cell stack 2 It also functions as a heat dissipating member that transfers heat from the heat source to dissipate heat.

  A base plate fastening portion 31a fastened to the base plate 5 via a rivet R is provided on the lower surface portion of the central end plate portion 31, and the connection frame 4 is provided on the outer surface portion of the left end plate portion 32L and the right end plate portion 32R. And a plurality of connecting frame fastening portions 32a fastened via bolts B1. Further, an external connection terminal block fixing portion 31b to which the external connection terminal block 25 is fixed via the bolt B2 is provided on the upper surface portion of the central end plate portion 31 and the right end plate portion 32R.

(Connected frame)
As shown in FIGS. 1 to 4 and 6, the pair of connection frames 4 includes a connection frame main body 41 along the left or right surface of the cell stack 2 and a front surface of the end plate 3 on the front side from the front end of the connection frame main body 41. Front flange portion 42F extending in the direction of approaching each other, a rear flange portion 42R extending in the direction of approaching each other along the rear surface of the end plate 3 on the rear side from the rear end of the connecting frame main body 41 And a plurality of locking portions 43 provided on the side surface.

  The connection frame 4 of the present embodiment is formed using an aluminum extruded material (aluminum alloy material), and is disposed on the left surface and the right surface of the cell stack 2 with a slight gap, thereby making it possible to It also functions as a heat dissipating member that transfers heat and dissipates heat.

  The front flange portion 42F and the rear flange portion 42R are provided with a plurality of end plate fastening portions 42a fastened to the front end plate 3 or the rear end plate 3 via bolts B1. The end plate fastening portion 42a has a round hole through which the bolt B1 is inserted, and is screwed into the connection frame fastening portion 32a of the end plate 3 on the front side or the end plate 3 on the rear side. The front flange portion 42F and the rear flange portion 42R are fastened to the front end plate 3 or the rear end plate 3. Thereby, the pair of end plates 3 are connected via the connection frame 4. Moreover, conversely speaking, the connecting frame 4 is also fixed in position by the end plate 3.

  The plurality of locking portions 43 are convex portions (or concave portions) extending in the vertical direction on the outer side surface of the connection frame main body 41 and juxtaposed in the front and rear direction via a predetermined interval. Act as. Further, the plurality of locking portions 43 are integrally formed with the connection frame main body 41, and by increasing the surface area of the connection frame 4, the heat dissipation effect of the cell stack 2 by the connection frame 4 is enhanced. Furthermore, the rigidity of the connection frame 4 is improved by providing the plurality of locking portions 43 in the connection frame main body 41.

(Base plate)
As shown in FIGS. 1 to 5, the base plate 5 is fixed to a plate main body 51 extending along the lower surfaces of the cell stack 2 and the end plate 3 and a module support structure (not shown) supporting the battery module 1. A plurality of structure fixing portions 52, a pair of plate wall portions 53 projecting along the left and right faces of the cell stack 2 from the left and right ends of the plate main body 51, and extending along the longitudinal direction; The temperature control device housing 54 recessed in the left and right center of the lower surface, the end plate fastening portion 55 fastened with the base plate fastening portion 31 a of the end plate 3 through the rivet R, and the fixing engaged with the fixing member 7 And a member engaging portion 56.

  The structure fixing portions 52 are provided at the four corners of the plate main body 51 which is rectangular in a plan view, and fixed to the module support structure via a fixing tool such as a bolt. According to such a fixing structure of the battery module 1, since the base plate 5 is fixed to the module supporting structure, the cell pressure restraint reaction force is increased due to the expansion of the cell 21 due to the temperature change and the aged deterioration. Accordingly, even if the end plate 3 moves back and forth, stress transfer to the module support structure can be avoided. Further, by providing the module support structure on the opposite side to the cell stack 2 with the base plate 5 interposed therebetween, the deflection of the base plate 5 can be suppressed.

  The pair of plate wall portions 53 protrudes from the left and right end portions of the plate main body 51 along the left surface and the right surface of the cell stack 2 and extends along the front-rear direction to improve the rigidity of the base plate 5. As a result, positional deviation between the cells 21 caused by the bending of the base plate 5 can be suppressed. Further, since the pair of plate wall portions 53 restricts the lateral movement of the cell stack body 2, the vibration resistance of the battery module 1 can be improved.

  The connection frame main body 41 of the connection frame 4 is disposed on the extension of the plate wall 53 in the vertical direction. Specifically, the upper surface of the plate wall 53 and the lower surface of the connecting frame main body 41 face each other in a contact or proximity state, and the plate wall 53 and the connecting frame main body 41 are arranged to overlap in the vertical direction. . In this case, even when external force in the vertical direction acts on the battery module 1, the force in the direction of bending the base plate 5 is received by the connection frame main body 41 of the connection frame 4. Therefore, the positional deviation of the cells 21 constituting the cell stack 2 can be further suppressed.

  The base plate 5 of the present embodiment is formed using an aluminum extruded material (aluminum alloy material), and is in close contact with the lower surface of the cell stack 2 via the third insulating member 24 to heat the cell stack 2. It also functions as a heat dissipating member that transfers heat and dissipates heat. In the plate main body 51 of the present embodiment, since the temperature control device housing portion 54 is recessed in the lower surface, the vertical dimension of the battery module 1 can be suppressed. In addition, if a temperature control device (not shown) is disposed on the lower surface of the plate main body 51, bending of the base plate 5 can be further suppressed by using the rigidity of the temperature control device while controlling the temperature of the cell stack 2.

  As shown in FIG. 5, the end plate fastening portion 55 has a rivet insertion hole 55a penetrating the plate main body 51 in the vertical direction, and is connected to the base plate fastening portion 31a of the end plate 3 through the collar C and the rivet insertion hole 55a. After inserting the rivet R, the base plate 5 and the end plate 3 are fastened by deforming the tip end of the rivet R and locking it on the step 31 c in the base plate fastening part 31 a.

  The inner diameter of the rivet insertion hole 55a is larger than the outer diameter of the shank of the rivet R, and a gap is formed between the inner periphery of the rivet insertion hole 55a and the outer periphery of the rivet R. Thereby, even if the cell 21 expands due to temperature change or aging, movement of the end plate 3 in the front-rear direction is permitted.

  The fixing member engaging portion 56 is formed on the lower surface side of both ends of the plate main body 51 in the left-right direction, as shown in FIG. 4, and the fixing member 7 is engaged. The engagement surface of the fixing member 7 in the fixing member engaging portion 56 is an inclined surface which becomes lower toward the outside in the left-right direction, and suppresses the detachment of the engaged fixing member 7 to the outside.

(Fourth insulating member 6)
As shown in FIG. 4, the fourth insulating member 6 is an upper surface insulating portion 61 extending in the front-rear direction along the upper surface of the cell stack 2, and side insulating surfaces extending in the front-rear direction along the left or right surface of the cell stack 2. It is an insulating member having an L-shape in which the portion 62 intersects, and is formed of, for example, an insulating resin.

  The lower end portion of the side insulating portion 62 is sandwiched between the upper end portion of the connection frame 4 (connection frame main body 41) and the left surface or the right surface of the cell stack 2 to form the cell stack 2 at the upper end side of the connection frame 4 An insulation gap is secured between the left side and the right side of the In addition, the third insulating member 24 described above includes a main body portion 24a along the lower surface of the cell stack 2 and a pair of upper portions extending along the left or right surface of the cell stack 2 from both end portions of the main body portion 24a in the left-right direction. The rising portion 24b is interposed between the lower end portion of the connection frame 4 (connection frame main body 41) and the left surface or the right surface of the cell stack 2, whereby the connection frame 4 is obtained. An insulating gap is secured between the lower end side and the left or right surface of the cell stack 2.

(Fixing member)
As shown in FIGS. 1 to 4 and 6, the fixing member 7 presses the upper surface of the cell stack 2 from above with the upper surface insulating portion 61 of the fourth insulating member 6, and a base plate It consists of an elastic member 74 provided with the 2nd support part 72 which presses fixed member engaging part 56 of 5 from the lower part, and the connection part 73 which connects the 1st support part 71 and the 2nd support part 72. The first support portion 71 presses the cell stack 2 toward the plate main body 51 of the base plate 5 via the upper surface insulating portion 61 of the fourth insulating member 6. Also, conversely, the second support portion 72 presses the base plate 5 toward the cell stack 2. The first support portion 71 and the second support portion 72 press the cell stack 2 via the upper surface insulating portion 61 and the fixing member engaging portion 56 at substantially the same position in the left-right direction. As a result, the cell stack 2 and the base plate 5 are urged in the direction approaching each other, and are restrained by the fixing member 7 in the vertical direction. When an external force in the vertical direction acts on the battery module 1, the relative position between the cell stack 2 and the base plate 5 is regulated by the fixing member 7, and the force in the direction to bend the base plate 5 is the connecting frame 4 as described above. The connection frame main body 41 of Therefore, positional deviation of the cells 21 constituting the cell stack 2 is suppressed.

  The elastic member 74 is formed using an elastically deformable metal wire as shown in FIG. In the fixing member 7, a plurality of elastic members 74 (for example, wire springs) made of wires are provided in parallel in the front-rear direction via a predetermined interval, and the first support portions 71 of the adjacent elastic members 74 The first connection portions 71 a to be connected and the second connection portions 72 a to connect the second support portions 72 are alternately provided in the front-rear direction. As a result, the plurality of cells 21 can be restrained by the fixing member 7 made of one wire. In the present embodiment, as shown in FIG. 2, the pair of fixing members 7 disposed on the left surface and the right surface of the cell stack 2 are respectively divided into three, but the pair of fixing members 7 are respectively It may be formed of one wire rod, or the number of division may be two or four or more.

  As shown in FIG. 3, two elastic members 74 of this embodiment are disposed for each cell 21, and any one of the connecting portions 71 a and 72 a is disposed in the same cell 21, and the connecting portion 71 a is provided. , 72a are arranged straddling between the adjacent cells 21. In this way, even if the plurality of elastic members 74 are formed of one wire rod, the plurality of cells 21 can be favorably restrained while restricting the positional deviation between the cells 21.

  As shown in FIG. 3, the fixing member 7 is positioned in the front-rear direction by the connection portion 73 of the elastic member 74 being locked to the locking portion 43 of the connection frame 4. The number of the locking portions 43 in the connection frame 4 can be appropriately changed according to the number of divisions of the fixing member 7 or the like, and the locking portion 43 may be formed as a recess instead of a protrusion.

  The present invention is not limited to the above-described embodiment, and appropriate modifications, improvements, and the like can be made. For example, the elastic member 74 as the fixing member 7 is not limited to a wire, but may be a plate (for example, a plate spring).

[Summary]
At least the following aspects are extracted from the embodiment described above. In addition, although the corresponding component etc. are shown in above-described embodiment in parenthesis, it is not limited to this.

(1) a battery module (battery module 1),
A plurality of cells (cells 21) are stacked in a first direction (longitudinal direction), and a first surface (front surface) which is a surface on one end side in the first direction, a surface on the other end side in the first direction A second surface (rear surface), a third surface (left surface) which is a surface on one end side in a second direction (right and left direction) which is a direction orthogonal to the first direction, a surface on the other end side in the second direction A fourth surface (right surface), a fifth surface (upper surface) which is a surface on one end side in a third direction (vertical direction) orthogonal to the first direction and the second direction, and the other end side in the third direction A cell stack (cell stack 2) having a sixth surface (lower surface) which is a surface of
A pair of end plates (end plates 3) disposed on the first surface and the second surface of the cell stack,
A pair of connection frames (connection frame 4) disposed on the third surface and the fourth surface of the cell stack and connecting the pair of end plates;
A base plate (base plate 5) disposed on the sixth surface of the cell stack;
And a pair of fixing members (fixing members 7) for urging the cell stack and the base plate in directions approaching each other,
The base plate is
A plate body (plate body 51) extending along the sixth surface of the cell stack;
At both end portions of the plate main body in the second direction, it projects from the mounting surface on which the cell stack is mounted along the third surface and the fourth surface of the cell stack, and along the first direction. And a pair of plate walls (plate wall 53) extending;
The battery module, wherein the connection frame is disposed on an extension of the plate wall in the third direction.

  According to the battery module of (1), since the base plate has the plate wall portions erected at both ends of the plate main body, the rigidity of the base plate is improved. Thereby, the bending of the base plate can be suppressed, and positional deviation between cells constituting the cell stack can be suppressed. Further, since the connecting frame connecting the pair of end plates is disposed on the extension of the plate wall in the third direction, the base plate is bent even when the battery module receives an external force in the third direction. The directional force is received by the connecting frame. Therefore, positional deviation between cells constituting the cell stack can be further suppressed.

(2) The battery module according to (1), wherein
The fixing member includes a first support portion (first support portion 71) supporting the fifth surface of the cell stack, a second support portion (second support portion 72) supporting the base plate, and the first support portion. A connecting portion (connecting portion 73) for connecting the supporting portion and the second supporting portion;
The fixing member is an elastic member (elastic member 74) in which the first support portion, the second support portion, and the connection portion are integrally formed.

  According to the battery module of (2), the fixing member is made of an elastic member and can be deformed as a whole. Therefore, the spring constant can be set low and the variation of the load can be suppressed.

(3) The battery module according to (2), wherein
The fixing member is a wire.

  According to the battery module of (3), by using the wire material for the fixing member, it is possible to form a spring at low weight and at low cost.

(4) The battery module according to (2) or (3), wherein
The fixing member is formed by continuously forming a plurality of the elastic members.
The connection part (the 1st connection part 71a, the 2nd connection part 72a) which connects the adjacent said elastic member is arrange | positioned over the said adjacent cell.

  According to the battery module of (4), since a plurality of cells can be restrained by one wire rod, cost reduction can be achieved. Moreover, since the elastic members connected by the connection part can be deformed independently to some extent, variation in the dimension in the third direction of the cells can be absorbed.

(5) The battery module according to (4), wherein
The connection frame is provided with a locking portion (locking portion 43) formed of a convex portion or a concave portion on the outer side surface,
The fixing member is positioned by the locking portion.

  According to the battery module of (5), the connection frame makes it possible to position the fixing member.

(6) The battery module according to (5), wherein
The connection frame is made of an aluminum alloy material, and a connection frame main body (connection frame main body 41) is integrally formed with the locking portion.

  According to the battery module of (6), since the connection frame is made of the aluminum alloy material, the cooling effect of the cell stack can be obtained. Further, since the connection frame main body is integrally formed with the locking portion for positioning the fixing member, the cooling effect is enhanced by the concave portion or the convex portion of the locking portion.

(7) The battery module according to any one of (1) to (6), wherein
A structure or a temperature control device for supporting the battery module is provided on the opposite side of the base plate to the cell stack.

  According to the battery module of (7), the structure or the temperature control device for supporting the battery module is provided on the opposite side of the base plate to the cell stack, so that the deformation of the base plate can be further suppressed. It becomes.

DESCRIPTION OF SYMBOLS 1 battery module 2 cell laminated body 21 cell 3 end plate 4 connecting frame 41 connecting frame main body 43 locking portion 5 base plate 51 plate main body 53 plate wall portion 7 fixing member 71 first support portion 71 a first connecting portion (connecting portion)
72 second support portion 72a second connection portion (connection portion)
73 connection 74 elastic member

Claims (7)

A battery module,
A plurality of cells are stacked in a first direction, and a first surface which is a surface on one end side in the first direction, a second surface which is a surface on the other end side in the first direction, and the first direction The third surface which is the surface on the one end side in the second direction which is the orthogonal direction, the fourth surface which is the surface on the other end side in the second direction, the third direction which is orthogonal to the first direction and the second direction A cell stack having a fifth surface which is a surface on one end side and a sixth surface which is a surface on the other end side in the third direction;
A pair of end plates disposed on the first surface and the second surface of the cell stack;
A pair of connecting frames disposed on the third surface and the fourth surface of the cell stack and connecting the pair of end plates;
A base plate disposed on the sixth surface of the cell stack;
And a pair of fixing members for urging the cell stack and the base plate in directions approaching each other,
The base plate is
A plate body extending along the sixth surface of the cell stack;
At both end portions of the plate main body in the second direction, it projects from the mounting surface on which the cell stack is mounted along the third surface and the fourth surface of the cell stack, and along the first direction. And a pair of extending plate walls;
The battery module, wherein the connection frame is disposed on an extension of the plate wall in the third direction. The battery module according to claim 1,
The fixing member is a first supporting portion supporting the fifth surface of the cell stack, a second supporting portion supporting the base plate, and a connecting portion connecting the first supporting portion and the second supporting portion. And
The battery module, wherein the fixing member is an elastic member in which the first support portion, the second support portion, and the connection portion are integrally formed. The battery module according to claim 2,
The battery module, wherein the fixing member is a wire. It is a battery module of Claim 2 or 3, Comprising:
The fixing member is formed by continuously forming a plurality of the elastic members.
The connection part which connects the said adjacent elastic member is a battery module which is arrange | positioned over the said adjacent cell. It is a battery module of Claim 4, Comprising:
The connection frame is provided with a locking portion formed of a convex portion or a concave portion on the outer side surface,
The battery module, wherein the fixing member is positioned at the locking portion. The battery module according to claim 5, wherein
The battery module, wherein the connection frame is made of an aluminum alloy material, and a connection frame main body is integrally formed with the locking portion. It is a battery module of any one of Claims 1-6, Comprising:
A battery module, wherein a structure or a temperature control device for supporting the battery module is provided on the opposite side of the base plate to the cell stack.

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