WO2019031170A1

WO2019031170A1 - Battery module and vehicle equipped with same

Info

Publication number: WO2019031170A1
Application number: PCT/JP2018/026899
Authority: WO
Inventors: 憲吾石橋; 伸一三堀; 忍寺内
Original assignee: 三洋電機株式会社
Priority date: 2017-08-07
Filing date: 2018-07-18
Publication date: 2019-02-14
Also published as: JP2020184405A

Abstract

The purpose of the present invention is to obtain a sufficient strength of an end plate while reducing the weight thereof. This battery module is provided with: a battery stack (2) comprising a plurality of rectangular battery cells (1) stacked in a thickness direction; a pair of end plates (3) arranged at both end surfaces in the stacking direction of the battery stack (2); and bind bars (4) which are arranged at both side surfaces of the battery stack (2) and bind the pair of end plates (3). Each of the end plates (3) is provided with a metal plate (11) opposing each end surface of the battery stack (2), a vertical pipe (12) extending vertically, and a lateral pipe (13) extending horizontally, the vertical pipe (12) and the lateral pipe (13) being arranged on the outside of the metal plate (11) and fixed in positions intersecting each other. The bind bars (4) are connected to both ends of the lateral pipe (13).

Description

Battery module and vehicle equipped with the same

The present invention relates to a battery module formed by connecting end plates formed at both ends of a battery stack in which a plurality of rectangular battery cells are stacked by a bind bar, and a vehicle equipped with the battery module.

A typical battery module includes a battery stack including a plurality of rectangular battery cells, a pair of end plates disposed on both end surfaces of the battery stack, and a bind bar connecting the pair of end plates (see FIG. Patent Document 1). In this battery module, expansion of rectangular battery cells constituting the battery stack can be suppressed by restraining the battery stack with the end plate and the bind bar.
On the other hand, in recent years, a battery module having high energy density per volume and high energy density per weight is required, and a rectangular battery cell constituting the battery module also has a high energy density per volume and a high energy density per weight It is desirable to adopt

International Publication No. 2012/057322

In the rectangular battery cell, when it is intended to increase the energy density per unit volume and the energy density per unit weight, the dimensional change due to charge and discharge and deterioration tends to be large. In order to suppress the expansion of the rectangular battery cell in which the dimensional change due to charge and discharge and deterioration is large, it is necessary to restrain the rectangular battery cell with a relatively large force.
However, in the battery module of Patent Document 1, the end plate is composed of a plastic main body and a metal plate such as aluminum, and when a large force is applied, the main body is damaged or the metal plate is deformed. There is a risk of If the end plate is broken or deformed, the expansion of the rectangular battery cell can not be suppressed.

The present invention has been developed for the purpose of solving the above-mentioned drawbacks, and one of the objects of the present invention is to provide a technology for suppressing the expansion of a rectangular battery cell by providing an end plate having sufficient strength. It is to provide.

A battery module according to an embodiment of the present invention includes a battery stack 2 formed by stacking a plurality of rectangular battery cells 1 in the thickness direction, and a pair of end plates disposed on both end surfaces of the battery stack 2 in the stacking direction. 3 and a bind bar 4 disposed on both sides of the battery stack 2 and fastening a pair of end plates 3. The end plate 3 is disposed outside the metal plate 11 and the metal plate 11 disposed to face the end face of the battery stack 2, and fixed in a posture to cross each other, extending in the vertical direction A binding bar 4 is connected to both ends of the horizontal pipe 13, which comprises a pipe 12 and a horizontal pipe 13 extending in the horizontal direction.

Furthermore, the vehicle equipped with the battery module having the components of the above-described embodiment includes the battery module 10, the traveling motor 93 supplied with power from the battery module 10, the battery module 10, and the motor 93. And a wheel 97 driven by a motor 93 to drive the vehicle main body 90.

According to the above-described battery module, the end plate is formed of the metal plate disposed to face the end face of the battery stack, and the longitudinal and horizontal pipes fixed in a posture to cross each other, thereby forming a cylindrical shape. The strength of the end plate can be enhanced by taking advantage of the advantages that the pipe has, that is, the characteristic of having a large cross section coefficient and excellent rigidity, and by using the longitudinal pipe and the horizontal pipe consisting of cylindrical pipes, The overall weight can be reduced. In particular, excellent rigidity can be realized by fixing the vertical pipe extending in the vertical direction and the horizontal pipe extending in the horizontal direction in a cross state. Therefore, according to the above configuration, it is possible to provide an end plate that has sufficient strength and can realize weight reduction, and can effectively suppress expansion of the prismatic battery cell.

It is a perspective view showing a battery module concerning Embodiment 1 of the present invention. It is a disassembled perspective view of the battery module shown in FIG. It is an enlarged vertical sectional view of the end plate of the battery module shown in FIG. It is an expansion horizontal sectional view of the end plate of the battery module shown in FIG. It is an expansion horizontal sectional view showing another example of an end plate. FIG. 2 is a block diagram showing an example in which a battery module is mounted on a hybrid vehicle traveling by an engine and a motor. It is a block diagram which shows the example which mounts a battery module in the electric vehicle which drive | works only by a motor.

First, one focus point of the present invention will be described. In a battery module provided with a large number of rectangular battery cells, end plates are disposed on both end faces of a battery stack in which a plurality of rectangular battery cells are stacked, and a pair of end plates are connected by a bind bar. It fixes in the state pressurized in a lamination direction. In this battery module, since both ends of the battery stack are fixed in a pressurized state by a pair of end plates, sufficient strength is required of the end plates. In the end plate, the rectangular battery cells to be charged and discharged expand and receive cell reaction force from the inner surface. Since the end plate is pressed from the inner surface by the battery stack that expands, it receives a cell reaction force that is proportional to the product of the area of the battery stack and the pressure that the battery stack presses. Therefore, in a rectangular battery having a large dimensional change due to charging and discharging, a cell reaction force having a size corresponding to the amount of expansion acts on the end plate. The cell reaction force acting on the end plate is extremely large, for example, several tons in a battery module for a power supply for driving a traveling motor of a vehicle. Therefore, in order to realize a battery module with a high energy density, it is necessary to provide an end plate having sufficient strength such that deformation can be suppressed even when such an extremely large force is applied.

On the other hand, since the end plate is required to have both strength and weight reduction characteristics, the plastic is formed into a thick plate shape, and a metal plate such as aluminum is laminated on the outside, or the whole is aluminum etc. And molded with plastic. Since these end plates have low plastic part strengths and metal plates do not have high strength against bending deformation, they can be used in battery modules with small cell reaction force, but are sufficient in battery modules with large cell reaction force Unable to achieve strength. An end plate which is not strong enough is deformed by a strong cell reaction force. The deforming end plate causes the relative position of the rectangular battery cells fixed in the pressurized state to change. In a rectangular battery cell, a thick metal plate bus bar is fixed to the electrode terminal and connected in series or in parallel via the bus bar. Therefore, if a shift occurs in the relative position, the connecting portion between the electrode terminal and the bus bar can not be forced Distortion force works. The strain causes damage to the connection portion between the electrode terminal and the bus bar, and also causes damage to the connection portion between the electrode terminal and the outer case of the rectangular battery cell. The relative positional deviation of the rectangular battery cells can be improved by making the end plates sufficiently strong. The end plate can realize sufficient strength by making the whole into a metal block such as iron alloy.

However, the end plate of this structure is extremely heavy, and as a result, the energy density of the battery module is lowered and it can not be put into practical use. The end plate is required to have a high strength while reducing the weight, but the weight reduction and the strength are opposite properties to each other, and it was extremely difficult to realize both. On the other hand, the end plate which utilizes the rigidity of the cylindrical shape effectively can be reduced in weight while achieving high strength.

The battery module of one aspect of the present invention may be identified by the following configuration. The battery module includes a battery stack 2 formed by stacking a plurality of rectangular battery cells 1 in the thickness direction, a pair of end plates 3 disposed on both end surfaces of the battery stack 2 in the stacking direction, and a battery stack And a bind bar 4 disposed on both sides of the two and fastening a pair of end plates 3. The end plate 3 is disposed outside the metal plate 11 and the metal plate 11 disposed to face the end face of the battery stack 2, and fixed in a posture to cross each other, extending in the vertical direction A binding bar 4 is connected to both ends of the horizontal pipe 13, which comprises a pipe 12 and a horizontal pipe 13 extending in the horizontal direction.

The end plate 3 has a plate portion 11A having an outer shape substantially equal to the end face shape of the battery stack 2 and a both-sides bending in the stacking direction of the rectangular battery cell 1 from both side edges in the width direction of the plate portion 11A. Both ends of the horizontal pipe 13 can be fixed to the both-sides bent pieces 11B by providing the pieces 11B.
According to the above configuration, since the metal plate is provided with the bent pieces on both sides of the plate portion, it is possible to realize strong bending strength in the vertical direction, and to fix the both ends of the horizontal pipe to the bent pieces on both sides. Thus, while making the metal plate and the horizontal pipe into an integral structure, the cell reaction force acting on the metal plate can be reliably supported by the bind bar.

In addition, the battery module further includes a fixing pin 5 for fixing the bind bar 4 on the side surface of the end plate 3, the horizontal pipe 13 has connection holes 13A of the fixing pin 5 at both ends, and the fixing pin 5 is The bind bar 4 can be connected to the end plate 3 by being inserted through the bind bar 4 into the connection hole 13 A of the horizontal pipe 13.
According to the above configuration, the above battery module connects the fixing pin passing through the binding bar to the end of the horizontal pipe and fixes the binding bar to the end plate, so the horizontal pipe can be used as a fixing pin fixing tool While, the binding bar and the end plate can be firmly connected as an integral structure.

Further, the battery module can be fixed by screwing the bolt 5A into the female screw hole 13a with the fixing pin 5 as the bolt 5A and the connection hole 13A of the horizontal pipe 13 as the female screw hole 13a.
Since the above battery module fixes the bind bar to the end plate by screwing the bolt into the female screw hole of the horizontal pipe, it makes the bind bar and the end plate rigid while using the horizontal pipe together with the nut for screwing the bolt and fixing. There is a feature that can be fixed to the integral structure. Furthermore, the structure used in combination with a nut for screwing in and securing a horizontal pipe also realizes a feature in which the female screw hole can be elongated and the bolt can be deeply screwed into the female screw hole and firmly fixed.

Furthermore, the battery module further includes a fixing bolt 6 for fixing the end plate 3 to the base plate 9 disposed on the bottom side of the battery module, and the fixing bolt 6 is inserted through the vertical pipe 12 to the base plate 9 It can be fixed.
According to the above configuration, the fixing bolt is inserted into the vertical pipe, and the end plate is fixed to the base plate disposed on the bottom side of the battery module. Therefore, the vertical pipe configured to reinforce the end plate is The battery module can be efficiently coupled to the base plate while reducing the manufacturing cost without providing a dedicated insertion member as a member for insertion.

In addition, the end plate 3 can connect the plurality of vertical pipes 12 and the plurality of horizontal pipes 13 in the form of parallel crosses.
According to the above configuration, by connecting the plurality of longitudinal pipes and the plurality of horizontal pipes in a well-girder shape, excellent strength can be realized and the rigidity of the end plate can be enhanced.

Further, in the battery module, the vertical pipe 12 can be disposed closer to the battery stack 2 than the horizontal pipe 13.
According to the above configuration, the cell reaction force that the metal plate receives from the battery stack acts on the horizontal pipe through the vertical pipe, so the cell reaction force acting on the end plate is dispersed to the metal plate, the vertical pipe, the horizontal pipe, and While being applied to the bind bar in a straight line, the cell reaction force can be stably received.

Furthermore, the end plate 3 can fix and fix the longitudinal pipe 12 and the horizontal pipe 13 which intersect each other at the intersection.
According to the above configuration, the end plates can be thinned by overlapping the longitudinal pipes and the horizontal pipes crossing each other at the intersections. Therefore, the outer shape of the entire battery module can be reduced.

Furthermore, in the battery module, at the intersection of the vertical pipe 12 and the horizontal pipe 13, a notch 14 along the outer shape of the vertical pipe 12 is provided on the surface of the horizontal pipe and at a position facing the vertical pipe 12. The vertical pipe 12 can be fixed to the horizontal pipe 13 by aligning the surface of the vertical pipe 12 with 14.
According to the above configuration, at the intersection of the vertical pipe and the horizontal pipe, a notch is provided on the surface of the horizontal pipe, and the outer surface of the vertical pipe is aligned and fixed to the notch, so the surface of the vertical pipe is notched It is possible to overlap the vertical pipe and the horizontal pipe without. Therefore, the end plate can be thinned by reducing the center-to-center distance with the horizontal pipe while maintaining the rigidity of the vertical pipe. In particular, in the structure in which the fixing bolt is inserted into the vertical pipe, the fixing bolt can be smoothly inserted into the vertical pipe because it can be fixed to the horizontal pipe without cutting out the vertical pipe.

Furthermore, in the battery module, the vertical pipe 12 and the horizontal pipe 13 can be cylindrical metal pipes.
According to the above configuration, by making the vertical pipe and the horizontal pipe into a cylindrical metal pipe, the section coefficient can be increased, and the weight can be reduced while increasing the strength.

Furthermore, in the battery module, the vertical pipe 12 and the horizontal pipe 13 can be made of iron or iron alloy.
According to the above configuration, by making the vertical pipe and the horizontal pipe of iron or iron alloy, generally used iron or iron alloy pipe can be used, and excellent strength can be realized while reducing the manufacturing cost. In particular, by using a hollow pipe while using iron having a large specific gravity as a material, it is possible to realize excellent strength by effectively using the rigidity of iron while reducing the overall weight.

Furthermore, according to the vehicle equipped with the battery module according to one aspect, the battery module of any of the above, the traveling motor 93 supplied with power from the battery module, and the battery module and motor 93 are mounted. A vehicle body 90 and wheels 97 driven by a motor 93 to travel the vehicle body 90 can be provided.

Hereinafter, embodiments of the present invention will be described based on the drawings. However, the embodiments shown below are exemplifications for embodying the technical idea of the present invention, and the present invention is not limited to the following. Further, the present specification does not in any way specify the members described in the claims to the members of the embodiment. In particular, the dimensions, materials, shapes, relative arrangements, and the like of the constituent members described in the embodiments are not intended to limit the scope of the present invention to the scope thereof unless specifically stated otherwise, and merely illustrative examples It is only Note that the size, positional relationship, and the like of the members shown in each drawing may be exaggerated for the sake of clarity. Further, in the following description, the same names and reference numerals indicate the same or the same members, and the detailed description will be appropriately omitted. Furthermore, each element constituting the present invention may be configured such that a plurality of elements are constituted by the same member and one member is used in common as a plurality of elements, or conversely the function of one member is realized by a plurality of members It can be shared and realized. In addition, the contents described in some examples and embodiments may be applicable to other examples and embodiments. Furthermore, in the specification, the vertical direction is specified in the drawings.

(Embodiment 1)
1 to 4 show the battery module according to the first embodiment. 1 is a perspective view of the battery module, FIG. 2 is an exploded perspective view of the battery module, FIG. 3 is a vertical sectional view of the end of the battery module cut in a vertical plane, and FIG. 4 is an end of the battery module The horizontal sectional view cut in the horizontal surface is shown, respectively.

A battery module 10 shown in these figures is a battery stack 2 in which a plurality of rectangular battery cells 1 are stacked with a separator 18 of insulating material interposed therebetween, and both end surfaces of the battery stack 2. It comprises a pair of end plates 3 held in a fixed position from the surface and a bind bar 4 connecting the pair of end plates 3. Furthermore, the battery module shown in FIGS. 1 and 2 fixes the bolt 5A of the fixing pin 5 for fixing the bind bar 4 to the end plate 3 and the end plate 3 to the base plate 9 disposed on the bottom side of the battery module 10. For fixing bolt 6 is provided. Furthermore, as shown in FIG. 2, the battery module 10 may have a configuration in which the insulating sheet 16 is interposed between each bind bar 4 and the battery stack 2, and the battery stack 2 and the end plate 3 It is good also as composition provided with the bottom plate 17 which insulates these also to the bottom.

The above battery module 10 has an elongated box shape as a whole, as shown in FIG. 1, and a large number of rectangular battery cells 1 are stacked to form a battery stack 2, and the battery stack 2 is endplate 3 from both end faces in the stacking direction. , And the end plates 3 at both ends are connected by the bind bar 4 to fix the battery stack 2 in a pressurized state. The battery stack 2 connects the stacked rectangular battery cells 1 in series, in parallel, or in series and parallel via bus bars (not shown) of metal plates.

(Square battery cell 1)
The rectangular battery cell 1 is a rectangular battery which is wider than the thickness, that is, thinner than the width as shown in the figure, and is stacked in the thickness direction to form a battery stack 2. The rectangular battery cell 1 is a lithium ion secondary battery. However, the prismatic battery cell may be any rechargeable secondary battery such as a nickel hydrogen battery, a nickel cadmium battery, and the like. In the rectangular battery cell 1, the positive and negative electrode plates are accommodated together with the electrolytic solution in the sealed case having an enclosure. The outer can is formed by pressing a metal plate such as aluminum or aluminum alloy into a square shape, and the opening is airtightly sealed by a sealing plate. The sealing plate is made of the same aluminum or aluminum alloy as the case, and has positive and negative electrode terminals fixed at both ends. Furthermore, the sealing plate is provided with a gas discharge valve between the positive and negative electrode terminals.

The plurality of rectangular battery cells 1 are stacked such that the thickness direction of each of the rectangular battery cells 1 is the stacking direction, thereby forming a battery stack 2. In the rectangular battery cell 1, terminal surfaces provided with positive and negative electrode terminals are disposed on the same plane, and a plurality of rectangular battery cells 1 are stacked to form a battery stack 2.

(Separator 18)
As shown in FIG. 3 and FIG. 4, the battery stack 2 sandwiches the separator 18 between the stacked rectangular battery cells 1. The illustrated separator 18 is made of an insulating material in the form of a thin plate or sheet. The separator 18 shown in the figure is in the form of a plate having substantially the same size as the opposing surface of the rectangular battery cell 1, and the separator 18 is stacked between adjacent rectangular battery cells 1 to form adjacent rectangular battery cells 1. Is insulated. A second spacer may be disposed between adjacent rectangular battery cells 1 separately from the separator 18. The rectangular battery cell 1 can be cooled by using a spacer having a shape in which a flow path of cooling gas is formed between the rectangular battery cell 1 and the spacer. The surface of the rectangular battery cell 1 can also be coated with an insulating material. For example, the surfaces of the outer cans may be heat welded together with a shrink tube such as a PET resin, except for the electrode portions of the rectangular battery cells.

(Battery stack 2)
In the battery stack 2, a metal bus bar (not shown) is connected to the positive and negative electrode terminals of the adjacent rectangular battery cells 1, and the plurality of rectangular battery cells 1 are connected in series or in parallel or in series with the bus bar. Connected in parallel. In the battery stack 2 shown in the figure, eighteen rectangular battery cells 1 are connected in series. However, the present invention does not specify the number of rectangular battery cells constituting the battery stack and the connection state thereof.

In the battery stack 2, the end plate 3 is disposed with the end face spacer 19 at both end faces. The end face spacer 19 is disposed between the battery stack 2 and the end plate 3 to insulate the end plate 3 from the battery stack 2 as shown in FIG. The end face spacer 19 can be made of the same material as the separator 18 described above.

(End plate 3)
The pair of end plates 3 disposed at both ends of the battery stack 2 is connected to the bind bar 4 and holds the battery stack 2 in a pressurized state, so that the cell reaction force is received by the expansion of the rectangular battery cell 1 . The end plate 3 shown in FIGS. 1 to 4 is disposed outside the metal plate 11 and the metal plate 11 disposed to face the end face of the battery stack 2 in order to realize the strength to withstand the cell reaction force. It comprises a vertically extending vertical pipe 12 and a horizontally extending horizontal pipe 13 which are fixed in such a manner as to cross each other. The metal plate 11 is manufactured by pressing a plate made of metal such as iron or iron alloy. The vertical pipe 12 and the horizontal pipe 13 are also metal pipes such as iron and iron alloy, and the vertical pipe 12 and the horizontal pipe 13 in the figure are hollow cylindrical pipes whose outer shapes are cylindrical.

(Metal plate 11)
The metal plate 11 is manufactured by pressing a plate material of iron or iron alloy into a shape in which a bent piece formed by bending at right angles around a square is provided. The metal plate 11 processed into this shape connects the both-sides bending pieces 11B to both side edges of the rectangular plate portion 11A having the end face shape of the battery stack 2, in other words, the outer shape approximately equal to the outer shape of the rectangular battery cell 1. In this shape, the both-sides bent pieces 11B are connected to both sides in the width direction of the plate portion 11A.

The both-sides bent pieces 11B are in the vertical plane and project from the side edges of the plate portion 11A in the stacking direction of the rectangular battery cells 1. The both-sides bent pieces 11B connect the bind bars 4 arranged on the both sides, and also become reinforcing ribs to improve the bending strength of the end plate 3 in the vertical direction. In the metal plate 11 manufactured by bending a flat plate material, both bent pieces 11B formed on both sides are disposed in parallel to each other, with the bending angle being substantially perpendicular. Furthermore, the both-sides bending pieces 11B are provided with the through holes 11 b of the bolts 5A which are the fixing pins 5 of the bind bar 4. The battery module 10 shown in FIGS. 2 and 4 is fixed by the bolts 5A arranged at the two upper and lower ends of the bind bar 4 so that the two through holes 11b are separated from each other in the upper and lower bent pieces 11B. It is provided.

The both-sides bending piece 11B shown in the horizontal cross sectional view of FIG. 4 fixes the horizontal pipe 13 to the metal plate 11 by inserting the end of the horizontal pipe 13 into the through hole 11b. The through hole 11 b through which the horizontal pipe 13 passes has an inner diameter substantially equal to the outer diameter of the horizontal pipe 13 but slightly larger. Since the both side bent pieces 11B penetrate and fix the horizontal pipe 13, the width of the both side bent pieces 11B is made larger than the outer diameter of the side pipe 13, and the side pipe 13 is fixed to the both side bent pieces 11B. It is made to penetrate. In the battery module 10 of FIG. 4, the end of the horizontal pipe 13 penetrates the both-sides bent pieces 11B and protrudes from the both-sides bent pieces 11B on both sides. The protruding portion 13B of the horizontal pipe 13 protruding from the both side bent pieces 11B is guided by the connecting recess 7A provided in the reinforcing portion 7 fixed to the inner surface of the bind bar 4 as described later in detail. Is connected to the bind bar 4.

The reinforcing portion 7 shown in FIG. 4 has the connecting recess 7A as a through hole, and the protrusion 13B of the horizontal pipe 13 is inserted into the through hole to connect the bind bar 4 to the end plate 3. The connecting recess 7A into which the horizontal pipe 13 is inserted has an inner diameter substantially equal to the outer diameter of the horizontal pipe 13, but slightly larger. In the battery module 10 of FIG. 4, the projecting portion 13 B of the horizontal pipe 13 penetrates the reinforcing portion 7 without penetrating the binding bar 4 to connect the binding bar 4 to the end plate 3. In this connection structure, the bind bar 4 is fixed to the end plate 3 by sandwiching the bind bar 4 between the bolt head 5 a of the bolt 5 A and the horizontal pipe 13.

Although not shown, the battery module 10 may have a structure in which the protrusion 13B of the horizontal pipe 13 penetrates the bind bar 4. In this connection structure, the protrusion 13 B of the horizontal pipe 13 is inserted into the connection recess 7 A of the reinforcement 7 and the stop hole 4 a of the bind bar 4, and the bind bar 4 is connected to the end plate 3. Therefore, the inner diameter of the locking hole 4a of the bind bar 4 is made larger than the outer diameter of the horizontal pipe 13, and a clearance is provided between the horizontal pipe 13 and the locking hole 4a. The end plate 3 can be moved slightly.

The above-mentioned end plate 3 has both ends of the horizontal pipe 13 penetrated to the both side bent pieces 11B and protrudes from both sides, but the side pipe is bent on both sides without causing both ends to protrude from the both side bent pieces It can also be fixed to a piece of music. This end plate fixes the inner surface of the bind bar in contact with the side surfaces as flat surfaces without projecting both ends of the horizontal pipe from both side surfaces.

(Vertical pipe 12, horizontal pipe 13)
The vertical pipe 12 and the horizontal pipe 13 are metal pipes such as iron or iron alloy, and are fixed so that the plurality of vertical pipes 12 extending in the vertical direction and the plurality of horizontal pipes 13 extending in the horizontal direction cross each other. doing. The vertical pipe 12 has a length equal to the vertical width of the metal plate 11, and has an insertion hole 12A which penetrates the inside up and down. The horizontal pipe 13 has a length substantially equal to the horizontal width of the metal plate 11, and is precisely longer than the horizontal width of the metal plate 11, and both ends project from both side surfaces of the metal plate.

The end plate 3 shown in FIGS. 1 and 2 is formed into a double-girder shape by combining two vertical pipes 12 arranged apart from each other on the left and right and two horizontal pipes 13 arranged apart from one another vertically. It is connected. Thus, the rigidity of the end plate 3 is enhanced by connecting the plurality of vertical pipes 12 and the horizontal pipes 13 in a well-girder shape. However, the end plate can be fixed in a posture in which three or more longitudinal pipes or three or more horizontal pipes are intersected.

In the end plate 3 shown in the figure, the vertical pipe 12 is disposed closer to the battery stack 2 than the horizontal pipe 13. In the end plate 3, the vertical pipe 12 is disposed outside the plate portion 11A, and both ends of the horizontal pipe 13 disposed outside the vertical pipe 12 are provided on both side edges of the plate portion 11A. The vertical pipe 12 and the horizontal pipe 13 are disposed at fixed positions of the metal plate 11 while being fixed to 11B. The end plate 3 applies the cell reaction force received from the battery stack 2 to the bind bar 4 in a linear manner while acting on the plate portion 11A of the metal plate 11, the vertical pipe 12, and the horizontal pipe 13 in this order. I can accept the power.

The two vertical pipes 12 disposed adjacent to the plate portion 11A are disposed at predetermined intervals, and the two cell reaction forces that the left and right middle portions of the plate portion 11A receive from the battery stack 2 are provided. The horizontal pipe 13 is operated via the vertical pipe 12 of FIG. Furthermore, the cell reaction force that the side portions of the plate portion 11A receive from the battery stack 2 acts on the horizontal pipe via the both-sides bent pieces 11B connected to the side edges of the plate portion 11A. As a result, the cell reaction force acting on the entire plate portion 11A is received by the horizontal pipe 13 while being dispersed to the vertical pipe 12 and the both side bent pieces 11B.

The two horizontal pipes 13 arranged outside the vertical pipe 12 are arranged at predetermined intervals in the upper and lower direction, and the cell reaction force acting through the vertical pipe 12 and the both-side bent pieces 11B is It is made to act uniformly and to receive on the horizontal pipe 13 arrange | positioned at intervals. The cell reaction force acting on the horizontal pipe is linearly applied in the stacking direction of the rectangular battery cells 1 to the bind bars 4 connected to both ends of the horizontal pipe 13.

Furthermore, the end plate 3 shown in FIG. 3 and FIG. 4 is fixed by overlapping the longitudinal pipe 12 and the transverse pipe 13 which intersect each other at the intersection. In the end plate 3 shown in the figure, in order to fix the vertical pipe 12 and the horizontal pipe 13 in a state where they overlap with each other, a notch 14 is formed in one or both of the intersections of the vertical pipe 12 and the horizontal pipe 13. It is provided. In the end plate 3 shown in the figure, a notch 14 along the outer shape of the vertical pipe 12 is provided on the surface of the horizontal pipe 13 at a position facing the vertical pipe 12. The end plate 3 fixes the longitudinal pipe 12 to the lateral pipe 13 by aligning the outer peripheral surface of the longitudinal pipe 12 with the notch 14 provided in the lateral pipe 13. As described above, the structure in which the intersecting vertical pipe 12 and the horizontal pipe 13 overlap at the intersection can make the end plate 3 thinner.

The vertical pipe 12 and the horizontal pipe 13 can adjust the overlap amount by adjusting the notch depth (h) of the notch 14. The end plate 3 can be made thinner by increasing the overlap amount between the vertical pipe 12 and the horizontal pipe 13, but the rigidity is reduced. Therefore, the vertical pipe 12 and the horizontal pipe 13 increase the overlap amount within a range in which the decrease in rigidity is acceptable. The overlap amount is designed to be an optimal value according to the outer diameter and thickness of the vertical pipe 12 and the horizontal pipe 13. In the end plate 3 shown in the figure, the thickness of the horizontal pipe 13 in which the notch portion 14 is provided is made larger than the thickness of the vertical pipe 12 to increase the rigidity of the vertical pipe 12 and the horizontal pipe 13 fixed in the cross state. There is.

Here, the outer diameter of the vertical pipe 12 is R, the outer diameter of the horizontal pipe 13 is r, the thickness of the vertical pipe 12 is t, the thickness of the horizontal pipe 13 is s, and the center-to-center distance between the vertical pipe 12 and the horizontal pipe 13 The notch depth h is h = (R + r) / 2-d, where d is the notch depth of the notch h.
Here, the notch depth h can be preferably in a range satisfying h ≦ rs, in the structure where the horizontal pipe 13 is provided with the notch portion 14.

Furthermore, the end plate 3 shown in FIG. 5 has a structure in which the notch depth h of the notch 14 provided in the horizontal pipe 13 is smaller than the thickness t of the vertical pipe 12. Thus, in the structure in which the notch depth h of the notch 14 provided in the horizontal pipe 13 is smaller than the thickness t of the vertical pipe 12, the outer peripheral surface of the vertical pipe 12 intrudes into the inner surface of the horizontal pipe 13. You can prevent Therefore, excellent strength can be realized without reducing the rigidity of the horizontal pipe 13.

As described above, at the intersection of the vertical pipe 12 and the horizontal pipe 13, the notch 14 is provided on the surface of the horizontal pipe 13, and the outer surface of the vertical pipe 12 is aligned and fixed to the notch 14. The longitudinal pipe 12 and the horizontal pipe 13 can overlap without cutting the surface of the pipe 12. Therefore, the end plate 3 can be made thinner by reducing the center-to-center distance with the horizontal pipe 13 while maintaining the rigidity of the vertical pipe 12. In particular, in the structure in which the fixing bolt 6 is inserted into the vertical pipe 12, the fixing bolt 6 can be smoothly inserted into the vertical pipe 12 because it can be fixed to the horizontal pipe 13 without cutting out the vertical pipe 12.

The notch can also be provided in the vertical pipe. However, when providing a notch in the vertical pipe, if the notch depth h of the notch is larger than the thickness t of the vertical pipe, the outer peripheral surface of the horizontal pipe intrudes into the inside of the insertion hole of the vertical pipe. When inserting a bolt, it can not be smoothly inserted. Therefore, the notch depth h of the notch provided in the vertical pipe is preferably smaller than the thickness t of the vertical pipe. However, in the battery module in which the fixing bolt is not inserted into the vertical pipe of the end plate, the notch depth h of the notch provided in the vertical pipe may be larger than the thickness t of the vertical pipe. In this case, the cutting depth h can be preferably provided in the range of h ≦ R−t.

Furthermore, it is also possible to provide notches at both of the intersections, i.e. on the respective opposite surfaces, of the longitudinal and transverse pipes which are fixed to one another in an overlapping manner. This structure makes the notch depth of the notch provided in the vertical pipe smaller than the thickness t of the vertical pipe and makes the notch depth of the notch provided in the horizontal pipe smaller than the thickness s of the horizontal pipe Thus, the amount of overlap between the vertical pipe and the horizontal pipe can be increased without invading the horizontal pipe inside the vertical pipe and without invading the vertical pipe inside the horizontal pipe. This structure is characterized in that the end plate can be made thinner by increasing the amount of overlap without reducing the rigidity of the vertical and horizontal pipes.

However, the vertical pipe and the horizontal pipe can be fixed without overlapping the intersection. This structure joins the vertical pipe and the horizontal pipe at the junction of the intersection.

The vertical pipe 12 and the horizontal pipe 13 are fixed by welding their intersections. The longitudinal pipe 12 and the horizontal pipe 13 shown in the figure are welded and fixed in a state in which the outer peripheral surface of the vertical pipe 12 is aligned with the notch 14 provided in the horizontal pipe 13 and intersected in a predetermined posture. Do. As described above, in the structure in which the vertical pipe 12 and the horizontal pipe 13 overlap to align the notch 14 with the outer peripheral surface, the contact portion between the vertical pipe 12 and the horizontal pipe 13 can be lengthened. The connection strength can be increased.

Furthermore, both ends of the horizontal pipe 13 are welded and fixed to the bent pieces 11B on both sides. The end plate 3 of FIG. 4 is fixed by welding both ends of the horizontal pipe 13 to the inner surface of the both-sides bent piece 11B. The horizontal pipe 13 is welded and fixed to the metal plate 11 in the previous step of fixing the vertical pipe 12 to the horizontal pipe 13 or after the vertical pipe 12 is fixed to the horizontal pipe 13 and then welded and fixed to the metal plate 11 Be done.

(Fixing pin 5)
In the end plate 3 described above, the fixing bar 5 is fixed by inserting the fixing pins 5 at both ends of the horizontal pipe 13. Therefore, at both ends of the horizontal pipe 13, connecting holes 13A for inserting and connecting the fixing pins 5 are provided. Since the horizontal pipe 13 of FIG. 4 uses a cylindrical metal pipe, both ends of the through hole which penetrates the horizontal pipe 13 in the axial direction are used as connection holes 13A. In the battery module of FIG. 4, since the fixing pin 5 is a bolt 5A, female screw holes 13a into which the male screw 5b of the bolt 5A is screwed are provided at both ends of the horizontal pipe 13. The female screw hole 13a is provided so as to extend in the axial direction from the end face. The bolt 5A penetrates the binding bar 4 and is screwed into the female screw hole 13a to fix the binding bar 4 to the end plate 3. However, the fixing pin does not necessarily have to be screwed with a bolt, and can be fixed by pressing the fixing pin into the connection hole of the horizontal pipe, or the fixing pin can be a welding bolt.

(Fixing bolt 6)
Furthermore, the battery module 10 shown in the figure is configured to be fixed to the base plate 9 disposed on the bottom surface of the battery module 10 via the fixing bolt 6 penetrating the vertical pipe 12 of the end plate 3 up and down. The fixing bolt 6 is fixed by screwing the tip end of the screw portion into a nut portion (not shown) provided on the outside of the base plate 9 or screwing it into a female screw hole provided in the base plate 9.

(Bind bar 4)
The side surfaces of the battery stack 2 are respectively covered with a pair of bind bars 4, and the end plates 3 are fastened with the bind bars 4 on the respective side surfaces of the battery stack 2. Each bind bar 4 has a bind bar main surface 41 formed in a size that substantially covers the side surface of the battery stack 2. The bind bar main surface 41 is formed in a flat plate shape to the end edge in the stacking direction of the battery stack 2. It is preferable that the bind bar 4 has a non-bent end which is not bent in an L shape in a cross-sectional view.

The bind bar 4 is extended in the stacking direction of the battery stack 2 as shown in FIGS. 1 and 2 and is fixed to the end plate 3 whose both ends are disposed on both end surfaces of the battery stack 2. The battery stack 2 is fastened in the stacking direction via the end plate 3. The bind bar 4 is a metal plate 11 having a predetermined width and a predetermined thickness along the side surface of the battery stack 2, and is disposed to face both side surfaces of the battery stack 2. The bind bar 4 is provided with a through hole for inserting a bolt 5A, which is a fixing pin 5, to form a stop hole 4a. For the bind bar 4, a metal plate 11 such as iron, preferably a steel plate can be used. The bind bar 4 made of the metal plate 11 is bent by press forming or the like to be formed into a predetermined shape.

The bind bar 4 is provided with an upper surface side bent portion 44 for holding the upper surface of the battery stack 2 along the upper end of the middle portion excluding both end portions of the bind bar main surface 41 and a lower surface side bend for holding the lower surface. The music section 45 is provided. The bind bar main surface 41 has a rectangular shape with a size that covers substantially the entire battery stack 2 and the end plates 3 disposed at both ends thereof. The bind bar main surface 41 shown in FIG. 1 covers almost the entire side surface of the battery stack 2 without any gap. However, the bind bar main surface can also be provided with one or more openings to expose part of the side surface of the battery stack. By forming the opening in the main surface of the bind bar, the battery stack can be exposed and air cooled, or a cooling gas can be supplied. In addition, even if it is not necessary to supply the cooling gas to the main surface of the binding bar from the opening, the opening may be formed on the main surface of the binding bar. This configuration can reduce the weight of the bind bar.

Further, the upper surface side bending portion 44 holds the upper surface of the rectangular battery cell 1 constituting the battery stack 2 and suppresses the positional deviation of the terminal surface of each rectangular battery cell 1 in the vertical direction. Furthermore, the lower surface side bending part 45 hold | maintains the bottom face of the battery laminated body 2 and the end plate 3, and arrange | positions the bottom face of each square battery cell 1 and the end plate 3 on the same plane. The lower surface side bent portion 45 in the figure forms fixing holes for fixing the bottom plate 17 disposed on the bottom side of the battery stack 2 and the end plate 3.

In the bind bar 4, the insulating sheet 16 is disposed on the inner surface of the bind bar main surface 41 and the upper surface side bent portion 44, and the insulating sheet 16 insulates the rectangular battery cells 1 of the battery stack 2 from the bind bar 4. doing. Furthermore, in the battery module 10 shown in FIG. 2, the bottom plate 17 having the insulating property is disposed on the bottom surfaces of the battery stack 2 and the end plate 3, and this bottom plate is fixed via the lower surface side bending portion. It has been arranged.

(Reinforcement part 7)
Furthermore, the bind bar 4 shown in FIG. 2 and FIG. 4 has the reinforcing portion 7 fixed to the inner surface of both end portions in the region facing the end plate 3, and the end plate 3 is It is connected to the bind bar 4. As a result, the end plate 3 can be stably fixed via the reinforcing portions 7 at both ends without thickening the bind bar 4 itself. The reinforcing portion 7 opens a through hole as a connecting recess 7A in order to insert and connect the projecting portion 13B of the horizontal pipe 13 projecting from both side surfaces of the end plate 3. The connecting recess 7A, which is a through hole, is opened so as to have an inner shape into which the projecting portion 13B of the horizontal pipe 13 can be inserted.

The reinforcing portion 7 is made of metal. Preferably, it can be made of the same metal as the bind bar 4 or a metal higher in rigidity than the bind bar 4. The reinforcing portion 7 is preferably integrally formed with the bind bar 4. For example, a tailored blank is used to make the bind bar 4 have a profile thickness. Thereby, the reinforcement part 7 and the bind bar 4 can be shape | molded as one member. Alternatively, the reinforcements 7 individually prepared may be welded to the bind bar 4. Thereby, the reinforcing part 7 can be welded to the bind bar 4 in advance to simplify the assembly process.

The reinforcing portion is not necessarily required, and the bind bar 4 can also directly fix the inner surfaces of both ends of the bind bar main surface 41 to the end plate 3. In this case, the end plates 3 are fixed with the inner surfaces of both end portions of the bind bar main surface 41 in contact with the side surfaces as flat surfaces without projecting both end portions of the horizontal pipe 13 from both side surfaces. Alternatively, the end plate may project both ends of the horizontal pipe from both sides, and at both ends of the bind bar, lock holes for guiding the protrusions may be opened and the lock holes of the horizontal pipe may be formed in the lock holes. Insert and fix the binding bar to the end plate by inserting fixing pins at both ends of the horizontal pipe.

As described above, in the structure in which both end portions of the horizontal pipe projected from both side surfaces of the end plate are locked to the bind bar directly or through the reinforcement portion, the load accompanying the expansion of the rectangular battery cell is the bind bar 4 Can be applied linearly. That is, by configuring to receive a force in the pulling direction of the bind bar, it is possible to increase the rigidity for fastening the battery stack 2.

The battery module 10 described above is placed on the upper surface of the base plate 9, and the fixing bolt 6 penetrating the end plate 3 is screwed into the base plate 9 and fixed at a fixed position of the base plate 9. The base plate 9 is a plate to which the battery module 10 is fixed. In a use example where the battery module 10 is mounted on a vehicle, it can be a frame fixed to the vehicle, for example, a chassis of the vehicle. In the battery module 10 mounted on the vehicle, the fixing bolt 6 is inserted through the insertion hole 12A of the vertical pipe 12 of the end plate 3 and the tip of the fixing bolt 6 is screwed into the female screw hole (not shown) of the chassis. It is fixed to the chassis. The fixing bolt 6 firmly fixes the end plate 3 to the chassis. In this structure, as shown in FIG. 6 and FIG. 7, the battery module 10 can be extremely firmly fixed to the vehicle by fixing the fixing bolt 6 penetrating the end plate 3 directly to the chassis 92 of the vehicle.

(Vehicle equipped with battery module)
The above battery module is most suitable for the power supply which supplies electric power to the motor which runs an electric vehicle. As an electric vehicle mounted with a battery module, a hybrid vehicle or plug-in hybrid vehicle traveling with both an engine and a motor, an electric vehicle traveling only with a motor, etc. can be used, and it is used as a power source of these vehicles. In order to obtain electric power for driving a vehicle, a large-capacity, high-power power supply device may be constructed and mounted by connecting a number of the above-described battery modules in series or in parallel, and further adding necessary control circuits. it can.

FIG. 6 shows an example in which a battery module is mounted on a hybrid vehicle traveling with both an engine and a motor. A vehicle HV equipped with the battery module shown in this figure includes an engine 96 for traveling the vehicle HV and a motor 93 for traveling, a battery module 10 for supplying electric power to the motor 93, and a generator for charging the battery of the battery module 10. A vehicle main body 90 on which the engine 96, the motor 93, the battery module 10, and the generator 94 are mounted, and a wheel 97 driven by the engine 96 or the motor 93 to travel the vehicle main body 90 are provided. The battery module 10 is connected to the motor 93 and the generator 94 via a DC / AC inverter 95. The vehicle HV travels with both the motor 93 and the engine 96 while charging and discharging the rectangular battery of the battery module 10. The motor 93 is driven in a region where the engine efficiency is low, for example, at the time of acceleration or low speed traveling to drive the vehicle. Electric power is supplied from the battery module 10 to drive the motor 93. The generator 94 is driven by the engine 96 or driven by regenerative braking when the vehicle is braked to charge the battery of the battery module 10.

Moreover, FIG. 7 shows the example which mounts a battery module in the electric vehicle which drive | works only by a motor. The vehicle EV mounted with the battery module shown in this figure includes a motor 93 for traveling the vehicle EV, a battery module 10 for supplying electric power to the motor 93, and a generator for charging the rectangular battery of the battery module 10. A vehicle body 90 on which the motor 93, the battery module 10, and the generator 94 are mounted, and a wheel 97 driven by the motor 93 to travel the vehicle body 90 are provided. The battery module 10 is connected to the motor 93 and the generator 94 via a DC / AC inverter 95. Electric power is supplied from the battery module 10 to drive the motor 93. The generator 94 is driven by energy for regenerative braking of the vehicle EV, and charges the rectangular battery of the battery module 10.

The battery module according to the present invention can be suitably used as a power supply device for hybrid cars, plug-in hybrid cars, electric cars and the like.

DESCRIPTION OF SYMBOLS 1 ... square battery cell, 2 ... battery laminated body, 3 ... end plate, 4 ... bind bar, 4a ... locking hole, 5 ... fixing pin, 5A ... bolt, 5a ... bolt head, 5b ... male screw, 6 ... fixing bolt 7 Reinforcement part 7A Connection recess part 9 Base plate 10 Battery module 11 Metal plate 11A plate part 11B Bilateral bent pieces 11b Through holes 12 longitudinal pipes 12A insertion Holes 13 Horizontal pipes 13A Coupling holes 13a Female screw holes 13B Projections 14 Notches 16 insulation sheets 17 bottom plates 18 separators 19 end face spacers 41 bind bars Main surface 44: upper surface side bending portion 45: lower surface side bending portion 90: vehicle body 92: chassis 93: motor 94: generator 95: DC / AC inverter 96: engine 97: 97 Wheels, EV ... vehicle, HV ... vehicle.

Claims

A battery stack formed by stacking a plurality of rectangular battery cells in the thickness direction;
A pair of end plates disposed on both end faces in the stacking direction of the battery stack;
And a bind bar disposed on both sides of the battery stack to fasten the pair of end plates.
The end plate is
A metal plate disposed opposite to the end face of the battery stack;
It comprises a vertically extending longitudinal pipe and a horizontally extending horizontal pipe which are disposed outside the metal plate and fixed in a posture in which they cross each other,
A battery module characterized in that the bind bar is connected to both ends of the horizontal pipe.
A battery module according to claim 1, wherein
The end plate is a plate portion having an outer shape substantially equal to the end face shape of the battery stack, and both bent pieces projecting in the stacking direction of the rectangular battery cells from both side edges in the width direction of the plate portion. A battery module, wherein both ends of the horizontal pipe are fixed to the both-side bent pieces.
The battery module according to claim 1 or 2, further comprising:
A fixing pin for fixing the binding bar on the side surface of the end plate;
The horizontal pipe has connection holes of the fixing pin at both ends,
The battery module, wherein the fixing pin is inserted into the connection hole of the horizontal pipe through the binding bar, and the binding bar is connected to the end plate.
A battery module according to claim 3, wherein
The battery module, wherein the fixing pin is a bolt, the connection hole of the horizontal pipe is a female screw hole, and the bolt is screwed into and fixed to the female screw hole.
The battery module according to the claim, further comprising:
A fixing bolt for fixing the end plate to a base plate disposed on the bottom side of the battery module;
A battery module configured to insert the fixing bolt into the vertical pipe and fix it to a base plate.
The battery module according to any one of claims 1 to 5, wherein
A battery module characterized in that the end plate is formed by connecting a plurality of the vertical pipes and a plurality of the horizontal pipes in a well-gage shape.
The battery module according to any one of claims 1 to 6, wherein
The battery module, wherein the vertical pipe is disposed closer to the battery stack than the horizontal pipe.
The battery module according to any one of claims 1 to 7, wherein
A battery module in which the end plates overlap and fix the longitudinal pipe and the horizontal pipe crossing each other at an intersection.
A battery module according to claim 8, wherein
At the intersection of the vertical pipe and the horizontal pipe, a notch along the outer surface of the vertical pipe is provided on the surface of the horizontal pipe at a position facing the vertical pipe, and the vertical pipe is provided with the vertical pipe A battery module made by aligning the surface of and fixing a vertical pipe to a horizontal pipe.
The battery module according to any one of claims 1 to 9, wherein
The battery module in which the vertical pipe and the horizontal pipe are cylindrical metal pipes.
A battery module according to claim 10, wherein
A battery module in which the vertical pipe and the horizontal pipe are made of iron or iron alloy
A vehicle equipped with the battery module according to any one of claims 1 to 11,
The battery module, a traveling motor powered by the battery module, a vehicle body on which the battery module and the motor are mounted, and a wheel driven by the motor to cause the vehicle body to travel vehicle.