WO2014024432A1

WO2014024432A1 - Vehicle battery system and electric vehicle provided with battery system

Info

Publication number: WO2014024432A1
Application number: PCT/JP2013/004657
Authority: WO
Inventors: 一広藤井; 小村　哲司; 高志瀬戸
Original assignee: 三洋電機株式会社
Priority date: 2012-08-09
Filing date: 2013-08-01
Publication date: 2014-02-13
Also published as: JP2015187911A

Abstract

The present invention joins a binding bar and an end plate at a sufficient linking strength, and holds a battery stack in an ideal compressed state. This battery system is provided with: a battery stack (2) that results from stacking a plurality of rectangular batteries (1); a pair of end plates (3) that compress the battery stack (2); and a binding bar (4) that affixes the end plates at a set spacing. Further provided is an affixing frame (9) at which the battery stack (2) is carried. The end plates (3) are provided with a first through hole (3a) through which an affixing bolt (23) is threaded and that passes vertically. A linking section (4P) provided to both ends of the binding bar (4) is provided with a second through hole (4a) at the position for threading the affixing bolt (23). In the battery system the affixing bolt (23) inserted into the second through hole (4a) of the binding bar (4) and the first through hole (3a) of the end plates (3) is affixed to the affixing frame (9), the binding bar (4) is affixed to the end plates (3), and the binding bar (4) and end plates (3) are affixed to the affixing frame (9).

Description

Battery system for vehicle and electric vehicle equipped with battery system

The present invention relates to a battery system that is mounted on a vehicle and supplies electric power to a vehicle driving motor, and in particular, end plates are arranged at both ends of a battery stack formed by stacking a plurality of rectangular batteries and bound to the end plates. The present invention relates to a vehicle battery system in which a bar is connected to fix a plurality of rectangular batteries in a pressurized state, and an electric vehicle including the battery system.

As a battery system for a vehicle, a battery stack is formed by stacking a large number of square batteries, a pair of end plates are arranged on opposite surfaces of the battery stack, and a bind bar is connected to the end plates to form a square battery. A structure that is fixed in a stacked pressure state has been developed. (See Patent Document 1)

In this battery system, as shown in FIGS. 1 and 2, end plates 203 are arranged at both ends of a battery stack 202 formed by stacking a large number of rectangular batteries 201, and a bind bar 204 is connected to the end plates 203. Thus, the battery stack 202 is fixed in a pressurized state to form a battery block 210. In the battery block 210, both ends of the bind bar 204 are screwed to the end plate 203 with set screws 224, the end plate 203 is fixed at a constant interval, and the battery stack 202 is fixed in a pressurized state. Further, the battery block 210 is fixed to the outer case 209 by screwing a fixing screw 223 that penetrates the bottom plate 209 A of the outer case 209 into the end plate 203 from below.

JP 2010-287514 A

As shown in FIG. 3, the above battery system has a drawback that it is difficult to fix the bind bar 204 and the end plate 203 with sufficient bond strength because the bind bar 204 is fixed only to the end plate 203. In particular, a battery system for a vehicle is required to be light in weight because it is used to improve fuel efficiency. Since the end plate is made of aluminum or plastic, the end plate 203 is firmly fixed to the set screw 224. It is difficult to screw in and fix. Therefore, when the end plate 203 is strongly pressed by the pressure of the battery stack 202 and a force in the opposite direction acts on the set screw 224 that fixes the bind bar 204 to the end plate 203, as shown by the chain line in FIG. As a result, the interval between the end plates 203 becomes wider, and the expanding rectangular battery 201 cannot be held in a pressurized state at a constant interval. This adverse effect can reduce the end plate as a tough material such as iron, but an iron end plate causes an adverse effect that the battery system becomes extremely heavy.

Also, in addition to reducing weight, vehicle battery systems are used in an environment subject to vibrations, so that excellent vibration resistance is also required. Furthermore, in the battery system in which the battery stack is sandwiched between the end plates, the prismatic battery expands with time when charging and discharging are repeated, and it is also necessary to prevent adverse effects due to the expansion of the prismatic battery. In order to prevent excellent vibration resistance and adverse effects due to expansion of the rectangular battery, this type of battery system is fixed to a state in which the battery stack is pressurized with a considerable pressure by the end plate. A battery system that does not have sufficient vibration resistance has a negative effect such that the adjacent rectangular batteries are relatively moved up and down and left and right due to the vibration of the vehicle. In particular, in this type of battery system, a metal plate bus bar is fixed to the electrode terminals of adjacent rectangular batteries and connected in series or in parallel, so when the adjacent rectangular batteries move relatively, the electrode terminals and bus bars are moved. Defects such as damage or deformation occur due to distortion force acting on the fixed part. Further, when the rectangular battery expands over time due to charging / discharging, there are also problems such as an increase in internal resistance and a decrease in electrical characteristics. In order to improve the vibration resistance and prevent the expansion of the rectangular battery, the battery stack is fixed in a stacked state while being pressed with a considerable pressure by an end plate. Since the battery stack is pressed by an end plate connected to the bind bar, how firmly the bind bar can be fixed to the end plate is extremely important for this type of battery system.

An important object of the present invention is to connect the bind bar and the end plate with sufficient bonding strength so that the battery stack can be fixed in an ideal pressure state with a pair of end plates and is ideal for a long period of time. An object of the present invention is to provide a vehicle battery system that can be maintained in a pressurized state and an electric vehicle including the battery system.

Means for Solving the Problems and Effects of the Invention

A battery system for a vehicle according to the present invention includes a battery stack 2 formed by stacking a plurality of rectangular batteries 1 and a pair of end plates 3 that are on opposite surfaces of the battery stack 2 and pressurize the square batteries 1 in the stacking direction. And a bind bar 4 which is connected to the top and bottom of the end plate 3 and fixes the end plate 3 at a constant interval. The battery system further includes a fixed frame 9 on which the battery stack 2 is placed and fixed to the vehicle. In the bind bar 3, connecting portions 4 P provided at both ends are fixed to the end plate 3. The end plate 3 is provided with a first through hole 3a fixed to the fixing frame 9 via a fixing bolt 23 so as to penetrate from the upper surface to the lower surface in the vertical direction. The connecting portion 4P of the bind bar 4 connected to the upper and lower sides of the end plate 3 is in a position that covers the opening of the first through hole 3a provided in the end plate 3, and is inserted into the first through hole 3a. The second through hole 4a is provided at a position where the fixing bolt 23 to be inserted is inserted. In the battery system, the fixing bolt 23 fixed to the fixing frame 9 is inserted into the second through hole 4a provided in the bind bar 4 and the first through hole 3a provided in the end plate 3, and this With the fixing bolt 23, the bind bar 4 is fixed to the end plate 3, and the bind bar 4 and the end plate 3 are fixed to a fixed frame 9 fixed to the vehicle.

The above battery system has the feature that it can be easily and easily assembled and fixed to the vehicle. That is, the above battery system screws the fixing bolt inserted into the through hole between the bind bar and end plate into the fixed frame fixed to the vehicle, fixes the bind bar to the end plate, and both to the fixed frame. This is because it can be fixed. According to this configuration, a feature is also realized in which the interval between the pair of end plates is kept constant over a long period of time, and the deterioration of the electrical characteristics due to the expansion of each rectangular battery over time can be effectively prevented. This is because the battery system described above is fixed to a fixed frame fixed to the vehicle with long fixing bolts that vertically penetrate the end plate.

In the conventional battery system, one end on the screw head side is inserted into the through hole of the bind bar and the tip is screwed into the end plate to be fixed. When the pressure expands and the pressure becomes stronger, as shown by the arrow in FIG. 3, the force acting on the set screw 224 tilts as shown by the chain line, the interval between the end plates 203 increases, and the pressurization state of the rectangular battery 201 changes. There are drawbacks.

On the other hand, in the battery system described above, both ends of the fixing bolt are inserted into the second through hole of the bind bar, and the gap is inserted into the first through hole of the end plate so that the bind bar is used as the end plate. Since it is fixed, a strong force acting in the opposite direction does not act on both ends like a conventional set screw. For this reason, the fixing bolt is not inclined by the pressure of the end plate, and the interval between the end plates does not increase, and the interval between the end plates can be kept constant over a long period of time.

In the above battery system, the fixing bolt is not screwed into the female screw hole of the end plate and fixed by screwing. For this reason, it is not necessary to provide a female screw on the inner surface of the first through hole, and it is not required to have a strength to engage with the female screw and strongly connect it. Therefore, the fixing bolt can be thickened by increasing the inner diameter of the first through hole. Since the force of the binding bar and the end plate acts in a well-balanced manner on the entire thick fixing bolt, there is a feature that the end plate interval can be kept constant with a strong fixing bolt.

In addition, the battery system described above can connect the bind bar and end plate with sufficient bonding strength, and can fix the battery stack to an ideal pressure state with a pair of end plates, and is ideal for a long period of time. A feature that can be maintained in a pressurized state is also realized. This is because the bind bar connected to the end plate is fixed to the end plate via fixing bolts that are fixed to a fixing frame such as a vehicle chassis or an exterior case.

Furthermore, the battery system described above has a feature that it can be fixed to the vehicle extremely firmly while fixing the battery stack in a state of being sandwiched between end plates. It can fix a fixed frame to which the fixing bolts that pass through the bind bar and the end plate are fixed to the vehicle, or use the vehicle chassis as a fixed frame and fix the fixing bolts that pass through the bind bar and the end plate directly to the vehicle chassis. This is because the battery stack can be held in a state of being sandwiched by end plates and fixed to the vehicle.

In the battery system according to the present invention, the end plate 3 is formed as a rectangular plate having a predetermined thickness, and the bind bar 4 can be connected to the four corners of the rectangle.
In the battery system described above, four bind bars are connected to the four corners of the square end plate, so that the end plate can be fixed in an ideal state with the bind bar.

In the battery system of the present invention, the bind bar 4 connects the horizontal portion 4X and the vertical portion 4Y at a right angle so that the cross-sectional shape is L-shaped, and the L-shaped bind bar 4 is connected to the four corners of the rectangular battery 1. The horizontal portion 4X of the bind bar 4 is above and below the rectangular battery 1 to prevent the vertical movement, and the vertical portion 4Y of the bind bar 4 is on both sides of the square battery 1 to move in the horizontal direction. Can be blocked.
The battery system described above has a feature that vibration resistance strength can be further improved because the binding bar can prevent relative movement of the rectangular battery in the vertical and horizontal directions.

In the battery system of the present invention, the bind bar 4 has an end face plate 4T connected to the end edge of the connecting portion 4P. The end face plate 4T is disposed on the outer surface of the end plate 3, and the bind bar 4 is connected to the end plate. 3 can be connected.
The battery system described above has a feature that the end plate can be locked to the end plate and the end plate can be held at a constant interval.

In the battery system of the present invention, the end plate 3 is made of aluminum, and an opening 3X that exposes an intermediate portion of the fixing bolt 23 inserted through the first through hole 3a to the surface of the end plate 3 is provided. The 1st through-hole 3a can be provided above and below.
The battery system described above has a feature that the fixing bolt can be confirmed from the opening because the intermediate portion of the fixing bolt is exposed on the surface of the end plate with the opening provided in the end plate. For example, if the fixing bolt is broken in the middle due to vibration over a long period of time, the breaking of the fixing bolt can be easily confirmed from the opening.

In the battery system of the present invention, the opening 3 X can be a groove 3 Xa that exposes the fixing bolt 23 inserted through the first through hole 3 a on one surface of the end plate 3.
The battery system described above is characterized in that since the opening is opened on one side of the end plate, a reduction in the strength of the end plate can be prevented while exposing a part of the fixing bolt to the surface of the end plate.

In the battery system of the present invention, the opening 3 X can be formed as a slit 3 Xb that exposes the fixing bolt 23 inserted through the first through hole 3 a on both surfaces of the end plate 3.
In the battery system described above, the fixing bolts are exposed on both sides of the end plate. Therefore, the end plate is laminated on the end surface of the battery stack without fixing the front and back, and the battery stack is fixed in a pressurized state to damage the fixing bolt. I can confirm.

In the battery system of the present invention, the rectangular battery 1 can be a non-aqueous electrolyte battery having a battery case 10 as a metal case.
In the above battery system, since the rectangular battery is a non-aqueous electrolyte battery with a metal case, the battery stack can be fixed in a pressurized state with an end plate, and each rectangular battery can be held in a pressurized state at a constant pressure. Moreover, the capacity | capacitance which can be charged / discharged with respect to a volume can be enlarged.

An electric vehicle according to the present invention includes any one of the battery systems 100 described above, a motor 93 for traveling that is supplied with power from the battery system 100, a vehicle main body 90 including the battery system 100 and the motor 93, and a motor. And a wheel 97 that is driven by the vehicle 93 and causes the vehicle main body 90 to travel.
The above-described electric vehicle can effectively prevent the vibration caused by traveling and the negative effects caused by the square battery that is repeatedly charged and discharged and expands with time, while the battery system including the plurality of square batteries is mounted on the vehicle. This is because, by fixing a fixing bolt that penetrates the bind bar and the end plate to the fixing frame, the battery stack can be held in a state of being sandwiched by the end plate and fixed to the fixing frame.

In the electric vehicle of the present invention, the fixed frame 9 can be the vehicle chassis 92.
Since the above-described electric vehicle directly fixes the fixing bolt that penetrates the bind bar and the end plate to the chassis of the vehicle, the electric vehicle can be fixed to the vehicle extremely firmly while improving the working efficiency.

It is the vertical longitudinal cross-sectional view of the conventional battery system. It is a disassembled perspective view of the battery block of the battery system shown in FIG. FIG. 6 is a schematic plan view showing a state in which a force acts outwardly on a connecting portion between a bind bar and an end plate of a conventional battery system. It is a perspective view of the battery system concerning one embodiment of the present invention. FIG. 5 is a partially enlarged vertical longitudinal sectional view of the battery system shown in FIG. 4. FIG. 5 is an exploded perspective view of the battery system shown in FIG. 4. It is a vertical sectional view of the end plate of the battery system shown in FIG. It is a disassembled perspective view which shows the laminated structure of a square battery and a spacer. It is a disassembled perspective view of the battery laminated body formed by laminating | stacking the spacer of another structure and a square battery. It is a vertical sectional view showing another example of the end plate. It is an expansion perspective view of the bind bar of the battery system shown in FIG. It is an expanded view of the bind bar shown in FIG. It is a block diagram which shows the example which mounts a battery system in the hybrid car which drive | works with an engine and a motor. It is a block diagram which shows the example which mounts a battery system in the electric vehicle which drive | works only with a motor.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. However, the embodiment described below exemplifies a battery system for a vehicle and an electric vehicle including the battery system for embodying the technical idea of the present invention. The electric vehicle including the battery system is not specified as follows. Furthermore, this specification does not limit the members shown in the claims to the members of the embodiments.

The battery system shown in FIGS. 4 to 8 includes a battery stack 2 in which a plurality of rectangular batteries 1 are stacked, a pair of end plates 3 disposed at both ends in the stacking direction of the battery stack 2, and both ends. The binding bar 4 is connected to the pair of end plates 3 to fix the plurality of rectangular batteries 1 in a pressurized state in the stacking direction, and the fixed frame on which the battery stack 2 is placed and fixed to the vehicle. 9 and a fixing bolt 23 for fixing the bind bar 4 and the end plate 3 to the fixing frame 9.

As shown in FIGS. 6 and 8, the prismatic battery 1 is a square battery that is wider than the thickness, in other words, is thinner than the width, and is stacked in the thickness direction to form a battery stack 2. The prismatic battery 1 is a non-aqueous electrolyte battery having a battery case 10 as a metal case. The rectangular battery 1 which is a non-aqueous electrolyte battery is a lithium ion secondary battery. However, the square battery may be a secondary battery such as a nickel metal hydride battery or a nickel cadmium battery. The rectangular battery 1 shown in the figure is a battery in which both wide surfaces are quadrangular and are laminated so that both surfaces face each other to form a battery stack 2.

The prismatic battery 1 has an electrode body (not shown) housed in a metal battery case 10 having a rectangular outer shape and is filled with an electrolytic solution. The battery case 10 made of a metal case can be made of aluminum or an aluminum alloy. The battery case 10 includes an outer can 10A in which a metal plate is pressed into a cylindrical shape that closes the bottom, and a sealing plate 10B that airtightly closes an opening of the outer can 10A. The sealing plate 10B is a flat metal plate, and its outer shape is the shape of the opening of the outer can 10A. The sealing plate 10B is laser-welded and fixed to the outer peripheral edge of the outer can 10A to airtightly close the opening of the outer can 10A. The sealing plate 10 B fixed to the outer can 10 A has positive and negative electrode terminals 13 fixed to both ends thereof, and a gas discharge port 12 is provided between the positive and negative electrode terminals 13. A discharge valve 11 that opens at a predetermined internal pressure is provided inside the gas discharge port 12. The battery stack 2 shown in FIG. 6 is formed by stacking a plurality of rectangular batteries 1 in such a manner that the surfaces on which the discharge valves 11 are provided are positioned substantially on the same surface, and the discharge valves 11 of each rectangular battery 1 are arranged on the first surface. 2A. In the illustrated battery stack 2, a plurality of rectangular batteries 1 are stacked in a posture in which the sealing plate 10 B provided with the discharge valve 11 is an upper surface.

The discharge valve 11 is opened when the internal pressure of the rectangular battery 1 becomes higher than the set pressure, thereby preventing the internal pressure from increasing. The discharge valve 11 has a built-in valve body (not shown) that closes the gas discharge port 12. The valve body is a thin film that is destroyed at a set pressure, or a valve that is pressed against the valve seat by an elastic body so as to open at the set pressure. When the discharge valve 11 is opened, the inside of the prismatic battery 1 is opened to the outside through the gas discharge port 12, and the internal gas is released to prevent the internal pressure from increasing.

A plurality of rectangular batteries 1 stacked on each other are connected in series and / or in parallel with each other by connecting positive and negative electrode terminals 13. In the battery system, positive and negative electrode terminals 13 of adjacent rectangular batteries 1 are connected in series and / or in parallel with each other through a bus bar 14. A battery system in which adjacent rectangular batteries are connected in series with each other can increase the output voltage by increasing the output voltage, and can connect adjacent rectangular batteries in parallel to increase the charge / discharge current.

In the battery stack 2 shown in FIG. 5 and FIG. 6, 14 prismatic batteries 1 are stacked with spacers 7 interposed therebetween, and these prismatic batteries 1 are connected in series. In the illustrated battery stack 2, adjacent rectangular batteries 1 are arranged in opposite directions, and adjacent electrode terminals 13 on both sides thereof are connected by a bus bar 14 to connect two adjacent rectangular batteries 1 in series. All the prismatic batteries 1 are connected in series. However, the present invention does not specify the number of prismatic batteries constituting the battery stack and the connection state thereof.

As shown in FIGS. 5 and 8, the battery stack 2 has spacers 7 sandwiched between the stacked rectangular batteries 1. The spacer 7 insulates the adjacent rectangular batteries 1. The spacer 7 shown in the figure is an insulating plate formed of plastic in a plate shape. In particular, a spacer formed of a plastic having a low thermal conductivity has an effect of effectively preventing thermal runaway of adjacent rectangular batteries. The spacer 7 can be stacked so that the adjacent rectangular batteries 1 are not displaced as a shape in which the rectangular batteries 1 are fitted and arranged at a fixed position.

As described above, the rectangular battery 1 that is insulated and stacked by the spacer 7 can have an outer can made of metal such as aluminum. However, it is not always necessary for the battery stack to interpose a spacer between the rectangular batteries. For example, spacers can be formed by insulating rectangular batteries that are adjacent to each other by, for example, forming a rectangular battery outer can with an insulating material, or covering the outer periphery of the rectangular battery outer can with an insulating sheet or insulating paint. It is because it can be made unnecessary. Furthermore, the battery stack without interposing a spacer between the square batteries is a method of directly cooling using a refrigerant or the like without adopting an air-cooling method in which cooling air is forced between the square batteries to cool the square batteries. Can be used to cool the prismatic battery.

Further, the spacer 7 shown in FIGS. 5 and 8 is provided with a cooling gap 16 for allowing a cooling gas such as air to pass through a portion sandwiched between the prismatic battery 1 in order to effectively cool the prismatic battery 1. Is provided. The spacer 7 of FIGS. 5 and 8 is provided with grooves 15 extending to both side edges on the surface facing the prismatic battery 1, and a cooling gap 16 is provided between the spacer 7 and the prismatic battery 1. In the illustrated spacer 7, a plurality of grooves 15 are provided in parallel with each other at a predetermined interval. In the illustrated spacer 7, grooves 15 are provided on both surfaces, and a cooling gap 16 is provided between the prismatic battery 1 and the spacer 7 adjacent to each other. This structure has an advantage that the square battery 1 on both sides can be effectively cooled by the cooling gaps 16 formed on both sides of the spacer 7. However, the spacer can be provided with a groove only on one side, and a cooling gap can be provided between the prismatic battery and the spacer. The cooling gap 16 in the figure is provided in the horizontal direction so as to open to the left and right of the battery stack 2. The air forcibly blown into the cooling gap 16 directly and efficiently cools the outer can 10 A of the rectangular battery 1. This structure has a feature that the prismatic battery 1 can be efficiently cooled while effectively preventing thermal runaway of the prismatic battery 1.

The spacer 7 described above can cool the prismatic battery 1 by providing a cooling gap 16 between the spacer 7 and forcibly blowing a cooling gas such as cooling air into the cooling gap 16. However, it is not always necessary to provide a cooling gap between the spacer and the rectangular battery. As shown in FIG. 9, the spacer 37 is exposed to the surface of the battery stack 32, and the exposed portion 37 A is used as the cooling plate 20. It can also be set as the structure connected to a thermal coupling state. In this battery system, the cooling plate 20 can be cooled, the spacer 37 can be cooled by the cooling plate 20, and the prismatic battery 1 can be cooled by the spacer 37. The cooling plate 20 can be cooled by providing heat radiation fins (not shown) on the surface, or can be forcibly cooled by circulating a cooling refrigerant or coolant inside. Furthermore, although not shown, the surface of the prismatic battery can be insulated without providing a spacer between the prismatic batteries.

The end plate 3 is connected to the bind bar 4 and fixed at a fixed interval. The end plate 3 is manufactured by processing aluminum into a plate having a predetermined thickness. However, the end plate may have a structure in which plastic is molded into a plate shape and a metal plate is laminated on the outer surface. The outer shape of the end plate 3 is substantially equal to or slightly larger than the outer shape of the prismatic battery 1, and a rectangular shape that is not deformed by connecting the bind bars 4 to the four corners and fixing the battery stack 2 in a pressurized state. It is a plate shape. The end plate 3 shown in FIGS. 4, 6, and 7 has a binding bar 4 connected to the four corners thereof so as to be in close contact with the surface of the prismatic battery 1 and pressurize the prismatic battery 1 with a uniform pressure. Fix to state. The end plate 3 pressurizes the battery stack 2 from both end surfaces to hold the prismatic battery 1 in a pressurized state.

The end plate 3 is fixed to a fixed frame 9 fixed to the vehicle via fixing bolts 23. The fixing bolt 23 is also used as a bolt for fixing the bind bar 4 to the end plate 3. In order to insert the fixing bolt 23, the end plate 3 is provided through the first through hole 3a in the vertical direction from the upper surface to the lower surface. In the battery system of FIG. 4, the bind bar 4 is connected to the four corners of the end plate 3, so the first through holes 3 a are provided on both sides of the end plate 3. The bind bar 4 is connected to both the upper surface and the lower surface of the first through hole 3 a provided on both sides of the end plate 3, and is fixed to the four corners of the end plate 3 through fixing bolts 23.

As shown in FIGS. 4 to 7, the end plate 3 is provided with an opening 3X that exposes an intermediate portion of the fixing bolt 23 inserted into the first through hole 3a to the surface of the end plate 3, and the end plate 3 First through holes 3a are provided on the upper and lower sides. The fixing bolt 23 is disposed in a non-contact state on the inner surface of the opening 3X. That is, a gap is provided between the inner surface of the opening 3 X and the fixing bolt 23. This is because the fixing bolt 23 exposed to the opening 3X can be observed from the outside. The opening 3X has an inner width wider than the inner diameter of the first through hole 3a. The opening 3X is a groove 3Xa that exposes the fixing bolt 23 on one side of the end plate 3A as shown in a partially enlarged view of FIG. 5, or the fixing bolt 23 of the end plate 3B as shown in FIG. The slit 3Xb is exposed on both sides. The end plate 3A that exposes the fixing bolt 23 to one side of the end plate 3 opens the opening 3X to the outside of the end plate 3 so that the exposed portion of the fixing bolt 23 can be observed from the outside of the battery system.

In the battery system, end plates 3 are arranged at both ends of the battery stack 2, and the end plates 3 at both ends are pressed by a press (not shown), and the prismatic battery 1 is held in a state of pressing in the stacking direction. In this state, the bind bar 4 is fixed to the end plate 3, and the battery stack 2 is held and fixed at a predetermined tightening pressure. After the end plate 3 is connected to the bind bar 4, the pressurization state of the press machine is released.

The binding bar 4 is fixed to the end plate 3 with connecting portions 4P provided at both ends. The bind bar 4 is a metal plate having an L-shaped cross section formed by connecting a horizontal portion 4X and a vertical portion 4Y at a right angle. The metal plate of the bind bar 4 is iron or an iron alloy. The bind bar 4 in FIGS. 6 and 11 connects the end face plate 4T to the end edge of the connecting portion 4P. The end face plate 4T is connected to the edges of the vertical portion 4Y and the horizontal portion 4X. The end surface plate 4T is connected to the vertical portion 4Y and the horizontal portion 4X at a right angle so as to contact the outer surface of the end plate 3 in a surface contact state. The bind bar 4 having this shape can be manufactured by pressing a metal plate. However, the bind bar 4 shown in FIGS. 11 and 12 is provided with a protruding portion 4Z outside the horizontal portion 4X. An end face plate 4T is formed. The protrusion 4Z shown in the drawing is composed of an end face plate 4T connected to the outer edge of the horizontal part 4X, and a laminated part 4R connected to one side of the end face plate 4T on the vertical part 4Y side. The bind bar 4 is formed by bending the end surface plate 4T of the projecting portion 4Z at a right angle with respect to the horizontal portion 4X, and further bending the stacked portion 4R at a right angle with respect to the end surface plate 4T. 4R is fixed by welding to the vertical portion 4Y. Thus, the bind bar 4 forms an end face plate 4T in a vertical posture on the end edge. The laminated portion 4R to be welded is welded along the boundary with the vertical portion 4Y, or overlapped with the vertical portion 4Y and connected by a method such as spot welding. The bind bar 4 shown in the figure is provided with a protruding portion 4Z on the horizontal portion 4X, bending the protruding portion 4Z, and fixing the laminated portion 4R to the vertical portion 4Y to form an end plate 4T in a vertical posture. The bind bar may be provided with a protruding portion in the vertical portion, and the protruding portion is bent to provide an end face plate, and the laminated portion is welded and fixed to the horizontal portion. Furthermore, the bind bar is provided with protrusions on both the horizontal part and the vertical part, and the protrusions are bent, and the bent protrusions are stacked and welded to provide an end face plate. You can also.

The bind bar 4 is connected to the end plate 3 in a state where the end plate 4T is disposed on the outer surface of the end plate 3 and is locked to the end plate 3. The bind bar 4 is fixed to the side surface of the end plate 3 with a set screw 24 penetrating the vertical portion 4Y in a state where the end face plate 4T is locked to the end plate 3. In the illustrated bind bar 4, insertion holes 4 b through which the set screws 24 are inserted are opened at both ends of the vertical portion 4 Y, and the end plate 3 A is provided with female screw holes 3 b at positions where the set screws 24 are screwed.

The bind bar 4 is connected to the end plate 3 with a set screw 24, and is further firmly fixed to the end plate 3 via a fixing bolt 23 that is screwed into a fixing frame 9 fixed to the vehicle. In order to insert the fixing bolt 23, the bind bar 4 is provided with a second through hole 4a through which the fixing bolt 23 is inserted, through the horizontal portion 4X, in the connecting portion 4P at both ends. The connecting portion 4P of the bind bar 4 has a fixing bolt 23 inserted into the first through hole 3a, with the horizontal portion 4X covering the opening edge of the first through hole 3a provided in the end plate 3. A second through hole 4a is provided at the insertion position. That is, in a state where the bind bar 4 is fixed to the end plate 3, the second through hole 4 a of the bind bar 4 and the first through hole 3 a of the end plate 3 are arranged in a straight line, and the fixing bolt is here. 23 is inserted.

As shown in FIG. 7, the fixing bolt 23 passes through the first through hole 3 a of the end plate 3 from the second through hole 4 a of the upper bind bar 4, and further, 2 passes through the through-hole 4a and is fixed to the fixed frame 9 by screwing. The fixing frame 9 is provided with a female screw hole 19 at a position where the fixing bolt 23 is screwed and fixed. The female screw hole 19 is provided directly in the fixed frame 9, or is provided by fixing a nut to the lower surface of the fixed frame by a method such as welding.

In the battery system 100 described above, both ends of the bind bar 4 are fixed to the pair of end plates 3, the battery stack 2 is sandwiched between the pair of end plates 3, and each rectangular battery 1 is stacked in a stacking direction with a predetermined tightening pressure. Press to fix. The pressure at which the end plate 3 pressurizes the rectangular battery 1 is preferably set to 10 MPa or more and 1 MPa or less. If the tightening pressure is too weak, the expansion of the prismatic battery 1 cannot be effectively suppressed. On the other hand, if it is too strong, the battery case 10 of the prismatic battery 1 is damaged. In particular, in the prismatic battery 1 using the battery case 10 as a metal case, the deformation amount of the battery case 10 in the stacking direction of the prismatic battery 1 is extremely small and substantially does not change. The square battery 1 cannot be reliably held in a pressurized state, and if the tightening pressure is too strong, the battery case 10 of the square battery 1 is damaged. For this reason, it is extremely important to press and fix the respective square batteries 1 in the stacking direction while keeping the tightening pressure within a predetermined range. Accordingly, the tightening pressure is set to an optimum value in consideration of the type and size of the rectangular battery 1 and the material, shape, thickness, size, and physical properties of the electrode body of the battery case 10.

The battery system in which the bind bar 4 is fixed to the end plate 3 with the set screw 24 fixes the battery stack 2 in the compressed state with the end plate 3. In this battery system, when the rectangular battery 1 is repeatedly charged and discharged and gradually expands, the pressure at which the battery stack 2 pressurizes the end plate 3 is further increased. If the interval between the end plates 3 is widened in this state, the expansion of the prismatic battery 1 cannot be surely prevented, and adverse effects such as a decrease in electrical characteristics of the prismatic battery 1 and a shortened life occur. 4 to 7, the fixing bolt 23 inserted through the second through hole 4a of the bind bar 4 and the first through hole 3a of the end plate 3 is screwed into the fixing frame 9 fixed to the vehicle. With a unique structure that is fixed to the vehicle, the distance between the end plates 3 is kept constant.

The battery stack 2 is placed on the upper surface of the fixing frame 9, and a fixing bolt 23 passing through the bind bar 4 and the end plate 3 is screwed to fix the battery stack 2 in place. The fixed frame 9 is a frame fixed to the vehicle, and can be a chassis 92 of the vehicle, for example. The battery system using the fixed frame 9 as the vehicle chassis 92 is mounted on the vehicle in a state where the bind bar 4 is fixed to the end plate 3, and the fixing bolt 23 is connected to the second through hole 4 a of the bind bar 4 and the end plate 3. The front end of the fixing bolt 23 is inserted into the first through hole 3 a and screwed into the female screw hole 19 of the chassis 92 to be fixed to the chassis 92 of the vehicle. The fixing bolt 23 fixes the bind bar 4 to the end plate 3 more firmly, and firmly fixes the bind bar 4 and the end plate 3 to the chassis 92. As shown in FIGS. 5 and 13, this structure directly fixes the fixing bolt 23 that penetrates the bind bar 4 and the end plate 3 to the vehicle chassis 92, so that the battery system 100 is very firmly attached to the vehicle. Can be fixed.

In the above embodiment, the battery stack 2 is fixed to the vehicle chassis 92 as the fixed frame 9, but is not necessarily fixed to the vehicle chassis 92. The battery system includes a fixed frame on which the battery stack is placed, and a fixing bolt that fixes the fixing frame and the end plate. The fixing bolt fixes the end plate and the bind bar together to the fixing frame. do it. For example, in a configuration including an exterior case and an exterior frame in which the battery system is stored, both the bind bar and the end plate are fixed to the exterior case and the exterior frame via fixing bolts, and the exterior case and the exterior frame are attached to the vehicle. Can be fixed. Therefore, the fixed frame can be an outer case that is a housing for storing the battery stack or a frame of the outer case, or a base plate or frame that can be fixed by placing the battery stack on the upper surface.

In the battery system, for example, a metal base plate is manufactured as a fixed frame, a battery stack is placed on the base plate, and the second through hole of the bind bar and the first through hole of the end plate are mounted. The battery stack can also be fixed to the fixed frame by screwing the inserted fixing bolt into the female screw hole of the base plate. As shown in FIG. 14, the battery system 100 is fixed to a vehicle by fixing a base plate 9A, which is a fixed frame 9, to a vehicle chassis 92.

The above battery system is mounted on an electric vehicle and supplies electric power to a motor that runs the electric vehicle. As an electric vehicle equipped with a battery system, an electric vehicle such as a hybrid vehicle or a plug-in hybrid vehicle that runs with both an engine and a motor, or an electric vehicle that runs only with a motor can be used, and used as a power source for these electric vehicles. Is done.

(Battery system for hybrid vehicles)
FIG. 13 shows an example in which a battery system is mounted on a hybrid vehicle that runs with both an engine and a motor. A vehicle HV equipped with the battery system shown in this figure has an engine 96 and a running motor 93 that run the vehicle HV, a battery system 100 that supplies power to the motor 93, and power generation that charges a square battery of the battery system 100. A vehicle body 90 on which the machine 94, the engine 96, the motor 93, the battery system 100, and the generator 94 are mounted, and wheels 97 that are driven by the engine 96 or the motor 93 to drive the vehicle body 90. . The battery system 100 is connected to a motor 93 and a generator 94 via a DC / AC inverter 95. The vehicle HV travels by both the motor 93 and the engine 96 while charging and discharging the square battery of the battery system 100. The motor 93 is driven to drive the vehicle when the engine efficiency is low, for example, during acceleration or low-speed driving. The motor 93 is driven by power supplied from the battery system 100. The generator 94 is driven by the engine 96 or is driven by regenerative braking when the vehicle is braked, and charges the prismatic battery of the battery system 100.

(Battery system for electric vehicles)
FIG. 14 shows an example in which a battery system is mounted on an electric vehicle that runs only with a motor. A vehicle EV equipped with the battery system shown in this figure includes a traveling motor 93 that travels the vehicle EV, a battery system 100 that supplies electric power to the motor 93, and a generator that charges a rectangular battery of the battery system 100. 94, a vehicle main body 90 on which the motor 93, the battery system 100, and the generator 94 are mounted, and a wheel 97 that is driven by the motor 93 and causes the vehicle main body 90 to travel. The battery system 100 is connected to a motor 93 and a generator 94 via a DC / AC inverter 95. The motor 93 is driven by power supplied from the battery system 100. The generator 94 is driven by energy when regeneratively braking the vehicle EV, and charges the square battery of the battery system 100.

The battery system of the present invention is optimally used for a power supply device that supplies electric power to a motor of a vehicle that requires high power.

DESCRIPTION OF SYMBOLS 100 ... Battery system 1 ... Square battery 2 ... Battery laminated body 2A ... 1st surface 3 ... End plate 3A ... End plate 3B ... End plate 3a ... 1st through-hole 3b ... Female screw hole 3X ... Opening part 3Xa ... Groove 3Xb ... Slit 4 ... Bind bar 4X ... Horizontal part 4Y ... Vertical part 4Z ... Projection part 4P ... Connecting part 4T ... End face plate 4R ... Laminated part 4a ... Second through hole 4b ... Insertion hole 7 ... Spacer 9 ... Fixed frame 9A ... Base plate 10 ... Battery case 10A ... Exterior can 10B ... Sealing plate 11 ... Discharge valve 12 ... Gas discharge port 13 ... Electrode terminal 14 ... Bus bar 15 ... Cooling groove 16 ... Rejection clearance 19 ... Female screw hole 20 ... Cooling plate 23 ... Fixing screw 24 ... Set screw 32 ... Battery stack 37 ... Spacer 37A ... Exposed part 90 ... Vehicle body 92 ... Chassis 93 ... Motor 94 ... Generator 95 ... DC / AC inverter 96 ... Engine 97 ... Wheel 201 ... Square battery 202 ... Battery stack 203 ... End plate 204 ... Bind bar 209 ... Exterior case 209A ... Bottom plate 210 ... Battery block 223 ... Fixing screw 224 ... Set screw EV ... Vehicle HV ... Vehicle

Claims

A battery laminate formed by laminating a plurality of prismatic batteries;
A pair of end plates that are on opposite surfaces of the battery stack and pressurize the square batteries in the stacking direction;
A battery system comprising a bind bar connected to the top and bottom of the end plate and fixing the end plate at a constant interval,
Furthermore, the battery stack is mounted and includes a fixed frame fixed to the vehicle,
The connecting portions provided at both ends of the bind bar are fixed to the end plate,
The end plate is provided with a first through hole that is fixed to the fixing frame via a fixing bolt, penetrating in a vertical direction from the upper surface to the lower surface,
The connecting portion of the bind bar connected to the top and bottom of the end plate is in a position that covers the opening of the first through hole formed in the end plate, and is fixed to be inserted into the first through hole. A second through hole is provided at a position where the bolt is inserted,
A fixing bolt fixed to the fixing frame is inserted into a second through hole provided in the bind bar and a first through hole provided in the end plate, and the bind bolt is used to fix the bind. A battery system for a vehicle, wherein a bar is fixed to the end plate, and the bind bar and the end plate are fixed to the fixed frame fixed to the vehicle.
The vehicle battery system according to claim 1, wherein the end plate is a quadrangular plate having a predetermined thickness, and a bind bar is connected to four corners of the quadrangle.
The binding bar has a horizontal section and a vertical section connected at a right angle, and the cross-sectional shape is L-shaped, and the L-shaped binding bars are arranged at the four corners of the prismatic battery,
The horizontal part of the bind bar is above and below the rectangular battery and prevents vertical movement, and the vertical part of the bind bar is on both sides of the square battery and prevents horizontal movement. The battery system for vehicles described in 1.
The bind bar includes an end plate connected to an end edge of a connecting portion, the end plate is disposed on an outer surface of the end plate, and the bind bar is connected to the end plate. Battery system for vehicles.
The end plate is made of aluminum, an opening for exposing an intermediate portion of the fixing bolt inserted through the first through hole to the surface of the end plate is provided, and first through holes are provided above and below the opening. The battery system for vehicles according to any one of claims 1 to 4.
The vehicle battery system according to claim 5, wherein the opening is a groove that exposes a fixing bolt inserted into the first through hole on one side of the end plate.
6. The vehicle battery system according to claim 5, wherein the opening is a slit that exposes fixing bolts inserted into the first through hole on both sides of the end plate.
The vehicle battery system according to any one of claims 1 to 7, wherein the rectangular battery is a non-aqueous electrolyte battery using a battery case as a metal case.
An electric vehicle comprising the battery system according to any one of claims 1 to 8,
The battery system, a travel motor powered by the battery system, a vehicle body on which the battery system and the motor are mounted, and wheels that are driven by the motor and cause the vehicle body to travel. An electric vehicle provided with the battery system characterized by the above.
An electric vehicle comprising the battery system according to claim 9,
The electric vehicle including a battery system, wherein the fixed frame is a vehicle chassis.