JP2001345086A - Battery pack - Google Patents

Abstract

PROBLEM TO BE SOLVED: To simply and easily connect batteries with a small number of parts, and in the state of low resistance, and surely connect batteries while reducing a manufacturing cost. SOLUTION: A battery pack is obtained by linearly coupling plural batteries 2 via connection fittings 1. The connection fittings 1 is a cap 9 which presses an elastic body 11 of a safety valve 10 that is installed at a sealing plate 5 of the battery 2, and a welding part 1B which is welded to the battery 2 is installed at this cap 9. The welding part 1B of the connection fittings 1 is welded to the battery 2, and neighboring batteries 2 are linearly connected.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an assembled battery in which a plurality of batteries are connected in a straight line. In particular, the present invention
The present invention relates to a battery pack most suitable for being mainly used as a power source for a motor for driving an automobile.

[0002]

2. Description of the Related Art An assembled battery in which a plurality of batteries are connected in a straight line is arranged with a connection fitting sandwiched between the secondary batteries, and connected to the positive and negative electrodes of the secondary battery via the connection fitting. The secondary batteries are linearly connected in series by spot welding. A power supply module having this structure is described in JP-A-10-106533. The module battery having this structure is particularly suitable for an application requiring a large current, such as for an automobile.

In a conventional module battery, a cylindrical battery 22 is connected in series as shown in a sectional view of FIG. 3 using a dish-shaped connection fitting 21 having a shape shown in FIGS. The connection fitting 21 welds the plate portion 21A to the positive electrode located on the end face of the cylindrical battery 22 and connects the side wall portion 21B to the cylindrical battery 2.
2 and connected by welding to the negative electrode located on the side surface of the outer can 24.

[0004] The plate portion 21 A of the connection fitting 21 is provided with a projection 23 to be welded to the positive electrode of the cylindrical battery 22. The upper surface of the projection 23 is pressed with a welding electrode rod to weld the projection 23 to the positive electrode.

[0005] Further, in the connection fitting 21, the cylindrical battery 22 is inserted into the inside of the side wall 21B, and the side wall 21B is spot-welded to the outer can 24 which is the negative electrode of the cylindrical battery 22. The side wall 21B is also similar to the plate 21A,
The outside of the projection 23 is pressed with a welding electrode rod, and the projection 23 provided on the inner surface is welded to the outer can 24.

FIG. 4 shows a module battery in which a plurality of cylindrical batteries 22 are connected by connecting fittings 21. As shown in this figure, the module battery has a plurality of cylindrical batteries 22 connected linearly in series.

[0007]

The assembled battery of this structure has the following features.
Since the two batteries are connected via the connection fitting, it is necessary to weld the dish-shaped connection fitting to both the sealing plate and the outer can. For this reason, there is a disadvantage in that it takes time to weld the connection fitting. Furthermore, since a specially designed connection fitting is used for connecting the battery, there is a disadvantage that the cost of parts is increased. In addition, since the battery is connected via the connection fitting, there is a disadvantage that the resistance of the connection portion is increased by the connection fitting.

[0008] Batteries in which batteries are connected in a straight line via connection fittings are often used for applications requiring extremely high output, such as power supplies for automobiles. A battery pack for this application connects a considerably large number of batteries, for example, 100 or more, in series, thereby simplifying the connection of the batteries, further reducing the number of components for connection, and It is extremely important to reduce the resistance of the device.

The present invention has been developed with the object of realizing this. An important object of the present invention is to enable a simple and easy connection of a battery with a small number of parts and in a low-resistance state. It is to provide an assembled battery. Another important object of the present invention is to provide a battery pack which can reduce the manufacturing cost and reliably connect the batteries.

[0010]

According to the battery pack of the present invention, a plurality of batteries 2 are linearly connected via a connection fitting 1.
The connection fitting 1 is a safety valve 1 provided on a sealing plate 5 of the battery 2.
The cap 9 presses the elastic body 11, and the cap 9 is provided with a welding portion 1 </ b> B for welding to the battery 2. The welded portion 1B of the connection fitting 1 is welded to the battery 2 to connect the adjacent batteries 2 linearly.

The connection fitting 1 preferably includes a pressing portion 1a for pressing the elastic body 11 of the safety valve 10, a fixing portion 1b outside the pressing portion 1a, and a welding portion 1B outside the fixing portion 1b. And the fixing portion 1b is attached to the sealing plate 5 of the battery 2.
It is fixed to. In the connection fitting 1 having this structure, more preferably, the welding portion 1B is formed in a flange shape protruding toward the bottom surface of the battery 2 to be welded, and the flange-like welding portion 1B is formed.
Is welded to the bottom surface of the battery 2. Furthermore, in this connection fitting 1, the flange-shaped welded portion 1B is made to protrude from the pressing portion 1a, and the height of the welded portion 1B protruding from the pressing portion 1a is set to 5 mm or less. However, in the connection fitting 1, the flange-shaped welding portion 1B and the pressing portion 1a can be located on the same plane.

The welded portion 1B of the connection fitting 1 has a cylindrical shape into which an end of the battery 2 to be welded can be inserted.
Can be welded to the side surface of the outer can 4.

Further, the connection fitting 1 is provided with the projection 13 at the welding portion 1B, and the projection 13 is welded to the battery 2 so as to be more reliably welded to the battery 2.

[0014]

Embodiments of the present invention will be described below with reference to the drawings. However, the embodiments described below exemplify assembled batteries for embodying the technical idea of the present invention, and the present invention does not specify the assembled batteries as follows.

Further, in this specification, in order to make it easy to understand the claims, the numbers corresponding to the members shown in the embodiments will be referred to as “claims” and “ In the column of “means”.
However, the members described in the claims are not limited to the members of the embodiments.

In the battery packs shown in FIGS. 5 to 8, the batteries 2 are connected in series in a straight line with a connection fitting 1. Further, in the battery pack shown in this figure, an insulator 3 is provided between the connection fitting 1 and the battery 2. In the battery pack shown in the figure, the battery 2 is a cylindrical secondary battery.

The battery 2 is a single type nickel-hydrogen battery. However, the battery pack of the present invention does not specify the battery 2 as a single type nickel-metal hydride battery. A battery such as a nickel-cadmium battery or a lithium ion secondary battery can be used as the battery. Also, the size of the battery is not limited to a single type, and various secondary batteries such as a square type can be used.

The connection fitting 1 also uses a cap 9 welded to the sealing plate 5 of the battery 2. Therefore, the connection fitting 1 has a shape in which the cap 9 fixed to the sealing plate 5 is further extended toward the outer edge, and the welded portion 1B is provided on the outer peripheral portion. 6 includes a plate portion 1A and a welded portion 1B. The plate portion 1A has a pressing portion 1a for pressing the elastic body 11 of the safety valve 10 and an outer portion of the pressing portion 1a. A certain fixing portion 1b. The outer shape of the plate portion 1A is substantially equal to the shape of the end face of the battery 2. In a connection fitting 1 for connecting a cylindrical battery, the plate portion 1A has a disk shape. Although not shown, the connection fitting for connecting the prismatic battery includes a plate portion,
The prismatic shape is almost the same as the outer shape of the battery end face.

The pressing portion 1a provided in the center of the plate portion 1A is provided inside the ring-shaped fixing portion 1b, protrudes from the fixing portion 1b, and has an elastic body 1 inside.
1 is stored. The pressing portion 1a can hold and store the elastic body 11 so as not to be displaced. Also, since it projects outward, it accommodates the thick elastic body 11 and
The stroke of the zero valve element 12 can be increased. Battery 2 shown
The elastic body 11 is a coil spring which is a pressing spring. As the elastic body, a rubber-like elastic body can be used instead of the coil spring.

The fixing portion 1b is fixed to the upper surface of the sealing plate 5 by welding. The fixing portion 1b has a flat shape in surface contact with the upper surface of the sealing plate 5, and is fixed to the sealing plate 5 by spot welding.
The sealing plate 5 is provided with a recess 5A at a position facing the pressing portion 1a, and is provided at the bottom of the recess 5A so as to penetrate the valve hole 5B.
The valve hole 5B is closed by the valve body 12 in a normal use state. The valve element 12 is pressed against the surface side of the valve hole 5B by the elastic body 11, and closes the valve hole 5B. Only when the internal pressure of the battery 2 rises and becomes higher than the set pressure, the valve body 1
2 is lifted, the safety valve 10 is opened, and the gas or the like in the battery 2 passes through the valve hole 5B. The gas or the like that has passed through the valve hole 5B passes through a through hole (not shown) provided in the pressing portion 1a and is discharged to the outside of the battery 2.

In the connection fitting 1 shown in FIG. 6, a holding portion 1c for holding the bottom surface of the battery 2 is provided outside the fixing portion 1b.
Is connected to a cylindrical welded portion 1B. Holder 1c
Project from the pressing portion 1a. The height at which the holding portion 1c projects from the pressing portion 1a is lower than 5 mm. If the holding portion 1c protrudes higher than this, not only does the overall length of the battery pack increase, but also the bending strength of the connecting portion connecting the battery 2 to the connecting fitting 1 decreases. Connection fitting 1 shown
Has the holding portion 1c protruding from the pressing portion 1a,
The holding portion and the pressing portion may be on the same plane. However, the connection fitting has a through hole for discharging gas to the outside in the vertical wall of the pressing portion.

Since the connection fitting 1 of FIG. 7 connects the cylindrical battery 2, the plate portion 1A is formed in a disk shape and the welding portion 1 is formed.
B has a cylindrical shape. The welded portion 1B is spot-welded or laser-welded to the outer peripheral surface of the battery 2. The welding portion 1 </ b> B is preferably provided with a projection (not shown) and welded to the outer can 4 of the battery 2.
Further, the connection fitting 1 shown in the figure is divided into a plurality of parts by providing a cutout portion 8 at a welded portion 1B formed in a cylindrical shape. The welded portion 1B is easily deformed and surely comes into contact with the surface of the outer can 4. In the connection fitting 1 of FIG. 7, the cutouts 8 are provided at equal intervals at a 90-degree pitch. Further, the connection fitting 1 shown in FIG.
The cutting portion 8 is provided to extend from the welding portion 1B to the periphery of the plate portion 1A.

In the connection fitting 1 having this structure, the welding portion 1B can be elastically deformed by deforming both the welding portion 1B and the plate portion 1A, so that the welding portion 1B can more reliably come into contact with the surface of the outer can 4. However, it is not always necessary to provide the cut portion extending to the plate portion, and it is also possible to use a connection fitting without the cut portion. Further, the connection fitting 1 shown in FIG.
Has four cutouts 8, but the cutouts may be three or less, or five or more.

The welded portion 1B having the above structure is connected to the battery 2 by spot welding or connected to the battery 2 by laser welding. In the spot welding, the welding electrode rod is pressed against the welded portion 1B of the connection fitting 1, and the welded portion 1B is
Weld to. The welded portion 1B pressed by the welding electrode rod is
The battery 2 is brought into contact with the surface of the battery 2, and a large current flows in this state, and the battery 2 is welded. In the laser welding, the welding portion 1 </ b> B is pressed with a pressing tool to make contact with the battery 2. In this state,
The welding portion 1B is irradiated with a laser beam, and the welding portion 1B is melted and welded to the battery 2 with the laser beam.

In the battery packs shown in FIGS. 9 to 11, the batteries 2 are connected by connecting fittings 1 having different shapes. This connection fitting 1
The welding portion 1B is formed in a flange shape protruding toward the bottom surface of the battery 2 to be welded, and the flange-like welding portion 1B is welded to the bottom surface of the battery 2. The flange-shaped welded portion 1 </ b> B has a plane shape parallel to the battery bottom surface so as to make surface contact with the bottom surface of the battery 2. Further, the flange-shaped welded portion 1B protrudes from the pressing portion 1a, and its protruding height is 5 mm or less. However, although not shown, the flange-shaped welded portion may be flush with the pressing portion. The welding portion 1B shown in FIG. 10 has a projection 13 at a portion to be welded to the battery 2.

In the connection fitting 1 shown in FIG. 10, a large current pulse is applied in a direction in which the battery 2 to be connected is discharged in a state where the welding part 1B of the connection fitting 1 is pressed against the bottom surface of the battery 2, so that the welding part 1B is It is welded to the bottom of the outer can 4. In the welded portion 1B with the projection 13, a large current flows intensively in this portion, and the welded portion 1B is securely welded to the bottom surface of the outer can 4 of the battery 2. In the battery pack having this structure, the outer shape of the connection fitting 1 is reduced, in other words, the path through which the current flows through the connection fitting 1 can be shortened, so that the battery 2 can be connected with a lower resistance.

The connection fitting 1 having the above structure is manufactured by pressing a metal plate. As the metal plate, a steel plate plated with nickel is used. It is manufactured by cutting and pressing a plated metal plate, or by cutting and pressing a non-plated metal plate and then plating. The metal plate for manufacturing the connection fitting 1 has, for example, a thickness of 0.8
mm. However, this metal plate has a thickness of 0.2 to
It may be 1.2 mm, preferably 0.3 to 1 mm, and more preferably 0.4 to 0.9 mm. The thickness of the connection fitting 1 is preferably smaller than that of the sealing plate 5. This is for reliably welding the connection fitting 1 to the metal plate of the sealing plate 5.

The insulator 3 is entirely formed of an insulating material such as plastic. The insulator 3 shown in FIG. 6 and FIG.
The cylindrical cap 3A and the insulating plate 3B for inserting the end portions are integrally formed of plastic.
The insulator 3 integrally formed as a whole is formed of a hard or soft plastic or is formed of a rubber-like elastic body. As the hard plastic, polyethylene resin, polypropylene resin, nylon resin, vinyl chloride resin and the like can be used. As the soft plastic, soft vinyl chloride resin, EVA, urethane resin, silicone resin, and the like can be used. Natural or synthetic rubber can be used for the rubber-like elastic body.

The insulator 3 may be formed of a soft plastic or a rubber-like elastic body without forming the whole with a plastic or a rubber-like elastic body, and may be formed with a hard plastic of the other part. it can. The insulator 3 is formed by insert-molding a soft plastic or rubber-like elastic body into a hard plastic. For example, the soft plastic or the rubber-like elastic body forms a portion that comes into contact with a support rib of a holder case in which the assembled battery is provided. 6 and 10
Since the insulator 3 shown in FIG. 3 abuts the cylindrical cap 3A against the support rib, this portion is formed of a soft plastic or rubber-like elastic material, or a protruding portion provided on the surface of the cylindrical cap. From a soft plastic or rubber-like elastic body.

The inner shape of the cylindrical cap 3A of the insulator 3 is substantially equal to the outer shape of the end of the battery 2, and
Are connected to the battery 2. In the case of an insulator in which the cylindrical cap is formed of a soft plastic or rubber-like elastic body that can be elastically deformed, the inner shape of the cylindrical cap is formed slightly smaller than the outer shape of the battery. The insulator is connected to the cylindrical cap in a state where the end of the battery is inserted into the cylindrical cap and the cylindrical cap is elastically pressed against the surface of the battery. Therefore, there is a feature that the insulator can be connected to the battery without falling off.

[0031]

EXAMPLES [Example] A single type nickel-hydrogen battery was used as the battery 2 and the thickness of the plate 1A was 0.8 mm and the thickness of the welded portion 1B was 0.5 mm for the connection fitting 1. When the two batteries 2 were connected in series and the resistance of the connection part of the connection fitting 1 was measured, the value was extremely low at 0.09 mΩ.

[Comparative Example] For comparison, two batteries were connected in series with the connection fitting in the same manner as in the example except that the entire thickness of the connection fitting was 0.5 mm. When the resistance of the connection part of the metal fitting was measured, it was 0.12 mΩ. Since the resistance of the example is 0.09 mΩ, the structure of the example can reduce the resistance of the connection portion of the connection fitting by 25%.

[0033]

According to the battery pack of the present invention, the number of parts is small.
The battery can be easily and easily connected with a low resistance, and the manufacturing cost can be reduced and the battery can be securely connected. That is, in the battery pack of the present invention, a connection fitting for connecting a plurality of batteries in a straight line is used as a cap for pressing an elastic body of a safety valve provided on a sealing plate of the battery. This is because adjacent batteries are connected linearly. In the battery pack having this structure, the connection fitting is used in combination with the cap for pressing the elastic body of the safety valve. For this reason, the connection metal fitting is fixed to the end face in the assembled state. This connection fitting can connect a plurality of batteries in a straight line only by welding to one of the batteries without welding to both of the adjacent batteries, unlike a conventional dish-shaped connection fitting. As described above, the assembled battery according to the present invention, in which the number of welded portions can be reduced, can be mass-produced efficiently by reducing the resistance of the connection portion and reducing the time required for welding the connection fitting. Further, since the assembled battery of the present invention does not use a connection fitting specifically designed for connecting the battery, the assembled battery has a feature that the number of parts can be reduced and the production can be performed at low cost.

Further, in the battery pack of the present invention, the welded portion is formed in a flange shape protruding toward the bottom surface of the battery to be welded, and the flange-shaped welded portion is welded to the bottom surface of the battery to reduce the resistance. In addition, there is a feature that can give a neat appearance.

Further, in the battery pack of the present invention, the welded portion of the connection fitting is formed in a cylindrical shape into which the end of the battery to be welded can be inserted, and the tubular welded portion is welded to the side surface of the outer can. It has the advantage that the weld can be easily welded to the outer can.

Further, in the assembled battery of the present invention, a plurality of batteries can be easily and reliably connected by providing a projection at the welded portion of the connection fitting and welding the projection to the battery.

[Brief description of the drawings]

FIG. 1 is a perspective view of a plate-shaped connection fitting used in a conventional battery pack.

FIG. 2 is a side view of the dish-shaped connection fitting shown in FIG. 1;

FIG. 3 is a sectional view showing a state in which cylindrical batteries are connected using the dish-shaped connection fitting shown in FIG. 1;

FIG. 4 is a side view of a conventional assembled battery in which cylindrical batteries are connected by a dish-shaped connection fitting.

FIG. 5 is a side view showing a connection state between the battery and the connection fitting of the battery pack according to the embodiment of the present invention.

FIG. 6 is an enlarged cross-sectional view showing a connection state between a battery and a connection fitting of the battery pack shown in FIG. 5;

FIG. 7 is a perspective view of the battery pack shown in FIG. 5;

FIG. 8 is a perspective view of an assembled battery according to an embodiment of the present invention.

FIG. 9 is a side view showing a connection state between a battery and a connection fitting of a battery pack according to another embodiment of the present invention.

FIG. 10 is an enlarged sectional view showing a connection state between the battery and the connection fitting of the battery pack shown in FIG. 9;

FIG. 11 is a perspective view of a battery pack according to another embodiment of the present invention.

[Explanation of symbols]

1: Connection fitting 1A: Plate part 1
B: welded part 1a: pressed part 1b: fixed part 1c: holding part 2: battery 3: insulator 3A: cylindrical cap 3
B: insulating plate portion 4: outer can 5: sealing plate 5A: concave portion 5
B ... Valve hole 8 ... Removal part 9 ... Cap 10 ... Safety valve 11 ... Elastic body 12 ... Valve body 13 ... Projection 21 ... Connecting fitting 21A ... Plate part 2
1B: Side wall portion 22: Cylindrical battery 23: Projection 24: Outer can

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Takashi Oda 2-5-5 Keihanhondori, Moriguchi-shi, Osaka F-term in Sanyo Electric Co., Ltd. (Reference) 5H012 AA01 DD03 GG07 JJ02 5H022 AA19 BB03 CC02 CC09 CC12 CC13

Claims (7)

[Claims] An assembled battery in which a plurality of batteries (2) are linearly connected via a connection fitting (1), wherein the connection fitting (1) is provided on a sealing plate (5) of the battery (2). The cap (9) pressing the elastic body (11) of the safety valve (10) is provided with a welding portion (1B) for welding to the battery (2), and the welding portion (1B ) To the battery (2)
An assembled battery comprising (2) connected in a straight line. 2. The connecting member (1) is connected to an elastic body (1) of a safety valve (10).
1) a pressing portion (1a), a fixing portion (1b) outside the pressing portion (1a), and a welding portion outside the fixing portion (1b).
(1B), wherein the fixing portion (1b) is fixed to the sealing plate (5) of the battery (2). 3. The welded portion (1B) has a flange shape projecting toward the bottom surface of the battery (2) to be welded, and the flanged welded portion (1B) is welded to the bottom surface of the battery (2). The battery pack according to claim 2, wherein 4. The flange-shaped welded portion (1B) protrudes from the pressing portion (1a), and the height at which the welded portion (1B) protrudes from the pressing portion (1a) is 5 mm or less. The battery pack described in 1. 5. The battery pack according to claim 3, wherein the flange-shaped welding portion (1B) and the pressing portion (1a) are located on the same plane. 6. The welding portion (1B) has a cylindrical shape into which an end of a battery (2) to be welded can be inserted, and the welding portion (1B) is welded to a side surface of an outer can (4). The battery pack described in 1. 7. The assembled battery according to claim 1, wherein a projection (13) is provided at the welding portion (1B), and the projection (13) is welded to the battery (2).