JP3877638B2 - Battery pack - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a battery pack in which a plurality of cylindrical batteries are arranged in parallel.
[0002]
[Prior art]
A battery pack in which a plurality of cylindrical batteries are arranged in parallel is provided with spacers in the valleys between the batteries in order to arrange the batteries in a fixed position as described in JP-A-50-70832. is doing. The spacer has a battery mounting surface along the surface of the cylindrical battery, and the cylindrical battery is brought into contact therewith to fix the adjacent cylindrical battery in place. Furthermore, the battery pack incorporating a plurality of batteries connects the batteries in series or in parallel. Connecting the batteries in series or in parallel can be realized by connecting the electrodes on the end faces of the adjacent batteries with leads. When the battery positive and negative directions are arranged in the same manner and the battery end faces are connected by leads, the batteries are connected in parallel. Moreover, when the battery end faces are connected with leads by arranging the batteries so that the positive and negative directions are reversed, the batteries are connected in series. This connection structure can connect batteries in series with short leads.
[0003]
[Problems to be solved by the invention]
However, depending on the type of battery incorporated in the battery pack, for example, a lithium ion secondary battery or the like needs to detect each battery voltage with a protection circuit to prevent overcharge and overdischarge. A battery pack that realizes this includes a circuit board on which a protection circuit is mounted. The circuit board needs to connect the electrodes of each battery with leads in order to detect each battery voltage. In the battery pack in which the circuit board is disposed at a position facing the battery end face and the positive and negative electrodes of the battery are connected to the circuit board, it is necessary to dispose leads along the cylindrical surface of the battery. Instead of this circuit configuration, for example, a battery pack that connects each battery to an independent output terminal disposed on the end face of the battery also needs to be wired with a lead along the cylindrical surface of the battery. The leads wired on the cylindrical surface of the battery are fixed to the surface of the battery outer can with a tape or the like, or fixed with an adhesive. However, with this structure, the position where the lead is fixed is easily displaced, and it is difficult to fix the lead firmly in a fixed position. Furthermore, in order to insulate the lead from the battery outer can, it is necessary to sandwich an insulating sheet or the like between the battery outer can and the lead. For this reason, there is a drawback that the wiring of the lead takes more time.
[0004]
The present invention has been developed for the purpose of solving such drawbacks. An important object of the present invention is to provide a battery pack in which leads can be securely wired along a cylindrical surface of a cylindrical battery in a simple and easy manner without causing misalignment. Another object of the present invention is to provide a battery pack in which leads can be insulated from a battery outer can without using a dedicated insulating material.
[0005]
[Means for Solving the Problems]
In the battery pack of the present invention, spacers 3 are arranged between cylindrical batteries 2 arranged in parallel to each other, and adjacent cylindrical batteries 2 are arranged at fixed positions by the spacers 3. The spacer 3 is on a battery mounting surface 31 formed in a shape along a valley formed between adjacent cylindrical batteries 2 and a surface opposite to the battery mounting surface 31, and the lead 6 is It has a lead holding surface 32 provided with either or both of a convex part and a concave part that are held in a fixed position. In the battery pack, the cylindrical battery 2 is brought into contact with the battery mounting surface 31 of the spacer 3 and arranged at a predetermined position, and the lead 6 is positioned at a predetermined position by one or both of the convex portion and the concave portion of the lead holding surface 32. It is arranged.
[0006]
The lead holding surface 32 has a V-groove shape along the valley of the cylindrical battery 2, and a first lead holding surface 32A and a second lead holding surface 32B are provided on two surfaces facing the V-groove shape, The first lead 6A can be disposed on the first lead retaining surface 32A, and the second lead 6B can be disposed on the second lead retaining surface 32B. Furthermore, a convex portion 34 that holds the first lead 6A and the second lead 6B in place can be integrally formed between the first lead holding surface 32A and the second lead holding surface 32B. . The convex portion 34 can reliably prevent the lead 6 from coming off by making the angle between the side surfaces 34A and the first lead holding surface 32A and the second lead holding surface 32B acute. Further, the convex portion 34 can be easily removed from the mold for molding the spacer 3 with both side surfaces 34A being parallel or substantially parallel to each other.
[0007]
Furthermore, in the battery pack of the present invention, the circuit board 4 can be disposed on the end face of the cylindrical battery 2 via the insulating holder 5. In this battery pack, one end of the lead 6 </ b> A can be connected to the circuit board 4 and the other end can be connected to the electrode 2 </ b> A of the cylindrical battery 2. Further, the insulating holder 5 is provided with a battery holding part 53 extending between the adjacent cylindrical batteries 2, and the battery holding part 53 is arranged between the cylindrical battery 2 and the lead 6. Thus, the lead 6 and the cylindrical battery 2 can be insulated. Further, the spacer 3 is formed by integrally forming an end surface cover portion 33 that covers the battery end surface of the cylindrical battery 2, and the end surface cover portion 33 is disposed between the lead 6 and the battery end surface, The end surface cover portion 33 can insulate the lead 6 from the battery end surface.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings. However, the example shown below illustrates the battery pack for embodying the technical idea of the present invention, and the present invention does not specify the battery pack as follows.
[0009]
Further, in this specification, in order to facilitate understanding of the scope of claims, the numbers corresponding to the members shown in the examples are referred to as “the scope of claims” and “the means for solving the problems”. It is added to the member shown by. However, the members shown in the claims are not limited to the members in the embodiments.
[0010]
The battery pack shown in FIG. 1 to FIG. 1 has a plurality of cylindrical batteries 2 built in a case 1. The battery pack shown in the figure incorporates two cylindrical batteries 2 in a case 1. Hereinafter, although the structure of the battery pack incorporating two cylindrical batteries will be described in detail, the battery pack of the present invention can also incorporate two or more cylindrical batteries. A battery pack containing two or more cylindrical batteries has all cylindrical batteries arranged side by side in parallel on the same plane, or a plurality of batteries connected in a straight line to form a battery module. It can be set as the structure arranged in parallel with.
[0011]
The cylindrical battery 2 is a secondary battery such as a lithium ion secondary battery, a nickel-hydrogen battery, or a nickel-cadmium battery. Since the lithium ion secondary battery has a high output voltage, a plurality of built-in batteries can be independently connected to the output terminal 9 to increase the output voltage. In this battery pack, each positive and negative electrode 2A is connected to an independent output terminal 9. Since this battery pack can charge / discharge each battery 2 independently in an optimal state, it has the feature that the life can be extended while maximizing the capacity that can be substantially charged / discharged.
[0012]
The case 1 is made of plastic, and the first case 1A and the second case 1B are connected to each other, and a battery core pack is placed inside. The battery core pack is formed by connecting the circuit board 4 to the battery 2 to form an integral structure. As shown in the sectional view of FIG. 2, the first case 1 </ b> A has an electrode window 11 that exposes the output terminal 9 of the core pack to the outside. As shown in FIGS. 3 and 4, the second case 1 </ b> B protrudes from the peripheral wall 12 and is provided with a locking piece 13. As shown in the plan view of FIG. 5 excluding the second case 1B, the first case 1A is provided with a locking projection 14 that is guided by the locking hole 13A of the locking piece 13 so as to protrude from the inner surface of the peripheral wall 12. ing. The locking projection 14 is inserted into the locking hole 13A of the locking piece 13, and the first case 1A and the second case 1B are connected so as not to come out from each other. In this state, the locking piece 13 is inserted into a narrow gap between the peripheral wall 12 of the case 1 and the cylindrical battery 2 to prevent deformation. Therefore, the first case 1A and the second case 1B are connected so as not to come off without being held in the locked state and releasing the locked state. Further, the first case 1A and the second case 1B shown in the figure are provided with a convex strip 15 and a concave portion 16 along the contact surface of the peripheral wall 12, and are connected so as not to shift by inserting the convex strip 15 into the concave portion 16. Yes.
[0013]
The core pack includes a cylindrical battery 2, a spacer 3, a circuit board 4, and an insulating holder 5, which are integrally connected. The spacer 3 is manufactured by molding an insulating material such as plastic. The spacer 3 is disposed between the cylindrical batteries 2 disposed in parallel to each other, and the adjacent cylindrical batteries 2 are disposed at fixed positions. The spacer 3 is provided on a battery mounting surface 31 formed in a shape along a valley formed between adjacent cylindrical batteries 2 and a surface opposite to the battery mounting surface 31, and the lead 6 And a lead holding surface 32 for holding in a fixed position. The spacer 3 contacts the battery mounting surface 31 with the cylindrical battery 2 to place the battery in a predetermined position, and the lead holding surface 32 has the lead 6 to hold it in a predetermined position.
[0014]
The spacer 3 has a total length extending from the vicinity of one end of the cylindrical battery 2 on which the circuit board 4 is disposed to the other end. In this way, the long spacer 3 can firmly fix the two cylindrical batteries 2 in place. However, the spacer does not necessarily need to be long in this way. Although not shown, a plurality of spacers can be arranged in the vertical direction of the battery to fix the cylindrical battery and the lead.
[0015]
As shown in FIG. 4, the spacer 3 is integrally provided with an end surface cover portion 33 that covers the battery end surface of the cylindrical battery 2 at one end. The end surface cover portion 33 is disposed between the lead 6 and the battery end surface, and insulates the lead 6 from the battery end surface. The end surface cover portion 33 covers and insulates the battery end surface opposite to the side where the circuit board 4 is disposed. This spacer 3 can reliably prevent the lead 6 from being in electrical contact with the peripheral edge of the battery end face and short-circuiting.
[0016]
The battery mounting surface 31 of the spacer 3 is a curved surface substantially equal to the curvature radius of the outer can so as to be along the surface of the outer can of the cylindrical battery 2. Since the battery mounting surface 31 is disposed between the valleys of the two cylindrical batteries 2, as shown in FIG. 6, the battery mounting surface 31 is substantially V-shaped and formed into a shape along the cylindrical battery 2.
[0017]
As shown in FIG. 6, the lead holding surface 32 of the spacer 3 is also formed into a V-groove shape along the valley of the cylindrical battery 2, and the two surfaces facing the V-groove shape are formed as the first lead holding surface 32 </ b> A. And the second lead holding surface 32B. The first lead 6A is wired to the first lead holding surface 32A, and the second lead 6B is wired to the second lead holding surface 32B.
[0018]
The lead holding surface 32 is provided with either or both of a convex portion and a concave portion in order to hold the lead 6 in a fixed position. The lead holding surface provided with the convex portion guides the lead between the convex portions and wires the lead in a fixed position. A spacer provided with a recess on the lead holding surface guides the lead to the recess and wires it at a fixed position. Furthermore, the lead holding surface provided with the convex portions on both sides of the concave portion can guide the lead to the concave portion and can be wired in a fixed position.
[0019]
In the spacer 3 shown in FIGS. 5 and 6, a convex portion 34 that holds the first lead 6A and the second lead 6B in place is integrally formed between the first lead holding surface 32A and the second lead holding surface 32B. It is molded and provided. The convex portion 34 in the figure is formed in a rib shape that is long in the lateral direction of the battery 2. One or a plurality of convex portions 34 are provided at both ends of the spacer 3 and in the middle thereof. The spacer 3 in FIG. 5 is provided with two convex portions 34 at both ends and in the middle. In the illustrated spacer 3, elongated ridges 35 are provided outside the leads 6, and the leads 6 are disposed between the long ridges 35 and the protrusions 34. The ridge 35 is provided over almost the entire spacer 3.
[0020]
The rib-shaped convex portion 34 in the drawing is formed into a shape that holds the lead 6 so as not to come off. That is, the rib-shaped convex portion 34 has an acute angle (α) between the side surfaces 34A and the first lead holding surface 32A and the second lead holding surface 32B. The protrusion 34 can reliably prevent the lead 6 from coming off in the direction indicated by the arrow A in FIG. Furthermore, the convex portions 34 have both side surfaces 34A of the convex portions 34 parallel to or substantially parallel to each other so that they can be easily removed from the mold for molding the spacer 3. The term “substantially parallel” refers to a shape in which the mold is removed in the direction indicated by the arrow B and is inclined in the direction of narrowing the width of the convex portion 34 toward the angle at which the mold is removed, that is, in the direction indicated by the arrow B.
[0021]
The lead 6 tends to come out in the direction indicated by the arrow A because the end of the lead 6 is bent toward the center at the end of the cylindrical battery 2 as shown in FIG. This is because these are welded and connected to the electrode 2A. In particular, when a lead plate, which is a metal plate, is used for the lead 6, the lead 6 is deformed only in the direction indicated by the arrow A. This is because the lead plate is deformed in the direction indicated by the arrow A orthogonal to both surfaces, but is not deformed in the direction parallel to both surfaces of the lead plate. In the illustrated battery pack, a metal plate is used for the lead 6, but a metal wire can also be used for the lead. The lead, which is a metal wire, can be wired so as not to be displaced from the lead holding surface 32 by preventing the lead 34 from being deformed in the direction away from the lead holding surface 32 with the convex portions 34 and the elongated ridges 35 shown in the figure.
[0022]
In the core pack of FIG. 7, the circuit board 4 is disposed on the end face of the cylindrical battery 2 via the insulating holder 5. The circuit board 4 mounts an electronic component 7 that realizes a protection circuit for the battery 2. The protection circuit detects the battery voltage to prevent the battery 2 from being overcharged or overdischarged, and cuts off the current when an overcurrent flows through the battery 2. As shown in FIG. 7, the circuit board 4 is a printed board and has a shape that substantially conforms to the outer shape of the battery end face, and is provided with a notch 41 into which the insulating holder 5 is fitted. The circuit board 4 shown in the figure is provided with four connecting portions 42 for connecting the leads 6 by soldering. In the drawing, connecting portions 42 provided at two intermediate positions connect the ends of the leads 6 wired to the lead holding surface 32 of the spacer 3 by soldering. The leads 8 soldered and connected to the connecting portions 42 provided on both side portions are welded and connected to the electrode 2A on the battery end surface of the cylindrical battery 2 disposed to face the circuit board 4. . The circuit board 4 is firmly connected to the cylindrical battery 2 with four leads 6 and 8.
[0023]
The insulating holder 5 fixes the output terminal 9 and is connected to the circuit board 4 by soldering the output terminal 9. As shown in the cross-sectional view of FIG. 2, the output terminal 9 is a metal plate bent in an L shape, fixed through the insulating holder 5, and has a tip protruding through the insulating holder 5. The circuit board 4 is fixed to the connecting portion 43 by soldering. As shown in FIGS. 2 and 4, the insulating holder 5 is disposed between the circuit board 4 and the battery end face of the cylindrical battery 2 to insulate the circuit board 4 from the battery end face. The insulating holder 5 shown in these drawings includes an insulating plate part 51 disposed between the circuit board 4 and the battery end face for insulation, and an output terminal fixing part 52 protruding from the insulating plate part 51 in a right angle direction. The battery holding portion 53 extending between the cylindrical batteries 2 is integrally formed of an insulating material such as plastic.
[0024]
As shown in the rear view of the insulating holder 5 in FIG. 8, the insulating plate portion 51 is formed into a shape that covers almost the entire battery end face, more precisely, a shape that excludes part of both ends of the two battery end faces. ing. Further, the protruding portion 54 shown by cross hatching in FIG. 8 is formed to be slightly thick, and the lead 8 welded to the electrode 2A on the battery end surface is disposed between the protruding portions 54. As shown in the cross-sectional view of FIG. 2, the output terminal fixing portion 52 has a shape that fits into the cutout portion 41 of the circuit board 4, and is fitted here and protrudes to the surface side of the circuit board 4. The output terminal fixing part 52 fixes the output terminal 9 bent in an L shape to the surface.
[0025]
The battery holding part 53 is formed in a rib shape along the cylindrical surface of the cylindrical battery 2 and holds the adjacent cylindrical battery 2 in place. As shown in the plan view of FIG. 5, the battery holding portion 53 extends to between the lead 6 and the cylindrical surface of the cylindrical battery 2 to insulate the lead 6 from the cylindrical battery 2. The insulating holder 5 having this structure can reliably prevent the lead 6 from being brought into electrical contact with the outer can of the cylindrical battery 2 and short-circuiting by the battery holding portion 53.
[0026]
The battery pack in which the leads 6 are wired along the surface of the battery 2 tends to be short-circuited due to the electrical contact between the leads 6 and the outer can at the outer peripheral edge of the battery end surface. In particular, the lead 6 bent and wired at the end face of the battery has a strong tendency. This is because even if the peripheral edge of the battery end face is insulated, the lead 6 comes into strong local contact with the outer can at this portion, and the insulation is easily broken. In the illustrated battery pack, the outer peripheral edge of one battery end surface of the cylindrical battery 2 is insulated by the end surface cover portion 33 of the spacer 3, and the outer peripheral edge of the other battery end surface is insulated by the battery holding portion 53 of the insulating holder 5. Yes. Therefore, there is a feature that the lead 6 wired on the lead holding surface 32 can be extremely effectively prevented from coming into contact with the outer can of the cylindrical battery 2 and short-circuiting.
[0027]
The battery pack having the above structure is assembled as follows.
(1) The tip of the output terminal 9 fixed to the insulating holder 5 is soldered to the connecting portion 43 of the circuit board 4 to connect the insulating holder 5 to the circuit board 4. An electronic component 7 on which a protection circuit or the like is mounted is fixed to the circuit board 4 in the previous step of connecting the insulating holder 5.
(2) The spacer 3 is disposed between the valleys of the two cylindrical batteries 2, the lead 6 is wired on the lead holding surface 32 of the spacer 3, and one end of the lead 6 is aligned with the end surface cover portion 33 of the spacer 3. The bent tip is welded to the electrode 2A of the cylindrical battery 2 by a method such as spot welding or laser welding.
(3) The lead 6 wired to the lead holding surface 32 of the spacer 3 is connected to the circuit board 4 by soldering, and the lead 8 connected to the circuit board 4 by welding is also connected. The circuit board 4 is connected by soldering. In this state, the circuit board 4 is connected to the cylindrical battery 2 via the leads 6 and 8, and the insulating holder 5 is also connected integrally via the circuit board 4 to form a core pack.
(4) Put the core pack in the first case 1A. The insulating holder 5 constituting the core pack is used for positioning as shown in FIG. 5 in order to fix the core pack in a fixed position of the first case 1A, particularly in order to arrange the output terminal 9 at an accurate position. The insertion part 55 is provided. The insertion portion 55 in the figure is an insertion recess 55A provided on both sides of the insulating holder 5 and a through hole 55B provided in the center portion. The first case 1 </ b> A is integrally provided with an insertion convex portion 17 guided by the insertion portion 55 of the insulating holder 5. The insertion convex part 17 of the figure is the insertion rib 17A guided to the insertion concave part 55A, and the insertion rod 17B inserted into the through hole 55B. As described above, the structure in which the insulating holder 5 is fitted to the first case 1A and guided to the fixed position allows the output terminal 9 to be disposed at an accurate position regardless of the dimensional error of the cylindrical battery 2.
[0028]
(5) The second case 1B is connected to the first case 1A, and the core pack is stored in the case 1. The second case 1B is connected by guiding the locking piece 13 to the locking projection 14 of the first case 1A. However, the first case 1A and the second case 1B can be connected by welding or adhering the peripheral wall 12.
[0029]
【The invention's effect】
The battery pack of the present invention has a feature that leads can be securely wired along the cylindrical surface of the cylindrical battery simply and easily and without being displaced. In the battery pack of the present invention, a spacer having a battery mounting surface and a lead holding surface is disposed between cylindrical batteries disposed in parallel to each other, and the cylindrical battery is disposed on the battery mounting surface. This is because the lead is placed at a predetermined position while being brought into contact with the lead holding surface. Since the battery mounting surface of the spacer is formed in a shape along a valley formed between adjacent cylindrical batteries, the adjacent cylindrical batteries can be arranged at fixed positions so as not to be displaced. Furthermore, the lead holding surface of the spacer is on the opposite side of the battery mounting surface, and the lead is disposed at a predetermined position by either or both of the convex portion and the concave portion that hold the lead in a fixed position. Wiring can be performed so as not to be displaced along the cylindrical surface of the cylindrical battery. Therefore, the battery pack of the present invention can easily and easily wire the leads firmly in place so as not to be displaced. Furthermore, since the battery pack of the present invention can insulate the lead from the battery outer can by using a spacer together with the insulating material, there is also a feature that it can be mass-produced efficiently and at a low cost without using a dedicated insulating material. is there.
[Brief description of the drawings]
1 is a perspective view of a battery pack according to an embodiment of the present invention. FIG. 2 is a cross-sectional view of the battery pack shown in FIG. 1 along the line AA. FIG. 3 is a cross-sectional view of the battery pack shown in FIG. Fig. 4 is a cross-sectional view taken along line CC of the battery pack shown in Fig. 1. Fig. 5 is a plan view showing a state where the second case of the battery pack shown in Fig. 1 is removed. Fig. 6 is an enlarged cross-sectional view of the spacer. 7 is a front view of the core pack built in the battery pack shown in FIG. 1. FIG. 8 is a rear view of the insulation holder.
DESCRIPTION OF SYMBOLS 1 ... Case 1A ... 1st case 1B ... 2nd case 2 ... Battery 2A ... Electrode 3 ... Spacer 4 ... Circuit board 5 ... Insulation holder 6 ... Lead 6A ... 1st lead 6B ... 2nd lead 7 ... Electronic component 8 ... Lead DESCRIPTION OF SYMBOLS 9 ... Output terminal 11 ... Electrode window 12 ... Perimeter wall 13 ... Locking piece 13A ... Locking hole 14 ... Locking convex part 15 ... Convex 16 ... Concave 17 ... Inserting convex part 17A ... Inserting rib 17B ... Inserting rod 31 ... Battery Mounting surface 32 ... Lead holding surface 32A ... First lead holding surface 32B ... Second lead holding surface 33 ... End surface cover portion 34 ... Convex portion 34A ... Side surface 35 ... Round 41 ... Notched portion 42 ... Connecting portion 43 ... Connecting portion 51 ... Insulating plate part 52 ... Output terminal fixing part 53 ... Battery holding part 54 ... Projection part 55 ... Insertion part 55A ... Insertion recess part 55B ... Through hole

Claims (5)

A battery in which a spacer (3) is arranged between cylindrical batteries (2) arranged parallel to each other, and an adjacent cylindrical battery (2) is arranged at a fixed position by this spacer (3). A pack,
A battery mounting surface (31) formed in a shape along a valley formed between the cylindrical batteries (2) disposed adjacent to each other, and a spacer (3) on the opposite side of the battery mounting surface (31) A lead holding surface (32) provided with either or both of a convex portion and a concave portion for holding the lead (6) in a fixed position, and a cylindrical battery (31) on the battery mounting surface (31) 2) is brought into contact with and arranged at a predetermined position, Ri Na with a lead (6) in either or both of the projections and recesses of the lead holding surface (32) in place,
The lead holding surface (32) has a V-groove shape along the valley of the cylindrical battery (2) , and the first lead holding surface (32A) and the second lead are formed on the two surfaces facing the V-groove shape. provided the holding surface (32B), the first lead holding surface (32A) of the first lead (6A), the second lead holding surface (32B) is disposed a second lead (6B) ,
A convex portion (34) for holding the first lead (6A) and the second lead (6B) in place is integrally formed between the first lead holding surface (32A) and the second lead holding surface (32B). The angle between both side surfaces (34A) of the convex portion (34) and the first lead holding surface (32A) and the second lead holding surface (32B) is an acute angle, and the convex portion ( both sides (34A) parallel or substantially parallel to and ing the battery pack to each other of 34).   The battery pack according to claim 1, wherein a circuit board (4) is disposed on an end face of the cylindrical battery (2) via an insulating holder (5). The battery pack according to claim 2 , wherein the lead (6) has one end connected to the circuit board (4) and the other end connected to the electrode (2A) of the cylindrical battery (2). The insulating holder (5) has a battery holding part (53) extending between the cylindrical batteries (2) disposed adjacent to each other, and the battery holding part (53) is connected to the cylindrical battery (2). The battery pack according to claim 2 , wherein the battery pack is disposed between the lead (6) and the lead (6) to insulate the cylindrical battery (2). The spacer (3) is integrally formed with an end surface cover portion (33) that covers the battery end surface of the cylindrical battery (2), and this end surface cover portion (33) is provided with the lead (6) and the battery end surface. The battery pack according to any one of claims 1 to 4 , wherein the lead (6) is insulated from the battery end face by an end face cover portion (33).

Images