JP3609662B2 - Pack battery - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a battery pack incorporating a printed circuit board.
[0002]
[Prior art]
A battery pack incorporating a printed circuit board can be equipped with a protection circuit or the like on the printed circuit board. A battery pack with a protective circuit mounted on a printed circuit board can be charged and discharged while preventing overcharging and overdischarging of the battery, so that the battery can be used in an ideal environment. Not only the protection circuit but also a circuit for calculating and displaying the remaining capacity of the battery can be mounted on the printed circuit board.
[0003]
A printed circuit board on which various circuits are mounted needs to be fixed at a fixed position of the case. A battery pack for fixing a printed circuit board to a fixed position of a case with a holder has been developed (JP-A-8-212992). In the battery pack described in this publication, as shown in FIG. 1, the printed circuit board 3 is held by a holder 20 having a guide groove 21 parallel to the facing surface. The holder 20 is disposed on the surface of the cylindrical battery 22 arranged in a plane, and the printed circuit board 3 is inserted into the guide groove 21 of the holder 20.
[0004]
[Problems to be solved by the invention]
The battery pack shown in FIG. 1 can fix the printed circuit board in place with a holder. However, in the battery pack having this structure, since the secondary battery is disposed to face the printed board, the electrolyte solution leaking from the secondary battery causes the printed board to fail. In order to prevent the electrolytic solution from damaging the printed board, it is necessary to provide an isolation plate or the like between the printed board and the secondary battery to isolate the printed board from the secondary battery. In the battery pack having this structure, it is necessary to fix both the printed circuit board and the isolation plate in a fixed position of the case. Since the isolation plate is formed by molding an insulating material such as plastic, it can be easily fixed by being molded into a shape that can be fitted into a fixed position of the case. However, when the isolation plate is disposed between the secondary battery and the printed board, it is difficult to easily electrically connect the printed board to the secondary battery.
[0005]
The present invention was developed to solve this drawback, and an important object of the present invention is to arrange an isolation plate at a predetermined position between the secondary battery and the printed circuit board. In addition, it is an object of the present invention to provide a battery pack in which a secondary battery and a printed circuit board can be easily electrically connected, and further, the printed circuit board can be protected from the electrolytic solution with an isolation plate.
[0006]
[Means for Solving the Problems]
The battery pack according to the present invention includes a case 1, a plurality of secondary batteries 2 that are housed side by side in the case 1, and a print that is disposed between the secondary battery 2 and the inner surface of the case 1. A substrate 3 and an isolation plate 4 formed between the printed substrate 3 and the secondary battery 2 and formed of an insulating material that isolates the printed substrate 3 from the secondary battery 2 are provided. In the battery pack, a plurality of electrode terminals 9 are fixed to the electrodes of the plurality of secondary batteries 2, and each electrode terminal 9 penetrates through a plurality of terminal openings 14 provided in the isolation plate 4 and has a tip end. It is fixed to the printed circuit board 3. The electrode terminal 9 that fixes the end to the secondary battery 2 and the printed circuit board 3 passes through the terminal opening 14 and fixes the isolation plate 4 at a predetermined position between the secondary battery 2 and the printed circuit board 3. doing.
[0007]
The battery pack according to claim 2 of the present invention has the reverse mounting preventing fitting portion 7 that prevents the separation plate 4 and the case 1 from mounting the separation plate 4 to the case 1 in the reverse direction.
[0008]
In the battery pack of claim 3 of the present invention, the isolation plate 4 has a recess 16 into which a part protruding from the printed circuit board 3 is inserted. The recess 16 is provided on the surface facing the printed circuit board 3.
[0009]
The battery pack according to claim 4 of the present invention has a through hole 12 in the vicinity of which the printed circuit board 3 fixes the electrode terminal 9. The electrode terminal 9 having one end fixed to the secondary battery 2 passes through the terminal opening 14 and the through hole 12 of the isolation plate 4 and is fixed to the surface of the printed circuit board 3.
[0010]
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.
[0011]
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.
[0012]
The battery pack shown in the exploded perspective view of FIG. 2 accommodates a plurality of secondary batteries 2 arranged in a plane on a plastic case 1. In the battery pack of this figure, a printed circuit board is disposed on the lower surface of the secondary battery 2, and the printed circuit board is disposed between the secondary battery 2 and the case 1. Further, an isolation plate for isolating the printed circuit board 3 from the secondary battery 2 is disposed between the printed circuit board and the secondary battery 2. FIG. 3 shows an exploded perspective view of the isolation plate 4 and the printed circuit board 3 that are stacked and fixed on one surface of the secondary battery 2. However, FIG. 3 shows a state in which the secondary battery 2 housed in the battery pack shown in FIG. 2 is turned upside down.
[0013]
The case 1 is provided with a lower peripheral wall 8 around the first case 1A that is formed into a thin box shape, and a second case 1B that is formed into a plate shape that can close the opening of the first case 1A. Consists of. The first case 1A has an electrode window 6 that exposes the output terminal of the battery pack. Further, the first case 1A is provided with a fitting convex portion 7A serving as a reverse attachment preventing fitting portion 7 for preventing the separation plate 4 from being attached to the case 1 in the reverse direction on the inner surface of one end portion. The first case 1 </ b> A accommodates a connection unit 5 that connects the secondary battery 2, the isolation plate 4, and the printed board 3. In the first case 1 </ b> A, the shape of the inner surface of the peripheral wall 8 is approximately equal to the outer shape of the isolation plate 4 so that the connection unit 5 can be stored without moving.
[0014]
The secondary battery 2 is a thin lithium ion secondary battery. However, a secondary battery other than the lithium ion secondary battery, for example, a nickel-cadmium battery or a nickel-hydrogen battery can be used as the secondary battery incorporated in the case. In the illustrated battery pack, thin secondary batteries 2 are housed in a case 1 in a horizontal and vertical plane. The illustrated battery pack stores thin lithium ion secondary batteries side by side in 2 × 4 rows. The thin lithium ion secondary batteries are arranged in a plate shape with the wide surfaces positioned vertically in the figure as the same plane.
[0015]
The plurality of secondary batteries 2 are all connected in series or in parallel, or connected in series and in parallel, and the output voltage is set to a voltage suitable for the application. A plurality of electrode terminals 9 are fixed to the electrode of the secondary battery 2 in a state of being electrically connected by a method such as spot welding. The electrode terminal 9 protrudes upward in FIG. 3 in the direction in which the printed circuit boards 3 are stacked and fixed. The secondary battery 2 in FIG. 3 has eight electrode terminals 9 fixed thereto.
[0016]
The printed circuit board 3 is mounted with an electronic component that realizes a protection circuit, a remaining capacity integrating circuit, a circuit that stores an ID for specifying a battery pack, and the like. The printed circuit board 3 shown in the figure also has a temperature sensor 10 for detecting each battery temperature. The temperature sensor 10 detects the battery temperature, and protects the secondary battery 2 by interrupting charging and discharging of the secondary battery 2 when the battery temperature becomes higher than the set temperature. The temperature sensor 10 is attached to a notch 11 provided through the printed circuit board 3. The temperature sensor 10 attached to the notch 11 protrudes from the lower surface of the printed circuit board 3.
[0017]
The printed circuit board 3 is substantially equal in size to the outer shape of the secondary batteries 2 arranged in a plane, and has a through hole 12 in the vicinity of fixing the electrode terminal 9 fixed to the secondary battery 2. The through-hole 12 is opened to a size that can pass through the electrode terminal 9 that cuts the metal plate into a predetermined width. If the through hole 12 is too large, the electrode terminal 9 moves freely in the through hole 12, so that the relative position between the electrode terminal 9 and the printed board 3 cannot be accurately specified. Therefore, the inner shape of the through hole 12 is slightly larger than the cross-sectional shape of the electrode terminal 9 cut laterally, and the electrode terminal 9 can be smoothly inserted, but the inserted electrode terminal 9 is free in the through hole 12. It is opened to a size that does not move. The electrode terminal 9 inserted through the through hole 12 is bent at a right angle on the surface of the printed circuit board 3 or is soldered and fixed to the surface of the printed circuit board 3 without being bent. The printed circuit board 3 in FIG. 3 is also connected to a lead plate 13 connected to the output terminal of the battery pack.
[0018]
The printed circuit board 3 is connected to the secondary battery 2 with the isolation plate 4 sandwiched therebetween. The isolation plate 4 isolates the printed circuit board 3 from the secondary battery 2 and prevents failure of the printed circuit board 3 due to the electrolyte leaking from the secondary battery 2. The isolation plate 4 is formed of an insulating material such as plastic. The isolation plate 4 has a plurality of terminal openings 14 in order to allow the electrode terminals 9 to pass therethrough. The isolation plate 4 is connected to the printed circuit board 3 and the secondary battery 2 so as not to be displaced relative to each other by the electrode terminal 9 inserted through the terminal opening 14. Therefore, the terminal opening 14 is opened at a position through which the electrode terminal 9 passes. The isolation plate 4 of FIG. 3 has eight terminal openings 14 in order to insert the eight electrode terminals 9 fixed to the secondary battery 2.
[0019]
Similarly to the through hole 12 of the printed circuit board 3, the size of the terminal opening 14 is set such that the electrode terminal 9 inserted therethrough cannot freely move. This is because if the terminal opening 14 is too large, the electrode terminal 9 freely moves in the terminal opening 14 and the relative position between the electrode terminal 9 and the isolation plate 4 cannot be accurately specified. Similarly to the through hole 12, the inner shape of the terminal opening 14 is slightly larger than the cross-sectional shape obtained by cutting the electrode terminal 9 horizontally, and the electrode terminal 9 can be smoothly inserted. The terminal opening 14 has a size that does not move freely.
[0020]
However, the isolation plate can also have the structure shown in FIG. The isolation plate 4 has six terminal openings 14 in order to insert the six electrode terminals 9 fixed to the connecting portion of the adjacent secondary battery 2. Further, the two electrode terminals 9 positioned at the tips of the connected secondary batteries 2 are positioned at the edge of the isolation plate 4 without penetrating the isolation plate 4. The electrode terminal 9 located at the tip is connected to the printed circuit board 3 while being bent inward and sandwiching the isolation plate 4 and the printed circuit board 3. This isolation plate 4 is provided with a notch for guiding the electrode terminal 9 at the tip end in the partition wall 15 at the end portion to form a terminal opening 14. These terminal openings 14 are provided at positions where the electrode terminals 9 are bent. The isolation plate 4 of this structure is also connected so as not to be displaced relative to the printed circuit board 3 and the secondary battery 2 by the plurality of terminal openings 14 and the electrode terminals 9 inserted through these terminal openings 14. it can.
[0021]
The isolation plate 4 is formed to have a size facing almost the entire surface of the secondary batteries 2 arranged in a plane, that is, a size substantially equal to the outer shape of the plurality of secondary batteries 2 arranged in a plane. The isolation plate 4 shown in FIG. 2 and FIG. 3 has a length that is equal to the total length of the secondary batteries 2 arranged in four vertical rows and is slightly smaller than the horizontal width of the secondary batteries 2 arranged in two horizontal rows. Yes.
[0022]
The separation plate 4 having a size facing almost the entire surface of the secondary battery 2 is coated with a sealing material between the outer periphery and the inner surface of the case 1, and a gap between the entire periphery of the isolation plate 4 and the inner surface of the case 1. Can be made watertight structure. The isolation plate having this structure can be isolated so that the electrolyte leaked from the secondary battery does not migrate to the printed circuit board. Furthermore, the printed circuit board can be isolated from the secondary battery in an ideal state by filling the terminal opening of the isolation plate with a sealing material and closing the gap between the terminal opening and the electrode terminal with a watertight structure. Silicon rubber or the like can be used as the sealing material.
[0023]
The isolation plate 4 in FIG. 3 is provided with a partition wall 15 around the periphery, and the printed circuit board 3 is disposed inside the partition wall 15. The partition wall 15 has a shape in which the printed circuit board 3 can be fitted inside, in other words, the outer shape of the printed circuit board 3 is substantially equal to the inner shape of the partition wall 15. Further, the separation plate 4 is provided with a fitting concave portion 7B for guiding the fitting convex portion 7A of the case 1 as a reverse mounting preventing fitting portion 7 for preventing the separation plate 4 from being attached to the case 1 in the reverse direction. Yes. Since the fitting convex portion 7A is provided at one end of the case 1, the fitting concave portion 7B is provided at a position for guiding the fitting convex portion 7A.
[0024]
When the isolation plate 4 is attached to the case 1 in a normal posture, the fitting convex portion 7A of the case 1 is guided to the fitting concave portion 7B of the separation plate 4 as shown in the sectional view of FIG. However, when the separator plate 4 is mounted in the reverse direction in the case 1, the fitting convex portion 7A of the case 1 collides with the partition wall 15 of the separator plate 4 as shown in the sectional view of FIG. become unable. The isolation plate 4 is attached to the case 1 in a state of a connection unit 5 that connects the secondary battery 2 and the printed circuit board 3. 5 and 6 show the relative positions of the isolation plate 4 and the case 1, and do not show a state where the isolation plate 4 is actually attached to the case 1.
[0025]
Further, the isolation plate 4 shown in FIG. 3 is provided with a recess 16 for fitting an electronic component protruding from the printed circuit board 3 in the direction of the secondary battery 2 on the surface facing the printed circuit board 3. In the illustrated printed board 3, a temperature sensor 10, which is an electronic component, is provided in the notch 11, and this temperature sensor 10 is projected from the printed board 3 toward the isolation plate 4. The isolation plate 4 has a recess 16 at a position for guiding the protruding temperature sensor 10. The isolation plate 4 is thin at the portion where the recess 16 is provided. Therefore, in this structure, the temperature sensor 10 fixed to the notch 11 on the printed circuit board 3 can be brought close to the surface of the secondary battery 2 through the thinly formed portion of the isolation plate 4. For this reason, there exists the feature which can be fixed to a fixed position as a state which the temperature sensor 10 can detect battery temperature correctly. In particular, since the printed circuit board 3 is close to the secondary battery 2 via the electrode terminal 9, the temperature sensor 10 can be always close to the surface of the secondary battery 2.
[0026]
The battery pack having this structure is assembled in the following steps.
(1) A plurality of secondary batteries 2 are connected in the same plane. As shown in FIG. 3, the secondary battery 2 is connected by attaching a tape 17 to the surface and further connecting the electrode terminal 9 to the electrode by a method such as spot welding. As shown in FIG. 3, the secondary batteries 2 connected to each other are fixed by projecting a plurality of electrode terminals 9 toward the printed circuit board 3.
[0027]
{Circle around (2)} The isolation plate 4 is stacked on the connected secondary battery 2, and the printed circuit board 3 is stacked thereon as indicated by the arrow in FIG. 3. At this time, the electrode terminal 9 having one end fixed to the secondary battery 2 is passed through the terminal opening 14 of the isolation plate 4 and the through hole 12 of the printed board 3.
[0028]
(3) The tip of the electrode terminal 9 is bent at a right angle on the surface of the printed circuit board 3 or fixed to the surface of the printed circuit board 3 by soldering or the like without being bent. At this time, the isolation plate 4 is brought into close contact with the secondary battery 2, and the printed circuit board 3 is brought into close contact with the isolation plate 4. In this state, the secondary battery 2, the isolation plate 4, and the printed circuit board 3 are connected to each other at a predetermined position.
[0029]
(4) As shown in FIG. 2, the connecting unit 5 is mounted in the peripheral wall 8 of the first case 1A, and then the second case 1B is moved to move the first case 1A as indicated by the arrow in this figure. The opening of the is closed. The second case 1B and the first case 1A are welded by ultrasonic waves, heat-welded, or connected via an adhesive.
[0030]
【The invention's effect】
The battery pack of the present invention has an advantage that an isolation plate is disposed at a predetermined position between the secondary battery and the printed board, and the secondary battery and the printed board can be easily electrically connected. This is because the battery pack of the present invention has a plurality of electrode terminals connected to the electrodes of the secondary battery passing through the terminal openings of the isolation plate and fixing the tips to the printed circuit board. In the battery pack having this structure, the electrode terminal for connecting the secondary battery to the printed circuit board fixes the separator plate in place.
[0031]
The battery pack with this structure has an electrode terminal connected to the secondary battery that passes through the terminal opening of the isolation plate and is connected to the printed circuit board by soldering or the like, thereby connecting the isolation plate and the printed circuit board in place. The electrode terminal can be easily and easily connected to the printed board efficiently.
[0032]
Furthermore, since the battery pack of the present invention can wire the electrode terminal connecting the secondary battery to the printed circuit board at the shortest distance, the voltage drop due to the resistance of the electrode terminal is reduced and the voltage of the secondary battery is effectively used. Features that can be output are also realized.
[0033]
Furthermore, the battery pack according to the present invention has an isolation plate disposed between the printed circuit board and the secondary battery, and the printed circuit board is isolated from the secondary battery by this isolation plate, so that the battery leaks from the secondary battery. There is a feature that can minimize the failure of the printed circuit board due to the electrolyte. In particular, the battery pack of the present invention can completely seal the entire circumference of the isolation plate and the terminal opening with silicon or the like, and this structure eliminates the failure of the printed circuit board caused by the electrolyte of the secondary battery. There is a feature that can be.
[Brief description of the drawings]
1 is an exploded perspective view of a conventional battery pack. FIG. 2 is an exploded perspective view of a battery pack according to an embodiment of the present invention. FIG. 3 is an exploded perspective view of a connecting unit of the battery pack shown in FIG. FIG. 5 is a partially enlarged cross-sectional view showing a state in which the isolation plate is attached to the case in a normal posture. FIG. 6 is an illustration in which the isolation plate is reversed. Partially enlarged sectional view showing the state of mounting on the case 【Explanation of symbols】
DESCRIPTION OF SYMBOLS 1 ... Case 1A ... 1st case 1B ... 2nd case 2 ... Secondary battery 3 ... Printed circuit board 4 ... Isolation plate 5 ... Connection unit 6 ... Electrode window 7 ... Reverse attachment prevention fitting part 7A ... Insertion convex part 7B ... Insertion recess 8 ... peripheral wall 9 ... electrode terminal 10 ... temperature sensor 11 ... notch 12 ... through hole 13 ... lead plate 14 ... terminal opening 15 ... partition 16 ... recess 17 ... tape 20 ... holder 21 ... guide groove 22 ... cylindrical battery

Claims (4)

The case (1), a plurality of secondary batteries (2) arranged in a plane in the case (1), and the secondary battery (2) and the inner surface of the case (1) are disposed. And an insulating material disposed between the printed circuit board (3) and the secondary battery (2) to isolate the printed circuit board (3) from the secondary battery (2). A molded isolation plate (4),
A plurality of electrode terminals (9) are fixed to the electrodes of the plurality of secondary batteries (2), and each electrode terminal (9) has a plurality of terminal openings (14) provided in the isolation plate (4). The electrode terminal (9) passing through and fixing the tip to the printed circuit board (3) and fixing the end to the secondary battery (2) and the printed circuit board (3) has a terminal opening (14). A battery pack penetrating and fixing a separating plate (4) at a predetermined position between the secondary battery (2) and the printed circuit board (3). The isolation plate (4) and the case (1) have a reverse mounting preventing fitting (7) that prevents the isolation plate (4) from being mounted in the reverse direction on the case (1). Pack battery. The battery pack according to claim 1, wherein the isolation plate (4) has a concave portion (16) into which a part protruding from the printed circuit board (3) is fitted on a surface facing the printed circuit board (3). The printed circuit board (3) has a through hole (12) in the vicinity of fixing the electrode terminal (9), and the electrode terminal (9) fixing one end to the secondary battery (2) is provided with the isolation plate (4). The battery pack according to claim 1, wherein the battery pack is fixed to the surface of the printed circuit board (3) through the terminal opening (14) and the through hole (12).

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