KR100292608B1 - Battery pack - Google Patents

Abstract

The present invention relates to a battery pack including a secondary battery capable of multiple charge / discharge cycles, such as a lithium ion secondary battery, and a means for controlling the state of charge and discharge of the battery, while maintaining stability and durability as a battery pack. In order to provide a battery pack that is more accurately downsized and lighter than before, a battery body, an electronic circuit for controlling a charge / discharge state of the battery body on an outer circumferential surface of the battery body, and a protective member surrounding the outer circumference of the electronic circuit are provided. In addition, the battery body has at least one flat component attaching surface, and arranges the components constituting the electronic circuit on the component attaching surface in close contact with each other, while the first member and the component attaching surface of the protective member are substantially parallel to the component attaching surface. It was set as the structure provided with the 2nd surface continuous with the surface adjacent to a surface.

This construction effectively protects the electronic circuits while miniaturizing, reducing the thickness and weight of the battery pack, protecting the lead wires and the electrode portions, and at the same time ensuring the attachment state of the protective member to the battery body. It can be stabilized, facilitates assembly as a battery pack, reduces the number of parts, and is electrically quadruple to protect electrical protection regardless of the configuration of a simplified protection member. .

Description

Battery pack

1 is an exploded perspective view of a battery pack according to the present invention;

2 is a perspective view illustrating an assembled state of a battery pack;

3 is a partially enlarged cross-sectional view taken along a line A-A in FIG. 2;

4 is an enlarged cross-sectional view taken along the B-B line direction in FIG. 2;

Fig. 5 is a block diagram showing the configuration of an electronic circuit, and Fig. 6 is a waveform diagram illustrating the operation when charging the electronic circuit.

* Detailed description of the simple signs in the drawings

10: battery pack, 12: battery body,

16: protective member, 18: the upper surface of the battery body,

20: positive electrode of the battery body, 24: negative electrode of the battery body,

26: circuit board, 28: electronic circuit components,

30: electronic circuit, 32: switching circuit,

34: protection control circuit, 36: charge control circuit,

38: power supply control circuit, 40: temperature fuse,

42: first switching element, 44: second switching element,

46: third switching element, 48: fourth switching element,

64: double-sided adhesive tape, 68: first circuit component group,

70: second circuit component group, 72: component attachment surface,

74: first surface of the protective member, 76: second surface of the protective member,

80: step of the protection member, 82: side of the battery body,

84: top plate, 86: the bottom surface of the battery body,

88: lower plate, 90: electrode,

92: lead wire, 98: mounting plate.

[Purpose of invention]

[Technical field to which the invention belongs and the prior art in that field]

The present invention relates to a battery pack including a secondary battery capable of multiple charge and discharge, such as a lithium ion secondary battery, and a means for controlling the state of charge and discharge of the battery.

In general, in a secondary battery having a large charge / discharge energy such as a lithium ion secondary battery, overcharging or overdischarging causes deterioration of the battery and itself, so that a protection circuit is integrated to increase the safety and reliability of the battery. It is often provided as assembled.

By the way, this type of secondary battery is generally handled by children and the elderly, and in the conventional case, in order to protect the protection circuit itself not only electrically but also physically, specially designed a case housing the battery and the protection circuit integrally, and It has been considered that it is necessary to provide a necessary member in a state in which it is stored.

[Technical problem to be achieved]

However, as miniaturization of portable electronic devices progresses, there is a great demand for miniaturization of secondary batteries used therein. However, the presence of the casing is a hindrance to miniaturization of batteries.

The present inventors conducted research in view of such a problem, and as a result, the electronic circuit components were placed in close contact with one surface on the battery main body and surrounded and protected only by the electronic circuit components. It has been found that durability is sufficiently guaranteed.

SUMMARY OF THE INVENTION An object of the present invention is to provide a battery pack capable of accurately miniaturization and weight reduction compared to the prior art while maintaining safety and durability as a battery pack.

[Configuration of Invention]

1 and 2, the battery pack 10 according to the present invention is charged to the battery body 12 on the battery body 12, the outer peripheral surface of the battery body 12. An electronic circuit 30 for controlling the discharge state and a protective member 16 surrounding the outer circumference of the electronic circuit 30 are provided. In the present invention, the battery main body 12 also has at least one flat component attaching surface 72, and the article 28 forming the electronic circuit 30 is closely adhered to the component attaching surface 72. And a second surface that is continuous with the first surface 74 substantially parallel to the component attaching surface 72 and the surface 82 adjacent to the component attaching surface 72 on the protective member 16. It is characterized by including 76.

In addition, when the battery main body 12 is a rectangular shape consisting of four rectangular cylindrical side surfaces and upper and lower cross-sections having positive electrodes, the electronic circuit component 28 may be replaced by the battery main body 12. The protective member 16 can be formed in a shape that continuously covers the side surface on which the electronic circuit component 28 is disposed and the upper and lower cross sections while being disposed on one side surface of the substrate.

Further, as shown in FIG. 3, the first component group 68 having a small thickness when the electronic circuit component 28 is disposed on the battery body 12 and the second component group 70 larger than the electronic circuit component 28 are shown. In addition, while the arrangement position on the side of the battery body 12 is different from each other, the first surface 74 of the protective member 16 is the first and second component groups 68, By setting the separation distance from the component attaching surface 72 corresponding to the thickness of 70, the battery pack 10 can be prevented from being inserted upside down. Also, by using the protective member 16 as the circuit board 26 of the electronic circuit component 28, the overall size of the battery pack can be further reduced.

5 and 6, when the terminal voltage at the time of charge / discharge of the battery body 12 exceeds the first upper limit voltage ＶＵ1, charging is stopped and the first lower limit is set. The first control means enabling pulse charging to resume charging when the voltage is lower than the voltage L1, and when the terminal voltage at the time of charging the battery body 12 exceeds the second upper limit voltage ＶＵ2 which is larger than the first upper limit voltage ＶＵ1. Second control means for forcibly stopping charging; stopping the energization of the first and second control means when the externally charged voltage exceeds the third upper limit voltage ＶＵ3 higher than the second upper limit voltage ＶＵ2. The third control means and the fourth control means for forcibly stopping the energization of the battery main body 12 when the surface temperature of the battery main body 12 exceeds the set value, thereby electrically quadruple protectionPhysical protection for the simplification of the arc member 16 can be compensated precisely.

[Examples of the Invention]

Hereinafter, although the battery pack which concerns on this invention is demonstrated according to the example which performed each lithium ion secondary battery of each type, it cannot be overemphasized that this can be performed substantially similarly about the secondary battery of various shapes or forms. .

In the battery pack 10 according to the present invention, as shown in FIG. 1 and FIG. 2, the battery pack 12 performs an electronic control for controlling the charge / discharge state of the battery body 12 and the battery body 12. It consists of a protection member 16 which covers the periphery of the circuit 30 and the electronic circuit 30.

The battery body 12 is a lithium ion secondary battery formed in a rectangular cylindrical shape, protruding the cylindrical positive electrode 20 at a slightly eccentric position on the upper surface 18 and at the same time the front surface of the upper surface 18. By covering the entire surface with the insulating plate 22, leaving a portion of the positive electrode 20, the other surface in the outer circumference of the battery body 12 is insulated from the positive electrode 20 to form the negative electrode 24, In the following, a plurality of charge / discharge cycles are possible via the electronic circuit 30 describing the configuration in detail.

The electronic circuit 30 is configured as shown in FIG. 5 by arranging the necessary electronic circuit components 28 on the circuit board 26. The electronic circuit 30 is inserted in series in the energization path to the battery main body 12 so as to supply the energization timing. Regulating switching circuit 32; A protection control circuit 34 which detects an overcharge, an overdischarge, or an overcurrent state during charge and discharge to protect the battery body 12; A charging control circuit 36 for executing control for maintaining the terminal voltage of the battery body 12 at the time of charging at a set value; A power supply control circuit 38 for stopping the input when the charging voltage is ideally high and protecting the protection control circuit 34 and the charging control circuit 36; It consists of a temperature fuse 40 for detecting and melting the overheated state of the battery body 12.

The switching circuit 32 is formed by the first and second switching elements 42 and 44, the charge control circuit 36 and the power supply control circuit 38, which are turned on and off by the protection control circuit 34. And third and fourth switching elements 46 and 48 which perform on-off control. Here, the first to third switching elements 42, 44, 46 are connected to the negative electrode 24 of the battery body 12 after the FET is used and the source and drain elements are connected in series. Insertion in series in the charge / discharge circuit on the side enables direct on / off regulation of the energization of the battery body 12.

That is, the first switching element 42 is for regulating the discharge time, connecting the gate terminal to the discharge control terminal 50 of the protection control circuit 34, and at the same time charging the diode 54 between the source drains. The connection can be performed so that charging can be performed irrespective of whether the switching element 42 is turned on or off, but only when the discharge on signal is output from the protection control circuit 34 so as to be discharged.

In contrast, the second switching element 44 connects its gate terminal to the charge control terminal 52 in the protection control circuit 34 and at the same time connects the diode 56 between the source and drain in the discharge direction. Thus, discharge can be performed regardless of the switching element 44 being turned on or off, but the charging control signal 34 outputs the charging on signal so that the charging can be performed only when it is turned on.

In addition, the control contents in the protection control circuit 34 are substantially the same as in the prior art, and overdischarge is detected when the terminal voltage of the battery body 12 at the time of discharge falls below the set value. When overcurrent is detected by the discharge current exceeding a set value, the first switching element 42 is turned off to forcibly stop the discharge. On the contrary, when overcharge is detected by the charging voltage of the battery main body 12 exceeding the upper limit value or when the overcurrent is detected because the charging current exceeds the set value, the second switching element 44 is turned off forcibly to charge. Although the electrical protection is provided to the battery main body 12 by stopping, the control content is not limited.

Next, the third switching element 46 connects the diode 58 in the discharge direction between the source and the drain, connects the gate terminal to the power supply line on the positive (+) side through the resistor 60, and simultaneously And a fourth switching element 48 made of an NPN transistor between the source terminal and the source terminal, and a charge control signal output from the charge control circuit 36 is applied to the base end of the fourth switching element 48. With this configuration, the application of the on signal via the resistor 60 is executed in conjunction with the application of the charging voltage from the outside of the circuit so that the third switching element 46 is turned on, but the charge control circuit 36 turns off the signal. Is output, the third switching device 46 indirectly passes through the fourth switching device 48 by turning on the fourth switching device 48 and shorting off the gate-source of the third switching device 46. Controlled on / off.

Here, in the charging control circuit 36, as shown in Fig. 6, the first upper limit voltage # 1 and the lower limit voltage XL1 are set in a relatively narrow range, for example, 4.08 [k] and 4.10 [k], and the upper limit thereof. When the voltage # 1 is exceeded, the terminal voltage of the battery main body 12 is approximately 4.9 by executing the on-off control operation as illustrated by the solid line which outputs the off signal for charging and stops the off signal when the voltage is lower than the lower limit voltage L1. Pulse charging in the state held at [k] is performed. On the other hand, in the above-described protection control circuit 34, for example, about 4.05 [kV] slightly lower than the second upper limit voltage # 2 and the first lower limit voltage L1 of about 4.25 [kV], which are sufficiently higher than the first upper limit voltage # 1. Even when the control operation of the charge control circuit 36 is difficult to be achieved by setting the second lower limit voltage FL2 of the circuit, the protection control circuit 34 executes the charge control operation as illustrated by the dashed-dotted line. To make it possible.

Also, a Zener having a threshold value of about 6.8 [kV], which is sufficiently higher than the charging voltage of the battery body 12 between the base end and the plus pole of the fourth switching element 48, for example, the third upper limit voltage ＶＵ3. By connecting the diode 49 as the power supply control circuit 38, the zener diode 49 is immediately turned on even when the charging device is wrong and a very high charging voltage is externally applied to the battery pack 10. 4 the switching element 48 is turned on and the third switching element 46 is turned off by the on operation thereof to stop the energization at the inlet side of the battery pack 10 so that the protection control circuit 34 and the charging control circuit 36 are turned off. The damage caused by the application of the overvoltage is prevented in advance.

In addition, since the temperature fuse 40 is connected in series with the battery main body 12, all of the control circuits 34, 36, and 38 described above do not operate well, and thus the battery main body 12 is overcharged or overcurrent. Even in the case of the state, when the battery body 12 rises above the set temperature, the thermal fuse 40 blows out, and the battery body 12 is finally protected.

In addition, the capacitor 62 connected to each location is used, for example, a relatively large one of about 0.1 [μF], and bypasses the noise to prevent the electronic circuit 30 from malfunctioning.

In addition, although the protection control circuit 34 and the charge control circuit 36 are all integrated circuits of one chip, when the physical or electrical characteristics different from each other, such as CMOS, N-channel MOS, or TLC, are used, static electricity or physical shock may occur. Due to this, it is possible to prevent both control circuits 34 and 36 from being damaged at the same time.

The electronic circuit 30 configured as described above is formed on a thin band-shaped circuit board 26 whose width is slightly smaller than the width of one side surface of the battery body 12 set on the component attachment surface 72. The required electronic circuit components 28 are soldered and then adhesively fixed on the corresponding side surfaces 72 via insulating double-sided adhesive tape 64.

However, since the temperature fuse 40 of the electronic circuit component 28 needs to directly detect the surface temperature of the battery body 12, a cutout 66 having its shape is provided on the circuit board 26 and the The temperature fuse 40 is inserted. The first circuit component group 68 such as the temperature fuse 40 having a small height from the bottom surface of the circuit board 26 and the second circuit component group 70 such as a large integrated circuit chip are illustrated in FIG. 3. As illustrated in Fig. 1, the circuit board 26 is arranged in a vertical direction.

Meanwhile, as shown in FIGS. 3 and 4, the protection member 16 protecting the electronic circuit 30 has a first surface having a size covering the whole of the component attaching surface 72 set in the battery body 12. The first surface of the protection member 16 is provided by providing the second surface 76a, 76b which orthogonally crosses 74 and its 1st surface 74, and covers both sides of the electronic circuit 30 in the longitudinal direction. The electronic circuit 30 is accommodated in the space 78 surrounded by the 74, the second surface 76, and the component attaching surface 72 of the battery body 12.

In the case where the step 80 is formed on the first surfaces 74a and 74b to correspond to the thickness of the electronic component group on the electronic circuit board 26, the battery pack is constructed as a battery pack. It is prevented from being inserted backwards in the long direction. On the other hand, as shown in Figs. 2 and 4, the second surface 76 is formed so as to be continuous with the component attaching surface 72 and the side surface 82 in the lateral direction, thereby protecting the battery body 12. When the member 16 is affixed, it is made to bond with the battery main body 12 in the coplanar state, without the step which arises between the protection member 16 and the battery body 12.

In the present invention, basically, as described above, only the electronic circuit portion is protected, so that the minimum protection as the battery pack can be achieved. However, in the present embodiment, the upper plate 84 covering the upper surface 18 of the battery body 12 and the lower plate 88 covering the lower surface 86 are described above at the end of the protective member 16. By forming integrally with the synthetic resin material in the shape combined with the structure, the battery body of the protection member 16 can be protected at the same time as the protection of the lead wire 92 portion of the electrode 90 extending from the electronic circuit 30. It is assumed that attachment to 12) is stronger.

Here, the lower plate 88 is a thin plate shape covering the entire lower surface 86 of the battery body 12, and the negative electrode (90) side electrode 90b extending from the circuit board 26 side of the battery body 12 While being held and fixed between the bottom surface 86 of the c), the negative electrode 90b can be exposed to the outside of the battery pack 10 through a small diameter opening 94 provided at the center thereof. To make it work.

In addition, the upper plate 84 prevents the portion of the lead wire 92 of the positive electrode 90a extending from the upper edge side of the circuit board 26 in contact with the negative electrode 24 of the battery body 12. The lead wire 92 is connected to the positive electrode 20 of the battery body 12, and the electrode 90a can be fixed to the center of the battery body 12 in the center of the upper plate 84. The positive side electrode 90a is led out of the battery pack 10 through the provided opening 96.

형상의 중간판(102)를 마련하는 것에 의해, 그 중간판(102)의 상면에 전극 (90a)를 탑재하고 상부판(84)의 하면 사이에 끼워 유지해서 단자대(104)로 하는 한편, 중간판(102)의 하면과 부착판(98) 사이에 형성한 중간케이스(106)에서 전극(90a)에 이르는 리이드선(92) 부분을 전지팩(10)의 외부와 격리시켜 보호하고 있다.In order to achieve this purpose, in this embodiment, the L-shaped attachment plate 98 and the upper plate 84 adhered to and fixed on the insulating plate 22 on the upper surface 18 side of the battery body 12. By forming the upper case 100 as shown in Figure 3 and at the same time in the upper case 100

By providing the intermediate plate 102 in the shape, the electrode 90a is mounted on the upper surface of the intermediate plate 102 and sandwiched between the lower surfaces of the upper plate 84 to be the terminal block 104. A portion of the lead wire 92 extending from the intermediate case 106 formed between the lower surface of the plate 102 and the attachment plate 98 to the electrode 90a is isolated and protected from the outside of the battery pack 10.

The battery pack 10 configured as described above can be used as it is when assembled in an electronic device. However, in the case where separation is performed to the general consumer, the protection member is also provided by enclosing at least portions of the upper and lower openings 94 and 96 and enclosing the circumferential surface portion with a heat shrink tube that is substantially the same as in the prior art not shown. Unnecessary separation of the battery body 12 from the battery body 12 can be prevented as much as possible.

In addition, in the case where the electronic circuit portion can be designed to be more compact, the electronic circuit 30 and the upper surface 18 or the lower surface 86 instead of being attached to the side surface of the battery body 12. The protection member 16 which protects it can be arrange | positioned. In this case, the battery body 12 can also be implemented in a cylindrical shape. Instead of attaching the electronic circuit component 28 to the battery body 12 via the circuit board 26, the electronic circuit component 28 is directly attached on the circumferential surface of the battery body 12 and the configuration of the circuit board 26 is described above. By making it substantially the same as one protection member 16, a protection member and a circuit board can also be used.

In addition, instead of providing one protective member 16 for one battery body 12 as described above, the component attaching surfaces 72 of the plurality of battery bodies 12 are arranged in parallel in the horizontal direction. It is also possible to cover the whole with one protection member 16 in the state provided.

[Effects of the Invention]

In the present invention, since the electronic circuit 30 is provided on one surface on the battery body 12 as described above, and only the electronic circuit portion is surrounded by the protective member 16, the protection of the electronic circuit 30 is prevented. Effectively, the battery pack can be reduced in size, thickness, and weight accurately.

In addition, the lead wire 92 and the electrode are formed by providing the electronic circuit 30 on one side surface 72 and forming the protection member 16 in an '@' shape that covers the upper and lower end surfaces of the battery body 12. It is possible to protect the portion 90 and at the same time make the attachment state of the protective member 16 to the battery body 12 more stable. In addition, by using the protective member 16 as the circuit board 26 of the electronic circuit 30 and placing the parts in close contact with the battery main body 12, the assembly as the battery pack 10 can be easily performed. In addition, it is possible to reduce the number of parts and at the same time make it possible to further reduce the weight.

In addition to the conventional protection circuit 34 and the temperature fuse 40 as the electronic circuit 30, a circuit 36 for performing pulse charging and a voltage exceeding a specified level from outside are bypassed. By including a circuit 38 to prevent the battery body 12 from being applied to the inside of the battery pack, the battery body 12 is electrically protected four times, so that the electrical protection can be accurately achieved regardless of the configuration of the simplified protection member 16. Can be.

Claims (5)

Battery body; An electronic circuit device for controlling a charge / discharge state of the battery body; A protective member attached to the battery body to cover the electronic circuit device, the battery body having at least one flat component attaching surface, the electronic circuit device including a plurality of electronic circuit parts, and the electronic The circuit device is attached on the flat part attaching surface by the electronic circuit component in close contact with the flat part attaching surface, and the protective member has a rectangular flat member and a side flange projecting vertically at the opposite end of the flat member. And a space for accommodating the electronic circuit device therein when the protective member is fitted to the component attaching surface. The battery body of claim 1, wherein the battery body is configured to have four side surfaces, an upper surface and a lower surface, and one of the side surfaces includes the component attaching surface, and the protective member is integrally formed with the rectangular flat member. And an upper end plate and a lower end plate extending vertically at each opposite end of the rectangular flat member, wherein the upper end plate and the lower end plate cover upper and lower end surfaces of the battery body. The electronic circuit component according to claim 1 or 2, wherein the electronic circuit component is divided into a first group and a second group of electronic circuit components, and the electronic circuit components of the first group have a thickness or greater than that of the second group of electronic circuit components. Small in size, the first group of electronic circuit components is covered by one half of the rectangular flat member, and the second group of electronic circuit components is covered by the other half of the rectangular flat member. And the rectangular flat member is separated from the component attaching surface by a distance determined corresponding to each size or thickness of the electronic circuit components of the first group and the second group. The battery pack as claimed in claim 1, wherein the protection member is a circuit board for supporting the electronic circuit component. The battery body according to claim 1, wherein the electronic circuit device stops charging the battery body when the voltage at the time of charging the battery body exceeds the first upper limit voltage, and when the voltage of the battery body is lower than the first lower limit voltage. First control means for enabling the charging of. Second control means for forcibly stopping charging of the battery body when the voltage at the time of charging the battery body exceeds the second upper limit voltage which is greater than the first upper limit voltage; Third control means for stopping the energization of the first and second control means when the voltage supplied from the outside exceeds the third upper limit voltage higher than the second upper limit voltage; A battery pack for the purpose of having a fourth control means for forcibly stopping the energization of the battery body when the surface temperature of the battery body exceeds the set value.

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