JP2002117911A - Battery mounted apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a battery mounted apparatus detecting expansion in an anomaly of a battery and preventing fracture or the like of the mounted apparatus. SOLUTION: This battery mounted apparatus mounted with at least one battery inside a battery container is provided in an outer surface of a battery exterior package material with an expansion detecting means generating an expansion detection signal when the battery expands a predetermined size or more and means displaying anomaly and cutting off conductive connection.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a battery-equipped device, and more particularly to a battery pack having a large capacity battery such as a lithium ion battery or a device having such a battery mounted therein due to an abnormality at the time of charging or the like. The present invention relates to a battery-equipped device that prevents a dangerous situation from occurring when an internal pressure rises by detecting a battery abnormality.

[0002]

2. Description of the Related Art In a large-capacity battery such as a lithium ion secondary battery, in order to cope with a short circuit of the battery alone, an abnormality of a protection circuit, or an unexpected situation, an electrolyte or the like is required when the temperature inside the battery rises sharply. , A large amount of gas is generated, and the internal pressure of the battery increases, which may cause an explosion or ignition. Therefore, in such a case, it is necessary to safely release the pressure inside the battery to the outside.

[0003] Therefore, in these sealed batteries,
A thin portion is provided in a part of a battery can, and when the internal pressure exceeds a predetermined size, the internal pressure is released to the outside by breaking the battery can to prevent the battery from exploding. . However, the pressure release due to the cleavage of the thin-walled part takes time until the internal pressure is released, and the internal pressure increases by the time the pressure is released, and the pressure is explosively released. At this time, the battery pack or the battery-equipped device may be distorted.

[0004] In order to solve such a problem, a substance that suppresses a battery reaction due to a rise in battery temperature or a rise in voltage at the time of overcharge is added to a battery electrolyte, or a battery separator is used. Proposals have been made to stop the battery reaction by closing the opening of the separator when the battery temperature rises, but the addition of a substance that does not contribute to the battery reaction in the electrolytic solution inhibits the battery reaction, Or the possibility of reducing the battery capacity cannot be denied. In addition, the use of a special separator has problems such as a decrease in battery capacity and an increase in manufacturing unit cost.

[0005]

SUMMARY OF THE INVENTION It is an object of the present invention to prevent a danger such as an increase in internal pressure of a battery due to an abnormality during charging in a battery having a large capacity such as a lithium ion secondary battery. It is an object of the present invention to detect and respond to an abnormality in a battery at an early stage.

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to provide a battery-equipped device in which at least one battery is mounted in a battery storage space, when the battery expands to a predetermined size or more on the outer surface of a battery outer package. This can be solved by a battery-equipped device provided with an expansion detection means for generating an expansion detection signal.
Also, the present invention is a battery-equipped device having a means for interrupting the conductive connection between the battery and the battery-equipped device or the charging device based on the output of the expansion detecting means. Based on the output of the expansion detection means,
This is a battery-equipped device having a means for displaying an abnormality. A plurality of expansion detecting means; and an expansion determining means for determining expansion of the battery based on signals from the plurality of expansion detecting means, and a conductive connection between the battery and the battery-equipped device or the charging device based on an output result of the displacement determining means. This is a battery-equipped device having a shut-off means for shutting off the battery. The battery-mounted device, wherein the battery is a prismatic battery. Further, in a battery pack containing at least one battery, expansion detection means for generating an expansion detection signal when the battery expands to a predetermined size or more on the outer surface of the battery exterior body, and a detection signal of the expansion detection means. This is a battery pack provided with a cutoff means for cutting off the current supply to the battery. In the above battery pack, the battery is a square battery.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention is intended to prevent a battery such as a lithium secondary battery from expanding when an abnormal condition such as a short circuit occurs and causing the battery to rupture. It is intended to provide a highly-safe battery-equipped device that detects an abnormality in a battery at an early stage of disconnection and disconnects a circuit or avoids an overcurrent state. In addition,
In the present invention, the device using a battery refers to a device using a battery as a power source, but also refers to a device such as a battery pack which is loaded in a container together with a charge / discharge control device and the like in order to use the battery in the device.

The present invention will be described below with reference to the drawings.
FIG. 1 is a diagram for explaining an embodiment of the present invention.
(A) is a perspective view showing a battery pack to which the present invention is applied. The battery pack 1 includes a positive terminal 2 and a negative terminal 3 that are connected to a charging device or a device, and a signal connection terminal 4 for performing various controls with the battery pack. And display means 5 for displaying the state of. FIG. 1B shows a battery pack A
FIG. Inside the battery pack 1, a prismatic battery 6 is held by a holding member 7, and expansion detecting means 8a and 8b are provided on the inner wall surface of the battery pack 1. The battery charge / discharge control, battery protection, and expansion are provided. Detecting means 8a
And a circuit board 9 provided with battery control means for detecting the signals of 8b and 8b. In the event of an abnormality or the like during charging of the battery, the wall surface 10 of the rectangular battery 6 swells and the expansion detecting means 8
a, 8b operate to detect expansion. When the rectangular battery 6 is loaded in the battery pack, the surface having the largest area generally expands when the battery expands, as indicated by the imaginary line 11 when the battery expands, and the central portion of the surface is the largest when the battery expands. It will expand. Therefore, the battery expansion detection means
It is preferable to attach the outer surface of the prismatic battery 6 to a portion facing the center of the surface having the largest area.

FIG. 1B shows an example in which the expansion detecting means is provided on both sides of the battery.
In this example, even when the battery is not expanded, when the expansion detection unit is pressed from the outside, a signal may be detected in the same manner as when the battery is expanded. If there is such a possibility, it is possible to accurately determine only the time of inflation by using expansion detection means that can detect the displacement direction instead of detecting the absolute value of the displacement as the expansion detection means. It becomes possible. Alternatively, a large number of expansion detecting means may be arranged, operations of a plurality of areas having a small area may be detected, and whether or not the expansion has occurred may be determined based on the data. Further, the expansion detecting means and the like may be mounted on a battery pack or mounted on a battery storage section of a device using a battery. As the expansion detecting means, a switch capable of connecting or disconnecting a circuit when a certain displacement occurs, a stress sensor, or the like can be used. Specifically, a low-profile push button switch, a membrane switch, a touch switch, or the like can be used. A switch having a relatively small thickness such as a type switch can be used.

In the above description, an example using a prismatic battery has been described. However, in the present invention, a specific surface greatly expands when the internal pressure increases when the outer surface is flat like a prismatic battery. Although it is suitable for a battery-equipped device using a battery to be used, it can be applied to a device using a battery using a battery of another shape such as a cylindrical flat battery.

FIG. 2 is an exploded perspective view for explaining another embodiment of the present invention. Battery pack 1 has prismatic battery 6 inside a container formed by lower case 12 and upper case 13. The surface having the largest area on the outer surface of the prismatic battery is provided with expansion detection means 8, and the expansion detection means 8
It is connected to a circuit board 9 having protection means for performing charge / discharge control of the battery and protecting the battery and equipment using the battery from abnormalities during charging or discharging. When the expansion detection means 8 detects an abnormality, the protection means provided on the circuit board 9 operates to stop charging and discharging of the battery.

Next, control means provided in the battery-powered device of the present invention will be described. FIG. 3 is a diagram illustrating an example of a control unit provided in the battery-powered device of the present invention. The circuit board 9 has an expansion detecting means interface 14 connected to the expansion detecting means. The expansion detecting section interface 14 has switches mounted on both sides of the rectangular battery to form a closed circuit when the battery expands. 15a and 15b are connected. The expansion detecting means interface 14 is connected to a central control means 16 composed of a microcomputer or the like.
And 15b are activated, the detection signal from the expansion detecting means interface 14 is determined by the determining means 17 provided in the central control means 16, and it is determined that the detection signal is output by the expansion of the prismatic battery. In
The central control means 16 displays on the display unit 18 that there is an abnormality. At the same time, the interface 19 notifies the device using the battery of a signal indicating that the battery is abnormal, and notifies the charge / discharge control unit 20 of the signal indicating that the battery is abnormal. 20 shuts off the external connection circuit 21 with the charging means or the battery device based on the reception of the signal indicating the abnormality. The charge / discharge control means may be provided with means for discharging the energy remaining in the battery by a method such as gradually discharging the battery after stopping.

FIG. 4 is a flowchart for explaining the operation of the control means in the battery-powered equipment of the present invention. When the charging / discharging of the battery in the battery-powered device starts, the charging / discharging control step S2 is started by the starting step S1. If an abnormality occurs in the charge / discharge in the charge / discharge detection step S3, the process in the charge / discharge abnormality processing step S4 is performed, and operations such as stop of the charge / discharge are performed. If no charge / discharge abnormality is detected,
In the expansion detection step S5, the expansion detection step S5 is executed using two expansion detection means provided on both sides of the prismatic battery. If none of the expansion detecting means has detected expansion, or if only one has detected expansion, the operation from step S2 is performed again.

On the other hand, when both of the expansion detecting means detect expansion, a timer operation start step S6 is executed.
After a predetermined time has passed, the expansion detection step S7
Is performed, and if none of the expansion detecting means detects expansion, or if only one detects expansion, the operation from step S2 is performed again. When both of the expansion detecting means are detected, the elapsed time measurement is performed to determine whether the expansion detecting means continuously detects the expansion after a predetermined time has elapsed from the previously detected time. This is performed in step S8. If at least one of the two expansion detecting means does not detect the expansion before the predetermined time has elapsed, the expansion detecting step S7 is performed again. In the time excess detection step S8, when an excess of a predetermined time is detected, it is determined that an abnormal situation has occurred, an abnormality is displayed in the abnormality display step S9, and the corresponding battery is detected in the abnormality signal notification output step S10. The abnormality is notified to a device or the like to be used, and an interruption circuit or the like provided in the charge / discharge control means or the like is operated in the output stop step S11.

FIG. 5 is a circuit diagram for explaining an example of the control means in the battery-powered equipment of the present invention. FIG. 5 is a diagram showing an example in which some components are added to a generally used battery pack protection circuit. is there. Battery pack protection circuit 30
Has a charge / discharge protection integrated circuit 31 that performs charge / discharge protection and the like, and controls charge / discharge control switching elements 32 and 33 composed of MOSEFT or the like to control charge / discharge and cut off current when an abnormality occurs. It is carried out. A switch element 34 operated by pressurization is connected in series with a resistor 35 to both terminals of the battery. Switch element 3 when expanded
4 operates, the transistors 36 and 37 are turned on. As a result, the voltage applied to the charge / discharge control switching elements 32 and 33 from the charge / discharge protection integrated circuit 31 becomes the ground voltage, regardless of the battery voltage. The switching elements 32 and 33 are opened, and the circuit is shut off.

According to the battery-powered equipment of the present invention, it is possible to safely prevent an abnormal situation in which the battery expands due to a short circuit or an abnormality in the protection circuit, which may cause damage to the battery pack or the equipment equipped with the battery. Can be prevented.

[Brief description of the drawings]

FIG. 1 is a diagram for explaining an embodiment of the present invention.

FIG. 2 is an exploded perspective view illustrating another embodiment of the present invention.

FIG. 3 is a diagram illustrating an example of a control unit provided in the battery-powered device of the present invention.

FIG. 4 is a flowchart illustrating the operation of a control unit in the battery-powered device of the present invention.

FIG. 5 is a circuit diagram illustrating an example of a control unit in the battery-powered device of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Battery pack, 2 ... Positive electrode terminal, 3 ... Negative electrode terminal, 4 ... Signal connection terminal, 5 ... Display means, 6 ... Square battery, 7 ... Holding member, 8, 8a, 8b ... Expansion detection means, 9 ... Circuit board,
DESCRIPTION OF SYMBOLS 10 ... wall surface, 11 ... virtual line, 12 ... lower case, 13 ... upper case, 14 ... expansion detection means interface, 15
a, 15b: switch, 16: central control means, 17: determination means, 18: display unit, 19: interface, 20
... Charge / discharge control means, 21 ... External connection circuit, 30 ... Battery pack protection circuit, 31 ... Charge / discharge protection integrated circuit, 32, 33
... Charge / discharge control switching element, 34 switch element, 35 resistance, 36, 37 transistor, S1 start step, S2 charge / discharge control step, S3 charge / discharge detection step, S4 charge / discharge abnormality processing step, S5 ...
Expansion detection step, S6 ... Timer operation start step, S
7 ... expansion detection step, S8 ... time excess detection step,
S9: Abnormal display step, S10: Abnormal signal notification output step, S11: Output stop step

Claims (1)

[Claims] In a battery-equipped device having at least one battery mounted in a battery storage space, an outer surface of a battery exterior body is
A battery-equipped device provided with expansion detection means for generating an expansion detection signal when the battery expands beyond a predetermined size.