JPH08236103A - Charging terminal short circuit preventing device for battery pack - Google Patents

Abstract

PURPOSE: To provide a charging terminal short circuit preventing device for battery pack with simple structure, capable of surely cutting off short current, and hardly generating malfunction. CONSTITUTION: A mechanical switch which turns on and off connection between a secondary battery and a changing terminal 13 is arranged in the interior of a battery pack 10. A projection 23 for turning on and off the switch is extruded into a guide groove 21 arranged for inserting into and engaging with a guide projection formed in a charger. Since the projection 23 of the switch is positioned inside the guide groove 21, turning on of the projection 23 except for charging by mistake is prevented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a battery pack used in a portable device such as a mobile phone, and more particularly to a charging terminal short-circuit preventing device for the battery pack.

[0002]

2. Description of the Related Art Conventionally, some portable devices have a structure in which a battery pack is detachably mounted and an electric current is supplied by the battery pack. On the other hand, the battery pack can be charged by detachably attaching it to the charger.

By the way, due to the improvement of the technology of the secondary battery, the battery capacity of the battery pack is also improved. Therefore, if the charging and output terminals provided on the surface of the battery pack are short-circuited, the energy is large. Therefore, it is becoming dangerous.

Conventionally, there have been the following means for preventing this short circuit. A mechanical switch that turns on and off the secondary battery and the terminals is installed in the battery pack, and normally the secondary battery and the terminals are turned off to prevent a short circuit between the terminals. When this battery pack is attached to the charger, the switch is turned on to turn on between the secondary battery and the terminal.

A magnetically operated reed relay for turning on / off the secondary battery and terminals is installed in the battery pack, while a magnet is attached to a device in which the battery pack is installed, and usually between the secondary battery and terminals. Is turned off by a reed relay to prevent a short circuit between terminals, and when the battery pack is mounted on a device, the reed relay is operated to turn on between the secondary battery and the terminal.

By applying the fact that the heat generation temperature rises due to the energy due to the short-circuit current when the terminals are short-circuited, a poly switch (PTC) whose resistance value rapidly increases with temperature rise is used instead of the reed relay. And limit the short circuit current.

When the terminal is not used, the terminal is covered with an insulator so that the conductor does not come into direct contact with the terminal.

Due to the characteristics of a secondary battery such as a lithium battery, it is not preferable to attach a diode or the like to prevent a short circuit between terminals.

[0009]

According to the above means, it is possible to surely turn on / off the circuit, but since it is necessary to project the switch on / off protrusions to the outside of the battery pack, it is necessary to attach them. If the projection touches anything other than the device, malfunction may occur.

There is also a method in which the projection for turning the switch on and off is not projected to the outside of the battery pack, but the projection is provided on the side of the device to which the battery pack is mounted. Since the structure must be provided so that the protrusion is pushed into the battery pack, the structure becomes complicated.

Further, the above-mentioned means have disadvantages such as malfunction due to approach or contact of magnetic products such as magnetic necklaces, iron powder adhering, and the like, and the above-mentioned means against incomplete short circuit. There is a disadvantage that the short circuit current cannot be effectively limited by
There is the inconvenience that the mechanism for automatically covering the terminals with the insulator becomes complicated.

The present invention has been made in view of the above-mentioned points, and an object thereof is to provide a charging terminal short-circuit preventing device for a battery pack, which has a simple structure, can reliably cut off a short-circuit current, and is less likely to malfunction. To provide.

[0013]

In order to solve the above problems, the present invention provides a mechanical switch for turning on / off between a secondary battery and a charging terminal in a battery pack, and a projection for turning on / off the switch. The guide projection provided on the charger is made to project into the guide groove provided. Further, according to the present invention, a switching circuit for turning on / off the secondary battery and the charging terminal is provided inside the battery pack, and the switching circuit is provided on the surface of the battery pack when the battery pack is attached to the charger. A voltage detection terminal that comes into contact with the voltage terminal and operates the switching circuit is provided.

[0014]

Since the on / off projection of the mechanical switch is located in the guide groove, there is no possibility that this projection is accidentally turned on. When the battery pack is attached to the charger, the guide protrusion of the charger presses the protrusion in the guide groove to turn on the switch, so that there is conduction between the secondary battery and the charging terminal.
The next battery can be charged. On the other hand, when the switching circuit and the voltage detection terminal are used, no voltage is applied to the voltage detection terminal when the battery pack is not attached to the charger, so the charging terminal and the secondary battery are turned off, and even if both charging Short-circuit current does not flow even if the terminals are short-circuited. When the battery pack is attached to the charger, a predetermined voltage is applied to the voltage detection terminal, so that the secondary battery and the charging terminal are energized to charge the secondary battery.

[0015]

Embodiments of the present invention will now be described in detail with reference to the drawings. 1 is a perspective view showing a battery pack 10 and a mobile phone 50 according to a first embodiment of the present invention, FIG. 2 is a perspective view of the battery pack 10 seen from the opposite side, and FIG. 3 is a battery pack 1
It is a circuit block diagram inside 0.

As shown in FIGS. 1, 2 and 3, the battery pack 10 accommodates a secondary battery 31 (see FIG. 3) therein, and the outer surface of the battery pack 10 has the secondary battery 31 (see FIG. 3). Two charging terminals 11 and 13 for charging the secondary battery 31 are exposed, and output terminals 15 and 17 for outputting to the mobile phone 50 are exposed on the opposite surface. On the upper part of the battery pack 10, a claw 19 for detachably snapping into the mobile phone 50 is provided.

On the other hand, a guide groove 21 for inserting and engaging a guide protrusion 67 provided on the charger 60 described below is provided on the lower portion of one side surface of the battery pack 10.

In the guide groove 21, a mechanical switch 37 built in the battery pack 10 (see FIG. 3).
The projection 23 for turning on and off is projected. This protrusion 2
3 does not protrude outside the guide groove 21.

On the other hand, a protrusion 25 for turning on and off a mechanical switch 39 (see FIG. 3) incorporated in the battery pack 10 is directly projected from the second side surface 10b opposite to the battery pack 10. This projection 25 is hidden on the inside of the opposite first side surface 10a (collar portion) so that the switch 39 is not turned on by accidental contact from the outside.
Is provided at the back of the side surface 10b.

Next, as shown in FIG. 3, the secondary battery 31 in the battery pack 10 has charging terminals 11, 13 and output terminals 15,
A switching transistor (FET) 33, 35 is connected between the charging terminal 13 and the secondary battery 31 and between the output terminal 17 and the secondary battery 31, respectively.

Switches 37 and 39 are connected to the gate sides of the transistors 33 and 35, respectively.

Next, as shown in FIG. 1, the portable telephone 50 is provided with a recess 51 for detachably accommodating the battery pack 10. The battery pack 1 is provided in the recess 51.
Input terminals 53 and 55 for pressure-contacting the output terminals 15 and 17 of 0 are provided.

Next, FIG. 4 is a perspective view showing a charger 60 to which the battery pack 10 is attached. As shown in the figure, the charger 60 is provided with a recess 61 for accommodating the battery pack 10, and the side wall of the recess 61 is provided with charging terminals 11 and 13 provided on the battery pack 10. The output terminals 63 and 65 for pressure contact connection and the battery pack 10 are inserted into the guide grooves 21 and 22 provided in the battery pack 10.
Is provided at a predetermined position with guide protrusions 67, 67 (the side wall on the left side of the guide protrusion is not shown).

When the battery pack 10 is not attached to the charger 60 or the mobile phone 50, both the switches 37 and 39 are off as shown in FIG.
Both transistors 33 and 35 are off.

That is, since the secondary battery 31 and the charging terminal 13 are off, even if the charging terminals 11 and 13 are short-circuited, there is no possibility that a short-circuit current will flow. Moreover, since the secondary battery 31 and the output terminal 17 are also off, the short-circuit current does not flow between the output terminals 15 and 17.

Particularly in the case of the present invention, since the on / off projection 23 of the switch 37 is located in the guide groove 21,
There is no fear that the protrusion 23 will be turned on by mistake, and the malfunction can be reliably prevented.

Next, when the battery pack 10 is mounted in the recess 61 of the charger 60 (either in the state where the battery pack 10 is alone or in the state where the battery pack 10 is attached to the mobile phone 50), the battery pack 10 is charged. The output terminals 63 and 65 of the charger 60 are pressure-connected to the terminals 11 and 13. At the same time, the guide protrusion 67 presses the protrusion 23 in the guide groove 21 to turn on the switch 37.

As a result, the transistor 33 is turned on, the charging terminals 11 and 13 become live parts, and the secondary battery 31 is activated.
Can be charged to.

On the other hand, the battery pack 10 is used as a portable telephone 50.
When the battery pack 10 is mounted in the recess 51, the output terminals 15 and 17 of the battery pack 10 become the input terminals 53 and 55 of the mobile phone 50.
Is pressure connected. At the same time, a portion a on the inner wall surface of the recess 51
(See FIG. 1), the protrusion 25 of the battery pack 10 abuts,
The switch 39 is turned on.

As a result, the transistor 35 is turned on, the output terminals 15 and 17 become live parts, and the portable telephone 5
0 can be supplied with electric power. In addition, the protrusion 25 is the battery pack 1.
The switch 39 is turned on only when 0 is attached to the mobile phone 50, so that the switch 39 is turned on at the opposite second side surface 10b.
Since it is provided in the above, the malfunction can be surely prevented.

Next, FIG. 5 is a perspective view of a battery pack 10 'according to a second embodiment of the present invention. FIG. 6 is a circuit diagram of the inside of the battery pack 10 '. The same parts as those in the above-mentioned embodiment are designated by the same reference numerals and detailed description thereof will be omitted.

This battery pack 10 'differs from the battery pack 10 in that the secondary battery 31 and the charging terminal 13 are different from each other.
Instead of using a mechanical switch 37 to turn on and off the switch, a switching circuit 41 is provided to turn it on and off. The switching circuit 41 is provided with a voltage detection terminal 43 for controlling ON / OFF of the transistor 33.

As shown in FIG. 5, the voltage detecting terminal 43 is provided so as to be exposed between the two charging terminals 11 and 13. A charger (not shown) to which the battery pack 10 'is attached is provided with a voltage terminal for supplying a predetermined voltage to the voltage detection terminal 43 in addition to an output terminal for energizing the charging terminals 11, 13. ing.

Also in the case of this battery pack 10 ', as shown in FIG. 6, when the battery pack 10' is not attached to the charger, no voltage is applied to the voltage detection terminal 43, so that the gate of the transistor 33 is not applied. However, since no voltage is applied to the charging terminals 11, the charging terminals are turned off, and even if the charging terminals 11 and 13 are short-circuited, no short-circuit current flows.

When the battery pack 10 'is attached to the charger, the output terminals of the charger are pressure-connected to the charging terminals 11 and 13 of the battery pack 10', and at the same time, the voltage terminal is also connected to the voltage detecting terminal 43. A predetermined voltage is applied by pressure contact connection, and thus a predetermined voltage is applied to the gate of the transistor 33 by the switching circuit 41 to turn it on,
Therefore, the charging terminals 11 and 13 serve as live parts and the secondary battery 3
1 is charged.

Needless to say, the battery pack according to the present invention can be used in various mobile devices other than mobile phones.

[0037]

As described in detail above, the present invention has the following excellent effects. Since the protrusion for turning on and off the mechanical switch is projected into the guide groove originally provided in the battery pack, there is no risk that this protrusion will be accidentally turned on except when charging, and the malfunction is reliably prevented. Not only can it be made safe and reliable, but its structure can be simplified.

When the battery pack is provided with the switching circuit and the voltage detection terminal for operating the switching circuit, the electric circuit can prevent the charging terminal from being short-circuited, so that the space inside the battery pack is larger than that of the mechanical switch. As a result, the battery pack can be downsized and the degree of freedom in design can be improved.

When a mechanical switch for turning on / off the current between the secondary battery and the output terminal of the battery pack is provided,
A short circuit between output terminals can be reliably prevented.

[Brief description of drawings]

FIG. 1 is a perspective view showing a battery pack 10 and a mobile phone 50 according to a first embodiment of the present invention.

FIG. 2 is a perspective view of the battery pack 10 seen from the opposite side.

FIG. 3 is a circuit configuration diagram inside the battery pack 10.

FIG. 4 is a perspective view showing a charger 60 to which the battery pack 10 is attached.

FIG. 5 is a battery pack 10 ′ according to a second embodiment of the present invention.
It is a perspective view of.

FIG. 6 is a circuit configuration diagram inside a battery pack 10 '.

[Explanation of symbols]

 10,10 'Battery pack 11,13 Charging terminal 15,17 Output terminal 21,22 Guide groove 23 Protrusion 25 Protrusion 31 Secondary battery 37,39 Mechanical switch 41 Switching circuit 43 Voltage detection terminal 50 Mobile phone (portable device) 60 charger 67 guide protrusion

Claims (3)

[Claims] 1. A secondary battery is housed inside, and a charging terminal for charging the secondary battery and an output terminal for outputting from the secondary battery are provided on the surface thereof, and a portable device and a charger are provided. Each of them has a structure that can be detachably attached, and a guide groove for inserting and engaging the guide protrusion provided on the charger is provided on the outer surface of the charger. In the battery pack, the battery is supplied to the secondary battery through the charging terminal, and the current from the secondary battery is supplied to the portable device through the output terminal when the battery is attached to the portable device. Between a charging terminal and a charging terminal, a mechanical switch for turning on / off the charging current is provided, and a projection for turning on / off the switch is made to project into the guide groove. Apparatus. 2. A secondary battery is housed inside, and a charging terminal for charging the secondary battery and an output terminal for output from the secondary battery are provided on the surface thereof, and a portable device and a charger are provided. Each of them has a structure that can be detachably attached to the rechargeable battery. When the rechargeable battery is attached to the charger, the rechargeable battery supplies a charging current to the rechargeable battery through the charging terminal. In a battery pack that supplies a current to a portable device through the output terminal, a switching circuit that turns on / off the charging current between the secondary battery and a charging terminal is provided inside the battery pack, and the surface of the battery pack is provided. A charging terminal for a battery pack, which is provided with a voltage detection terminal for operating the switching circuit by contacting a voltage terminal provided on the charger when the battery pack is mounted on the charger. Fault prevention device. 3. A mechanical switch for turning on / off a current from the secondary battery is provided between the secondary battery and an output terminal inside the battery pack, and the battery pack is carried on the surface of the battery pack. The charging terminal short-circuit preventing device for a battery pack according to claim 1 or 2, wherein a projection for turning on and off the switch is projected at a position where the switch comes into contact with the portable device when mounted on the device.