JP2654106B2 - Battery pack - Google Patents

Description

The present invention relates to a battery pack containing a secondary battery used for a rechargeable power tool, a rechargeable VTR camera and the like.

[Prior art] At present, the charging time of a battery pack incorporating a secondary battery such as a Ni-Cd battery is being shortened, and in response to the shortening of the charging time, charging for one hour (1C) → 30 minutes charge (2C) → 15 minutes charge (4C)
Therefore, safety measures are required. In other words, since charging is normally controlled by the charge control circuit, charging is stopped by detecting that the secondary battery is fully charged. However, if the charge control circuit breaks down, no control is performed, and charging is not stopped. Will be.

At this time, if the charging time is relatively long, the charging current is small, so that even if the charging is not stopped, the rechargeable battery only needs to be deteriorated. However, the charging is stopped with a large current in the case of short charging. If not, the temperature of the secondary battery rises abnormally, which may eventually lead to an explosion, causing harm to the human body or a fire.

[Problem to be Solved by the Invention] Therefore, the present inventors put a thermo switch that operates when the temperature of the secondary battery becomes high in the charging path in the battery pack,
We proposed to take safety measures in the case of no control.However, it is possible to charge a battery pack that has safety measures in such a short time charging with a charger for a long time charging and to provide a safe driven device. It is also desired to be able to drive.

The present invention has been made in view of the above points, and has as its object the provision of a thermoswitch for safety measures during short-time charging, and a charger for short-time charging as well as for long-time charging. It is an object of the present invention to provide a battery pack that can be charged by a charger of the present invention and that can safely drive a driven device.

[Means for Solving the Problems] The present invention relates to a battery pack that accommodates a secondary battery in a case, is charged by a charger, is detachably attached to a driven device, and supplies power to a load. A pair of charging / discharging connection terminals connected to both ends of the secondary battery, a charging connection terminal in which a thermoswitch for overheating protection is inserted in series, and the temperature of the secondary battery detected for charge control At least a connection terminal for signal output of the temperature sensor to be provided, and these connection terminals are selected according to different types of chargers so as to be connectable to different types of chargers.

[Operation] In the case of charging using a short-time charging charger, a thermoswitch for overheating protection is inserted in series so as to cope with an abnormal temperature rise of charging in which a failure occurs in the charging control circuit. The charging connection terminal is connected to the charging output of the short-time charging charger to perform charging, and the charging control is performed by outputting the detection output of the temperature sensor to the short-time charging charger and provided on the charger side. This is performed by charging control means.

When charging is performed using a normal long-time charging charger, charging is performed using a charging / discharging connection terminal to which a thermoswitch for overheating protection is not inserted and connected.

In addition, connect the discharge connection terminal to which the thermoswitch is not inserted and connected at the time of discharge to the load, and prevent the occurrence of an accident due to the stoppage of the load due to the opening and closing of the thermoswitch caused by the rise of the battery temperature when driving the load and the sudden restart of the operation. .

EXAMPLES The present invention will be described below with reference to examples.

FIG. 1 shows the whole battery pack 1 of one embodiment, and a secondary battery such as a Ni-Cd battery is built in a case 1a of the battery pack 1 as shown in FIG. 2 or FIG. In addition, a temperature sensor 3 for performing charge control and a thermoswitch 4 for safety measures at the time of short-time charging are built in, and the battery of the charger 5 as shown in FIGS. Each side of the front end of the columnar mounting portion 1a for insertion into the pack connecting portion 6 or mounting to the battery pack storage portion 8 of the driven device 7 such as an electric drill shown in FIG. Vessel 5,
Connection terminals for electrically connecting to the driven device 7 9 ₁ to 9 ₄
Is exposed.

The connection terminals 9 _1, 9 ₃ connection terminal charge and discharge, the connection terminals 9 ₂ connecting charging terminal, also the connection terminals 9 ₄ respectively constituting the connection terminal of the signal output of the temperature sensor 3.

The electric circuit in the case 1a of the battery pack 1 is configured as shown in FIG. 2 or FIG. That both ends of the secondary battery 2 is connected via a thermoswitch 4 between the connection terminals 9 ₁ and 9 _2, also the resistor R ₁ between the connection terminals 9 ₃ and 9 _4, diode D _1, D be connected to one temperature sensor 3 consisting of _2, also it is the negative terminal of the negative terminal and the secondary battery 2 temperature sensor 3 are connected in common.

The charger 5 shown in FIG. 2 constitutes a charger for short-time charging, and operates using a rectifier circuit 10 for rectifying and smoothing an AC power supply AC and a DC obtained by rectifying and smoothing the AC power supply as a power supply. a switching circuit 11 to a switching element 12 driven by the oscillation output of the switching circuit 11 performs power conversion by passing a high frequency switching current to the primary winding N ₁ in switching of the switching element 12, the secondary A switching regulator comprising a transformer 13 for transmitting power to the battery pack 1 is provided as a power source for a charging control circuit 14 and a temperature conversion circuit 15 to be described later.
A temperature conversion circuit 15 for taking in the voltage between both ends of the temperature sensor 3 provided for detecting the temperature of the secondary battery 2 and converting the voltage as a temperature signal; When the temperature rise rate is reached, it is determined that the charging is completed, the oscillation of the switching circuit 11 is stopped, or the charging current is detected by a current detecting element such as a current transformer (not shown).
Detected and the charging current based on the current detection signal and a charging control circuit 14 for controlling the switching circuit 11 so that a constant current by the output of the secondary winding N ₂₁ diode D ₃ of the transformer 13 , D ₄ , rectified and smoothed by the choke coil L, the rectified and smoothed current is used as the charging current of the secondary battery 2, and the output of the secondary winding N ₂₂ is rectified and smoothed by the diode D ₅ and the capacitor C _1. The obtained DC is supplied to the charge control circuit 14 and the temperature conversion circuit 15 as power. Charge control circuit
The reference numeral 14 indicates that the output charge control signal is sent to the switching circuit 11 via the photocoupler 16.

The battery pack 2 is connected to the charger 5 configured as described above.
Connection terminals to the connection terminals 17 ₁ to 17 ₄ of the charger 5 side, the corresponding
9 _{by 1-9 4} connected, is detachably connected, the secondary battery 2 is connected through the thermoswitch 4 for overtemperature protection for charging output, the signal input end of the temperature conversion circuit 15 Is connected to both ends of the temperature sensor 3.

Thus, in normal times, the connection terminal 17 ₁ of the charger 5 →
A short time charging by supplying a large current to the secondary battery 2 in circuit between the connection terminal 17 and _second connection terminal 9 ₁ → 2 battery 2 → thermoswitch 4 → connection terminal 9 ₂ → charger 5 battery pack 1 .

When the temperature rise rate in the case 1a of the battery pack 1 increases near the completion of charging and becomes equal to or more than a predetermined value, the charging control circuit 14 determines that charging is completed and sends a charging control signal to the switching circuit 11 through the photocoupler 16. To stop charging.

Here the ground 18 'thermoswitch 4 inside the case 1a of the battery pack 1 of the charge control circuit 14 and the temperature conversion circuit 15 in the case 1a of the battery pack 1, the connection terminals 9 _2, 9 ₃ and the charger 5 side connection Ground 1 of charging output system via terminals 17 ₃ and 17 ₂
Connected to 8.

By the way, when charging control cannot be performed and the temperature of the secondary battery 2 in the case 1a of the battery pack 1 rises abnormally, the thermoswitch 4 is opened to cut off the charging current. Then the resistance
Grounds 18 and 18 'are connected only within the charger 5 via Ra. The charging with a small current charging current limited by the resistor Ra via a connection terminal 17 _3, 9 ₃ flows in the secondary battery 2 is continued.

3 is a charger for charging for a long time, for example, one hour, and rectifies an AC stepped down by a step-down transformer 19 with a rectifier circuit 10 as shown in FIG. the secondary battery 2 in the battery pack 1 side is adapted to supply a charging current, the output of the rectifier circuit 10 is connected to the connection terminals 21 _1, 21 ₂ via the thyristor 20.

Connecting terminals 21 ₁ corresponds to the connection terminal 9 ₁ of the battery pack 1,
Connecting terminal 21 ₂ corresponds to the connection terminal 9 _3, the charging current flowing through the secondary battery 2 without through the thermoswitch 4 in the battery pack 1.

The connecting terminal 21 ₂ corresponds to the ground of the temperature sensor 3 within the case 1a of the battery pack 1, constituting the signal input end of the temperature control circuit 23 together with the connection terminals 21 ₃ to be connected to the connection terminal 9 ₄ of the battery pack 1 I do.

Charge control is performed by the timer control circuit 22 and the temperature control circuit 23, the start of the timer control circuit 22 from the start of charging operation, the thyristor 20 by driving the transistor Q ₁ when the time is up after the lapse e.g. 1 hour OFF either by, or when the detected temperature increase rate of the temperature sensor 3 exceeds a specific, cell open reset circuit temperature control circuit 23 controls the charging by either turning off the thyristor 20 by driving the transistor Q ₂ 24 detects that the battery pack 1 is removed by the voltage between the connecting terminals 21 _1, 21 _2, forcibly resetting the timer control circuit 22 at its detection output, has a function to turn off the thyristor 20 at the same time Things. Note emitting diode LED, the transistor Q ₃ are constituting the charging display circuit. The power supply circuit 25 is a power supply circuit for the timer control circuit 22 and the battery open reset circuit 24.

When connecting the battery pack 1 of the present invention to an electric tool such as an electric drill or an electric saw as shown in FIG.
Connect to a load such as a motor at 9 ₁ and 9 ₃ and discharge from the secondary battery 2 to the load. Here not perform power supply to the load via the connection terminals 9 ₂ connected thermo switch 4, thermoswitch 4 load stops away opened by an increase in battery temperature due to use, after which the secondary battery 2 When the thermoswitch 4 returns to cool and the driven equipment suddenly operates,
This is because power tools, particularly power saws, are very dangerous.

[Effect of the Invention] The present invention relates to a battery pack configured as described above,
A pair of charging / discharging connection terminals connected to both ends of the secondary battery, a charging connection terminal in which a thermoswitch for overheating protection is inserted in series, and a temperature of the secondary battery for charge control. Since at least a connection terminal for a signal of a temperature sensor to be detected is provided, and these connection terminals are selected according to different types of chargers and can be connected to different types of chargers, a short-time charging charger can be used for a long time. It can also be connected to a charger for charging, especially when charging for a short time, charging through a thermo switch for overheating protection prevents the explosion and fire from occurring when the temperature rises abnormally. .

[Brief description of the drawings]

FIG. 1 is a perspective view of an embodiment of the present invention, FIG. 2 is a circuit configuration diagram when the above is connected to a charger for short-time charging, and FIG. 3 is a circuit configuration when connected to a normal charger. Fig. 4, Fig. 4 is a perspective view of the battery charger mounted on the battery charger, Fig. 5 is a side view of the battery charger mounted on the battery charger, and Fig. 6 is a power drill mounted on the battery charger. FIG. 1 battery pack, 1a case, 2 a secondary battery, the temperature sensor 3, the thermo-switch 4, 5 charger, 9 ₁ to 9 ₄ is a connection terminal.

Claims (1)

(57) [Claims] 1. A battery pack containing a secondary battery in a case, charged by a charger, detachably mounted on a driven device and supplying power to a load, connected to both ends of the secondary battery. A pair of connection terminals for charging and discharging, a connection terminal for charging in which a thermoswitch for overheating protection is inserted in series, and a signal output of a temperature sensor for detecting the temperature of the secondary battery for charge control. A battery pack characterized in that at least the following connection terminals are provided, and these connection terminals are selected according to different types of chargers so as to be connectable to different types of chargers.