JPH01219270A - Electronic lock - Google Patents

Abstract

PURPOSE:To automatically make unlocked state when a battery is used up by method in which an urgent holding type electromagnet to operate locker in preference to the usual holding type electromagnet and a sensor to watch the consumption of battery are provided, and when the consumption of battery is increased unlocking state is produced automatically. CONSTITUTION:An electronic lock is provided with a bolt 1, an unusually using magnetic holding type electromagnet 4, a permanent magnet 5, a movable iron piece 7 for unlocking, a sensor 11 to detect the position of the piece 7, an usually using magnetic holding type electromagnet 12, CPU 17, and a sensor 18 for the voltage of battery. When a battery 19 is consumed, the drop of voltage is detected by the sensor 18, and electric current is sent to the magnet 4 through a switch circuit 20 by CPU 17 to weaken the holding force of the magnet 5. When the force of the spring 6 is increased, the piece 7 is clockwise turned and a hook 8 is released to make unlocked state. During the period when the battery is consumed, unlocking is automatically made to avoid becoming the opening of door impossible.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field of Industrial Application The present invention relates to an electronic lock that locks and unlocks using electrical signals.

(0) Prior Art Conventional electronic locks lock and unlock using actuators such as electromagnets that move in response to electrical signals.

(c) Problems to be Solved by the Invention The above-mentioned electronic locks, especially battery-powered electronic locks, have the disadvantage that they cannot be unlocked when the battery is exhausted in a locked state.

In order to eliminate this inconvenience, conventional methods have been to issue an alarm immediately before the battery runs out. However, this method was not effective in the case of electronic locks that were not used for a long time. In particular, in applications such as safe locks, if the battery dies while the lock is still locked, the door cannot be opened unless the lock itself is destroyed or the door is destroyed.

(d) Means for solving the problem In order to eliminate the above-mentioned inconvenience, the lock is automatically turned into an unlocked state when the battery is exhausted. To do this, it uses a sensor that detects when the battery is depleted, and an associated holding electromagnet that operates using the little energy left in the battery or an emergency condenser.

(iv) Function When the battery is exhausted or when the power supply is lost due to a failure in the battery circuit, the sensor detects this and automatically sets the lock to the unlocked state, thus all of the above-mentioned problems are solved.

(f) Example The present invention will be explained below with reference to the drawings.

FIG. 1 is a simplified diagram showing the structure of an embodiment of the electronic lock of the present invention.

Figure 1 shows the locked state. 1 is the bolt, 2 is the outer casing of the lock, 3 is the strike, 4 is the magnetic retention electromagnet for use in case of an abnormality, 5 is the permanent magnet, 6 is the spring, and 7 is the battery consumption. 8 is a hook that locks the bolt l; 9 is a bottle that supports the hook 8; lO is a spring that pushes down the hook 8 and locks the bolt 1; 11 is a movable iron piece that locks the bolt 1; Sensor that senses position, 1
2 is a magnetic holding electromagnet for normal use for normal locking and unlocking, 13 is a permanent magnet, 14 is a movable iron piece that pushes down the hook 8 to unlock it, and 15 is a movable iron piece that urges the movable iron piece 14 clockwise. 16 is a handle attached to the bolt l, 17 is a CPU that decodes the key code and issues commands to move the electromagnets 4 and 12, such as a Mitsubishi M50.
940.18 is the battery voltage sensor, 19 is the battery, 20
is a switch circuit that sends current of specified polarity to the electromagnets 4 and 12 according to instructions from the CPU.

In Fig. 2, the electromagnet 4 is in the open state, and the force of the spring 6 causes the movable iron piece 7 to push down the hook 8 and move it counterclockwise, changing the state from the locked state shown in Fig. 1 to the unlocked state. Indicates the condition.

FIG. 3 shows an embodiment in which a capacitor is used to open the electromagnet 4 even in the event of a sudden failure of the battery.

In FIG. 3, 21 is a capacitor and 22 is a diode.

The movable iron piece 7 of the electromagnet 4 in FIG. 1 is held in a retained state by a permanent magnet 6. In this state, the tip of the movable iron piece 7 is separated from the hook 8, and the hook 8 is connected to the spring 10.
The hook 8 is in a locked state as it is being rotated clockwise by the force .

Normal locking and unlocking operations are performed by the electromagnet 12 as follows.

A key code is input into the CPU 17 using a well-known card reader or numeric keypad, and when it is determined to be correct, the CPU 17 sends a current to the electromagnet 12 through the switch circuit 20 to release the hold. When the holding force of the permanent magnet 13 weakens due to the current and the force of the spring 15 becomes stronger, the movable iron piece 14 rotates clockwise. The force of the spring 15 is selected to overcome the force of the spring IO and rotate the hook 8 counterclockwise, but the movable iron piece 14 rotates the hook 8 counterclockwise to the unlocked state. To lock, press C
In the case of P U 17, through the switch circuit 20,
A current is sent to the electromagnet 12 so as to absorb the movable iron piece 14. Then, the movable iron piece 14 rotates counterclockwise and is again attracted by the force of the permanent magnet, returning to the holding state. The hook 8 is then released from the force of the spring 150, and the hook 8 is released from the force of the spring 1.
It rotates clockwise with zero force and returns to the locked state.

Next, what happens when the battery 19 is exhausted will be explained with reference to FIG.

Battery depletion is sensed by a sensor 18. Generally, the sensor 18 monitors the battery voltage, and the battery cycle is determined from the voltage drop. A battery depletion signal from the sensor 18 is sent to the CPU 17. Then CPU 1? A current is sent to the electromagnet 4 through the switch circuit 20 in a direction that reduces the magnetic flux of the permanent magnet 4. The holding force of the permanent magnet 5 weakens due to the current, and the force of the spring 60 that attempts to release the permanent magnet 5 becomes stronger, causing the movable iron piece 7 to rotate clockwise. Since the force of the spring 60 is selected to overcome the force of the spring IO and rotate the hook 8 counterclockwise, the movable iron piece 7 rotates the hook 8 counterclockwise to the unlocked state.

In this state, the hook 8 remains unlocked and the electromagnet 12
In either the open or held state, the unlocked state is maintained in a blind relationship.

FIG. 2 shows this unlocked state. That is! Regardless of whether the magnet 12 is in a normal locked state or an unlocked state, the opening operation of the electromagnet 4 brings it into the unlocked state. In this state, a normal locked state cannot be realized.

That is, the function of the electromagnet 4 has priority over that of the electromagnet.

In the second state, the user opens the door and replaces the battery, which is normally done from inside the door. Then sensor 1
CP detects both that the battery is normal from 8 and that the movable iron piece 7 is in the open position from sensor 11.
U 17 sends a current to electromagnet 4 through switch circuit 20 in the direction of attracting movable iron piece 7 . The current causes the movable iron piece 7 to rotate clockwise and is held in place by the force of the permanent magnet 50.

This state continues until the end of the next battery life.

In this state, the hook 8 is again free from the influence of the movable iron piece 7 and can move according to the operation of the electromagnet 12, so that the above-mentioned normal locking and unlocking operations are performed and the lock operates as a normal electronic lock.

In the above explanation, when the battery voltage approaches the end of the battery life, the electromagnet 4 is opened using the small amount of remaining battery energy to become unlocked. The above operation cannot be performed if the lock is turned off, or if a wired electronic lock is supplied with electric current from the outside and the current is suddenly cut off due to a disconnection or short circuit.

For such a case, the embodiment of FIG. 3 is shown.

In FIG. 3, current is constantly supplied from the battery to the capacitor 21 through a directional element such as a diode 22.
is charged to a voltage close to the battery voltage. If the battery suddenly fails and the sensor 18 detects it, the C
The P U 17 sends the electric charge of the capacitor 21 to the electromagnet 4 through the switch circuit 20 to open the electromagnet 4 and unlock it. The same applies to a case where current is supplied from outside through an electric wire instead of the battery 19, and the current is cut off due to wire breakage or short circuit. In this case, the diodes 22 must be inserted at the three locations shown to prevent the charge in the capacitor from escaping through a faulty battery or external circuit. CPU17
Both the power supplied to the electromagnet and the power supplied to the electromagnet are supplied from the capacitor 21. The required supply time is between a few milliseconds and tens of milliseconds.

An electrolytic capacitor, an electric double layer capacitor, or the like is used as the electricity storage device 21.

(g) Effects of the invention Generally, for security reasons, batteries in electronic locks must be replaced from inside the door when the door is opened, but the electronic lock of the present invention automatically unlocks when the battery is exhausted and can be opened. Since the door can be opened, even when used in an electronic lock such as a safe, there will be no inconvenience such as being unable to open the door when the battery is exhausted.

If you want to be able to open the WI door even if the power supplied from the outside is cut off, you can easily do so with the present invention.

[Brief explanation of the drawing]

FIG. 1 is a simplified structural diagram showing an embodiment of the present invention, FIG. 2 is a diagram showing this unlocked state, and FIG. 3 is a simplified structural diagram showing another embodiment of the present invention. 1...Bolt, 4...Holding electromagnet for abnormal situations, 8...Hook, 12...Holding electromagnet for normal times, 17... ...C20,18...
...Sensor, 20...Switch circuit. 1st country l...Bolt 4...Holding electromagnet for use in case of an abnormality 8...-Hook 1
2...Normal holding type electromagnet 17...
C2018...--Sensor 20...Switch circuit

Claims (1)

[Claims] (1) In an electronic lock having a bolt, a means for locking the bolt, and a holding type electromagnet for normal use that drives the locking means, when the locking means is driven with priority over the electromagnet for normal use, an abnormality occurs. A holding type electromagnet, a sensor for monitoring battery consumption or current interruption, and a switch circuit for supplying current to the electromagnet, and when the sensor detects battery consumption or current interruption, current is supplied through the switch circuit. An electronic lock characterized in that the electronic lock is turned into an unlocked state by supplying a voltage and driving a locking means.