JPH0584351B2 - - Google Patents

Description

TECHNICAL FIELD The present invention relates to a keyless entry device, and more particularly to an improvement in a keyless entry device that automatically locks and unlocks a door by receiving a code signal using weak radio waves from a transmitter. It is.

BACKGROUND ART This type of keyless entry device can automatically lock and unlock a door without using a key by receiving a code signal using weak radio waves from a transmitter. By the way, when locking and unlocking the door by receiving a code signal using weak radio waves, it is necessary to reliably lock and unlock the door when the code signal is received. However, there is no way to determine whether the received code signal actually unlocks the door or is due to an erroneous operation, and therefore, even if a code signal is received due to an erroneous operation, the door will naturally become unlocked. Therefore, there is an inconvenience that the locked state may be released even when the user does not intend to do so. for example,
As previously proposed by the applicant, if a system is adopted in which the locked and unlocked states are alternately reversed each time the transmission switch of the transmitter is pressed, it is possible to unintentionally press the transmission switch and enter the locked state. Even if you think so, the vehicle is actually unlocked, and there is a risk that you may leave the vehicle without noticing this.

OBJECT OF THE INVENTION The present invention has been made in view of the above-mentioned conventional problems, and its purpose is to detect when the lock is switched to the unlocked state by a code signal or by the operation of a key or lock knob. By automatically returning to the locked state after a certain period of time and completely eliminating the influence of code signals from outside the predetermined identification area and code signals from other vehicles, it prevents inadvertent door unlocking due to erroneous operation. An object of the present invention is to provide a keyless entry device for a vehicle that can completely prevent theft.

Configuration of the Invention In order to achieve the above object, the present invention is configured as follows.

That is, the vehicle keyless entry device according to the present invention includes () a receiving means for receiving a code signal using weak radio waves from a portable transmitter;
an electric field strength determining means for determining the electric field strength of the code signal received by the receiving means; () a code determining means for determining whether the code signal received by the receiving means matches an identification code unique to the vehicle; () a locking mechanism that locks and unlocks the door; () as a result of the determination by the electric field strength determination means, the electric field strength of the received code signal is equal to or higher than a predetermined level, and as a result of the determination by the code determination means, the received code A lock mechanism control means that controls the operation of the lock mechanism when the signal and the identification code match; () a timer that starts a timing operation when the unlock detection means detects the unlocked state of the lock mechanism and times up after a predetermined period of time; () when the timer times out; The present invention is characterized by comprising lock instruction means for instructing the lock mechanism control means to lock the lock mechanism.

Embodiments of the Invention Hereinafter, preferred embodiments of the present invention will be described based on the drawings.

FIG. 1 is an explanatory diagram showing an identifiable area, and FIG. 2 is a block diagram showing an embodiment of the present invention.

In the figure, 10 is a portable transmitter, and by pressing a transmitting switch 12, a vehicle-specific code signal is transmitted as a weak radio wave by FM, PCM modulation, etc.

Reference numeral 14 denotes a keyless entry device mounted on the vehicle 15, which includes a receiver 16, a discrimination circuit 18, a solenoid 20, a door lock mechanism 22, a key lock mechanism 24, and the like.

The receiver 16 receives the weak radio waves transmitted from the transmitter 10, amplifies and demodulates them, and reproduces a code signal.

The determination circuit 18 is configured with, for example, a microprocessor, and determines whether the level electric field strength of the received code signal output from the receiver 16 is equal to or higher than a predetermined level, so that the transmitter 10 receives a predetermined signal from the receiver 16. It is determined whether or not the code signal is within the identification area 26 surrounded by a circle with radius d, and it is also determined whether the code signal matches a vehicle-specific code signal, and the radio wave is transmitted from within the identification area 26. The unlock control signal CS is sent out only when the code signal matches the vehicle-specific code signal. Further, the discrimination circuit 18 is supplied with a parking signal PS from the parking brake 28 indicating that parking is in progress, and is configured to accept the code signal from the receiver 16 only when the parking signal PS is on. There is. Further, a timer circuit 30 is connected to the discrimination circuit 18, and this timer circuit 30 starts measuring time from the time when the unlock control signal CS is sent.
When the timer circuit 30 times up after a predetermined period of time has elapsed, the discrimination circuit 18 sends out a lock signal RS in place of the unlock control signal CS.

The solenoid 20 is energized in opposite directions by the unlock signal CS and the lock signal RS from the discrimination circuit 18.

Door lock mechanism 22 unlocks or locks the door depending on the energization state of solenoid 20. The door lock mechanism 22 also unlocks and locks the door by means of a key lock mechanism 24 based on key operations. In this case, when the door lock mechanism 22 is unlocked by the key lock mechanism 24, the actuator (not shown) of the solenoid 20 is moved. It is detected by a change or the generation of a back electromotive force, and this detection signal DS is supplied to the discrimination circuit 18,
Based on this, the timer circuit 30 is activated and starts counting time, and when the timer circuit 30 times up after a predetermined period of time has elapsed, a door lock signal is sent from the discrimination circuit 18.
RS is supplied to the solenoid 20, and in response, the door lock mechanism 22 is actuated to lock the door. In addition to the above-described means, known means such as a micro switch operated by movement of a link constituting the door lock mechanism may be employed as a means for detecting the unlocked state.

Next, the operation will be explained. When the vehicle stops and the parking brake 28 is activated, the parking signal PS is activated.
is on and the door lock mechanism 22 is in the locked state. When the transmission switch 12 of the transmitter 10 is pressed in this state to transmit a weak radio wave representing a code signal, the code received by the receiver 16 is first transmitted. Discrimination circuit 18 according to the electric field strength of the signal
It is determined whether or not it is from within the identification area 26. If the determination result is outside the identification area 26, the unlock control signal CS is not output from the determination circuit 18 even if the received code signal matches the vehicle-specific code signal, and therefore the solenoid 20 is disabled. In the energized state, the door lock mechanism 2
2 keeps the door locked. Further, if the determination result of the determination circuit 18 is within the identification area 26, it is then determined whether the received code signal matches the vehicle-specific code signal, and when the two match, the determination circuit 18 performs unlock control. A signal CS is output, which energizes the solenoid 20 and operates the door lock mechanism 22 to unlock the door. This makes it possible to open the door. At the same time, the timer circuit 30 starts counting time, and after a predetermined time period sufficient to open the door from inside the identification area 26 has elapsed, the timer circuit 30 times out. Based on the time-up of the timer circuit 30, the discrimination circuit 18 is activated and the door lock control signal RS is outputted. This door lock control signal RS energizes the solenoid 20 in the opposite manner to that described above, thereby returning the door lock mechanism 22 to the door lock state. Therefore, the door cannot be opened from now on until the code signal from the transmitter 10 is received again.

Furthermore, instead of transmitting a code signal from the transmitter 10, the door can be opened by inserting a key into the key lock mechanism 24 and placing the door lock mechanism 22 in an unlocked state. In this state, as the actuator of the solenoid 20 moves, the detection signal DS is supplied from the solenoid 20 to the discrimination circuit 18, and at the same time, the timer circuit 3
0 starts timing, and when it times up,
A door lock signal RS is output from the discrimination circuit 18,
Based on this, the solenoid 20 is energized, the door lock mechanism 22 is activated, and the door is returned to the locked state.

Furthermore, while the vehicle is running, the parking brake 2
8 is inactive, the parking signal PS
is off, so the discrimination circuit 18 determines that the receiver 1
It does not accept the code signal from 6 and prohibits the door lock mechanism 22 from entering the unlocked state.
Note that means for detecting when the vehicle is running include a vehicle speed sensor that detects the running speed of the vehicle, a wheel speed sensor that detects the rotation of the wheels, an ignition signal of the engine,
Alternatively, known means can be employed, such as using a detection sensor that detects insertion of the ignition key into the key cylinder.

Effects of the Invention As described above, according to the present invention, the door lock mechanism is operated by the lock mechanism control means (discrimination circuit 18 in the above example) or manual key operation (key lock mechanism 24), and the door is opened. When the door is in the unlocked state, the timer times up after a predetermined period of time has elapsed from that point, and the door lock mechanism is activated by the door lock instruction means (discrimination circuit 18) to return the door to the locked state. Even if a code signal is sent from the transmitter due to an erroneous operation within the identification area, the door will become unlocked for a while, but the door will automatically return to the locked state after a predetermined period of time has passed.
It is possible to prevent forgetting to lock the door, and it is possible to prevent theft. Furthermore, even if the door is unlocked while the vehicle is running, it automatically returns to the locked state after a predetermined period of time has elapsed, thereby providing an excellent effect of ensuring safety while driving.

Furthermore, in the present invention, the lock timing is controlled by the timer's timing operation regardless of the transmission from the transmitter, so there is no need to keep the transmitter on all the time, and consumption of the transmitter's battery can be reduced. can.

Furthermore, by accepting the code signal from the transmitter only within the identification area as in the above example, it is possible to prevent the door from being inadvertently unlocked and to prevent the influence of other vehicle code signals.

Furthermore, if the reception of the code signal is restricted by the parking signal from the parking brake as in the above example, there is an advantage that unnecessary unlocking of the door by the transmitter during driving can be avoided.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram showing an identifiable area according to the present invention, and FIG. 2 is a block diagram showing an embodiment of the present invention. 10... Transmitter, 14... Keyless entry device, 16... Receiver, 18... Discrimination circuit, 20...
...Solenoid, 22...Door lock mechanism, 24...
...Key lock mechanism, 26...Identification area, 28
...Parking brake, 30...Timer circuit.

Claims (1)

[Scope of Claims] 1. Receiving means for receiving a code signal using weak radio waves from a portable transmitter; Field strength determining means for determining the electric field strength of the code signal received by the receiving means; By the receiving means. code determining means for determining whether the received code signal matches an identification code unique to the vehicle; a locking mechanism for locking and unlocking the door; and as a result of the determination by the electric field strength determining means, the received code signal the electric field strength is equal to or higher than a predetermined level, and as a result of the determination by the code determination means,
a lock mechanism control means that controls the operation of the lock mechanism when the received code signal and the identification code match; and a lock mechanism control means that controls the operation of the lock mechanism when the received code signal and the identification code match; an unlock detection means for detecting the unlock state of the lock mechanism; a timer that starts a timing operation when the unlock detection means detects the unlock state of the lock mechanism; and a timer that times up after a predetermined time has elapsed; A keyless entry device for a vehicle, comprising: lock instruction means for instructing the lock mechanism to lock the lock mechanism.