JPH04327668A - Automatic door locking device - Google Patents

Abstract

PURPOSE:To lock a door automatically without operating the locking of the door of a car. CONSTITUTION:A constant code signal is transmitted intermittently from a car device on the car side, and the signal is received by a reception section 7 in a transmitter 1. Whether or not the code is a fixed code is discriminated by a code discriminating section, and a reply code is formed from a code formation section 10 when the code is the fixed code and transmitted from a transmission section 15. The door of the signal is locked on the basis of the lowering of the signal level in a car device.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for automatically locking a vehicle door.

0002

2. Description of the Related Art Conventionally, a device for locking a vehicle door from the outside typically locks the door using a key. Further, a remote control device for locking or unlocking a vehicle door without using a key by transmitting a predetermined code signal by infrared rays or radio is also disclosed in, for example, Japanese Patent Laid-Open No. 101771/1983.

0003

However, with such conventional remote control devices, it is necessary for the driver to lock the vehicle doors before leaving the vehicle. Therefore, if this operation is forgotten, or if the vehicle door is not locked for some reason even after performing the locking operation using the remote control device, there is a problem that there is a risk of theft or the like.

The present invention has been made in view of the problems of conventional remote control devices, and is designed to prevent theft due to forgetting to lock the door and to securely lock the vehicle door without having to perform a locking operation. The technical challenge is to do so.

[0005]

[Means for Solving the Problems] The present invention is an automatic door lock device including a transmitting device and a vehicle device installed in a vehicle and receiving a signal from the transmitting device, the transmitting device comprising:
a receiving section that receives and demodulates a signal of a predetermined frequency; a code identification section that identifies a fixed code based on the signal obtained from the receiving section; and a code identification section that generates a reply code when a certain fixed code is received from the code identification section. A transmitter that transmits a fixed code by radio waves at a certain level, and a vehicle device on the vehicle side includes a transmitter that transmits a fixed code by radio waves when the door of the vehicle is unlocked, and a transmitter that transmits a fixed code by radio waves when the door of the vehicle is unlocked. a receiving section that receives a signal obtained from the transmitting device after the fixed code is transmitted; a code identifying section that determines whether the signal obtained from the receiving section is a reply code; and a code identifying section that determines whether the signal obtained from the receiving section is a reply code or not; The present invention is characterized by comprising a level detection section that detects a decrease, and a door lock control section that locks the vehicle door when a detection signal is obtained from the level detection section.

[0006]

[Function] According to the present invention having such characteristics, a fixed code is intermittently transmitted from the transmitter on the vehicle device side at predetermined time intervals, and then a signal is received from the transmitter. When the transmitter receives this fixed code signal,
The code identification section identifies whether or not a fixed code is included, and if a fixed code is included, the transmitting section sends out a reply code at a certain level. When the vehicle device receives a reply code, it identifies whether the reception level is below a predetermined level, and if it is below a predetermined level, it is determined that the transmitting device has moved away and the person has left the vehicle.
Vehicle doors are automatically locked.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a block diagram showing the configuration of a transmitting apparatus according to an embodiment of the present invention. It is assumed that the transmitting device 1 is integrated with the ignition key of the vehicle or used together with the ignition key. As shown in the figure, a transmitter 1 has an antenna 2 connected to an antenna switch (ANTSW) 3 for switching the antenna. As shown in the figure, the antenna switch 3 includes a receiving section 7 consisting of a tuning circuit 4, an amplifying circuit 5, and a demodulating circuit 6 for receiving a signal of a predetermined frequency.
is connected. The receiving section 7 outputs the signal demodulated by the demodulation circuit 6, and the output is given to the code identification section 8. The code identification unit 8 identifies whether a fixed code is included when receiving a signal, and if a fixed code is included, a matching signal is sent to the trigger circuit 9.
, is given to the code generation unit 10. The trigger circuit 9 provides a trigger signal for sending a reply code to the code generation section 10 based on this signal. Code generator 10
provides a signal containing a reply code to the modulation circuit 11 based on these signals. The output of the modulation circuit 11 is the oscillation circuit 12
is applied to control the oscillation. The oscillation output is connected to the antenna switch 3 via a tuning circuit 13 and an amplifier circuit 14. Here, the modulation circuit 11, the oscillation circuit 12,
The tuning circuit 13 and the amplifier circuit 14 constitute a transmitter 15 that transmits a reply code signal at a constant level.

Next, FIG. 2 is a block diagram showing the configuration of a vehicle device 20 used in correspondence with this transmitting device 1. As shown in FIG. In this figure, a vehicle device 20 has an antenna 21 connected to an antenna switch 22, and one end of the antenna switch 22 connected to a receiving section 26 consisting of a tuning circuit 23, an amplifier circuit 24, and a demodulation circuit 25. The output of the amplifier circuit 24 is also given to a level detection circuit 27. The level detection circuit 27 identifies whether the level of the received signal is below a predetermined value, and its output is given to the CPU 28. C.P.
U28 sends out a code signal at predetermined time intervals as will be described later, and controls the locking of the door based on the returned signal. A motor driver 3 including a forward/reverse relay etc. is connected to the CPU 28 via an output interface 29.
0 and the door lock motor 31 are connected. The output interface 29, motor driver 30, and door lock motor 31 constitute a door lock control section 32 that drives the vehicle door in the locking direction. Further, a door lock switch 33 is provided for detecting the locked or unlocked state of each of the driver's seat, passenger seat, and rear doors of the vehicle, and the outputs thereof are given to the CPU 28 via an input interface 34. CPU 28 also provides a fixed code signal to modulation circuit 35. The modulation circuit 35, oscillation circuit 36, tuning circuit 37, and amplifier circuit 38 constitute a transmitting section 39 that sends out a constant code signal.

Next, the operation of this embodiment will be explained with reference to the flow chart of FIG. 3 and the time chart of FIG. 4. In the auto door lock mode, the vehicle device 20 on the vehicle side first activates the door lock switch 33 in step 41.
It is determined whether at least one of the doors is unlocked. If all the doors are locked, the reception acceptance flag is reset (step 42), and the process ends; if all the doors are unlocked, the process proceeds to step 43, where a fixed code is given to the modulation circuit 35. Then, the fixed code is transmitted from the transmitter 39 at a constant frequency. Then, the vehicle device 20 side waits for a short time in step 44, and then proceeds to step 45 to check whether the fixed code is received.

Now, if the transmitting device 1 is in an area where this fixed code signal can be received, the fixed code signal will be received via the antenna 2, the antenna switch 3, and the receiving section 7, and the fixed code signal will be received by the code identifying section 8. The fixed code is identified by . If the fixed code is received, the trigger circuit 9
A reply code is generated by the code generation unit 10 via
A reply code is sent from the transmitter 15 at a constant level. In step 45, the reception of the reply code is awaited.
If a signal is received, it is checked to see if it matches the reply code. When the reply code is received, it is determined based on the output of the level detection circuit 27 whether the reception level is a low level below a predetermined value (step 46). If the reception level exceeds a predetermined value, the process proceeds to step 47 where a reception acceptance flag is set, and if it is below the predetermined level, a lock signal is output to the output interface 29 for, for example, 0.5 seconds in step 48. Then, the door lock motor 31 is driven via the output interface 29 and the motor driver 30, and the unlocked door is locked.

On the other hand, if the reply code is not received in step 45, the process advances to step 49 and it is checked whether the reception acceptance flag is set. If this flag is not set, it is considered that the transmitting device 1 does not exist, so the process proceeds to step 42 and ends. In addition, if the reception acceptance flag has already been set, the reply code will be received once, and it will be determined that the driver holding the transmitter went out of the range of radio waves during the suspension period, so the process will start from step 49. Proceeding to step 48, a lock signal is output for a short time to lock the vehicle door. Here the CPU
28 fulfills the function of a code identifying means 28a that determines whether the received signal given from the receiving section 26 matches the reply code in step 45.

As shown in FIG. 4, such an operation is performed intermittently at intervals of a predetermined period of time, for example, several seconds to several tens of seconds, and is paused during this period. In this way, the small transmitter 1
The consumption of the built-in battery can be reduced.

[0013]

[Effects of the Invention] As explained in detail above, according to the present invention, a certain code signal is sent from the vehicle device on the vehicle side, and
The transmitter receives this signal and sends out a reply code at a constant level, so the vehicle's device locks the vehicle doors based on the drop in the signal level. In this way, when the driver leaves the vehicle, there is no need to perform a special locking operation, and the vehicle doors can be automatically locked. Therefore, no locking operation is required, and it is possible to reliably prevent the vehicle from being stolen.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the configuration of a transmitting device according to an embodiment of the present invention.

FIG. 2 is a block diagram showing the configuration of the vehicle device of this embodiment.

FIG. 3 is a flowchart showing the operation of the vehicle device of this embodiment.

FIG. 4 is a time chart showing the operation of the vehicle device of this embodiment.

[Explanation of symbols]

1 Transmitting device 2,21 Antenna 3,22 Antenna switch 7, 26 Receiving section 8 Code identification section 9 Trigger circuit 10 Code generation section 15, 39 Transmission section 20 Vehicle equipment 27 Level detection circuit 28 CPU 28a Code identification means 31 Door lock motor 33 Door lock switch

Claims (1)

[Claims] 1. An automatic door lock device including a transmitting device and a vehicle device installed in a vehicle and receiving a signal from the transmitting device, wherein the transmitting device receives and demodulates a signal of a predetermined frequency. a receiving section; a code identification section that identifies a fixed code based on a signal obtained from the receiving section; and a code identification section that transmits a reply code at a certain level by radio waves when a certain fixed code is received from the code identification section. A transmitter, the vehicle device on the vehicle side includes a transmitter that transmits the fixed code by radio waves when the door of the vehicle is in an unlocked state, and a transmitter that transmits the fixed code after transmitting from the transmitter. a code identification unit that determines whether the signal obtained from the receiving unit is a reply code; and a code identification unit that detects a decrease of the received signal below a predetermined level when the fixed code is received. a door lock control unit that locks a door of the vehicle when a detection signal is obtained from the level detection unit;
An automatic door lock device comprising: