JPH0732974A - Burglar prevention device for automobile - Google Patents

Abstract

PURPOSE:To provide the burglar prevention device for the time of engine suspension and of idling operations at low cost, and let the device be functioned by simple operations. CONSTITUTION:The burglar prevention device against the insertion of an informal key is made up of a formal key insertion detector 1, an engine revolution detecting circuit 2, a burglar prevention circuit 3, an alarm 4, an engine control unit 5 and of a relay 7, and a burglar prevention device for the time of engine idling operations is made up of the formal key insertion detector 1, the engine revolution detecting circuit 2, the burglar prevention circuit 3, the alarm 4, the engine control unit 5, the relay 7, a door lock detector 8, and of a side brake detector 9 as shown by the figure 4. By this constitution, the inexpensive, simple and effective burglar prevention device capable of positively preventing an automobile burglar, can thereby be provided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle antitheft device, and more particularly to a vehicle antitheft device which is suitable when the engine is warmed up and the driver leaves the vehicle.

[0002]

2. Description of the Related Art In a conventional device, an alarm is issued when a door lock is operated without inserting a key (Japanese Patent Laid-Open No. 63-255156), and the engine does not start unless the personal identification numbers match when getting on a vehicle. (Japanese Patent Laid-Open No. 59-57049), etc.
Although there was an antitheft device when the engine was off, the antitheft device when the engine was warming up was expensive and complicated to operate.

[0003]

The antitheft device for warming up the engine according to the prior art described above has a problem that the cost is high and the operation is complicated.

An object of the present invention is to provide an inexpensive anti-theft device which is easy to operate even when the engine is stopped and the engine is warmed up.

[0005]

The above object is to detect the engine speed when the engine is stopped (when the key is not inserted) and to perform a 4-digit personal identification number input operation on the keyboard during engine warm-up operation. Is achieved in.

[0006]

The vehicle antitheft device according to the present invention can prevent theft due to an illegal key operation when the engine is stopped or theft during warm-up operation.

[0007]

Embodiments of the present invention will be described below with reference to FIGS.
This will be described with reference to FIG.

FIG. 1 is a block diagram showing a first embodiment according to the present invention. Reference numeral 6 denotes a battery power source, and the anti-theft circuit 3 includes a regular key insertion detector 1 for discriminating the ignition key 1a and an ignition coil primary side signal 2a.
It is composed of a relay 7 which receives the engine speed detection circuit 2 for detecting the speed from the input, and shuts off the alarm device 4 and the control unit 5.

The normal key insertion detector 1 is of a contact type for discriminating normal key insertion / non-insertion, and the engine speed detection circuit 2 inputs the primary side signal 2a of the ignition coil to combine a differentiation circuit and an integration circuit. By this, an analog voltage is output, and the inclination of the characteristic example of FIG. 2 can be changed by combining a capacitor and a resistor. Anti-theft circuit 3
Is to output an alarm signal to the alarm device 4 and an engine control unit stop signal to the relay 7 in response to input signals from the regular key insertion detector 1 and the engine speed detection circuit 2. The alarm device 4 shares the horn of the automobile, and the engine control unit 5 indicates the engine control unit of the automobile. The engine control unit stop signal cuts off the battery power source 6 of the engine control unit 5 by the relay 7. Relay O
The N / OFF operation signal is sent in the anti-theft circuit 3.

Next, the operation of the present invention will be described with reference to the flowchart of FIG. In FIG. 3, the theft determination of the antitheft device starts from the state where the regular key is not inserted. Regular key insertion
When the judgment at 101 is Yes, the antitheft device is bypassed and the engine is started normally. Next, when the regular key insertion 101 is No, the process proceeds to the engine speed detecting means 102.
When the engine speed detecting means 102 is No, the routine goes to the same routine as when the regular key insertion 101 is No, and when Yes, the process shifts to the alarm generating means 103 and sends a signal to the engine control unit to make the engine control unit function. Stop and end.

FIG. 4 is a block diagram showing a second embodiment according to the present invention. 6 is a battery power source, and the anti-theft circuit 3 includes a regular key insertion detector 1 for discriminating the ignition key 1a and a door lock detector 8 (unlocking on the 8a side,
8b side is locked), a side brake detector 9 (9a side is a side brake working, 9b side is a side brake not working), an engine speed detection circuit 2 for detecting a speed from the ignition coil primary side signal 2a, and a personal identification number input device 1
It is composed of the output of the relay 7 which takes 0 as an input and shuts off the alarm device 4 and the control unit 5.

The normal key insertion detector 1 is of a contact type for discriminating normal key insertion / non-insertion, and the engine speed detection circuit 2 is similar to that of the first embodiment and has the characteristics shown in FIG. The anti-theft circuit 3 is a normal key insertion detection circuit 1, an engine speed detection circuit 2, a door lock detector 8, a side brake detector 9, and an input signal from a personal identification number input device 10. The stop signal is output to the relay 7. The door lock detector 8 and the side brake detector 9 are of a contact type, the alarm device 4 shares the horn of the automobile, and the engine control unit 5 indicates the engine control unit of the automobile. Further, the engine control unit stop signal cuts off the battery power source 6 of the engine control unit 5 by the relay 7, and the relay ON / OFF operation signal is given in the theft prevention circuit 3. PIN input device 1
For 0, a 4-digit number is operated by the keyboard, and when the verification of the input number by the microcomputer in the anti-theft circuit 3 matches the password, the engine is started. Send an engine control unit stop signal to 7.

Next, the operation of the present invention will be described with reference to the flowchart of FIG. In FIG. 5, the theft determination of the antitheft device starts from the regular key insertion state. Regular key insertion
When 201 is No, an alarm is generated and engine speed detection 2
03 is performed in the alarm standby state 202. It is determined that the engine is warming up 206 only when all of the engine speed detection 203, the door lock unlocking 204, and the side brake operation 205 are Yes, and otherwise the determination is ended. Next, the side brake operation 207 is judged by inputting 206 while the engine is warming up.
Only when all 08 are No, the warning sound is generated by the alarm device 4 for a predetermined time, and thereafter, the alarm generation 210 and the engine control unit stop 211 are performed, and the processing ends.

[0014]

According to the present invention, the antitheft device at the time of engine stop and engine warm-up operation can be inexpensively and easily operated.

[Brief description of drawings]

FIG. 1 is a block diagram showing a device configuration of a first embodiment of the present invention.

FIG. 2 is a graph showing a characteristic example of an engine speed (r / min) and an analog converted voltage (V).

FIG. 3 is a flow chart showing an alarm generation according to the first embodiment.

FIG. 4 is a block diagram showing a device configuration of a second embodiment of the present invention.

FIG. 5 is a flow chart showing an alarm generation according to the second embodiment.

[Explanation of symbols]

1 ... Regular key insertion detector, 2 ... Engine speed detection circuit, 3 ... Theft prevention circuit, 4 ... Alarm device, 5 ... Engine control unit, 7 ... Relay, 8 ... Door lock detector, 9 ... Side brake detector 10 ... PIN input device.

Claims (2)

[Claims] 1. An automobile theft prevention device comprising a regular key detecting means for detecting the insertion of a regular key of an ignition key and a means for detecting an engine speed from the primary side of an ignition coil. An anti-theft device for an automobile, comprising an anti-theft circuit for issuing an alarm activation signal and an engine control unit stop signal based on a non-insertion detection signal and an engine speed signal from a means for detecting the engine speed. 2. An antitheft device for a vehicle according to claim 1, wherein the key detection means, the engine speed detection means, the door lock detection means, and the side brake detection means determine the alarm activation standby state and a secret code. An anti-theft device for an automobile, comprising an anti-theft circuit composed of a number recognition means.