JPH03125651A - Burglary prevention device of vehicle - Google Patents

Abstract

PURPOSE:To prevent burglary effectively by stopping the driving of a steering motor for rotating a steering when vehicle burglary is are detected by a burglary detecting means. CONSTITUTION:In the control part 3 of a power steering control unit 2 which inputs the output signal of a torque sensor 1, a vehicle speed signal and an engine speed signal, an assist signal is outputted according to the then input, and with the assist signal, a steering motor 5 is driven and controlled through a motor drive circuit 4. In a vehicle provided with the power steering device, there is provided a burglary detecting means 7 which detects burglary by detecting the change in the frequency of an ultrasonic signal in a vehicle, for example. When burglary is detected, the vehicle is made substantially inoperable by stopping the driving of the steering motor 5 or setting the energizing direction to the steering motor 5 oppositely.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an anti-theft device for a vehicle having a power steering device.

[Conventional technology]

Conventional anti-theft devices for parked vehicles are, for example, disclosed in Japanese Patent Application Laid-Open No. 1983-
As shown in No. 46952, vehicle theft is detected by installing an ultrasonic sensor inside the vehicle and detecting frequency changes due to the Doppler effect of the received ultrasonic waves. Theft was prevented by prohibiting the start of the vehicle's engine, issuing an alarm, or turning on the headlights.

[Problem to be solved by the invention]

However, such conventional anti-theft devices have the disadvantage that the steering wheel of the vehicle can be rotated freely, so the vehicle may be taken away depending on the theft method.

The present invention has been made in view of the problems of conventional vehicle theft prevention devices, and provides a technology to effectively prevent theft by disabling steering operation when theft is detected. This will be a major issue.

[Means to solve the problem]

The present invention includes a theft detection means for detecting theft of a vehicle, a steering motor for rotating a steering wheel, and a steering motor that drives the steering motor based on a predetermined input and that responds to the input by a theft detection signal from the theft detection means. The present invention is characterized by comprising a steering motor drive means for stopping the drive to the motor.

[Effect]

According to the present invention having such characteristics, when the theft detection means detects theft of the vehicle, the steering motor drive means stops normal steering operation corresponding to the input, so that the steering cannot be used.

〔Example〕

FIG. 1 is a block diagram showing the overall configuration of an anti-theft device according to an embodiment of the present invention. In this figure, the output of a torque sensor 1, a vehicle speed signal, and an engine rotation signal are given to a control section 3 of a power steering control unit 2. The control section 3 is realized by a microcomputer having a CPU, a memory, and an input/output interface, and outputs an assist signal in response to input, and the output is given to the motor drive circuit 4. The motor drive circuit 4 is supplied with an output, such as a PWM modulation signal, which changes with respect to the input level and direction of the torque sensor 1 or the like. The motor drive circuit 4 drives the steering motor 5 in a specified direction based on these signals.

Further, a switch signal from an ignition switch 6 is applied to the control section 3, and a theft detection means 7 is further connected to the power source of the vehicle. The theft detection means 7 includes, for example, an ultrasonic oscillator and a receiver that oscillates ultrasonic waves inside the vehicle, and detects theft by detecting a change in the frequency of the ultrasonic signal inside the vehicle.

The theft detection signal is then given to the control section 3 of the control unit 2. A transistor T is connected to the output terminal of the control section 3.
A relay 11 for changing the current direction of the steering motor is connected via ri.

FIG. 2 is a time chart showing the operation of this embodiment.

In this figure, if the ignition switch 6 is turned on after the theft detection means 7 detects theft of the vehicle,
The relay 11 for switching the drive motor between forward and reverse directions is energized.

Therefore, the direction of energization to the steering motor 5 is switched to the opposite direction from the normal direction. Therefore, from now on, when the stolen vehicle tries to drive the vehicle by operating the steering wheel, the signal from the torque sensor 1, the vehicle speed signal,
Power steering is performed by the control unit 3 based on the engine rotation signal, but the direction of energization to the steering motor 5 is reversed. Therefore, the steering wheel is operated in a direction different from the direction of operation, making it virtually impossible to drive the vehicle. Therefore, vehicle theft can be effectively prevented.

In the embodiment described above, the driving direction of the steering motor is reversed when theft is detected, but as shown in FIG. 3, both ends of the steering motor may be short-circuited when theft is detected. In this case, when theft is detected, the shorting relay 12 is energized via the transistor Tr2, and both ends of the steering motor 5 are shorted. Therefore, the steering motor 5 becomes a load and the steering becomes extremely heavy, making it impossible to perform effective steering operations. Therefore, in this case as well, the power steering device can be used to effectively prevent vehicle theft.

〔Effect of the invention〕

As described above, according to the present invention, since the steering operation is prohibited by the output of the theft detection means, it is possible to reliably prevent vehicle theft.

[Brief explanation of the drawing]

Fig. 1 is a block diagram showing the overall configuration of a vehicle anti-theft device according to an embodiment of the present invention, Fig. 2 is a time chart showing its operation, and Fig. 3 is a block diagram showing another embodiment of the present invention. It is. ■・・・−・−Torque sensor 2・・−−−−Power steering control unit 3−・・−・
Control jH section 4 --- Motor drive circuit 5 ---
---Steering motor 6...Ignition switch 7--Theft detection means 11.1
2-...-Relay 1st Figure 2- ・----Nogworth ↑ Alisogekkotrol λ knit 5 ・--・-S ↑ Finished Sogeshi 1st 11------・-゛ru'th figure

Claims (1)

[Claims] (1) a theft detection means for detecting theft of a vehicle; a steering motor for rotating the steering wheel; and a steering motor for driving the steering motor based on a predetermined input and for responding to the input by a theft detection signal from the theft detection means. An anti-theft device for a vehicle, comprising: steering motor drive means that stops driving the steering motor.