| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a vehicle theft prevention device capable of easily detecting a theft action to hoist and move a vehicle by a wrecker, a crane vehicle or the like. <P>SOLUTION: The vehicle theft prevention device comprises a spring length detection means 11 consisting of an ultrasonic wave type displacement sensor or a magnetic type displacement sensor capable of acquiring the length L of an extending/contracting coil spring 23 of a suspension connected to a wheel of a vehicle and a determination unit 16 to determine the theft of the vehicle when the length L of the coil spring 23 acquired by the spring length detection means 11 is equal to or greater than a predetermined value Lo, and further comprises a sound generating means 20 to generate a warning alarm when the theft is determined by the determination unit 16, and a reporting unit 17 to perform the automatic reporting to the police or a user of the vehicle via the telephone or the electronic mail. <P>COPYRIGHT: (C)2005,JPO&NCIPI |
