| 摘要 |
<p>PURPOSE:To prevent tires from being stolen via jack-up by performing the jack-up detection of a car body with a shock sensor and a ultrasonic sensor and correctly identifying cases when the car body is hit and when it is jacked up. CONSTITUTION:A shock sensor 1 detecting shocks applied to a car body and an ultrasonic sensor 2 detecting the movement of personnel in a car room are provided. The first and second level comparing means 3, 4 comparing detection signals of individual sensors 1, 2 with reference values respectively are provided, the continuous time in which the shock sensor detection signal exceeds the reference value is measured by a measuring means 5, and whether this continuous time exceeds the predetermined reference time or not is detected by a time comparing means 6. If the shock sensor detection signal exceeds the reference value and the ultrasonic sensor detection signal is the reference value or lower and the continuous time exceeds the reference time, an output is generated from a judging means 7, a warning means 8 is operated, thus the theft of tires via jack-up is prevented.</p> |
