Impact sensor for motor vehicle releasing safety device - has electronics with own power supply switched by piezoelectric acceleration or deceleration sensor

摘要

The impact sensor is installed in a sensor housing and serves to activate safety equipment if the vehicle hits an obstacle, i.e. inflate an air cushion or pull a safety belt tight. The housing contains an acceleration-deceleration sensor, an electronic threshold value setter and evaluator and perhaps also the ignition or release circuit for the safety arrangement. The power supply for the electronics, pref. a battery, is switched off when the vehicle is travelling. The switch is activated by impact with dependence on direction. The sensor for acceleration or deceleration can be a piezo-ring surrounding a ball and comprising elements distributed in the X and Y axes and coupled to the switch. ADVANTAGE - Threshold values easily and accurately set. No electrical leads required to vehicle energy source (on-board network).