ACCELERATION SENSOR, ACCELERATION SENSOR SYSTEM, VEHICLE EQUIPPED WITH ACCELERATION SENSOR SYSTEM, AND OTHER DEVICES

摘要

PURPOSE:To detect acceleration in only a desired direction without being affected by accelerations excluding that in the desired direction by setting the acceleration detecting direction so that the output caused by the acceleration crossing the acceleration detecting direction at a right angle may become the minimum. CONSTITUTION:An axial direction X for detecting acceleration is set to cross vertically a plane L including a rocking center M of the center of gravity M and the center of gravity G in a mass part 4. Therefore, when an acceleration in the direction X is applied thereto, the part 4 is displaced due to elastic deformation of a beam 3, and the gap amount of a movable electrode 5 and fixed electrode 7 is changed according to the displacement, so that the acceleration change in the direction X may be detected based on the change in electrostatic capacity between the both electrodes. In case of axial direction Y, since an inertia force applied to the center of gravity G at this acceleration passes through the center M, no bending moment is generated in the beam 3 and detection sensitivity for acceleration becomes about zero. In addition, in case of widthwise direction, since the part 4 is supported by a plurality of beams 3 placed in the widthwise direction, the part 4 is hardly changed and the detection sensitivity becomes zero. Therefore, the accelerations in only the direction X can be detected.