TWO-DIMENSIONAL ACCELERATION SENSOR

摘要

PURPOSE:To secure excellent durability and to make it possible to ensure the detection of acceleration in the direction of multiple axes without the effect of rotation by omitting mechanical contact and sliding parts in a simple constitution comprising magnetic fluid and a permanent magnet. CONSTITUTION:A permanent magnet 5 is moved to a position where receiving acceleration is balanced with magnetic viscoelasticity generated by a magnetic fluid 4 between a returning-force generating member and the poles of the magnet 5. The displacement in said movement occurs in the directions of multiple axes along the directions of the poles of the magnet 5. The displacement is detected with a magnetism detecting means. An acceleration computing means computes the acceleration based on the detected signal. A rotation preventing member is provided so as to face a part between the poles of the magnet 5. Therefore, magnetic viscoelasticity which suppresses the rotary motion of the magnet 5 acts between the high density part of the fluid 4 in the vicinity of the poles and the rotation preventing member. Since the rotation of the magnet 5 is prevented in this way, only the displacement of the magnet 5 caused by the acceleration can be detected positively without the effect of the displacement of the poles caused by the rotation.