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An acceleration sensor for detecting an acceleration in a plane, and having a housing, and a disk magnet arranged in a magnetic fludi stored in the housing. The movement of disk magnet is limited, i.e., a translational movement or rotational movement thereof can occur only in the plane, by projectio

An acceleration sensor for detecting an acceleration in a plane, and having a housing, and a disk magnet arranged in a magnetic fludi stored in the housing. The movement of disk magnet is limited, i.e., a translational movement or rotational movement thereof can occur only in the plane, by projections formed in the housing, between which projections portions of the magnetic fluid having an increased density are formed adjacent to the poles of the disk magnet so that only a translational movement is allowed, or by small circumferential walls between the housing and the disk magnet and radial projections formed between end walls of the housing and disk magnet so that only a rotational movement is allowed. A Hall element issues a signal corresponding to a position of the disk magnet, to thereby determine the acceleration rate.

대표청구항 ▼

A sensor for detecting an acceleration, comprising: a housing made of a non-magnetic material and defining therein a chamber having a substantially tubular shape, said chamber defining a circumferential wall and axially spaced side walls; a magnetic fluid stored in said tubular chamber; a disk-shape

A sensor for detecting an acceleration, comprising: a housing made of a non-magnetic material and defining therein a chamber having a substantially tubular shape, said chamber defining a circumferential wall and axially spaced side walls; a magnetic fluid stored in said tubular chamber; a disk-shaped permanent magnet arranged in said tubular chamber, said disk magnet defining a circumferential outer wall and axially spaced side walls, and said disk magnet having angularly spaced pole portions which form a magnetic field adjacent thereto so that portions having a locally increased density of the magnetic fluid are formed adjacent to said pole portions along the circumferential outer wall and side walls of the disk magnet; magnetic sensor means fixedly mounted on the housing for detecting changes in a magnetic flux from said pole portions of the disk magnet opposite to the sensor means, caused by a movement of the disk magnet relative to the housing; said magnetic sensor means sensing a position of the disk magnet at which an inertia of the disk magnet generated by the acceleration is balanced by a magnetic viscous elastic force of the magnetic fluid caused by said locally increased portion of the magnetic fluid in the chamber between circumferential outer wall of the disk magnet and the circumferential wall of the chamber; a spacing between the facing axially spaced side walls of the disk magnet and the chamber being such that axial movement of the disk magnet is substantially prevented, and: means for limiting movement of the disk magnet so that substantially only a kind of movement of the disk magnet relative to the housing in the plane of the disk magnet when an acceleration takes place can be obtained, thereby enabling a precise detection of a rate of the acceleration by the magnetic sensor means.