| 摘要 |
PURPOSE:To reduce variance at the time of manufacture and to increase pressure detection accuracy by forming a closed magnetic path of a columnar soft magnetic body, a nonmagnetic disk which has grooves corresponding to the groove part of the body 1 and many small holes 3a, and one amorphous alloy disk which has magnetic strain. CONSTITUTION:The closed magnetic path consists of the soft magnetic body 1, the nonmagnetic disk 3 having grooves 3 at parts corresponding to its groove parts and numbers of small holes 3a, and the amorphous magnetic alloy disk 2 having magnetic strain. The disk 2 is pressed down at groove parts 3b and small holes 3a with pressure from a pressure intake 4a to generate internal stress in the disk 2, the alloy 2 decreases in magnetic permeability owing to its magnetostrictive effect, and this variation is detected by a coil 8 in the form of inductance. Therefore, a magnetic circuit is stabilized by the spacer 3 of the nonmagnetic disk to reduce variance at the time of manufacture and improve the detection accuracy of pressure.
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