| 摘要 |
PROBLEM TO BE SOLVED: To provide a magnetostrictive displacement detector capable of accurately detecting the position of a detecting permanent magnet even if the detecting permanent magnet 18 moves in a wide area. SOLUTION: A current pulse flows in the axial direction of a magnetorestriction line 1 to generate a torsional elastic wave at a part of the magnetorestriction line 1 to which a detecting permanent magnet 9 movable along the magnetorestriction line 1 approaches, the propagation time of the torsional elastic wave to a receiving coil 7a is measured to detect the mechanical displacement given to a detecting permanent magnet 9, a biasing permanent magnet 10 for giving a deflection magnetic field in the axial direction is disposed near the receiving coil 7a to detect the longitudinal wave among the torsional elastic wave components propagating on the magnetorestriction line, using the coil 7a, the longitudinal wave is less attenuated, depending on the propagation distance, than the transversal wave and if the detecting permanent magnet 9 moves in a wide area, a clear detected waveform can be obtd.
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