Toyota Jidosha Kabushiki Kaisha

Sumitomo Special Metals Co., Ltd.

Hideo Hayashi

Kazushi Kuroda

Kentaro Ogata

A displacement detection device and a wire therefor in which the drawbacks of the conventional Elinvar-type alloy are eliminated, the magnetostriction intensity as well as the magnetostriction propagation speed does not vary with temperature, and a magnetostriction coefficient is sufficiently great to enable an amplification at a high speed of response to be unnecessary. A magnetostrictive wire used in a displacement detection device together with a magnetostriction-generating magnet disposed close thereto and movable relative thereto, said wire substantially composed of 35 to 60 wt % Ni and the balance consisting of Fe and unavoidable impurities, cold-wire-drawn and then heat-treated and having a magnetostriction coefficient greater than that exhibited in an as-cold-wire-drawn state. A displacement detection device includes the above-mentioned magnetostrictive wire and a magnetostrictive-generating magnet disposed movable relative thereto and therealong for detecting a relative displacement between the magnetostrictive wire and the magnet based on a time of propagation, through the wire, of a magnetostriction signal generated in the wire in the portion close to the magnet by a pulse current applied to the wire.

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Takatsuki, Japan

Hideo Hayashi