Title: Magnetostrictive torque sensor and electrically powered steering apparatus using same
Application Number: 200610163573 Application Date: 2006.10.08
Publication Number: 1952637 Publication Date: 2007.04.25
Approval Pub. Date: Granted Pub. Date:
International Classifi-cation: G01L3/04;G01L3/10;B62D6/10
Applicant(s) Name: Honda Motor Co., Ltd. Address:
Inventor(s) Name: Harata Hitoshi;Doi Mizuho;Karasawa Hitoshi;Hoshi T
Attorney & Agent: magao beng
Abstract:
    A magnetostrictive torque-sensor (10) comprising a first magnetostrictive film (14A), a second magnetostrictive film (14B), and a third magnetostrictive film (14C) formed over the entire circumferential periphery of a surface of a rotating shaft (11). A first sensor coil (13A), a second sensor coil (13B), and a third sensor coil (13C) for sensing changes in impedance are provided for the first, second, and third magnetostrictive films, respectively. Signals according to the changes in impedance outputted from the first through third sensor coils are inputted to a torque calculating unit (17). The torque calculating unit (17) calculates the torque applied to the rotating shaft on the basis of the output signal from the first sensor coil and the output signal from the second sensor coil. Furthermore, the output signals from the first through third sensor coils are compared, and failures in the first magnetostrictive film or the second magnetostrictive film are detected by a failure detector (18).
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