# US 10,502,646 B2 · Magnetostrictive sensor, magnetic structure and production method thereof, motor drive device provided with magnetostrictive sensor, and motorassisted bicycle > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,502,646 B2 - Document ID: US10502646B2 - Status: Granted - Kind: B2 - Application number: 15/852,700 - Filed: 2017-12-22 - Published: 2018-05-03 - Granted: 2019-12-10 - Earliest claimed: 2015-06-23 - Assignees: Yamaha Hatsudoki Kabushiki Kaisha - Applicants: Yamaha Hatsudoki Kabushiki Kaisha - Inventors: Satomi Ishikawa; Hiroshi Matsumoto - Web page: https://patentgrep.com/patent/US10502646B2 ## CPC - G01L 3/102: {involving magnetostrictive means (magnetostrictive sensors H10N35/101)} - B62M 6/50: characterised by detectors or sensors, or arrangement thereof - G01L 3/103: {Details about the magnetic material used} - G01L 3/105: {involving inductive means (G01L3/102, G01L3/104 take precedence)} - H10N 35/101: {with mechanical input and electrical output, e.g. generators, sensors} - G01L: MEASURING FORCE, STRESS, TORQUE, WORK, MECHANICAL POWER, MECHANICAL EFFICIENCY, OR FLUID PRESSURE (weighing G01G) - B62M: RIDER PROPULSION OF WHEELED VEHICLES OR SLEDGES; POWERED PROPULSION OF SLEDGES OR {SINGLE-TRACK} CYCLES; TRANSMISSIONS SPECIALLY ADAPTED FOR SUCH VEHICLES (arrangements or mounting of transmissions in vehicles in general B60K; transmission elements per se F16) - H10N: ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR ## Abstract A magnetostrictive sensor including a magnetic structure. The magnetic structure has a columnar substrate extending along an axis, and a magnetostrictive portion disposed on an outer peripheral surface of the substrate. The magnetostrictive portion includes a plurality of portions that have different concentrations of at least one of a plurality of elements, the portions being so arranged as to satisfy at least one of a first requirement that in a first cross sectional view of the magnetostrictive portion orthogonal to the axis, the portions are arranged clockwise about the axis, a second requirement that in the first cross sectional view, the portions are arranged in a thickness direction of the magnetostrictive portion, and a third requirement that, in a second cross sectional view of the magnetostrictive portion that is orthogonal to the first cross sectional view and passes through the axis, the portions are arranged along the axis. ## Claims ### Claim 1 A magnetostrictive sensor, comprising: a magnetic structure, including a columnar substrate extending along an axis, and a magnetostrictive portion disposed on an outer peripheral surface of the substrate, and containing a plurality of elements, wherein the magnetostrictive portion including a plurality of portions that have different concentrations of at least one of the plurality of elements, the portions being so arranged as to satisfy at least one of a first requirement that in a first cross sectional view of the magnetostrictive portion orthogonal to the axis, the portions having different concentrations of the at least one element are arranged clockwise about the axis, a second requirement that in the first cross sectional view, the portions having different concentrations of the at least one element are arranged in a thickness direction of the magnetostrictive portion, and a third requirement that, in a second cross sectional view of the magnetostrictive portion that is orthogonal to the first cross sectional view and passes through the axis, the portions having different concentrations of the at least one element are arranged along the axis. ### Claim 2 (depends on 1) The magnetostrictive sensor of claim 1, wherein the at least one element is an element forming a ferromagnet. ### Claim 3 (depends on 1) The magnetostrictive sensor of claim 1, further comprising a coil disposed to surround the columnar substrate and the magnetostrictive portion formed thereon. ### Claim 4 (depends on 3) The magnetostrictive sensor of claim 3, wherein the coil comprises a plurality of coils arranged side by side along the axis. ### Claim 5 (depends on 1) The magnetostrictive sensor of claim 1, wherein the magnetostrictive portion contains at least a metal selected from the group consisting essentially of Ni, Fe, Co and Cr. ### Claim 6 (depends on 1) The magnetostrictive sensor of claim 1, wherein the magnetostrictive portion includes a plurality of magnetostrictive lines, which include adjacent first and second magnetostrictive lines that extend along an extension direction and are disposed on the outer peripheral surface of the substrate via respectively first and second contact areas, and in a third cross sectional view of the magnetostrictive portion taken orthogonally to the extension direction, a first length, which is a width of a widest portion of the first magnetostrictive line in a width direction parallel to the outer peripheral surface of the substrate, is larger than a second length that is a width of the first contact area in the width direction, and than a third length that is a shortest distance between the first and second contact areas in the width direction. ### Claim 7 (depends on 6) The magnetostrictive sensor of claim 6, wherein in the third cross sectional view, the first length is larger than a height of the first magnetostrictive line in a height direction perpendicular to the outer peripheral surface of the substrate. ### Claim 8 (depends on 6) The magnetostrictive sensor of claim 6, wherein in the third cross sectional view, a height of the first magnetostrictive line, in a height direction perpendicular to the outer peripheral surface of the substrate, is larger than a first distance between the widest portion of the first magnetostrictive line and the outer peripheral surface of the substrate in the height direction. ### Claim 9 (depends on 8) The magnetostrictive sensor of claim 8, wherein in the third cross sectional view, a half of the height of the first magnetostrictive line is greater than or equal to the first distance. ### Claim 10 (depends on 6) The magnetostrictive sensor of claim 6, wherein in the third cross sectional view, a shortest distance between the first and second magnetostrictive lines in the width direction, between any portions thereof, is larger than zero. ### Claim 11 (depends on 1) A motor-driven device, comprising the magnetostrictive sensor of claim 1. ### Claim 12 (depends on 1) An electric motor-assisted bicycle, comprising the magnetostrictive sensor of claim 1. ### Claim 13 A magnetostrictive structure, comprising: a columnar substrate extending along an axis; and a magnetostrictive portion disposed on an outer peripheral surface of the substrate, and containing a plurality of elements, wherein the magnetostrictive portion including a plurality of portions that have different concentrations of at least one of the plurality of elements, the portions being so arranged as to satisfy at least one of a first requirement that in a first cross sectional view of the magnetostrictive portion orthogonal to the axis, the portions having different concentrations of the at least one element are arranged clockwise about the axis, a second requirement that in the first cross sectional view, the portions having different concentrations of the at least one element are arranged in a thickness direction of the magnetostrictive portion, and a third requirement that, in a second cross sectional view of the magnetostrictive portion that is orthogonal to the first cross sectional view and passes through the axis, the portions having different concentrations of the at least one element are arranged along the axis. ### Claim 14 (depends on 13) A method for fabricating the magnetic structure of claim 13, the method comprising the steps of: forming a resist layer having a predetermined pattern on the outer peripheral surface of the substrate; and forming the magnetostrictive portion on the outer peripheral surface of the substrate on which the resist layer is disposed.