# US 11,112,321 B2 · Torque detection device and sensor module > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,112,321 B2 - Document ID: US11112321B2 - Status: Granted - Kind: B2 - Application number: 16/590,717 - Filed: 2019-10-02 - Published: 2020-02-06 - Granted: 2021-09-07 - Earliest claimed: 2017-04-28 - Assignees: Denso Corporation; Soken, Inc. - Applicants: Denso Corporation; Soken, Inc. - Inventors: Ken Tanaka; Shigetoshi Fukaya; Toshiro Suzuki; Satoru Jinno - Web page: https://patentgrep.com/patent/US11112321B2 ## CPC - G01L 3/104: {involving permanent magnets} - B62D 6/10: characterised by means for sensing {or determining} torque - G01L 5/221: {to steering wheels, e.g. for power assisted steering} - G01R 33/0047: {Housings or packaging of magnetic sensors (packaging of semiconductor devices H10W99/00); Holders} - G01R 33/072: {Constructional adaptation of the sensor to specific applications} - G01L: MEASURING FORCE, STRESS, TORQUE, WORK, MECHANICAL POWER, MECHANICAL EFFICIENCY, OR FLUID PRESSURE (weighing G01G) - B62D: MOTOR VEHICLES; TRAILERS (steering, or guiding on a desired track, of agricultural machines or implements A01B69/00; wheels, castors, axles, increasing wheel adhesion B60B; vehicle tyres, tyre inflation or tyre changing B60C; connections between vehicles of a train or the like B60D; vehicles for use on rail and road, amphibious or convertible vehicles B60F; suspension arrangements B60G; heating, cooling, ventilating or other air treating devices B60H; windows, windscreens, non-fixed roofs, doors or similar devices, protective coverings for vehicles not in use B60J; propulsion plant arrangements, auxiliary drives, transmissions, controls, instrumentation or dashboards B60K; electric equipment or propulsion of electrically-propelled vehicles B60L; power supply for electrically-propelled vehicles B60M; passenger accommodation not otherwise provided for B60N; adaptations for load transportation or to carry special loads or objects B60P; arrangement of signalling or lighting devices, the mounting or supporting thereof or circuits therefor, for vehicles in general B60Q; vehicles, vehicle fittings or vehicle parts not otherwise provided for B60R; servicing, cleaning, repairing, supporting, lifting, or manoeuvring, not otherwise provided for, B60S; brake arrangements, brake control systems or parts thereof B60T; air-cushion vehicles B60V; motor-cycles, accessories therefor B62J, B62K; testing of vehicles G01M) - G01R: MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES (indicating correct tuning of resonant circuits H03J3/12) ## Abstract A torque detection device includes a first magnetic circuit part, a second magnetic circuit part, a circuit board module, and a sensor housing. The first magnetic circuit part is disposed on one side of a multipolar magnet in an axial direction. The second magnetic circuit part is disposed on the other side of the multipolar magnet in the axial direction. The circuit board module includes plural magnetic sensors mounted thereon and facing the magnetic circuit on one end side in a width direction being included in the plane and intersecting the arrangement direction. The sensor housing is coupled to one end side in the arrangement direction of the circuit board module so as to support the circuit board module on the one end side in the arrangement direction of the circuit board module. ## Claims ### Claim 1 A torque detection device configured to output an electric signal corresponding to a torsional torque generated in a torsion bar that coaxially couples a first shaft and a second shaft together on a rotation center axis, the torsional torque being caused by relative rotation between the first shaft and the second shaft about the rotation center axis, the torque detection device comprising: a first magnetic circuit part disposed on one side of a multipolar magnet in an axial direction parallel to the rotation center axis, the multipolar magnet being configured in such a manner that magnetic poles are alternately inverted in a circumferential direction surrounding the rotation center axis and being disposed coaxially with the torsion bar so as to rotate about the rotation center axis along with the relative rotation; a second magnetic circuit part disposed on the other side of the multipolar magnet in the axial direction; a plurality of magnetic sensors disposed between the first magnetic circuit part and the second magnetic circuit part so as to output an electric signal corresponding to a magnetic flux density in a magnetic circuit formed by the first magnetic circuit part and the second magnetic circuit part, the plurality of magnetic sensors being arranged in an arrangement direction included in a plane intersecting the axial direction; a circuit board module including the plurality of magnetic sensors mounted thereon and facing the magnetic circuit on one end side in a width direction, the width direction being included in the plane and intersecting the arrangement direction; and a sensor housing coupled to one end side in the arrangement direction of the circuit board module so as to support the circuit board module on the one end side in the arrangement direction of the circuit board module, wherein the circuit board module has a waterproof structure that covers a plurality of circuit elements including the plurality of magnetic sensors and a circuit board on which the plurality of circuit elements are mounted with a waterproof covering member, a waterproof seal member is disposed on a coupling part between the sensor housing and the circuit board module, the waterproof seal member is formed in a ring-like shape, and the waterproof seal member is formed in such a manner that an outer diameter in the axial direction is smaller than a dimension in the axial direction of an end face of the sensor housing from which the circuit board module projects. ### Claim 2 (depends on 1) The torque detection device according to claim 1, wherein the first magnetic circuit part includes a first yoke member including a plurality of first tooth parts arranged in the circumferential direction so as to surround the multipolar magnet and a first magnetism collecting member disposed close to the first yoke member so as to be magnetically coupled to the first yoke member, the second magnetic circuit part includes a second yoke member including a plurality of second tooth parts arranged in the circumferential direction so as to surround the multipolar magnet and a second magnetism collecting member disposed close to the second yoke member so as to be magnetically coupled to the second yoke member, the second magnetism collecting member being opposed to the first magnetism collecting member in the axial direction, and the plurality of magnetic sensors are disposed in a magnetic gap formed between the first magnetism collecting member and the second magnetism collecting member. ### Claim 3 (depends on 1) The torque detection device according to claim 1, wherein the circuit board module includes: a base part that is formed in a columnar shape and coupled to the sensor housing; and a sensor mounting part that is formed in a plate-like shape and projects in the arrangement direction from the base part, the plurality of circuit elements are covered with the covering member and disposed on the sensor mounting part, and the waterproof seal member is disposed on a coupling part between the base part and the sensor housing. ### Claim 4 (depends on 1) The torque detection device according to claim 1, wherein the sensor housing includes a flange part extending in a flange extending direction from the other end side toward the one end side in the width direction of the circuit board module, the flange part includes a fixing hole penetrating the flange part in a direction perpendicular to the flange extending direction and the axial direction, and the fixing hole overlaps the first magnetic circuit part, the second magnetic circuit part, or the multipolar magnet when viewed in the arrangement direction. ### Claim 5 (depends on 1) The torque detection device according to claim 1, wherein the circuit board module is formed in such a manner that a dimension in the width direction of the circuit board module in the coupling part between the sensor housing and the circuit board module is smaller than a projecting dimension of the circuit board module from the sensor housing. ### Claim 6 A sensor module mounted on a wall member constituting a casing in an electric power steering apparatus to constitute a torque detection device in the electric power steering apparatus together with a multipolar magnet disposed coaxially with a torsion bar that coaxially couples a first shaft and a second shaft together on a rotation center axis, the multipolar magnet being housed inside the wall member, a first magnetic circuit part disposed on one side of the multipolar magnet in an axial direction parallel to the rotation center axis, and a second magnetic circuit part disposed on the other side of the multipolar magnet in the axial direction, the sensor module comprising: a plurality of magnetic sensors disposed between the first magnetic circuit part and the second magnetic circuit part so as to output an electric signal corresponding to a magnetic flux density in a magnetic circuit formed by the first magnetic circuit part and the second magnetic circuit part, the plurality of magnetic sensors being arranged in an arrangement direction included in a plane intersecting the axial direction; a circuit board module including the plurality of magnetic sensors mounted on the circuit board module and facing the magnetic circuit on one end side in a width direction, the width direction being included in the plane and intersecting the arrangement direction; and a sensor housing coupled to one end side in the arrangement direction of the circuit board module so as to support the circuit board module on the one end side in the arrangement direction of the circuit board module, wherein the circuit board module has a waterproof structure that covers a plurality of circuit elements including the plurality of magnetic sensors and a circuit board on which the plurality of circuit elements are mounted with a waterproof covering member, a waterproof seal member is disposed on a coupling part between the sensor housing and the circuit board module, the waterproof seal member is formed in a ring-like shape, and the waterproof seal member is formed in such a manner that an outer diameter in the axial direction is smaller than a dimension in the axial direction of an end face of the sensor housing from which the circuit board module projects. ### Claim 7 A sensor module mounted on a wall member constituting a casing in an electric power steering apparatus to constitute a torque detection device in the electric power steering apparatus together with a multipolar magnet disposed coaxially with a torsion bar that coaxially couples a first shaft and a second shaft together on a rotation center axis, the multipolar magnet being housed inside the wall member, a first magnetic circuit part disposed on one side of the multipolar magnet in an axial direction parallel to the rotation center axis, and a second magnetic circuit part disposed on the other side of the multipolar magnet in the axial direction, the sensor module comprising: a magnetic sensor disposed between the first magnetic circuit part and the second magnetic circuit part so as to output an electric signal corresponding to a magnetic flux density in a magnetic circuit formed by the first magnetic circuit part and the second magnetic circuit part; a circuit board module projecting in a projecting direction included in a plane intersecting the axial direction, the circuit board module including the magnetic sensor mounted on the circuit board module and facing the magnetic circuit on one end side in a width direction, the width direction being included in the plane and intersecting the projecting direction; and a sensor housing coupled to one end side in the projecting direction of the circuit board module so as to support the circuit board module on the one end side in the projecting direction of the circuit board module, wherein the circuit board module has a waterproof structure that covers a plurality of circuit elements including the magnetic sensor and a circuit board on which the plurality of circuit elements are mounted with a waterproof covering member, a waterproof seal member is disposed on a coupling part between the sensor housing and the circuit board module, the waterproof seal member is formed in a ring-like shape, and the waterproof seal member is formed in such a manner that an outer diameter in the axial direction is smaller than a dimension in the axial direction of an end face of the sensor housing from which the circuit board module projects. ### Claim 8 The sensor module according to 7, wherein the circuit board module is formed in such a manner that an edge on the one end side in the width direction is more separated from the rotation center axis with distance from the sensor housing, and the magnetic sensor is disposed near the edge. ### Claim 9 A torque detection device configured to output an electric signal corresponding to a torsional torque generated in a torsion bar that coaxially couples a first shaft and a second shaft together on a rotation center axis, the torsional torque being caused by relative rotation between the first shaft and the second shaft about the rotation center axis, the torque detection device comprising: a first magnetic circuit part disposed on one side of a multipolar magnet in an axial direction parallel to the rotation center axis, the multipolar magnet being configured in such a manner that magnetic poles are alternately inverted in a circumferential direction surrounding the rotation center axis and being disposed coaxially with the torsion bar so as to rotate about the rotation center axis along with the relative rotation; a second magnetic circuit part disposed on the other side of the multipolar magnet in the axial direction; one or more magnetic sensors disposed between the first magnetic circuit part and the second magnetic circuit part so as to output an electric signal corresponding to a magnetic flux density in a magnetic circuit formed by the first magnetic circuit part and the second magnetic circuit part; and a circuit board module projecting in a projecting direction included in a plane intersecting the axial direction, the circuit board module including the magnetic sensors mounted on the circuit board module and facing the magnetic circuit, wherein the circuit board module has a waterproof structure that covers a plurality of circuit elements including the magnetic sensors and a circuit board on which the plurality of circuit elements are mounted with a waterproof covering member, wherein a sensor housing is coupled to one end side in the projecting direction of the circuit board module so as to support the circuit board module on the one end side in the projecting direction of the circuit board module, a coupling part between the sensor housing and the circuit board module has a waterproof seal structure, an O-ring is attached so as to surround the coupling part between the sensor housing and the circuit board module, and the O-ring is pressed in a ring radial direction intersecting the projecting direction between the coupling part and the wall member to liquid-tightly join the sensor housing to the wall member. ### Claim 10 (depends on 9) The torque detection device according to claim 9, wherein the first magnetic circuit part includes a first yoke member including a plurality of first tooth parts arranged in the circumferential direction so as to surround the multipolar magnet and a first magnetism collecting member disposed close to the first yoke member so as to be magnetically coupled to the first yoke member, the second magnetic circuit part includes a second yoke member including a plurality of second tooth parts arranged in the circumferential direction so as to surround the multipolar magnet and a second magnetism collecting member disposed close to the second yoke member so as to be magnetically coupled to the second yoke member, the second magnetism collecting member being opposed to the first magnetism collecting member in the axial direction, the magnetic sensors are disposed in a magnetic gap formed between the first magnetism collecting member and the second magnetism collecting member, and the covering member covers the first magnetism collecting member and the second magnetism collecting member. ### Claim 11 (depends on 9) The torque detection device according to claim 9, wherein the covering member covers an object to be covered so that the object to be covered is not exposed. ### Claim 12 (depends on 9) The torque detection device according to claim 9, wherein the sensor housing includes a waterproof connector for electrical connection with an external device. ### Claim 13 (depends on 9) The torque detection device according to claim 9, wherein the sensor housing is configured to be liquid-tightly joined to a wall member constituting a casing in an electric power steering apparatus. ### Claim 14 (depends on 9) The torque detection device according to claim 9, wherein the circuit board module includes the magnetic sensors mounted on the circuit board module on one end side in a width direction, the width direction being included in the plane and intersecting the projecting direction. ### Claim 15 (depends on 9) The torque detection device according to claim 9, wherein a plurality of the magnetic sensors are arranged in the projecting direction.