Torque steering angle sensor

Patent metadata

Field	Value
Publication number	US-2016138983-A1
Application number	US-201514924359-A
Country	US
Kind code	A1
Filing date	Oct 27, 2015
Priority date	Nov 19, 2014
Publication date	May 19, 2016
Grant date	—

Abstract

A torque steering angle sensor is provided. The sensor includes a ring magnet with magnetic poles, magnetic path forming members to vary in location relative to the magnetic poles depending on torsion of a torsion bar, one pair of magnetic flux collecting rings for the magnetic path forming members, a first detecting element to detect a magnetic field between the flux collecting rings, a second detecting element to receive a magnetic field from the ring magnet, a slide magnet for producing a magnetic field in a different direction from that of the magnetic field of the ring magnet in the second detecting element, and a sliding mechanism to move the slide magnet toward or apart from the second detecting element with rotation of a rotary member of an electrically assisted power steering device. The second detecting element detects the magnetic fields received from the ring magnet and the slide magnet.

First claim

What is claimed is:

1 . A torque steering angle sensor, which is arranged on a coupling portion for a first rotary member and a second rotary member of an electrically assisted power steering device to be coupled together by a torsion bar having a torsional angle depending on a steering torque of a steering wheel, and which is configured to detect a steering angle and the steering torque of the steering wheel, comprising:
an annular ring magnet provided with a plurality of magnetic poles having different polarities in a circumferential direction around a rotational axis of the first rotary member and the second rotary member, the annular ring magnet being configured to rotate together with the first rotary member; a plurality of magnetic path forming members to form magnetic paths for a magnetic flux of the ring magnet, the magnetic path forming members being configured to vary in location relative to the plurality of magnetic poles of the ring magnet, depending on torsion of the torsion bar; one pair of magnetic flux collecting rings to collect the magnetic flux of the plurality of magnetic path forming members; a first magnetic field detecting element to detect a magnetic field strength between the one pair of magnetic flux collecting rings; a non-rotary member for being not rotated by rotation of the first rotary member; a second magnetic field detecting element fixed to the non-rotary member, and located in such a manner as to receive a magnetic field from the ring magnet; a slide magnet for producing a magnetic field in a different direction from that of the magnetic field of the ring magnet in the second magnetic field detecting element; and a sliding mechanism to move the slide magnet toward or apart from the second magnetic field detecting element with the rotation of the first rotary member, wherein the second magnetic field detecting element is configured to be able to detect a magnetic field strength received from the ring magnet, and a magnetic field strength received from the slide magnet.

2 . The torque steering angle sensor according to claim 1 , wherein the second magnetic field detecting element is disposed opposite an outer circumferential surface of the ring magnet, so as to be able to detect magnetic field strengths in circumferential and radial directions of the ring magnet.

3 . The torque steering angle sensor according to claim 1 , wherein the sliding mechanism is configured to move the slide magnet parallel to the rotational axis.

4 . The torque steering angle sensor according to claim 3 , wherein the sliding mechanism includes:
a supporting member for supporting the slide magnet; an annular member configured to rotate together with the first rotary member, and including a helical meshing portion formed around an outer circumferential surface in such a manner as to mesh with the supporting member; and a guiding member fixed to the non-rotary member so as to guide the supporting member parallel to the rotational axis.

5 . The torque steering angle sensor according to claim 1 , wherein the ring magnet is located apart from the one pair of magnetic flux collecting rings in a rotational axis direction, and
the plurality of magnetic path forming members each include a respective opposite piece, which is located opposite and parallel to an axial end face of the ring magnet, a respective transmitting or receiving portion to transmit or receive the magnetic flux to or from one of the one pair of magnetic flux collecting rings, and a respective transferring portion to transfer the magnetic flux between the respective opposite piece and the respective transmitting or receiving portion.

6 . The torque steering angle sensor according to claim 5 , wherein the one pair of magnetic flux collecting rings each include a respective annular portion, which is disposed coaxially with the ring magnet to transmit or receive the magnetic flux to or from the respective transmitting or receiving portions of the magnetic path forming members, and a respective opposite portion, which is located opposite the first magnetic field detecting element,
wherein the annular portions are in an annular plate shape whose radial width is larger than its axial thickness, wherein the transmitting or receiving portions include a tip formed in a circular arc shape having a curvature having an inner radius of the annular portions, extend in a radial direction of the annular portions, and are in a plate shape having a thickness in an axial direction of the annular portions.

7 . The torque steering angle sensor according to claim 5 , wherein the one pair of magnetic flux collecting rings each include a respective annular portion, which is disposed coaxially with the ring magnet to transmit or receive the magnetic flux to or from the respective transmitting or receiving portions of the magnetic path forming members, and a respective opposite portion, which is located opposite the first magnetic field detecting element,
wherein the annular portions are in a circular cylindrical shape whose axial width is larger than its radial thickness, wherein the transmitting or receiving portions are in a plate shape radially opposite respective inner circumferential surfaces of the annular portions.

8 . The torque steering angle sensor according to claim 6 , wherein the second magnetic field detecting element and the slide magnet are located closer to the rotational axis than respective radial outer edges of the respective annular portions of the one pair of magnetic flux collecting rings.

9 . The torque steering angle sensor according to claim 1 , wherein the first magnetic field detecting element and the second magnetic field detecting element are located with the rotational axis therebetween.

10 . The torque steering angle sensor according to claim 1 , wherein the ring magnet includes 4 or more magnetic poles.

Assignees

• Hitachi Metals Ltd

Inventors

• Ikeda Yukio

Classifications

• B62D6/10 Primary

  characterised by means for sensing {or determining} torque · CPC title

• B62D15/0215

  by measuring on the steering column · CPC title

• G01L3/101 Primary

  involving magnetic or electromagnetic means · CPC title