JP2016142713A - Torque/steering angle sensor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress an increase in the number of components and an increase in assembly man-hours in a torque/steering angle sensor which makes it possible to detect a steering torque and a steering angle.SOLUTION: A torque/steering angle sensor 2 comprises: a ring magnet 31 that rotates together with a first rotary member 111 and in which a plurality of magnetic poles are formed in the circumferential direction; first and second magnetic yokes 41, 42 whose relative physical relationships with the magnetic poles of the ring magnet 31 changes in accordance with the torsion of a torsion bar 113; first and second annular magnetic flux collection ring 51, 52, each magnetically coupled to the first and second magnetic yokes 41, 42; a first magnetism detection element 61 for detecting the intensity of a magnetic field between the first and second magnetic flux collection ring 51, 52; a second magnetism detection element 62 for detecting the intensity of a magnetic field that changes with the rotation of the ring magnet 31; and a circuit board 63 on the packaging surface 63a of which the first magnetism detection element 61 and second magnetism detection element 62 are packaged, the circuit board 63 being disposed in such a way that the packaging surface 63a is along a direction parallel to an axis of rotation O.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a torque steering angle sensor capable of detecting a steering torque and a steering angle of a steering wheel of a vehicle.

  Conventionally, an electric power steering device for a vehicle is provided with a torque sensor capable of detecting a steering torque. Such a torque sensor is configured to magnetically detect the torsion amount of the torsion bar that twists according to the steering torque (see, for example, Patent Documents 1 and 2).

  The torque sensor described in Patent Document 1 includes a torsion bar that coaxially connects an input shaft and an output shaft, a ring-shaped magnet that is attached to the end of the input shaft, and a pair of attachments that are attached to the end of the output shaft. The magnetic yoke includes a pair of magnetic flux collecting rings arranged close to the outer periphery of the magnetic yoke, and a magnetic sensor for detecting a magnetic flux density generated in the magnetic flux collecting ring. The magnetic sensor is connected to a control board of a control unit that controls the electric motor of the electric power steering apparatus. The control board is disposed in the housing so as to be orthogonal to the input shaft, and the input shaft passes through the central portion thereof.

  The torque sensor described in Patent Document 2 is configured to be able to detect a steering angle in addition to a steering torque, and a torsion bar that connects an input shaft and an output shaft of the steering shaft, and an input shaft of the steering shaft. A fixed sensor yoke assembly; a magnetic flux collecting yoke assembly that collects magnetic flux of the sensor yoke assembly; an annular permanent magnet that rotates together with the output shaft of the steering shaft; and a first magnetic flux collecting yoke component that constitutes the magnetic flux collecting yoke assembly It has the 1st magnetic detector arrange | positioned between 2nd magnetism collection yoke structure parts, and the 2nd magnetic detector arrange | positioned facing the outer peripheral surface of a permanent magnet. The first magnetic detector and the second magnetic detector are composed of, for example, a Hall element, an MR element, or an MI element, and are fixed in a gear cover that houses the torque sensor.

  The torque sensor described in Patent Document 2 configured as described above can detect the steering torque by changing the magnetic field intensity detected by the first magnetic detector according to the torsion angle of the torsion bar. In addition, the rotation angle between the adjacent north and south poles can be detected by changing the magnetic field intensity detected by the second magnetic detector as the permanent magnet rotates, and by accumulating the rotation angles. It is possible to calculate the steering angle.

JP 2004-101277 A JP 2010-190632 A

  The torque sensor described in Patent Document 2 is more advantageous than the torque sensor described in Patent Document 1 in that the steering angle can be detected. However, the first magnetic detector and the second magnetic detector are mounted on the substrate, respectively. When connecting, the position of the first magnetic detector and the second magnetic detector in the axial direction of the steering shaft is different. For example, the first substrate on which the first magnetic detector is mounted and the second magnetic detector are mounted. The second substrate must be juxtaposed along the axial direction of the steering shaft. For this reason, an increase in the number of parts and an increase in assembling man-hours are caused.

  In view of the above circumstances, the present invention has been made for the purpose of suppressing an increase in the number of parts and an increase in assembly man-hours in a torque steering angle sensor capable of detecting a steering torque and a steering angle.

  In order to solve the above-mentioned problems, the present invention provides an electric power steering apparatus including a first rotating member and a second rotating member connected by a torsion bar that generates a twist angle according to a steering torque of a steering wheel. A torque steering angle sensor disposed at a connection portion between the first rotating member and the second rotating member and detecting a steering angle and a steering torque of the steering wheel, wherein the first rotating member and the second rotating member A plurality of magnetic poles having different polarities are formed along a circumferential direction about a rotation axis, and an annular ring magnet that rotates together with the first rotating member, a magnetic path of magnetic flux by the ring magnet, and the torsion bar A plurality of magnetic path forming members whose relative positional relationship with the plurality of magnetic poles of the ring magnet changes according to twisting of the ring magnet, and formed in an annular shape A pair of magnetism collecting rings each having an annular portion and magnetically coupled to each of the plurality of magnetic path forming members, and a first for detecting the strength of the magnetic field between the pair of magnetism collecting rings A magnetic detection element; a second magnetic detection element for detecting a rotation angle of the first rotating member based on the intensity of a magnetic field that changes as the ring magnet rotates; and the first magnetic detection element. And a substrate on which the second magnetic detection element is mounted on a mounting surface, wherein the substrate is disposed so that the mounting surface is along a direction parallel to the rotation axis. To do.

  According to the torque steering angle sensor according to the present invention, it is possible to detect the steering torque and the steering angle by using a plurality of magnetic detection elements, while increasing the number of parts for arranging the magnetic detection elements and increasing the number of assembly steps. It becomes possible to suppress.

It is a mimetic diagram showing an electric power steering device to which a torque steering angle sensor concerning this embodiment is applied. It is an external appearance perspective view which shows a torque steering angle sensor. It is sectional drawing of the torque steering angle sensor along the rotating shaft line of a steering shaft. (A) And (b) is a perspective view which shows a one part component of a torque steering angle sensor. It is a disassembled perspective view for demonstrating the structure of a torque steering angle sensor. It is a top view which shows a one part component of a torque steering angle sensor, (a) is a top view, (b) is a front view.

[Embodiment]
Hereinafter, the present embodiment will be described with reference to FIGS.

  FIG. 1 is a schematic diagram showing an electric power steering apparatus 1 to which a torque steering angle sensor according to the present embodiment is applied.

  The electric power steering apparatus 1 includes a steering shaft 11 connected to a steering wheel 10, an intermediate shaft (intermediate shaft) 13 connected to the steering shaft 11 via a universal joint 12, and an intermediate shaft 13. The pinion shaft 15 connected via the universal joint 14, the rack shaft 16 formed with the rack teeth 160 that mesh with the pinion teeth 150 of the pinion shaft 15, and the steering applied to the steering shaft 11 during the steering operation of the steering wheel 10. A steering assist mechanism 17 that generates a steering assist force according to torque and a torque steering angle sensor 2 that detects the steering angle and steering torque of the steering wheel 10 are provided.

  The rack shaft 16 is supported by a rack housing (not shown) and moves in the vehicle width direction according to the steering operation of the steering wheel 10. The left and right front wheels 19L and 19R, which are steered wheels, and the rack shaft 16 are connected by left and right tie rods 18L and 18R. The rack shaft 16 and the pinion shaft 15 constitute a rack and pinion type steering mechanism.

  In the present embodiment, the steering assist mechanism 17 is a rack assist type steering assist mechanism that applies a steering assist force to the rack shaft 16, and the rotational force of the electric motor 170 is converted into a linear moving force by, for example, a ball screw mechanism. Then, it is applied to the rack shaft 16 as a steering assist force. However, the steering assist mechanism 17 is provided on a steering column that supports the steering shaft 11, and is a column assist type that decelerates the rotational force of the electric motor 170 by, for example, a worm gear mechanism and applies the steering assist force to the steering shaft 11. It may be.

  The steering assist mechanism 17 is supplied with a motor current from the control device 20 and generates a steering assist force according to the motor current. The control device 20 calculates a steering torque and a steering angle based on an output signal of the torque steering angle sensor 2, and a steering to be applied based on a calculation result of the torque / steering angle calculation unit 21. A steering assist force calculator 22 that calculates an assist force, and a motor drive circuit 23 that outputs a motor current corresponding to the steering assist force calculated by the steering assist force calculator 22 and drives the electric motor 170 of the steering assist mechanism 17. And have.

  The steering assist force calculating unit 22 increases the steering assist force applied to the steering mechanism by the steering assist mechanism 17 as the steering torque increases and as the steering speed calculated based on the temporal change in the steering angle increases. The operation is performed as follows. The steering angle calculated by the torque / steering angle calculation unit 21 is also used for control in, for example, a vehicle side slip prevention device (ESC: Electronic Stability Control).

  The steering shaft 11 includes a first rotating member 111 on the steering wheel 10 side and a second rotating member 112 on the intermediate shaft 13 side. The first rotating member 111 and the second rotating member 112 will be described later. It is connected by a torsion bar. The torque steering angle sensor 2 is disposed at a connecting portion between the first rotating member 111 and the second rotating member 112. In the present embodiment, the torque steering angle sensor 2 is disposed on the steering shaft 11. However, the present invention is not limited to this, and the torque steering angle sensor 2 may be disposed on the pinion shaft 15, for example.

(Configuration of torque steering angle sensor)
Next, the configuration of the torque steering angle sensor 2 will be described with reference to FIGS. In the following description, for convenience of explanation, the steering wheel 10 side in the axial direction of the steering shaft 11 is described as “up” and the opposite side (intermediate shaft 13 side) is described as “down”. Alternatively, “down” does not limit the vertical direction in the usage state of the electric power steering apparatus 1.

  FIG. 2 is an external perspective view showing the torque steering angle sensor 2. FIG. 3 is a cross-sectional view of the torque steering angle sensor 2 along the rotation axis O of the steering shaft 11. FIGS. 4A and 4B are perspective views showing some components of the torque steering angle sensor 2. FIG. 5 is an exploded perspective view for explaining the configuration of the torque steering angle sensor 2. 6A and 6B are plan views showing some components of the torque steering angle sensor 2, wherein FIG. 6A is a top view and FIG. 6B is a front view.

  The first rotating member 111 and the second rotating member 112 of the steering shaft 11 share the rotation axis O and rotate together with the steering wheel 10. As shown in FIG. 3, the first rotating member 111 and the second rotating member 112 are connected by a torsion bar 113 that generates a twist angle according to the steering torque of the steering wheel 10. One end of the torsion bar 113 in the axial direction is coupled to the first rotating member 111 so as not to be relatively rotatable, and the other end is coupled to the second rotating member 112 so as not to be relatively rotatable. In the present embodiment, the upper end portion of the torsion bar 113 is fixed to the first rotating member 111 by the bolt 114, and the lower end portion is fixed to the second rotating member 112 by the bolt 115.

  The torque steering angle sensor 2 is accommodated in a column housing 110 that holds the steering shaft 11 so that the tilt can be adjusted. In FIG. 3, the column housing 110 is illustrated by a two-dot chain line.

  The torque steering angle sensor 2 includes an annular ring magnet 31 that rotates together with the first rotating member 111, a magnet holding member 116 that holds the ring magnet 31, and a plurality of magnetic path formations that form a magnetic path of magnetic flux by the ring magnet 31. The first magnetic yoke 41 and the second magnetic yoke 42 as members, the yoke holding member 40 that holds the first magnetic yoke 41 and the second magnetic yoke 42, and the yoke holding member 40 are used as the second rotating member 112. Generated by the ring-shaped magnet 31 and the first and second magnetic flux collecting rings 51 and 52 for collecting the magnetic flux of the first magnetic yoke 41 and the second magnetic yoke 42. And a magnetic detection unit 6 capable of detecting the intensity of the magnetic field.

  The magnetic detection unit 6 includes a first magnetic detection element 61 for detecting the strength of the magnetic field between the first and second magnetic flux collecting rings 51 and 52, and a magnetic field that changes as the ring magnet 31 rotates. Based on the strength, the second magnetic detection element 62 for detecting the rotation angle of the first rotation member 111, the first magnetic detection element 61, and the second magnetic detection element 62 are mounted on the mounting surface 63a. And a substrate 63.

  The board 63 is a printed board in which, for example, glass epoxy resin is used as a base material, and a wiring pattern and electrodes made of copper foil are formed on the surface of the base material. In the present embodiment, both the first magnetic detection element 61 and the second magnetic detection element 62 are mounted on the mounting surface 63a side which is one main surface of the substrate 63, and components are not mounted on the non-mounting surface 63b which is the back side. Is not implemented. The first magnetic detection element 61 and the second magnetic detection element 62 are surface-mounted on the mounting surface 63 a of the substrate 63.

  In the present embodiment, the first magnetic detection element 61 and the second magnetic detection element 62 are Hall ICs including Hall elements that convert the intensity of the magnetic field into electric signals using the Hall effect. Instead of the Hall element, other elements such as an MR (Magneto Resistance) element, a GIG (Granular In Gap) element, and a GMR (Giant Magneto-resistive) element may be used. The first magnetic detection element 61 and the second magnetic detection element 62 can detect the intensity of a bidirectional magnetic field perpendicular to the mounting surface 63 a of the substrate 63.

  The ring magnet 31 is fixed to the lower end portion of the magnet holding member 116 by, for example, adhesion. The magnet holding member 116 has a cylindrical shape in which the first rotating member 111 is inserted in the center thereof, and an upper end portion thereof is fixed to the first rotating member 111 by a bolt 114. Further, the magnet holding member 116 has a lower end formed to have an outer diameter smaller than that of the upper end, and the ring magnet 31 is fitted to the outer peripheral surface of the lower end.

  As shown in FIGS. 4 and 5, a plurality of magnetic poles having different magnetism are formed in the ring magnet 31 along the circumferential direction around the rotation axis O. In the present embodiment, four magnetic poles including two N poles 311 and two S poles 312 are formed on the ring magnet 31.

  As shown in FIGS. 2 to 4, the ring magnet 31 is disposed at a position shifted from the first and second magnetism collecting rings 51 and 52 in the direction of the rotation axis O. More specifically, the second magnetism collecting ring 52 is arranged above the first magnetism collecting ring 51, and the ring magnet 31 is arranged further above the second magnetism collecting ring 52. The first magnetic yoke 41 magnetically couples the ring magnet 31 and the first magnetism collecting ring 51, and the second magnetic yoke 42 magnetically couples the ring magnet 31 and the second magnetism collecting ring 52. To join.

  As described above, the ring magnet 31 rotates together with the first rotating member 111, and the first magnetic yoke 41 and the second magnetic yoke 42 are connected to the second rotating member 112 via the yoke holding member 40 and the support member 117. Since it is fixed, when a steering torque is applied to the steering shaft 11 by the steering operation of the steering wheel 10 by the driver of the vehicle, the torsion bar 113 is twisted, and the magnetic poles of the ring magnet 31 and the first magnet are changed according to the amount of twist. The relative positional relationship between the first magnetic yoke 41 and the second magnetic yoke 42 changes.

  In FIG. 4, the ring magnet 31, the first and second magnetic yokes 41 and 42, the first and second magnetic flux collecting rings 51 and 52, and the magnetic detection unit 6 when the torsion bar 113 is not twisted are shown. The relative positional relationship is shown in (a), and the relative positional relationship when the torsion bar 113 is twisted by the steering torque is shown in (b).

  In the present embodiment, the torque steering angle sensor 2 is provided with two first magnetic yokes 41 and two second magnetic yokes 42. In a state where the torsion bar 113 is not twisted, the two first magnetic yokes 41 and the two second magnetic yokes 42 face the boundary portion between the N pole 311 and the S pole 312 of the ring magnet 31. .

  As shown in FIG. 5, the first magnetic yoke 41 includes an opposing piece 411 facing in parallel with the axial end surface of the ring magnet 31, and a transfer unit 413 that transfers magnetic flux between the first magnetism collecting ring 51, And the transmission part 412 which transmits a magnetic flux between the opposing piece 411 and the delivery part 413 is provided. The facing piece 411 has a flat plate shape having a facing surface 411a facing the lower surface of the ring magnet 31 (the axial end surfaces on the first and second magnetism collecting rings 51 and 52 side). The magnet 31 extends outward in the radial direction. The delivery part 413 extends from the lower end part of the transmission part 412 toward the radially outer side of the ring magnet 31. The transmission unit 412 has a flat plate shape arranged in parallel with the rotation axis O.

  The second magnetic yoke 42 includes a counter piece 421 facing in parallel with the axial end surface of the ring magnet 31, a transfer part 423 for transferring magnetic flux between the second magnetism collecting ring 52, and a counter piece 421 and a transfer part. A transmission portion 422 that transmits magnetic flux to and from 423 is provided. The opposing piece 421 has a flat plate shape having an opposing surface 421a that opposes the lower surface of the ring magnet 31 (the axial end surfaces on the first and second magnetism collecting rings 51 and 52 side). The magnet 31 extends outward in the radial direction. The delivery portion 423 extends from the lower end portion of the transmission portion 422 toward the radially outer side of the ring magnet 31. The transmission unit 422 has a flat plate shape arranged in parallel with the rotation axis O.

  The length of the transmission part 422 of the second magnetic yoke 42 in the direction parallel to the rotation axis O is shorter than the transmission part 412 of the first magnetic yoke 41. This difference in length is based on the difference in the vertical position between the annular portion 511 of the first magnetic flux collecting ring 51 and the annular portion 521 of the second magnetic flux collecting ring 52 described below.

  As shown in FIGS. 5 and 6, the first magnetism collecting ring 51 is arranged on the same axis as the ring magnet 31, and transfers the magnetic flux to and from the transfer portion 413 of the first magnetic yoke 41. And a side plate portion 513 facing the mounting surface 63a of the substrate 63, and a connecting portion 512 for connecting the annular portion 511 and the side plate portion 513. The connecting portion 512 includes a radially extending portion 512a that extends radially outward from an outer peripheral surface of a portion of the annular portion 511 in the circumferential direction, and an axially extending portion that extends upward from the radially extending portion 512a. 512b. The side plate portion 513 is a flat plate shape that extends from the upper end portion of the axially extending portion 512b toward the radially outer side of the annular portion 511 and has a thickness in a direction facing the mounting surface 63a of the substrate 63.

  The second magnetism collecting ring 52 is arranged coaxially with the ring magnet 31 and faces the annular portion 521 that transfers magnetic flux to and from the transfer portion 423 of the second magnetic yoke 42, and the non-mounting surface 63 b of the substrate 63. And a connecting portion 522 that connects the annular portion 521 and the side plate portion 523. The connecting portion 522 includes a radially extending portion 522a that extends radially outward from an outer peripheral surface of a portion of the annular portion 521 in the circumferential direction, and an axially extending portion that extends downward from the radially extending portion 522a. 522b. The side plate portion 523 is a flat plate shape that extends from the lower end portion of the axially extending portion 522b toward the radially outer side of the annular portion 521 and has a thickness in a direction facing the non-mounting surface 63b of the substrate 63.

  The annular portion 511 of the first magnetism collecting ring 51 and the annular portion 521 of the second magnetism collecting ring 52 have the same inner diameter and outer diameter, and are arranged in parallel facing each other in the vertical direction. Further, both the annular portions 511 and 521 are both formed in an annular shape centering on the rotation axis O, and have a flat plate shape whose radial width is larger than the axial thickness.

  The transfer portion 413 of the first magnetic yoke 41 has a tip portion formed in an arc shape having a curvature corresponding to the inner diameter of the annular portion 511 of the first magnetic flux collecting ring 51 and extends in the radial direction of the annular portion 511. The plate portion has a thickness in the axial direction of the annular portion 511. The front end surface 413 a of the transfer portion 413 in the first magnetic yoke 41 is formed to be curved so as to face the inner peripheral surface 511 a of the annular portion 511 of the first magnetic flux collecting ring 51.

  Similarly, the transfer portion 423 of the second magnetic yoke 42 has an end portion formed in an arc shape having a curvature corresponding to the inner diameter of the annular portion 521 of the second magnetism collecting ring 52, and in the radial direction of the annular portion 521. It has a plate shape that extends and has a thickness in the axial direction of the annular portion 521. The tip end surface 423 a of the transfer portion 423 in the second magnetic yoke 42 is formed to be curved so as to face the inner peripheral surface 521 a of the annular portion 521 of the second magnetism collecting ring 52 in parallel.

  The first magnetism collecting ring 51 is magnetically coupled to the first magnetic yoke 41, and the second magnetism collecting ring 52 is magnetically coupled to the second magnetic yoke 42. Then, the first and second magnetism collecting rings 51 and 52 rotate together with the second rotating member 112 while maintaining this magnetic coupling state. The distance between the front end surface 413a of the transfer portion 413 of the first magnetic yoke 41 and the inner peripheral surface 511a of the annular portion 511 of the first magnetism collecting ring 51 is constant, and the transfer portion 423 of the second magnetic yoke 42 is fixed. The distance between the tip surface 423a and the inner peripheral surface 521a of the annular portion 521 of the second magnetism collecting ring 52 is constant. Thereby, even if the second rotating member 112 rotates, the magnetic resistance between the first magnetic yoke 41 and the first magnetic flux collecting ring 51, and the second magnetic yoke 42 and the second magnetic flux collecting ring 52. The magnetoresistance between the two is kept constant.

  As shown in FIGS. 6A and 6B, the side plate portions 513 and 523 of the first and second magnetism collecting rings 51 and 52 are positioned outside the annular portions 511 and 521, respectively, and the annular portion 511. , 521 in the circumferential direction. Further, the side plate portions 513, 523 of the first and second magnetism collecting rings 51, 52 are arranged at positions farther from the rotation axis O than the outer peripheral surface of the ring magnet 31.

  The first magnetic detection element 61 is disposed between the pair of side plate portions 513 and 523 of the first and second magnetism collecting rings 51 and 52. The second magnetic detection element 62 faces the outer peripheral surface of the ring magnet 31. Further, the substrate 63 is arranged so that the mounting surface 63a is along the direction parallel to the rotation axis O, and the second mounting region 632 where the second magnetic detection element 62 is mounted is the first magnetic detection element 61. Is provided so as to protrude from the first mounting region 631 where the is mounted on the rotation axis O side. In the present embodiment, the mounting surface 63a of the substrate 63 is perpendicular to the circumferential direction about the rotation axis O.

  As shown in FIG. 3, the substrate 63 is fixed inside the column housing 110. When the ring magnet 31 rotates together with the first rotating member 111, the N pole 311 and the S pole 312 of the ring magnet 31 alternately face the second magnetic detection element 62, and the second magnetic detection element 62 responds to this rotation. The direction and strength of the detected magnetic field changes. The rotation angle of the first rotating member 111 can be detected based on the output signal of the second magnetic detection element 62.

  The first and second magnetic detection elements 61 and 62 are electrically connected to the control device 20 (see FIG. 1) via a signal line (not shown) connected to the substrate 63, and the first and second magnetic detection elements are connected. Output signals of the detection elements 61 and 62 are sent to the torque / steering angle calculation unit 21 of the control device 20. The torque / steering angle calculator 21 calculates the steering torque and the steering angle based on the output signals of the first and second magnetic detection elements 61 and 62.

(Operation of torque steering angle sensor)
Detection of the steering torque in the torque steering angle sensor 2 is performed by the first magnetic detection element 61, and detection of the steering angle is performed by the second magnetic detection element 62. When the steering torque is not applied to the steering shaft 11, as shown in FIG. 4A, the opposing pieces 411 and 421 of the first and second magnetic yokes 41 and 42 in the circumferential direction of the ring magnet 31 are used. The central portion faces the boundary between the N pole 311 and the S pole 312 of the ring magnet 31. In this state, the intensity of the magnetic field detected by the first magnetic detection element 61 is substantially zero.

  On the other hand, when the steering torque is applied to the steering shaft 11 and the torsion bar 113 is twisted, the twist causes the ring magnet 31 and the first and second magnetic yokes 41 and 42 to rotate relative to each other, and the magnetic poles of the ring magnet 31 are rotated. The opposing positions of the opposing pieces 411 and 421 of the first and second magnetic yokes 41 and 42 with respect to the (N pole 311 and S pole 312) are shifted in the circumferential direction of the ring magnet 31.

  For example, when the ring magnet 31 rotates a predetermined angle (for example, 5 °) in the direction of arrow A in FIG. 4B with respect to the first and second magnetic yokes 41, 42, the opposing pieces 411 of the first magnetic yoke 41 and Of the magnetic poles of the ring magnet 31 facing in the axial direction, the ratio of the N pole 311 is higher than that of the S pole 312. In addition, the ratio of the S pole 312 in the magnetic poles of the ring magnet 31 facing the opposing piece 421 of the second magnetic yoke 42 in the axial direction is higher than that of the N pole 311. As a result, part of the magnetic flux emitted from the N pole 311 passes through the first magnetic detection element 61 via the first magnetic yoke 41 and the first magnetic flux collecting ring 51, and the second magnetic flux collecting ring 52 and It returns to the S pole 312 through the second magnetic yoke 42.

  On the other hand, when the ring magnet 31 rotates in the direction opposite to the arrow A direction with respect to the first and second magnetic yokes 41 and 42, it opposes the facing piece 411 of the first magnetic yoke 41 in the axial direction. Of the magnetic poles of the ring magnet 31, the proportion of the S pole 312 is higher than that of the N pole 311. Of the magnetic poles of the ring magnet 31 facing the opposing piece 421 of the second magnetic yoke 42 in the axial direction, the N pole 311. Is higher than that of the S pole 312. Thereby, the magnetic flux passes through the first magnetic detection element 61 in the direction opposite to the above.

  The intensity (absolute value) of the magnetic field detected by the first magnetic detection element 61 increases as the torsion amount of the torsion bar 113 increases. Thus, the strength of the magnetic field detected by the first magnetic detection element 61 changes according to the twist of the torsion bar 113, and the direction of the magnetic field switches according to the twist direction of the torsion bar 113.

(Operation and effect of the embodiment)
According to the first embodiment described above, the following operations and effects can be obtained.

(1) The ring magnet 31, the first magnetic yoke 41, and the second magnetic yoke 42 rotate relative to each other by the torsion of the torsion bar 113, and are detected by the first magnetic detection element 61 according to the angle of the relative rotation. The steering torque can be detected by changing the intensity of the magnetic field. Further, the steering angle of the steering wheel 10 can be obtained by detecting the strength of the magnetic field received by the second magnetism detecting element 62 from the ring magnet 31. Furthermore, since the first and second magnetic detection elements 61 and 62 are mounted on one substrate 63 arranged along a direction parallel to the rotation axis O, the first and second magnetic detection elements 61 and 62 are mounted. The arrangement of the detection elements 61 and 62 is facilitated. Thereby, it is possible to suppress an increase in the number of parts of the torque steering angle sensor 2 and an increase in the number of assembling steps.

(2) Since the first magnetic detection element 61 is disposed between the pair of side plate portions 513 and 523 facing each other along the circumferential direction of the first and second magnetism collecting rings 51 and 52, the side plate A uniform magnetic field is generated between the parts 513 and 523, and the strength of the magnetic field between the first magnetism collecting ring 51 and the second magnetism collecting ring 52 can be detected with high accuracy.

(3) In the substrate 63, the second mounting region 632 on which the second magnetic detection element 62 is mounted is closer to the rotation axis O side than the first mounting region 631 on which the first magnetic detection element 61 is mounted. Since the second magnetic detection element 62 is provided so as to protrude, the second magnetic detection element 62 can be disposed close to the ring magnet 31, and the magnetic field detection accuracy by the second magnetic detection element 62 can be increased.

(4) Since the ring magnet 31 has four magnetic poles, the rotational accuracy of the steering angle is higher than in the case where the magnetic poles have two poles. That is, the strength of the magnetic field detected by the second magnetic detection element 62 changes from a positive maximum value to a negative maximum value in a narrow angle range as compared with the case where the number of magnetic poles is two. Resolution can be increased. The number of magnetic poles of the ring magnet 31 is not limited to 4, and may be 6 or 8, for example. That is, by setting the number of magnetic poles of the ring magnet 31 to 4 or more, the steering angle can be obtained with high accuracy.

(Summary of embodiment)
Next, the technical idea grasped from the embodiment described above will be described with reference to the reference numerals in the embodiment. However, each reference numeral in the following description does not limit the constituent elements in the claims to members or the like specifically shown in the embodiment.

[1] Electric power steering apparatus having a first rotating member (111) and a second rotating member (112) connected by a torsion bar (113) that generates a twist angle according to the steering torque of the steering wheel (10) ( 1 is a torque steering angle sensor (2) that is disposed at a connecting portion between the first rotating member (111) and the second rotating member (112) and detects a steering angle and a steering torque of the steering wheel (10). A plurality of magnetic poles (311 and 312) having different polarities are formed along a circumferential direction around a rotation axis (O) of the first rotating member (111) and the second rotating member (112). An annular ring magnet (31) rotating together with the first rotating member (111) and a magnetic path of magnetic flux by the ring magnet (31), and the torsion bar 113) and a plurality of magnetic path forming members (41, 42) whose relative positional relationship with the plurality of magnetic poles (311, 312) of the ring magnet (31) changes according to the twist of the ring magnet (31). A pair of magnetism collecting rings (51, 52) each having an annular portion (511, 521) and magnetically coupled to each of the plurality of magnetic path forming members (41, 42), and the pair of magnetism collecting rings Based on the first magnetic detection element (61) for detecting the strength of the magnetic field between (51, 52) and the strength of the magnetic field that changes as the ring magnet (31) rotates. A second magnetic detection element (62) for detecting the rotation angle of the rotation member (111), and the first magnetic detection element (61) and the second magnetic detection element (62) are mounted on the mounting surface (63a). And a substrate (63) mounted on the substrate (63). , Said mounting surface (63a) is arranged along a direction parallel to the rotational axis (O), the torque steering angle sensor (2).

[2] In the pair of magnetism collecting rings (51, 52), the pair of side plate portions (513, 523) facing each other along the circumferential direction of the annular portion (511, 521) is replaced with the annular portion (511, 521). The torque steering angle sensor (2) according to [1], wherein the first magnetic detection element (61) is disposed between the pair of side plate portions (513, 523).

[3] The second magnetic detection element (62) faces the outer peripheral surface of the ring magnet (31), and the pair of side plate portions (513, 523) is formed from the outer peripheral surface of the ring magnet (31). Is disposed at a position away from the rotation axis (O), and the substrate (63) has a second mounting region (632) on which the second magnetic detection element (62) is mounted, the first mounting region (632). The torque steering angle sensor (2) according to [2], wherein the torque steering angle sensor (2) is provided so as to protrude from the first mounting region (631) where the magnetic detection element (61) is mounted toward the rotation axis (O).

[4] The torque steering angle sensor (2) according to any one of [1] to [3], wherein the ring magnet (31) has four or more magnetic poles.

  While the embodiments of the present invention have been described above, the embodiments described above do not limit the invention according to the claims. In addition, it should be noted that not all the combinations of features described in the embodiments are essential to the means for solving the problems of the invention.

DESCRIPTION OF SYMBOLS 11 ... Steering shaft 111 ... 1st rotation member 112 ... 2nd rotation member 113 ... Torsion bar 2 ... Torque steering angle sensor 31 ... Ring magnet 311 ... N pole 312 ... S pole 40 ... Yoke holding member 41 ... 1st magnetic yoke (Magnetic path forming member)
42. Second magnetic yoke (magnetic path forming member)
DESCRIPTION OF SYMBOLS 51 ... 1st magnetism collection ring 511,521 ... annular part 513,523 ... side plate part 52 ... 2nd magnetism collection ring 61 ... 1st magnetic detection element 62 ... 2nd magnetic detection element 63 ... board | substrate 631 ... 1st 1 mounting area 632 ... 2nd mounting area 63a ... mounting surface 63b ... non-mounting surface

Claims (4)

A connecting portion between the first rotating member and the second rotating member in an electric power steering apparatus having a first rotating member and a second rotating member connected by a torsion bar that generates a twist angle in accordance with a steering torque of the steering wheel. A torque steering angle sensor for detecting a steering angle and a steering torque of the steering wheel,
A plurality of magnetic poles having different polarities along a circumferential direction around a rotation axis of the first rotating member and the second rotating member, and an annular ring magnet that rotates together with the first rotating member;
A plurality of magnetic path forming members that form a magnetic path of magnetic flux by the ring magnet, and in which a relative positional relationship with the plurality of magnetic poles of the ring magnet changes according to torsion of the torsion bar;
A pair of magnetism collecting rings each having an annular portion formed in an annular shape and magnetically coupled to each of the plurality of magnetic path forming members;
A first magnetic sensing element for detecting the strength of the magnetic field between the pair of magnetism collecting rings;
A second magnetic detecting element for detecting a rotation angle of the first rotating member based on the strength of the magnetic field that changes with rotation of the ring magnet;
A board on which the first magnetic detection element and the second magnetic detection element are mounted on a mounting surface;
The substrate is disposed such that the mounting surface is along a direction parallel to the rotation axis.
Torque steering angle sensor. The pair of magnetism collecting rings has a pair of side plate portions opposed to each other along the circumferential direction of the annular portion on the outside of the annular portion,
The first magnetic detection element is disposed between the pair of side plate portions,
The torque steering angle sensor according to claim 1. The second magnetic detection element faces the outer peripheral surface of the ring magnet,
The pair of side plate portions are arranged at positions farther from the rotation axis than the outer peripheral surface of the ring magnet,
The substrate is provided such that a second mounting region on which the second magnetic detection element is mounted protrudes toward the rotation axis side than the first mounting region on which the first magnetic detection element is mounted. ,
The torque steering angle sensor according to claim 2. The ring magnet has 4 or more magnetic poles.
The torque steering angle sensor according to any one of claims 1 to 3.

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