JP2016090492A - Torque detection device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a torque detection device which can be easily manufactured, while securing a detection accuracy.SOLUTION: A torque detection device 1 detects a torque transmitted by a torsion bar 13 which connects an input shaft 11 and an output shaft 12, and includes: an annular magnet 20 provided on the input shaft 11; a yoke 21 provided on the output shaft 12 and arranged having predetermined intervals across the boundaries of magnetic poles of a magnet so as to be magnetically connected to an N pole of the magnet 20; a yoke 22 provided in the output shaft 12 so as not to be magnetically connected to the yoke 21 and arranged having predetermined internals across the boundaries of the magnetic poles of the magnet 10 so as not to be magnetically connected to an S pole of the magnet 20; a guide ring 23 magnetically connected to the yoke 21 with predetermined intervals; a guide ring 24 magnetically connected to the yoke 22 with predetermined intervals; and a magnetic detection element 25 for detecting a magnetic density generated between the guide rings 23 and 24.SELECTED DRAWING: Figure 1

Description

  The present invention is applied to, for example, an electric power steering device that assists steering by driving an electric motor to reduce a burden on a driver when steering a vehicle, and detects torque applied to a steering wheel. Relates to the device.

  Conventionally, an input shaft connected to a steering wheel, an output shaft connected to a steering wheel, and a connecting shaft (torsion bar) that connects the input shaft and the output shaft are provided, and a steering torque applied to the input shaft is generated by a twist angle generated in the connecting shaft. A torque detecting device for detecting is known (for example, see Patent Document 1).

  In the torque detection device described in Patent Document 1, a cylindrical permanent magnet having N poles and S poles magnetized at equal intervals in the circumferential direction is coaxially provided on the input shaft, and the magnet of the permanent magnet is provided on the output shaft. A cylindrical yoke forming a circuit is provided coaxially. The yoke includes a plurality of plate-like trapezoidal claw portions and a side wall portion formed by bending the outer peripheral portion thereof perpendicularly to the steering wheel side. In addition, a pair of magnetic flux collecting rings for inducing magnetic flux from the yoke are arranged coaxially with the yoke, and two Hall ICs (magnetic detection elements) are arranged between the pair of magnetic flux collecting rings.

  The magnetic flux emitted from the permanent magnet flows through a magnetic circuit in which a pair of magnetic yokes and a pair of magnetism collecting rings are arranged in parallel. When a one-way torque is applied to the input shaft, the torsion bar is twisted, and the relative positions of the claws of the pair of magnetic yokes and the permanent magnets change. Thereby, the magnetic resistance of the magnetic flux flowing through the pair of magnetic yokes changes. Part of the magnetic flux generated in the pair of magnetic yokes is induced by the pair of magnetism collecting rings. The induced magnetic flux is detected by two Hall ICs.

JP 2010-122104 A

  In the torque detector described in Patent Document 1, when manufacturing a pair of magnetic yokes, a plurality of flat plate-shaped trapezoidal claw portions must be formed by bending or the like, and such magnetic yokes are manufactured with high accuracy. It was not easy to do.

  Accordingly, an object of the present invention is to provide a torque detection device that can be easily manufactured while ensuring detection accuracy.

  In order to solve the above-mentioned problems, the present invention combines a first rotating shaft and a second rotating shaft, and transmits between the first rotating shaft and the second rotating shaft. A shaft-like elastic member that is twisted in accordance with torque, an annular magnet that is provided to rotate with the first rotating shaft, and one of the magnets that is provided to rotate with the second rotating shaft. A first soft magnetic member disposed with a predetermined gap between the magnetic pole boundaries of the magnet so as to be magnetically coupled to the magnetic pole of the magnet, and magnetically with respect to the first soft magnetic member The magnetic poles are spaced apart from each other so as not to be coupled with each other and rotate together with the second rotating shaft, and cross between the magnetic pole boundaries of the magnet so as to be magnetically coupled to the other magnetic pole of the magnet. Second soft magnetic member arranged with a predetermined gap and before rotating The magnetic resistance changes with respect to the third soft magnetic member that is magnetically coupled with a predetermined gap so that the magnetic resistance does not change with respect to the first soft magnetic member and the rotating second soft magnetic member. Torque detection comprising: a fourth soft magnetic member magnetically coupled with a predetermined gap so as not to cause a magnetic detection element for detecting a magnetic flux density generated between the third and fourth soft magnetic members Providing the device.

  The torque detection device according to the present invention can be easily manufactured while ensuring the detection accuracy.

It is sectional drawing of the torque detection apparatus which concerns on the 1st Embodiment of this invention. It is a disassembled perspective view which shows the structural example of the magnetic circuit in a torque detection apparatus. It is a figure for demonstrating operation | movement of a torque detection apparatus, and is a perspective view which shows the state by which the torsion bar 13 has not twisted. FIG. 5 is a perspective view illustrating a state in which the torsion bar 13 is twisted, which is a diagram for explaining the operation of the torque detection device. It is sectional drawing of 1 A of torque detection apparatuses which can detect a steering angle based on the 2nd Embodiment of this invention. FIG. 5 is a first view showing a positional relationship between the torque detection magnet 20 and the angle magnetic detection element 28 in FIG. 4, and is a top view of the torque detection device 1 </ b> A of FIG. 4 as viewed from above. FIG. 5 is a second view showing the positional relationship between the torque detection magnet 20 and the angle magnetic detection element 28 in FIG. 4, and is a top view of the torque detection device 1 </ b> A of FIG. 4 as viewed from above.

[First Embodiment]
FIG. 1 is a cross-sectional view of a torque detector according to a first embodiment of the present invention. In the following description, a direction parallel to the steering shaft is referred to as an axial direction A, and a direction orthogonal to the steering shaft is referred to as a radial direction B.

  The torque detection device 1 magnetically detects a steering torque applied to the steering shaft 10 as a rotating shaft that is rotated by a steering operation of the steering wheel. The torque detection device 1 is mounted on a vehicle, for example, and is used for detecting a steering torque applied to a steering wheel by a driver. The steering system of the vehicle is provided with an electric power steering device that assists the steering operation, and the electric motor outputs assist torque for turning the steering wheel (front wheel) according to the steering torque detected by the torque detection device 1. To do.

  The steering shaft 10 is connected to a steering wheel, and an input shaft 11 to which a steering force is input, an output shaft 12 connected to the electric power steering apparatus side, and a torsion bar 13 that connects the input shaft 11 and the output shaft 12. And is rotatably supported inside a column housing (not shown). The input shaft 11, the output shaft 12, and the torsion bar 13 are made of a magnetic material such as an iron-based metal. The torsion bar 13 has one end on the steering wheel side fixed to the input shaft 11 by a pin 14 so as not to rotate relative to the torsion bar 13, and the other end fixed to the output shaft 12 by a pin 15 so as not to rotate relative to the input shaft 11.

  The torque detection device 1 includes a cylindrical torque detection magnet 20 fixed to the input shaft 11 so as to surround the input shaft 11, and surrounds the torque detection magnet 20. The annular first and second guide rings 23 and 24 fixed to the vehicle body so as to face the end portions in the direction A, the torque detection magnet 20, and the first and second guide rings 23 and 24, respectively. Magnetic detection elements 25 arranged between the first and second guide rings 23 and 24 and the semicircular ring-shaped first and second yokes 21 and 22 arranged separately in the gap between them. A holding member 26 formed from a mold resin that holds the first and second guide rings 23 and 24, and a holding member 27 formed from a mold resin that holds the first and second yokes 21 and 22. Prepare.

  The first and second guide rings 23 and 24 and the magnetic detection element 25 are formed in the holding member 26 by insert insertion. The holding member 26 is fixed to the vehicle body via a column housing. That is, even if the steering shaft 10 rotates, the first and second guide rings 23 and 24 and the magnetic detection element 25 do not rotate with the steering shaft 10 and the positions thereof are fixed.

  On the other hand, the first and second yokes 21 and 22 are insert-molded in the holding member 27. The holding member 27 is fixedly attached around the output shaft 12 of the steering shaft 10. Accordingly, the first and second yokes 21 and 22 are arranged so as to rotate integrally with the output shaft 12 of the steering shaft 10. The holding member 27 holds the first and second yokes 21 and 22 so as to be separated along the axial direction A so that they are not magnetically coupled.

  The torque detection magnet 20 is composed of an annular magnet fixedly attached around the input shaft 11 of the steering shaft 10. The torque detection magnet 20 is disposed so as to rotate integrally with the input shaft 11 of the steering shaft 10. The torque detection magnet 20 has a pair of magnetic poles (N pole and S pole) formed along the radial direction B. In the first embodiment, the torque detection magnet 20 is on the right side (the magnetic detection element 25 and the second yoke 22 side) in FIG. 1 and on the opposite left side (the first yoke 21 side). It is a permanent magnet having a two-pole configuration in which an N pole is formed. As the torque detection magnet 20, for example, a ferrite magnet, a neodymium magnet, or the like can be used.

  In the first embodiment, the magnetic detection element 25 is configured by using a Hall element, and is configured by a pair of elements arranged so that the detection directions of the magnetic flux density are opposite to each other. The magnetic detection element 25 is arranged with a pair of elements so that the detection directions of the magnetic flux density are opposite to each other, thereby canceling the influence of the temperature characteristics of the Hall element and the detection sensitivity in the axial direction A, and the torque detection device The detection accuracy of 1 is increased.

(Configuration of magnetic circuit)
FIG. 2 is an exploded perspective view showing a configuration example of a magnetic circuit in the torque detection device 1. 2, illustration of the steering shaft 10 and the holding members 26 and 27 in FIG. 1 is omitted.

  In the first embodiment, the torque detection magnet 20 is composed of a two-pole magnet having a semi-cylindrical N pole and S pole along the radial direction B of the steering shaft 10 as described above.

  The first and second yokes 21 and 22 are provided to rotate together with the output shaft 12. The first yoke 21 has boundaries 20a and 20b between the north and south poles of the torque detecting magnet 20 so as to be magnetically coupled to one magnetic pole (N pole in the figure) of the torque detecting magnet 20. They are arranged with a predetermined gap in between. The second yoke 22 has boundaries 20a, 20b between the N pole and the S pole of the torque detection magnet 20 so as to be magnetically coupled to the other magnetic pole (S pole in the figure) of the torque detection magnet 20. They are arranged with a predetermined gap in between. The first and second yokes 21 and 22 are separated from each other so as not to be magnetically coupled, that is, along the upper and lower surfaces of the torque detecting magnet 20. The “position sufficiently spaced so as not to be magnetically coupled” means that air and / or a non-magnetic material are interposed between the two and are separated from each other.

  The first yoke 21 is provided such that the upper surface thereof is along the upper end surface of the semi-cylindrical N pole of the torque detection magnet 20, and the inner peripheral surface thereof has a predetermined gap from the outer peripheral curved surface of the torque detection magnet 20. It has a semi-circular ring shape formed so as to face each other. The lower surface of the second yoke 22 is provided along the lower end surface of the semi-cylindrical S pole of the torque detection magnet 20, and the inner peripheral surface thereof has a predetermined gap from the outer peripheral curved surface of the torque detection magnet 20. Are formed in a semicircular ring shape so as to face each other. The first and second yokes 21 and 24 may be formed so as to exist across the boundary between the north pole and the south pole of the torque detection magnet 20 by dividing the ring-shaped yoke in half. it can. In addition, a rectangular yoke may be formed by bending.

  In the axial direction A of the steering shaft 10, the first guide ring 23 has an upper surface along the upper end surface of the torque detection magnet 20 so that its inner peripheral surface faces the outer peripheral surface of the first yoke 21. Is arranged. The second guide ring 24 is arranged so that its lower surface is along the lower end surface of the torque detection magnet 20 so that its inner peripheral surface faces the outer periphery of the second yoke 22. That is, the upper surfaces of the first yoke 21 and the first guide ring 23 are arranged so as to be along the upper end surface of the torque detection magnet 20, and the lower surfaces of the second yoke 22 and the second guide ring 24 are torques. It arrange | positions so that the lower end surface of the magnet 20 for a detection may be followed.

  The first guide ring 23 is formed concentrically with the torsion bar 13 as a central axis and is disposed on the outer periphery of the first yoke 21, and a protruding portion 231 that protrudes radially outward from the annular portion 230. And an extended portion 232 extending from one end of the protruding portion 231 opposite to the annular portion 230 to the second guide ring 24 side, and an annular portion from one end of the extending portion 232 opposite to the protruding portion 231. 230, which protrudes radially outward (in the first embodiment, in a direction parallel to the protruding portion 231) and integrally has a facing portion 233 that faces a facing portion 243 of the second guide ring 24 described later. Yes.

  Similarly, the second guide ring 24 is formed concentrically with the torsion bar 13 as the central axis and is disposed on the outer periphery of the second yoke 22, and protrudes radially outward from the annular portion 240. The projecting portion 241, an extending portion 242 extending from the one end of the projecting portion 241 opposite to the annular portion 240 to the first guide ring 23 side, and one end of the extending portion 242 opposite to the projecting portion 241. And an opposing portion 243 that protrudes radially outward of the annular portion 240 (in the first embodiment, in a direction parallel to the protruding portion 241) and that opposes the opposing portion 233 of the first guide ring 23. ing.

  In the first embodiment, the first and second yokes 21 and 22 and the first and second guide rings 23 and 24 are manufactured by punching a metal plate made of the same soft magnetic member. Thus, the first and second guide rings 23 and 24 and the first and second yokes 21 and 22 can be simultaneously manufactured by a single punching process. At this time, the protruding portions 231 and 241, the extending portions 232 and 242, and the facing portions 233 and 243 of the first and second guide rings 23 and 24 extend outward from the annular portions 230 and 240 by punching. Thus, it can manufacture easily by bending the rectangular part shape | molded.

  The magnetic detection element 25 is disposed between the facing portion 233 of the first guide ring 23 and the facing portion 243 of the second guide ring 24.

  The path of the magnetic flux generated by the torque detecting magnet 20, that is, the magnetic path 1M, as indicated by a one-dot chain line in FIG. 2, the N pole of the torque detecting magnet 20 → the first yoke 21 → the first guide ring 23 → the first The second guide ring 24 → the second yoke 22 → the S pole of the torque detecting magnet 20. In the first embodiment, of the magnetic flux emitted from the N pole of the torque detection magnet 20, the magnetic flux entering the S pole of the torque detection magnet 20 without passing through the magnetic path 1M can be ignored. Small enough.

(Operation of torque detector)
3A and 3B are diagrams for explaining the operation of the torque detector 1. FIG. 3A is a perspective view showing a state where the torsion bar 13 is not twisted, and FIG. 3B is a state where the torsion bar 13 is twisted. FIG. 3, illustration of the steering shaft 10 and the holding members 26 and 27 in FIG. 1 is omitted.

  When the steering shaft 10 is rotated and steered in the clockwise direction, torque acts on the input shaft 11 and the torsion bar 13 is twisted. Then, the torque detection magnet 20 rotates clockwise and is relatively displaced from the position shown in FIG. 3A to the position shown in FIG. 3B. Then, as shown in FIG. 3B, the area where the inner peripheral surface of the first yoke 21 and the N pole side outer peripheral surface of the torque detection magnet 20 face each other, and the inner peripheral surface of the second yoke 22 and the torque detection The area where the S pole side outer peripheral surface of the magnet 20 faces is reduced. Accordingly, the area where the inner peripheral surface of the first yoke 21 and the S pole side outer peripheral surface of the torque detecting magnet 20 face each other, and the inner peripheral surface of the second yoke 22 and the N of the torque detecting magnet 20 are combined. The areas facing the pole-side outer peripheral surface increase.

  As a result, the magnetic flux density of the magnetic flux supplied from the N pole of the torque detecting magnet 20 to the first yoke 21 is rapidly lowered. Therefore, the magnetic detection element 25 detects the amount of twist of the torsion bar 13, that is, the steering force (steering torque) transmitted from the input shaft 11 to the output shaft 12 as the amount of change in magnetic flux density passing through the magnetic path 1M. Is possible.

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

(1) The magnetic detection element 25 is arranged in series with respect to the first and second guide rings 23 and 24, the first and second yokes 21 and 22, and the torque detection magnet 20 in the magnetic path 1M. Therefore, the magnitude of the magnetic flux detected by the magnetic detection element 25 is such that the inner peripheral surfaces of the first and second yokes 21 and 22 and the N pole and S pole of the torque detection magnet 20 face each other. It depends on the size of. Thereby, the magnetic detection element 25 can detect the amount of change of the magnetic flux with high accuracy in accordance with the amount of torque acting on the input shaft 11.

(2) Since the first and second yokes 21 and 22 and the first and second guide rings 23 and 24 are manufactured by punching a metal plate made of the same soft magnetic member, each member is simultaneously manufactured. And it can be manufactured easily.

(3) The upper surfaces of the first yoke 21 and the first guide ring 23 are arranged along the upper end surface of the torque detection magnet 20, and the lower surfaces of the second yoke 22 and the second guide ring 24 are torque detection. Since they are arranged along the lower end surface of the magnet 20 for use, the height of the torque detection device 1 in the axial direction A can be reduced, and the size can be reduced.

[Second Embodiment]
Next, a second embodiment of the present invention will be described with reference to FIG. FIG. 4 is a cross-sectional view of a torque detection device 1A capable of detecting a steering angle according to the second embodiment of the present invention, and corresponds to FIG. In the second embodiment, an angle magnetic detection element 28 for magnetically detecting the steering angle of the steering shaft 10 is newly provided, and the other configuration is the torque detection device of the first embodiment. 1 and common. Hereinafter, the configuration and operation of the angle magnetic detection element 28, which is the difference, will be described mainly, and the same components as those described in the first embodiment will be denoted by the same reference numerals. The description is omitted.

  This torque detection device 1A includes a torque detection unit 2 (torque detection device 1 of the first embodiment) that magnetically detects a steering torque applied to the steering shaft 10 as a rotation shaft that rotates by a steering operation of the steering wheel. The rotation detection unit 3 that magnetically detects the steering angle (rotation angle) of the steering shaft 10 is provided.

  Usually, an unillustrated electric power steering device for assisting a steering operation is provided in a vehicle steering system. The electric motor of the electric power steering device outputs a torque for turning the wheel according to the steering torque detected by the torque detection device 1A and the rotation angle (the direction of the wheel) of the steering shaft 10.

  The rotation detection unit 3 detects a rotation angle of the steering shaft 10, that is, a steering angle, and uses a cylindrical torque detection magnet 20 attached so as to rotate integrally with the steering shaft 10. The rotation detection unit 3 includes the above-described torque detection magnet 20 and an angle magnetic detection element 28 disposed on the side of the torque detection magnet 20 and above the holding member 27. Here, “side” means outward in the radial direction B.

  The angle magnetic detection element 28 detects a change in magnetic flux density caused by approaching or moving away from the magnetic pole (N pole or S pole) of the torque detection magnet 20 that rotates as the input shaft 11 rotates. The angle magnetic detection element 28 may be insert-molded in the holding member 27. Since the holding member 27 is fixed to the vehicle body via the column housing, even if the steering shaft 10 rotates, the angle magnetic detection element 28 does not rotate with the steering shaft 10 and its position is fixed.

  In the angle magnetic detection element 28, the change direction of the magnetic flux density is detected in a biaxial direction that is a radial direction B orthogonal to the steering shaft 10 and a direction orthogonal to the radial direction B. Here, “the radial direction B” and “the direction orthogonal to the radial direction B” include errors within ± 10 ° in the respective directions. As the angle magnetic detection element 28, for example, a Hall element is used, but other elements such as an MR element, a GIG element, and a GMR element may be used.

  5 is a diagram showing a positional relationship between the torque detection magnet 20 and the angle magnetic detection element 28 in FIG. 4, and is a top view of the torque detection device 1A of FIG. 4 as viewed from above. FIG. 5A shows a state in which the angle magnetic detection element 28 is closest to the approximate center between the boundaries 20a and 20b between the N pole and the S pole of the torque detection magnet 20. FIG. 5B shows a state in which the angle magnetic detection element 28 is closest to the boundary 20 a between the N pole and the S pole of the torque detection magnet 20.

  When the steering shaft 10 rotates and the angle magnetism detecting element 28 is closest to the N pole of the torque detecting magnet 20 as shown in FIG. 5A, the magnetic flux radiated from the N pole of the torque detecting magnet 20 The magnetic flux passing through the angle magnetic detection element 28 side is the largest. On the other hand, when the steering shaft 10 rotates clockwise and the angle magnetic detection element 28 comes closest to the boundary 20a between the N pole and the S pole of the torque detection magnet 20, as shown in FIG. Among the magnetic fluxes radiated from the north pole of the magnet 20 for use, the magnetic flux passing through the angle magnetic detection element 28 side is the smallest.

  As the steering shaft 10 rotates in this manner, the angle magnetic detection element 28 approaches or separates from the magnetic pole (N pole or S pole) of the torque detection magnet 20, so that the angle magnetic detection element 28 becomes a magnetic flux. Changes in density can be detected. Then, the angle magnetic detection element 28 outputs a detection signal corresponding to the magnetic flux density to a signal processing circuit (not shown). The signal processing circuit detects the rotation angle of the steering shaft 10, that is, the steering angle of the steering shaft 10, based on the detection signal from the angle magnetic detection element 28.

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

(1) Utilizing a cylindrical torque detection magnet 20 attached so as to rotate integrally with the steering shaft 10, angle magnetic detection is provided on the side of the torque detection magnet 20 and above the holding member 27. The steering angle of the steering shaft 10 can be detected simply by disposing the element 28.

(Summary of embodiment)
Next, the technical idea grasped from the first and second embodiments described above will be described with reference to the reference numerals in the embodiments. However, the reference numerals and the like in the following description are not intended to limit the constituent elements in the claims to the members and the like specifically shown in the embodiments.

[1] The first rotating shaft (11) and the second rotating shaft (12) are coupled and transmitted between the first rotating shaft (11) and the second rotating shaft (12). A shaft-like elastic member (torsion bar 13) which is twisted according to the torque to be rotated, an annular magnet (20) provided to rotate together with the first rotating shaft (11), and the second rotating shaft (12) provided to rotate together with the magnetic pole (N pole) of the magnet (20) so as to be magnetically coupled to the boundary of the magnetic pole (S pole and N pole) of the magnet (20). The first soft magnetic member (21) arranged with a predetermined gap between (20a, 20b) and a position separated so as not to be magnetically coupled to the first soft magnetic member (21) And provided to rotate together with the second rotating shaft (12), and the magnet (20) The second soft magnetic member (22) disposed with a predetermined gap between the magnetic pole boundaries (20a, 20b) of the magnet (20) so as to be magnetically coupled to the other magnetic pole (S pole). ), The third soft magnetic member (23) magnetically coupled with a predetermined gap so that the magnetic resistance does not change with respect to the rotating first soft magnetic member (21), and the rotating first soft magnetic member (21). A fourth soft magnetic member (24) magnetically coupled with a predetermined gap so that the magnetic resistance does not change with respect to the second soft magnetic member (22), and the third and fourth soft magnetic members ( 23, 24) a torque detecting device (1) comprising a magnetic detecting element (25) for detecting a magnetic flux density generated between them.
[2] The first soft magnetic member (21) is provided so that the upper surface thereof is along the upper end surface of the magnet (20), and the inner peripheral surface thereof is a predetermined gap from the outer peripheral curved surface of the magnet (20). The second soft magnetic member (22) has a semicircular ring shape formed so as to face each other, and the lower surface thereof is provided along the lower end surface of the magnet (20), and the inner circumference thereof The third soft magnetic member (23) has a semicircular ring shape formed such that the surface faces the outer peripheral curved surface of the magnet (20) with a predetermined gap, and the upper surface of the third soft magnetic member (23) is the magnet (20 And a ring shape formed so that the inner peripheral surface thereof faces the outer peripheral curved surface of the first soft magnetic member (21) with a predetermined gap. 4, the lower surface of the soft magnetic member (24) is along the lower end surface of the magnet (20). The torque according to [1], wherein the torque is provided and has an inner peripheral surface formed in a ring shape so as to face the outer peripheral curved surface of the first soft magnetic member (21) with a predetermined gap. Detection device (1).

[3] Rotation detection that detects the rotation angle of the first rotating shaft (11) by detecting the magnetic flux density that is arranged on the side of the magnet (20) and changes as the magnet (20) rotates. The torque detection device (1A) according to [1] or [2], including a section (28).

  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.

  The present invention can be appropriately modified and implemented without departing from the spirit of the present invention. For example, in the above embodiment, the torque detection magnet 20 has a two-pole configuration consisting of a pair of magnetic poles (N pole and S pole) along the radial direction B. Also good. In this case, the first and second yokes may be provided for each magnetic pole corresponding to the number of poles of the torque detection magnet and the boundary between the N pole and the S pole.

  In the above embodiment, the magnetic detection element 25 detects the magnetic flux, but the number and shape of the magnetic detection elements 25 are not particularly limited.

  In the above embodiment, the inner peripheral surfaces of the first and second yokes 21 and 22 are arranged so as to face each other with a predetermined gap from the outer peripheral curved surface of the torque detecting magnet 20. It is only necessary that the magnetic poles of the first yoke 21 are arranged with a predetermined gap so as to be magnetically coupled to the magnetic poles of the 20 magnetic poles. You may arrange | position with the predetermined clearance gap with respect to the lower surface of the magnet 20 for torque detection.

  In the above embodiment, the inner peripheral surfaces of the first and second guide rings 23 and 24 are arranged so as to oppose the outer peripheral surfaces of the first and second yokes 21 and 22. Therefore, the lower surface of the first guide ring 23 is on the upper surface of the first yoke 21, and the upper surface of the second guide ring 24 is on the second yoke 22. You may arrange | position with a predetermined clearance with respect to the lower surface.

  In the above-described embodiment, the angle magnetic detection element 28 is disposed on the side of the torque detection magnet 20 and above the holding member 27. However, the first magnetic force detection unit 1A of the torque detection device 1A is configured as the first. As long as it is difficult to be affected by magnetic interference from the first and second yokes 21 and 22 and the first and second guide rings 23 and 24, other locations may be used.

  In the above embodiment, the case where the steering angle, that is, the rotation angle is detected has been described. However, by providing a means for detecting the rotation speed of the steering shaft 10, the absolute rotation position of the steering shaft 10 is detected. It may be.

DESCRIPTION OF SYMBOLS 1,1A ... Torque detection apparatus 10 ... Steering shaft 11 ... Input shaft 12 ... Output shaft 13 ... Torsion bar (elastic member)
1M ... Magnetic path 20 ... Torque detection magnets 20a, 20b ... Magnetic pole boundary 21 ... First yoke 22 ... Second yoke 23 ... First guide ring 24 ... Second guide ring 25 ... Magnetic detection element 28 ... Magnetic detector for angle

Claims (3)

A shaft-like elastic member that couples the first rotating shaft and the second rotating shaft and is twisted according to the torque transmitted between the first rotating shaft and the second rotating shaft;
An annular magnet provided to rotate with the first rotating shaft;
A first rotating shaft provided to rotate together with the second rotating shaft, and arranged with a predetermined gap between the magnetic pole boundaries of the magnet so as to be magnetically coupled to one magnetic pole of the magnet; A soft magnetic member;
The first soft magnetic member is provided so as not to be magnetically coupled to the first soft magnetic member so as to rotate together with the second rotating shaft, and is magnetically coupled to the other magnetic pole of the magnet. A second soft magnetic member disposed with a predetermined gap across the magnetic pole boundary of the magnet,
A third soft magnetic member magnetically coupled with a predetermined gap so that the magnetic resistance does not change with respect to the rotating first soft magnetic member;
A fourth soft magnetic member magnetically coupled with a predetermined gap so that the magnetic resistance does not change with respect to the rotating second soft magnetic member;
A magnetic detection element for detecting a magnetic flux density generated between the third and fourth soft magnetic members;
A torque detection device comprising: The first soft magnetic member has a semicircle formed so that an upper surface thereof is provided along an upper end surface of the magnet, and an inner peripheral surface thereof is opposed to the outer peripheral curved surface of the magnet with a predetermined gap. Ring shape,
The second soft magnetic member is a semicircle formed such that its lower surface is provided along the lower end surface of the magnet, and its inner peripheral surface is opposed to the outer peripheral curved surface of the magnet with a predetermined gap. Ring shape,
The third soft magnetic member is provided so that the upper surface thereof is along the upper end surface of the magnet, and the inner peripheral surface thereof is opposed to the outer peripheral curved surface of the first soft magnetic member with a predetermined gap. The formed ring shape
The lower surface of the fourth soft magnetic member is provided along the lower end surface of the magnet, and the inner peripheral surface thereof is opposed to the outer peripheral curved surface of the first soft magnetic member with a predetermined gap. Has a formed ring shape,
The torque detection device according to claim 1. The rotation detection part which is arrange | positioned at the side of the said magnet and detects the rotation angle of a 1st rotating shaft by detecting the magnetic flux density which changes with rotation of the said magnet was provided. Torque detection device.

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