Torque detection system

Abstract

A first magnetic detection portion (61) in a torque sensor of a torque detection system overlaps a magnetic pole of a magnet (30) projected in a radial direction when the magnetic pole, for example, an N pole, of the magnet (30) is projected in the radial direction in a state in which a torque is not generated. Also, a second magnetic detection portion (62) overlaps a magnetic pole of the magnet (30) projected in the radial direction when a magnetic pole different from the magnetic pole of the magnet (30) overlapping the first magnetic detection portion (61), for example, an S pole, is projected in the radial direction in the state in which the torque is not generated. Also, a motor control device corresponding to an arithmetic portion of the torque detection system calculates a sum of a value related to a strength of a magnetic field detected by the first magnetic detection portion (61) and a value related to a strength of a magnetic field detected by the second magnetic detection portion (62). In addition, the motor control device calculates a steering torque on the basis of the calculated sum.

Description

[0001] Cross-reference to related applications

[0002] This application is based on Japanese Patent Application No. 2021-173061 filed on October 22, 2021 and Japanese Patent Application No. 2022-140804 filed on September 5, 2022, the contents of which are incorporated herein by reference. Technical Field

[0003] This disclosure relates to a torque detection system. Background Technology

[0004] Conventionally, as described in Patent Document 1, a torque sensor is known that includes a magnet, a yoke, a magnetic collecting unit, and a Hall effect IC. The magnet rotates together with the steering shaft. Furthermore, the yoke, by rotating together with the steering shaft, changes the magnetic field generated by the magnet. The magnetic collecting unit guides the changing magnetic field through the yoke to the Hall effect IC. Moreover, the torque applied to the steering shaft is detected by detecting the strength of this magnetic field using the Hall effect IC.

[0005] Existing technical documents

[0006] Patent documents

[0007] Patent Document 1: Japanese Patent No. 5675700 Summary of the Invention

[0008] According to the inventor's research, if a motor or the like is placed near the torque sensor described in Patent Document 1, the magnetic collector guides the magnetic field that changes through the yoke to the Hall IC, and also guides the magnetic field generated by the motor or the like to the Hall IC. Therefore, the noise detected by the Hall IC increases, thus reducing the accuracy of torque detection. Therefore, to improve the torque sensor's resistance to interference magnetic fields, it is considered to remove the magnetic collector. However, the magnetic collector protects the Hall IC from the magnetic field leaking from the magnet. Therefore, if the magnetic collector is removed and the relative position of the Hall IC relative to the yoke shifts, the Hall IC will detect not only the intensity of the magnetic field that changes through the yoke, but also the intensity of the magnetic field leaking from the magnet. Therefore, in the torque sensor described in Patent Document 1, if the magnetic collector is removed and the relative position of the Hall IC relative to the yoke shifts, the magnetic field leaking from the magnet becomes noise, thus reducing the sensor's tolerance to the noise magnetic field leaking from the magnet.

[0009] The purpose of this disclosure is to provide a torque detection system that improves tolerance to noisy magnetic fields leaking from the magnet, even if the magnet collecting part and the relative position of the magnetic detection part with respect to the yoke are offset after removing the magnet collecting part.

[0010] According to one aspect of this disclosure, a torque detection system is provided for detecting torque generated in a detection object. The system comprises: a torque sensor having a magnet, a rotating body, a yoke, a first magnetic detection unit, and a second magnetic detection unit. The magnet generates a magnetic field and rotates with the detection object about an axially extending axis. The rotating body is annular and rotates with the detection object. The yoke includes an annular portion and a claw portion. The annular portion is annular and rotates with the rotating body. The claw portion protrudes from the annular portion toward the axial direction and faces the magnet in a direction orthogonal to the axial direction, and concentrates the magnetic field generated by the magnet by rotating with the annular portion. The first magnetic detection unit overlaps with the annular portion projected when the annular portion is projected axially, and detects torque that changes by varying the relative angle of the yoke with respect to the magnet in the direction of the magnet's rotation. The magnetic field strength is measured by the second magnetic detection unit overlapping the annular portion projected when the annular portion is projected along the axial direction, and detecting the magnetic field strength corresponding to the torque and varying by changing the relative angle between the yoke and the magnet in the rotational direction of the magnet; and by the calculation unit calculating the torque based on signals from the first and second magnetic detection units; the first magnetic detection unit overlaps with the magnetic poles of the magnet projected when the magnetic poles of the magnet are projected along a direction orthogonal to the axial direction when no torque is generated, and the second magnetic detection unit overlaps with the magnetic poles of the magnet projected when the magnetic poles of the magnet overlapping with the first magnetic detection unit are projected along a direction orthogonal to the axial direction when no torque is generated, and the calculation unit calculates the sum of the value related to the magnetic field strength detected by the first magnetic detection unit and the value related to the magnetic field strength detected by the second magnetic detection unit, and calculates the torque based on the calculated sum.

[0011] Furthermore, according to one aspect of this disclosure, a torque detection system is provided for detecting torque generated in a detection object, comprising: a torque sensor having a magnet, a rotating body, a yoke, a first magnetic detection unit, and a second magnetic detection unit; the magnet generates a magnetic field and rotates together with the detection object about an axially extending axis; the rotating body is annular and rotates together with the detection object; the yoke includes an annular portion and a claw portion; the annular portion is annular and rotates together with the rotating body; the claw portion is annular and faces the magnet in a direction orthogonal to the axial direction by protruding from the annular portion, and concentrates the magnetic field generated by the magnet by rotating together with the annular portion; the first magnetic detection unit overlaps with the annular portion projected when the annular portion is projected along the axial direction, and detects the strength of the magnetic field corresponding to the torque and varying by changing the relative angle between the yoke and the magnet in the rotation direction of the magnet; the second magnetic detection unit overlaps with the annular portion projected when the annular portion is projected along the axial direction. The system includes a magnetic field detection unit and a calculation unit that calculates the torque based on signals from a first magnetic detection unit and a second magnetic detection unit. The first magnetic detection unit overlaps with the magnetic poles of a magnet projected in a direction orthogonal to the axial direction when no torque is generated, and is positioned on the side axially closer than the centerline extending in a direction orthogonal to the axial direction through the center of the magnetic poles. The second magnetic detection unit overlaps with the magnetic poles of a magnet projected in a direction orthogonal to the axial direction when no torque is generated, and is positioned on the side axially closer than the centerline. The calculation unit calculates the sum of a value related to the strength of the magnetic field detected by the first magnetic detection unit and a value related to the strength of the magnetic field detected by the second magnetic detection unit, and calculates the torque based on the calculated sum.

[0012] Furthermore, according to one aspect of this disclosure, a torque detection system is provided that detects torque generated by a detection object, comprising: a torque sensor having a magnet, a rotating body, a yoke, a first magnetic detection unit, and a second magnetic detection unit; the magnet generates a magnetic field and rotates together with the detection object about an axis extending axially; the rotating body is annular and rotates together with the detection object; the yoke includes an annular portion, a claw portion, and a flange portion; the annular portion is annular and rotates together with the rotating body; the claw portion protrudes from the annular portion toward the axial direction and faces the magnet in a direction orthogonal to the axial direction, and concentrates the magnetic field generated by the magnet by rotating together with the annular portion; the flange portion protrudes from the annular portion toward the axial direction; the first magnetic detection unit overlaps with the flange portion projected when projected in a direction orthogonal to the axial direction; and detects torque corresponding to the torque generated by the yoke relative to the magnet in the magnet's rotation direction. The magnetic field strength varies with the relative angle of the magnet and the magnetic field intensity. The second magnetic detection unit overlaps with the flange portion projected when the flange portion is projected in a direction orthogonal to the axial direction, and detects the magnetic field strength corresponding to the torque and varying with the relative angle of the yoke relative to the magnet in the rotation direction of the magnet. The calculation unit calculates the torque based on signals from the first and second magnetic detection units. The first magnetic detection unit overlaps with the magnetic pole of the magnet projected when the magnetic pole of the magnet is projected in a direction orthogonal to the axial direction when no torque is generated. The second magnetic detection unit overlaps with the magnetic pole of the magnet projected when the magnetic pole of the magnet overlapping with the first magnetic detection unit is projected in a direction orthogonal to the axial direction when no torque is generated. The calculation unit calculates the sum of the value related to the magnetic field strength detected by the first magnetic detection unit and the value related to the magnetic field strength detected by the second magnetic detection unit, and calculates the torque based on the calculated sum.

[0013] Therefore, the direction of the magnetic field detected by the second magnetic detection unit in the magnetic field leaking from the magnet is opposite to the direction of the magnetic field detected by the first magnetic detection unit in the magnetic field leaking from the magnet. Thus, the noise detected by the first and second magnetic detection units cancels each other out. Furthermore, the arithmetic unit calculates the sum of the values ​​related to the strength of the magnetic field detected by the first and second magnetic detection units. This removes the noise detected by the first and second magnetic detection units. Therefore, even if the relative positions of the magnetic collecting unit and the magnetic detection unit relative to the yoke shift, the tolerance to the noise magnetic field leaking from the magnet is improved.

[0014] Furthermore, the parenthesized reference symbols used to annotate each constituent element, etc., represent an example of the correspondence between that constituent element, etc., and the specific constituent elements, etc., described in the embodiments described later. Attached Figure Description

[0015] Figure 1This is a structural diagram of a steering system using a torque sensor of the torque detection system according to the first embodiment.

[0016] Figure 2 This is an exploded 3D view of a part of the steering system.

[0017] Figure 3 This is a 3D view of the torque sensor.

[0018] Figure 4 yes Figure 3 Sectional view along line IV-IV.

[0019] Figure 5 This is a three-dimensional cross-sectional view of the torque sensor.

[0020] Figure 6 yes Figure 3 Sectional view along line VI-VI.

[0021] Figure 7 This is a three-dimensional cross-sectional view of the torque sensor.

[0022] Figure 8 It is a three-dimensional diagram showing the positional relationship of the magnet, the first yoke, the second yoke, the first magnetic detection unit, and the second magnetic detection unit of the torque sensor.

[0023] Figure 9 From Figure 8 The IX view is observed from the perspective of the view.

[0024] Figure 10 From Figure 8 The X-view observed.

[0025] Figure 11 From Figure 8 The view observed from XI.

[0026] Figure 12 This is a side view showing the neutral state of the magnet, first yoke, and second yoke of the torque sensor.

[0027] Figure 13 It is a side view of the magnet, first yoke, and second yoke of the torque sensor when the steering wheel of the steering system rotates.

[0028] Figure 14 This is a schematic diagram illustrating the situation where the magnetic field leaking from the magnet passes through the first magnetic detection unit and the second magnetic detection unit.

[0029] Figure 15 It is a graph showing the relationship between the rotation angle of the magnet and the SN ratio of the first magnetic detection unit and the second magnetic detection unit.

[0030] Figure 16 This is a side view of the magnet, first yoke, and second yoke of the torque sensor when the steering wheel is rotated.

[0031] Figure 17 This is a perspective view showing the positional relationship between the magnet, the first yoke, the second yoke, the first magnetic detection unit, and the second magnetic detection unit in the torque sensor of the torque detection system of the second embodiment.

[0032] Figure 18 From Figure 17 The XVIII view is observed from the perspective.

[0033] Figure 19 From Figure 17 The XIX view is observed from the perspective of the view.

[0034] Figure 20 From Figure 17 The view observed by XX.

[0035] Figure 21 This is a perspective view showing the positional relationship between the magnet, the first yoke, the second yoke, the first magnetic detection unit, and the second magnetic detection unit in the torque sensor of the torque detection system according to the third embodiment.

[0036] Figure 22 From Figure 21 The view observed by XXII.

[0037] Figure 23 From Figure 21 The view observed by XXIII.

[0038] Figure 24 From Figure 21 The view observed in XXIV.

[0039] Figure 25 yes Figure 21 XXV-XXV line sectional view.

[0040] Figure 26 This is a side view showing the magnet, the first yoke, and the second yoke in the torque sensor of the torque detection system according to the fourth embodiment.

[0041] Figure 27 yes Figure 26 Enlarged image of Part XXVII.

[0042] Figure 28 yes Figure 27 Sectional view along line XXIII-XXIII.

[0043] Figure 29 This is an enlarged view of the second yoke.

[0044] Figure 30 yes Figure 29 Sectional view along line XXX-XXX.

[0045] Figure 31 This is an enlarged view of the first protrusion in the first yoke of the comparative example.

[0046] Figure 32 This is an enlarged view of the second protrusion in the second yoke of the comparative example.

[0047] Figure 33 It is a graph showing the relationship between the first length, the second length, and the intensity of the noise magnetic field.

[0048] Figure 34 This is an enlarged view of the first yoke in the torque sensor of the torque detection system according to the fifth embodiment.

[0049] Figure 35 yes Figure 34 XXXV-XXXV line section view.

[0050] Figure 36 This is an enlarged view of the second yoke.

[0051] Figure 37 yes Figure 36 Sectional view along line XXXVII-XXXVII.

[0052] Figure 38 This is an enlarged view of the first yoke in the torque sensor of the torque detection system according to the sixth embodiment.

[0053] Figure 39 yes Figure 34 A sectional view along the XXXIX-XXXIX line.

[0054] Figure 40 This is an enlarged view of the second yoke.

[0055] Figure 41 yes Figure 40 XLI-XLI line sectional view.

[0056] Figure 42 This is a cross-sectional view of the magnet, first yoke, second yoke, substrate, and first magnetic detection unit in the torque sensor of the torque detection system according to the seventh embodiment.

[0057] Figure 43 This is a cross-sectional view of the magnet, first yoke, second yoke, substrate, and first magnetic detection unit in the torque sensor of the torque detection system according to the eighth embodiment.

[0058] Figure 44 This is a cross-sectional view of the magnet, first yoke, second yoke, substrate, and first magnetic detection unit in the torque sensor of the torque detection system according to the ninth embodiment.

[0059] Figure 45This is a cross-sectional view of the magnet, first yoke, second yoke, substrate, and first magnetic detection unit in the torque sensor of the torque detection system according to the tenth embodiment.

[0060] Figure 46 This is a diagram showing the positional relationship between the magnet, the first yoke, the second yoke, the substrate, and the first magnetic detection unit in the torque sensor of the torque detection system according to the eleventh embodiment.

[0061] Figure 47 This is a diagram showing the positional relationship between the magnet, the first yoke, the second yoke, the substrate, the first magnetic detection unit, and the second magnetic detection unit in the torque sensor of the torque detection system according to the twelfth embodiment.

[0062] Figure 48 This is a diagram showing the positional relationship between the magnet, the first yoke, the second yoke, the substrate, and the first magnetic detection unit in the torque sensor of the torque detection system according to the thirteenth embodiment. Detailed Implementation

[0063] Hereinafter, embodiments will be described with reference to the accompanying drawings. Furthermore, in the various embodiments described below, the same or equivalent parts will be labeled with the same reference numerals, and their descriptions will be omitted.

[0064] (First Implementation)

[0065] The torque sensor 25 of the torque detection system in this embodiment is used, for example, in the steering system 1 of a vehicle. First, the steering system 1 will be described.

[0066] Steering system 1 assists in steering to change the direction of wheels 17. Specifically, as follows: Figure 1 and Figure 2 As shown, the steering system 1 includes a steering wheel 5, a first steering shaft 11, a torsion bar 13, and a second steering shaft 12. Additionally, the steering system 1 includes a pivot pin 14, a pinion 15, a rack and pinion shaft 16, a wheel 17, a torque sensor 25, a motor control device 18, a motor 19, and a reduction gear 20.

[0067] like Figure 1 As shown, the steering wheel 5 is rotated by the vehicle's driver or autonomous driving system.

[0068] The first steering shaft 11 is connected to the steering wheel 5. Therefore, the first steering shaft 11 rotates together with the steering wheel 5.

[0069] Torsion bar 13 is connected to the first steering shaft 11. Therefore, torsion bar 13 rotates together with steering wheel 5 and the first steering shaft 11.

[0070] The second steering shaft 12 is connected to the torsion bar 13. Therefore, the torsion bar 13 rotates together with the steering wheel 5, the first steering shaft 11, and the torsion bar 13.

[0071] like Figure 2 As shown, the pin 14 is inserted into a hole formed in the first steering shaft 11 and into a hole in the torsion bar 13 corresponding to the hole in the first steering shaft 11. This secures the first steering shaft 11 and the torsion bar 13. Similarly, the pin 14 is inserted into a hole formed in the second steering shaft 12 and into a hole in the torsion bar 13 corresponding to the hole in the second steering shaft 12. This secures the second steering shaft 12 and the torsion bar 13.

[0072] like Figure 1 As shown, pinion 15 is connected to the second steering shaft 12. Furthermore, pinion 15 meshes with rack shaft 16, which will be described later. Moreover, pinion 15 converts the rotational motion of the second steering shaft 12 into the linear motion of rack shaft 16.

[0073] The rack shaft 16 is connected to the wheel 17 via a tie rod (not shown). Furthermore, the rack shaft 16 changes the direction of the wheel 17 by performing linear motion.

[0074] A portion of a torsion bar 13 is inserted into the torque sensor 25. Furthermore, the torque sensor 25 detects a signal corresponding to the torque generated in the torsion bar 13 by the rotation of the steering wheel 5. Thus, the torque sensor 25 detects the steering torque. Moreover, the torque sensor 25 outputs a signal corresponding to the detected steering torque to the motor control device 18, which will be described later. Details of the torque sensor 25 will be described later. Furthermore, the steering torque is the torque applied when the steering wheel 5 is rotated.

[0075] The motor control device 18 is primarily composed of a microcomputer or similar component, and includes a CPU, ROM, flash memory, RAM, I / O, drive circuitry, and a bus connecting these components. Furthermore, the motor control device 18 executes a program stored in the ROM. As a result, the motor control device 18 calculates the rotation angle of the motor 19 (described later). Moreover, the motor control device 18 calculates the steering torque based on a signal corresponding to the steering torque received from the torque sensor 25. Finally, based on the calculated rotation angle and steering torque of the motor 19, the motor control device 18 controls the rotation of the motor 19 (described later).

[0076] Motor 19 rotates based on the output from motor control device 18. As a result, motor 19 generates torque.

[0077] The reduction gear 20 is connected to the motor 19 and the second steering shaft 12. Furthermore, the reduction gear 20 reduces the rotational speed of the motor 19 and transmits the torque generated by the motor 19 to the second steering shaft 12. This assists in steering for changing the direction of the wheels 17.

[0078] The above constitutes steering system 1. Next, the structure of torque sensor 25 will be described.

[0079] like Figures 2 to 11 As shown, the torque sensor 25 includes a magnet 30, a rotating body 35, a first yoke 361, a second yoke 362, and a fixing sleeve 354. In addition, the torque sensor 25 includes a substrate 60, a first magnetic detection unit 61, a second magnetic detection unit 62, a sensor housing 75, a terminal 80, a first cover 85, and a second cover 86.

[0080] like Figure 2 , Figures 8-11 As shown, the magnet 30 is formed in a ring shape. Furthermore, the magnet 30 is connected to the end of the first steering shaft 11. A portion of a torsion bar 13 is inserted into the hole of the magnet 30. The axis of the magnet 30 and the axis of the torsion bar 13 are located on the same axis. Therefore, the magnet 30 rotates together with the first steering shaft 11 about the axis of the torsion bar 13. Moreover, the magnet 30 is magnetized in such a way that its magnetic poles alternately reverse in the direction of rotation. The magnet 30 has 16 magnetic poles.

[0081] For convenience, the radial direction of magnet 30 will be described as radial only. Similarly, the axial direction (Da) of magnet 30 will be described as axial only. Furthermore, the circumferential direction centered on the axis of magnet 30 will be described as circumferential only.

[0082] like Figures 3-7 As shown, the rotating body 35 is formed in a cylindrical shape. Furthermore, the axis of the rotating body 35 and the axis of the magnet 30 are located on the same axis. Therefore, the axes of the rotating body 35, the magnet 30, and the torsion bar 13 are all on the same axis.

[0083] like Figure 2 and Figure 3 As shown, the first yoke 361 is formed into a cylindrical shape from a soft magnetic material. In addition, the first yoke 361 includes a first yoke annular portion 370 and a plurality of first yoke claw portions 372.

[0084] The first yoke annular portion 370 corresponds to the first annular portion and is formed in a circular shape. In addition, a portion of the first yoke annular portion 370 is inserted into a hole in the radially extending rotating body 35.

[0085] The first yoke claw portion 372 corresponds to the first claw portion and protrudes axially Da from the inner side of the first yoke annular portion 370. Furthermore, the first yoke claw portion 372 is formed into a pointed shape whose width decreases from the inner side of the first yoke annular portion 370 towards the front end. Moreover, the first yoke claw portion 372 is connected to the inner surface of the rotating body 35. Additionally, the first yoke claw portion 372 is radially opposed to the outer surface of the magnet 30. Furthermore, because the holes in the rotating body 35 are formed at predetermined intervals along the circumferential direction, the first yoke claw portions 372 are also formed at predetermined intervals along the circumferential direction.

[0086] Like the first yoke 361, the second yoke 362 is formed into a ring shape from a soft magnetic material. Furthermore, the second yoke 362 is integrally formed with, for example, the rotating body 35 and the first yoke 361. Moreover, the second yoke 362 includes a second yoke ring portion 380 and a plurality of second yoke claw portions 382.

[0087] The second yoke annular portion 380 corresponds to the second annular portion and is formed in a circular shape. In addition, a portion of the second yoke annular portion 380 is inserted into a hole in the radially extending rotating body 35.

[0088] The second yoke claw portion 382 corresponds to the second claw portion and protrudes axially Da from the inner side of the second yoke annular portion 380. Furthermore, the second yoke claw portion 382 is formed into a pointed shape whose width decreases from the inner side of the second yoke annular portion 380 towards the front end. Moreover, the second yoke claw portion 382 is connected to the inner surface of the rotating body 35. Additionally, the second yoke claw portion 382 is radially opposed to the outer surface of the magnet 30. Furthermore, because the holes in the rotating body 35 are formed at predetermined intervals along the circumferential direction, the second yoke claw portions 382 are also formed at predetermined intervals along the circumferential direction. Furthermore, the second yoke claw portions 382 are disposed between adjacent first yoke claw portions 372. Therefore, the first yoke claw portions 372 and the second yoke claw portions 382 are alternately arranged in the circumferential direction. Moreover, the number of second yoke claw portions 382 is the same as the number of first yoke claw portions 372. Furthermore, the sum of the number of first yoke claw portions 372 and second yoke claw portions 382 is the same as the number of magnetic poles of the magnet 30. Furthermore, in Figures 3-7 In order to avoid the complexity of the illustration, a portion of the first yoke claw 372 and the second yoke claw 382 has been omitted.

[0089] The fixing sleeve 354 is formed in a cylindrical shape. Furthermore, the fixing sleeve 354 is connected to the inner surface of the rotating body 35. Moreover, the fixing sleeve 354 is connected to the second steering shaft 12. Therefore, the rotating body 35 rotates together with the second steering shaft 12.

[0090] Substrate 60 is a printed circuit board. A first magnetic detection unit 61 is mounted on substrate 60. The first magnetic detection unit 61 may include, for example, a Hall element or an MR element (not shown). The first magnetic detection unit 61 detects the strength of an axial magnetic field (Da) applied to it using these elements. Furthermore, the first magnetic detection unit 61 outputs a signal corresponding to the detected magnetic field strength to the motor control device 18. A second magnetic detection unit 62 is mounted on substrate 60. The second magnetic detection unit 62 may include, for example, a Hall element or an MR element (not shown). Like the first magnetic detection unit 61, the second magnetic detection unit 62 detects the strength of an axial magnetic field (Da) applied to it using these elements. Furthermore, the second magnetic detection unit 62 outputs a signal corresponding to the detected magnetic field strength to the motor control device 18. MR is an abbreviation for Magneto Resistive.

[0091] In addition, such as Figures 8-11 As shown, the first magnetic detection unit 61 overlaps with the first yoke annular portion 370 projected when the first yoke annular portion 370 is projected along the axial direction Da. Furthermore, the first magnetic detection unit 61 overlaps with the second yoke annular portion 380 projected when the second yoke annular portion 380 is projected along the axial direction Da. Additionally, in the initial state, the first magnetic detection unit 61 overlaps with the N pole projected when the N pole of the magnet 30 is projected radially. Moreover, in the initial state, the first magnetic detection unit 61 does not overlap with the S pole projected when the S pole of the magnet 30 is projected radially. Furthermore, the initial state is as described later, when the steering wheel 5 is not rotated, i.e., when no steering torque is generated.

[0092] Furthermore, the second magnetic detection unit 62 overlaps with the first yoke annular portion 370 projected when the first yoke annular portion 370 is projected along the axial direction Da. Also, the second magnetic detection unit 62 overlaps with the second yoke annular portion 380 projected when the second yoke annular portion 380 is projected along the axial direction Da. Additionally, in the initial state, the second magnetic detection unit 62 overlaps with the S pole projected when the S pole of the magnet 30 is projected radially. Furthermore, in the initial state, the second magnetic detection unit 62 does not overlap with the N pole projected when the N pole of the magnet 30 is projected radially. Alternatively, in the initial state, the first magnetic detection unit 61 may be radially opposed to the S pole of the magnet 30, but not radially opposed to the N pole of the magnet 30. In this case, the second magnetic detection unit 62 is radially opposed to the N pole of the magnet 30, but not radially opposed to the S pole of the magnet 30.

[0093] In addition, such as Figure 9 As shown, the first magnetic detection unit 61 and the second magnetic detection unit 62 are arranged on the same circle C centered on the axis of the rotating body 35. Here, as... Figure 10 and Figure 11 As shown, the axial distance Da from the second yoke annular portion 380 to the first magnetic detection portion 61 is defined as the first yoke distance Ly1. Furthermore, the axial distance Da from the second yoke annular portion 380 to the second magnetic detection portion 62 is defined as the second yoke distance Ly2. Moreover, the first yoke distance Ly1 and the second yoke distance Ly2 are the same. In this context, "the same" includes a manufacturing tolerance range.

[0094] Additionally, here, as Figure 9As shown, the line connecting the axis of magnet 30 and the first magnetic detection unit 61 is designated as the first straight line L1. The line connecting the axis of magnet 30 and the second magnetic detection unit 62 is designated as the second straight line L2. Furthermore, the angle between the detection units, formed by the first straight line L1 and the second straight line L2 and the direction of rotation of magnet 30, is designated as the inter-detection unit angle θ. The inter-detection unit angle θ is the angle shown in the following formula (1). In the following formula (1), n ​​is the number of magnetic poles of magnet 30. Also, a is an odd number. Here, n is 16, and a is 1. Therefore, the inter-detection unit angle θ is 22.5°.

[0095] θ = 360° ÷ n × a……(1)

[0096] like Figures 3-7 As shown, the sensor housing 75 is formed from resin or the like into a plate extending radially. Additionally, the sensor housing 75 includes a cover pin 758, a first storage portion 751, and a second storage portion 752.

[0097] A cover pin 758 protrudes from the first base surface 761 toward the axial direction Da. The first receiving portion 751, formed as a bottomed cylindrical shape, receives the first magnetic detection portion 61, the second magnetic detection portion 62, and the first terminal 81 of the terminal 80 (described later). Furthermore, the first receiving portion 751 receives the substrate 60 with a portion of the substrate 60 exposed. The first receiving portion 751 includes a front end surface 753, a first base surface 761, and a second base surface 762. The front end surface 753 is formed in an arc shape. The front end surface 753 is radially opposed to the rotating body side surface 350. A space 754 is formed between the front end surface 753 and the rotating body side surface 350. The first base surface 761 is the surface of the first receiving portion 751 facing the axial direction Da. The second base surface 762 is the surface of the first receiving portion 751 facing the other side of the axial direction Da.

[0098] The second storage portion 752 is formed in the shape of a bottomed cylinder. Furthermore, the second storage portion 752 is radially connected to the first storage portion 751. Moreover, the second storage portion 752 houses the second terminal 82 of the terminal 80, which will be described later.

[0099] Terminal 80 has a first terminal 81 and a second terminal 82. The first terminal 81 extends axially along Da. A portion of the first terminal 81 is inserted into a hole in the substrate 60. The first terminal 81 is also connected to the substrate 60 by soldering. The second terminal 82 is connected to the first terminal 81 and extends radially. The second terminal 82 is also connected to the motor control device 18. Therefore, signals from the first magnetic detection unit 61 and the second magnetic detection unit 62 are output to the motor control device 18 via terminal 80.

[0100] The first cover 85 is formed of resin or the like. In addition, the first cover 85 has a first sensor cover portion 851 and a first rotating body cover portion 852.

[0101] The first sensor cover 851 is connected to a portion of the first base surface 761 by welding or bonding. Furthermore, the first sensor cover 851 covers the portion of the substrate 60 and the first terminal 81 that protrudes from the sensor housing 75. Moreover, the first sensor cover 851 has a pin hole 854. A portion of a cover pin 758 is inserted into the pin hole 854. Therefore, the first cover 85 is difficult to detach from the sensor housing 75. Additionally, by performing heat riveting or similar methods on the first sensor cover 851 and the cover pin 758, the first cover 85 is more difficult to detach from the sensor housing 75 compared to the case where heat riveting or similar methods are not performed. Alternatively, the first sensor cover 851 may have a cover pin 758, and the pin hole 854 may be formed on the first base surface 761 of the sensor housing 75.

[0102] The first rotating body cover 852 is connected to the first sensor cover 851. Furthermore, the first rotating body cover 852 and the first receiving portion 751 of the sensor housing 75 cover the first yoke annular portion 370. Moreover, the first rotating body cover 852 is formed in annular shape and includes a first cover hole 853. A portion of the rotating body 35 is inserted into this first cover hole 853 along the axial direction Da. This restricts the radial movement of the rotating body 35. Additionally, the first rotating body cover 852 is opposite the first yoke annular portion 370 along the axial direction Da. Therefore, the axial movement Da of the first yoke annular portion 370 is restricted, and the axial movement Da of the rotating body 35 is also restricted.

[0103] The second cover 86 is formed of resin or the like. In addition, the second cover 86 has a second sensor cover portion 861 and a second rotating body cover portion 862.

[0104] The second sensor cover 861 is connected to a portion of the second base surface 762 by welding or bonding. Furthermore, the second sensor cover 861 covers a portion of the first receiving portion 751 of the sensor housing 75. Moreover, a portion of a pin (not shown) protruding from the second base surface 762 of the sensor housing 75 is inserted into a hole (not shown) in the second sensor cover 861. Therefore, the second cover 86 is difficult to detach from the sensor housing 75. Furthermore, by heat-riveting the second sensor cover 861 and the pin (not shown), compared to the case without heat-riveting, the second cover 86 is more difficult to detach from the sensor housing 75. Alternatively, the second sensor cover 861 may have a pin (not shown) and a hole (not shown) formed on the second base surface 762 of the sensor housing 75.

[0105] The second rotating body cover 862 is connected to the second sensor cover 861. Furthermore, the second rotating body cover 862 and the first receiving portion 751 of the sensor housing 75 cover the second yoke annular portion 380. Moreover, the second rotating body cover 862 is formed in annular shape and includes a second cover hole 863. A portion of the rotating body 35 is inserted into this second cover hole 863 along the axial direction Da. This restricts the radial movement of the rotating body 35. Additionally, the second rotating body cover 862 is opposite the second yoke annular portion 380 along the axial direction Da. Therefore, the axial movement Da of the second yoke annular portion 380 is restricted, and the axial movement Da of the rotating body 35 is also restricted.

[0106] The torque sensor 25 is constituted as described above. Next, the detection of steering torque by the torque sensor 25 will be explained.

[0107] Assume that no steering torque is generated because steering wheel 5 is not rotated. In this case, such as Figure 12 As shown, the magnet 30, the first yoke claw 372, and the second yoke claw 382 are phase-matched in a neutral state in the circumferential direction. In this neutral state, the center positions of all the first yoke claws 372 and the second yoke claws 382 in the circumferential direction coincide with the boundaries of the N and S poles of the magnet 30. At this time, the number of magnetic field lines passing through the first yoke claw 372 from the N pole of the magnet 30 is the same as the number of magnetic field lines passing through the second yoke claw 382 from the N pole of the magnet 30. Therefore, no magnetic flux density is generated between the first yoke 361 and the second yoke 362.

[0108] Furthermore, when the steering wheel 5 is rotated, a steering torque is generated, thereby causing the first steering shaft 11 connected to the steering wheel 5 to rotate. Additionally, the torsion bar 13, fixed to the first steering shaft 11 via the pin 14, rotates. Furthermore, the second steering shaft 12, fixed to the torsion bar 13 via the pin 14, rotates. The second steering shaft 12 is connected to the fixing sleeve 354. Therefore, the rotating body 35 rotates. Consequently, the first yoke 361 and the second yoke 362, which are integral with the rotating body 35, rotate relative to the magnet 30.

[0109] In this case, such as Figure 13 As shown, the overlap between the N pole of magnet 30 and the first yoke claw 372 in the direction orthogonal to the axial direction Da increases. Additionally, the overlap between the S pole of magnet 30 and the second yoke claw 382 in the direction orthogonal to the axial direction Da also increases. At this time, the magnetic field lines from the N pole of magnet 30 toward the first yoke claw 372 increase, and the magnetic field lines from the second yoke claw 382 toward the S pole of magnet 30 increase. Therefore, a magnetic flux density is generated between the first yoke 361 and the second yoke 362.

[0110] Here, as described above, the first yoke annular portion 370 is opposed to the first magnetic detection portion 61 and the second magnetic detection portion 62 in the axial direction Da. Furthermore, the second yoke annular portion 380 is opposed to the first magnetic detection portion 61 and the second magnetic detection portion 62 in the axial direction Da.

[0111] Therefore, at this time, the magnetic field lines from the N pole of the magnet 30 increase through the first yoke ring portion 370 and passing through the first magnetic detection portion 61 and the second magnetic detection portion 62 respectively. Moreover, the magnetic field lines that have passed through the first magnetic detection portion 61 and the second magnetic detection portion 62 pass through the S pole of the magnet 30 through the second yoke ring portion 380.

[0112] Therefore, the first magnetic detection unit 61 and the second magnetic detection unit 62 detect the strength of the magnetic field in one direction of the axial direction Da. Consequently, the first magnetic detection unit 61 and the second magnetic detection unit 62 detect the steering torque. Furthermore, the first magnetic detection unit 61 and the second magnetic detection unit 62 output a signal corresponding to the detected magnetic field strength to the motor control device 18 via terminal 80.

[0113] Here, in the torque sensor 25, since it lacks a magnetic collecting section as described in Patent Document 1, the magnetic field leaking from the magnet 30 passes through the first magnetic detection section 61 and the second magnetic detection section 62. However, as described above, in the initial state, the first magnetic detection section 61 is radially opposed to the N pole of the magnet 30. Therefore, as... Figure 14 As shown, the magnetic field leaking from magnet 30 and passing through the first magnetic detection unit 61 includes an axial component Da and a component moving from the inside of the first magnetic detection unit 61 towards the outside. Furthermore, in the initial state, the second magnetic detection unit 62 is radially opposed to the S pole of magnet 30. Therefore, the magnetic field leaking from magnet 30 and passing through the second magnetic detection unit 62 includes an axial component Da and a component moving from the outside of the second magnetic detection unit 62 towards the inside. Therefore, the direction of the magnetic field detected by the second magnetic detection unit 62 in the magnetic field leaking from magnet 30 is opposite to the direction of the magnetic field detected by the first magnetic detection unit 61 in the magnetic field leaking from magnet 30. Furthermore, in Figure 14 In the diagram, the magnetic field lines that leak from the magnet 30 and pass through the first magnetic detection unit 61 and the second magnetic detection unit 62 are schematically represented by double-dotted lines.

[0114] Therefore, when the steering wheel 5, the rotating body 35, the first yoke 361, and the second yoke 362 rotate relative to the magnet 30, the noise detected by the first magnetic detection unit 61 and the second magnetic detection unit 62 is as follows: Figure 15 The results show that they cancel each other out. Furthermore, in Figure 15 In this diagram, the noise detected by the first magnetic detection unit 61 is represented by N1. The noise detected by the second magnetic detection unit 62 is represented by N2.

[0115] Therefore, the motor control device 18 calculates the sum of a value related to the strength of the magnetic field detected by the first magnetic detection unit 61 and a value related to the strength of the magnetic field detected by the second magnetic detection unit 62. As a result, the motor control device 18 removes noise based on the magnetic field leaking from the magnet 30. Furthermore, the motor control device 18 calculates the steering torque based on this calculated sum.

[0116] In addition, after producing with Figure 13 In the case of steering torque in the opposite direction, such as Figure 16 As shown, the overlap between the S pole of magnet 30 and the first yoke claw 372 in a direction orthogonal to the axial direction Da increases. Additionally, the overlap between the N pole of magnet 30 and the second yoke claw 382 in a direction orthogonal to the axial direction Da also increases. At this time, the magnetic field lines from the N pole of magnet 30 toward the second yoke claw 382 increase, and the magnetic field lines from the first yoke claw 372 toward the S pole of magnet 30 also increase. Therefore, a magnetic flux density is generated between the first yoke 361 and the second yoke 362.

[0117] Therefore, at this time, the magnetic field lines from the N pole of the magnet 30 increase through the second yoke ring portion 380, passing through the first magnetic detection portion 61 and the second magnetic detection portion 62 respectively. Moreover, the magnetic field lines that have passed through the first magnetic detection portion 61 and the second magnetic detection portion 62 pass through the S pole of the magnet 30 through the first yoke ring portion 370.

[0118] Therefore, the first magnetic detection unit 61 and the second magnetic detection unit 62 detect the strength of the magnetic field in another direction along the axial direction Da. Consequently, the first magnetic detection unit 61 and the second magnetic detection unit 62 detect the steering torque. Furthermore, the first magnetic detection unit 61 and the second magnetic detection unit 62 output a signal corresponding to the strength of the detected magnetic field to the motor control device 18 via terminal 80.

[0119] Furthermore, the motor control device 18 calculates, in the same manner as described above, the sum of a value related to the strength of the magnetic field detected by the first magnetic detection unit 61 and a value related to the strength of the magnetic field detected by the second magnetic detection unit 62. Thus, the motor control device 18 removes noise based on the magnetic field leaking from the magnet 30. Additionally, the motor control device 18 calculates the steering torque based on this calculated sum.

[0120] As described above, the torque sensor 25 detects the steering torque. Next, in the torque sensor 25 of the torque detection system of this embodiment, the magnetic collecting section described in Patent Document 1 can be removed. Furthermore, even if the relative positions of the first magnetic detection section 61 and the second magnetic detection section 62 relative to the first yoke 361 and the second yoke 362 shift, the tolerance to the noise magnetic field leaking from the magnet 30 is improved. These aspects will be explained below.

[0121] The torque detection system of this embodiment includes a torque sensor 25 and a motor control device 18. The torque sensor 25 has a magnet 30, a rotating body 35, a first yoke 361, a second yoke 362, a first magnetic detection unit 61, and a second magnetic detection unit 62. The magnet 30 generates a magnetic field and rotates together with the steering wheel 5 about an axis extending along the axial direction Da. The rotating body 35 is formed in a ring shape and rotates together with the steering wheel 5. The first yoke 361 includes a first yoke annular portion 370 and a first yoke claw portion 372. The first yoke annular portion 370 is formed in a ring shape and rotates together with the rotating body 35. The first yoke claw portion 372 protrudes from the first yoke annular portion 370 toward the axial direction Da and is radially opposed to the magnet 30, and collects the magnetic field generated by the magnet 30 by rotating together with the first yoke annular portion 370. The second yoke 362 has a second yoke annular portion 380 and a second yoke claw portion 382. The second yoke annular portion 380 is formed in a ring shape and rotates together with the rotating body 35. The second yoke claw portion 382 protrudes radially from the second yoke ring portion 380 toward the axial direction Da and is opposed to the magnet 30. It collects the magnetic field generated by the magnet 30 by rotating together with the second yoke ring portion 380. The first magnetic detection unit 61 overlaps with the first yoke ring portion 370 and the second yoke ring portion 380 projected along the axial direction Da. Furthermore, the first magnetic detection unit 61 detects the strength of the magnetic field that corresponds to the torque and changes due to the relative angle between the first yoke claw portion 372 and the second yoke claw portion 382 and the magnet 30 in the direction of rotation of the magnet 30. The second magnetic detection unit 62 overlaps with the first yoke ring portion 370 and the second yoke ring portion 380 projected along the axial direction Da. Furthermore, the second magnetic detection unit 62 detects the strength of a magnetic field that corresponds to the torque and varies by changing the relative angle between the first yoke claw portion 372 and the second yoke claw portion 382 and the magnet 30 in the rotational direction of the magnet 30. The motor control device 18 calculates the steering torque based on signals from the first magnetic detection unit 61 and the second magnetic detection unit 62. Additionally, in the initial state, the first magnetic detection unit 61 overlaps with the magnetic pole of the magnet 30 when projecting radially, for example, the N pole. Similarly, in the initial state, the second magnetic detection unit 62 overlaps with the magnetic pole of the magnet 30 when projecting radially, for example, the S pole, which is different from the magnetic pole of the magnet 30 overlapping with the first magnetic detection unit 61. The motor control device 18 calculates the sum of a value related to the strength of the magnetic field detected by the first magnetic detection unit 61 and a value related to the strength of the magnetic field detected by the second magnetic detection unit 62. The motor control device 18 then calculates the steering torque based on this sum. Furthermore, the steering wheel 5 corresponds to the detection object. The steering torque corresponds to the torque of the detection object. The first yoke 361 and the second yoke 362 correspond to the yoke. The first yoke annular portion 370 and the second yoke annular portion 380 correspond to the annular portion.The first yoke claw portion 372 and the second yoke claw portion 382 correspond to the claw portion. The radial direction corresponds to the direction orthogonal to the coaxial direction Da. The motor control device 18 corresponds to the arithmetic unit.

[0122] In the initial state, the second magnetic detection unit 62 overlaps with the magnetic pole of the magnet 30 projected radially when the magnetic pole of the magnet 30, which overlaps with the first magnetic detection unit 61, is different from that of the magnet 30. Therefore, the direction of the magnetic field detected by the second magnetic detection unit 62 in the magnetic field leaking from the magnet 30 is opposite to the direction of the magnetic field detected by the first magnetic detection unit 61 in the magnetic field leaking from the magnet 30. Thus, the noise detected by the first magnetic detection unit 61 and the second magnetic detection unit 62 cancels each other out. Furthermore, the motor control device 18 calculates the sum of a value related to the strength of the magnetic field detected by the first magnetic detection unit 61 and a value related to the strength of the magnetic field detected by the second magnetic detection unit 62. This removes the noise detected by the first magnetic detection unit 61 and the second magnetic detection unit 62. Therefore, even if the relative positions of the magnetic collecting unit, the first magnetic detection unit 61, and the second magnetic detection unit 62 relative to the first yoke 361 and the second yoke 362 shift after removal, the tolerance to the noise magnetic field leaking from the magnet 30 is improved.

[0123] Furthermore, assuming that the torque sensor 25 has a magnetic collecting section as described in Patent Document 1, the relative positions of the magnetic collecting section with respect to the first yoke 361, the second yoke 362, the first magnetic detection section 61, and the second magnetic detection section 62 may shift. In this case, the magnetic collecting section will not protect the first magnetic detection section 61 and the second magnetic detection section 62 from the magnetic field leaking from the magnet 30, and the magnetic field leaking from the magnet 30 will pass through the first magnetic detection section 61 and the second magnetic detection section 62. Therefore, in this case, the first magnetic detection section 61 and the second magnetic detection section 62 will detect the noisy magnetic field leaking from the magnet 30. However, in the torque sensor 25, even if the relative positions of the first magnetic detection section 61 and the second magnetic detection section 62 shift with respect to the first yoke 361 and the second yoke 362, the noise detected by the first magnetic detection section 61 and the second magnetic detection section 62 will cancel each other out. Moreover, the motor control device 18 calculates the sum of the value related to the strength of the magnetic field detected by the first magnetic detection section 61 and the value related to the strength of the magnetic field detected by the second magnetic detection section 62. Therefore, noise detected by the first magnetic detection unit 61 and the second magnetic detection unit 62 is removed. Consequently, the robustness of the first magnetic detection unit 61 and the second magnetic detection unit 62 relative to the relative positions of the first yoke 361 and the second yoke 362 is improved.

[0124] Furthermore, since the torque sensor 25 does not have the aforementioned magnetic collecting part, the size of the magnetic collecting part can be reduced by the amount that the torque sensor 25 is smaller.

[0125] In addition, the first embodiment also achieves the following effects.

[0126] [1-1] The first magnetic detection unit 61 and the second magnetic detection unit 62 are arranged on the same circle C centered on the axis of the magnet 30.

[0127] Therefore, the radial distance from magnet 30 to the first magnetic detection unit 61 and the radial distance from magnet 30 to the second magnetic detection unit 62 are easily made the same. Furthermore, the relative positions of the first magnetic detection unit 61 and the second magnetic detection unit 62 with respect to magnet 30 are easily made the same along the axial direction Da. Therefore, the strength of the magnetic field detected by the first magnetic detection unit 61 in the magnetic field leaking from magnet 30 and the strength of the magnetic field detected by the second magnetic detection unit 62 in the magnetic field leaking from magnet 30 are easily made the same. Therefore, the noise detected by the first magnetic detection unit 61 and the second magnetic detection unit 62 easily cancels each other out. Therefore, the noise detected by the first magnetic detection unit 61 and the second magnetic detection unit 62 is easily removed.

[0128] [1-2] The magnet 30 is magnetized by alternating reversals of its magnetic poles in the direction of rotation. Furthermore, the inter-detection angle θ is expressed as 360° ÷ n × a.

[0129] Therefore, in the initial state, the first magnetic detection unit 61 is easily positioned radially opposite only to the N pole of the magnet 30, and the second magnetic detection unit 62 is easily positioned radially opposite only to the S pole of the magnet 30. Consequently, the direction of the magnetic field detected by the second magnetic detection unit 62 in the magnetic field leaking from the magnet 30 is easily opposite to the direction of the magnetic field detected by the first magnetic detection unit 61 in the magnetic field leaking from the magnet 30. Therefore, the noise detected by the first magnetic detection unit 61 and the second magnetic detection unit 62 easily cancels each other out. Thus, the noise detected by the first magnetic detection unit 61 and the second magnetic detection unit 62 is easily removed.

[0130] [1-3] The magnet 30 is magnetized in such a way that the magnetic poles alternately reverse in the direction of rotation of the magnet 30. In addition, the number of magnetic poles of the magnet 30 is the same as the sum of the number of the first yoke claw portions 372 and the number of the second yoke claw portions 382. Furthermore, the sum of the number of the first yoke claw portions 372 and the number of the second yoke claw portions 382 corresponds to the number of claw portions.

[0131] As a result, the manufacture and management of magnet 30, first yoke 361 and second yoke 362 become easier.

[0132] (Second Implementation)

[0133] In the second embodiment, the arrangement of the first magnetic detection unit 61 and the second magnetic detection unit 62 differs from that in the first embodiment. Otherwise, it is the same as in the first embodiment.

[0134] like Figures 17-20As shown, the first magnetic detection unit 61 overlaps with the first yoke annular portion 370 projected when it is projected along the axial direction Da. Furthermore, the first magnetic detection unit 61 overlaps with the second yoke annular portion 380 projected when it is projected along the axial direction Da. Moreover, in the initial state, the first magnetic detection unit 61 overlaps with the N pole projected when the N pole of the magnet 30 is projected radially. Additionally, in the initial state, the first magnetic detection unit 61 does not overlap with the S pole projected when the S pole of the magnet 30 is projected radially.

[0135] The second magnetic detection unit 62 overlaps with the first yoke annular portion 370 projected when the first yoke annular portion 370 is projected along the axial direction Da. Furthermore, the second magnetic detection unit 62 overlaps with the second yoke annular portion 380 projected when the second yoke annular portion 380 is projected along the axial direction Da. Moreover, in the initial state, the second magnetic detection unit 62 overlaps with the N pole projected when the N pole of the magnet 30 is projected radially. Additionally, in the initial state, the second magnetic detection unit 62 does not overlap with the S pole projected when the S pole of the magnet 30 is projected radially. Alternatively, in the initial state, the first magnetic detection unit 61 and the second magnetic detection unit 62 may overlap with the S pole projected when the S pole of the magnet 30 is projected radially, but not with the N pole projected when the N pole of the magnet 30 is projected radially.

[0136] Here, the line passing through the center of the magnetic poles of magnet 30 and extending radially is designated as the center line Om. For example... Figure 19 and Figure 20 As shown, the radial distance from the N pole of magnet 30 to the first magnetic detection unit 61 is defined as the first magnet distance Lm1. The radial distance from the N pole of magnet 30 to the second magnetic detection unit 62 is defined as the second magnet distance Lm2. The distance from the center line Om to the axial distance Da of the first magnetic detection unit 61 is defined as the first inter-center distance La1. The distance from the center line Om to the axial distance Da of the second magnetic detection unit 62 is defined as the second inter-center distance La2.

[0137] Furthermore, the first magnetic detection unit 61 is positioned on the side closer to the axial direction Da than the center line Om. The second magnetic detection unit 62 is positioned on the other side closer to the axial direction Da than the center line Om. Moreover, the second magnetic detection unit 62 overlaps with the first magnetic detection unit 61 projected along the axial direction Da. Furthermore, the distance between the first magnets Lm1 and Lm2 is the same. Also, the distance between the first centers La1 and La2 is the same.

[0138] As described above, the torque sensor 25 constitutes the second embodiment. Next, in the second embodiment, the magnetic collecting section described in Patent Document 1 can also be removed from the torque sensor 25. Furthermore, even if the relative positions of the first magnetic detection section 61 and the second magnetic detection section 62 relative to the first yoke 361 and the second yoke 362 shift, the tolerance to noise magnetic fields leaking from the magnet 30 will be improved. These aspects will be explained below.

[0139] The torque detection system of this embodiment includes a torque sensor 25 and a motor control device 18. The torque sensor 25 has a magnet 30, a rotating body 35, a first yoke 361, a second yoke 362, a first magnetic detection unit 61, and a second magnetic detection unit 62. The magnet 30 generates a magnetic field and rotates together with the steering wheel 5 about an axis extending along the axial direction Da. The rotating body 35 is formed in a ring shape and rotates together with the steering wheel 5. The first yoke 361 includes a first yoke annular portion 370 and a first yoke claw portion 372. The first yoke annular portion 370 is formed in a ring shape and rotates together with the rotating body 35. The first yoke claw portion 372 protrudes from the first yoke annular portion 370 toward the axial direction Da and is radially opposed to the magnet 30, and collects the magnetic field generated by the magnet 30 by rotating together with the first yoke annular portion 370. The second yoke 362 has a second yoke annular portion 380 and a second yoke claw portion 382. The second yoke annular portion 380 is formed in a ring shape and rotates together with the rotating body 35. The second yoke claw portion 382 protrudes radially from the second yoke ring portion 380 toward the axial direction Da and is opposed to the magnet 30. It collects the magnetic field generated by the magnet 30 by rotating together with the second yoke ring portion 380. The first magnetic detection unit 61 overlaps with the first yoke ring portion 370 and the second yoke ring portion 380 projected along the axial direction Da. Furthermore, the first magnetic detection unit 61 detects the strength of the magnetic field, which corresponds to the torque and varies with the relative angle between the first yoke claw portion 372 and the second yoke claw portion 382 and the magnet 30 in the rotational direction of the magnet 30. The second magnetic detection unit 62 overlaps with the first yoke ring portion 370 and the second yoke ring portion 380 projected along the axial direction Da. Furthermore, the second magnetic detection unit 62 detects the strength of the magnetic field corresponding to the torque, which changes by varying the relative angle between the first yoke claw 372 and the second yoke claw 382 and the magnet 30 in the rotational direction of the magnet 30. The motor control device 18 calculates the steering torque based on signals from the first magnetic detection unit 61 and the second magnetic detection unit 62. In the initial state, the first magnetic detection unit 61 overlaps with the magnetic pole of the magnet 30 when projecting, for example, the N pole, radially. The first magnetic detection unit 61 is positioned on the side closer to the axial direction Da than the center line Om. Similarly, in the initial state, the second magnetic detection unit 62 overlaps with the magnetic pole of the magnet 30 that overlaps with the first magnetic detection unit 61 when projecting, for example, the N pole, radially. The second magnetic detection unit 62 is positioned on the other side closer to the axial direction Da than the center line Om. Furthermore, the motor control device 18 calculates the sum of a value related to the strength of the magnetic field detected by the first magnetic detection unit 61 and a value related to the strength of the magnetic field detected by the second magnetic detection unit 62. Additionally, the motor control device 18 calculates the steering torque based on this calculated sum.

[0140] In the initial state, the second magnetic detection unit 62 overlaps with the magnetic pole of the magnet 30 projected radially when the same magnetic pole as the magnetic pole of the magnet 30 overlapping with the first magnetic detection unit 61 is projected. Furthermore, the first magnetic detection unit 61 is positioned on the side closer to the axial direction Da than the center line Om. The second magnetic detection unit 62 is positioned on the other side closer to the axial direction Da than the center line Om. With these arrangements, the direction of the magnetic field detected by the second magnetic detection unit 62 in the magnetic field leaking from the magnet 30 is opposite to the direction of the magnetic field detected by the first magnetic detection unit 61 in the magnetic field leaking from the magnet 30. Therefore, the noise detected by the first magnetic detection unit 61 and the second magnetic detection unit 62 cancels each other out. Additionally, the motor control device 18 calculates the sum of a value related to the strength of the magnetic field detected by the first magnetic detection unit 61 and a value related to the strength of the magnetic field detected by the second magnetic detection unit 62. This removes the noise detected by the first magnetic detection unit 61 and the second magnetic detection unit 62. Therefore, even if the relative positions of the magnet collecting part, the first magnetic detection part 61 and the second magnetic detection part 62 relative to the first yoke 361 and the second yoke 362 are offset, the tolerance to the noise magnetic field leaking from the magnet 30 will be improved.

[0141] In addition, in the second embodiment, besides the effects described in [1-3] above, the following effects are also achieved.

[0142] [2-1] The distance Lm1 between the first magnet and the distance Lm2 between the second magnet are the same. Therefore, the strength of the magnetic field detected by the first magnetic detection unit 61 in the magnetic field leaking from the magnet 30 and the strength of the magnetic field detected by the second magnetic detection unit 62 in the magnetic field leaking from the magnet 30 are likely to be the same. Therefore, the noise detected by the first magnetic detection unit 61 and the second magnetic detection unit 62 can easily cancel each other out. Therefore, the noise detected by the first magnetic detection unit 61 and the second magnetic detection unit 62 can be easily removed.

[0143] [2-2] The first center-to-center distance La1 and the second center-to-center distance La2 are the same. Therefore, the strength of the magnetic field detected by the first magnetic detection unit 61 in the magnetic field leaking from the magnet 30 and the strength of the magnetic field detected by the second magnetic detection unit 62 in the magnetic field leaking from the magnet 30 are likely to be the same. Therefore, the noise detected by the first magnetic detection unit 61 and the second magnetic detection unit 62 can easily cancel each other out. Therefore, the noise detected by the first magnetic detection unit 61 and the second magnetic detection unit 62 can be easily removed.

[0144] (Third Implementation)

[0145] In the third embodiment, the shapes of the first yoke 361, the second yoke 362, the first magnetic detection unit 61, and the second magnetic detection unit 62 are different from those in the first embodiment. Apart from these differences, they are the same as in the first embodiment.

[0146] like Figures 21-25 As shown, in addition to the first yoke annular portion 370 and the first yoke claw portion 372, the first yoke 361 also has a first yoke flange portion 391.

[0147] The first yoke flange portion 391 is connected to the side of the first yoke annular portion 370 opposite to the first yoke claw portion 372. Furthermore, the first yoke flange portion 391 extends axially along Da from the boundary between the first yoke flange portion 391 and the first yoke annular portion 370. Moreover, the first yoke flange portion 391 is formed in a cylindrical shape.

[0148] In addition to the second yoke annular portion 380 and the second yoke claw portion 382, ​​the second yoke 362 also has a second yoke flange portion 392.

[0149] The second yoke flange portion 392 is connected to the side of the second yoke annular portion 380 opposite to the second yoke claw portion 382. Furthermore, the second yoke flange portion 392 extends axially along Da from the boundary between the second yoke flange portion 392 and the second yoke annular portion 380. Moreover, the second yoke flange portion 392 is formed in a cylindrical shape.

[0150] Here, the first magnetic detection unit 61 detects the strength of the radial magnetic field applied to it. Furthermore, the first magnetic detection unit 61 overlaps with the first yoke flange portion 391 projected radially. Also, the first magnetic detection unit 61 overlaps with the second yoke flange portion 392 projected radially. Additionally, in the initial state, the first magnetic detection unit 61 overlaps with the N pole projected radially from the N pole of the magnet 30. Furthermore, in the initial state, the first magnetic detection unit 61 does not overlap with the S pole projected radially from the S pole of the magnet 30.

[0151] Here, the second magnetic detection unit 62 detects the strength of the radial magnetic field applied to it. Furthermore, the second magnetic detection unit 62 overlaps with the first yoke flange 391 projected radially. Also, the second magnetic detection unit 62 overlaps with the second yoke flange 392 projected radially. Additionally, in the initial state, the second magnetic detection unit 62 overlaps with the S pole projected radially from the S pole of the magnet 30. Furthermore, in the initial state, the second magnetic detection unit 62 does not overlap with the N pole projected radially from the N pole of the magnet 30.

[0152] In addition, such as Figure 22As shown, the first magnetic detection unit 61 and the second magnetic detection unit 62 are arranged on the same circle C centered on the axis of the rotating body 35. Moreover, the angle θ between the detection units is the angle shown in the above-mentioned formula (1). In addition, the axial distance Da from the first yoke ring portion 370 to the first magnetic detection unit 61 is the same as the axial distance Da from the first yoke ring portion 370 to the second magnetic detection unit 62.

[0153] As described above, the torque sensor 25 constitutes the third embodiment. Next, the detection of steering torque by the torque sensor 25 of the third embodiment will be explained.

[0154] When the steering wheel 5 is rotated, the first yoke 361 and the second yoke 362 rotate relative to the magnet 30. At this time, it is assumed that the magnetic field lines from the N pole of the magnet 30 toward the first yoke claw 372 increase, and the magnetic field lines from the second yoke claw 382 toward the S pole of the magnet 30 increase.

[0155] In this case, the magnetic field lines from the N pole of the magnet 30 increase via the first yoke claw portion 372, the first yoke annular portion 370, and the first yoke flange portion 391, passing through the first magnetic detection portion 61 and the second magnetic detection portion 62, respectively. Furthermore, the magnetic field lines passing through the first magnetic detection portion 61 and the second magnetic detection portion 62 pass through the second yoke flange portion 392, the second yoke annular portion 380, and the second yoke claw portion 382, ​​passing through the S pole of the magnet 30.

[0156] Therefore, the first magnetic detection unit 61 and the second magnetic detection unit 62 detect the strength of the magnetic field in one of the radial directions. Consequently, the first magnetic detection unit 61 and the second magnetic detection unit 62 detect the steering torque. Furthermore, the first magnetic detection unit 61 and the second magnetic detection unit 62 output a signal corresponding to the detected magnetic field strength to the motor control device 18 via terminal 80.

[0157] Furthermore, it is assumed that the magnetic field lines increase from the N pole of the magnet 30 toward the second yoke claw 382, ​​and the magnetic field lines increase from the first yoke claw 372 toward the S pole of the magnet 30.

[0158] In this case, the magnetic field lines from the N pole of the magnet 30 increase via the second yoke claw portion 382, ​​the second yoke annular portion 380, and the second yoke flange portion 392, respectively, passing through the first magnetic detection portion 61 and the second magnetic detection portion 62. Furthermore, the magnetic field lines passing through the first magnetic detection portion 61 and the second magnetic detection portion 62 pass through the first yoke flange portion 391, the first yoke annular portion 370, and the first yoke claw portion 372, respectively, to the S pole of the magnet 30.

[0159] Therefore, the first magnetic detection unit 61 and the second magnetic detection unit 62 detect the strength of the magnetic field in another direction in the radial direction. Consequently, the first magnetic detection unit 61 and the second magnetic detection unit 62 detect the steering torque. Furthermore, the first magnetic detection unit 61 and the second magnetic detection unit 62 output a signal corresponding to the strength of the detected magnetic field to the motor control device 18 via terminal 80.

[0160] Furthermore, the motor control device 18 calculates, in the same manner as described above, the sum of a value related to the strength of the magnetic field detected by the first magnetic detection unit 61 and a value related to the strength of the magnetic field detected by the second magnetic detection unit 62. Thus, the motor control device 18 removes noise based on the magnetic field leaking from the magnet 30. Additionally, the motor control device 18 calculates the steering torque based on this calculated sum.

[0161] As described above, the torque sensor 25 detects the steering torque. This third embodiment achieves the same effect as the first embodiment.

[0162] (Fourth Implementation)

[0163] In the fourth embodiment, the shapes of the first yoke claw portion 372 and the second yoke claw portion 382 are different from those in the first embodiment, but otherwise they are the same as those in the first embodiment.

[0164] like Figures 26-28 As shown, the first yoke claw portion 372 has a first connecting portion 401 and a first protrusion 411.

[0165] The first connecting portion 401 is radially connected to the first yoke annular portion 370. Furthermore, in Figures 26-28 To avoid cluttering the illustrations, the description of the rotating body 35 is omitted. Furthermore, the first connecting portion 401 is inserted into the holes of the rotating body 35 formed at predetermined intervals along the circumference. Moreover, the first connecting portion 401 is radially connected to the first yoke ring portion 370, but this is not a limitation. For example, the first connecting portion 401 may also be axially connected to the first yoke ring portion 370 in the axial direction Da.

[0166] The first protrusion 411 connects to the side of the first connecting portion 401 opposite to the first yoke ring portion 370. Furthermore, the first protrusion 411 protrudes axially Da from its boundary with the first connecting portion 401. Moreover, the first protrusion 411 overlaps with the magnet 30 projected when the magnet 30 is projected radially. Additionally, similar to the first embodiment, since the first yoke claw portion 372 is connected to the inner surface of the rotating body 35, the first protrusion 411 is also connected to the inner surface of the rotating body 35.

[0167] Here, the surface passing through the center of the first protrusion 411 along the axial direction Da and orthogonal to the axial direction Da is designated as the first center surface Si1. Furthermore, the maximum length of the first protrusion 411 along the axial direction Da is designated as the first length Lc1. Moreover, as... Figure 26 As shown, the minimum distance along the axial direction Da from the first yoke ring portion 370 to the second yoke ring portion 380 is defined as the inter-yoke distance Lyb.

[0168] Moreover, returning Figures 26-28 The first protrusion 411 is symmetrical about the first center surface Si1 along the axial direction Da. Specifically, the first protrusion 411 is formed in a columnar shape. Furthermore, the first protrusion 411 includes a first bottom surface 421 and a first side surface 431. The first bottom surface 421 is formed in a polygonal, circular, or elliptical shape, etc., and here, for example, in a rectangular shape. Moreover, the first bottom surface 421 is orthogonal to the axial direction Da. The first side surface 431 is connected to the first bottom surface 421 and extends from the first bottom surface 421 along the axial direction Da. Therefore, the first protrusion 411 is formed in a quadrangular prism shape. Furthermore, all of the plurality of first protrusions 411 may be formed in a quadrangular prism shape, but this is not a limitation. At least one of the first protrusions 411 may also be formed in a quadrangular prism shape. Additionally, here, symmetry refers to linear symmetry or point symmetry. Moreover, the degree of symmetry includes the range of manufacturing tolerances.

[0169] Furthermore, the first length Lc1 is 30% or more of the interyoke distance Lyb. In addition, while the first length Lc1 is 30% or more of the interyoke distance Lyb in all of the plurality of first protrusions 411, it is not limited to this. Alternatively, the first length Lc1 may be 30% or more of the interyoke distance Lyb in at least one of the first protrusions 411.

[0170] like Figure 26 , Figure 29 and Figure 30 As shown, the second yoke portion 382 has a second connecting portion 402 and a second protrusion 412.

[0171] The second connecting portion 402 is radially connected to the second yoke annular portion 380. Furthermore, in Figure 29 and Figure 30 To avoid cluttering the illustrations, the description of the rotating body 35 is omitted. Furthermore, the second connecting portion 402 is inserted into the holes of the rotating body 35 formed at predetermined intervals along the circumference. Moreover, the second connecting portion 402 is radially connected to the second yoke ring portion 380, but this is not a limitation. For example, the second connecting portion 402 may also be axially connected to the second yoke ring portion 380 in the axial direction Da.

[0172] The second protrusion 412 connects to the side of the second connecting portion 402 opposite to the second yoke ring portion 380. Furthermore, the second protrusion 412 protrudes axially Da from its boundary with the second connecting portion 402. Moreover, the second protrusion 412 overlaps with the magnet 30 projected when the magnet 30 is projected radially. Additionally, similar to the first embodiment, since the second yoke claw portion 382 is connected to the inner surface of the rotating body 35, the second protrusion 412 is also connected to the inner surface of the rotating body 35. Furthermore, similar to the first embodiment, since the second yoke claw portion 382 is disposed between adjacent first yoke claw portions 372, the second protrusion 412 is disposed between adjacent first protrusions 411. Therefore, the first protrusions 411 and the second protrusion 412 are alternately arranged in the circumferential direction.

[0173] Furthermore, here, the surface that passes through the center of the second protrusion 412 on the axial direction Da and is orthogonal to the axial direction Da is designated as the second center surface Si2. Moreover, the maximum length of the second protrusion 412 on the axial direction Da is designated as the second length Lc2.

[0174] Furthermore, the second protrusion 412 is symmetrical about the second central surface Si2 along the axial direction Da. Specifically, the second protrusion 412 is formed in a columnar shape. Additionally, the second protrusion 412 includes a second bottom surface 422 and a second side surface 432. The second bottom surface 422 is formed in a polygonal, circular, or elliptical shape, etc., and here, for example, in a rectangular shape. Moreover, the second bottom surface 422 is orthogonal to the axial direction Da. The second side surface 432 is connected to the second bottom surface 422 and extends from the second bottom surface 422 along the axial direction Da. Therefore, the second protrusion 412 is formed in a quadrangular prism shape. Furthermore, all of the plurality of second protrusions 412 may be formed in a quadrangular prism shape, but this is not a limitation. It is also possible that at least one of the second protrusions 412 is formed in a quadrangular prism shape.

[0175] Furthermore, the second length Lc2 is 30% or more of the interyoke distance Lyb. In addition, in all of the plurality of second protrusions 412, the second length Lc2 is 30% or more of the interyoke distance Lyb, but this is not a limitation. Alternatively, in at least one of the second protrusions 412, the second length Lc2 may be 30% or more of the interyoke distance Lyb.

[0176] As described above, the torque sensor 25 constitutes the fourth embodiment. In this fourth embodiment, it achieves the same effects as the first embodiment. Furthermore, the fourth embodiment also achieves the effects described below.

[0177] [3-1] Here, as a comparative example, such as Figure 31As shown, assume that the first protrusion 411 is formed as a triangular prism with its bottom surface parallel to the axial direction Da. In this case, the first protrusion 411 is asymmetrical with respect to the first central plane Si1 along the axial direction Da. At this time, the size of the front end of the first protrusion 411, specifically the side of the first protrusion 411 opposite to the first yoke ring 370, is smaller than the size of the side of the first yoke ring 370. Therefore, the magnetic field leaking from the magnet 30 easily passes through the periphery of the front end of the first protrusion 411, resulting in a larger magnetic flux around the front end of the first protrusion 411 due to the magnetic field leaking from the magnet 30 compared to the magnetic flux around the side of the first yoke ring 370. Consequently, the magnetic flux distribution around the first protrusion 411 becomes asymmetrical with respect to the first central plane Si1. Thus, the deviation of the magnetic flux around the first protrusion 411 increases. Therefore, the magnetic field leaking from the magnet 30 easily passes through the area with larger magnetic flux around the first protrusion 411, specifically the area around the front end of the first protrusion 411, and then through the first magnetic detection unit 61 and the second magnetic detection unit 62. Thus, when the first protrusion 411 has an asymmetrical shape in the axial direction Da relative to the first center plane Si1, its tolerance to the noise magnetic field leaking from the magnet 30 is reduced.

[0178] In addition, as a comparative example, such as Figure 32 As shown, assume that the second protrusion 412 is formed as a triangular prism with its bottom surface parallel to the axial direction Da. In this case, the second protrusion 412 is asymmetrical with respect to the second central plane Si2 along the axial direction Da. At this time, the size of the front end of the second protrusion 412, specifically the side of the second protrusion 412 opposite to the second yoke ring 380, is smaller than the size of the side of the second yoke ring 380. Therefore, the magnetic field leaking from the magnet 30 easily passes through the periphery of the front end of the second protrusion 412, resulting in a larger magnetic flux around the front end of the second protrusion 412 due to the magnetic field leaking from the magnet 30 compared to the magnetic flux around the side of the second yoke ring 380. Therefore, the magnetic flux distribution around the second protrusion 412 becomes asymmetrical with respect to the second central plane Si2. Consequently, the deviation of the magnetic flux around the second protrusion 412 increases. Therefore, the magnetic field leaking from the magnet 30 easily passes through the area with larger magnetic flux around the second protrusion 412, specifically the area around the front end of the second protrusion 412, and then through the first magnetic detection unit 61 and the second magnetic detection unit 62. Therefore, when the second protrusion 412 has an asymmetrical shape relative to the second center plane Si2 in the axial direction Da, its tolerance to the noise magnetic field leaking from the magnet 30 is reduced.

[0179] In contrast, in the fourth embodiment, the first yoke claw portion 372 has a first connecting portion 401 and a first protrusion 411. The first connecting portion 401 is connected to the first yoke annular portion 370. The first protrusion 411 is connected to the first connecting portion 401 and protrudes from the first connecting portion 401 toward the axial direction Da. Furthermore, the second yoke claw portion 382 has a second connecting portion 402 and a second protrusion 412. The second connecting portion 402 is connected to the second yoke annular portion 380. The second protrusion 412 is connected to the second connecting portion 402 and protrudes from the second connecting portion 402 toward the axial direction Da. Moreover, the first connecting portion 401 and the second connecting portion 402 correspond to the connecting portion. Furthermore, the first protrusion 411 and the second protrusion 412 correspond to the protrusion.

[0180] Furthermore, the first protrusion 411 is symmetrical about the first center plane Si1 along the axial direction Da. In addition, the first center plane Si1 corresponds to the plane that passes through the center of the protrusion and is orthogonal to the axial direction Da.

[0181] Therefore, the magnetic flux distribution of the first protrusion 411 formed by the magnetic field leaking from the magnet 30 tends to be symmetrical with respect to the first central surface Si1. Consequently, the deviation of the magnetic flux around the first protrusion 411 is reduced. Therefore, the magnetic field leaking from the magnet 30 can be suppressed from passing through the first magnetic detection unit 61 and the second magnetic detection unit 62 via the portion with larger magnetic flux. Therefore, the magnetic field leaking from the magnet 30 is less likely to pass through the first magnetic detection unit 61 and the second magnetic detection unit 62 via the periphery of the first protrusion 411.

[0182] Furthermore, the second protrusion 412 is symmetrical about the second center plane Si2 along the axial direction Da. In addition, the second center plane Si2 corresponds to the plane that passes through the center of the protrusion and is orthogonal to the axial direction Da.

[0183] Therefore, the magnetic flux distribution of the second protrusion 412 formed by the magnetic field leaking from the magnet 30 is easily made symmetrical with respect to the second central plane Si2. Consequently, the deviation of the magnetic flux around the second protrusion 412 becomes smaller. Therefore, similarly, the magnetic field leaking from the magnet 30 is less likely to pass through the first magnetic detection unit 61 and the second magnetic detection unit 62 via the periphery of the second protrusion 412.

[0184] Therefore, as Figure 33 As shown, the intensity of the noise magnetic field detected by the first magnetic detection unit 61 and the second magnetic detection unit 62 in the fourth embodiment is smaller than that in the case where the first protrusion 411 and the second protrusion 412 are asymmetrical in the axial direction Da. Therefore, the tolerance to the noise magnetic field leaking from the magnet 30 is improved. Furthermore, in Figure 33In this embodiment, the intensity of the noise magnetic field when the first protrusion 411 and the second protrusion 412 are formed into a quadrangular prism shape and are symmetrical along the axial direction Da, as in the fourth embodiment, is denoted as Hns. Furthermore, the intensity of the noise magnetic field when the first protrusion 411 and the second protrusion 412 are formed into a triangular prism shape and are asymmetrical along the axial direction Da is denoted as Hna. Moreover, Hns and Hna are denoted for each distance when the first length Lc1 and the second length Lc2 are changed while the yoke distance Lyb is fixed at 9 mm.

[0185] [3-2] The first protrusion 411 is formed in a columnar shape. In addition, the first protrusion 411 includes a first bottom surface 421 and a first side surface 431. The first bottom surface 421 is orthogonal to the axial direction Da. The first side surface 431 is connected to the first bottom surface 421 and extends from the first bottom surface 421 along the axial direction Da.

[0186] Therefore, the first protrusion 411 is symmetrical about the first center plane Si1 along the axial direction Da. Thus, as described above, the tolerance to noisy magnetic fields leaking from the magnet 30 is improved.

[0187] Furthermore, the second protrusion 412 is formed in a columnar shape. Moreover, the second protrusion 412 includes a second bottom surface 422 and a second side surface 432. The second bottom surface 422 is orthogonal to the axial direction Da. The second side surface 432 is connected to the second bottom surface 422 and extends from the second bottom surface 422 along the axial direction Da.

[0188] Therefore, the second protrusion 412 is symmetrical about the second center plane Si2 along the axial direction Da. Thus, as described above, the tolerance to the noisy magnetic field leaking from the magnet 30 is improved.

[0189] [3-3] The first length Lc1 and the second length Lc2 are more than 30% of the interyoke distance Lyb.

[0190] Therefore, compared to when the first length Lc1 and the second length Lc2 are less than 30% of the interyoke distance Lyb, the first protrusion 411 and the second protrusion 412 easily shield the magnetic field leaking from the magnet 30. Thus, the magnetic field leaking from the magnet 30 is less likely to pass through the first magnetic detection unit 61 and the second magnetic detection unit 62. Therefore, the tolerance to noisy magnetic fields leaking from the magnet 30 is improved.

[0191] (Fifth Implementation)

[0192] In the fifth embodiment, the shapes of the first connecting portion 401, the first protrusion 411, the second connecting portion 402, and the second protrusion 412 differ from those in the fourth embodiment. Otherwise, they are the same as in the fourth embodiment.

[0193] like Figure 34As shown, the circumferential boundary portion of the boundary between the first bottom surface 421 and the first side surface 431 is R-shaped (rounded corner). However, it is not limited to the circumferential boundary portion of the boundary between the first bottom surface 421 and the first side surface 431 being R-shaped. At least one boundary portion of the boundary between the first bottom surface 421 and the first side surface 431 may be R-shaped. For example, the boundary portion of the first bottom surface 421 and the first side surface 431 adjacent to the circumferential boundary portion of the boundary between the first bottom surface 421 and the first side surface 431 may be R-shaped.

[0194] In addition, such as Figure 35 As shown, the boundary between the first connecting portion 401 and the first protrusion 411 is R-shaped. Furthermore, the corner of the first connecting portion 401 is R-shaped.

[0195] In addition, such as Figure 36 As shown, the circumferential boundary portion of the boundary between the second bottom surface 422 and the second side surface 432 is R-shaped. However, it is not limited to the circumferential boundary portion of the boundary between the second bottom surface 422 and the second side surface 432 being R-shaped. At least one boundary portion of the boundary between the second bottom surface 422 and the second side surface 432 may be R-shaped. For example, the boundary portion adjacent to the circumferential boundary portion of the boundary between the second bottom surface 422 and the second side surface 432 may be R-shaped.

[0196] Moreover, such as Figure 37 As shown, the boundary between the second connecting portion 402 and the second protrusion 412 is R-shaped. Additionally, the corner of the second connecting portion 402 is R-shaped.

[0197] As described above, the torque sensor 25 constitutes the fifth embodiment. In this fifth embodiment, it also achieves the same effect as the fourth embodiment.

[0198] (Sixth Implementation Method)

[0199] In the sixth embodiment, the shapes of the first connecting portion 401, the first protrusion 411, the second connecting portion 402, and the second protrusion 412 differ from those in the fourth embodiment. Otherwise, they are the same as in the fourth embodiment.

[0200] like Figure 38As shown, the circumferential boundary portion of the boundary between the first bottom surface 421 and the first side surface 431 is chamfered (C-shaped) to become an inclined surface relative to the first bottom surface 421 and the first side surface 431. Furthermore, it is not limited to the circumferential boundary portion of the boundary between the first bottom surface 421 and the first side surface 431 being an inclined surface relative to the first bottom surface 421 and the first side surface 431. At least one boundary portion of the boundary between the first bottom surface 421 and the first side surface 431 may be an inclined surface relative to the first bottom surface 421 and the first side surface 431. For example, the boundary portion adjacent to the circumferential boundary portion of the boundary between the first bottom surface 421 and the first side surface 431 may be an inclined surface relative to the first bottom surface 421 and the first side surface 431.

[0201] In addition, such as Figure 39 As shown, the boundary portions of the first connecting portion 401 and the first protrusion 411 are surfaces inclined relative to the extending direction of the first connecting portion 401 and the extending direction of the first protrusion 411. Furthermore, the corner portion of the first connecting portion 401 is a surface inclined relative to the extending direction of the first connecting portion 401.

[0202] In addition, such as Figure 40 As shown, the circumferential boundary portion of the boundary between the second bottom surface 422 and the second side surface 432 is chamfered (C-shaped) to become an inclined surface relative to the second bottom surface 422 and the second side surface 432. Furthermore, it is not limited to the circumferential boundary portion of the boundary between the second bottom surface 422 and the second side surface 432 being an inclined surface relative to the second bottom surface 422 and the second side surface 432. At least one boundary portion of the boundary between the second bottom surface 422 and the second side surface 432 may be an inclined surface relative to the second bottom surface 422 and the second side surface 432. For example, the boundary portion adjacent to the circumferential boundary portion of the boundary between the second bottom surface 422 and the second side surface 432 may be an inclined surface relative to the second bottom surface 422 and the second side surface 432.

[0203] Moreover, such as Figure 41 As shown, the boundary portions of the second connecting portion 402 and the second protrusion 412 are surfaces inclined relative to the extending direction of the second connecting portion 402 and the extending direction of the second protrusion 412. Additionally, the corner portions of the second connecting portion 402 are surfaces inclined relative to the extending direction of the second connecting portion 402.

[0204] As described above, the torque sensor 25 constitutes the sixth embodiment. In this sixth embodiment, it also achieves the same effect as the fourth embodiment.

[0205] (Seventh Implementation)

[0206] In the seventh embodiment, the shape of the magnet 30 differs from that in the first embodiment. Otherwise, it is the same as in the first embodiment.

[0207] Here, as Figure 42 As shown, the plane passing through the center of the magnet 30 along the axial direction Da and orthogonal to the axial direction Da is designated as the magnet center plane Sm. Furthermore, in Figure 42 To avoid making the illustrations too complicated, the description of the rotating body 35 is omitted.

[0208] Furthermore, the first magnetic detection unit 61 and the second magnetic detection unit 62 intersect with the center plane Sm of the magnet. Also, the first yoke claw 372 and the second yoke claw 382 intersect with the center plane Sm of the magnet.

[0209] Furthermore, the magnet 30 is formed such that the magnitude of its magnetic force increases from the center plane Sm towards the outer side of the axial direction Da. Therefore, the magnitude of the magnetic force at the portion of the magnet 30 that intersects with the center plane Sm is smaller than the magnitude of the magnetic force at the end of the magnet 30 facing the axial direction Da. Moreover, the magnitude of the magnetic force of the magnet 30 is measured using a Hall probe or similar method.

[0210] As described above, the torque sensor 25 constitutes the seventh embodiment. In this seventh embodiment, it achieves the same effects as the first embodiment. Furthermore, the seventh embodiment also achieves the effects described below.

[0211] [4] The first yoke claw portion 372 and the second yoke claw portion 382 intersect with the center plane Sm of the magnet. In addition, the magnitude of the magnetic force of the magnet 30 increases from the center plane Sm of the magnet toward the outer side of the axial direction Da.

[0212] Therefore, the magnitude of the magnetic force around the central surface Sm of the magnet is smaller than the magnitude of the magnetic force at the end of the magnet 30 facing the axial direction Da. Consequently, the magnetic field leaking from the magnet 30 is less likely to pass through the first magnetic detection unit 61 and the second magnetic detection unit 62 via the first yoke claw portion 372 and the second yoke claw portion 382, ​​which intersect with the central surface Sm of the magnet. Therefore, the tolerance to noisy magnetic fields leaking from the magnet 30 is improved.

[0213] (Eighth Implementation Method)

[0214] In the eighth embodiment, the shape of the magnet 30 differs from that in the seventh embodiment. Otherwise, it is the same as in the seventh embodiment.

[0215] Here, as Figure 43 As shown, the surface passing through the first magnetic detection unit 61 and orthogonal to the axis Da is designated as the through surface Sd. Alternatively, the through surface Sd can also be designated as the surface passing through the second magnetic detection unit 62 and orthogonal to the axis Da. Furthermore, in Figure 43 To avoid making the illustrations too complicated, the description of the rotating body 35 is omitted.

[0216] Furthermore, the magnet 30 intersects with the through surface Sd. Also, the first yoke claw portion 372 and the second yoke claw portion 382 intersect with the through surface Sd.

[0217] Furthermore, the magnet 30 is formed such that the magnitude of its magnetic force increases as it moves outward from the through surface Sd toward the axial direction Da. Therefore, the magnitude of the magnetic force at the portion of the magnet 30 that intersects with the through surface Sd is smaller than the magnitude of the magnetic force at the end of the magnet 30 facing the axial direction Da.

[0218] As described above, the torque sensor 25 constitutes the eighth embodiment. In this eighth embodiment, it also achieves the same effect as the seventh embodiment.

[0219] (Ninth Implementation)

[0220] In the ninth embodiment, the shape of the magnet 30 differs from that in the seventh embodiment. Otherwise, it is the same as in the seventh embodiment.

[0221] like Figure 44 As shown, the portion of magnet 30 that intersects with the central plane Sm of the magnet to a position located a predetermined distance outward from the axial direction Da is not magnetized. Therefore, the magnitude of the magnetic force at the portion of magnet 30 intersecting with the central plane Sm is smaller than the magnitude of the magnetic force at the end of magnet 30 facing the axial direction Da. Furthermore, the aforementioned predetermined distance is set, for example, based on the positional relationship or size of magnet 30, first yoke claw 372, second yoke claw 382, ​​first magnetic detection unit 61, and second magnetic detection unit 62. Additionally, in Figure 44 To avoid making the illustrations too complicated, the description of the rotating body 35 is omitted.

[0222] As described above, the torque sensor 25 constitutes the ninth embodiment. In this ninth embodiment, it also achieves the same effect as the seventh embodiment.

[0223] (Tenth Implementation)

[0224] In the tenth embodiment, the shape of the magnet 30 differs from that in the eighth embodiment. Otherwise, it is the same as in the eighth embodiment.

[0225] like Figure 45 As shown, the portion of magnet 30 that intersects with the through surface Sd and extends a predetermined distance outward from the axial direction Da is not magnetized. Therefore, the magnitude of the magnetic force at the portion of magnet 30 intersecting with the through surface Sd is smaller than the magnitude of the magnetic force at the end of magnet 30 facing the axial direction Da. Furthermore, in Figure 45 To avoid making the illustrations too complicated, the description of the rotating body 35 is omitted.

[0226] As described above, the torque sensor 25 constitutes the tenth embodiment. In this tenth embodiment, it also achieves the same effect as the eighth embodiment.

[0227] (Eleventh Implementation Method)

[0228] In the eleventh embodiment, the positions of the first magnetic detection unit 61 and the second magnetic detection unit 62 differ from those in the first embodiment. Otherwise, they are the same as in the first embodiment.

[0229] like Figure 46 As shown, the radially outer end of the first magnetic detection unit 61 is located radially inward of the radially outer end of the first yoke annular portion 370. Similarly, the radially inner end of the first magnetic detection unit 61 is located radially inward of the radially inner end of the first yoke annular portion 370. Therefore, the first magnetic detection unit 61 is located radially between the radially outer end and the radially inner end of the first yoke annular portion 370. Furthermore, the radially outer end of the first magnetic detection unit 61 is located radially inward of the radially outer end of the second yoke annular portion 380. Similarly, the radially inner end of the first magnetic detection unit 61 is located radially inward of the radially inner end of the second yoke annular portion 380. Therefore, the first magnetic detection unit 61 is located radially between the radially outer end and the radially inner end of the second yoke annular portion 380. Furthermore, the radially outer end of the first magnetic detection unit 61 corresponds to the end of the first magnetic detection unit 61 on the side opposite to the magnet 30. Additionally, the radially inner end of the first magnetic detection unit 61 corresponds to the end of the first magnetic detection unit 61 on the magnet 30 side. Similarly, the radially outer end of the first yoke ring portion 370 corresponds to the end of the first yoke ring portion 370 on the side opposite to the magnet 30. Furthermore, the radially inner end of the first yoke ring portion 370 corresponds to the end of the first yoke ring portion 370 on the magnet 30 side. Likewise, the radially outer end of the second yoke ring portion 380 corresponds to the end of the second yoke ring portion 380 on the side opposite to the magnet 30. Additionally, the radially inner end of the second yoke ring portion 380 corresponds to the end of the second yoke ring portion 380 on the magnet 30 side.

[0230] Furthermore, similar to the first magnetic detection unit 61, the radially outer end of the second magnetic detection unit 62 is located radially inward of the radially outer end of the first yoke annular portion 370. Moreover, the radially inner end of the second magnetic detection unit 62 is located radially inward of the radially inner end of the first yoke annular portion 370. Therefore, the second magnetic detection unit 62 is located radially between the radially outer end and the radially inner end of the first yoke annular portion 370. Additionally, the radially outer end of the second magnetic detection unit 62 is located radially inward of the radially outer end of the second yoke annular portion 380. Moreover, the radially inner end of the second magnetic detection unit 62 is located radially inward of the radially inner end of the second yoke annular portion 380. Therefore, the second magnetic detection unit 62 is located radially between the radially outer end and the radially inner end of the second yoke annular portion 380. Furthermore, the radially outer end of the second magnetic detection unit 62 corresponds to the end of the second magnetic detection unit 62 on the side opposite to the magnet 30. Additionally, the radially inner end of the second magnetic detection unit 62 corresponds to the end of the second magnetic detection unit 62 on the magnet 30 side.

[0231] As described above, the torque sensor 25 constitutes the eleventh embodiment. In this eleventh embodiment, it also achieves the same effect as the first embodiment.

[0232] (Twelfth Implementation)

[0233] In the twelfth embodiment, the positions of the first magnetic detection unit 61 and the second magnetic detection unit 62 differ from those in the second embodiment. Otherwise, they are the same as in the second embodiment.

[0234] like Figure 47 As shown, the radially outer end of the first magnetic detection unit 61 is located radially inward of the radially outer end of the first yoke annular portion 370. Similarly, the radially inner end of the first magnetic detection unit 61 is located radially inward of the radially inner end of the first yoke annular portion 370. Therefore, the first magnetic detection unit 61 is located radially between the radially outer end and the radially inner end of the first yoke annular portion 370. Furthermore, the radially outer end of the first magnetic detection unit 61 is located radially inward of the radially outer end of the second yoke annular portion 380. Similarly, the radially inner end of the first magnetic detection unit 61 is located radially inward of the radially inner end of the second yoke annular portion 380. Therefore, the first magnetic detection unit 61 is located radially between the radially outer end and the radially inner end of the second yoke annular portion 380.

[0235] Furthermore, the radially outer end of the second magnetic detection unit 62 is located radially inward of the radially outer end of the first yoke annular portion 370. Additionally, the radially inner end of the second magnetic detection unit 62 is located radially inward of the radially inner end of the first yoke annular portion 370. Therefore, the second magnetic detection unit 62 is located radially between the radially outer end and the radially inner end of the first yoke annular portion 370. Moreover, the radially outer end of the second magnetic detection unit 62 is located radially inward of the radially outer end of the second yoke annular portion 380. Additionally, the radially inner end of the second magnetic detection unit 62 is located radially inward of the radially inner end of the second yoke annular portion 380. Therefore, the second magnetic detection unit 62 is located radially between the radially outer end and the radially inner end of the second yoke annular portion 380.

[0236] As described above, the torque sensor 25 constitutes the twelfth embodiment. In this twelfth embodiment, it also achieves the same effect as the second embodiment.

[0237] (Thirteenth Implementation Method)

[0238] In the thirteenth embodiment, the positions of the first magnetic detection unit 61 and the second magnetic detection unit 62 differ from those in the third embodiment. Otherwise, they are the same as in the third embodiment.

[0239] like Figure 48 As shown, the outer edge of the first magnetic detection unit 61 is located in the axial direction Da between the end of the first yoke flange 391 outside the axial direction Da and the boundary between the second yoke annular portion 380 and the second yoke flange 392. Similarly, the outer edge of the first magnetic detection unit 61 is located in the axial direction Da between the end of the second yoke flange 392 outside the axial direction Da and the boundary between the second yoke annular portion 380 and the second yoke flange 392.

[0240] Furthermore, similar to the first magnetic detection unit 61, the outer edge of the second magnetic detection unit 62 is located in the axial direction Da between the end of the first yoke flange 391 outside the axial direction Da and the boundary between the second yoke annular portion 380 and the second yoke flange 392. Additionally, the outer edge of the second magnetic detection unit 62 is located in the axial direction Da between the end of the second yoke flange 392 outside the axial direction Da and the boundary between the second yoke annular portion 380 and the second yoke flange 392.

[0241] As described above, the torque sensor 25 constitutes the thirteenth embodiment. In this thirteenth embodiment, it also achieves the same effect as the third embodiment.

[0242] (Other implementation methods)

[0243] This disclosure is not limited to the above-described embodiments, and appropriate modifications can be made to the above-described embodiments. In addition, in each of the above-described embodiments, the elements constituting the embodiments are not necessarily essential, except where they are specifically stated to be necessary or are obviously considered necessary in principle.

[0244] The arithmetic unit and methods described in this disclosure can also be implemented using a special-purpose computer provided by means of a processor and memory programmed to perform one or more functions embodied in a computer program. Alternatively, the arithmetic unit and methods described in this disclosure can also be implemented using a special-purpose computer provided by means of a processor composed of one or more special-purpose hardware logic circuits. Alternatively, the arithmetic unit and methods described in this disclosure can also be implemented using one or more special-purpose computers composed of a processor and memory programmed to perform one or more functions and a processor composed of one or more hardware logic circuits. Furthermore, the computer program can also be stored as instructions executable by the computer on a computer-readable non-transitional tangible recording medium.

[0245] In the embodiments described above, the magnet 30 is formed in a circular ring shape. However, the magnet 30 is not limited to being formed in a circular ring shape. For example, the magnet 30 may also be formed in a polygonal ring shape, etc.

[0246] In the embodiments described above, the rotating body 35 is formed in a cylindrical shape. However, the rotating body 35 is not limited to being formed in a cylindrical shape. For example, the rotating body 35 may also be formed in a polygonal cylindrical shape or an elliptical cylindrical shape.

[0247] In the above embodiments, the first yoke annular portion 370 and the second yoke annular portion 380 are formed in a circular shape. However, the first yoke annular portion 370 and the second yoke annular portion 380 are not limited to being formed in a circular shape. For example, the first yoke annular portion 370 and the second yoke annular portion 380 may also be formed in a polygonal annular shape, etc.

[0248] In the above embodiments, the first yoke claw portion 372 and the second yoke claw portion 382 are pointed. In contrast, the first yoke claw portion 372 and the second yoke claw portion 382 are not limited to being pointed. For example, the first yoke claw portion 372 and the second yoke claw portion 382 may also be rectangular or the like.

[0249] In the above embodiments, the fixing sleeve 354 is connected to the second steering shaft 12, and the magnet 30 is connected to the first steering shaft 11. However, this is not limited to the fixing sleeve 354 being connected to the second steering shaft 12 and the magnet 30 being connected to the first steering shaft 11. For example, the fixing sleeve 354 may be connected to the first steering shaft 11, and the magnet 30 may be connected to the second steering shaft 12.

[0250] In the above embodiments, the motor control device 18 calculates the steering torque based on signals from the first magnetic detection unit 61 and the second magnetic detection unit 62. However, it is not limited to the motor control device 18 calculating the steering torque based on signals from the first magnetic detection unit 61 and the second magnetic detection unit 62. Alternatively, a different calculation unit from the motor control device 18 may calculate the steering torque based on signals from the first magnetic detection unit 61 and the second magnetic detection unit 62.

[0251] The above-described embodiments can also be combined appropriately.

[0252] (Features of this disclosure)

[0253] [First Viewpoint]

[0254] A torque detection system for detecting torque generated by a detection object, wherein the system comprises:

[0255] A torque sensor (25) includes a magnet (30), a rotating body (35), a yoke (361, 362), a first magnetic detection unit (61), and a second magnetic detection unit (62). The magnet generates a magnetic field and rotates together with the object being detected about an axis extending along an axial direction (Da). The rotating body is annular and rotates together with the object being detected. The yoke includes annular portions (370, 380) and claw portions (372, 382). The annular portions are annular and rotate together with the rotating body. The claw portions extend from the annular portions toward the axial direction and interact with the magnet in a direction orthogonal to the axial direction. Opposite, and by rotating together with the annular portion to focus the magnetic field generated by the magnet, the first magnetic detection unit overlaps with the annular portion projected when the annular portion is projected along the axial direction, and detects the strength of the magnetic field corresponding to the torque and varying by changing the relative angle of the yoke with respect to the magnet in the rotational direction of the magnet; the second magnetic detection unit overlaps with the annular portion projected when the annular portion is projected along the axial direction, and detects the strength of the magnetic field corresponding to the torque and varying by changing the relative angle of the yoke with respect to the magnet in the rotational direction of the magnet; and

[0256] The calculation unit (18) calculates the torque based on signals from the first magnetic detection unit and the second magnetic detection unit;

[0257] When the first magnetic detection unit does not generate the torque, it overlaps with the magnetic poles of the magnet projected when the magnetic poles (N, S) of the magnet are projected in a direction orthogonal to the axial direction.

[0258] When the second magnetic detection unit does not generate the torque, it overlaps with the magnetic poles of the magnet projected when the magnetic poles (S, N) of the magnet that are different from the magnetic poles of the magnet overlapping with the first magnetic detection unit are projected in a direction orthogonal to the axial direction.

[0259] The calculation unit calculates the sum of a value related to the strength of the magnetic field detected by the first magnetic detection unit and a value related to the strength of the magnetic field detected by the second magnetic detection unit, and calculates the torque based on the calculated sum.

[0260] [Second Viewpoint]

[0261] According to the torque detection system described in the first point of view, wherein...

[0262] The first magnetic detection unit and the second magnetic detection unit are arranged on the same circle (C) centered on the axis of the magnet.

[0263] [Third Viewpoint]

[0264] According to the torque detection system described in the first or second viewpoint, wherein...

[0265] The magnet is magnetized in such a way that the magnetic poles alternately reverse in the direction of rotation of the magnet.

[0266] If we define the number of magnetic poles of the magnet as n, and the odd number as a,

[0267] The angle (θ) of the rotation direction of the magnet, formed by the line (L1) connecting the axis of the magnet and the first magnetic detection unit and the line (L2) connecting the axis of the magnet and the second magnetic detection unit, is an angle represented by 360°÷n×a.

[0268] [Fourth viewpoint]

[0269] According to the torque detection system described in the first or second viewpoint, wherein...

[0270] The magnet is magnetized in such a way that the magnetic poles alternately reverse in the direction of rotation of the magnet.

[0271] The number of magnetic poles of the magnet is the same as the number of claws.

[0272] [Fifth Viewpoint]

[0273] A torque detection system for detecting torque generated by a detection object, wherein the system comprises:

[0274] A torque sensor (25) includes a magnet (30), a rotating body (35), a yoke (361, 362), a first magnetic detection unit (61), and a second magnetic detection unit (62). The magnet generates a magnetic field and rotates together with the object being detected about an axis extending along an axial direction (Da). The rotating body is annular and rotates together with the object being detected. The yoke includes annular portions (370, 380) and claw portions (372, 382). The annular portions are annular and rotate together with the rotating body. The claw portions extend from the annular portions toward the axial direction and interact with the magnet in a direction orthogonal to the axial direction. Opposite, and by rotating together with the annular portion to focus the magnetic field generated by the magnet, the first magnetic detection unit overlaps with the annular portion projected when the annular portion is projected along the axial direction, and detects the strength of the magnetic field corresponding to the torque and varying by changing the relative angle of the yoke with respect to the magnet in the rotational direction of the magnet; the second magnetic detection unit overlaps with the annular portion projected when the annular portion is projected along the axial direction, and detects the strength of the magnetic field corresponding to the torque and varying by changing the relative angle of the yoke with respect to the magnet in the rotational direction of the magnet; and

[0275] The calculation unit (18) calculates the torque based on signals from the first magnetic detection unit and the second magnetic detection unit;

[0276] When the first magnetic detection unit is not generating the torque, it overlaps with the magnetic poles of the magnet projected when the magnetic poles (N, S) of the magnet are projected in a direction orthogonal to the axial direction, and is positioned on the side of the axial direction closer to the center line (Om) extending in a direction orthogonal to the axial direction than the center line passing through the center of the magnetic poles of the magnet.

[0277] When the second magnetic detection unit is not generating the torque, it overlaps with the magnetic poles of the magnet projected when the same magnetic poles (N, S) of the magnet overlapping with the first magnetic detection unit are projected in a direction orthogonal to the axial direction, and is positioned on the opposite side of the axial direction from the center line.

[0278] The calculation unit calculates the sum of a value related to the strength of the magnetic field detected by the first magnetic detection unit and a value related to the strength of the magnetic field detected by the second magnetic detection unit, and calculates the torque based on the calculated sum.

[0279] [Sixth Viewpoint]

[0280] A torque detection system for detecting torque generated by a detection object, wherein the system comprises:

[0281] A torque sensor (25) has a magnet (30), a rotating body (35), a yoke (361, 362), a first magnetic detection unit (61), and a second magnetic detection unit (62). The magnet generates a magnetic field and rotates together with the object being detected about an axis extending along an axial direction (Da). The rotating body is annular and rotates together with the object being detected. The yoke includes annular portions (370, 380), claw portions (372, 382), and flange portions (391, 392). The annular portions are annular and rotate together with the rotating body. The claw portions are positioned opposite the magnet in a direction orthogonal to the axial direction by protruding from the annular portions toward the axial direction, and are also positioned by... The annular portion rotates together to collect the magnetic field generated by the magnet. The flange portion protrudes from the annular portion toward the axial direction. The first magnetic detection unit overlaps with the flange portion projected when projected in a direction orthogonal to the axial direction, and detects the strength of the magnetic field corresponding to the torque and varying by changing the relative angle of the yoke with respect to the magnet in the rotational direction of the magnet. The second magnetic detection unit overlaps with the flange portion projected when projected in a direction orthogonal to the axial direction, and detects the strength of the magnetic field corresponding to the torque and varying by changing the relative angle of the yoke with respect to the magnet in the rotational direction of the magnet; and

[0282] The calculation unit (18) calculates the torque based on signals from the first magnetic detection unit and the second magnetic detection unit;

[0283] When the first magnetic detection unit does not generate the torque, it overlaps with the magnetic poles of the magnet projected when the magnetic poles (N, S) of the magnet are projected in a direction orthogonal to the axial direction.

[0284] When the second magnetic detection unit does not generate the torque, it overlaps with the magnetic poles of the magnet projected when the magnetic poles (S, N) of the magnet that are different from the magnetic poles of the magnet overlapping with the first magnetic detection unit are projected in a direction orthogonal to the axial direction.

[0285] The calculation unit calculates the sum of a value related to the strength of the magnetic field detected by the first magnetic detection unit and a value related to the strength of the magnetic field detected by the second magnetic detection unit, and calculates the torque based on the calculated sum.

[0286] [Seventh Viewpoint]

[0287] According to any one of the first to sixth viewpoints, in the torque detection system, wherein,

[0288] The claw portion has a connecting portion (401, 402) connected to the annular portion and a protrusion (411, 412) connected to the connecting portion and protruding from the connecting portion toward the axial direction.

[0289] The protrusion is symmetrical about the axial direction relative to the planes (Si1, Si2) that pass through the center of the protrusion and are orthogonal to the axial direction.

[0290] [Eighth Viewpoint]

[0291] According to the torque detection system described in the seventh point, wherein...

[0292] The protrusion is formed in a columnar shape, including a bottom surface (421, 422) and a side surface (431, 432).

[0293] The bottom surface is orthogonal to the axis.

[0294] The side surface is connected to the bottom surface and extends from the bottom surface along the axial direction.

[0295] [Ninth Viewpoint]

[0296] According to any one of the first to sixth viewpoints, in the torque detection system, wherein,

[0297] The claw portion has a connecting portion (401, 402) connected to the annular portion and a protrusion (411, 412) connected to the connecting portion and protruding from the connecting portion toward the axial direction.

[0298] The protrusion is formed in a columnar shape, including a bottom surface (421, 422) and a side surface (431, 432).

[0299] The bottom surface is orthogonal to the axis.

[0300] The side surface is connected to the bottom surface and extends from the bottom surface along the axial direction.

[0301] At least one of the boundary portions of the bottom surface and the side surface is R-shaped.

[0302] [Tenth Viewpoint]

[0303] According to any one of the first to sixth viewpoints, in the torque detection system, wherein,

[0304] The claw portion has a connecting portion (401, 402) connected to the annular portion and a protrusion (411, 412) connected to the connecting portion and protruding from the connecting portion toward the axial direction.

[0305] The protrusion is formed in a columnar shape, including a bottom surface (421, 422) and a side surface (431, 432).

[0306] The bottom surface is orthogonal to the axis.

[0307] The side surface is connected to the bottom surface and extends from the bottom surface along the axial direction.

[0308] At least one of the boundary portions of the bottom surface and the side surface is an inclined surface relative to the bottom surface and the side surface.

[0309] [Eleventh Viewpoint]

[0310] According to any one of the first to sixth viewpoints, in the torque detection system, wherein,

[0311] The annular portion is the first annular portion (370).

[0312] The claw portion is the first claw portion (372).

[0313] The yoke also includes a second annular portion (380) and a second claw portion (382).

[0314] The second annular portion rotates together with the rotating body.

[0315] The second claw protrudes from the second annular portion toward the axial direction and is positioned opposite the magnet in a direction orthogonal to the axial direction, and concentrates the magnetic field generated by the magnet by rotating together with the second annular portion.

[0316] The first annular portion and the second annular portion are opposite each other in the axial direction.

[0317] The first claw portion has a first connecting portion (401) connected to the first annular portion and a first protrusion (411) connected to the first connecting portion and protruding from the first connecting portion toward the axial direction.

[0318] The second claw portion has a second connecting portion (402) connected to the second annular portion and a second protrusion (412) connected to the second connecting portion and protruding from the second connecting portion toward the axial direction.

[0319] The lengths (Lc1, Lc2) of the first and second protrusions along the axial direction are more than 30% of the axial distance (Lyb) from the first annular portion to the second annular portion.

[0320] [Twelfth Viewpoint]

[0321] According to any one of the first to eleventh viewpoints, the torque detection system wherein...

[0322] The claw intersects with the magnet center plane (Sm), which passes through the center of the magnet along the axial direction and is orthogonal to the axial direction.

[0323] The magnitude of the magnetic force of the magnet increases as it moves outward from the center plane of the magnet toward the axial direction.

[0324] [Thirteenth Viewpoint]

[0325] According to any one of the first to eleventh viewpoints, the torque detection system wherein...

[0326] The claw intersects with the surface (Sd) that passes through the first magnetic detection unit and is orthogonal to the axis.

[0327] The magnet intersects with the through surface.

[0328] The magnitude of the magnetic force of the magnet increases as it moves outward from the through surface toward the axial direction.

[0329] [Fourteenth Viewpoint]

[0330] According to any one of the first to eleventh viewpoints, the torque detection system wherein...

[0331] The claw intersects with the magnet center plane (Sm), which passes through the center of the magnet along the axial direction and is orthogonal to the axial direction.

[0332] The portion of the magnet that intersects with the central plane of the magnet is not magnetized.

[0333] [Fifteenth Viewpoint]

[0334] According to any one of the first to eleventh viewpoints, the torque detection system wherein...

[0335] The claw intersects with the surface (Sd) that passes through the first magnetic detection unit and is orthogonal to the axis.

[0336] The magnet intersects with the through surface.

[0337] The portion of the magnet that intersects with the through surface is not magnetized.

Claims

1. A torque detection system for detecting torque generated by a detection object, characterized in that, have: A torque sensor includes a magnet, a rotating body, a yoke, a first magnetic detection unit, and a second magnetic detection unit. The magnet generates a magnetic field and rotates with the object being detected about an axis extending along the axial direction. The rotating body is annular and rotates with the object being detected. The yoke includes an annular portion and a claw portion. The annular portion is annular and rotates with the rotating body. The claw portion protrudes from the annular portion toward the axial direction and is positioned opposite the magnet in a direction orthogonal to the axial direction. It collects the magnetic field generated by the magnet by rotating with the annular portion. The first magnetic detection unit overlaps with the annular portion projected along the axial direction and detects the strength of the magnetic field corresponding to the torque and varying by changing the relative angle of the yoke relative to the magnet in the direction of rotation of the magnet. The second magnetic detection unit overlaps with the annular portion projected along the axial direction and detects the strength of the magnetic field corresponding to the torque and varying by changing the relative angle of the yoke relative to the magnet in the direction of rotation of the magnet. as well as The calculation unit calculates the torque based on signals from the first magnetic detection unit and the second magnetic detection unit; When the first magnetic detection unit does not generate the torque, it overlaps with the magnetic poles of the magnet projected when the magnetic poles of the magnet are projected in a direction orthogonal to the axial direction. When the second magnetic detection unit does not generate the torque, it overlaps with the magnetic pole of the magnet projected when the magnetic pole of the magnet overlapping with the first magnetic detection unit is projected in a direction orthogonal to the axial direction. The arithmetic unit calculates the sum of a value related to the strength of the magnetic field detected by the first magnetic detection unit and a value related to the strength of the magnetic field detected by the second magnetic detection unit, and calculates the torque based on the calculated sum. The torque sensor does not have a magnetic collecting part that guides the magnetic field, which varies through the yoke, to the first magnetic detection unit and the second magnetic detection unit.

2. The torque detection system according to claim 1, characterized in that, The first magnetic detection unit and the second magnetic detection unit are arranged on the same circle centered on the axis of the magnet.

3. The torque detection system according to claim 1, characterized in that, The magnet is magnetized in such a way that the magnetic poles alternately reverse in the direction of rotation of the magnet. If we define the number of magnetic poles of the magnet as n, and the odd number as a, The angle of rotation of the magnet, formed by the line connecting the axis of the magnet and the first magnetic detection unit and the line connecting the axis of the magnet and the second magnetic detection unit, is an angle represented by 360°÷n×a.

4. The torque detection system according to claim 1, characterized in that, The magnet is magnetized in such a way that the magnetic poles alternately reverse in the direction of rotation of the magnet. The number of magnetic poles of the magnet is the same as the number of claws.

5. The torque detection system according to claim 1, characterized in that, The claw portion has a connecting portion connected to the annular portion and a protrusion connected to the connecting portion and protruding from the connecting portion toward the axial direction. The protrusion is symmetrical about the axial direction relative to the surface passing through the center of the protrusion and orthogonal to the axial direction.

6. The torque detection system according to claim 5, characterized in that, The protrusion is formed in a columnar shape, including a bottom surface and a side surface. The bottom surface is orthogonal to the axis. The side surface is connected to the bottom surface and extends from the bottom surface along the axial direction.

7. The torque detection system according to claim 1, characterized in that, The claw portion has a connecting portion connected to the annular portion and a protrusion connected to the connecting portion and protruding from the connecting portion toward the axial direction. The protrusion is formed in a columnar shape, including a bottom surface and a side surface. The bottom surface is orthogonal to the axis. The side surface is connected to the bottom surface and extends from the bottom surface along the axial direction. At least one of the boundary portions of the bottom surface and the side surface is R-shaped.

8. The torque detection system according to claim 1, characterized in that, The claw portion has a connecting portion connected to the annular portion and a protrusion connected to the connecting portion and protruding from the connecting portion toward the axial direction. The protrusion is formed in a columnar shape, including a bottom surface and a side surface. The bottom surface is orthogonal to the axis. The side surface is connected to the bottom surface and extends from the bottom surface along the axial direction. At least one of the boundary portions of the bottom surface and the side surface is an inclined surface relative to the bottom surface and the side surface.

9. The torque detection system according to claim 1, characterized in that, The annular portion is the first annular portion. The claw portion is the first claw portion. The yoke also includes a second annular portion and a second claw portion. The second annular portion rotates together with the rotating body. The second claw protrudes from the second annular portion toward the axial direction and is positioned opposite the magnet in a direction orthogonal to the axial direction, and concentrates the magnetic field generated by the magnet by rotating together with the second annular portion. The first annular portion and the second annular portion are opposite each other in the axial direction. The first claw portion has a first connecting portion connected to the first annular portion and a first protrusion connected to the first connecting portion and protruding from the first connecting portion toward the axial direction. The second claw portion has a second connecting portion connected to the second annular portion and a second protrusion connected to the second connecting portion and protruding from the second connecting portion toward the axial direction. The lengths of the first and second protrusions along the axial direction are more than 30% of the axial distance from the first annular portion to the second annular portion.

10. The torque detection system according to any one of claims 1 to 9, characterized in that, The claw intersects with the center plane of the magnet, which passes through the center of the magnet along the axial direction and is orthogonal to the axial direction. The magnitude of the magnetic force of the magnet increases as it moves outward from the center plane of the magnet toward the axial direction.

11. The torque detection system according to any one of claims 1 to 9, characterized in that, The claw intersects with the surface that passes through the first magnetic detection part and is orthogonal to the axial direction. The magnet intersects with the through surface. The magnitude of the magnetic force of the magnet increases as it moves outward from the through surface toward the axial direction.

12. The torque detection system according to any one of claims 1 to 9, characterized in that, The claw intersects with the center plane of the magnet, which passes through the center of the magnet along the axial direction and is orthogonal to the axial direction. The portion of the magnet that intersects with the central plane of the magnet is not magnetized.

13. The torque detection system according to any one of claims 1 to 9, characterized in that, The claw intersects with the surface that passes through the first magnetic detection part and is orthogonal to the axial direction. The magnet intersects with the through surface. The portion of the magnet that intersects with the through surface is not magnetized.

14. A torque detection system for detecting torque generated by a detection object, characterized in that, have: A torque sensor includes a magnet, a rotating body, a yoke, a first magnetic detection unit, and a second magnetic detection unit. The magnet generates a magnetic field and rotates with the object being detected about an axis extending along the axial direction. The rotating body is annular and rotates with the object being detected. The yoke includes an annular portion and a claw portion. The annular portion is annular and rotates with the rotating body. The claw portion protrudes from the annular portion toward the axial direction and is positioned opposite the magnet in a direction orthogonal to the axial direction. It collects the magnetic field generated by the magnet by rotating with the annular portion. The first magnetic detection unit overlaps with the annular portion projected along the axial direction and detects the strength of the magnetic field corresponding to the torque and varying by changing the relative angle of the yoke relative to the magnet in the direction of rotation of the magnet. The second magnetic detection unit overlaps with the annular portion projected along the axial direction and detects the strength of the magnetic field corresponding to the torque and varying by changing the relative angle of the yoke relative to the magnet in the direction of rotation of the magnet. as well as The calculation unit calculates the torque based on signals from the first magnetic detection unit and the second magnetic detection unit; When the first magnetic detection unit is not generating the torque, it overlaps with the magnetic poles of the magnet projected when the magnetic poles of the magnet are projected in a direction orthogonal to the axial direction, and is positioned on the side closer to the axial direction than the center line extending in a direction orthogonal to the axial direction that passes through the center of the magnetic poles of the magnet. When the second magnetic detection unit is not generating the torque, it overlaps with the magnetic pole of the magnet projected when the same magnetic pole as the magnetic pole of the magnet overlapping with the first magnetic detection unit is projected in a direction orthogonal to the axial direction, and is positioned on the opposite side of the axial direction from the center line. The calculation unit calculates the sum of a value related to the strength of the magnetic field detected by the first magnetic detection unit and a value related to the strength of the magnetic field detected by the second magnetic detection unit, and calculates the torque based on the calculated sum.

15. The torque detection system according to claim 14, characterized in that, The claw portion has a connecting portion connected to the annular portion and a protrusion connected to the connecting portion and protruding from the connecting portion toward the axial direction. The protrusion is symmetrical about the axial direction relative to the surface passing through the center of the protrusion and orthogonal to the axial direction.

16. The torque detection system according to claim 15, characterized in that, The protrusion is formed in a columnar shape, including a bottom surface and a side surface. The bottom surface is orthogonal to the axis. The side surface is connected to the bottom surface and extends from the bottom surface along the axial direction.

17. The torque detection system according to claim 14, characterized in that, The claw portion has a connecting portion connected to the annular portion and a protrusion connected to the connecting portion and protruding from the connecting portion toward the axial direction. The protrusion is formed in a columnar shape, including a bottom surface and a side surface. The bottom surface is orthogonal to the axis. The side surface is connected to the bottom surface and extends from the bottom surface along the axial direction. At least one of the boundary portions of the bottom surface and the side surface is R-shaped.

18. The torque detection system according to claim 14, characterized in that, The claw portion has a connecting portion connected to the annular portion and a protrusion connected to the connecting portion and protruding from the connecting portion toward the axial direction. The protrusion is formed in a columnar shape, including a bottom surface and a side surface. The bottom surface is orthogonal to the axis. The side surface is connected to the bottom surface and extends from the bottom surface along the axial direction. At least one of the boundary portions of the bottom surface and the side surface is an inclined surface relative to the bottom surface and the side surface.

19. The torque detection system according to claim 14, characterized in that, The annular portion is the first annular portion. The claw portion is the first claw portion. The yoke also includes a second annular portion and a second claw portion. The second annular portion rotates together with the rotating body. The second claw protrudes from the second annular portion toward the axial direction and is positioned opposite the magnet in a direction orthogonal to the axial direction, and concentrates the magnetic field generated by the magnet by rotating together with the second annular portion. The first annular portion and the second annular portion are opposite each other in the axial direction. The first claw portion has a first connecting portion connected to the first annular portion and a first protrusion connected to the first connecting portion and protruding from the first connecting portion toward the axial direction. The second claw portion has a second connecting portion connected to the second annular portion and a second protrusion connected to the second connecting portion and protruding from the second connecting portion toward the axial direction. The lengths of the first and second protrusions along the axial direction are more than 30% of the axial distance from the first annular portion to the second annular portion.

20. The torque detection system according to any one of claims 14 to 19, characterized in that, The claw intersects with the center plane of the magnet, which passes through the center of the magnet along the axial direction and is orthogonal to the axial direction. The magnitude of the magnetic force of the magnet increases as it moves outward from the center plane of the magnet toward the axial direction.

21. The torque detection system according to any one of claims 14 to 19, characterized in that, The claw intersects with the surface that passes through the first magnetic detection part and is orthogonal to the axial direction. The magnet intersects with the through surface. The magnitude of the magnetic force of the magnet increases as it moves outward from the through surface toward the axial direction.

22. The torque detection system according to any one of claims 14 to 19, characterized in that, The claw intersects with the center plane of the magnet, which passes through the center of the magnet along the axial direction and is orthogonal to the axial direction. The portion of the magnet that intersects with the central plane of the magnet is not magnetized.

23. The torque detection system according to any one of claims 14 to 19, characterized in that, The claw intersects with the surface that passes through the first magnetic detection part and is orthogonal to the axial direction. The magnet intersects with the through surface. The portion of the magnet that intersects with the through surface is not magnetized.

24. A torque detection system for detecting torque generated in a detection object, characterized in that, have: A torque sensor includes a magnet, a rotating body, a yoke, a first magnetic detection unit, and a second magnetic detection unit. The magnet generates a magnetic field and rotates together with the object being detected about an axially extending axis. The rotating body is annular and rotates together with the object being detected. The yoke includes an annular portion, a claw portion, and a flange portion. The annular portion is annular and rotates together with the rotating body. The claw portion protrudes from the annular portion toward the axial direction and is positioned opposite the magnet in a direction orthogonal to the axial direction, and concentrates the magnetic field generated by the magnet by rotating together with the annular portion. The flange portion... The first magnetic detection unit overlaps with the flange portion projected when the flange portion is projected in a direction orthogonal to the axial direction, and detects the strength of a magnetic field that corresponds to the torque and changes by changing the relative angle of the yoke with respect to the magnet in the rotational direction of the magnet; the second magnetic detection unit overlaps with the flange portion projected when the flange portion is projected in a direction orthogonal to the axial direction, and detects the strength of a magnetic field that corresponds to the torque and changes by changing the relative angle of the yoke with respect to the magnet in the rotational direction of the magnet. as well as The calculation unit calculates the torque based on signals from the first magnetic detection unit and the second magnetic detection unit; When the first magnetic detection unit does not generate the torque, it overlaps with the magnetic poles of the magnet projected when the magnetic poles of the magnet are projected in a direction orthogonal to the axial direction. When the second magnetic detection unit does not generate the torque, it overlaps with the magnetic pole of the magnet projected when the magnetic pole of the magnet overlapping with the first magnetic detection unit is projected in a direction orthogonal to the axial direction. The calculation unit calculates the sum of a value related to the strength of the magnetic field detected by the first magnetic detection unit and a value related to the strength of the magnetic field detected by the second magnetic detection unit, and calculates the torque based on the calculated sum.

25. The torque detection system according to claim 24, characterized in that, The claw portion has a connecting portion connected to the annular portion and a protrusion connected to the connecting portion and protruding from the connecting portion toward the axial direction. The protrusion is symmetrical about the axial direction relative to the surface passing through the center of the protrusion and orthogonal to the axial direction.

26. The torque detection system according to claim 25, characterized in that, The protrusion is formed in a columnar shape, including a bottom surface and a side surface. The bottom surface is orthogonal to the axis. The side surface is connected to the bottom surface and extends from the bottom surface along the axial direction.

27. The torque detection system according to claim 24, characterized in that, The claw portion has a connecting portion connected to the annular portion and a protrusion connected to the connecting portion and protruding from the connecting portion toward the axial direction. The protrusion is formed in a columnar shape, including a bottom surface and a side surface. The bottom surface is orthogonal to the axis. The side surface is connected to the bottom surface and extends from the bottom surface along the axial direction. At least one of the boundary portions of the bottom surface and the side surface is R-shaped.

28. The torque detection system according to claim 24, characterized in that, The claw portion has a connecting portion connected to the annular portion and a protrusion connected to the connecting portion and protruding from the connecting portion toward the axial direction. The protrusion is formed in a columnar shape, including a bottom surface and a side surface. The bottom surface is orthogonal to the axis. The side surface is connected to the bottom surface and extends from the bottom surface along the axial direction. At least one of the boundary portions of the bottom surface and the side surface is an inclined surface relative to the bottom surface and the side surface.

29. The torque detection system according to claim 24, characterized in that, The annular portion is the first annular portion. The claw portion is the first claw portion. The yoke also includes a second annular portion and a second claw portion. The second annular portion rotates together with the rotating body. The second claw protrudes from the second annular portion toward the axial direction and is positioned opposite the magnet in a direction orthogonal to the axial direction, and concentrates the magnetic field generated by the magnet by rotating together with the second annular portion. The first annular portion and the second annular portion are opposite each other in the axial direction. The first claw portion has a first connecting portion connected to the first annular portion and a first protrusion connected to the first connecting portion and protruding from the first connecting portion toward the axial direction. The second claw portion has a second connecting portion connected to the second annular portion and a second protrusion connected to the second connecting portion and protruding from the second connecting portion toward the axial direction. The lengths of the first and second protrusions along the axial direction are more than 30% of the axial distance from the first annular portion to the second annular portion.

30. The torque detection system according to any one of claims 24 to 29, characterized in that, The claw intersects with the center plane of the magnet, which passes through the center of the magnet along the axial direction and is orthogonal to the axial direction. The magnitude of the magnetic force of the magnet increases as it moves outward from the center plane of the magnet toward the axial direction.

31. The torque detection system according to any one of claims 24 to 29, characterized in that, The claw intersects with the surface that passes through the first magnetic detection part and is orthogonal to the axial direction. The magnet intersects with the through surface. The magnitude of the magnetic force of the magnet increases as it moves outward from the through surface toward the axial direction.

32. The torque detection system according to any one of claims 24 to 29, characterized in that, The claw intersects with the center plane of the magnet, which passes through the center of the magnet along the axial direction and is orthogonal to the axial direction. The portion of the magnet that intersects with the central plane of the magnet is not magnetized.

33. The torque detection system according to any one of claims 24 to 29, characterized in that, The claw intersects with the surface that passes through the first magnetic detection part and is orthogonal to the axial direction. The magnet intersects with the through surface. The portion of the magnet that intersects with the through surface is not magnetized.

Images