JP2017015696A - Relative angle detection device, torque sensor, electrically-driven power steering device and vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a relative angle detection device that is suitable for enlarging a torque detection range, and to provide a torque sensor, electrically-driven power steering device and vehicle that include the relative angle detection device.SOLUTION: On the basis of a first sign expressing sin(θ+Δθ) corresponding to a rotation angle θof a first multi-polar magnet 10 rotating in synchronization with an input axis 22a of the input axis 22a and an output axis 22b coaxially arranged, and a first cosine signal expressing cos(θ+Δθ), and a second sign expressing sinθcorresponding to a rotation angle θof a second multi-polar magnet 11 rotating in synchronization with the output axis 22b, and a second cosine signal expressing cosθ, sinΔθ and cosΔθ are computed that correspond to a relative angle Δθ between the input axis 22a and output axis 22b, and the relative angle Δθ is computed from Δθ=arctan(sinΔθ/cosΔθ).SELECTED DRAWING: Figure 6

Description

  The present invention relates to a relative angle detection device, a torque sensor, an electric power steering device, and a vehicle.

Conventionally, multipolar ring magnets are respectively arranged at both ends of the torsion bar, magnetic flux corresponding to the rotational displacement of these multipolar ring magnets is detected by a magnetic sensor, and a torsion angle is calculated from the detected magnetic flux. As a technique for detecting the torque value, for example, there is a technique disclosed in Patent Document 1.
In this technique, each of the multipolar ring magnets is provided with two magnetic sensors having a phase difference of 90 ° in electrical angle, and sin Δθ (square value addition value Z) with respect to the torsion angle from the outputs of the total four magnetic sensors. And the torque value is detected from this sin Δθ.

JP 2013-24638 A

However, the conventional technique of Patent Document 1 calculates only sin Δθ (square value addition value Z) and uses the straight line portion as a torque value. This is because the torsion angle cannot be uniquely calculated in the torsion angle region exceeding the linear portion of sin Δθ. Therefore, there exists a subject that the area | region exceeding a linear part cannot be utilized as a torque detection range.
Therefore, the present invention has been made paying attention to such an unsolved problem of the conventional technology, and a relative angle detection device suitable for expanding a torque detection range, and this relative angle detection device An object of the present invention is to provide a torque sensor, an electric power steering device, and a vehicle.

In order to achieve the above object, a relative angle detection device according to a first aspect of the present invention includes a first rotation shaft and a second rotation in which different magnetic poles are alternately arranged in the circumferential direction and arranged coaxially. Among the shafts, first multipolar ring magnets that rotate in synchronization with the first rotation shaft, and magnetic poles that are different in the circumferential direction are alternately arranged, and the second rotation shaft of the first rotation shaft and the second rotation shaft. A second multi-pole ring magnet that rotates synchronously with the first multi-pole ring magnet, and a first sine signal that represents sin θ ₁ and a first cosine signal that represents cos θ ₁ by detecting magnetic flux according to the rotation angle θ ₁ of the first multi-pole ring magnet. A first rotation angle sensor that outputs, a second sine signal that represents sin θ ₂ and a second cosine signal that represents cos θ ₂ by detecting magnetic flux according to the rotation angle θ ₂ of the second multipolar ring magnet. Two rotation angle sensor and the first sine signal And sin Δθ and cos Δθ corresponding to a relative angle Δθ between the first rotating shaft and the second rotating shaft are calculated based on the first cosine signal, the second sine signal, and the second cosine signal, and Δθ = Arctan (sinΔθ / cosΔθ) and a relative angle calculation unit that calculates the relative angle Δθ.

In addition, the torque sensor according to the second aspect of the present invention detects the relative angle Δθ between the input shaft and the output shaft connected by the torsion bar by the relative angle detection device according to the first aspect, and the relative angle thereof. A torque calculator is provided for calculating torque generated on the input shaft and the output shaft from Δθ.
An electric power steering apparatus according to the third aspect of the present invention includes the torque sensor according to the second aspect.
A vehicle according to a fourth aspect of the present invention includes the electric power steering device according to the third aspect.

  According to the present invention, the relative angle Δθ is calculated by calculating sin Δθ and cos Δθ according to the relative angle Δθ, and calculating the arc tangent of the value obtained by dividing the calculated sin Δθ by cos Δθ. Thus, for example, when applied to a torque sensor, it is possible to calculate torque even in a torsional angle region exceeding the linear portion of sin Δθ. As a result, it is possible to deal with a wider torque detection range. Further, since the entire information of sin Δθ can be utilized even in the same torque detection range, the resolution of the detected torque value can be increased. Further, since the relative angle Δθ can be calculated by a single calculation such as calculating arctan (sin Δθ / cos Δθ), a more accurate torque value can be calculated.

1 is a block diagram illustrating a configuration example of a vehicle according to a first embodiment of the present invention. It is a perspective view showing typically one example of composition of the 1st sensor part of the 1st relative angle detector concerning a 1st embodiment of the present invention. (A) is the figure which looked at the 1st sensor part of the 1st relative angle detection device concerning a 1st embodiment of the present invention from the front, and (b) is an AA sectional view of (a). (C) is BB sectional drawing of (a). It is a figure showing an example of 1 composition of the 1st torque sensor concerning a 1st embodiment of the present invention. (A) is a waveform diagram showing sin θ _is , and (b) is a waveform diagram showing cos θ _is . It is a block diagram which shows the example of 1 structure of the relative angle calculating part which concerns on 1st Embodiment of this invention. (A) is a waveform diagram showing sin Δθ, and (b) is a waveform diagram showing cos Δθ. It is a figure which shows the relationship between an input twist angle and the calculated twist angle (relative angle (DELTA) (theta)). It is a figure which shows one structural example of the 2nd sensor part of the 2nd relative angle detection apparatus which concerns on 2nd Embodiment of this invention. It is a perspective view which shows one structural example of the 3rd sensor part of the 3rd relative angle detection apparatus which concerns on 3rd Embodiment of this invention. (A) is the schematic diagram which looked at the 3rd sensor part of the 3rd relative angle detection device concerning a 1st embodiment of the present invention from the front, and (b) is a CC section of (a). FIG. 4C is a sectional view taken along the line DD of FIG. It is a figure which shows one structural example of the 3rd torque sensor which concerns on 3rd Embodiment of this invention. (A) is a perspective view which shows one structural example of the 4th sensor part of the 4th relative angle detection apparatus which concerns on 4th Embodiment of this invention, (b) is the 1st sign of (a). FIG. 4 is a partial axial sectional view including an optical sensor 64. It is a figure which shows the example of 1 structure of the 4th torque sensor which concerns on 4th Embodiment of this invention. (A) is a perspective view which shows one structural example of the 5th sensor part of the 5th relative angle detection apparatus which concerns on 5th Embodiment of this invention, (b) is 5th rotation of (a). It is the top view which looked at the angle sensor from the surface side, (c) is the top view which looked at the 5th rotation angle sensor of (a) from the back surface side. It is a figure which shows the example of 1 structure of the 5th torque sensor which concerns on 5th Embodiment of this invention. (A) is a perspective view which shows one structural example of the 6th sensor part of the 6th relative angle detection apparatus which concerns on 6th Embodiment of this invention, (b) is the 7th rotation of (a). It is the top view which looked at the angle sensor from the curved surface side, (c) is the top view which looked at the 7th rotation angle sensor of (a) from the surface on the opposite side to a curved surface. It is a figure which shows one structural example of the 6th torque sensor which concerns on 6th Embodiment of this invention.

Next, first to sixth embodiments of the present invention will be described with reference to the drawings. In the following description of the drawings, the same or similar parts are denoted by the same or similar reference numerals. However, it should be noted that the drawings are schematic, and the vertical and horizontal dimensions and scales of members and parts are different from actual ones. Therefore, specific dimensions and scales should be determined in consideration of the following description. Moreover, it is a matter of course that portions having different dimensional relationships and ratios are included between the drawings.
In addition, the following first to sixth embodiments exemplify apparatuses and methods for embodying the technical idea of the present invention, and the technical idea of the present invention is the material of components, The shape, structure, arrangement, etc. are not specified below. The technical idea of the present invention can be variously modified within the technical scope defined by the claims described in the claims.

(First embodiment)
(Constitution)
As shown in FIG. 1, the vehicle 3 according to the first embodiment includes front wheels 3FR and 3FL and rear wheels 3RR and 3RL which are left and right steered wheels. The front wheels 3FR and 3FL are steered by the electric power steering device 2.

As shown in FIG. 1, the electric power steering apparatus 2 includes a steering wheel 21, a steering shaft 22, a first torque sensor 1, a first universal joint 24, a lower shaft 25, and a second universal joint. 26.
The electric power steering apparatus 2 further includes a pinion shaft 27, a steering gear 28, a tie rod 29, and a knuckle arm 30.

The steering force applied to the steering wheel 21 from the driver is transmitted to the steering shaft 22. The steering shaft 22 has an input shaft 22a and an output shaft 22b. One end of the input shaft 22 a is connected to the steering wheel 21, and the other end is connected to one end of the output shaft 22 b via the first torque sensor 1.
The steering force transmitted to the output shaft 22 b is transmitted to the lower shaft 25 via the first universal joint 24 and further transmitted to the pinion shaft 27 via the second universal joint 26. The steering force transmitted to the pinion shaft 27 is transmitted to the tie rod 29 via the steering gear 28. Further, the steering force transmitted to the tie rod 29 is transmitted to the knuckle arm 30 to steer the front wheels 3FR and 3FL.

Here, the steering gear 28 is configured in a rack and pinion type having a pinion 28a coupled to the pinion shaft 27 and a rack 28b meshing with the pinion 28a. Accordingly, the steering gear 28 converts the rotational motion transmitted to the pinion 28a into a straight motion in the vehicle width direction by the rack 28b.
Further, a steering assist mechanism 31 that transmits a steering assist force to the output shaft 22b is connected to the output shaft 22b of the steering shaft 22.

The steering assist mechanism 31 is fixed to a housing of the electric motor 33, a reduction gear 32 configured by, for example, a worm gear mechanism connected to the output shaft 22 b, an electric motor 33 that generates a steering assist force connected to the reduction gear 32, and the electric motor 33. A supported EPS control unit 34 is provided.
The electric motor 33 is a three-phase brushless motor, and includes an annular motor rotor and an annular motor stator (not shown). The motor stator includes a plurality of pole teeth protruding radially inward at equal intervals in the circumferential direction, and an excitation coil is wound around each pole tooth. A motor rotor is coaxially disposed inside the motor stator. The motor rotor includes a plurality of magnets which are opposed to the pole teeth of the motor stator with a slight gap (air gap) and are provided on the outer peripheral surface at equal intervals in the circumferential direction.

The motor rotor is fixed to the motor rotation shaft, and by passing a three-phase alternating current through the motor control coil through the EPS control unit 34, each tooth of the motor stator is excited in a predetermined order to rotate the motor rotor. A motor rotating shaft rotates with rotation.
Although not shown, the EPS control unit 34 includes a current command calculation circuit and a motor drive circuit. Further, as shown in FIG. 1, the EPS control unit 34 receives a vehicle speed V detected by the vehicle speed sensor 35 and a direct current from a battery 36 as a direct current voltage source.

The current command calculation circuit is a current for driving the electric motor 33 based on the vehicle speed V from the vehicle speed sensor 35, the steering torque Ts from the first torque sensor 1, and the motor rotation angle θm from the electric motor 33. Calculate the command value.
The motor drive circuit is composed of, for example, a three-phase inverter circuit, and drives the electric motor 33 based on the current command value from the current command calculation circuit.

The first torque sensor 1 detects a steering torque Ts applied to the steering wheel 21 and transmitted to the input shaft 22a.
Specifically, as shown in FIGS. 2 and 4, the first torque sensor 1 includes a first relative angle detection device 100 and a torque calculation unit 19.
The first relative angle detection device 100 includes a first sensor unit 101 and a relative angle calculation unit 18.

As shown in FIG. 2, the first sensor unit 101 includes a first multipolar ring magnet 10 and a second multipolar ring magnet 11, and a torsion bar 22c made of an elastic member such as spring steel. Yes.
Further, the first sensor unit 101 includes a first rotation angle sensor 12 provided on the radially outer side of the first multipole ring magnet 10 and detecting a rotation angle of the first multipole ring magnet 10, and a second multipole ring magnet 10. And a second rotation angle sensor 13 for detecting a rotation angle of the second multipolar ring magnet 11 provided on the radially outer side of the pole ring magnet 11.

In the first embodiment, the first multipolar ring magnet 10 is attached to the end of the input shaft 22a on the output shaft 22b side (ideally, the connection position of the torsion bar 22c) so as to be able to rotate synchronously with the input shaft 22a. Further, the second multipolar ring magnet 11 is attached to the end of the output shaft 22b on the input shaft 22a side (ideally, the connecting position of the torsion bar 22c) so as to be able to rotate synchronously with the output shaft 22b.
In addition, the first multipolar ring magnet 10 and the second multipolar ring magnet 11 of the first embodiment magnetize, for example, a portion of the outer peripheral surface of the magnetic ring to one of the S and N poles at equal intervals. Can be obtained.

Specifically, the first multipolar ring magnet 10 and the second multipolar ring magnet 11 are shown in FIGS. 3B and 3C, which are the AA cross section and the BB cross section of FIG. In addition, different magnetic poles are alternately arranged in the circumferential direction such that, for example, the shaded portions in the figure are N poles and the non-shaded portions are S poles.
A pair of magnetic poles is composed of a set of S and N poles adjacent to each other in the circumferential direction of the first multipolar ring magnet 10 and the second multipolar ring magnet 11.

Moreover, the 1st multipolar ring magnet 10 and the 2nd multipolar ring magnet 11 can be comprised from a neodymium magnet, a ferrite magnet, a samarium cobalt magnet etc. according to a required magnetic flux density, for example.
The first rotation angle sensor 12 and the second rotation angle sensor 13 are provided at a fixed portion that does not rotate synchronously with the input shaft 22a that is the first rotation shaft and the output shaft 22b that is the second rotation shaft. The first rotation angle sensor 12 and the second rotation angle sensor 13 output a sine signal and a cosine signal according to the rotation angles of the first multipolar ring magnet 10 and the second multipolar ring magnet 11, respectively.

  Specifically, as shown in FIG. 2 and FIG. 3B, the first rotation angle sensor 12 is shifted in phase by an electrical angle of 90 ° with respect to the magnetic pole pitch (a state having a phase difference of 90 °). A) a first sine magnetic sensor 14 and a first cosine magnetic sensor 15 arranged. Further, as shown in FIG. 2 and FIG. 3C, the second rotation angle sensor 13 is shifted in phase by 90 ° in electrical angle with respect to the magnetic pole pitch (in a state having a phase difference of 90 °). A second sine magnetic sensor 16 and a second cosine magnetic sensor 17 are provided.

The first sine magnetic sensor 14 outputs a first sine signal according to the rotation angle of the first multipole ring magnet 10, and the first cosine magnetic sensor 15 corresponds to the rotation angle of the first multipole ring magnet 10. A first cosine signal is output.
The second sine magnetic sensor 16 outputs a second sine signal according to the rotation angle of the second multipole ring magnet 11, and the second cosine magnetic sensor 17 sets the rotation angle of the second multipole ring magnet 11. In response, a second cosine signal is output.

The output first sine signal, first cosine signal, second sine signal, and second cosine signal are input to the relative angle calculation unit 18.
In the first embodiment, the first sine magnetic sensor 14 and the first cosine magnetic sensor 15 are attached to the first multipole ring magnet 10 so that their detection units face the magnetic pole surface of the first multipole ring magnet 10. On the other hand, they are arranged opposite to each other in the radial direction. Further, the second sine magnetic sensor 16 and the second cosine magnetic sensor 17 are arranged in a radial direction with respect to the second multipole ring magnet 11 such that their detection portions face the magnetic pole surface of the second multipole ring magnet 11. It is arranged to face.

Further, for example, a Hall element, a Hall IC, a magnetoresistance effect (MR) sensor, or the like can be used for the magnetic sensors 14, 15, 16, and 17.
The relative angle calculation unit 18 is configured to determine a relative angle between the first multipolar ring magnet 10 and the second multipolar ring magnet 11 based on the input first sine signal, first cosine signal, second sine signal, and second cosine signal. (That is, the relative angle between the input shaft 22a and the output shaft 22b) Δθ is calculated. The relative angle calculation unit 18 outputs the calculated relative angle Δθ to the torque calculation unit 19.

The torque calculator 19 calculates the steering torque Ts based on the relative angle Δθ input from the relative angle calculator 18. If the relative angle Δθ between the two axes connected by the torsion bar is obtained, the torque can be calculated by a well-known calculation method using the cross-sectional secondary pole moment, transverse elastic modulus, length, diameter, etc. of the torsion bar. .
Next, a detailed configuration of the relative angle calculation unit 18 will be described.

As illustrated in FIG. 6, the relative angle calculation unit 18 includes a sin Δθ calculation unit 181, a cos Δθ calculation unit 182, and a Δθ calculation unit 183.
In the first embodiment, the rotation angle (electrical angle) of the first multipolar ring magnet 10 _is θ _is, and the rotation angle (electrical angle) of the second multipolar ring magnet 11 is θ _os . Further, when the steering wheel 21 is steered and the input shaft 22a rotates, θ _os is fixed at a predetermined angle, and θ _is is changed, so that “sin θ _is = sin (θ _os + Δθ)”, “cos θ _{It is} expressed as “ _is = cos (θ _os + Δθ)”.

That is, in the first embodiment, as shown in FIG. 4, the first sign signal from the first sign magnetic sensor 14 representative of the sin (θ _os + Δθ) is outputted, cos (θ _os + Δθ from the first cosine magnetic sensor 15 ) Is output. The second sine magnetic sensor 16 outputs a second sine signal representing sin θ _os , and the second cosine magnetic sensor 17 outputs a second cosine signal representing cos θ _os .

Hereinafter, the first sine signal, the first cosine signal, the second sine signal, and the second cosine signal are expressed as “sin (θ _os + Δθ)”, “cos (θ _os + Δθ)”, “sin θ _os ”, “cos θ _os ”. May be described.
The sin Δθ calculation unit 181 calculates sin Δθ according to the following equations (1) and (2).
TMs = {sin θ _os + cos (θ _os + Δθ)} ² + {cos θ _os −sin (θ os + Δθ)} ² (1)
sin Δθ = −TMs / 2 + 1 (2)
The above expression (2) is an expression obtained by transforming the above expression (1) by using an addition theorem of trigonometric functions.

Specifically, the sin Δθ calculation unit 181 adds the sin θ _os input from the second sine magnetic sensor 16 and the cos (θ _os + Δθ) input from the first cosine magnetic sensor 15 according to the above equation (1). The square value of is calculated. Further, a square value of a subtraction value obtained by subtracting sin (θ _os + Δθ) input from the first sine magnetic sensor 14 from cos θ _os input from the second cosine magnetic sensor 17 is calculated. Then, TMs is calculated by adding the calculated square values.

Subsequently, the sin Δθ computing unit 181 calculates sin Δθ by subtracting 1 from the calculated TMs divided by 2 according to the above equation (2). The sin Δθ calculation unit 181 outputs the calculated sin Δθ to the Δθ calculation unit 183.
The cos Δθ calculator 182 calculates cos Δθ according to the following equations (3) and (4).
TMc = {sin θ _os + sin (θ _os + Δθ)} ² + {cos θ _os + cos (θ _os + Δθ)} ² (3)
cosΔθ = TMc / 2-1 (4)
The above expression (4) is an expression obtained by transforming the above expression (3) using an addition theorem of trigonometric functions.

Specifically, Cosderutashita calculation unit 182, according to the above equation (3), the sum of the sin input from the second sign is inputted from the magnetic sensor 16 sin [theta _os the first sign magnetic sensor 14 (θ _os + Δθ) The square value of is calculated. Further calculates a square value of the sum of and the cos [theta] _os input from the second cosine magnetic sensor 17 is input from the first cosine magnetic sensor _{15 cos (θ os + Δθ)} . Then, TMc is calculated by adding the calculated square values.

Subsequently, the cos Δθ calculation unit 182 calculates cos Δθ by subtracting 1 from the calculated TMc divided by 2 according to the above equation (4). The cos Δθ calculator 182 outputs the calculated cos Δθ to the Δθ calculator 183.
For example, when the steering wheel 21 is steered and the input shaft 22a rotates from a state where the steering wheel 21 is in the neutral position, θ _os is fixed at “0 °” and θ _is changes.

In the state of fixing the theta _os at "0 °""sin [theta _os = 0" and "cos [theta] _os = 1", sin [theta _IS, as shown in FIG. 5 (a), the steering wheel 21 is Δθ at the neutral position It is “0” when “0 °”, “1” when Δθ is “90 °”, and “−1” when “−90 °”. On the other hand, as shown in FIG. 5B, cos θ _is is “1” when Δθ is “0 °” at the neutral position, and “0” when Δθ is “90 °” and “−90 °”. Become.

In this case, sin Δθ calculated according to the above equations (1) and (2) is “0” when Δθ is “0 °”, for example, as shown in FIG. "1" when "", and "-1" when "-90 °".
Further, cos Δθ calculated according to the above equations (3) and (4) is “1” when Δθ is “0 °”, for example, as shown in FIG. 7B, and Δθ is “90 °”. The value on the cosine curve becomes “0” at “−90 °”.

The Δθ calculator 183 calculates the relative angle Δθ according to the following equation (5).
Δθ = arctan (sin Δθ / cos Δθ) (5)
Specifically, the Δθ calculation unit 183 has an arc tangent of a value obtained by dividing sin Δθ by cos Δθ from the sin Δθ input from the sin Δθ calculation unit 181 and the cos Δθ input from the cos Δθ calculation unit 183 according to the above equation (5). Is calculated to calculate the relative angle Δθ. The relative angle calculation unit 18 outputs the calculated relative angle Δθ to the torque calculation unit 19.
The calculated relative angle (twist angle) Δθ is an angle having a 1: 1 relationship with the input twist angle, as shown in FIG. That is, by calculating the relative angle Δθ according to the above formulas (1) to (5), the torsion angle (relative angle) independent of the steering angle of the steering wheel 21 can be calculated.

(Operation)
Next, the operation of the first embodiment will be described.
Now, when the steering wheel 21 is steered by the driver of the vehicle 3 and this steering force is transmitted to the steering shaft 22, the input shaft 22a first rotates in a direction corresponding to the steering direction. With this rotation, the end of the torsion bar 22c on the input shaft 22a side (hereinafter referred to as “input end”) rotates, and the first multipolar ring magnet provided at the input end of the torsion bar 22c. 10 rotates.

The magnetic flux corresponding to the rotational displacement caused by this rotation is detected as sin (θ _os + Δθ) and cos (θ _os + Δθ) by the first sine magnetic sensor 14 and the first cosine magnetic sensor 15. These detection signals are input to the relative angle calculation unit 18.
On the other hand, the steering force that has passed through the input end is transmitted to the end on the output shaft 22b side (hereinafter referred to as “output end”) via torsion (elastic deformation) of the torsion bar 22c, and the output end rotates. . That is, the input end (input shaft 22a) and the output end (output shaft 22b) are relatively displaced in the rotation direction.

Thereby, the 2nd multipolar ring magnet 11 provided in the output end of the torsion bar 22c rotates. Flux corresponding to the rotational displacement by the rotation, in the second sign magnetic sensor 16 and the second cosine magnetic sensor 17 is detected as a sin [theta _os and cos [theta] _os. These detection signals are input to the relative angle calculation unit 18.
The relative angle calculation unit 18 calculates sin Δθ and cos Δθ from the inputted sin (θ _os + Δθ), cos (θ _os + Δθ), sin θ _os and cos θ _{os according} to the above equations (1) to (4). Then, the relative angle Δθ is calculated by obtaining the arc tangent of the value obtained by dividing sin Δθ by cos Δθ from the calculated sin Δθ and cos Δθ according to the above equation (5). The relative angle calculation unit 18 outputs the calculated relative angle Δθ to the torque calculation unit 19.

The torque calculator 19 calculates the steering torque Ts from the relative angle Δθ from the relative angle calculator 18. For example, when the torsion bar 22c is a solid cylindrical member, the steering torque Ts related to the torsion bar 22c is calculated from “Δθ = 32 · Ts · L / (π · D ⁴ · G)”. Note that L is the length of the torsion bar 22c, D is the diameter of the torsion bar 22c, and G is the transverse elastic modulus of the torsion bar 22c.

The torque calculation unit 19 outputs the calculated steering torque Ts to the EPS control unit 34.
The EPS control unit 34 calculates a current command value in the current command calculation circuit based on the steering torque Ts from the torque calculation unit 19, the vehicle speed V from the vehicle speed sensor 35, and the motor rotation angle θm from the electric motor 33. Furthermore, the EPS control unit 34 generates a three-phase alternating current according to the current command value calculated by the current command calculation circuit in the motor drive circuit, supplies the generated three-phase alternating current to the electric motor 33, and A steering assist force is generated in the motor 33.
Here, in the first embodiment, the rotation angle θ _{is of} the first multipole ring magnet 10 corresponds to the rotation angle θ _1, and the rotation angle θ _{os of} the second multipole ring magnet 11 corresponds to the rotation angle θ ₂ . .

(Effect of 1st Embodiment)
(1) The first relative angle detection apparatus 100 according to the first embodiment includes an input shaft 22a and an output shaft 22b that are arranged coaxially with different magnetic poles alternately arranged in the circumferential direction. The first multi-pole ring magnet 10 that rotates synchronously with 22a and the second multi-pole ring magnet 11 that has different magnetic poles alternately arranged in the circumferential direction and rotates synchronously with the output shaft 22b of the input shaft 22a and the output shaft 22b. When the first rotation angle sensor that first multipole ring magnet 10 outputs a first cosine signal representative of a first sign signal and cos [theta] _iS representative of the detected and sin [theta _iS flux corresponding to the rotation angle theta _iS during rotation 12, the second rotation angle in which the second multipole ring magnet 11 outputs a second cosine signal representative of a second sign signal and cos [theta] _os representative of the detected and sin [theta _os a magnetic flux corresponding to the rotation angle theta _os during rotation SE Calculating sin Δθ and cos Δθ corresponding to the relative angle Δθ between the input shaft 22a and the output shaft 22b based on the first signal 13, the first sine signal and the first cosine signal, and the second sine signal and the second cosine signal; A relative angle calculation unit that calculates a relative angle Δθ from Δθ = arctan (sin Δθ / cos Δθ).

  With this configuration, it is possible to calculate the relative angle Δθ by calculating both sin Δθ and cos Δθ and calculating the arc tangent of a value obtained by dividing the calculated sin Δθ by cos Δθ. As a result, the torque can be calculated even in the torsional angle region exceeding the linear portion of sin Δθ. As a result, it is possible to deal with a wider torque detection range. Further, since the entire information of sin Δθ can be utilized even in the same torque detection range, the resolution of the detected torque value can be increased. Further, since the relative angle Δθ can be calculated by a single calculation such as calculating arctan (sin Δθ / cos Δθ), a more accurate torque value can be calculated.

(2) In the first relative angle detection device 100 according to the first embodiment, the first multipolar ring magnet 10 and the second multipolar ring magnet 11 are attached to magnetic poles that are alternately different in the circumferential direction on the outer peripheral surface. It is made up of magnetism. The first rotation angle sensor 12 includes a magnetic flux detection unit (a first sine magnetic sensor 14 and a first cosine magnetic sensor 15) on the outer circumferential surface of the first multipolar ring magnet 10. It is arranged to face the formed magnetic pole surface. The second rotation angle sensor 13 includes a magnetic flux detection unit (a second sine magnetic sensor 16 and a second cosine magnetic sensor 17) on the outer circumferential surface of the second multipolar ring magnet 11. It is arranged to face the formed magnetic pole surface.
With this configuration, for example, when the arrangement space in the axial direction cannot be taken with respect to the ring magnet, the rotation angle sensor can be arranged in the radial direction.

(3) In the first relative angle detection device 100 according to the first embodiment, the first rotation angle sensor 12 has a phase difference of 90 ° in electrical angle with respect to the pitch of the magnetic poles of the first multipolar ring magnet 10. The first sine magnetic sensor 14 for outputting the first sine signal and the first cosine magnetic sensor 15 for outputting the first cosine signal, which are fixedly provided in a state having the first sine signal, are provided. In addition, the second rotation angle sensor 13 is provided with a second sine signal fixedly provided with a phase difference of 90 ° in electrical angle with respect to the pitch of the magnetic poles of the second multipolar ring magnet 11. A second sine magnetic sensor 16 for outputting and a second cosine magnetic sensor 17 for outputting a second cosine signal are provided.

With this configuration, the first sign magnetic sensor 14 and the first cosine magnetic sensor 15, it outputs a signal representative of sin [theta _IS and cos [theta] _IS corresponding to a rotation angle theta _IS first multipole ring magnet 10 in a simple Is possible. Further, the second sign magnetic sensor 16 and the second cosine magnetic sensor 17, it is possible to output a signal representative of sin [theta _os and cos [theta] _os in accordance with the rotation angle theta _os the second multipole ring magnet 11 in a simple .

(4) In the first relative angle detection device 100 according to the first embodiment, the first rotation angle sensor 12 and the second rotation angle sensor 13 have the first rotation angle sensor 12 when the relative angle Δθ is 0 °. The output and the output of the second rotation angle sensor 13 are provided to have the same phase.
With this configuration, sin Δθ and cos Δθ can be simply calculated according to the above equations (1) to (4) using the signals output from the first rotation angle sensor 12 and the second rotation angle sensor 13 as they are. It becomes possible.

(5) In the first relative angle detection device 100 according to the first embodiment, sin θ _is and cos θ _is are set to sin (θ _os + Δθ) and cos (θ _os + Δθ). Then, the relative angle calculation unit 18 calculates sin Δθ based on the following equations (6) to (7), and calculates cos Δθ based on the following equations (8) to (9).
TMs = {sin θ _os + cos (θ _os + Δθ)} ² + {cos θ _os −sin (θ _os + Δθ)} ² (6)
sin Δθ = −TMs / 2 + 1 (7)
TMc = {sin θ _os + sin (θ _os + Δθ)} ² + {cos θ _os + cos (θ _os + Δθ)} ² (8)
cosΔθ = TMc / 2-1 (9)
With this configuration, it is possible to calculate sin Δθ and cos Δθ by simple calculation using the signals output from the first rotation angle sensor 12 and the second rotation angle sensor 13 as they are.

(6) The first torque sensor 1 according to the first embodiment includes a relative angle between the input shaft 22a and the output shaft 22b connected by the torsion bar 22c by the first relative angle detection device 100 according to the first embodiment. A torque calculator 19 is provided that detects Δθ and calculates torque (steering torque Ts) generated in the input shaft 22a and the output shaft 22b from the relative angle Δθ.
If it is this structure, the effect | action and effect equivalent to the 1st relative angle detection apparatus 100 of any one of said (1)-(5) can be acquired.

(7) The electric power steering apparatus 2 according to the first embodiment includes the first torque sensor 1 according to the first embodiment.
With this configuration, it is possible to drive the electric motor with high-accuracy steering torque Ts corresponding to a wide torque detection range to generate appropriate steering assist torque. As a result, it is possible to perform good steering assist such as steering feeling.

(8) The vehicle 3 according to the first embodiment includes the electric power steering device 2 according to the first embodiment.
With this configuration, operations and effects equivalent to those of the electric power steering device 2 described in (7) above can be obtained.

(Second Embodiment)
(Constitution)
The second embodiment of the present invention has the same configuration as that of the first embodiment except that a second sensor unit 401 having a partially different configuration is provided instead of the first sensor unit 101 of the first embodiment. Become.
Hereinafter, the same components as those in the first embodiment are denoted by the same reference numerals, description thereof will be omitted as appropriate, and different portions will be described in detail.

The second torque sensor 4 according to the second embodiment includes a second relative angle detection device 400, and the second relative angle detection device 400 includes a second sensor unit 401 and a relative angle calculation unit 18. Prepare.
As shown in FIG. 9, the second sensor unit 401 includes a third multipole ring magnet 40 and a fourth multipole ring magnet 40 in place of the first multipole ring magnet 10 and the second multipole ring magnet 11 of the first embodiment. A multipolar ring magnet 41 is provided.

Unlike the first multipolar ring magnet 10 and the second multipolar ring magnet 11 of the first embodiment, the third multipolar ring magnet 40 and the fourth multipolar ring magnet 41 have the axial end faces of the ring magnet in the circumferential direction. In this configuration, different magnetic poles are alternately magnetized.
The mounting positions of the third multipolar ring magnet 40 and the fourth multipolar ring magnet 41 are the same as those of the first multipolar ring magnet 10 and the second multipolar ring magnet 11 of the first embodiment. Moreover, the 3rd multipolar ring magnet 40 and the 4th multipolar ring magnet 41 are comprised from the multipolar ring magnet of the same structure.

As shown in FIG. 9, the third multipolar ring magnet 40 and the fourth multipolar ring magnet 41 are arranged such that, for example, the shaded portion is N pole and the non-shaded portion is S pole. Magnetic poles different in direction are alternately arranged.
A pair of magnetic poles is composed of a set of S and N poles adjacent to each other in the circumferential direction of the third multipole ring magnet 40 and the fourth multipole ring magnet 41. Moreover, the 3rd multipolar ring magnet 40 and the 4th multipolar ring magnet 41 can be comprised from a neodymium magnet, a ferrite magnet, a samarium cobalt magnet etc. according to a required magnetic flux density, for example.

The second sensor unit 401 according to the second embodiment includes the first rotation angle sensor 12 and the second rotation angle sensor 13 that are the same as the first sensor unit 101 of the first embodiment. Is different from the first embodiment.
Specifically, as shown in FIG. 9, the first sine magnetic sensor 14 and the first cosine magnetic sensor 15 of the first rotation angle sensor 12 are arranged to face the magnetic pole surface of the third multipolar ring magnet 40. The three multipolar ring magnets 40 are arranged to face each other in the axial direction. In addition, the second sine magnetic sensor 16 and the second cosine magnetic sensor 17 of the second rotation angle sensor 13 are opposed to the fourth multipole ring magnet 41 so as to face the magnetic pole surface of the fourth multipole ring magnet 41. They are arranged facing each other in the axial direction.

Further, as shown in FIG. 9, the first sine magnetic sensor 14 and the first cosine magnetic sensor 15 of the second embodiment are shifted in phase by 90 ° in electrical angle with respect to the magnetic pole pitch (about 90 °). In a state having a phase difference). Further, as shown in FIG. 9, the second sine magnetic sensor 16 and the second cosine magnetic sensor 17 of the second embodiment are phase-shifted by 90 ° in electrical angle with respect to the magnetic pole pitch (about 90 °). In a state having a phase difference).
In addition, the 1st rotation angle sensor 12 and the 2nd rotation angle sensor 13 of 2nd Embodiment are provided in the fixed site | part which does not rotate synchronously with the input shaft 22a and the output shaft 22b.
Here, in the second embodiment, the rotation angle θ _{is of} the third multipole ring magnet 40 corresponds to the rotation angle θ _1, and the rotation angle θ _{os of} the fourth multipole ring magnet 41 corresponds to the rotation angle θ ₂ . .

(Effect of 2nd Embodiment)
In addition to the effects of the first embodiment, the second embodiment has the following effects.
(1) The second relative angle detection device 400 according to the second embodiment includes a third multi-pole ring magnet 40 and a first multi-pole ring magnet 40 which are formed by magnetizing a portion of one end face in the axial direction to different magnetic poles alternately in the circumferential direction. A 4-multipolar ring magnet 41 is provided. The first rotation angle sensor 12 has a magnetic flux detection unit (the first sine magnetic sensor 14 and the first cosine magnetic sensor 15) of the first rotation angle sensor 12 in one of the axial directions of the third multipole ring magnet 40. It is arranged to face the magnetic pole surface formed on the end face. Further, the second rotation angle sensor 13 has a magnetic flux detection unit (the second sine magnetic sensor 16 and the second cosine magnetic sensor 17) of the second rotation angle sensor 13 in the axial direction of the fourth multipolar ring magnet 41. It is arranged to face the magnetic pole surface formed on one end face.
With this configuration, for example, when the arrangement space in the radial direction cannot be taken with respect to the ring magnet, the rotation angle sensor can be arranged in an axially opposed manner.

(Third embodiment)
(Constitution)
The third embodiment of the present invention is the same as the first embodiment except that a third sensor unit 501 that uses a resolver to detect a relative angle is provided in place of the first sensor unit 101 of the first embodiment. It becomes the same composition.

Hereinafter, the same components as those in the first embodiment are denoted by the same reference numerals, description thereof will be omitted as appropriate, and different portions will be described in detail.
The third torque sensor 5 according to the third embodiment includes a third relative angle detection device 500, and the third relative angle detection device 500 includes a third sensor unit 501 and a relative angle calculation unit 18. Prepare.

As shown in FIGS. 10 and 11A, the third sensor unit 501 includes a first resolver 50, a second resolver 51, and an excitation signal supply unit 56.
In the example shown in FIG. 11B, the first resolver 50 is provided at the first rotor 52 having twelve teeth on the outer circumference and the fixed portion where neither the input shaft 22a nor the output shaft 22b rotates synchronously. And a first stator 53 having 16 armature windings (magnetic poles) formed by winding a coil around each of 16 poles equally distributed on the inner periphery.

In the example shown in FIG. 11C, the second resolver 51 is provided at the second rotor 54 having twelve teeth on the outer periphery and the fixed portion where the input shaft 22a and the output shaft 22b do not rotate synchronously. And a second stator 55 having 16 armature windings (magnetic poles) formed by winding a coil around each of 16 poles equally distributed on the inner circumference in the circumferential direction.
In the first resolver 50 and the second resolver 51, the number of teeth is not limited to 12, but may be 11 or less or 13 or more. The number of armature windings is not limited to 16, and may be 15 or less or 17 or more.

The first rotor 52 is attached to the input shaft 22a so as to be able to rotate synchronously with the input shaft 22a, and the second rotor 54 is attached to the output shaft 22b so as to be able to rotate synchronously with the output shaft 22b.
The first rotor 52 and the first stator 53 are arranged such that the first stator 53 is concentrically arranged outside the first rotor 52, and each tooth of the first rotor 52 and each armature winding of the first stator 53 have a diameter. They are arranged so as to face each other with a predetermined air gap in the direction.

The second rotor 54 and the second stator 55 are arranged such that the second stator 55 is disposed concentrically outside the second rotor 54, and each tooth of the second rotor 54 and each armature winding of the second stator 55 have a diameter. They are arranged so as to face each other with a predetermined air gap in the direction.
In the third embodiment, the first rotor 52 is attached to the end of the input shaft 22a on the output shaft 22b side (ideally, the connection position of the torsion bar 22c) so as to be able to rotate synchronously with the input shaft 22a. Further, the second rotor 54 is attached to the end of the output shaft 22b on the input shaft 22a side (ideally, the connecting position of the torsion bar 22c) so as to be able to rotate synchronously with the output shaft 22b.

The excitation signal supply unit 56 supplies a sinusoidal excitation signal to the coils of the armature windings of the first stator 53 and the second stator 55.
In the third embodiment, the first resolver 50 and the second resolver 51 are four-phase resolvers. That is, the poles of the first stator 53 and the second stator 55 are provided with a ¼ pitch shift from an integral multiple of the tooth pitch of the first rotor 52 and the second rotor 54.

  Thus, when the coil outputs of the 16 armature windings of the first stator 53 and the second stator 55 are divided into four 90 ° portions in the circumferential direction, four armature windings within the divided 90 ° circumferential direction are obtained. The output of the line coil is a sine wave (or cosine wave) signal that is 90 degrees out of phase between adjacent armature windings. In 3rd Embodiment, the coil which outputs the same signal among the coils of each armature winding is connected in series.

That is, when the rotation angle of the first rotor 52 and theta _IS, from coil output of the first stator 53, first cosine signal representative of a first sign signal and cos [theta] _IS represents a sin [theta _IS is obtained.
Further, when the rotation angle of the second rotor 54 and theta _os, from the output of the coils of the second stator 55, a second cosine signal representative of a second sign signal and cos [theta] _os represents the sin [theta _os is obtained.

Similarly to the first embodiment, “sin θ _is = sin (θ _os + Δθ)” and “cos θ _is = cos (θ _os + Δθ)” are set. That is, the first sine signal representing sin (θ _os + Δθ) and the first cosine signal representing cos (θ _os + Δθ) are obtained from the coil of the first stator 53.
The first sine signal and the first cosine signal and the second sine signal and the second cosine signal output from each coil are sent to the relative angle calculation unit 18 via a resolver cable (not shown) as shown in FIG. Entered.

The relative angle calculation unit 18 of the third embodiment is based on sin (θ _os + Δθ), cos (θ _os + Δθ), sin θ _os and cos θ _os input from the first stator 53 and the second stator 55 via the resolver cable. Similarly to the first embodiment, sin Δθ and cos Δθ are calculated according to the above equations (1) to (4). Then, the relative angle Δθ is calculated from the calculated sin Δθ and cos Δθ according to the above equation (5). Then, the calculated relative angle Δθ is output to the torque calculator 19.
Here, in the third embodiment, the rotation angle θ _is of the first rotor 52 corresponds to the rotation angle θ ₁ , and the rotation angle θ _os of the second rotor 54 corresponds to the rotation angle θ ₂ .

(Effect of the third embodiment)
The third embodiment has the following effects in addition to the effects of the first embodiment and the second embodiment.
(1) The third relative angle detection device 500 according to the third embodiment has a plurality of teeth equally spaced on the outer periphery, and the input shaft 22a and the output shaft 22b are arranged on the same axis as the input shaft. A first rotor 52 that rotates synchronously with 22a, and a second rotor 54 that has a plurality of teeth on the outer periphery at equal intervals and rotates synchronously with the output shaft 22b of the input shaft 22a and the output shaft 22b. Further, the first rotor 52 is arranged outside the first rotor 52 concentrically with a plurality of poles on the inner circumference, and armature windings are formed by coils wound around the poles. An armature winding is formed by a stator 53 and a coil that is concentrically arranged on the outer side of the second rotor 54 and concentrically with the second rotor 54 and has a plurality of poles arranged at the inner circumference and wound around each pole. The second stator 55 is provided. Still further, the excitation signal supply unit 56 that supplies excitation signals to the coils of the first stator 53 and the second stator 55, and the first rotor 52 that is output from the coils of the first stator 53 when the excitation signals are supplied. a first cosine signal representative of a first sign signal and cos [theta] _iS represents a sin [theta _iS in accordance with the rotation angle theta _iS, rotation of the second rotor 54 which is output from the coil of the second stator 55 when the excitation signal is supplied based on a second cosine signal representative of a second sign signal and cos [theta] _os represents the sin [theta _os in accordance with the angle theta _os, calculates the corresponding sinΔθ and cosΔθ the relative angle [Delta] [theta] between the input shaft 22a and output shaft 22b, [Delta] [theta] = Arctan (sinΔθ / cosΔθ) and a relative angle calculation unit that calculates the relative angle Δθ.

  With this configuration, it is possible to calculate the relative angle Δθ by calculating both sin Δθ and cos Δθ and calculating the arc tangent of a value obtained by dividing the calculated sin Δθ by cos Δθ. As a result, the torque can be calculated even in the torsional angle region exceeding the linear portion of sin Δθ. As a result, it is possible to deal with a wider torque detection range. Further, since the entire information of sin Δθ can be utilized even in the same torque detection range, the resolution of the detected torque value can be increased. Further, since the relative angle Δθ can be calculated by a single calculation such as calculating arctan (sin Δθ / cos Δθ), a more accurate torque value can be calculated.

(2) In the third relative angle detection device 500 according to the third embodiment, when the first stator 53 and the second stator 55 have a relative angle Δθ of 0 °, the output of the coil of the first stator 53 and the second The output of the coil of the stator 55 is provided so as to have the same phase.
With this configuration, sin Δθ and cos Δθ can be simply calculated according to the above equations (1) to (4) using signals output from the coils (detection coils) of the first stator 53 and the second stator 55. Is possible.

(Fourth embodiment)
The fourth embodiment of the present invention is the same as the first embodiment except that, in place of the first sensor unit 101 of the first embodiment, a fourth sensor unit 601 that uses an optical encoder to detect the rotation angle is provided. It becomes the same structure as 1 embodiment.
Hereinafter, the same components as those in the first embodiment are denoted by the same reference numerals, description thereof will be omitted as appropriate, and different portions will be described in detail.

The fourth torque sensor 6 according to the fourth embodiment includes a fourth relative angle detection device 600, and the fourth relative angle detection device 600 includes a fourth sensor unit 601 and a relative angle calculation unit 18. Prepare.
As shown in FIG. 13A, the fourth sensor unit 601 detects the rotation angle of the first code wheel 60 and the first and second code wheels 60 and 61 having an annular shape and a thin plate shape. 3 rotation angle sensor 62 and 4th rotation angle sensor 63 which detects the rotation angle of the 2nd code wheel 61 are provided.

In the first code wheel 60, a plurality of slits 60 s formed of rectangular through holes in a plan view are formed in the vicinity of the outer peripheral portion of the plate surface at equal intervals along the circumferential direction.
In the second code wheel 61, a plurality of slits 61s each having a rectangular through hole in a plan view are formed in the vicinity of the outer peripheral portion of the plate surface at equal intervals along the circumferential direction.
Moreover, in 4th Embodiment, the 1st code wheel 60 is attached to the output-shaft 22b side edge part (ideally the connection position of the torsion bar 22c) of the input shaft 22a so that synchronous rotation with the input shaft 22a is possible. Further, the second code wheel 61 is attached to the end of the output shaft 22b on the input shaft 22a side (ideally, the connection position of the torsion bar 22c) so as to be able to rotate synchronously with the output shaft 22b.

The third rotation angle sensor 62 and the fourth rotation angle sensor 63 are provided at a fixed portion where neither the input shaft 22a nor the output shaft 22b rotates synchronously. The third rotation angle sensor 62 and the fourth rotation angle sensor 63 output a sine signal and a cosine signal according to the rotation angles of the first code wheel 60 and the second code wheel 61, respectively.
Specifically, the third rotation angle sensor 62 includes a first sine optical sensor 64 disposed with a phase shift of 90 ° in electrical angle with respect to the slit pitch (with a phase difference of 90 °) and A first cosine optical sensor 65 is provided. Further, the fourth rotation angle sensor 63 shifts the phase by an electrical angle of 90 ° with respect to the slit pitch (in a state having a phase difference of 90 °) and the second sine optical sensor 66 and the second sensor. A cosine optical sensor 67 is provided.

The first sine optical sensor 64 outputs a first sine signal according to the rotation angle of the first code wheel 60, and the first cosine optical sensor 65 outputs a first cosine signal according to the rotation angle of the first code wheel. Output.
The second sine optical sensor 66 outputs a second sine signal according to the rotation angle of the second code wheel 61, and the second cosine optical sensor 67 outputs the second sine signal according to the rotation angle of the second code wheel 61. Output cosine signal.

As shown in FIG. 13B, the first sine optical sensor 64 includes a detection frame 62a having a substantially U-shaped axial section, a light source 62b, and a light receiving unit 62c.
The light source 62b is in the recess provided in the upper frame portion of the two frame portions facing the upper and lower sides inside the detection frame 62a, and the light receiving portion 62c is in the recess provided in the lower frame portion, respectively. The light receiving unit 62c is disposed so as to face the light emitted from the light source 62b so that the light can be received.

  As shown in FIG. 13A, the first sine optical sensor 64 is configured so that the entire slit 60a (through hole) passes through the space between the light source 62b and the light receiving unit 62c inside the detection frame 62a. The area including the slit formation position at the outer peripheral end of the one code wheel 60 is arranged so as to be sandwiched between the two frame portions of the detection frame 62a. That is, as shown in FIG. 13B, the light emitted from the light source 62b passes through the slit 60a so as to be received by the light receiving unit 62c.

The first cosine optical sensor 65, the second cosine optical sensor 66, and the second cosine optical sensor 67 have a detection frame code of 65a, 66a, and 67a, a light source code of 65b, 66b, and 67b, and a light receiving unit. Only the reference numerals are replaced with 65c, 66c, and 67c, respectively, and the configuration is the same as that of the first sine optical sensor 64, and the description thereof is omitted.
In the fourth embodiment, similarly to the first embodiment, the rotation angle (electrical angle) of the first code wheel 60 _is θ _is, and the rotation angle (electrical angle) of the second code wheel 61 is θ _os . To do. Further, a relative angle between the first code wheel 60 and the second code wheel 61 (that is, a relative angle between the input shaft 22a and the output shaft 22b) is set to Δθ.

Also in the fourth embodiment, as in the first embodiment, θ _os is fixed at a predetermined angle (for example, 0 °), and θ _is is changed.
That is, in the fourth embodiment, a first sine signal representing sin (θ _os + Δθ) is output from the first sine optical sensor 64, and a first cosine signal representing cos (θ _os + Δθ) from the first cosine optical sensor 65. Is output. The second sine optical sensor 66 outputs a second sine signal representing sin θ _os , and the second cosine optical sensor 67 outputs a second cosine signal representing cos θ _os .

These output sin (θ _os + Δθ), cos (θ _os + Δθ), sinθ _os and cosθ _os are input to the relative angle calculator 18 as shown in FIG.
The relative angle calculation unit 18 of the fourth embodiment includes sin (θ _os + Δθ) input from the first sine optical sensor 64, the first cosine optical sensor 65, the second sine optical sensor 66, and the second cosine optical sensor 67, Similar to the first embodiment, sin Δθ and cos Δθ are calculated from cos (θ _os + Δθ), sin θ _os and cos θ _{os according} to the above equations (1) to (4). Then, the relative angle Δθ is calculated from the calculated sin Δθ and cos Δθ according to the above equation (5). Then, the calculated relative angle Δθ is output to the torque calculator 19.
Here, in the fourth embodiment, the rotation angle θ _is of the first code wheel 60 corresponds to the rotation angle θ ₁ , and the rotation angle θ _os of the second code wheel 61 corresponds to the rotation angle θ ₂ .

(Effect of 4th Embodiment)
The fourth embodiment has the following effects in addition to the effects of the first to third embodiments.
(1) A fourth relative angle detection device 600 according to the fourth embodiment includes an input shaft 22a and an output shaft that have a plurality of slits 60s formed at equal intervals in the circumferential direction and are arranged coaxially. 22b has a first code wheel 60 that rotates synchronously with the input shaft 22a, and a plurality of slits 61s formed at equal intervals in the circumferential direction, and synchronously rotates with the output shaft 22b of the input shaft 22a and the output shaft 22b. And a second code wheel 61. Furthermore, the light source (light sources 64b and 65b) and the transmitted light that the light emitted from the light source passes through the slit 60s of the first code wheel 60 are received, and sin θ _is corresponding to the rotation angle θ _is of the first code wheel _is represented. A third rotation angle sensor 62 having a light receiving part (light receiving parts 64c and 65c) that outputs a first sine signal and a first cosine signal representing cos θ _is , a light source (light sources 66b and 67b), and light emitted from the light source There receives the light transmitted through the slit 61s of the second code wheel 61, a second cosine signal representative of a second sign signal and cos [theta] _os represents the sin [theta _os in accordance with the rotation angle theta _os of the second code wheel 61 output And a fourth rotation angle sensor 63 having a light receiving portion (light receiving portions 66c and 67c). Furthermore, sin Δθ and cos Δθ corresponding to the relative angle Δθ between the input shaft 22a and the output shaft 22b are calculated based on the first sine signal and the first cosine signal and the second sine signal and the second cosine signal, and Δθ = Arctan (sin Δθ / cos Δθ) and a relative angle calculation unit 18 for calculating the relative angle Δθ.

  With this configuration, it is possible to calculate the relative angle Δθ by calculating both sin Δθ and cos Δθ and calculating the arc tangent of a value obtained by dividing the calculated sin Δθ by cos Δθ. As a result, the torque can be calculated even in the torsional angle region exceeding the linear portion of sin Δθ. As a result, it is possible to deal with a wider torque detection range. Further, since the entire information of sin Δθ can be utilized even in the same torque detection range, the resolution of the detected torque value can be increased. Further, since the relative angle Δθ can be calculated by a single calculation such as calculating arctan (sin Δθ / cos Δθ), a more accurate torque value can be calculated.

(2) In the fourth relative angle detection device 600 according to the fourth embodiment, the third rotation angle sensor 62 and the fourth rotation angle sensor 63 output the first rotation angle sensor when the relative angle Δθ is 0 °. And the output of the second rotation angle sensor is provided to have the same phase.
With this configuration, it is possible to easily calculate sin Δθ and cos Δθ using the signals output from the third rotation angle sensor 62 and the fourth rotation angle sensor 63 according to the above equations (1) to (4). It becomes.

(Fifth embodiment)
5th Embodiment of this invention replaces the 1st sensor part 101 of the said 1st Embodiment, and is equipped with the 5th sensor part 701 which uses an eddy current for the detection of a rotation angle, said 1st above-mentioned. It becomes the same structure as embodiment.
Hereinafter, the same components as those in the first embodiment are denoted by the same reference numerals, description thereof will be omitted as appropriate, and different portions will be described in detail.

As shown in FIG. 15A, the fifth torque sensor 7 according to the fifth embodiment includes a fifth relative angle detection device 700, and the fifth relative angle detection device 700 includes a fifth sensor unit. 701 and a relative angle calculation unit 18.
The fifth sensor unit 701 includes a first target 70 and a second target 71, a fifth rotation angle sensor 72 that detects the rotation angle of the first target 70, and a sixth rotation that detects the rotation angle of the second target 71. An angle sensor 73.

The first target 70 is a sine wave shape along the circumferential direction of the first annular conductor 70a composed of an annular and thin plate-shaped conductor and the outer diameter side end of the first annular conductor 70a in plan view from the axial direction. And a first sine wave-like portion 70b formed in a shape that changes to the above. That is, the first sinusoidal portion 70b has a shape in which the radial width changes in a sinusoidal shape.
The second target 71 has a sine wave shape along the circumferential direction of the second annular conductor 71a composed of an annular and thin plate-shaped conductor and the outer diameter side end of the second annular conductor 71a in plan view from the axial direction. And a second sinusoidal portion 71b formed in a shape that changes to the above. That is, the second sinusoidal portion 71b has a shape in which the radial width changes in a sinusoidal shape.

The 1st target 70 and the 2nd target 71 can be comprised from conductors, such as metals, such as aluminum, steel, copper, or a plastic material containing a metal, for example.
Moreover, in 5th Embodiment, the 1st target 70 is attached to the output-shaft 22b side edge part (ideally the connection position of the torsion bar 22c) of the input shaft 22a so that synchronous rotation with the input shaft 22a is possible. Further, the second target 71 is attached to the end of the output shaft 22b on the input shaft 22a side (ideally, the connection position of the torsion bar 22c) so as to be able to rotate synchronously with the output shaft 22b.

The fifth rotation angle sensor 72 and the sixth rotation angle sensor 73 are provided at a fixed portion where neither the input shaft 22a nor the output shaft 22b rotates synchronously. The fifth rotation angle sensor 72 and the sixth rotation angle sensor 73 output a sine signal and a cosine signal according to the rotation angles of the first target 70 and the second target 71, respectively.
Specifically, the fifth rotation angle sensor 72 includes a substrate 72s as shown in FIG. Furthermore, the planar coils L1, L2 mounted on the front side surface 72a of the substrate 72s at positions where the change in inductance becomes + Sin, + Cos, -Sin, -Cos with respect to the first sinusoidal portion 70b of the first target 70. , L3, L4.

Further, as shown in FIG. 15C, the fifth rotation angle sensor 72 includes an ASIC (specific application IC) 72c mounted on the back side surface 72b of the substrate 72s, and a peripheral circuit 72d.
In the fifth embodiment, the fifth rotation angle sensor 72 is arranged in the axial direction with respect to the first target 70 such that the planar coils L1 to L4 face the first sinusoidal portion 70b of the first target 70. They are placed facing each other. Further, the sixth rotation angle sensor 73 is disposed so as to face the second target 71 in the axial direction so that the planar coils L1 to L4 face the second sine wave portion 71b of the second target 71. Yes.

  The fifth rotation angle sensor 72 applies current to the planar coils L1 to L4 to excite these planar coils, and generates an eddy current in the first target 70 by the magnetic flux generated by this excitation. Then, the peripheral circuit 72d detects a voltage change (eddy current loss) when the inductance of the planar coils L1 to L4 decreases due to the generated eddy current. This voltage change is detected as a differential signal of + Sin, + Cos, -Sin, and -Cos by the peripheral circuit 72d. The fifth rotation angle sensor 72 converts a differential signal corresponding to the rotation angle of the first target 70 detected by the peripheral circuit 72d into a single-ended signal by the ASIC 72c. And the 1st sine signal and 1st cosine signal which are the signals after conversion are output.

On the other hand, the sixth rotation angle sensor 73 is the same as the fifth rotation angle sensor 72 in that the substrate code is 73s, the front side code is 73a, the back side code is 73b, the ASIC code is 73c, and the peripheral circuit. Is replaced with 73d, and the configuration is the same as that of the fifth rotation angle sensor 72, and the description thereof is omitted.
The sixth rotation angle sensor 73 converts the differential signal corresponding to the rotation angle of the second target 71 detected by the peripheral circuit 73d into a single-ended signal in the ASIC 73c. And the 2nd sine signal and 2nd cosine signal which are the signals after conversion are output.

In the fifth embodiment, similarly to the first embodiment, the rotation angle (electrical angle) of the first target 70 _is θ _is, and the rotation angle (electrical angle) of the second target 71 is θ _os . Further, a relative angle between the first target 70 and the second target 71 (that is, a relative angle between the input shaft 22a and the output shaft 22b) is set to Δθ.
Also in the fifth embodiment, similarly to the first embodiment, θ _os is fixed at a predetermined angle (for example, 0 °), and θ _is is changed.

That is, in the fifth embodiment, the fifth rotation angle sensor 72 outputs a first sine signal representing sin (θ _os + Δθ) and a first cosine signal representing cos (θ _os + Δθ). The second cosine signal representative of a second sign signal, and cos [theta] _os from sixth rotation angle sensor 73 representative of the sin [theta _os is output.
These output sin (θ _os + Δθ), cos (θ _os + Δθ), sinθ _os and cosθ _os are input to the relative angle calculator 18 as shown in FIG.

The relative angle calculating portion 18 of the fifth embodiment, the fifth rotation angle sensor 72 and a sixth rotation angle sensor 73 is input from the _{sin (θ os + Δθ),} cos (θ os + Δθ), the sin [theta _os and cos [theta] _os, Similar to the first embodiment, sin Δθ and cos Δθ are calculated according to the above equations (1) to (4). Then, the relative angle Δθ is calculated from the calculated sin Δθ and cos Δθ according to the above equation (5). Then, the calculated relative angle Δθ is output to the torque calculator 19.
Here, in the fifth embodiment, the rotation angle θ _is of the first target 70 corresponds to the rotation angle θ ₁ , and the rotation angle θ _os of the second target 71 corresponds to the rotation angle θ ₂ . Further, the planar coils L1, L2, L3, and L4 correspond to inductance elements.

(Effect of 5th Embodiment)
In addition to the effects of the first to fourth embodiments, the fifth embodiment has the following effects.
(1) The fifth relative angle detection device 700 according to the fifth embodiment has an annular first sine wave portion 70b whose radial width changes in a sine wave shape along the circumferential direction, and is coaxial. A first target 70 that rotates synchronously with the input shaft 22a among the input shaft 22a and the output shaft 22b that are arranged is provided. Furthermore, the second target 71 has an annular second sine wave portion 71b whose diametrical width changes in a sine wave shape along the circumferential direction, and rotates synchronously with the output shaft 22b of the input shaft 22a and the output shaft 22b. Is provided. Furthermore, it has a plurality of inductance elements (planar coils L1 to L4) arranged on the fixed side with a predetermined gap from the first sinusoidal portion 70b, and an eddy current corresponding to the rotation angle θ _is of the first target 70 loss detect and comprises a fifth rotational angle sensor 72 for outputting a first cosine signal representative of a first sign signal and cos [theta] _iS represents a sin [theta _iS. Furthermore, it has a plurality of inductance elements (planar coils L1 to L4) arranged on the fixed side with a predetermined gap from the second sinusoidal portion 71b, and an eddy current corresponding to the rotation angle θ _os of the second target 71 loss detect and comprising a sixth rotation angle sensor 73 for outputting a second cosine signal representative of a second sign signal and cos [theta] _os represents the sin [theta _os. Further, based on the first sine signal and the first cosine signal and the second sine signal and the second cosine signal, sin Δθ and cos Δθ corresponding to the relative angle Δθ between the input shaft 22a and the output shaft 22b are calculated, and Δθ = A relative angle calculation unit 18 for calculating a relative angle Δθ from arctan (sin Δθ / cos Δθ) is provided.

  With this configuration, it is possible to calculate the relative angle Δθ by calculating both sin Δθ and cos Δθ and calculating the arc tangent of a value obtained by dividing the calculated sin Δθ by cos Δθ. As a result, the torque can be calculated even in the torsional angle region exceeding the linear portion of sin Δθ. As a result, it is possible to deal with a wider torque detection range. Further, since the entire information of sin Δθ can be utilized even in the same torque detection range, the resolution of the detected torque value can be increased. Further, since the relative angle Δθ can be calculated by a single calculation such as calculating arctan (sin Δθ / cos Δθ), a more accurate torque value can be calculated.

(2) The first target 70 has a first sinusoidal shape formed by changing the first annular conductor 70a and the outer diameter side end of the first annular conductor 70a into a sinusoidal shape in plan view from the axial direction. Part 70b. Furthermore, the second target 71 has a second annular conductor 71a and a second sinusoidal portion formed by changing the outer diameter side end of the second annular conductor 71a into a sinusoidal shape in plan view from the axial direction. 71b. Further, the fifth rotation angle sensor 72 is arranged in the axial direction of the first target 70 so that a plurality of inductance elements (planar coils L1 to L4) included in the fifth rotation angle sensor 72 are opposed to the first sine wave portion 70b. It arrange | positions facing one end surface. Further, the sixth rotation angle sensor 73 is arranged in the axial direction of the second target 71 so that the plurality of inductance elements (planar coils L1 to L4) of the sixth rotation angle sensor 73 are opposed to the second sine wave portion 71b. It arrange | positions facing one end surface.
With this configuration, for example, when the arrangement space in the radial direction cannot be obtained with respect to the target, the rotation angle sensor can be arranged in the axially opposed manner.

(Sixth embodiment)
(Constitution)
The sixth embodiment of the present invention is the same as the first embodiment except that, instead of the first sensor unit 101 of the first embodiment, a sixth sensor unit 801 that uses an eddy current to detect the rotation angle is provided. It becomes the same structure as embodiment.

Hereinafter, the same components as those in the first embodiment are denoted by the same reference numerals, description thereof will be omitted as appropriate, and different portions will be described in detail.
The sixth torque sensor 8 according to the sixth embodiment includes a sixth relative angle detection device 800, and the sixth relative angle detection device 800 includes a sixth sensor unit 801 and a relative angle calculation unit 18. Prepare.

The sixth sensor unit 801 includes a third target 80 and a fourth target 81, a seventh rotation angle sensor 82 that detects the rotation angle of the third target 80, and an eighth rotation that detects the rotation angle of the fourth target 81. An angle sensor 83.
The third target 80 is formed in a circular shape along the circumferential direction on the outer peripheral portion of the first cylindrical body 80a and the first cylindrical body 80a, and two sine waves are vertically symmetrical with each other in plan view. And a third sine wave portion 80b having a shape. That is, the third sinusoidal portion 80b has a shape in which the axial width changes in a sinusoidal shape.

The fourth target 81 has a cylindrical second cylindrical body 81a and two sine wave shapes formed in an annular shape along the circumferential direction on the outer peripheral portion of the second cylindrical body 81a so that the two sine wave shapes are symmetrically aligned with each other in a plan view. And a fourth sine wave-shaped portion 81b having the shape. That is, the fourth sinusoidal portion 81b has a shape in which the axial width changes to a sinusoidal shape.
The 3rd sine wave-shaped part 80b and the 4th sine wave-shaped part 81b can be comprised from conductors, such as metals, such as aluminum, steel, copper, or a plastic material containing a metal, for example.

In the sixth embodiment, the third target 80 is attached to the end of the input shaft 22a on the output shaft 22b side (ideally, the connection position of the torsion bar 22c) so as to be able to rotate synchronously with the input shaft 22a. Furthermore, the fourth target 81 is attached to the end of the output shaft 22b on the input shaft 22a side (ideally, the connection position of the torsion bar 22c) so as to be able to rotate synchronously with the output shaft 22b.
The seventh rotation angle sensor 82 and the eighth rotation angle sensor 83 are provided at a fixed portion where neither the input shaft 22a nor the output shaft 22b rotates synchronously. The seventh rotation angle sensor 82 and the eighth rotation angle sensor 83 output a sine signal and a cosine signal according to the rotation angles of the third target 80 and the fourth target 81, respectively.

Specifically, as shown in FIG. 17A, the seventh rotation angle sensor 82 has a curved surface along the outer peripheral surface that faces the outer peripheral surface of the third target 80. And the 7th rotation angle sensor 82 is provided with the planar coils L1, L2, L3, L4 provided on the curved surface 82a, as shown in FIG.17 (b).
That is, in the sixth embodiment, as shown in FIG. 17A, the seventh rotation angle sensor 82 has a planar coil L <b> 1 to L <b> 4 with a predetermined gap in the third sine wave portion 80 b of the third target 80. In order to face each other, the third target 80 is arranged to face the third target 80 in the radial direction.

Here, the planar coils L <b> 1 to L <b> 4 provided on the curved surface 82 a are arranged in a positional relationship such that the change in inductance is + Sin, + Cos, −Sin, −Cos with respect to the third sine wave-shaped portion 80 b of the third target 80. Has been.
Further, as shown in FIG. 17C, the seventh rotation angle sensor 82 includes a substrate 82s inside as viewed from the surface 82b opposite to the curved surface 82a. On the surface of the substrate 82s on the curved surface 82a side. And an ASIC 82c and a peripheral circuit 82d.

  The seventh rotation angle sensor 82 applies current to the planar coils L1 to L4 to excite these planar coils, and generates an eddy current in the third target 80 by the magnetic flux generated by this excitation. And the eddy current loss generate | occur | produces by this generated eddy current, and the inductance of the planar coils L1-L4 reduces. The voltage change at that time is detected by the peripheral circuit 82d. This voltage change is detected as a differential signal of + Sin, + Cos, -Sin, and -Cos.

That is, the seventh rotation angle sensor 82 detects the differential signal corresponding to the rotation angle of the third target 80 by the peripheral circuit 82d, and converts the detected differential signal into a single-ended signal by the ASIC 82c. And the 1st sine signal and 1st cosine signal which are the signals after conversion are output.
On the other hand, as shown in FIG. 17A, the eighth rotation angle sensor 83 has a curved surface along the outer peripheral surface that faces the outer peripheral surface of the fourth target 81.

Here, the eighth rotation angle sensor 83 has the curved surface code 83a, the surface opposite the curved surface 82a code 83b, the substrate code 83S, the ASIC code 83c, and the peripheral circuit code. Since the configuration is the same as that of the seventh rotation angle sensor 82 only by replacing with 83d, description thereof will be omitted.
And in 6th Embodiment, as shown to Fig.17 (a), as for the 8th rotation angle sensor 83, the planar coils L1-L4 leave a predetermined gap in the 4th sine wave-shaped part 81b of the 4th target 81. FIG. It arrange | positions so that it may oppose with respect to the 4th target 81 in the radial direction so that it may oppose.

Further, the eighth rotation angle sensor 83 detects a differential signal corresponding to the rotation angle of the fourth target 81 by the peripheral circuit 83d, and converts the detected differential signal into a single-ended signal by the ASIC 83c. And the 2nd sine signal and 2nd cosine signal which are the signals after conversion are output.
In the sixth embodiment, similarly to the first embodiment, the rotation angle (electrical angle) of the third target 80 _is θ _is and the rotation angle (electrical angle) of the fourth target 81 is θ _os . Further, a relative angle between the third target 80 and the fourth target 81 (that is, a relative angle between the input shaft 22a and the output shaft 22b) is set to Δθ.

Also in the sixth embodiment, similarly to the first embodiment, θ _os is fixed at a predetermined angle (for example, 0 °), and θ _is is changed.
That is, in the sixth embodiment, a first sine signal representing sin (θ _os + Δθ) and a first cosine signal representing cos (θ _os + Δθ) are output from the seventh rotation angle sensor 82. The second cosine signal representative of a second sign signal, and cos [theta] _os from the eighth rotation angle sensor 83 representative of the sin [theta _os is output.

These output sin (θ _os + Δθ), cos (θ _os + Δθ), sinθ _os and cosθ _os are input to the relative angle calculator 18 as shown in FIG.
The relative angle calculating portion 18 of the sixth embodiment, the seventh rotary angle sensor 82 and the eighth rotary angle sensor 83 is input from the _{sin (θ os + Δθ),} cos (θ os + Δθ), the sin [theta _os and cos [theta] _os, Similar to the first embodiment, sin Δθ and cos Δθ are calculated according to the above equations (1) to (4). Then, the relative angle Δθ is calculated from the calculated sin Δθ and cos Δθ according to the above equation (5). Then, the calculated relative angle Δθ is output to the torque calculator 19.
Here, in the sixth embodiment, the rotation angle θ _is of the third target 80 corresponds to the rotation angle θ ₁ , and the rotation angle θ _os of the fourth target 81 corresponds to the rotation angle θ ₂ . Further, the planar coils L1, L2, L3, and L4 correspond to inductance elements.

(1) The sixth relative angle detection device 800 according to the sixth embodiment has an annular third sine wave portion 80b whose axial width changes in a sine wave shape along the circumferential direction, and is coaxially arranged. A third target 80 that rotates synchronously with the input shaft 22a among the arranged input shaft 22a and output shaft 22b is provided. Further, the fourth target 81 has an annular fourth sine wave portion 81b whose axial width changes in a sine wave shape along the circumferential direction, and rotates synchronously with the output shaft 22b of the input shaft 22a and the output shaft 22b. Is provided. Furthermore, it has a plurality of inductance elements (planar coils L1 to L4) arranged on the fixed side with a predetermined gap from the third sinusoidal portion 80b, and an eddy current corresponding to the rotation angle θ _is of the third target 80 loss detect and comprising a seventh rotary angle sensor 82 for outputting a first cosine signal representative of a first sign signal and cos [theta] _iS represents a sin [theta _iS. Furthermore, it has a plurality of inductance elements (planar coils L1 to L4) arranged to face the fixed side with a predetermined gap from the fourth sinusoidal portion 81b, and an eddy current corresponding to the rotation angle θ _os of the fourth target 81 loss detect and comprises an eighth rotational angle sensor 83 which outputs a second cosine signal representative of a second sign signal and cos [theta] _os represents the sin [theta _os. Further, based on the first sine signal and the first cosine signal and the second sine signal and the second cosine signal, sin Δθ and cos Δθ corresponding to the relative angle Δθ between the input shaft 22a and the output shaft 22b are calculated, and Δθ = A relative angle calculation unit 18 for calculating a relative angle Δθ from arctan (sin Δθ / cos Δθ) is provided.

  With this configuration, it is possible to calculate the relative angle Δθ by calculating both sin Δθ and cos Δθ and calculating the arc tangent of a value obtained by dividing the calculated sin Δθ by cos Δθ. As a result, the torque can be calculated even in the torsional angle region exceeding the linear portion of sin Δθ. As a result, it is possible to deal with a wider torque detection range. Further, since the entire information of sin Δθ can be utilized even in the same torque detection range, the resolution of the detected torque value can be increased. Further, since the relative angle Δθ can be calculated by a single calculation such as calculating arctan (sin Δθ / cos Δθ), a more accurate torque value can be calculated.

(2) The third target 80 has a first cylindrical body 80a and a first target having a shape that is provided on the outer peripheral surface of the first cylindrical body 80a and that changes in a sinusoidal shape along the circumferential direction when the outer peripheral surface is viewed in plan. And three sine wave portions 80b. Furthermore, the fourth target 81 is provided on the outer peripheral surface of the second cylindrical body 81a and the second cylindrical body 81a. The fourth target 81 has a shape that changes in a sinusoidal shape along the circumferential direction when the outer peripheral surface is viewed in plan. And a sine wave portion 81b. The seventh rotation angle sensor 82 faces the outer peripheral surface of the third target 80 so that the plurality of inductance elements (planar coils L1 to L4) of the seventh rotation angle sensor 82 face the third sine wave portion 80b. Are arranged. Further, the eighth rotation angle sensor 83 is arranged on the outer peripheral surface of the fourth target 81 so that the plurality of inductance elements (planar coils L1 to L4) of the eighth rotation angle sensor 83 are opposed to the fourth sine wave portion 81b. Opposed to each other.
With this configuration, for example, when the arrangement space in the axial direction cannot be taken with respect to the target, the rotation angle sensor can be arranged in the radial direction.

(Modification)
(1) In said 4 embodiment, let the 1st code wheel 60 and the 2nd code wheel 61 be the structure by which the several slit was provided along the circumferential direction in the outer peripheral part vicinity of a board surface, and the light source light which passes a slit However, the present invention is not limited to this configuration. For example, an annular thin plate of the first code wheel 60 and the second code wheel 61 is formed of a non-reflective member, and the reflection is, for example, the same shape in the vicinity of the outer peripheral portion of the plate surface instead of the slit along the circumferential direction. It is good also as a structure which provides a reflective member and receives the reflected light of the light source light which injected into the reflective member in a light-receiving part.

(2) In the fourth embodiment, the first sine optical sensor 64 and the first cosine optical sensor 65 are phase-shifted by 90 ° in electrical angle with respect to the pitch of the slit 60s (the phase difference of 90 ° is changed). The second sine optical sensor 66 and the second cosine optical sensor 67 are phase-shifted by 90 ° in electrical angle with respect to the pitch of the slit 61s (to have a phase difference of 90 °). ) The configuration to be arranged. Not limited to this configuration, two slit rows with the same pitch are provided in the radial direction, and the other slit phase is shifted in phase in the radial direction by an electrical angle of 90 ° (having a phase difference of 90 °). It is good also as a structure arrange | positioned in a state. In the case of this configuration, for example, two optical sensors are arranged in the radial direction and fixedly arranged in the same phase, and the optical sensors are arranged so that the light source light transmitted through the slits can be received with respect to each slit row. However, since the sensor on the inner diameter side cannot be U-shaped due to the installation problem, the sensor configuration needs to be changed.

(3) In the first and second embodiments described above, the first sine magnetic sensor and the first cosine magnetic sensor output the first sine signal and the first cosine signal, and the second sine magnetic sensor and the first cosine magnetic sensor. Although the second cosine magnetic sensor is configured to output the second sine signal and the second cosine signal by the two magnetic sensors, the present invention is not limited to this configuration. For example, the first sine signal and the first cosine signal may be output from one first magnetic sensor, and the second sine signal and the second cosine signal may be output from one second magnetic sensor.

(4) In the fifth embodiment, the first and second sinusoidal portions 70b and 71b are formed on the outer diameter side ends of the first and second annular conductors 70a and 71a. Not exclusively. For example, an annular conductor pattern whose radial width changes in a sinusoidal shape along the circumferential direction is attached to one axial end surface of a cylindrical body (not limited to a conductor) that rotates synchronously with the input shaft 22a or the output shaft 22b. It is good also as another structure, such as setting it as the structure provided.

(5) Although the third and fourth sinusoidal portions 80b and 81b are provided on the outer peripheral surfaces of the first and second cylindrical bodies 80a and 81a in the sixth embodiment, the present invention is not limited to this configuration. For example, the third and fourth sinusoidal portions 80b and 81b may be provided on the inner peripheral surfaces of the first and second cylindrical bodies 80a and 81a. In this configuration, the seventh and eighth rotation angle sensors 82 and 83 are also provided inside the first and second cylindrical bodies 80a and 81a.
(6) In each of the above-described embodiments, the EPS control unit 34 has been described as an example of a configuration in which the EPS control unit 34 is fixedly supported on the housing of the electric motor 33. Other configurations such as disposing at different positions may be adopted.

(7) In each of the above embodiments, a three-phase brushless motor has been described as an example of the electric motor 33. However, the electric motor 33 is not limited to this configuration, and a brushless motor having four or more phases may be used. Other configurations such as a motor may be used.
(8) In each of the above-described embodiments, an example in which the present invention is applied to a column assist type electric power steering apparatus has been described. However, the present invention is not limited to this configuration. For example, the present invention is applied to a rack assist type or pinion assist type electric power steering apparatus. It is good also as composition to apply.

DESCRIPTION OF SYMBOLS 1 ... 1st torque sensor, 2 ... Electric power steering apparatus, 3 ... Vehicle, 4 ... 2nd torque sensor, 5 ... 3rd torque sensor, 6 ... 4th torque sensor, 10 ... 1st multipolar ring Magnet 11, second multipolar ring magnet 12, first rotation angle sensor 13, second rotation angle sensor 14, first sine magnetic sensor 15, first cosine magnetic sensor 16, second sine magnetic sensor , 17 ... 2nd cosine magnetic sensor, 18 ... Relative angle calculation unit, 19 ... Torque calculation unit, 21 ... Steering wheel, 22 ... Steering shaft, 22a ... Input shaft, 22b ... Output shaft, 22c ... Torsion bar, 40 ... First 3 multipolar ring magnets, 41... 4th multipolar ring magnet, 50... First resolver, 51... Second resolver, 52... First rotor, 53. 2 stators 56 ... excitation signal supply unit 60 ... first code wheel 61 ... second code wheel 62 ... third rotation angle sensor 63 ... fourth rotation angle sensor 64 ... first sine optical sensor 65 ... First cosine optical sensor, 66 ... second sine optical sensor, 67 ... second cosine optical sensor, 70 ... first target, 70b ... first sine wave portion, 71 ... second target, 71b ... second sine wave portion, 72 ... 5th rotation angle sensor, 73 ... 6th rotation angle sensor, L1-L4 ... Planar coil, 80 ... 3rd target, 81 ... 4th target, 82 ... 7th rotation angle sensor, 82b ... 3rd sinusoidal part 83 ... 8th rotation angle sensor, 83b ... 4th sine wave part, 100 ... 1st relative angle detection apparatus, 400 ... 2nd relative angle detection apparatus, 500 ... 3rd relative angle detection apparatus, 600 4th relative angle detection device, 700 ... 5th relative angle detection device, 800 ... 6th relative angle detection device, 101 ... 1st sensor part, 401 ... 2nd sensor part, 501 ... 3rd sensor , 601... Fourth sensor unit, 701... Fifth sensor unit, 801.

Claims (16)

A first multipolar ring magnet that rotates in synchronization with the first rotating shaft among the first rotating shaft and the second rotating shaft that are alternately arranged in the circumferential direction and are arranged coaxially.
Magnetic poles different from each other in the circumferential direction, and a second multipolar ring magnet that rotates synchronously with the second rotating shaft among the first rotating shaft and the second rotating shaft;
A first rotation angle sensor for outputting a first cosine signal representative of a first sign signal and cos [theta] ₁ represents the sin [theta ₁ by detecting the magnetic flux corresponding to the rotation angle theta ₁ of the first multipole ring magnet,
A second rotation angle sensor for outputting a second cosine signal representative of a second sign signal and cos [theta] ₂ represents a sin [theta ₂ by detecting the magnetic flux corresponding to the rotation angle theta ₂ of the second multipolar ring magnets,
Based on the first sine signal and the first cosine signal and the second sine signal and the second cosine signal, sin Δθ and cos Δθ corresponding to a relative angle Δθ between the first rotation axis and the second rotation axis. And a relative angle calculation unit that calculates the relative angle Δθ from Δθ = arctan (sin Δθ / cos Δθ). The first multi-pole ring magnet and the second multi-pole ring magnet are formed by magnetizing portions of the outer peripheral surface to different magnetic poles alternately in the circumferential direction,
In the first rotation angle sensor, a magnetic flux detection unit of the first rotation angle sensor is disposed to face a magnetic pole surface formed on an outer peripheral surface of the first multipolar ring magnet,
The said 2nd rotation angle sensor is arrange | positioned facing the magnetic pole surface formed in the outer peripheral surface of the said 2nd multipolar ring magnet in the magnetic flux detection part which the said 2nd rotation angle sensor has. Relative angle detector. The first multi-pole ring magnet and the second multi-pole ring magnet are formed by magnetizing a portion of one end face in the axial direction to different magnetic poles alternately in the circumferential direction,
The first rotation angle sensor is disposed so that a magnetic flux detection unit of the first rotation angle sensor is opposed to a magnetic pole surface formed on one end surface in the axial direction of the first multipolar ring magnet,
In the second rotation angle sensor, the magnetic flux detecting portion of the second rotation angle sensor is disposed to face a magnetic pole surface formed on one end surface in the axial direction of the second multipolar ring magnet. The relative angle detection device according to claim 1. The first rotation angle sensor outputs the first sine signal, which is fixedly provided with a phase difference of 90 ° in electrical angle with respect to the pitch of the magnetic poles of the first multipolar ring magnet. And a first cosine magnetic sensor for outputting the first cosine signal.
The second rotation angle sensor outputs the second sine signal, which is fixedly provided with a phase difference of 90 ° in electrical angle with respect to the magnetic pole pitch of the second multipolar ring magnet. 4. The relative angle detection device according to claim 1, further comprising: a second sine magnetic sensor that outputs the second cosine magnetic sensor that outputs the second cosine signal. 5. A first rotor that has a plurality of teeth on the outer periphery at equal intervals and is coaxially disposed, and rotates synchronously with the first rotation shaft among the first rotation shaft and the second rotation shaft;
A second rotor having a plurality of teeth on the outer periphery at equal intervals and rotating synchronously with the second rotation shaft among the first rotation shaft and the second rotation shaft;
A first stator that is concentrically arranged on the outer side of the first rotor, has a plurality of poles formed at equal intervals on the inner periphery, and has armature windings formed by coils wound around the poles; ,
A second stator that is arranged concentrically with the second rotor on the outside of the second rotor, has a plurality of poles formed at equal intervals on the inner periphery, and has armature windings formed by coils wound around the poles; ,
An excitation signal supply unit for supplying an excitation signal to the coil;
First cosine signal representative of a first sign signal and cos [theta] ₁ that represents the sin [theta ₁ in accordance with the rotation angle theta ₁ of the first rotor outputted from said coil of said first stator when the excitation signal is supplied and second cosine signal representative of a second sign signal and cos [theta] ₂ which represents the sin [theta ₂ in accordance with the rotation angle theta ₂ of the second rotor output from the coil of the second stator when the excitation signal is supplied Based on the above, a relative angle calculation unit that calculates sin Δθ and cos Δθ according to the relative angle Δθ between the first rotation axis and the second rotation axis, and calculates the relative angle Δθ from Δθ = arctan (sin Δθ / cos Δθ). And a relative angle detection device. A first code wheel that has a plurality of slits formed at equal intervals in the circumferential direction and that rotates synchronously with the first rotating shaft among the first rotating shaft and the second rotating shaft that are coaxially disposed;
A second code wheel having a plurality of slits formed at equal intervals in the circumferential direction and rotating synchronously with the second rotation shaft among the first rotation shaft and the second rotation shaft;
Light source, light emitted from the light source to receive light transmitted through the slit of the first code wheel, the first sign signal representative of sin [theta ₁ in accordance with the rotation angle theta ₁ of the first code wheel and cosθ _{A first} rotation angle sensor having a light receiving unit that outputs a first cosine signal representing 1;
Light source, light emitted from the light source to receive light transmitted through the slit of the second code wheel, the second sign signal representative of sin [theta ₂ in accordance with the rotation angle theta ₂ of the second code wheel and cosθ _{A second} rotation angle sensor having a light receiving unit that outputs a second cosine signal representing 2;
Based on the first sine signal and the first cosine signal and the second sine signal and the second cosine signal, sin Δθ and cos Δθ corresponding to a relative angle Δθ between the first rotation axis and the second rotation axis. And a relative angle calculation unit that calculates the relative angle Δθ from Δθ = arctan (sin Δθ / cos Δθ). The first rotating shaft and the second rotating shaft that have an annular first conductor portion whose width in the radial direction or the axial direction changes in a sine wave shape along the circumferential direction, and are arranged coaxially. A first target that rotates synchronously with the rotation axis;
It has an annular second conductor portion whose width in the radial direction or the axial direction changes in a sine wave shape along the circumferential direction, and rotates synchronously with the second rotation shaft among the first rotation shaft and the second rotation shaft A second target to
A plurality of inductance elements arranged on the fixed side with a predetermined gap from the first conductor portion, and detecting an eddy current loss corresponding to the rotation angle θ ₁ of the first target to express sin θ ₁ a first rotation angle sensor for outputting a first cosine signal representing one sine signal and cos [theta] _1,
A plurality of inductance elements arranged opposite to the fixed side with a predetermined gap from the second conductor portion, and detecting an eddy current loss according to the rotation angle θ ₂ of the second target to express sin θ ₂ A second rotation angle sensor for outputting a second sine signal and a second cosine signal representing cos θ ₂ ;
Based on the first sine signal and the first cosine signal and the second sine signal and the second cosine signal, sin Δθ and cos Δθ corresponding to a relative angle Δθ between the first rotation axis and the second rotation axis. And a relative angle calculation unit that calculates the relative angle Δθ from Δθ = arctan (sin Δθ / cos Δθ). The first conductor portion is formed in a shape that changes in a sinusoidal shape when viewed from the axial direction on the outer diameter side end portion of the first annular conductor,
The second conductor portion is formed in a shape that changes in a sinusoidal shape in plan view from the axial direction on the outer diameter side end portion of the second annular conductor,
The first rotation angle sensor is opposed to one end surface in the axial direction of the first target such that the plurality of inductance elements of the first rotation angle sensor are opposed to the sinusoidal portion of the first conductor portion. Arranged,
The second rotation angle sensor is opposed to one end surface in the axial direction of the second target such that the plurality of inductance elements of the second rotation angle sensor are opposed to the sinusoidal portion of the second conductor portion. The relative angle detection device according to claim 7, wherein the relative angle detection device is disposed. The first target includes a first cylindrical body, and the first conductor portion is provided on the outer peripheral surface of the first cylindrical body so as to change in a sinusoidal shape along the circumferential direction when the outer peripheral surface is viewed in plan view. And
The second target includes a second cylindrical body, and the second conductor portion is provided on the outer peripheral surface of the second cylindrical body so as to change in a sinusoidal shape along the circumferential direction when the outer peripheral surface is viewed in plan view. And
The first rotation angle sensor is disposed to face the outer peripheral surface of the first target so that the plurality of inductance elements of the first rotation angle sensor face the first conductor portion.
The second rotation angle sensor is disposed to face the outer peripheral surface of the second target such that the plurality of inductance elements of the second rotation angle sensor face the second conductor portion. The relative angle detection device described in 1.   The first rotation angle sensor and the second rotation angle sensor are provided so that the output of the first rotation angle sensor and the output of the second rotation angle sensor are in phase when the relative angle Δθ is 0 °. The relative angle detection device according to claim 1, wherein the relative angle detection device is provided.   The first stator and the second stator are provided such that when the relative angle Δθ is 0 °, the output of the coil of the first stator and the output of the coil of the second stator are in phase. Item 6. The relative angle detection device according to Item 5.   The first rotation angle sensor and the second rotation angle sensor are provided so that the output of the first rotation angle sensor and the output of the second rotation angle sensor are in phase when the relative angle Δθ is 0 °. The relative angle detection device according to claim 6, wherein the relative angle detection device is used. The sin θ ₁ and the cos θ ₁ are defined as sin (θ ₂ + Δθ) and cos (θ ₂ + Δθ),
The relative angle calculation unit calculates the sin Δθ based on the following equations (1) to (2), and calculates the cos Δθ based on the following equations (3) to (4). The relative angle detection device described in 1.
TMs = {sin θ ₂ + cos (θ ₂ + Δθ)} ² + {cos θ ₂ −sin (θ ₂ + Δθ)} ² (1)
sin Δθ = −TMs / 2 + 1 (2)
TMc = {sin θ ₂ + sin (θ ₂ + Δθ)} ² + {cos θ ₂ + cos (θ ₂ + Δθ)} ² (3)
cosΔθ = TMc / 2-1 (4)   The relative angle detection device according to claim 1 detects a relative angle Δθ between the input shaft and the output shaft connected by a torsion bar, and the input shaft and the output shaft are detected from the relative angle Δθ. A torque sensor including a torque calculation unit that calculates torque generated in the motor.   An electric power steering apparatus comprising the torque sensor according to claim 14.   A vehicle comprising the electric power steering device according to claim 15.

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