JP2001133211A - Rotation angle detector, torque sensor and steering device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rotation angle detector capable of obtaining the stable output of a magnetic sensor. SOLUTION: This detector is provided with parts 22a and 22b magnetically non-continuous in a rotary shaft direction intermittently provided in a parallel line shape along the peripheral surface of a rotary shaft 21, and a first magnetic sensor 25 to detect a magnetic field formed by the parts 22a and 22b. Based on the detection signal of the first magnetic sensor 25, the displacement angle from the first magnetic sensor 25 of the rotating direction of the rotary shaft 21 is detected.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotation angle detecting device for detecting a rotation angle, a torque sensor for detecting a torque applied to an input shaft by a torsion angle generated in a connection shaft connecting an input shaft and an output shaft, and a torque sensor for detecting the rotation angle. The present invention relates to a steering device that drives an electric motor based on a detection result of a torque sensor to generate a steering assist force.

[0002]

2. Description of the Related Art There is a steering apparatus for an automobile that drives an electric motor to assist the steering to reduce the burden on the driver. It comprises an input shaft connected to a steered wheel (steering wheel), an output shaft connected to a steered wheel by a pinion and a rack, and a connection shaft connecting the input shaft and the output shaft. In addition, a torque sensor detects a steering torque applied to an input shaft, and based on the steering torque detected by the torque sensor, controls driving of an electric motor for steering assistance linked to an output shaft. In addition, the steering angle midpoint of the steered wheels is obtained by the rotation angle detecting device, and the drive control of the electric motor according to the steered angle of the steered wheels is also performed.

FIG. 6 shows that the present applicant filed a patent application No.
It is a principle diagram which shows the example of a principal part structure of the rotation angle detection apparatus proposed in 88882. This rotation angle detection device
In this case, the steering wheel 20 is connected to the upper end and the pinion 23 is connected to the lower end.
A projection 22 (projection) made of a magnetic material is provided spirally along the peripheral surface of the intermediate portion of the steering shaft 21 (steering shaft) to which is connected.

[0004] Further, the rotation angle detecting device includes a projection 22 made of a magnetic material that moves in the axial direction of the steering shaft 21 when the steering shaft 21 rotates.
In order to detect the position, the MR sensor 24 (magnetoresistive element, magnetic sensor) is provided in parallel with the steering shaft 21 with an appropriate gap, and is fixed to a portion where the vehicle body does not move. The MR sensor 24 includes, for example, a voltage dividing circuit including two magnetic resistances, and is configured to output the divided voltage. Further, in order to increase the change in the magnetic field due to the projection 22 made of a magnetic material and increase the sensitivity, a bias magnet is provided on the side not facing the steering shaft 21 to enhance the magnetic field on the surface of the steering shaft 21.

In the rotation angle detecting device having such a configuration, the protrusion made of a magnetic material closest to the detection surface of the MR sensor 24 according to the rotation of the steering shaft 21 in the range of 0 ≦ θ <360 °. 22 moves in the axial direction of the steering shaft 21. Projection 22 made of magnetic material
As shown in FIG. 7A which is a developed view of the peripheral surface of the steering shaft 21, it is spirally provided along the peripheral surface of the steering shaft 21.

For this reason, the axial position of the steering shaft 21 of the protrusion 22 made of a magnetic material closest to the detection surface of the MR sensor 24 can correspond to the rotation angle of the steering shaft 21. Therefore, if the output voltage of the MR sensor 24 and the rotation angle (steering angle) of the steering shaft 21 are set to have a linear relationship, the rotation of the steering shaft 21 is determined based on the output voltage of the MR sensor 24. The angle can be detected.

[0007]

In the rotation angle detecting device described above, the starting end (for example, 0 mm) of the protrusion 22 made of a magnetic material is used.
°) and near the end (for example, 360 °) are affected by the magnetic field due to the nearby protrusions 22, and the output voltage of the MR sensor 24 becomes the position of the protrusions 22 as shown in FIG. There is a problem that the waveform is not reflected and shows a broken waveform. However, since the sensitivity of the MR sensor 24 (change in output voltage per unit rotation angle) increases in a portion where the waveform is broken, a stable output of the MR sensor 24 can be obtained.

The present invention has been made in view of the above-mentioned circumstances, and it is an object of the first to fourth inventions to provide a rotation angle detecting device capable of obtaining a stable output of a magnetic sensor. I do. A fifth aspect of the present invention aims to provide a torque sensor capable of obtaining a stable output of a magnetic sensor. In a sixth aspect, an object is to provide a rotation angle detecting device according to any one of the first to fourth aspects and a steering device using the torque sensor according to the fifth aspect.

[0009]

According to a first aspect of the present invention, there is provided a rotation angle detecting device which is provided intermittently in a parallel line along a peripheral surface of a rotation shaft, and includes a portion which is magnetically discontinuous in the rotation axis direction. A first magnetic sensor for detecting a magnetic field formed by the portion, and detecting a displacement angle of the rotation axis of the rotation shaft from the first magnetic sensor based on a detection signal of the first magnetic sensor. It is characterized by what it does.

In this rotation angle detecting device, a portion that is magnetically discontinuous in the rotation axis direction is provided intermittently in a parallel line along the peripheral surface of the rotation shaft. The first magnetic sensor detects a magnetic field formed by a magnetically discontinuous portion, and detects the first magnetic sensor.
Based on a detection signal of the magnetic sensor, a displacement angle of the rotation direction of the rotation shaft from the first magnetic sensor is detected. This allows
A stable magnetic sensor output can be obtained, and magnetically discontinuous portions are provided intermittently in parallel lines along the circumference of the rotating shaft, making it easy to detect the rotation angle. The device can be realized.

[0011] The rotation angle detecting device according to the second invention is characterized in that the magnetically discontinuous portion is a protrusion or a depression made of a magnetic material.

In this rotation angle detecting device, the magnetically discontinuous portion is a projection or a depression made of a magnetic material.
A stable output of the magnetic sensor can be obtained, and the projections are provided intermittently in a parallel line along the peripheral surface of the rotating shaft. Can be done.

[0013] A rotation angle detecting device according to a third aspect of the invention is characterized in that the magnetically discontinuous portions are provided alternately in parallel lines and at equal intervals in the rotation direction.

In this rotation angle detecting device, the magnetically discontinuous portions are provided alternately in parallel lines and at equal intervals in the rotation direction, so that a stable periodic output of the magnetic sensor can be obtained. Since the magnetically discontinuous portion is provided intermittently in a parallel line along the peripheral surface of the rotating shaft, a rotation angle detecting device that is easy to work can be realized. .

A rotation angle detecting device according to a fourth aspect of the present invention further comprises a second magnetic sensor for detecting a magnetic field formed by the portion at a position different from the first magnetic sensor by a predetermined angle in the rotation direction, The displacement angle is detected based on each detection signal of the second magnetic sensor and the first magnetic sensor.

In this rotation angle detecting device, the second magnetic sensor detects a magnetic field formed by a magnetically discontinuous portion at a position different from the first magnetic sensor by a predetermined angle in the rotation direction, and the second magnetic sensor And a displacement angle is detected based on each detection signal of the first magnetic sensor. Thus, the rotation angle of each detection signal during one cycle can be specified from the relationship between the detection signals of the first magnetic sensor and the second magnetic sensor. In addition, a stable periodic output of the magnetic sensor can be obtained, and magnetically discontinuous portions are provided intermittently in parallel lines along the peripheral surface of the rotating shaft, so that machining is easy. A certain rotation angle detecting device can be realized.

A torque sensor according to a fifth aspect of the present invention is a torque sensor for detecting a torque applied to an input shaft by a torsion angle generated in a connecting shaft connecting the input shaft and the output shaft, wherein the torque sensor is attached to each of the input shaft and the output shaft. A rotation angle detecting device according to any one of claims 1 to 4, and a means for detecting a difference between the displacement angles respectively detected by the rotation angle detecting device, wherein the difference between the displacement angles detected by the means is provided. Is set to be the torsion angle.

In this torque sensor, the torque applied to the input shaft is detected by the torsion angle generated on the connecting shaft connecting the input shaft and the output shaft. The rotation angle detecting device according to any one of claims 1 to 4 is attached to each of the input shaft and the output shaft, and the detecting means detects a difference between the displacement angles detected by the rotation angle detecting device. The difference between the displacement angles detected by the detecting means is defined as a torsion angle. Thereby, a stable output of the magnetic sensor can be obtained, and the magnetically discontinuous portion is provided intermittently in a parallel line along the peripheral surface of the rotating shaft, so that the work is easy. A torque sensor can be realized.

According to a sixth aspect of the present invention, there is provided a steering device comprising: an input shaft connected to a steered wheel; an electric motor for steering assistance driven and controlled based on a steering torque applied to the steered wheel; and an output shaft interlocked with the electric motor. And a torque sensor according to claim 5, wherein a steering torque applied to the input shaft is detected by a torsion angle generated in a connection shaft connecting the input shaft and the output shaft, and a rotation angle detection of the torque sensor is provided. It is characterized in that a steering angle of the steered wheels is detected by a device.

In this steering system, the input shaft is connected to the steered wheels, and the electric motor for assisting steering is driven and controlled based on the steering torque applied to the steered wheels. The output shaft is interlocked with an electric motor for steering assistance, and the torque sensor according to claim 5 detects a steering torque applied to the input shaft by a torsion angle generated in a connecting shaft connecting the input shaft and the output shaft. . A rotation angle detection device of the torque sensor detects a steering angle of a steered wheel. This makes it possible to realize a rotation angle detecting device according to any of the first to fourth inventions and a steering device using the torque sensor according to the fifth invention.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings showing an embodiment. Embodiment 1 FIG. FIG. 1 is a principle diagram showing a main configuration of a rotation angle detecting device according to a first embodiment of the present invention. This rotation angle detection device shows a case where the rotation angle detection device is used in a steering device. The rotation angle detection device has a periphery of an intermediate portion of a steering shaft 21 (steering shaft) having an upper end connected to a steering wheel 20 and a lower end connected to a pinion 23. Protrusions 22a and 22b made of a magnetic material are provided along the surface. Projections 22a, 2
As shown in the developed view of the peripheral surface of the steering shaft 21 in FIG. 2 (a), 2b are provided alternately in parallel lines and at equal intervals in the rotation direction, for example, two are provided.

Further, the rotation angle detecting device is configured such that when the steering shaft 21 rotates, the magnetic field formed in the vicinity of the peripheral surface by the protrusions 22a and 22b made of the magnetic material of the steering shaft 21 in the axial direction thereof. In order to detect the strongest point, the MR sensor 25 (a magnetoresistive element,
A first magnetic sensor) is provided in parallel with the steering shaft 21 with an appropriate gap, and is fixed to a portion where the vehicle body does not move.

The rotation angle detecting device detects the rotation angle of the steering shaft 21 from the MR sensor 25.
In order to detect the strongest point in the axial direction of the magnetic field formed near the peripheral surface by the protrusions 22a and 22b at the rotated position, the MR sensor 26 (second magnetic sensor) is appropriately connected to the steering shaft 21. It is provided in parallel with a large gap, and is fixed to a part where the vehicle body does not move. The output voltages of the MR sensors 25 and 26 are supplied to a signal processing unit 27. The signal processing unit 27 detects the rotation angle of the steering shaft 21 based on the supplied output voltages and outputs a voltage signal. .

The MR sensors 25 and 26 are, for example, as shown in FIG.
A voltage dividing circuit including two magnetic resistors R1 and R2 shown in (b) is provided to output the divided voltage. Magnetic resistance R
1 and R2, and the protrusion 22 shown in FIG.
The distance L between a and 22b is in a relationship of P> L. The length B of the magnetic resistances R1 and R2 and the protrusion 2 shown in FIG.
The lengths A of 2a and 22b are shown in FIGS. 3B and 3C described later.
Are determined so that the slopes of the output voltage waveforms of the MR sensors 25 and 26 shown in FIG.

The MR sensors 25 and 26 are provided with bias magnets on the side not facing the steering shaft 21 in order to increase the change in the magnetic field due to the protrusions 22a and 22b made of magnetic material and to increase the sensitivity. The magnetic field on the surface of the shaft 21 is strengthened. As shown in FIG. 2A, the protrusions 22a and 22b made of a magnetic material have their start ends (ends) and ends (start ends) at the same circumferential position, that is, do not overlap. As described above, it is desirable to provide such that there is no gap.

In the rotation angle detecting device having such a configuration, as the steering shaft 21 rotates in the range of 0 ≦ θ <360 °, the magnetic field formed by the projections 22a and 22b The strongest point in the axial direction is displaced. The MR sensors 25 and 26 detect the position of the strongest point at which the displacement occurs, and output voltages having waveforms as shown in FIGS. Each output voltage of the MR sensors 25 and 26 has a periodic waveform as shown in FIGS. 3B and 3C depending on the positional relationship with the protrusions 22a and 22b shown in FIG. In this case, since there are two projections 22a and 22b, respectively,
During rotation, each output voltage of the MR sensors 25 and 26 is
Two cycles are output.

As described above, the MR sensor 26 is an MR sensor.
The output voltage is different from the output voltage of the MR sensor 25 by a quarter period as shown in FIGS. are doing. Therefore, the output voltage of the MR sensor 25 is
From the relationship with the output voltage of the MR sensor 26, the rotation angle corresponding to each voltage value in one cycle can be determined. The signal processing unit 27 detects the rotation angle of the steering shaft 21 based on the output voltages of the MR sensors 25 and 26 based on the relationship, and outputs the voltage signal.

Embodiment 2 FIG. 4 is a principle diagram showing a main part configuration of an embodiment of the torque sensor according to the present invention.
This torque sensor shows a case where it is used for a steering device, and a steering wheel 30 is connected to an upper end portion.
Protrusions 32a and 32b made of a magnetic material are provided along a peripheral surface of an intermediate portion of an upper shaft 31 (input shaft) of a steering shaft (steering shaft) to which a torsion bar 37 is connected at a lower end. The projections 32a and 32b are provided alternately in parallel lines and at equal intervals in the rotation direction, for example, two at a time, similarly to the projections 22a and 22b shown in the developed view of FIG.

Further, when the upper shaft 31 rotates, the torque sensor has a protrusion 3 made of a magnetic material of the upper shaft 31.
2a, 32b of the magnetic field formed near the peripheral surface thereof,
In order to detect the strongest point in the axial direction, the MR sensor 39 is used.
(Magnetoresistance effect element, first magnetic sensor) is provided in parallel with the upper shaft 31 with an appropriate gap, and is fixed to a portion where the vehicle body does not move.

The torque sensor is an MR sensor 3
9 at a position rotated by 45 ° in the rotation direction of the upper shaft 31,
In order to detect the strongest point in the axial direction of the magnetic field formed near the peripheral surface by the protrusions 32a and 32b, the MR sensor 40 (second magnetic sensor) is parallel to the upper shaft 31 with an appropriate gap. And is fixed to a stationary part of the vehicle body.

The lower shaft 33 (output shaft) of the steering shaft has an upper end connected to a torsion bar 37 and a lower end connected to a pinion 38. Like the upper shaft 31, protrusions 34a and 34b made of a magnetic material are provided along the peripheral surface of the intermediate portion of the lower shaft 33. Projections 34a, 3
4b are projections 22a and 22b shown in the development of FIG.
In the same manner as described above, two parallel lines are provided alternately and at equal intervals in the rotation direction, for example, two are provided.

When the lower shaft 33 rotates, the torque sensor is provided with a projection 3 made of a magnetic material of the lower shaft 33.
4a, 34b of the magnetic field formed near the peripheral surface
In order to detect the strongest point in the axial direction, the MR sensor 41
A (magnetoresistive element, first magnetic sensor) is provided in parallel with the lower shaft 33 with an appropriate gap, and is fixed to a portion where the vehicle body does not move.

The torque sensor is an MR sensor 4
At a position rotated by 45 ° in the rotation direction of the lower shaft 33 from 1;
In order to detect the strongest point in the axial direction of the magnetic field formed near the peripheral surface by the protrusions 34a and 34b, the MR sensor 42 (second magnetic sensor) is parallel to the lower shaft 33 with an appropriate gap. And is fixed to a stationary part of the vehicle body. Each output voltage of the MR sensors 39, 40, 41, 42 is given to a signal processing unit 35, and the signal processing unit 35
Based on each applied output voltage, a steering torque applied to steering wheel 30 is detected, and a voltage signal indicating the detected torque is output.

The signal processing unit 35 includes the MR sensor 4
A rotation angle (steering angle) of the steering shaft is detected based on the output voltages 1 and 42, and a voltage signal indicating the detected rotation angle is output. Since the twist angle of the torsion bar 37 is at most several degrees, a voltage signal indicating the rotation angle (steering angle) of the steering shaft may be output based on the output voltages of the MR sensors 39 and 40.

In the torque sensor having such a configuration, the signal processing unit 35 uses the output voltages of the MR sensors 39, 40, 41, and 42 to control the upper shaft 31 and the lower shaft 33 according to the first embodiment. The rotation angle is detected similarly to the rotation angle detection device described above. Here, if the steering torque is applied to the steering wheel 30 and the torsion bar 37 has a twist angle, the rotation angles of the upper shaft 31 and the lower shaft 33 are different from each other, and the difference is the twist angle.

The signal processing unit 35 calculates the torsion angle
The steering torque applied to the steering wheel 30 can be obtained, and a voltage signal indicating the steering torque can be output. The signal processing unit 35 can output a voltage signal indicating the rotation angle of the lower shaft 33 as a voltage signal indicating the rotation angle (steering angle) of the steering shaft.

Embodiment 3 FIG. 5 is a longitudinal sectional view showing a configuration of a main part of an embodiment of the steering device according to the present invention. The steering device includes an upper shaft 2 to which a steering wheel 1 is attached at an upper end, and a first shaft at a lower end of the upper shaft 2.
The upper end of a cylindrical input shaft 5 and a connecting shaft (torsion bar) 6 inserted inside the cylindrical input shaft 5 are connected via a dowel pin 4. A cylindrical output shaft 8 is connected to a lower end of the connection shaft 6 via a second dowel pin 7, and the upper shaft 2, the input shaft 5 and the output shaft 8 are connected to the housing via bearings 9, 10 and 11. 12 are rotatably supported in each.

In the housing 12, the connecting shaft 6 is provided.
A torque sensor 13 that detects a steering torque based on a relative displacement amount of the input shaft 5 and the output shaft 8 that are connected to each other via a motor, and a steering assist electric motor 14 that is driven based on the detection result of the torque sensor 13 is rotated. A speed reduction mechanism 15 for decelerating and transmitting the output to the output shaft 8, wherein the operation of the steering mechanism according to the rotation of the steering wheel 1 is controlled by the electric motor 14.
, And is configured to reduce the labor burden on the driver for steering. The lower end of the output shaft 8 is connected to a rack and pinion type steering mechanism via a universal joint.

The torque sensor 13 is provided with protrusions 32a, 32b made of a magnetic material along the peripheral surface 13a of the input shaft 5.
Is provided. The projections 32a and 32b are provided alternately in parallel lines and at equal intervals in the rotation direction, for example, two at a time, similarly to the projections 22a and 22b shown in the developed view of FIG. Further, when the input shaft 5 rotates, the torque sensor is provided with protrusions 32a, 3 made of a magnetic material of the input shaft 5.
In order to detect the strongest point in the axial direction of the magnetic field formed near the peripheral surface by 2b, the MR sensor 39 (magnetoresistive element, first magnetic sensor) is separated from the input shaft 5 by an appropriate gap. It is provided in parallel and is fixed to a part where the body does not move.

The torque sensor is an MR sensor 3
In order to detect the strongest point in the axial direction of the magnetic field formed near the peripheral surface 13a by the projections 32a, 32b at a position rotated by 45 degrees from the input shaft 5 in the rotation direction of the input shaft 5, an MR sensor (not shown) A (second magnetic sensor) is provided in parallel with the input shaft 5 with an appropriate gap, and is fixed to a portion where the vehicle body does not move.

The output shaft 8 is, like the input shaft 5, the output shaft 8.
Along the circumferential surface 13b of the projection 34a,
34b is provided. As shown in FIG.
Similar to the projections 22a and 22b shown in the developed view of (a), for example, they are alternately arranged in parallel lines and at equal intervals in the rotation direction.
There are two addresses. When the output shaft 8 rotates, the torque sensor detects the strongest point in the axial direction of the magnetic field formed in the vicinity of the peripheral surface by the protrusions 34a and 34b made of the magnetic material of the output shaft 8. For the MR sensor 4
Reference numeral 1 (a magnetoresistive element, a first magnetic sensor) is provided in parallel with the output shaft 8 with an appropriate gap, and is fixed to a portion where the vehicle body does not move.

The torque sensor is an MR sensor 4
In order to detect the strongest point in the axial direction of the magnetic field formed near the peripheral surface 13b by the protrusions 34a and 34b at a position rotated by 45 degrees from 1 in the rotation direction of the output shaft 8, an MR sensor (not shown) A (second magnetic sensor) is provided in parallel with the output shaft 8 with an appropriate gap, and is fixed to a portion where the vehicle body does not move. The output voltages of the MR sensors 39 and 41 and the two MR sensors (not shown) are supplied to a control unit (not shown).
The steering torque applied to the steering wheel 1 and the rotation angle of the output shaft 8 are detected.

Hereinafter, the operation of the steering device having such a configuration will be described. When the input shaft 5 and the output shaft 8 rotate, the input shaft 5, the output shaft 8 and the connecting shaft 6 rotate. As the input shaft 5 and the output shaft 8 rotate, the MR sensors 39, 41
An MR sensor (not shown) detects the strongest point in the axial direction of the magnetic field formed in the vicinity of the peripheral surfaces 13a and 13b by the projections 32a and 32b and 34a and 34b, and supplies the voltage signal to the control unit. . The control unit detects the rotation angles of the input shaft 5 and the output shaft 8 based on the applied voltage signals, similarly to the signal processing unit 35 described in the second embodiment.

Here, if a steering torque is applied to the steering wheel 1 and a twist angle is generated in the connecting shaft 6, the rotation angles of the input shaft 5 and the output shaft 8 are different from each other, and the difference is the twist angle. . The control unit can detect the steering torque applied to the steering wheel 1 from the twist angle. The control unit controls the electric motor 1 based on the detected steering torque and the rotation angle of the output shaft 8.
4 is performed. Note that the present invention is not limited to the above embodiments. For example, a protrusion made of a magnetic material
A portion made of a magnetic material may be formed on the input shaft made of a non-magnetic material, or the configuration may be reversed.

[0045]

According to the rotation angle detecting device according to the first aspect of the present invention, a stable output of the magnetic sensor can be obtained, and the magnetically discontinuous portion is parallel to the peripheral surface of the rotating shaft. Since it is provided intermittently in a linear manner, it is possible to realize a rotation angle detection device that is easy to work.

According to the rotation angle detecting device according to the second aspect of the present invention, a stable output of the magnetic sensor can be obtained, and the projections are provided intermittently in a parallel line along the peripheral surface of the rotating shaft. Therefore, it is possible to realize a rotation angle detection device that is easy to work.

According to the rotation angle detecting device according to the third aspect of the present invention, a stable periodic output of the magnetic sensor can be obtained, and the magnetically discontinuous portion extends along the peripheral surface of the rotating shaft. Since it is provided intermittently in parallel lines, it is possible to realize a rotation angle detection device that is easy to work.

According to the rotation angle detecting device according to the fourth aspect of the invention, the rotation angle during one cycle of each detection signal can be specified from the relationship between the detection signals of the first magnetic sensor and the second magnetic sensor. In addition, a stable periodic output of the magnetic sensor can be obtained, and magnetically discontinuous portions are provided intermittently in parallel lines along the peripheral surface of the rotating shaft, so that machining is easy. A certain rotation angle detecting device can be realized.

According to the torque sensor of the fifth aspect, a stable output of the magnetic sensor can be obtained, and the magnetically discontinuous portion is intermittently formed in a parallel line along the peripheral surface of the rotating shaft. Therefore, a torque sensor that can be easily manufactured can be realized.

According to the steering device of the sixth aspect, the first to first steering devices are provided.
A steering device using the rotation angle detection device according to any one of the four inventions and the torque sensor according to the fifth invention can be realized.

[Brief description of the drawings]

FIG. 1 is a principle diagram showing a main configuration of a rotation angle detecting device according to an embodiment of the present invention.

FIG. 2 is an explanatory diagram for explaining a projection (projection) made of a magnetic material and an MR sensor.

FIG. 3 is an explanatory diagram for explaining an operation of the rotation angle detection device shown in FIG. 1;

FIG. 4 is a principle view showing a main part configuration of an embodiment of a torque sensor according to the present invention.

FIG. 5 is a longitudinal sectional view showing a configuration of a main part of an embodiment of the steering device according to the present invention.

FIG. 6 is a principle diagram showing an example of a configuration of a main part of a conventional rotation angle detection device.

FIG. 7 is an explanatory diagram for explaining an operation of the rotation angle detection device shown in FIG. 6;

[Explanation of symbols]

1, 20, 30 Steering wheel 2 Upper shaft 5 Input shaft 6, 37 Connecting shaft (torsion bar) 8 Output shaft 13 Torque sensor 13a, 13b Peripheral surface 22a, 22b, 32a, 32b, 34a, 34b Projection made of magnetic material Object (projection, magnetically discontinuous portion) 25, 39, 41 MR sensor (magnetoresistive element, first magnetic sensor) 26, 40, 42 MR sensor (magnetoresistive element, second magnetic sensor) 14 electric Motor 21 Steering shaft (steering shaft, rotating shaft) 27, 35 Signal processing unit 31 Upper shaft (input shaft) 33 Lower shaft (output shaft)

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2F051 AA01 AB06 AC01 2F063 AA35 BA08 BB05 BC03 BD16 CA08 CA40 DA01 DA04 DB07 DC08 DD03 DD05 GA52 GA73 LA17 2F077 AA21 JJ02 JJ07 JJ21 3D033 CA28 CA29

Claims (6)

[Claims] 1. A portion which is provided intermittently in a parallel line along a peripheral surface of a rotating shaft and which is magnetically discontinuous in a direction of the rotating shaft and a first magnetic field to detect a magnetic field formed by the portion. A rotation angle detection device for detecting a displacement angle of the rotation axis of the rotation shaft from the first magnetic sensor based on a detection signal of the first magnetic sensor. 2. The rotation angle detecting device according to claim 1, wherein the magnetically discontinuous portion is a protrusion or a depression made of a magnetic material. 3. The rotation angle detecting device according to claim 1, wherein the magnetically discontinuous portions are provided alternately in parallel lines and at equal intervals in the rotation direction. A second magnetic sensor configured to detect a magnetic field formed by the portion at a position different from the first magnetic sensor by a predetermined angle in the rotational direction, the second magnetic sensor and the first magnetic sensor. The rotation angle detection device according to claim 1 or 2, wherein the displacement angle is detected based on each detection signal of a sensor. 5. A torque sensor for detecting a torque applied to an input shaft by a torsion angle generated in a connecting shaft connecting the input shaft and the output shaft, wherein the torque sensor is attached to each of the input shaft and the output shaft.
A rotation angle detection device according to any one of (1) to (4), and means for detecting a difference between the displacement angles detected by the rotation angle detection device. The difference between the displacement angles detected by the means is defined as the twist angle. A torque sensor characterized by what it does. 6. An input shaft connected to a steered wheel, an electric motor for steering assistance driven and controlled based on a steering torque applied to the steered wheel, an output shaft interlocked with the electric motor, and a steering applied to the input shaft. 6. The torque sensor according to claim 5, wherein the torque is detected by a torsion angle generated in a connecting shaft connecting the input shaft and the output shaft, and the steering angle of the steered wheels is detected by a rotation angle detecting device included in the torque sensor. A steering device characterized in that the steering device is detected.