JP2003004438A - Rotation angle detector and steering apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rotation angle detector and a steering apparatus which detects absolute rotation angle from a specified reference angle position with high accuracy. SOLUTION: The detector comprises magnetic sensors 1A, 1B, disposed in parallel in the rotating direction of a body of rotation 14 and an arithmetic processor 4 for selecting either the magnetic sensor 1A or 1B, and detects the absolute rotation angle of the body of rotation 14, based on the position detected by the selected sensor 1A or 1B.

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 of a rotating body, and a steering device equipped with a torque detecting device using the rotation angle detecting device.

[0002]

2. Description of the Related Art As a steering apparatus for an automobile, there is a steering apparatus that drives an electric motor to assist steering and reduce the burden on the driver. This steering device includes a first rotating shaft (input shaft) connected to a steering wheel (steering wheel), a second rotating shaft (output shaft) connected to a steering mechanism, and a connecting shaft (connecting an input shaft and an output shaft). A torque bar, and a torque detection device detects a torque (steering torque) applied to the input shaft, and based on the detected torque, drive controls an electric motor to assist steering. Further, the steering angle midpoint of the steered wheels is obtained by the rotation angle detection device, and the drive control of the electric motor is also performed according to the steered angle of the steered wheels.

FIG. 11 shows an example of the essential structure of a rotation angle detecting device. This rotation angle detection device shows a case where it is used for a steering device, and rotates around a rotary shaft 26 to which a steering wheel 20 is connected at the upper end side and a pinion 23 (steering mechanism) is connected at the lower end side. The magnetic target (object to be detected) 22 is spirally formed along the peripheral surface of the rotating body 21.
Is provided. Further, in order to detect the part of the target 22 that moves in the direction of the rotary shaft 26 when the rotating body 21 rotates, the part detecting means (magnetic sensor: magnetoresistive effect element) 24 forms an appropriate gap with the rotating body 21. It is provided empty. The magnetic sensor 24 is fixed to a stationary part of the vehicle body.

The magnetic sensor 24 has a voltage dividing circuit including, for example, two magnetic resistors, and outputs the divided voltage. Further, the magnetic sensor 24 includes a bias magnet on the side not facing the rotating body 21 in order to increase the sensitivity by increasing the change in the magnetic field due to the target 22 made of a magnetic body,
The magnetic field on the surface of the rotating body 21 is strengthened. In the rotation angle detecting device having such a configuration, the rotating body 21 (rotating shaft 26) is
The portion of the target 22 that is close to the detection surface of the magnetic sensor 24 in response to the rotation in the range of 0 <θ <360 °
It changes in the direction along the rotation axis 26.

The part of the target 22 that is close to the detection surface of the magnetic sensor 24 corresponds to the rotation angle of the rotating body 21, and as shown in FIG.
If the target 22 is provided so that the output voltage of the rotary body 21 and the rotation angle of the rotary body 21 have a linear relationship, the arithmetic processing unit 40 calculates the rotary body 21 (rotary shaft) based on the output voltage of the magnetic sensor 24. The rotation angle (steering angle θ) of 26) can be detected.

FIG. 13 shows an example of the essential structure of a torque detecting device having the above-described rotation angle detecting device. This torque detection device is used for a steering device, and rotates about an input shaft 35 having a steering wheel 30 connected to the upper end side and a connection shaft (torsion bar) 37 connected to the lower end side. Spiral along the peripheral surface of the rotating body 31,
A magnetic target 32 is provided. Also, the rotating body 3
In order to detect the portion of the target 32 that moves in the direction along the input shaft 35 when 1 rotates, the magnetic sensor A
Are provided with an appropriate gap from the rotating body 31.

Similarly, the upper end side is connected to the torsion bar 37, and the lower end side is spirally formed along the peripheral surface of the rotating body 33 rotating around the output shaft 36 connected to the pinion 38 (steering mechanism). A magnetic target 34 is provided.
Further, in order to detect the part of the target 34 that moves in the direction along the output shaft 36 when the rotating body 33 rotates, the magnetic sensor B is provided with an appropriate gap with the rotating body 33.

In the torque detecting device having such a configuration, the targets 32 and 34 which are close to the detection surfaces of the magnetic sensors A and B as the rotating body 31 and the rotating body 33 rotate.
Moves in the direction of the input shaft 35 (output shaft 36).
Target 3 close to the detection surfaces of magnetic sensors A and B
Rotating body 31 (input shaft 35) based on 2, 34 parts
Also, the rotation angle of the rotating body 33 (output shaft 36) can be detected.

For example, when the targets 32 and 34 are provided so that the output voltages of the magnetic sensors A and B and the rotation angles of the rotating bodies 31 and 33 have the same linear relationship, the rotating body 31 and the rotating body are When 33 rotates multiple times,
As shown in FIGS. 14A and 14B, the magnetic sensors A and B output voltage waveforms of a 360 ° cycle, and the output voltage causes the rotor 31 (input shaft 35) and the rotor 33 to rotate.
The rotation angles θm and θv of the (output shaft 36) can be detected.

If torque (steering torque) is applied to the steering wheel 30 and a torsion angle is generated in the torsion bar 37, the output voltages of the magnetic sensors A and B are shown in, for example, FIG. 14 (c). As described above, since the voltage difference ΔV corresponding to the twist angle is generated, the voltage difference ΔV
Can be calculated by the arithmetic processing unit 40 to obtain the twist angle, and a signal indicating the torque can be output. Magnetic sensor B
Is output as a signal indicating the rotation angle (steering angle) of the output shaft 36. Further, the output voltage of the magnetic sensor A can be output as a signal indicating the rotation angle of the input shaft 35.

[0011]

Targets 22 and 3
Since 2 and 34 are formed in a spiral shape, the both ends are discontinuous. 12 (a), (b) and FIG. 14 (a),
As shown in (b) and (c), one rotation cycle (0 °, 36
0 °, 720 °), the linearity of the output signal of the magnetic sensor deteriorates. The detection accuracy of the rotation angle at the discontinuous portion where the linearity deteriorates becomes low.

Further, FIGS. 12 (a), (b) and FIG.
As shown in (a), (b), (c), since the rotation angle of 0 ° to 360 ° is assigned to the amplitude of the output signal of the magnetic sensor, the change of the output signal with respect to the change of the rotation angle becomes small, and the rotation of the rotation signal is reduced. The angle detection accuracy is low.

The present invention has been made in view of the above circumstances, and an object thereof is to provide a rotation angle detection device and a steering device that can detect an absolute rotation angle with reference to a predetermined angle position with high accuracy. To do.

[0014]

According to a first aspect of the present invention, there is provided a rotation angle detecting device for detecting a position of a first object to be detected, a first part detecting means, and a rotation axis. A first rotating body provided with the first detected object so that the position detected by the first part detecting means changes, and the first rotating body based on the position detected by the first part detecting means. Angle detecting means for detecting a rotation angle of the first rotating body, the first detected body is provided so that a position detected by the first part detecting means is different during one rotation of the first rotating body. In a rotation angle detecting device for detecting an absolute rotation angle based on a predetermined angular position of one rotating body, in the rotation direction of the first rotating body, the first portion detecting means is provided in parallel with the first portion detecting means. 1 second part detecting means for detecting the position of the object to be detected; Selecting means for selecting either one of the second part detecting means, wherein the angle detecting means is based on the position of the first detected object detected by the selected first or second part detecting means. It is designed to detect the absolute rotation angle of the first rotating body.

In such a rotation angle detecting device, the first and second part detecting means are arranged side by side in the rotation direction of the first rotating body, so that a detection signal having a predetermined phase difference is output from both the part detecting means. Is output. The selection means can detect the absolute rotation angle based on either one of the two detection signals. For example, when the first target is provided so that the detection signals output from the first and second part detecting means are proportional to the absolute rotation angle, most of the detection signals are linear, but there are also parts that are non-linear. To do. In particular, the detection signal near the end of the first target is often non-linear. In order not to use such a non-linear part for angle detection, the first
Alternatively, by selecting the second portion detecting means, it is possible to detect the absolute rotation angle with high accuracy using the linear portion.

The rotation angle detecting device according to claim 2 is the first
The first part detection means for detecting the position of the detection object and the first detection part rotate so that the position detected by the first part detection means changes in response to the rotation. A first rotating body is provided, and an angle detecting means for detecting a rotation angle of the first rotating body based on the position detected by the first part detecting means is provided, and the first rotating body makes one rotation. The first object to be detected is provided so that the positions detected by the first part detecting means are different from each other, and the rotation is made to detect an absolute rotation angle based on a predetermined angular position of the first rotating body. In the angle detecting device, a second part detecting means for detecting a position of a second detected object, and a second part detecting means for integrally rotating with the first rotating body around the rotation axis, and according to the rotation, the second part detecting means. The second object is provided so that the position detected by A second rotary member, and a selection means for selecting one of said first and second parts detecting means, said angle detection means, the selected first or second
The absolute rotation angle of the first rotating body or the rotation angle of the second rotating body is detected based on the position of the first or second detected body detected by the part detecting means. And

In such a rotation angle detecting device, the second portion detecting means detects the position of the proximity portion of the second target provided on the second rotating body connected to the first rotating body, whereby When the detection signal output from the part detection means is non-linear, the selection can be changed to the detection signal output from the second part detection means. The second target is the first
When the detection signal output from the part detection means is non-linear,
It is provided so that the detection signal output from the second part detection means is linear.

According to a third aspect of the present invention, there is provided a rotation angle detecting device according to the second aspect, wherein the second detected body has a position detected by the second portion detecting means while the second rotary body makes one rotation. Differently provided, the angle detecting means is configured to detect an absolute rotation angle with reference to a predetermined angular position of the second rotating body.

Since such a rotation angle detecting device can detect the absolute rotation angle based on the detection signal output from the second part detecting means, the first and second part detecting means are selectively switched to perform the absolute rotation. The angle can be detected.
The same thing can be used for a 1st target and a 1st rotating body and a 2nd target and a 2nd rotating body. In this case, the first rotating body and the second rotating body are provided on the rotating shaft so that the detection signals output from the first and second part detecting means have a phase difference.

A rotation angle detecting device according to a fourth aspect is the rotation angle detecting device according to any one of the first to third aspects, wherein the selecting means is the selected first or second part detecting means of the first or second detected object. A means for determining that the position of the predetermined portion is detected is provided, and when it is determined that the position of the predetermined portion is detected, the selection should be changed to the unselected second or first portion detection means. It is characterized by being.

Such a rotation angle detecting device is, for example,
When the first and second targets are provided so that the detection signals output by the first and second part detection means are proportional to the absolute rotation angle, the predetermined part is set based on the part that changes from linear to non-linear. Thereby, the selection can be changed to the other part detecting means before it becomes non-linear.

According to a fifth aspect of the present invention, there is provided the rotation angle detecting device according to the second aspect, wherein the second object to be detected has a position detected by the second portion detecting means while the second rotating body makes one rotation. When the selection is changed from the first part detecting means to the second part detecting means, the angle detecting means is provided so as to repeat a predetermined change, and the second rotating body is based on the angular position at the time of change. Is detected, and the absolute rotation angle of the first rotating body is detected based on the detected rotation angle.

Such a rotation angle detecting device is, for example,
The selection unit changes the selection to the second region detection unit only while the detection signal output from the first region detection unit is non-linear. By detecting the rotation angle based on the angular position when the selection is changed to the second part detection means, the absolute rotation angle can be continuously detected. The second target is provided such that the detection signal output from the second part detection unit is linear while the detection signal output from the first part detection unit is non-linear.

According to a sixth aspect of the present invention, there is provided the rotation angle detecting device according to the fifth aspect, wherein the selecting means detects the position of a predetermined range portion of the first object to be detected by the first part detecting means. It is characterized in that a means for judging is provided, and while it is judged that the position of the predetermined range portion is being detected, the selection is changed to the second part detecting means.

Such a rotation angle detecting device is, for example,
When the first target is provided so that the detection signals output by the first and second part detecting means are proportional to the absolute rotation angle,
By setting the predetermined range based on the non-linear portion, the selection can be switched to the second portion detecting means while the detection signal detected by the first portion detecting means becomes non-linear. When the detection signal detected by the first part detecting means returns to a linear shape, the selection of the second part detecting means is canceled and the first part detecting means is selected.

According to a seventh aspect of the rotation angle detecting device,
The first part detection means for detecting the position of the detection object and the first detection part rotate so that the position detected by the first part detection means changes in response to the rotation. A first rotating body is provided, and an angle detecting means for detecting a rotation angle of the first rotating body based on the position detected by the first part detecting means is provided, and the first rotating body makes one rotation. The first object to be detected is provided so that the positions detected by the first part detecting means are different from each other, and the rotation is made to detect an absolute rotation angle based on a predetermined angular position of the first rotating body. In the angle detecting device, a second part detecting means for detecting a position of a second detected object, and a second part detecting means for integrally rotating with the first rotating body around the rotation axis, and according to the rotation, the second part detecting means. The second object is provided so that the position detected by A second rotating body, and the second detected body is provided so that a position detected by the second part detecting means repeats a predetermined change while the second rotating body makes one rotation, The detecting means is adapted to detect the absolute rotation angle of the first and second rotating bodies based on the correspondence between the positions detected by the first and second part detecting means, respectively.

Such a rotation angle detecting device is, for example,
When the first target and the second target are provided so that the detection signals output by the first and second part detection means are proportional to the absolute rotation angle and the rotation angle (displacement rotation angle), the detection signal for a change in the absolute rotation angle Is smaller than the change rate of the detection signal with respect to the change of the displacement rotation angle, and the displacement rotation angle can be detected more accurately. The detection signal of the displacement rotation angle repeats a predetermined change, and therefore, the predetermined change is made 4 times while the first and second rotating bodies make one rotation, for example.
By providing the second target so as to repeat,
The predetermined change can be made to correspond to an absolute rotation angle of 0 ° to 89 °, 90 ° to 179 °, 180 ° to 269 °, 270 ° to 359 °. 0 ° to 89 °, 90 ° to 179 °, 180 ° to 2 based on the detection signal of the first part detecting means.
By specifying either 69 ° or 270 ° to 359 °, it is possible to detect the absolute rotation angle based on the detection signal of the second portion detecting means.

A rotation angle detecting device according to an eighth aspect is the rotation angle detecting device according to the seventh aspect, wherein the angle detecting means includes the first and second angles.
A storage unit is provided for storing the correspondence relationship between the positions of the first and second detection objects respectively detected by the part detection means.
It is characterized in that the absolute rotation angle is detected from the position detected by the second part detection means based on the position detected by the part detection means and the correspondence relationship stored in the storage section.

In such a rotation angle detecting device, for example, the second target is provided so as to repeat the predetermined change four times while the first and second rotating bodies make one revolution, and the predetermined change is 0 ° to 0 °.
89 °, 90 ° ~ 179 °, 180 ° ~ 269 °, 27
It corresponds to the absolute rotation angle of 0 ° to 359 °. Since this correspondence is stored in the storage unit, the displacement rotation angle is 5
In degrees, the absolute rotation angle is 5 °, 95 °, 185 °, 2
It can be detected to be any of 75 °, and any of 5 °, 95 °, 185 °, and 275 ° can be specified from the detection signal of the first portion detecting means.

A rotation angle detecting device according to a ninth aspect is the rotation angle detecting device according to any one of the first to eighth aspects, wherein the first or second object to be detected is a magnetic body and the first or second part detecting means is a magnetic body. It is a sensor.

In such a rotation angle detecting device, since the magnetic sensor detects the portion of the magnetic body to be detected (target), the structure of the portion detecting means is simple and the cost is low, and the adjusting operation is also performed. It will be easier. Further, the target site can be detected without contact.

According to a tenth aspect of the present invention, in the rotation angle detecting device according to any one of the first to ninth aspects, as the first or second rotating body rotates, the first or second part detecting means moves the first or second portion detecting means. Alternatively, the first or second object to be detected is provided so that a distance to a proximity portion of the second object to be detected changes.

In such a rotation angle detecting device, the portion of the object to be detected (target), which is close to the portion detecting means, changes in the axial direction of the rotation axis in accordance with the rotation of the rotating body. The absolute rotation angle of the rotating body can be detected.

According to an eleventh aspect of the present invention, in the rotation angle detecting device according to any one of the first to ninth aspects, the position detected by the first or second part detecting means as the first or second rotating body rotates. The first or second detected body is provided so that changes in the axial direction of the rotation axis of the first or second rotating body.

In such a rotation angle detecting device, the object to be detected (target) is detected from the part detecting means in accordance with the rotation of the rotating body.
Since the distance to the adjacent portion of the rotating body changes, the absolute rotation angle of the rotating body can be detected based on the distance between the target portion and the portion detecting means.

A steering device according to a twelfth aspect of the present invention includes a first rotating shaft connected to the steered wheels, and a second rotating shaft connected to the steering mechanism and coaxially with the first rotating shaft. Detecting the absolute rotation angles of the first and second rotation shafts respectively, or of the displacement rotation angle and the first and / or second rotation shafts with reference to an arbitrary angular position of the first and second rotation shafts. A first rotation angle detection device and a second rotation angle detection device for detecting an absolute rotation angle, and means for obtaining a difference between the detected absolute rotation angle or displacement rotation angle, and the difference between the absolute rotation angle or the displacement rotation angle. And a torque detection device that detects a torque applied to the first rotation shaft based on the detected torque and an electric motor that drives and controls the second rotation shaft based on the detected torque and the absolute rotation angle. A steering device comprising the first and second / Or second rotation angle detecting device is characterized by a rotation angle detecting apparatus according to any one of claims 1 to 11.

Such a steering apparatus is provided with the torque detecting device using the rotation angle device for detecting the absolute rotation angle of the first rotating shaft and / or the second rotating shaft described above,
In addition to torque, drive control of the electric motor can be performed based on the absolute rotation angle. The absolute rotation angle can be a rotation angle based on the angle when the vehicle goes straight.

[0038]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be specifically described below with reference to the drawings showing the embodiments thereof.

(First Embodiment) FIG. 1 shows a structural example of a rotation angle detecting device according to the present invention. The rotation angle detection device rotates around a magnetic sensor (site detection means) 1A that detects the position of a proximity portion of a target (object to be detected) 14t, and a rotation shaft (input shaft 35), and the magnetic sensor according to the rotation. Target 1 so that the position detected by 1A changes
4t is provided, and the angle detection means (arithmetic processing unit 4) that detects the rotation angle of the rotor 14 based on the detected position. The target 14t is provided so that the position detected by the magnetic sensor 1A is different while the rotating body 14 makes one rotation, and the absolute rotation angle with respect to the predetermined angular position of the rotating body 14 can be detected. The target 14t is provided so that the position detected by the magnetic sensor 1A changes in the direction along the input shaft 35 as the rotating body 14 rotates.

The rotation angle detecting device includes a magnetic sensor (site detecting means) 1B arranged in parallel with the magnetic sensor 1A in the rotation direction of the rotating body 14, and the arithmetic processing section 4 includes the magnetic sensors 1A,
It operates as a means for selecting either one of 1B. From the magnetic sensors 1A and 1B, for example, as shown in FIG.
Detection signals V1A and V1B having a phase difference are output.
The arithmetic processing unit 4 detects the absolute rotation angle of the rotating body 14 based on the position detected by the selected magnetic sensor 1A or 1B. Here, the absolute rotation angle is a rotation angle with reference to a predetermined angular position, and for example, the rotation angle of the input shaft 35 with respect to the angular position when the vehicle goes straight is detected.

The arithmetic processing unit 4 uses the selected magnetic sensor 1A.
Alternatively, the detection signal V1A or V1B of 1B is applied to the target 14
It operates as a means for determining that the position of a predetermined portion of t has been detected. For example, as shown in FIG. 2, it is possible to determine the detection of the position of the predetermined portion of the target 14t when the predetermined value (displayed by the broken line) is reached. This predetermined value is set based on the detection value immediately before the detection signals V1A and V1B become non-linear. When the selected detection signal V1A or V1B reaches a predetermined value, the arithmetic processing unit 4 changes the selection to the unselected detection signal V1B or V1A.

Next, the operation of the rotation angle detecting device having such a configuration will be described. When the input shaft 35 (rotating body 14) rotates, the magnetic sensors 1A and 1B output detection signals V1A and V1B having a phase difference. Arithmetic processing unit 4
Selects one of the detection signals V1A and V1B,
The absolute rotation angle is detected based on the selected detection signal V1A or V1B. Selected detection signal V1A or V1B
When reaches a predetermined value, the arithmetic processing unit 4 changes the selection to the unselected detection signal V1B or V1A. By selecting the magnetic sensors 1A and 1B, the detection signal V1
Since the rotation angle can be detected using the linear portions of A and V1B, it is possible to detect the absolute rotation angle with high accuracy.

(Second Embodiment) FIG. 3 shows an example of the configuration of a rotation angle detecting device according to the present invention. The rotation angle detection device is similar to the rotation body 14 of the rotation angle detection device of the first embodiment shown in FIG. 1, the rotation body 14 provided with the target 14t, the magnetic sensor 1A, and the arithmetic processing unit 4. With. The target 14t is provided so that the position detected by the magnetic sensor 1A is different while the rotating body 14 makes one rotation, and detects the absolute rotation angle with the predetermined angular position of the rotating body 14 as a reference.

The rotation angle detecting device rotates integrally with the rotating body 14 around the input shaft 35 and the magnetic sensor 1B (site detecting means) for detecting the position of the target (detected body) 18t, and responds to the rotation. The rotating body 1 provided with the target 18t so that the position detected by the magnetic sensor 1B changes.
8 and selection means (arithmetic processing unit 4) for selecting one of the magnetic sensors 1A and 1B.

While the rotating body 18 makes one revolution, the magnetic sensor 1
The target 18t is provided so that the position detected by B differs, and it is possible to detect the absolute rotation angle with respect to the predetermined angular position of the rotating body 18. Rotor 14,
Targets 14t and 18t are provided so that the positions detected by the magnetic sensors 1A and 1B change in the axial direction of the input shaft 35 as the 18 rotates. Rotating body 14, 1
8 can use the same thing, and magnetic sensor 1A,
The rotating bodies 14 and 18 are provided on the input shaft 35 so that the detection signals V1A and V1B detected by 1B have a predetermined phase difference. The detection signals V1A and V1B are the same as in FIG.

The arithmetic processing unit 4 is connected to the selected magnetic sensor 1A.
Alternatively, the absolute rotation angle of the input shaft 35 provided with the rotating bodies 14 and 18 is detected based on the detection signal V1A or V1B output from 1B. The arithmetic processing unit 4 operates as means for detecting that the selected detection signal V1A or V1B has reached a predetermined value (broken line in FIG. 2), and when it reaches the predetermined value, the unselected detection signal V1B or Change selection to V1A. Since the detection signals V1A and V1B are the same as those in FIG. 2, the operation of the rotation angle detecting device is also the same as in the first embodiment.

The rotation angle detecting device described in the first embodiment or the second embodiment can be provided in the torque detecting device of the steering device. The torque detection device includes a rotation angle of an input shaft (first rotation shaft) connected to the steered wheels and an output shaft (second rotation shaft) connected to the steering mechanism and coaxially with the input shaft. The torque applied to the input shaft is detected based on the difference from the rotation angle. By using the rotation angle detection device of the present invention, an absolute rotation angle of the input shaft and / or the output shaft can be detected in addition to the torque, and an electric motor that assists the rotation of the output shaft based on the torque and the absolute rotation angle can be provided. Drive control becomes possible.

(Third Embodiment) In the rotation angle detecting device shown in FIG. 3, the position change of the target 18t detected by the magnetic sensor 1B is periodically changed while the input shaft 35 makes one rotation. You can also For example, as shown in FIG. 4, while the rotating body 12 makes one rotation, the magnetic sensor 1
The target 12t is provided so that the position detected by A repeats a predetermined change as shown in FIG. 5B, and the rotation angle (displacement rotation angle) with respect to the arbitrary angular position is detected.
In the example shown in FIG. 4, the rotating body 12 has a gear shape, and the outer peripheral portion (tooth portion) of the rotating body 12 is used as the target 12t. In addition, the target 14 provided on the rotating body 14
The position of t is detected by the magnetic sensor 1C.

The arithmetic processing section 8 operates as a means for discriminating that the magnetic sensor 1C detects the position of the target 14t within a predetermined range, and the magnetic sensor 1C is provided while the detection of the position within the predetermined range is discriminated. Change selection to 1A. The predetermined range can be set, for example, in the non-linear portion of the detection signal V1C of the magnetic sensor 1C shown in FIG.
The rotary body 12 is provided on the input shaft 35 so that the detection signal V1A output from the magnetic sensor 1A becomes linear when the detection signal V1C output from the magnetic sensor 1C becomes non-linear. As the rotating body 12 rotates, the magnetic sensor 1
The target 12t is provided so that the distance between A and the adjacent portion of the target 12t changes.

Next, the operation of the rotation angle detecting device having such a configuration will be described. When the input shaft 35 (rotating body 14) rotates, the detection signal V1C is output from the magnetic sensor 1C. The arithmetic processing unit 8 detects the absolute rotation angle based on the detection signal V1C. When the detection signal V1C becomes non-linear, the arithmetic processing unit 8 changes the selection to the detection signal V1A output from the magnetic sensor 1A. Arithmetic processing unit 8
When the selection is changed to the detection signal V1C, the absolute rotation angle is detected by adding the displacement rotation angle based on the angular position when the selection is changed to the absolute rotation angle when the selection is changed. When the detection signal V1C returns to linear, the arithmetic processing unit 8 deselects the detection signal V1A and selects the detection signal V1C.

As shown in FIG. 6, the magnetic sensors 1A and 1B for detecting the target 12t of the rotating body 12 are connected to the rotating body 1.
It can also be installed side by side in the direction of rotation 2. Magnetic sensor 1
As shown in FIG. 7B, detection signals V1A and V1B having a phase difference are output from A and 1B. Detection signal V
1A and V1B can be selected by the arithmetic processing unit 8 so that the non-linear portion is not used, as in the first embodiment (FIG. 2). Magnetic sensor 1 shown in FIG.
When the C detection signal V1C is non-linear, the detection signals V1A,
The linear one of V1B is selected.

In the above-described embodiment, the target 14
Although the portion of t is changed in the axial direction of the input shaft 35, as shown in FIG.
It is also possible to change the distance to the adjacent portion of the outer target 52t. Further, in the above-described embodiment, the outer circumference of the rotating body 12 is used as the target 12t, but the target 54t may be formed on the outer circumference of the rotating body 54 as shown in FIG. 8B. Furthermore, in the above-described embodiment, the target is detected using the magnetic sensor, but the detection of the target is not limited to the magnetic sensor, and the position of the target or the position of the target using any position detection sensor such as an optical sensor is detected. The distance to the target can be detected.

(Fourth Embodiment) FIG. 9 shows an example of the structure of a steering apparatus equipped with a rotation angle detecting device according to the present invention. The steering device is connected to an input shaft (first rotation shaft) 35 connected to a steering wheel (steering wheel) 30 and a pinion (steering mechanism) 38, and is also input via a torsion bar 37 (connection shaft). Output shaft 3 coaxially connected to shaft 35
6 and two rotation angle detecting devices for respectively detecting rotation angles including the absolute rotation angles of the input shaft 35 and the output shaft 36, and means for obtaining a difference between the detected rotation angles, based on the difference between the rotation angles. A torque detection device that detects the torque applied to the input shaft 35 and an electric motor (not shown) that assists the rotation of the output shaft 36 and is drive-controlled based on the detected torque and the absolute rotation angle are provided.

The rotation angle detecting device on the input shaft 35 side includes a magnetic sensor (site detecting means) 1C for detecting the position of a proximity portion of a target (detection object) 44t, and a rotation shaft (input shaft 3).
5) The center of rotation of the rotary body 44 is provided with a target 44t so as to change the position detected by the magnetic sensor 1C according to the rotation, and the rotation angle of the rotary body 44 based on the detected position. Angle detecting means for detecting (arithmetic processing unit 4
8) and. The target 44 is made so that the position detected by the magnetic sensor 1C is different during one rotation of the rotating body 44
t is provided, and the absolute rotation angle with respect to the predetermined angular position is detected.

Further, magnetic sensors (site detecting means) 1A, 1B for detecting the position of the target (object to be detected) 42t.
And a rotary body 42 provided with a target 42t so as to rotate integrally with the rotary body 44 around the rotary shaft (input shaft 35) and the positions detected by the magnetic sensors 1A and 1B change according to the rotation. With. The target 42t is provided so that the position detected by the magnetic sensor 1A (1B) repeats a predetermined change while the rotating body 42 makes one rotation, and the displacement rotation angle based on the arbitrary angle position is detected. Rotating bodies 42, 4
4 rotates, magnetic sensors 1A (1B), 1C
The detection signals V1A (V1B) and V1C output from
The target 42 is changed so as to change in the axial direction of the input shaft 35.
t and 44t are provided. The arithmetic processing unit 48 detects the absolute rotation angle of the input shaft 35 based on the positions detected by the magnetic sensors 1A (1B) and 1C.

The arithmetic processing section 48 is arranged so that the magnetic sensor 1A (1
B), detection signals V1A (V1
B) and a storage unit that stores the correspondence relationship between V1C, and detects the absolute rotation angle based on the detection signal V1A or V1B from the absolute rotation angle detected by the detection signal V1C and the stored correspondence relationship.

For example, as shown in FIGS. 10A and 10B, the detection signal V1A (V
1B) repeats the predetermined change four times, and the angle when the predetermined change starts (changes from decrease to increase) corresponds to the absolute rotation angles 0 °, 89 °, 179 °, 269 °. , A target 42t is provided. This correspondence is stored in the storage unit of the arithmetic processing unit 48. Figure 10
In the example of (b), eight absolute rotation angles correspond to one detection signal value, but the eight absolute rotation angles are based on the absolute rotation angle obtained from the detection signal V1C shown in FIG. 10 (a). Either absolute rotation angle can be specified.

The rotation angle detecting device on the side of the output shaft 36 has magnetic sensors (site detecting means) 2A and 2B for detecting the position of a proximity portion of the target (object to be detected) 46t and a rotating shaft (output shaft 36) as the center. The magnetic sensor 2 rotates according to the rotation.
A rotating body 46 provided with a target 46t so that the positions detected by A and 2B change, and an angle detecting means (calculation) for detecting a rotation angle (displacement rotation angle) of the rotating body 46 based on the detected position. Processing unit 48). The target 46t is provided so that the position detected by the magnetic sensor 2A (2B) is different while the rotating body 46 makes one rotation, and the displacement rotation angle based on the arbitrary angular position is detected.

Here, the displacement rotation angle is a rotation angle with reference to an arbitrary angular position such as an angle at which the rotation is started, and is used for torque detection. In the present embodiment, the rotation angle is based on the angle at which the predetermined change is repeated (the angle at which the detection signal changes from decreasing to increasing). As shown in FIG. 14C, the torque is detected by detecting the detection signal 1A on the input shaft 35 side and the detection signal 2A on the output shaft 36 side.
The reference angle is not particularly limited as long as the difference ΔV between the input shaft 35 and the output shaft 36 can be detected as the displacement rotation angle.

Next, the operations of the rotation angle detecting device and the steering device having the above-mentioned configurations will be described. When the input shaft 35 is rotated by the operation of the steering wheel 30, the rotating bodies 42 and 44 are rotated, and the positions of the adjacent portions of the targets 42t and 44t detected by the magnetic sensors 1A (1B) and 1C are changed. Similarly, when the output shaft 36 rotates, the rotating body 46 also rotates, and the position of the near portion of the target 46t detected by the magnetic sensor 2A (2B) changes. The torque is detected based on the difference between the rotation angles of the input shaft 35 and the output shaft 36 obtained from the difference between the detection signals V1A and V2A.

Further, the absolute rotation angle corresponding to the detection signal V1A is obtained from the correspondence relationship stored in the arithmetic processing section 48. In the present embodiment, as shown in FIG.
Eight absolute rotation angles correspond to one detection value of the detection signal V1A. Based on the absolute rotation angle detected by the detection signal V1C, any one of the eight absolute rotation angles is specified to obtain the absolute rotation angle.

As shown in FIGS. 10A and 10B, the detection signal V1A has a larger rate of change of the detection signal with respect to the change of the rotation angle, and the absolute rotation angle is detected using the detection signal V1A. In this way, the absolute rotation angle can be detected more accurately than when the detection signal V1C is used.

[0063]

According to the rotation angle detecting device of the present invention, since the first and second part detecting means are arranged in parallel in the rotation direction of the first rotating body, it is possible to detect a predetermined phase difference from both the part detecting means. The signal is output. The selection means can detect the absolute rotation angle based on either one of the two detection signals. It is possible to detect the absolute rotation angle with high accuracy by selecting the linear part of the detection signal output from the first and second part detection means.

The rotation angle detecting device of the present invention is the first
In the case where the detection signal output from the first portion detecting means is non-linear by detecting the position of the proximity portion of the second target provided on the second rotating body connected to the rotating body by the second portion detecting means, The selection can be changed to a linear detection signal output from the second part detection means.

The rotation angle detecting device of the present invention is the second one.
By detecting the absolute rotation angle based on the detection signal output from the part detection means, the first and second part detection means can be selectively switched to detect the absolute rotation angle.

Further, the rotation angle detecting apparatus of the present invention can determine, for example, that the position of the portion where the detection signals output from the first and second part detecting means change from linear to nonlinear is detected. The selection of the part detecting means can be changed before it becomes non-linear.

The rotation angle detecting device of the present invention is the first
The selection can be switched to the second part detecting means while the detection signal output from the part detecting means is non-linear.

The rotation angle detecting device of the present invention is the first
By determining that the position of the non-linear range portion of the detection signal output from the second part detecting means is detected, the first part detecting means detects the position The selection can be switched to the two-site detecting means.

Further, the rotation angle detection device of the present invention can improve the detection accuracy of the absolute rotation angle by increasing the rate of change of the detection signal with respect to the change of the absolute rotation angle.

Further, the rotation angle detecting device of the present invention can detect the absolute rotation angle based on the displacement rotation angle by storing the displacement rotation angle in the storage unit in association with the change of the absolute rotation angle. .

Further, since the rotation angle detecting device of the present invention detects the target portion of the magnetic material by the magnetic sensor, the structure of the portion detecting means is simple and the cost is low, and the adjusting operation is easy. . Further, the target site can be detected without contact.

Further, according to the rotation angle detecting apparatus of the present invention, the portion of the object to be detected, which is close to the portion detecting means, changes in the axial direction of the rotation axis according to the rotation of the rotating body. The rotation angle of the rotating body can be detected.

Further, according to the rotation angle detecting apparatus of the present invention, the distance from the part detecting means to the adjacent part of the object to be detected changes according to the rotation of the rotating body, so that the distance between the part of the object to be detected and the part detecting means. The rotation angle of the rotating body can be detected based on

The steering apparatus of the present invention is provided with the torque detecting device using the above-described rotation angle device for detecting the absolute rotation angle, so that the electric motor for assisting rotation can be operated based on the absolute rotation angle in addition to the torque. Drive control can be performed.

[Brief description of drawings]

FIG. 1 is a diagram showing a configuration example of a rotation angle detection device according to the present invention.

2 is a diagram showing an example of a detection signal of the magnetic sensor shown in FIG.

FIG. 3 is a diagram showing another configuration example of the rotation angle detection device according to the present invention.

FIG. 4 is a diagram showing still another configuration example of the rotation angle detection device according to the present invention.

5 is a diagram showing an example of detection signals of the magnetic sensor shown in FIG.

FIG. 6 is a diagram showing still another configuration example of the rotation angle detection device according to the present invention.

7 is a diagram showing an example of detection signals of the magnetic sensor shown in FIG.

FIG. 8 is a schematic diagram showing another example of a rotating body and a target.

FIG. 9 is a diagram showing a configuration example of a rotation angle detection device and a steering device according to the present invention.

10 is a diagram showing an example of detection signals of the magnetic sensor shown in FIG.

FIG. 11 is a principle diagram showing a configuration example of a main part of a conventional rotation angle detection device.

FIG. 12 is an explanatory diagram for explaining the operation of the rotation angle detection device shown in FIG. 11.

FIG. 13 is a principle diagram showing a configuration example of a main part of a conventional torque detection device.

FIG. 14 is an explanatory diagram for explaining the operation of the torque detection device shown in FIG.

[Explanation of symbols]

1A, 1B, 1C, 2A, 2B Magnetic sensor (site detecting means) 4, 8, 48 Arithmetic processing section (angle detecting means) 12, 14, 18, 42, 44, 46, 52, 54 Rotating body 12t, 14t, 18t, 42t target (object to be detected) 44t, 46t, 52t, 54t target (object to be detected) 30 steering wheel (steering wheel) 38 pinion (steering mechanism) 35 input shaft (first rotating shaft) 36 output shaft (first) 2 rotation shafts) 37 torsion bar (connecting shaft)

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) G01D 5/245 G01D 5/245 V 3D033 G01L 3/10 G01L 3/10 B 5/22 5/22 F term (Reference) 2F051 AA01 AB05 BA03 2F063 AA35 AA36 BA08 CA10 DA05 DD03 EA03 GA52 KA01 KA05 2F069 AA83 AA86 BB40 GG04 GG06 GG12 GG13 GG63 GG64 CG65 DC29 Q29 3D27 NN3 2911

Claims (12)

[Claims] 1. A first part detecting means for detecting a position of a first object to be detected, and a first part detecting means for rotating about a rotation axis so that a position detected by the first part detecting means changes according to the rotation. A first rotating body provided with the first detected body; and angle detecting means for detecting a rotation angle of the first rotating body based on the position detected by the first part detecting means, 1
The first object to be detected is provided so that the position detected by the first part detecting means is different during one rotation of the rotating body, and the absolute rotation angle is detected with reference to the predetermined angular position of the first rotating body. In a rotation angle detection device that is configured to do so, a second portion detection unit that is arranged in parallel with the first portion detection unit in the rotation direction of the first rotating body and that detects the position of the first detected body, Selecting means for selecting one of the first and second part detecting means, wherein the angle detecting means detects the first object to be detected by the selected first or second part detecting means. The rotation angle detecting device is configured to detect the absolute rotation angle of the first rotating body based on the position. 2. A first part detecting means for detecting a position of a first object to be detected and a first part detecting part for rotating about a rotation axis so that a position detected by the first part detecting part changes according to the rotation. A first rotating body provided with the first detected body; and angle detecting means for detecting a rotation angle of the first rotating body based on the position detected by the first part detecting means, 1
The first object to be detected is provided so that the position detected by the first part detecting means is different during one rotation of the rotating body, and the absolute rotation angle is detected with reference to the predetermined angular position of the first rotating body. In a rotation angle detection device that is configured to do so, a second part detection unit that detects a position of a second detection target, and a first rotation member that rotates integrally with the rotation shaft as a center,
A second rotating body provided with the second object to be detected so that the position detected by the second part detecting means changes according to rotation; and one of the first and second part detecting means. Selecting means for selecting, the angle detecting means, based on the position of the first or second detected object detected by the selected first or second part detecting means, the first rotating body The absolute angle of rotation or the angle of rotation of the second rotating body is detected. 3. The second object to be detected is provided so that the position detected by the second part detecting means is different during one rotation of the second rotating body, and the angle detecting means is the first detecting means. The rotation angle detecting device according to claim 2, wherein the absolute rotation angle is detected with reference to a predetermined angular position of the two rotating bodies. 4. The selecting means selects the first or second selected.
The site detecting means includes means for determining that the position of the predetermined portion of the first or second detection target has been detected, and if it is determined that the position of the predetermined portion has been detected, the second portion not selected Alternatively, the rotation angle detecting device according to any one of claims 1 to 3, wherein the selection is changed to the first part detecting means. 5. The second object to be detected is provided such that the position detected by the second part detecting means repeats a predetermined change while the second rotating body makes one rotation, and the angle detecting means is provided. When the selection is changed from the first part detecting means to the second part detecting means, the rotation angle of the second rotating body is detected based on the changed angular position, and based on the detected rotation angle. The rotation angle detecting device according to claim 2, wherein the rotation angle detecting device is configured to detect an absolute rotation angle of the first rotating body. 6. The selecting means includes means for determining that the first part detecting means detects a position of a predetermined range portion of the first detected object, and detects the position of the predetermined range portion. 6. The rotation angle detecting device according to claim 5, wherein the selection is changed to the second part detecting means while it is determined that the rotation angle is being detected. 7. A first part detecting means for detecting a position of a first object to be detected and a first part detecting part for rotating about a rotation axis so that the position detected by the first part detecting part changes according to the rotation. A first rotating body provided with the first detected body; and angle detecting means for detecting a rotation angle of the first rotating body based on the position detected by the first part detecting means, 1
The first object to be detected is provided so that the position detected by the first part detecting means is different during one rotation of the rotating body, and the absolute rotation angle is detected with reference to the predetermined angular position of the first rotating body. In a rotation angle detection device that is configured to do so, a second part detection unit that detects a position of a second detection target, and a first rotation member that rotates integrally with the rotation shaft as a center,
A second rotating body provided with the second detected body so that a position detected by the second part detecting means changes according to rotation, and the second detected body is the second rotating body. The position detected by the second part detecting means is provided so as to repeat a predetermined change while the body makes one revolution, and the angle detecting means is provided with the first part.
And a rotation angle detecting device for detecting the absolute rotation angles of the first and second rotating bodies based on the correspondence between the positions detected by the second and second part detecting means, respectively. 8. The angle detecting means includes the first and second
A storage unit is provided for storing the correspondence relationship between the positions of the first and second detection objects respectively detected by the part detection means.
The absolute rotation angle is detected from the position detected by the second part detection means based on the position detected by the part detection means and the correspondence relationship stored in the storage section. Item 7. A rotation angle detecting device according to item 7. 9. The first or second object to be detected is a magnetic material, and the first or second part detecting means is a magnetic sensor. Rotation angle detection device. 10. The distance from the first or second part detecting means to the adjacent portion of the first or second object to be detected is changed as the first or second rotating body is rotated, The rotation angle detection device according to any one of claims 1 to 9, wherein the first or second detection target is provided. 11. As the first or second rotating body rotates, the position detected by the first or second part detecting means changes in the axial direction of the rotating shaft of the first or second rotating body. The rotation angle detection device according to any one of claims 1 to 9, wherein the first or second detection target is provided in the. 12. A first rotating shaft connected to a steered wheel, a second rotating shaft connected to a steering mechanism and coaxially connected to the first rotating shaft, and the first and second rotating shafts. Detecting the absolute rotation angle of the shaft, or detecting the displacement rotation angle and the absolute rotation angle of the first and / or second rotation shaft with reference to an arbitrary angular position of the first and second rotation shafts. A first rotation angle detection device and a second rotation angle detection device; and means for obtaining a difference between the detected absolute rotation angle or displacement rotation angle, and the first rotation axis based on the difference between the absolute rotation angle or the displacement rotation angle. A steering apparatus comprising: a torque detection device that detects a torque to be applied; and an electric motor that is driven and controlled based on the detected torque and an absolute rotation angle, and that assists rotation of the second rotary shaft. First and / or second rotation angle detection Device, according to claim 1
Steering device characterized by being the rotation angle detecting device according to any one of 1 to 11.