JPH02201116A - Rotation angle detector - Google Patents

Abstract

PURPOSE:To execute a rotation angle detection with high accuracy by comparing the detecting value of a void distance with the reference value of the void distance, feedback-controlling and driving a sensitive actuator by means of the signal of the difference. CONSTITUTION:A first magnetic sensor 23a is sensitized to a magnetic flux with a magnetic substance arranged on a first circumference, an output signal is outputted, and the rotation angle of a rotary shaft L is obtained based on the output signal. Simultaneously, a second magnetic sensor 23b is sensitized to the magnetic fluxes with the magnetic substances arranged on second and third circumferences. Since the magnetic substances arranged on the second and third circumferences have the same polarity and density, respectively, the number of magnetic fluxes, which the second magnetic sensor 23b sensitizes, does not depend on the rotation angle of a rotary disk 22, and it depends only on the void distance between the second magnetic sensor 23b and rotary disk 22. Consequently, by the output signal from the second magnetic sensor 23b, the above-mentioned void distance can be detected. Thus, the adjustment of the void distance at the time of fitting the rotary disk can be facilitated, and simultaneously, the rotation angle detection with high accuracy can be executed.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a rotation angle detection device using a position detection sensor.

(Prior Art) FIG. 3(^) is a front view showing an example of a rotation angle detection device using a conventional position detection sensor, and FIG. 3(B) is a plan view thereof. This rotation angle detection device includes a gear-shaped rotating disk 2 having periodic notches along the outer periphery and made of a magnetically permeable material, which is fitted into a rotating shaft 1. are designed to rotate as one.

Further, a magnetic sensor 3, which is a displacement detection sensor equipped with a magnetic bias circuit 6, is mounted on a sensor mounting portion 7 on a magnetic sensor support 5 with a predetermined gap from the outer peripheral surface of the rotating disk 2.

Figures 4(^) and (B) show another example of a rotation angle detection device using a conventional position detection sensor.
It is a front view and a plan view shown respectively corresponding to B), and the same components are given the same reference numerals and explanations are omitted. In this rotation angle detection device, magnetic bodies are arranged along the outer periphery of a rotating disk 12 in different polarity directions at regular intervals, and the magnetic flux from the lln magnetic body is caused by the magnetic sensor I3, which is a position detection sensor. It is now detected.

In each of these rotation angle detection devices, the magnetic sensor 3 or 13 outputs an output signal in response to changes in magnetic flux at regular intervals according to the rotation angle of the rotating disk 2 or 12, and the detection is based on this output signal. ) and find the rotation angle of rotation Ml.

(Problem to be Solved by the Invention) In order to maintain the detected rotation angle in the rotation angle detection device described above with high accuracy, it is necessary to maintain the relationship between the rotating disk 2 or 12 and the magnetic sensor 3 or 13 regardless of changes in the rotation angle. It is necessary to always keep the mutual aid of the voids constant.

However, when inserting the rotating disk 2 or 12 into the rotating IPlk+, the center of rotation of the rotating disk 2 or 12 and the center of rotation of the rotating shaft may become eccentric. The distance from the rotation center to the outer periphery of the rotating disk 2 or 12 varies depending on the rotation angle, and since the magnetic sensor 3 or 13 is fixed to the sensor mount 7, there is no electrical connection between the rotating disk 2 or 2 and the magnetic sensor 3 or 13. The gap distance to the sensor 3 or 13 also changes depending on the rotation angle. Therefore,
The output signal from the magnetic sensor 3 or 13 is not a perfectly periodic signal as shown in FIG. 5, and the amplitude varies depending on the rotation angle as shown in FIG. 6, causing problems such as distortion. . In addition, even if the rotating disk 2 or 12 is fitted into the rotation @1 without eccentricity, it is difficult to finely adjust the air gap distance between the 5 rotating disk 2 or 12 and the iJ magnetic sensor or 13 to a predetermined value. There were also problems.

The present invention was made in view of the above-mentioned circumstances, and an object of the present invention is to provide a rotation angle detection device that can always maintain the distance between the rotating disk and the position detection sensor at a reference value. It is about providing.

(Means for Solving the Problems) The present invention includes a rotating disk, a rotating disk arranged near the rotating disk,
The present invention relates to a rotation angle detection device comprising a position detection means for detecting a rotation angle of the rotating disk, and the above object of the present invention is a detection means for detecting a gap distance between the rotating disk and the position detection means. and the ti7 in the direction of changing the gap distance based on the detection signal from the detection means.
．． This is achieved by providing a fine movement means for finely moving the device testing device means and a drive control circuit thereof.

(Function) The rotation angle detection device using the position detection sensor of the present invention compares the detected value of the gap distance with the reference value of the gap distance, and uses the signal of the difference to feedback the command actuator t, IJ. Control and drive.

The rotation angle is detected by adjusting the gap distance to a reference value.

(Example) Figures 1 (8) and (81) show an example of a rotation angle detection device using the position detection sensor of the present invention, and Figures 4 (8) and (B)
) are a front view and a plan view respectively shown corresponding to
Identical constituent parts are given the same reference numerals and explanations will be omitted. In this rotation angle detection device, two magnetic sensors (hereinafter referred to as a first magnetic sensor 23a and a second magnetic sensor 23b) are installed side by side on a sensor mounting part 7, and this sensor mounting part 7 is a fine movement actuator. It is fixed to a magnetic sensor support 5 via an electrostrictive element 4 . In addition, the magnetic bodies are arranged at regular intervals along the outer circumference of the rotating disk 22 facing the first magnetic sensor 23a (hereinafter referred to as the first circumference), and in different polarity directions. , along the two outer circumferences (hereinafter referred to as the second circumference and the third circumference) of the rotating disk 22, where the 6n-type bodies with different polarities face the second magnetic sensor 23b, respectively. polarity and 6n
They are arranged so that the fields are the same.

In such a configuration, the first Iin air sensor 23a outputs an output signal in response to the ll7j east caused by the magnetic material arranged on the first circumference, and based on this output signal, the rotation of the rotating shaft load is controlled. Find the angle. At the same time, the second magnetic sensor 23b is sensitive to the Iin flux produced by the magnetic bodies arranged on the second and third circumferences. Since the magnetic bodies arranged on the second and third circumferences have the same polarity and density, the second magnetic sensor 23b, 6<the number of magnetic fluxes to be sensitive to the rotation of the rotating disk 22 It does not depend on the angle, but only on the gap distance between the second magnetic sensor 23b and the rotating disk 22. Therefore, the air gap distance can be detected by the output signal from the second magnetic sensor 23b. And the second
Based on the output signal from the 6n air sensor 23b, the electrostrictive element 4 can be driven to adjust the above-mentioned empty range bait to a reference value.

FIG. 2 is a block diagram showing an example of a drive control circuit that drives and controls the electrostrictive element 7-4 described above, and shows the reference value of the output signal %5^ from the second magnetic sensor 23b and the blank distance l2I11. A subtracter 32 calculates the difference DIFF between the base jp and the output signal SR from the No. 3 generator 31, which generates a signal corresponding to the output voltage of the second magnetic sensor 23b. , the calculated difference 0IFF is amplified by an amplifier 33 to a voltage necessary to drive the electrostrictive element 4, and is applied to the electrostrictive element 4. Therefore, due to the expansion and contraction of the electrostrictive element r4, The air gap distance 1111 between the first and second BN air sensors 23 and the rotating disk 22 is always set to a reference value.
It can also be used for fine adjustment of the gap distance when attaching 3a and 23b.

In the above-described embodiment, a rotating disk that generates a -like magnetic field and a magnetic sensor that detects magnetic flux are used to generate an empty space.
! ! Distance movement was detected, but it is not particularly limited.
The air gap distance ill may be configured to be detected using light.

(Effects of the Invention) As shown below, according to the rotation angle detection device using the position 1jt detection sensor of the present invention, it is easy to adjust the gap +JE; m+ when installing the position 15 detection sensor and the rotating disk. At the same time, the reliability of the output signal from the position detection sensor is improved, making it possible to detect the rotation angle with high precision.

[Brief explanation of the drawing]

Figures 1 and (B) are a front view and a plan view showing an example of a rotation angle detection device using the (D and M detection sensors) of the present invention, and Figure 2 is a drive control circuit that drives and controls the main parts thereof. A block diagram showing an example, FIGS. 3 (8) and (B) are a front view and a plan view showing an example of a rotation angle detection device using a conventional position detection sensor, and FIGS. 4 (A) and (B) FIG. 5 is a front view and a plan view showing another example of a rotation angle detection device using a conventional position detection sensor. FIGS. 1... Rotating glaze, 2.▽12.▽22... Rotating disk,
3,13゜2:la, 23b...&J1 air sensor 2▽4...electrostrictive element, 5...magnetic sensor support, 6
...Magnetic bias circuit, 7...Magnetic sensor mounting part,
31...Reference 8 call generator, 32...Subtractor, 3
3...Amplifier. Applicant's agent Yasugata Yu A certain Ko ↑ 6 times the angle sheep 6 illustrations■

Claims (1)

[Claims] 1. In a rotation angle detection device comprising a rotating disk and a position detecting means disposed near the rotating disk and detecting a rotation angle of the rotating disk, an air gap distance between the rotating disk and the position detecting means and a fine movement means for slightly moving the position detection means in a direction to change the gap distance based on a detection signal from the detection means, and a drive control circuit thereof. Angle detection device.