JP2021025851A - Rotation sensor - Google Patents

Abstract

To provide a rotation sensor capable of achieving redundancy without increasing an axial directional size of a rotation shaft.SOLUTION: A first detection unit 130 constitutes an inductive sensor outputting a first rotation signal by detecting, by a flat coil 131, a magnetic change in an axial direction of a rotation shaft 200 caused by change of rotational position of a plate section 110. A second detection unit 140 constitutes a magnetic sensor outputting a second rotation signal by detecting, by a magneto resistive element 142, a magnetic change in a perpendicular direction perpendicular to the axial direction of the rotation shaft 200 caused by rotation of a magnet 141 together with the rotation shaft 200. The plate section 110 functions as a detection target pointing the rotational direction of the plate section 110 in the inductive sensor and also functions as a magnetic shield plate in the magnetic sensor. The first detection unit 130 is arranged in a range of the second detection unit 140 in the axial direction of the rotation shaft 200.SELECTED DRAWING: Figure 1

Description

The present invention relates to a rotation sensor.

Conventionally, a rotation detector that detects the rotation of a rotating shaft has been proposed, for example, in Patent Document 1. The rotation detector includes two detectors. The two detectors have the same configuration as the rotating shaft penetrates.

The two detection units are arranged at regular intervals in the axial direction of the rotation axis. The two detectors are housed in a common housing. Then, the two detection units output the same rotation signal. In this way, the rotation detector is made redundant.

JP-A-2018-109569

However, in the above-mentioned conventional technique, since the two detection units are arranged in the axial direction of the rotation axis, a housing having a size capable of accommodating the two detection units is required. Therefore, the size of the rotation detector in the axial direction with respect to the rotation axis becomes large.

In view of the above points, it is an object of the present invention to provide a rotation sensor capable of achieving redundancy without increasing the size of the rotation axis in the axial direction.

In order to achieve the above object, in the invention according to claim 1, the rotation sensor includes a plate unit (110), a first detection unit (130), and a second detection unit (140).

The plate portion has one surface (113, 116) and a through hole (114, 117) through which one surface is penetrated in a direction perpendicular to one surface and a rotation axis (200) is passed through. The plate portion rotates with the rotation axis.

The first detection unit is arranged so as to face one surface of the plate unit and the position is fixed. The first detection unit detects a magnetic change in the axial direction of the rotation shaft received from one surface of the plate portion as the rotation position of the plate portion changes due to the rotation of the rotation shaft. As a result, the first detection unit outputs the first rotation signal according to the rotation angle of the rotation shaft.

The second detection unit is arranged on the outer circumference of the rotation shaft and the position is fixed. The second detection unit changes the rotation position of the plate unit due to the rotation of the rotation axis, and the magnetic change in the vertical direction perpendicular to the axial direction of the rotation axis based on a detection method different from that of the first detection unit. Is detected. As a result, the second detection unit outputs a second rotation signal according to the rotation angle of the rotation shaft. Then, the first detection unit is arranged within the range of the second detection unit in the axial direction of the rotation axis.

According to this, the first detection unit determines the size in the axial direction in order to detect the magnetic change in the axial direction of the rotation axis. The second detection unit determines the size in the vertical direction in order to detect a magnetic change in the vertical direction perpendicular to the axial direction of the rotation axis. Then, the plate portion is also used when detecting each detection unit. Therefore, it is possible to arrange the first detection unit within the range of the second detection unit in which the size of the rotation axis in the axial direction is fixed. Therefore, the rotation sensor can be made redundant without increasing the size of the rotation axis in the axial direction.

The reference numerals in parentheses of each means described in this column and the scope of claims indicate the correspondence with the specific means described in the embodiments described later.

It is a transmission plan view of the rotation sensor which concerns on 1st Embodiment. FIG. 2 is a sectional view taken along line II-II of FIG. It is a transmission plan view of the rotation sensor which concerns on 2nd Embodiment. FIG. 3 is a sectional view taken along line IV-IV of FIG.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In each of the following embodiments, the same or equal parts are designated by the same reference numerals in the drawings.

(First Embodiment)
Hereinafter, the first embodiment will be described with reference to the drawings. The rotation sensor according to the present embodiment detects, for example, the electric angle of a shaft used for driving a vector control of a motor. The motor is, for example, one mounted on an automobile.

As shown in FIGS. 1 and 2, the rotation sensor 100 is provided on the rotation shaft 200. The rotating shaft 200 is a shaft of a motor. The rotation sensor 100 includes a plate unit 110, a printed circuit board 120, a first detection unit 130, and a second detection unit 140.

The plate portion 110 has a flat surface portion 111 and a tubular portion 112. The flat surface portion 111 is a disk-shaped portion having one surface 113. One surface 113 of the flat surface portion 111 corresponds to one surface 113 of the plate portion 110. The flat surface portion 111 has a through hole 114. The through hole 114 is a portion that penetrates the flat surface portion 111 in a direction perpendicular to the one surface 113. The central position of the through hole 114 corresponds to the position of the central axis of the rotating shaft 200. The tubular portion 112 is a cylindrical portion integrated with the flat surface portion 111 so that the hollow portion communicates with the through hole 114. The diameter of the through hole 114 and the inner diameter of the tubular portion 112 are the same.

The plate portion 110 is formed of a magnetic material such as an electromagnetic steel plate that can obtain a magnetic shielding effect. The plate portion 110 is formed by, for example, pressing one electromagnetic steel plate. Then, the plate portion 110 is fixed to the rotating shaft 200 by press-fitting the rotating shaft 200 into the through hole 114. Therefore, the plate portion 110 rotates around the central axis of the rotating shaft 200 together with the rotating shaft 200. Since it is sufficient that the magnetic shielding effect can be obtained, at least the flat surface portion 111 may be formed of a magnetic material.

Further, the flat surface portion 111 has a recess 115 whose outer edge portion is recessed in a rectangular shape on the through hole 114 side. The recess 115 has a width of a rotation angle of 45 ° about the center of the through hole 114, that is, the central axis of the rotation shaft 200. The recesses 115 are provided at four positions at equal intervals on the outer edge portion of the flat surface portion 111. When the rotating shaft 200 rotates 1/4, the electric angle of 1/4 rotation of the rotating shaft 200 becomes 360 ° because one outer edge portion of the flat surface portion 111 and one recess 115 pass through. It can be said that the electric angle is an angle corresponding to one rotation range of the rotation range in which one rotation of the rotation shaft 200 is equally divided into a plurality of parts.

The printed circuit board 120 is a semi-disc-shaped component having a front surface 121 and a back surface 122. The surface 121 of the printed circuit board 120 is arranged so as to face one surface 113 of the plate portion 110. Wiring and electronic components related to the first detection unit 130 and the second detection unit 140 are mounted on the front surface 121 and the back surface 122 of the printed circuit board 120.

The first detection unit 130 outputs a first rotation signal by detecting a magnetic change in the axial direction of the rotation shaft 200 accompanying a change in the rotation position of the plate unit 110. The first detection unit 130 has a flat coil 131 and a first processing unit 132.

The flat coil 131 is a coil for detecting a magnetic change in the axial direction of the rotating shaft 200. The flat coil 131 is formed on the surface 121 of the printed circuit board 120. That is, the flat coil 131 is formed on a surface perpendicular to the axial direction of the rotating shaft 200. Therefore, the flat coil 131 is arranged so as to face one surface 113 of the plate portion 110, and the position is fixed. The flat coil 131 is arranged, for example, in a shape showing a sine wave. The shape of the sine wave curve is adjusted so that it becomes 360 ° at 1/4 rotation of the rotation axis 200.

The first processing unit 132 is a signal processing circuit having a function of acquiring a change in the inductance of the flat coil 131 and a function of generating a first rotation signal based on the change in the inductance. The first processing unit 132 is configured as, for example, an ASIC (Application Specific Integrated Circuit). The first processing unit 132 is mounted on the back surface 122 of the printed circuit board 120.

The second detection unit 140 detects a magnetic change in the vertical direction perpendicular to the axial direction of the rotating shaft 200 based on a detection method different from that of the first detection unit 130. The second detection unit 140 outputs a second rotation signal by detecting a magnetic change in the vertical direction perpendicular to the axial direction of the rotation shaft 200 accompanying the rotation of the rotation shaft 200. The second detection unit 140 includes a magnet 141, a magnetoresistive element 142, a second processing unit 143, and a magnetic shield plate 144.

The magnet 141 is a cylindrical component that circularly surrounds the rotating shaft 200. The magnet 141 is fixed to the tubular portion 112 by press-fitting the tubular portion 112 of the plate portion 110 into the hollow portion. Therefore, the magnet 141 rotates together with the rotation shaft 200. The magnet 141 has a first magnetic pole 145 that generates an N-pole magnetic force and a second magnetic pole 146 that generates an S-pole magnetic force. A plurality of magnetic poles 145 and 146 are alternately arranged in the circumferential direction about the central axis of the rotating shaft 200.

In this embodiment, the total of the magnetic poles 145 and 146 is 8 poles. When the rotating shaft 200 rotates 1/4, the pair of magnetic poles 145 and 146, that is, one cycle is reached, so that the electric angle of 1/4 rotation of the rotating shaft 200 becomes 360 °.

The magnetoresistive element 142 is configured as one chip. The magnetoresistive element 142 is mounted on the surface 121 of the printed circuit board 120. The magnetoresistive element 142 is arranged with a predetermined gap with respect to the outer peripheral surface 147 of the magnet 141. That is, the magnetoresistive element 142 is arranged on the outer circumference of the rotating shaft 200, and the position is fixed. The magnetoresistive element 142 is arranged to face the central portion of the flat surface portion 111 of the plate portion 110 where the recess 115 is not formed.

The magnetoresistive element 142 detects a change in the magnetic field based on a detection method different from that of the first detection unit 130. Different detection methods have the same meaning as different detection principles. The magnetoresistive element 142 includes an element whose resistance value changes depending on the magnetic field received from the magnet 141. The magnetoresistive element 142 is, for example, an AMR (Anisotropic Magneto Resistance), a GMR (Giant Magneto Resistance), or a TMR (Tunneling Magneto Resistance). Since the cycle of the output waveform of the AMR element is double that of other elements, it is necessary to adjust the number of poles of the magnet 141 to 1/2, but the point of detecting magnetism is the same as that of other elements. Is.

The magnetic resistance element 142 detects a change in the magnetic field due to a change in the rotation position of the rotation shaft 200 due to the rotation of the rotation shaft 200, thereby detecting a sine wave signal and a chord wave according to the electric angle of rotation of the rotation shaft 200. Output a signal. Therefore, the magnetoresistive element 142 includes a half-bridge circuit that outputs a sine wave signal and a half-bridge circuit that outputs a cosine wave signal. The sine wave signal is a sin signal and the cosine wave signal is a cos signal. The sin signal and the cos signal are 90 ° out of phase.

The second processing unit 143 is a signal processing circuit having a function of supplying power to the magnetoresistive element 142, a function of acquiring a magnetic signal from the magnetoresistive element 142, and a function of generating a second rotation signal based on the magnetic signal. Is. The second processing unit 143 is configured as, for example, an ASIC. The second processing unit 143 is mounted on the back surface 122 of the printed circuit board 120.

The magnetic shield plate 144 is a component for shielding a disturbance magnetic field. The magnetic shield plate 144 is formed of a magnetic material such as an electromagnetic steel plate. The magnetic shield plate 144 is arranged so as to face the back surface 122 of the printed circuit board 120, and the position is fixed. As a result, the magnetic shield plate 144 shields the disturbance magnetic field on the back surface 122 side of the printed circuit board 120.

The magnetic shield plate 144 is formed in a disk shape, for example. The magnetic shield plate 144 is, for example, a combination of two semicircular plate-shaped portions. One semi-disc-shaped portion has an arc-shaped recess for preventing contact with the magnet 141. The magnetic shield plate 144 may have a size that covers at least the entire magnetoresistive element 142.

The above is the configuration of the rotation sensor 100 according to the present embodiment. In the above configuration, the plate unit 110, the printed circuit board 120, the flat coil 131, and the first processing unit 132 form an inductive sensor. Further, the plate portion 110, the printed circuit board 120, the magnet 141, the magnetoresistive element 142, the second processing portion 143, and the magnetic shield plate 144 constitute the magnetic sensor. The plate portion 110 is a component common to two sensors having different detection principles.

Then, the plate portion 110 functions as a detection target indicating the rotation position of the plate portion 110 in the inductive sensor, and also functions as a magnetic shield plate for shielding the disturbance magnetic field in the magnetic sensor. The plate portion 110 as the magnetic shield plate shields the disturbance magnetic field on the surface 121 side of the printed circuit board 120. The printed circuit board 120 is also used as an inductive sensor and a magnetic sensor.

In addition, each of the above configurations is housed in a case (not shown). Here, the first detection unit 130 constituting the inductive sensor is arranged within the range of the second detection unit 140 constituting the magnetic sensor in the axial direction of the rotating shaft 200. That is, the plate portion 110 and the flat coil 131 of the inductive sensor are arranged between the plate portion 110 that functions as the magnetic shield plate of the magnetic sensor and the magnetic shield plate 144. Therefore, the overall size of the rotation sensor 100 can be the size of the magnetic sensor.

Next, the operation of the rotation sensor 100 will be described. First, the first processing unit 132 that constitutes the inductive sensor passes a current through the flat coil 131. Then, the flat coil 131 detects a magnetic change in the axial direction of the rotating shaft 200 received from one surface 113 of the plate portion 110 as the rotational position of the plate portion 110 changes due to the rotation of the rotating shaft 200.

Specifically, as the flat surface portion 111 of the plate portion 110 rotates, the outer edge portion of the flat surface portion 111 crosses the flat coil 131 having a shape showing a sine wave. As a result, the magnetic field received by the flat coil 131 from the flat portion 111 changes, so that the inductance changes due to mutual induction. Therefore, the first processing unit 132 acquires the change in inductance as an electric signal. That is, the first processing unit 132 generates a first rotation signal having an electric angle of 360 ° at 1/4 rotation of the rotation shaft 200.

On the other hand, the magnetoresistive element 142 constituting the magnetic sensor moves in the axial direction of the rotating shaft 200 based on a detection method different from that of the inductive sensor as the rotational position of the plate portion 110 changes due to the rotation of the rotating shaft 200. Detects vertical magnetic changes in the vertical direction. The inductive sensor detects the change in inductance based on the magnetic change in the axial direction of the rotating shaft 200, but the magnetoresistive element 142 determines the resistance value based on the magnetic change in the vertical direction perpendicular to the axial direction of the rotating shaft 200. Detect changes.

Specifically, the resistance value of the magnetoresistive element 142 changes according to the change in the magnetic field received from the outer peripheral surface 147 of the magnet 141 as the magnet 141 rotates. As a result, the magnetoresistive element 142 outputs a sine wave signal and a chord wave signal according to the change in the resistance value. Therefore, the second processing unit 143 acquires the sine wave signal and the cosine wave signal, and calculates Arctan θ from each signal. As a result, the second processing unit 143 generates a second rotation signal having an electric angle of 360 ° at 1/4 rotation of the rotation shaft 200.

The first rotation signal and the second rotation signal are, for example, components that increase from 0 at a constant rate of increase, and are voltage components or current components. Here, although the detection principles and detection directions are different, the detection units 130 and 140 are the same in that they acquire a rotation signal whose electric angle becomes 360 ° at 1/4 rotation of the rotation shaft 200. However, the phase and rate of increase of each rotation signal are not the same.

Therefore, each of the processing units 132 and 143 performs signal processing so that the phase shift of each rotation signal becomes 0 and the increase rate of each rotation signal becomes the same. In the present embodiment, the first processing unit 132 inputs the second rotation signal. Then, the first processing unit 132 performs signal processing that matches the phase of the first rotation signal and the rate of increase of the signal with the second rotation signal. As a result, the phases of the first rotation signal output from the first processing unit 132 and the second rotation signal output from the second processing unit 143 become in phase, and the rate of increase of each rotation signal becomes the same. Become. Therefore, the processing units 132 and 143 output exactly the same rotation signal to the outside.

The second processing unit 143 may input the first rotation signal. In this case, the second processing unit 143 performs signal processing that matches the phase of the second rotation signal and the rate of increase of the signal with the first rotation signal. On the other hand, parameters for matching the phase and the rate of increase of the signal may be acquired in advance by monitoring each rotation signal at the manufacturing stage of the rotation sensor 100. In this case, the parameters acquired in advance at the time of manufacturing the rotation sensor 100 are set in the processing units 132 and 143. As a result, the processing units 132 and 143 independently perform signal processing, but output exactly the same rotation signal to the outside.

As described above, the first detection unit 130 constituting the inductive sensor determines the size in the axial direction in order to detect the magnetic change in the axial direction of the rotating shaft 200. On the other hand, the second detection unit 140 constituting the magnetic sensor is sized in the vertical direction in order to detect a magnetic change in the vertical direction perpendicular to the axial direction of the rotating shaft 200. The plate portion 110 is also used when detecting the detection units 130 and 140. By satisfying such a configuration, it is possible to arrange the first detection unit 130 within the range of the second detection unit 140 in which the size of the rotating shaft 200 in the axial direction is determined. Therefore, the rotation sensor 100 can be made redundant without increasing the size of the rotation sensor 100 in the axial direction of the rotation shaft 200.

Further, the detection principles and detection directions of the detection units 130 and 140 are different. Therefore, the variety of the rotation sensor 100 can be increased. That is, although the rotation sensor 100 secures redundancy by the two detection units 130 and 140, the possibility of dependent failure due to the same cause can be reduced due to the diversity of the sensors.

Regarding the correspondence between the description of the present embodiment and the description of the claims, the first processing unit 132 and the second processing unit 143 correspond to the "adjustment unit" of the claims.

As a modification, each processing unit 132, 143 may output each rotation signal as a signal that vibrates at a constant cycle, such as a sine wave signal or a cosine wave signal. In this case, the processing units 132 and 143 adjust the phase shift of each rotation signal and perform signal processing so that the amplitudes of the signals are the same.

As a modification, the second detection unit 140 may have a plurality of magnetic resistance elements 142. The plurality of magnetoresistive elements 142 are arranged at equal intervals on the outer circumference of the magnet 141. The second processing unit 143 adds or subtracts the signal of each magnetoresistive element 142 according to a predetermined calculation formula. As a result, higher-order components contained in the sine wave signal and the cosine wave signal can be canceled out.

(Second Embodiment)
In this embodiment, a part different from the first embodiment will be mainly described. As shown in FIGS. 3 and 4, the rotation sensor 100 includes a plate unit 110, a printed circuit board 120, a first detection unit 130, and a second detection unit 140.

The plate portion 110 is a plate-shaped part having one side 116. The plate portion 110 has a through hole 117 penetrating in a direction perpendicular to one surface 116. The central position of the through hole 117 corresponds to the position of the central axis of the rotating shaft 200. The plate portion 110 is configured as a laminated body of a plurality of magnetic plates. The plate portion 110 may be composed of one plate. The plate portion 110 is fixed to the rotating shaft 200 by press-fitting the rotating shaft 200 into the through hole 117. One side 116 of the plate portion 110 is arranged to face the surface 121 of the printed circuit board 120.

Further, the plate portion 110 has a recess 118 whose outer edge portion is recessed in an arc shape on the through hole 117 side. The recesses 118 are provided at 90 ° intervals about the center of the through hole 117, that is, the central axis of the rotating shaft 200. The recesses 118 are provided at four positions at equal intervals on the outer edge portion of the plate portion 110. In other words, the outer edge portion of the plate portion 110 projects at four positions at equal intervals in the circumferential direction of the rotating shaft 200. This corresponds to the 8-pole resolver described later.

Further, the outer peripheral shape of one side 116 of the plate portion 110 is a shape showing a sine wave. The shape of the sine wave curve is adjusted so that it becomes 360 ° at 1/4 rotation of the rotation axis 200. When the rotating shaft 200 rotates 1/4, the curve of one sine wave passes through, so that the electric angle of 1/4 rotation of the rotating shaft 200 becomes 360 °.

The first detection unit 130 constitutes an inductive sensor. In the present embodiment, the first detection unit 130 has a flat coil 133 and a first processing unit 132.

The flat coil 133 is a coil for detecting a magnetic change in the axial direction of the rotating shaft 200. The flat coil 133 is wound in a quadrangular shape, for example. The flat coil 133 is formed at two locations on the surface 121 of the printed circuit board 120. The two planar coils 133 are arranged with a rotation angle of 45 ° about the central axis of the rotation shaft 200. One planar coil 133 is a coil for acquiring a sine wave signal, and the other planar coil 133 is a coil for acquiring a cosine wave signal.

The first processing unit 132 has a function of acquiring a change in the inductance of the plane coil 133, a function of acquiring a sine wave signal and a chord wave signal based on the change in inductance, and a first processing unit 132 based on the sine wave signal and the chord wave signal. It has a function of generating a one-turn signal. The first processing unit 132 generates a first rotation signal that increases from 0 at a constant rate of increase by calculating Arctan θ from the sine wave signal and the cosine wave signal.

The second detection unit 140 outputs a second rotation signal by detecting a magnetic change in the vertical direction perpendicular to the axial direction of the rotation shaft 200 accompanying the rotation of the plate portion 110 together with the rotation shaft 200. The second detection unit 140 includes a stator core 148, a detection coil 149, and a second processing unit 143.

The stator core 148 is an annular component that surrounds the outer circumference of the plate portion 110. The stator core 148 has a plurality of salient poles 150 on the inner peripheral portion. Each salient pole 150 projects toward the plate portion 110. The plurality of salient poles 150 are provided at intervals of 45 ° about the central axis of the rotating shaft 200. That is, eight salient poles 150 are provided on the stator core 148.

The detection coil 149 is wound around each salient pole 150. The detection coil 149 acquires, as a voltage signal, a change in the magnetic field received from the outer peripheral portion of the plate portion 110 as the outer peripheral surface 119 of the plate portion 110 approaches or moves away with the rotation of the rotating shaft 200. The detection coil 149 includes, for example, a primary coil for acquiring a sine wave signal and a secondary coil for acquiring a cosine wave signal. The detection coil 149 may have a configuration capable of acquiring a sine wave signal and a cosine wave signal.

The second processing unit 143 has a function of acquiring a sine wave signal and a chord wave signal from the detection coil 149, and a function of generating a second rotation signal based on the sine wave signal and the chord wave signal. The second processing unit 143 generates a second rotation signal that increases from 0 at a constant rate of increase by calculating Arctan θ from the sinusoidal wave signal and the cosine wave signal.

The above is the configuration of the rotation sensor 100 according to the present embodiment. In the above configuration, the plate unit 110, the printed circuit board 120, the flat coil 133, and the first processing unit 132 constitute an inductive sensor. Further, the plate portion 110, the printed circuit board 120, the stator core 148, the detection coil 149, and the second processing portion 143 form a resolver.

Then, the plate portion 110 functions as a detection target indicating the rotation position of the plate portion 110 in both the inductive sensor and the resolver. As described above, the plate portion 110 is a component common to two sensors having different detection principles. The printed circuit board 120 is also used as an inductive sensor and a resolver.

In addition, each of the above configurations is housed in a case (not shown). Here, the first detection unit 130 constituting the inductive sensor is arranged within the range of the second detection unit 140 constituting the resolver in the axial direction of the rotating shaft 200. That is, the plate portion 110 and the flat coil 133 of the inductive sensor are arranged within the thickness range of the stator core 148 of the resolver in the axial direction of the rotating shaft 200. Therefore, the overall size of the rotation sensor 100 can be the size of the resolver.

Next, the operation of the rotation sensor 100 will be described. First, the first processing unit 132 that constitutes the inductive sensor passes a current through the flat coil 133. Then, the flat coil 133 detects the magnetic change in the axial direction of the rotating shaft 200 received from one surface 116 of the plate portion 110 as the rotational position of the plate portion 110 changes due to the rotation of the rotating shaft 200.

Specifically, as the rotation shaft 200 rotates, the outer edge portion of the plate portion 110 having a shape showing a sine wave crosses the two flat coils 133. As a result, the inductances of the two planar coils 133 change due to mutual induction, and the first processing unit 132 acquires the changes in inductance as a sine wave signal and a chord wave signal. The first processing unit 132 calculates Arctan θ from each signal to generate a first rotation signal having an electric angle of 360 ° at 1/4 rotation of the rotation axis 200.

On the other hand, the detection coil 149 constituting the resolver is perpendicular to the axial direction of the rotating shaft 200 based on a detection method different from that of the inductive sensor as the rotational position of the plate portion 110 changes due to the rotation of the rotating shaft 200. Detects vertical magnetic changes.

Specifically, the induced current of the detection coil 149 changes according to the change of the magnetic field received from the outer peripheral surface 119 of the plate portion 110 with the rotation of the rotating shaft 200. As a result, the induced current flowing through the detection coil 149 changes, so that the second processing unit 143 acquires the change in the induced current as a sine wave signal and a chord wave signal. The second processing unit 143 calculates Arctan θ from each signal to generate a second rotation signal having an electric angle of 360 ° at 1/4 rotation of the rotation shaft 200.

Further, each of the processing units 132 and 143 performs signal processing so that the phase shift of each rotation signal becomes 0 and the increase rate of each rotation signal becomes the same, as in the first embodiment. Therefore, the processing units 132 and 143 output exactly the same rotation signal to the outside.

As described above, the plate portion 110 is also used as a detection target for each sensor. Further, the first detection unit 130 constituting the inductive sensor is arranged within the range of the second detection unit 140 constituting the resolver in the axial direction of the rotating shaft 200. Therefore, the same effect as that of the first embodiment can be obtained.

(Other embodiments)
The configuration of the rotation sensor 100 shown in each of the above embodiments is an example, and the configuration is not limited to the configuration shown above, and other configurations capable of realizing the present invention can be used. For example, the motor is not limited to that mounted on an automobile.

Each processing unit 132, 143 may be configured as one signal processing circuit unit. That is, the rotation sensor 100 may have a signal processing circuit unit common to the first detection unit 130 and the second detection unit 140.

In each of the above embodiments, the setting that the electric angle becomes 360 ° at 1/4 rotation of the rotating shaft 200 is an example. For example, the electric angle may be set to 360 ° at 1/8 rotation of the rotation shaft 200. Of course, the detection units 130 and 140 are configured to detect the electric angles of the same angle.

110 Plate part 113, 116 One side 114, 117 Through hole 130, 140 Detection part 131, 133 Flat coil 141 Magnet 142 Magnetoresistive element 145, 146 Magnetic pole 147 Outer peripheral surface of magnet 149 Detection coil

Claims (4)

A plate having one surface (113, 116) and a through hole (114, 117) through which the one surface is penetrated in a direction perpendicular to the one surface and through which a rotation shaft (200) is passed, and which rotates together with the rotation shaft. Part (110) and
The axis of the rotating shaft received from the one surface of the plate portion as the rotating position of the plate portion changes due to the rotation of the rotating shaft, which is arranged facing the one surface of the plate portion and the position is fixed. A first detection unit (130) that outputs a first rotation signal according to the rotation angle of the rotation axis by detecting a magnetic change in the direction.
The rotation is based on a detection method different from that of the first detection unit as the rotation position of the plate portion changes due to the rotation of the rotation shaft while being arranged on the outer periphery of the rotation shaft and the position is fixed. A second detection unit (140) that outputs a second rotation signal according to the rotation angle of the rotation axis by detecting a magnetic change in the vertical direction perpendicular to the axis direction.
Including
The first detection unit is a rotation sensor arranged within the range of the second detection unit in the axial direction of the rotation shaft. The first detection unit has a planar coil (131) formed on a plane perpendicular to the axial direction of the rotation shaft, and the axial direction of the rotation shaft is accompanied by a change in the rotation position of the plate portion. An inductive sensor that outputs the first rotation signal by detecting the magnetic change of the above by the plane coil is configured.
The second detection unit is a cylinder in which a first magnetic pole (145) that surrounds the rotation axis in an annular shape and generates an N-pole magnetic force and a second magnetic pole (146) that generates an S-pole magnetic force are alternately arranged. It has a magnet (141) and a magnetic resistance element (142) that is arranged to face the outer peripheral surface (147) of the magnet and whose resistance value changes depending on the magnetic field received from the magnet. A magnetic sensor that outputs the second rotation signal is configured by detecting the magnetic change in the vertical direction perpendicular to the axial direction of the rotation axis accompanying the rotation of the magnet by the magnetic resistance element.
The rotation sensor according to claim 1, wherein the plate portion functions as a detection target indicating the rotation position of the plate portion in the inductive sensor and also functions as a magnetic shield plate in the magnetic sensor. The first detection unit has a planar coil (133) formed on a plane perpendicular to the axial direction of the rotation shaft, and the axial direction of the rotation shaft is accompanied by a change in the rotation position of the plate portion. An inductive sensor that outputs the first rotation signal by detecting the magnetic change of the above by the plane coil is configured.
The second detection unit has a plurality of detection coils (149) arranged on the outer periphery of the plate portion, and is perpendicular to the axial direction of the rotation shaft as the plate portion rotates together with the rotation shaft. A resolver that outputs the second rotation signal by detecting the magnetic change in the vertical direction by the detection coil is configured.
The rotation sensor according to claim 1, wherein the plate portion functions as a detection target indicating the rotation position of the plate portion in both the inductive sensor and the resolver. An adjusting unit that performs signal processing of either or both of the first rotation signal and the second rotation signal so that the phase of the first rotation signal and the phase of the second rotation signal become zero. The rotation sensor according to any one of claims 1 to 3 including 132, 143).

Images