WO2007055135A1 - Magnetic encoder device - Google Patents

Magnetic encoder device Download PDF

Info

Publication number
WO2007055135A1
WO2007055135A1 PCT/JP2006/321870 JP2006321870W WO2007055135A1 WO 2007055135 A1 WO2007055135 A1 WO 2007055135A1 JP 2006321870 W JP2006321870 W JP 2006321870W WO 2007055135 A1 WO2007055135 A1 WO 2007055135A1
Authority
WO
WIPO (PCT)
Prior art keywords
magnetic field
field detection
permanent magnet
magnetic
detection element
Prior art date
Application number
PCT/JP2006/321870
Other languages
French (fr)
Japanese (ja)
Inventor
Takefumi Kabashima
Ikuma Murokita
Katsumasa Yoshida
Yasushi Yoshida
Original Assignee
Kabushiki Kaisha Yaskawa Denki
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Kabushiki Kaisha Yaskawa Denki filed Critical Kabushiki Kaisha Yaskawa Denki
Priority to JP2007544107A priority Critical patent/JPWO2007055135A1/en
Publication of WO2007055135A1 publication Critical patent/WO2007055135A1/en

Links

Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01D—MEASURING NOT SPECIALLY ADAPTED FOR A SPECIFIC VARIABLE; ARRANGEMENTS FOR MEASURING TWO OR MORE VARIABLES NOT COVERED IN A SINGLE OTHER SUBCLASS; TARIFF METERING APPARATUS; MEASURING OR TESTING NOT OTHERWISE PROVIDED FOR
    • G01D5/00—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable
    • G01D5/12—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable using electric or magnetic means
    • G01D5/14—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable using electric or magnetic means influencing the magnitude of a current or voltage
    • G01D5/142—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable using electric or magnetic means influencing the magnitude of a current or voltage using Hall-effect devices
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01D—MEASURING NOT SPECIALLY ADAPTED FOR A SPECIFIC VARIABLE; ARRANGEMENTS FOR MEASURING TWO OR MORE VARIABLES NOT COVERED IN A SINGLE OTHER SUBCLASS; TARIFF METERING APPARATUS; MEASURING OR TESTING NOT OTHERWISE PROVIDED FOR
    • G01D2205/00—Indexing scheme relating to details of means for transferring or converting the output of a sensing member
    • G01D2205/80—Manufacturing details of magnetic targets for magnetic encoders

Definitions

  • the present invention relates to a magnetic encoder device that detects a rotational position of a rotating body.
  • FIG. 22 is a perspective view showing the configuration of the magnetic encoder in the first prior art.
  • 1 is a rotating body
  • 2 is a permanent magnet fixed to the rotating body 1 via a rotating shaft 11, and is magnetized in one direction perpendicular to the rotating shaft 11.
  • Reference numerals 611 to 614 denote magnetic field detection elements, which are arranged on the permanent magnet 2 via a gap in the axial direction and fixed on the fixed body 7.
  • the magnetic field detection elements 611 to 614 are arranged in the circumferential direction with a mechanical angle shifted by 90 degrees from each other, and detect a change in the magnetic field generated by the permanent magnet 2 according to the rotation of the rotating body 1. This detection signal is converted into a rotation angle by the signal processing circuit 5, and the absolute value position of the rotating body 1 is detected.
  • a magnetic field generated by a permanent magnet magnetized in parallel with two poles in a plane attached to the rotating body is detected by six magnetic field detecting elements arranged at equal intervals in the axial direction via gaps.
  • a device that detects the absolute value of the position of a rotating body is disclosed (for example, see Patent Document 2).
  • FIG. 23 is a perspective view showing a configuration of a magnetic encoder in the second prior art.
  • 1 is a rotating body
  • 2 is a permanent magnet fixed to the rotating body 1 via a rotating shaft 11.
  • the rotating shaft 11 is magnetized in one direction perpendicularly.
  • a pair of A1 phase detection elements 621 and A2 phase detection elements 622, B1 Phase detection element 623 and B2 phase detection element 624, and C1 phase detection element 625 and C2 phase detection element 626, consisting of a total of three pairs, are arranged on fixed body 7.
  • FIG. 24 is a block diagram of a signal processing circuit.
  • the signal processing circuit includes a first detector for A1 phase detector 621 and A2 detector 622, B1 detector 623 and B2 detector 624, and C1 detector 625 and C2 detector 626, respectively.
  • Differential amplifiers 81, 82, and 83 are provided.
  • the first differential amplifiers 81 to 83 remove even-order harmonic components by taking the difference between the output signals of the pair of magnetic field detection elements.
  • second differential amplifiers 84 and 85 are provided at the subsequent stage of the first differential amplifiers 81 and 82 and the first differential amplifiers 82 and 83, respectively.
  • the second differential amplifiers 84 and 85 combine two differential output signals after removing even-order harmonic components by the first differential amplifiers 81 and 82 and the first differential amplifiers 82 and 83, respectively. By taking the sum, the third-order harmonic component contained in the differential output signal was removed, and the encoder was highly accurate.
  • an N pole is formed at one end of the circumference of the disk-shaped permanent magnet fixed to the rotating shaft, and an S pole is formed at the other end, with a fixed gap and a magnetoresistive element on the axis.
  • An angle sensor in which the above is arranged is disclosed (for example, see Patent Document 3).
  • FIG. 25 is a perspective view of the angle sensor in the third conventional example
  • FIG. 26 is a graph showing the relationship between the rotation angle of the angle sensor and the output voltage.
  • a magnet is mounted on the rotating shaft of the rotating body, and a magnetic sensor having a plurality of magnetoresistive elements arranged in different detection directions is installed perpendicular to the direction in which the magnet rotates to detect the rotation of the object.
  • a rotation detector is disclosed (for example, see Patent Document 4).
  • FIG. 27 is a perspective view showing a configuration of a rotation detector in the fourth prior art.
  • 22 is a cylindrical outer shape, and a permanent magnet with two poles, N pole and S pole, on the top surface.
  • the magnetic sensor 37 detects the rotation of the magnetic field and outputs a signal of one waveform per rotation.
  • the rotation of the rotating body is detected from the change in output.
  • the direction of rotation can also be detected.
  • Patent Document 1 Japanese Unexamined Patent Publication No. 2000-65596
  • Patent Document 2 JP 2001-33277 A
  • Patent Document 3 Japanese Patent Publication No. 7-119619
  • Patent Document 4 Japanese Patent Laid-Open No. 7-27776
  • the magnetic field generated by the permanent magnet attached to the rotating body is a sine wave with a small distortion, so that a highly accurate encoder can be obtained.
  • the number of power lines and output signal lines for driving the magnetic field detection elements increases. Therefore, there is a problem that the installation of wiring and magnetic field detection elements becomes complicated and the cost increases.
  • it is necessary to install the magnetic field detection elements at equal intervals but there is a problem that the installation accuracy greatly affects the encoder accuracy.
  • since there are many wires noise is easily picked up and reliability is low!
  • the magnetic encoder device disclosed in the second prior art since the magnetic encoder device disclosed in the second prior art has a large size of the magnetic field detection element, it is necessary to install each magnetic field detection element away from the center of the rotation axis. There was a problem that the size becomes large. In addition, since it is difficult to arrange them at regular intervals with high accuracy, the detection accuracy deteriorates due to the eccentricity of the permanent magnet and the shake of the rotating shaft. was there. Furthermore, there was a variation in the characteristics of each magnetic field detection element, and there was a problem that it was not possible to completely remove the second and third order harmonic components.
  • the magnetic field detection element is mounted near the permanent magnet, and the drive circuit and signal amplification circuit that drive the magnetic field detection element are installed away from the permanent magnet, so the number of power lines and output signal lines increases. There was a problem and noise resistance was lowered.
  • the magnetic encoder disclosed in the third prior art is limited to a range in which the angle detection range has linearity of the output voltage, and the force is low in accuracy. Therefore, there was a problem that could not be applied to servo motors that are required to detect the rotation angle with high accuracy over the entire 360 ° range.
  • the rotation detection device disclosed in the fourth prior art can detect a rough position, but cannot be applied to a servo motor or the like that is required to detect a rotation angle with high accuracy. there were.
  • the present invention has been made in view of such problems, and has a simple configuration and can be miniaturized.
  • Another object of the present invention is to provide a highly reliable magnetic encoder device that is low in cost and highly reliable against eccentricity of a permanent magnet and shake of a rotating shaft.
  • the present invention is configured as follows.
  • the invention according to claim 1 is a disk-shaped or ring-shaped permanent magnet fixed to a rotating body and magnetized in two poles, a magnetic field detector for detecting a magnetic field generated by the permanent magnet, and the magnetic And a signal processing circuit for processing a signal from a field detection unit, wherein the magnetic field detection unit detects the absolute position of the rotating body in the direction of the rotation axis of the rotating body.
  • a magnetic field detecting element unit is provided, which is arranged through a magnet and a gap, and detects a magnetic field in a plurality of axial directions in a plane perpendicular to the rotation axis on an extension of a rotation center axis of the permanent magnet.
  • the invention according to claim 2 is characterized in that the plurality of axial directions are biaxial directions.
  • the invention according to claim 3 is characterized in that the plurality of axial directions are three axial directions.
  • the invention described in claim 4 is characterized in that the magnetic field detection element section is formed by forming magnetic field detection elements for detecting magnetic fields in the respective axial directions close to each other by a semiconductor technology.
  • the invention described in claim 5 is characterized in that the magnetic field detection element portion is arranged close to a magnetic field detection element package for detecting a magnetic field in each axial direction.
  • the magnetic field detection unit includes the magnetic field detection element unit, a drive circuit that drives the magnetic field detection element unit, and a signal processing that processes an output signal of the magnetic field detection element unit.
  • the feature is that the parts are integrated in one package.
  • the invention according to claim 7 is characterized in that the permanent magnet is magnetized in parallel in a plane perpendicular to the rotation axis.
  • the invention according to claim 8 is characterized in that the permanent magnet has a permanent magnet force having parallel anisotropy.
  • the magnetic field detection unit includes the magnetic field detection element unit that detects magnetic fields in a plurality of axial directions in a plane perpendicular to the rotation axis, one simple magnetic field detection unit is provided.
  • the rotation angle can be detected with a simple configuration. Therefore, the number of leads can be reduced, and manufacturing and assembly costs can be reduced.
  • the magnetic field detector is arranged on the extension of the rotation center axis of the permanent magnet, the fluctuation of the detected magnetic field due to the eccentricity or shake of the rotation axis is reduced, and a highly accurate encoder can be realized.
  • the permanent magnet has a hollow ring shape, the permanent magnet can be mounted on a rotating shaft to be detected such as a motor. Therefore, the encoder and the detection target can be integrated, the configuration is simple, the vibration resistance is improved, and the size can be reduced.
  • the magnetic field detection unit includes a magnetic field detection element unit that detects a magnetic field in two axial directions in a plane perpendicular to the rotation axis, the size of the magnetic field detection unit Can be reduced
  • the rotation angle can be detected with a simple configuration.
  • the magnetic field detection unit includes a magnetic field detection element unit that detects a magnetic field in three axial directions in a plane perpendicular to the rotation axis
  • the size of the magnetic field detection unit Can be reduced
  • the waveform distortion is canceled out by canceling the harmonic components of the second and third order multiples.
  • V signal can be output.
  • the magnetic field detection elements of the magnetic field detection element portion are formed closer to each other by semiconductor technology, the fluctuation in characteristics between the elements can be reduced and the accuracy can be reduced. A good detection signal is obtained.
  • the magnetic field detection element unit is configured in the vicinity of the magnetic field detection element package, the detection magnetic field variation due to eccentricity or shake of the rotating shaft is small with a simple configuration. A highly accurate encoder can be realized.
  • the magnetic field detection element unit, the drive circuit, and the signal processing unit are provided.
  • the magnetic field detector is configured by integrating in one package, a small size can be realized, the number of leads can be reduced, and manufacturing and assembly costs can be reduced.
  • the angle information can be communicated to the host controller using digital signals, improving noise resistance and lengthening the output signal line.
  • the permanent magnet is magnetized in parallel in a plane perpendicular to the rotation axis, the magnetic field generated by the permanent magnet becomes a sine wave with a small distortion, and a highly accurate error is obtained. Can be provided.
  • the permanent magnet if the permanent magnet has parallel anisotropy, the permanent magnet can be easily magnetized in parallel in the plane without requiring a special magnetizing device. You can do it.
  • FIG. 1 is a perspective view of a magnetic encoder showing a first embodiment of the present invention.
  • FIG. 2 is an enlarged view of a magnetic field detector in the first embodiment of the present invention.
  • FIG. 3 is a block diagram of a signal processing circuit in the first embodiment of the present invention.
  • FIG. 4 is a circuit diagram of a waveform shaping circuit according to the first embodiment of the present invention.
  • FIG. 5 is an output waveform diagram of the magnetic field detector in the first embodiment of the present invention.
  • FIG. 6 is a perspective view of a magnetic encoder showing a second embodiment of the present invention.
  • FIG. 7 is a configuration diagram of a magnetic field detector showing a third embodiment of the present invention.
  • FIG. 8 is a block diagram of a signal processing circuit according to a third embodiment of the present invention.
  • FIG. 9 is a configuration diagram of a magnetic field detector showing a fourth embodiment of the present invention.
  • FIG. 10 is a configuration diagram of a magnetic field detector according to a fifth embodiment of the present invention.
  • FIG. 11 is an enlarged view of a magnetic field detector in a fifth embodiment of the present invention.
  • FIG. 12 is a graph showing changes in the magnetic field of the magnetic field detection element unit in the fifth example of the present invention.
  • FIG. 13 is a graph showing the signal output of the magnetic field detection element portion in the fifth embodiment of the present invention.
  • FIG. 14 is a graph showing the relationship between the detected magnetic flux density of the Hall element and the Hall output voltage.
  • FIG. 15 is a circuit diagram of a sensor signal processing unit in a fifth embodiment of the present invention.
  • FIG. 16 is a graph showing the relationship between the second harmonic component and the amount of eccentricity.
  • FIG. 17 is a graph showing a waveform of an output signal of a differential operation unit in the fifth example of the present invention.
  • FIG. 18 is a graph obtained by performing FFT analysis on the output signal of the differential operation unit in the fifth example of the present invention.
  • FIG. 19 is a graph showing a waveform of an output signal of a three-phase / two-phase converter in the fifth embodiment of the present invention.
  • FIG. 20 is a diagram obtained by FFT analysis of the output signal of the three-phase / two-phase converter in the fifth embodiment of the present invention.
  • FIG. 21 is a block diagram of a signal processing circuit in a fifth example of the present invention.
  • FIG. 22 is a perspective view showing a configuration of a magnetic encoder in the first prior art.
  • FIG. 23 is a perspective view showing a configuration of a magnetic encoder in the second conventional technique.
  • FIG. 24 is a block diagram of a signal processing circuit in the second prior art.
  • FIG. 25 is a perspective view of an angle sensor in a third conventional example.
  • FIG. 26 is a graph showing the relationship between the rotation angle of the angle sensor and the output voltage in the third conventional example.
  • FIG. 27 is a perspective view showing a configuration of a rotation detector in the fourth prior art.
  • Rotation center axis 1 Rotation axis
  • Magnetic field detection element 621 to 626 Magnetic field detection element
  • FIG. 1 is a perspective view of a magnetic encoder showing a first embodiment of the present invention.
  • 1 is a rotating body
  • 2 is a permanent magnet constituting a magnet generator fixed to the rotating body 1 via a rotating shaft 11, and is perpendicular to the rotating shaft 11 as indicated by an arrow in the figure.
  • 3 is a magnetic field detector, and the magnetic field detector 3 is installed on the processing circuit board 4 together with the signal processing circuit 5.
  • the magnetic field detection unit 3 includes a magnetic field detection element unit 31 installed on the rotation center axis 10 of the rotating body 1.
  • the magnetic field detection element unit 31 detects a magnetic field in the biaxial direction on the XY plane perpendicular to the rotation axis 11, and the detection direction of the magnetic field is mutually different by 90 degrees in mechanical angle.
  • a permanent magnet 2 in which a samarium cobalt magnet having a diameter of 10 mm and a thickness of 2 mm was magnetized in parallel in one direction was used.
  • the magnetic field detector 3 was arranged on the rotation center axis 10 through a gap of 2 mm with the permanent magnet 2.
  • two pairs of magnetic field detecting elements are arranged on a concentric circle with respect to the rotational center of the rotating body, and are 90 degrees out of phase with each other in the circumferential direction of the permanent magnet. Two pairs are provided at different positions.
  • the magnetic field detecting element portion for detecting the magnetic field in the biaxial direction is arranged on the rotation center axis.
  • FIG. 2 is an enlarged view of the magnetic field detector in the present embodiment.
  • reference numeral 3 denotes an embodiment of the magnetic field detection unit.
  • the magnetic field detection element unit 31 of the magnetic field detection unit 3 is a magnetic field detection element in which the detection directions of the magnetic field are different from each other by about 90 degrees in the plane.
  • Certain Hall elements 311 and 312 are formed using semiconductor technology. Hall element 311 detects a magnetic field Bx in the X-axis direction, and Hall element 312 detects a magnetic field By in the Y-axis direction.
  • Drive terminal A and drive terminal B are connected to a drive circuit (not shown) of Hall elements 311 and 312, and a drive current is passed through Hall elements 311 and 312.
  • the Hall elements 311 and 312 receive magnetic fields Bx and By corresponding to the rotation angle and output sine wave and cosine wave Hall voltages va and vb from the terminal va and the terminal vb, respectively.
  • the diameter of the magnetic field detecting element 31 is 200 m, and the distance between the Honore elements 311 and 312 is 20 / zm or less. Therefore, when viewed from the permanent magnet 2, the Hall elements 311 and 312 can be regarded as being substantially in the same position.
  • FIG. 3 is a block diagram of the signal processing circuit in the present embodiment.
  • the signal processing circuit 5 calculates an angle of rotation by an amplifier 51 that amplifies the Hall voltage va that is an output signal of the Hall element 311, an amplifier 52 that amplifies the Hall voltage vb of the Hall element 312, and a waveform shaping circuit 53.
  • An angle calculation circuit 54 is provided.
  • the waveform shaping circuit 53 is provided with an amplitude adjustment circuit for making the amplitude the same. Furthermore, an offset compensation circuit that cancels the offset of the output signal and a phase adjustment circuit that makes the phase difference of the output signal exactly 90 degrees in electrical angle are provided.
  • Figure 4 is a circuit diagram of the waveform shaping circuit.
  • 531 and 532 are operational amplifiers constituting an offset compensation circuit
  • 533 and 534 are an adder 533 and subtractor 534 constituting a phase adjustment circuit
  • 535 and 5 36 are phase-adjusted signals.
  • This is an operational amplifier (amplitude adjustment circuit) that adjusts the amplitude of.
  • the outputs VA and VB of the operational amplifiers 535 and 536 are input to the angle calculation circuit 54.
  • the magnetic field detector 3 detects the magnetic flux density of the sine wave and cosine wave according to the rotation angle position, and outputs the Hall voltages va and vb as shown in FIG.
  • the Hall voltages va and vb are amplified by the amplifiers 51 and 52 of the signal processing circuit 5 and then input to the waveform shaping circuit 53.
  • the waveform shaping circuit 53 the offset, phase, and amplitude are adjusted.
  • the two-phase signals Va and Vb amplified by the amplifiers 51 and 52 are offset from the amplifiers 531 and 532 of the waveform shaping circuit shown in FIG. 4 and input to the adder 533 and subtracter 534; the phase difference is 90 The phase is adjusted to a degree. Further, the amplitude of the signals output from the adder 533 and the subtracter 534 is adjusted by the amplifiers 535 and 536. This amplitude adjusted The two-phase output signals VA and VB from the waveform shaping circuit 53 are input to the angle calculation circuit 54, and an angle signal is generated by tangent calculation.
  • the detected magnetic flux density waveform is displaced according to the amount of eccentricity.
  • the output signals of the opposing magnetic field detection elements are differentiated to eliminate the influence of eccentricity.
  • the magnetic field detection element portions for detecting the magnetic fields Bx and By in the two-axis directions are substantially at the same position, the rate of change in the amplitude values of the Hall voltages va and vb due to the influence of eccentricity is the same.
  • the processing functions of the waveform shaping circuit 53 and the angle calculation circuit 54 may be performed by software processing.
  • This encoder was evaluated using an encoder with 1 million rotations per rotation as a reference encoder, but an absolute position signal with extremely high resolution was obtained with 32000 rotations per rotation.
  • a permanent magnet a force using a samarium-cobalt-based magnet whose characteristic change due to temperature is small.
  • the permanent magnet other rare earth magnets, ferrite-based magnets, bonded magnets are used.
  • the same effect can be obtained even if the force magnetoresistive element described in the case where the Hall element is used as the magnetic field detecting element.
  • a method of calculating the absolute angle a method of digital calculation processing of a sine wave and cosine wave force is adopted, but the angle is obtained by a phase tracking method, a multiplication method, a phase modulation method, or the like. Also good.
  • FIG. 6 is a perspective view of a magnetic encoder showing a second embodiment of the present invention.
  • 2 ' is a ring-shaped permanent magnet.
  • a neodymium bonded magnet having an inner diameter of 3 mm, an outer diameter of 10 mm, and a thickness of 2 mm was magnetized in parallel in one direction.
  • the magnetic field detector 3 is a magnetic field installed on the rotation center axis 10 of the rotating body 1.
  • a field detection element unit 31 is provided to detect magnetic fields in the X and Y axes on the XY plane perpendicular to the rotation axis 11.
  • This embodiment differs from the first embodiment in that a ring-shaped permanent magnet is used as the permanent magnet. Since other configurations are the same as those of the first embodiment, the description thereof is omitted.
  • the permanent magnet can be mounted on the rotation shaft to be detected such as a motor. Therefore, the encoder and the detection target can be integrated, the configuration is simple, the vibration resistance is improved, and the size can be reduced.
  • FIG. 7 is a configuration diagram of a magnetic field detector showing a third embodiment of the present invention.
  • 3 shows an embodiment of the magnetic field detector.
  • Reference numerals 321 and 322 denote Hall element packages that detect a magnetic field in one direction.
  • the Hall element package is 2mm square and 0.5mm thick. It has two drive terminals (not shown) that supply drive current to the Hall element package and two output terminals that output Hall voltage.
  • a magnetic field detection element (not shown) having an outer diameter of 50 m is disposed at the center, and is connected to the drive terminal and the signal output terminal and molded with resin.
  • a magnetic field detection element (not shown) of the Hall element package is formed so as to detect a magnetic field parallel to the package surface.
  • the Hall element packages 321 and 322 are arranged on the rotation center axis 10 so that the magnetic field detection directions are approximately 90 degrees with respect to each other via the permanent magnet 3 and the lmm gap. Yes. Since it is difficult to install the two Hall element packages 321 and 322 so that the magnetic field detection direction is exactly 90 degrees in terms of mechanical angle, adjust the waveform shaping circuit so that the phase is 90 degrees.
  • FIG. 8 is a block diagram of a signal processing circuit in the present embodiment.
  • the Hall voltages Va + and Va ⁇ output from the Hall element package 321 and the Hall voltages Vb + and Vb ⁇ output from the Hall element package 322 are differentially input to the amplifiers 51 and 52 of the signal processing circuit 5, respectively. Since the subsequent processing of the waveform shaping circuit 53 and the angle calculation circuit 54 is the same as that of the first embodiment, the description thereof is omitted. As in the first example, this encoder was evaluated using an encoder with 1 million rotations per rotation as a reference encoder, but an absolute position signal with 16000 divisions was obtained.
  • FIG. 9 is a configuration diagram of a magnetic field detector showing a fourth embodiment of the present invention.
  • 3 shows an embodiment of the magnetic field detector.
  • the magnetic field detection element unit 31 in which two Hall elements 311 and 312 are arranged, the Hall element drive circuit 34 for driving the Hall element, and the amplification circuit for the Hall element output signal are integrated in one package.
  • the number of parts was reduced by using one package, the number of assembling steps was reduced, and the cost was reduced.
  • the signal is amplified and output, the S / N ratio is increased and noise resistance is improved.
  • the signal output is increased, the length of the signal line can be increased to 20m or more.
  • the Hall element drive circuit 34 was built in, the number of wires could be reduced.
  • FIG. 10 is a configuration diagram of the magnetic field detector in the magnetic encoder showing the fifth embodiment of the invention.
  • the magnetic field detection unit 3 receives the output signal from the magnetic field detection element unit 33, the magnetic field detection element unit 33 in which six Hall elements are integrated and arranged, the drive circuit 34 that supplies power to the magnetic field detection element, and the magnetic field detection element unit 33.
  • the sensor signal processing unit 36 for processing is configured.
  • the magnetic field detection element unit 33 is arranged on the rotation center axis of the rotating body 1 and detects a magnetic field in three axial directions on the XY plane perpendicular to the rotation axis.
  • FIG. 11 is an enlarged view of the magnetic field detection element unit.
  • the magnetic field detection element unit 33 includes a Hall element 331, 332, 333, 334, 335 with a plane perpendicular to the rotation axis and a magnetic field detection direction of 90, 150, 210, 270, 330, and 30 degrees, respectively. , 336 are formed using semiconductor technology.
  • the size of the magnetic field detection element unit 33 is 0.5 mm ⁇ , and the size of the magnetic field detection unit 3 is a square having a side of 5 mm.
  • This embodiment is different from the first embodiment in that the magnetic field detection element unit 33 is The point is that it detects a magnetic field in the three-axis direction on the vertical XY plane, and it has a three-phase to two-phase conversion circuit.
  • the magnetic field detecting element is a force in which two pairs of magnetic field detecting elements are provided at positions that are 180 degrees out of phase with each other.
  • Six magnetic field detection elements that detect magnetic fields in six directions including the opposite directions of 180 degrees are integrated and arranged, and the three-phase output signal from the magnetic field detection element unit 33 is also arranged in the magnetic field detection unit 3.
  • a sensor signal processing unit with a three-phase, two-phase conversion circuit that converts the signal into two phases is provided.
  • FIG. 12 is a graph showing the change in the magnetic field of the magnetic field detection element 33 when the permanent magnet rotates.
  • the disk-shaped permanent magnet 2 having parallel anisotropy magnetized parallel to the radial direction rotates.
  • the magnetic field change in the vicinity of the center of the magnetic field detection element unit 33 is shown.
  • the peak value of the magnetic field received by the Hall element is 0.25 ( ⁇ ), and the third harmonic component is 1.0e " 4 (T), so it is about 0.004% of the fundamental wave. It shows that a disk-like permanent magnet with parallel anisotropy generates a sinusoidal magnetic field with very little harmonic distortion.
  • the change in the magnetic field is converted into an electric signal by the magnetic field detection element unit 33.
  • FIG. 13 is a graph showing the signal output of the magnetic field detection element section.
  • the output waveform is a sinusoidal signal containing the second and third harmonic components, although not shown for the second harmonic.
  • the second harmonic component is generated because the center of the permanent magnet does not completely coincide with the center of the rotation axis and the center of the magnetic field detection element unit 33 due to an assembly error or the like. In other words, this occurs because the relative distance between the Hall elements 331 to 336 and the permanent magnet 2 varies slightly, depending on the rotation angle of the permanent magnet 2.
  • the Hall output voltage of the Hall element is not completely proportional to the detected magnetic field, and has a nonlinearity of about 1% of the ideal characteristics, so the third harmonic component is generated in the Hall element signal output.
  • Figure 14 shows the relationship between the detected magnetic flux density of the Hall element and the Hall output voltage. FFT analysis of the output voltage waveform of the Hall element was performed by applying a sinusoidal magnetic field without distortion, and the third harmonic component was included by 0.6%. This is due to the nonlinearity of the detected magnetic field and output voltage of the Hall element.
  • FIG. 15 is a circuit diagram of the sensor signal processing unit.
  • the sensor signal processing unit is composed of an input adjustment unit 360, a differential operation unit 370, and a three-phase to two-phase conversion unit 380.
  • the differential amplifiers 361 to 366 cancel the offset of the input signal and adjust the amplitude of each output signal to be constant.
  • Honore elements facing the differential operation unit 370! /, And each other! / That is, outputs of 331 and 334, 332 and 335, and 3 33 and 336 are input to differential amplification 371, 372, and 373.
  • outputs Val, Vbl, and Vcl with the harmonic components of the second multiple canceled are obtained.
  • the obtained Val, Vbl, and Vcl are input to the differential amplifiers 381 and 382, and Va and Vb in which the third-order multiple harmonic components are canceled are obtained.
  • the sensor signal processing section can reduce these harmonic components.
  • FIG. 16 is a graph showing the relationship between the second harmonic component and the amount of eccentricity.
  • the second harmonic component increases with the deviation (decentration) between the rotation center of the permanent magnet 2 and the center axis of the magnetic field detection element 33, but it is canceled by taking the differential of the Hall element outputs facing each other. Show you what you can do.
  • Fig. 17 is a graph showing the waveform of the output signal of the differential operation unit 370 of the sensor signal processing unit 36.
  • the output signals Val, Vbl, Vcl of the differential amplifiers 371, 372, 373 when the permanent magnet 2 is rotated at 6000 rpm Shows the development of
  • FIG. 18 is a graph obtained by performing FFT analysis on the output signal of the differential operation unit 370.
  • the output signal Val of the differential amplifier 371 is subjected to FFT analysis. It can be seen that the output signal Val ⁇ of the differential amplifier 371 contains 0.7% of the 3rd harmonic component due to the nonlinearity of the Hall output voltage of the Hall element.
  • FIG. 19 is a graph showing the waveform of the output signal of the sensor signal processing unit 36
  • FIG. 20 is a graph of the FFT analysis of the output signal of the three-phase / two-phase conversion unit.
  • the third-order harmonic component is reduced to 0.01% or less by the three-phase to two-phase converter 380.
  • FIG. 21 is a block diagram of the signal processing circuit 5.
  • 53 is a waveform shaping circuit for adjusting the amplitude and phase of a two-phase signal
  • 54 is an angle calculation circuit. Since the configuration of the waveform shaping circuit 53 is the same as that of the first embodiment, its description is omitted.
  • the waveform shaping circuit power output signals VA and VB are input to the angle calculation circuit 54, and an angle signal is generated by tangent calculation. This angle signal is transmitted to the host controller through communication circuit means (not shown).
  • the magnetic field detection element unit in which six magnetic field detection elements are integrated is arranged on the center of the rotation axis, and the rotation of the disk-shaped permanent magnet magnetized in one direction. Since the magnetic field on the axis is detected, a signal can be obtained with very little distortion.
  • the magnetic field detection element unit, the drive circuit, and the sensor signal processing unit are integrated and packaged in the magnetic field detection unit, a signal of higher harmonic components can be obtained, and electrostatic noise is noise resistance against electromagnetic noise. Performance has improved significantly.
  • the magnetic field detection element unit may be configured by three magnetic field detection elements.
  • Permanent magnets include other rare earth magnets, ferrite magnets, bonded magnets,
  • the Hall element is used as the magnetic field detection element.
  • the same effect can be obtained even when the magnetoresistive element is used.
  • the angle is obtained by digital calculation of a sine wave and cosine wave force, but the angle may be obtained by a phase tracking method, a multiplication method, a phase modulation method, or the like.
  • the third harmonic can be reduced by detecting a magnetic field in three axial directions using six magnetic field detecting elements.
  • five or ten magnetic field detecting elements are used. It is clear that the 5th-order harmonic component can be reduced by detecting the magnetic field in the 5-axis direction using.
  • the present invention can be applied to a magnetic encoder device that detects the rotation angle of a servo motor used as an actuator for a machine tool, a robot, or the like.

Landscapes

  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Transmission And Conversion Of Sensor Element Output (AREA)

Abstract

A magnetic encoder device having a reduced number of power supply wires for driving a magnetic field element and of output signal wires, low in cost, and having high degree of installation freedom. A circular plate-like permanent magnet (2) forming a magnetism generation body is magnetized vertically and in parallel to one direction relative to a rotating shaft (11) of a rotating body (1). A magnetic field detection section (6) is placed on a processing circuit substrate (4), at the center axis (10) of rotation of the rotating body (1). The magnetic field detection section (6) has two magnetic field detection elements (not shown) placed close to each other, and the detection elements are arranged to detect magnetic fields in planes vertical to the rotating shaft, in the directions that are different from each other. The magnetic field detection section (6) detects magnetic fields in the directions of two axes of X and Y on a X-Y plane vertical to the rotating shaft (11).

Description

明 細 書  Specification
磁気式エンコーダ装置  Magnetic encoder device
技術分野  Technical field
[0001] 本発明は、回転体の回転位置を検出する磁気式エンコーダ装置に関する。  The present invention relates to a magnetic encoder device that detects a rotational position of a rotating body.
背景技術  Background art
[0002] (従来例 1)  [0002] (Conventional example 1)
従来、高精度の位置情報を得る磁気式エンコーダとして、平面内で 2極に平行に磁 化した円板状の永久磁石が発生する磁界を検出し、回転体の位置の絶対値を検出 する磁気式エンコーダが開示されている (例えば特許文献 1参照)。  Conventionally, as a magnetic encoder that obtains highly accurate position information, a magnetic field generated by a disk-shaped permanent magnet magnetized parallel to two poles in a plane is detected, and the absolute value of the position of the rotating body is detected. An encoder is disclosed (for example, see Patent Document 1).
図 22は第 1従来技術における磁気式エンコーダの構成を示す斜視図である。 図において、 1は回転体、 2は回転体 1に回転軸 11を介して固定された永久磁石で 、回転軸 11に対して、垂直に一方向磁ィ匕されている。  FIG. 22 is a perspective view showing the configuration of the magnetic encoder in the first prior art. In the figure, 1 is a rotating body, 2 is a permanent magnet fixed to the rotating body 1 via a rotating shaft 11, and is magnetized in one direction perpendicular to the rotating shaft 11.
611乃至 614は磁界検出素子で、永久磁石 2に対して軸方向に空隙を介して配置 され固定体 7上に固定されている。磁界検出素子 611乃至 614は、周方向に互いに 機械角で 90度位相をずらして配置されており、回転体 1の回転に応じて永久磁石 2 が発生する磁界の変化を検出する。この検出信号を信号処理回路 5で回転角度に 変換し、回転体 1の絶対値位置を検出している。  Reference numerals 611 to 614 denote magnetic field detection elements, which are arranged on the permanent magnet 2 via a gap in the axial direction and fixed on the fixed body 7. The magnetic field detection elements 611 to 614 are arranged in the circumferential direction with a mechanical angle shifted by 90 degrees from each other, and detect a change in the magnetic field generated by the permanent magnet 2 according to the rotation of the rotating body 1. This detection signal is converted into a rotation angle by the signal processing circuit 5, and the absolute value position of the rotating body 1 is detected.
[0003] (従来例 2) [0003] (Conventional example 2)
また、回転体に取り付けられた平面内で 2極に平行に磁ィ匕された永久磁石が発生 する磁界を、軸方向に空隙を介して等間隔で配置した 6個の磁界検出素子で検出し 、回転体の位置の絶対値を検出するようにしたものが開示されている（例えば特許文 献 2参照)。  In addition, a magnetic field generated by a permanent magnet magnetized in parallel with two poles in a plane attached to the rotating body is detected by six magnetic field detecting elements arranged at equal intervals in the axial direction via gaps. A device that detects the absolute value of the position of a rotating body is disclosed (for example, see Patent Document 2).
図 23は第 2従来技術における磁気式エンコーダの構成を示す斜視図である。 図において、 1は回転体、 2は回転体 1に回転軸 11を介して固定された永久磁石で FIG. 23 is a perspective view showing a configuration of a magnetic encoder in the second prior art. In the figure, 1 is a rotating body, 2 is a permanent magnet fixed to the rotating body 1 via a rotating shaft 11.
、回転軸 11に対して、垂直に一方向磁ィ匕されている。 The rotating shaft 11 is magnetized in one direction perpendicularly.
621〜626は磁界検出素子で、磁界検出素子 621〜626は、機械角で 180度位 相がずれた位置に設けた 2個 1対の A1相検出素子 621と A2相検出素子 622、 B1 相検出素子 623と B2相検出素子 624、および C1相検出素子 625と C2相検出素子 626、計 3対のもので構成され、固定体 7上に配置されている。 621 to 626 are magnetic field detection elements, and magnetic field detection elements 621 to 626 are provided at a position that is 180 degrees out of phase with the mechanical angle. A pair of A1 phase detection elements 621 and A2 phase detection elements 622, B1 Phase detection element 623 and B2 phase detection element 624, and C1 phase detection element 625 and C2 phase detection element 626, consisting of a total of three pairs, are arranged on fixed body 7.
[0004] 図 24は、信号処理回路のブロック図である。 FIG. 24 is a block diagram of a signal processing circuit.
信号処理回路には、 A1相検出素子 621と A2相検出素子 622、 B1相検出素子 62 3と B2相検出素子 624、および C1相検出素子 625と C2相検出素子 626に対して、 それぞれ第 1差動増幅器 81、 82、 83が設けられている。第 1差動増幅器 81〜83は 、 1対の磁界検出素子同士の出力信号の差を取ることにより偶数次の高調波成分を 除去するものである。  The signal processing circuit includes a first detector for A1 phase detector 621 and A2 detector 622, B1 detector 623 and B2 detector 624, and C1 detector 625 and C2 detector 626, respectively. Differential amplifiers 81, 82, and 83 are provided. The first differential amplifiers 81 to 83 remove even-order harmonic components by taking the difference between the output signals of the pair of magnetic field detection elements.
さらに、第 1差動増幅器 81と 82、第 1差動増幅器 82と 83の後段には、それぞれ第 2差動増幅器 84、 85を設けてある。  Further, second differential amplifiers 84 and 85 are provided at the subsequent stage of the first differential amplifiers 81 and 82 and the first differential amplifiers 82 and 83, respectively.
この第 2差動増幅器 84、 85は、第 1差動増幅器 81と 82、第 1差動増幅器 82と 83 により偶数次の高調波成分を除去した後の差動出力信号を二つずつ組み合わせて 和を取ることにより、差動出力信号に含まれる 3次の高調波成分を除去し、ェンコ一 ダを高精度化していた。  The second differential amplifiers 84 and 85 combine two differential output signals after removing even-order harmonic components by the first differential amplifiers 81 and 82 and the first differential amplifiers 82 and 83, respectively. By taking the sum, the third-order harmonic component contained in the differential output signal was removed, and the encoder was highly accurate.
[0005] (従来例 3) [0005] (Conventional example 3)
また、回転軸に固定された円板状の永久磁石の円周上の一端に N極、他端に S極 を形成し、永久磁石と一定の空隙を隔てて、軸心上に磁気抵抗素子を対抗配置した 角度センサが開示されている (例えば特許文献 3参照)。  In addition, an N pole is formed at one end of the circumference of the disk-shaped permanent magnet fixed to the rotating shaft, and an S pole is formed at the other end, with a fixed gap and a magnetoresistive element on the axis. An angle sensor in which the above is arranged is disclosed (for example, see Patent Document 3).
図 25は第 3従来例における角度センサの斜視図、図 26は角度センサの回転角度 と出力電圧の関係を示すグラフである。  FIG. 25 is a perspective view of the angle sensor in the third conventional example, and FIG. 26 is a graph showing the relationship between the rotation angle of the angle sensor and the output voltage.
円板状の永久磁石 12が回転すると、その回転角度に応じて、磁気抵抗素子 13に 作用する磁界の強さが変化し、これにより磁気抵抗素子 13の抵抗が変化する。この 抵磁気抵抗素子 13の抵抗変化を電圧変化として検出すると、図 26に示すようなシャ フト 11の回転角度位置に応じた出力信号が得られる。磁気抵抗素子 13の出力電圧 は、シャフト 11がー方向に 90度回転する毎に、直線的に増力！]と減少を交互に繰り返 す。そして、この出力電圧波形の直線部分が、回転角度に比例することを利用してい る。  When the disk-shaped permanent magnet 12 rotates, the strength of the magnetic field acting on the magnetoresistive element 13 changes according to the rotation angle, and thereby the resistance of the magnetoresistive element 13 changes. When the resistance change of the magnetoresistive element 13 is detected as a voltage change, an output signal corresponding to the rotation angle position of the shaft 11 as shown in FIG. 26 is obtained. The output voltage of the magnetoresistive element 13 increases linearly every time the shaft 11 rotates 90 degrees in the negative direction! ] And decrease alternately. Then, the fact that the linear portion of the output voltage waveform is proportional to the rotation angle is utilized.
[0006] (従来例 4) また、回転体の回転軸上に磁石を取付け、異なる検出方向に配置された複数の磁 気抵抗素子を有する磁気センサを、磁石が回転する方向に垂直に設置して、物体の 回転を検出する回転検出器が開示されている（例えば特許文献 4参照)。 [0006] (Conventional example 4) In addition, a magnet is mounted on the rotating shaft of the rotating body, and a magnetic sensor having a plurality of magnetoresistive elements arranged in different detection directions is installed perpendicular to the direction in which the magnet rotates to detect the rotation of the object. A rotation detector is disclosed (for example, see Patent Document 4).
図 27は第 4従来技術における回転検出器の構成を示す斜視図である。 図において、 22は、円柱形の外形で、上面に N極と S極の 2極に着磁した永久磁石 FIG. 27 is a perspective view showing a configuration of a rotation detector in the fourth prior art. In the figure, 22 is a cylindrical outer shape, and a permanent magnet with two poles, N pole and S pole, on the top surface.
、 37は、磁気センサで、永久磁石 22の上面力も離れた位置に設置され、永久磁石 2, 37 is a magnetic sensor installed at a position where the upper surface force of the permanent magnet 22 is also separated, and the permanent magnet 2
2に対して、垂直方向の磁界を検出する磁気抵抗パターンと磁気検出面方向の磁界 を検出する磁気抵抗パターンが形成されて！、る。 On the other hand, a magnetoresistive pattern that detects the magnetic field in the vertical direction and a magnetoresistive pattern that detects the magnetic field in the direction of the magnetic detection surface are formed! RU
永久磁石 22が回転すると磁気センサ 37が磁界の回転を検出し、 1回転 1波形の信 号を出力する。出力の変化から回転体の回転を検出する。さらに、磁気センサ 37を 2 個設置した場合は、回転方向も検出できる。  When the permanent magnet 22 rotates, the magnetic sensor 37 detects the rotation of the magnetic field and outputs a signal of one waveform per rotation. The rotation of the rotating body is detected from the change in output. Furthermore, when two magnetic sensors 37 are installed, the direction of rotation can also be detected.
特許文献 1 :特開 2000— 65596号公報  Patent Document 1: Japanese Unexamined Patent Publication No. 2000-65596
特許文献 2：特開 2001 - 33277号公報  Patent Document 2: JP 2001-33277 A
特許文献 3：特公平 7 - 119619号公報  Patent Document 3: Japanese Patent Publication No. 7-119619
特許文献 4：特開平 7— 27776号公報  Patent Document 4: Japanese Patent Laid-Open No. 7-27776
発明の開示  Disclosure of the invention
発明が解決しょうとする課題  Problems to be solved by the invention
[0007] 第 1従来技術で開示された磁気式エンコーダは、回転体に取り付けられた永久磁 石が発生する磁界は歪の小さい正弦波状となるので高精度のエンコーダが得られる 。しかし磁界検出素子を 4個以上必要とするため、磁界検出素子を駆動する電源線 や出力信号線の本数が多くなる。従って、配線や磁界検出素子の設置などが複雑に なりコストが高くなる問題があった。また、磁界検出素子を等間隔で設置する必要が あるが、設置精度がエンコーダ精度に大きく影響する問題があった。さらに配線数が 多 、のでノイズを拾 、やすく信頼性が低!、問題があった。  [0007] In the magnetic encoder disclosed in the first prior art, the magnetic field generated by the permanent magnet attached to the rotating body is a sine wave with a small distortion, so that a highly accurate encoder can be obtained. However, since four or more magnetic field detection elements are required, the number of power lines and output signal lines for driving the magnetic field detection elements increases. Therefore, there is a problem that the installation of wiring and magnetic field detection elements becomes complicated and the cost increases. In addition, it is necessary to install the magnetic field detection elements at equal intervals, but there is a problem that the installation accuracy greatly affects the encoder accuracy. In addition, since there are many wires, noise is easily picked up and reliability is low!
[0008] また、第 2従来技術で開示された磁気式エンコーダ装置は、磁界検出素子のサイ ズが大きいため、各磁界検出素子を回転軸中心から離して設置する必要があり、磁 界検出部としてはサイズが大きくなる問題があった。また精度良く等間隔で配置する ことが難しいため、永久磁石の偏心や回転軸のぶれにより検出精度が劣化する問題 があった。さらに各磁界検出素子の特性バラツキがあり、 2次、 3次の整数倍の高調 波成分を完全に除去することができない問題があった。また永久磁石の近くに磁界 検出素子のみが搭載され、磁界検出素子を駆動する駆動回路や信号増幅回路は永 久磁石と離れて設置されているので、電源線や出力信号線の本数が多くなる問題や 、耐ノイズ性が低下する問題があった。 [0008] In addition, since the magnetic encoder device disclosed in the second prior art has a large size of the magnetic field detection element, it is necessary to install each magnetic field detection element away from the center of the rotation axis. There was a problem that the size becomes large. In addition, since it is difficult to arrange them at regular intervals with high accuracy, the detection accuracy deteriorates due to the eccentricity of the permanent magnet and the shake of the rotating shaft. was there. Furthermore, there was a variation in the characteristics of each magnetic field detection element, and there was a problem that it was not possible to completely remove the second and third order harmonic components. Also, only the magnetic field detection element is mounted near the permanent magnet, and the drive circuit and signal amplification circuit that drive the magnetic field detection element are installed away from the permanent magnet, so the number of power lines and output signal lines increases. There was a problem and noise resistance was lowered.
[0009] また、第 3従来技術で開示された磁気式エンコーダは、角度の検出範囲が出力電 圧の直線性を有する範囲に限定され、し力も低精度である。したがって 360度範囲の 全周にわたって、回転角度を高精度に検出できることを要求されるサーボモータなど には適用できな ヽ問題があつた。  [0009] In addition, the magnetic encoder disclosed in the third prior art is limited to a range in which the angle detection range has linearity of the output voltage, and the force is low in accuracy. Therefore, there was a problem that could not be applied to servo motors that are required to detect the rotation angle with high accuracy over the entire 360 ° range.
[0010] また、第 4従来技術で開示された回転検出装置は、粗い位置検出は可能であるが 、回転角度を高精度に検出できることを要求されるサーボモータなどには適用できな い問題があった。  In addition, the rotation detection device disclosed in the fourth prior art can detect a rough position, but cannot be applied to a servo motor or the like that is required to detect a rotation angle with high accuracy. there were.
[0011] 本発明はこのような問題点に鑑みてなされたものであり、構成が簡単で小型化でき The present invention has been made in view of such problems, and has a simple configuration and can be miniaturized.
、低コストで、さらに、永久磁石の偏心や回転軸のぶれに強ぐ信頼性の高い高精度 磁気式エンコーダ装置を提供することを目的とする。 Another object of the present invention is to provide a highly reliable magnetic encoder device that is low in cost and highly reliable against eccentricity of a permanent magnet and shake of a rotating shaft.
課題を解決するための手段  Means for solving the problem
[0012] 上記問題を解決するため、本発明は次のように構成したものである。  In order to solve the above problems, the present invention is configured as follows.
請求項 1に記載の発明は、回転体に固定され 2極に磁ィ匕された円板状又はリング 状の永久磁石と、前記永久磁石が発生する磁界を検出する磁界検出部と、前記磁 界検出部からの信号を処理する信号処理回路とを備え、前記回転体の絶対位置を 検出するようにした磁気式エンコーダ装置において、前記磁界検出部は、前記回転 体の回転軸方向に前記永久磁石と空隙を介して配置され、前記永久磁石の回転中 心軸の延長上に前記回転軸に垂直な面内の複数軸方向の磁界を検出する磁界検 出素子部を備えたことを特徴として 、る。  The invention according to claim 1 is a disk-shaped or ring-shaped permanent magnet fixed to a rotating body and magnetized in two poles, a magnetic field detector for detecting a magnetic field generated by the permanent magnet, and the magnetic And a signal processing circuit for processing a signal from a field detection unit, wherein the magnetic field detection unit detects the absolute position of the rotating body in the direction of the rotation axis of the rotating body. A magnetic field detecting element unit is provided, which is arranged through a magnet and a gap, and detects a magnetic field in a plurality of axial directions in a plane perpendicular to the rotation axis on an extension of a rotation center axis of the permanent magnet. RU
また、請求項 2に記載の発明は、前記複数軸方向が 2軸方向であることを特徴とし ている。  The invention according to claim 2 is characterized in that the plurality of axial directions are biaxial directions.
また、請求項 3に記載の発明は、前記複数軸方向が 3軸方向であることを特徴とし ている。 また、請求項 4に記載の発明は、前記磁界検出素子部は、前記各軸方向の磁界を 検出する磁界検出素子を半導体技術により近接して形成したものであることを特徴と している。 The invention according to claim 3 is characterized in that the plurality of axial directions are three axial directions. The invention described in claim 4 is characterized in that the magnetic field detection element section is formed by forming magnetic field detection elements for detecting magnetic fields in the respective axial directions close to each other by a semiconductor technology.
また、請求項 5に記載の発明は、前記磁界検出素子部は、前記各軸方向の磁界を 検出する磁界検出素子パッケージを近接して配置したことを特徴としている。  Further, the invention described in claim 5 is characterized in that the magnetic field detection element portion is arranged close to a magnetic field detection element package for detecting a magnetic field in each axial direction.
また、請求項 6に記載の発明は、前記磁界検出部は、前記磁界検出素子部と、前 記磁界検出素子部を駆動する駆動回路と、前記磁界検出素子部の出力信号を処理 する信号処理部を 1パッケージに集積したことを特徴としている。  In the invention according to claim 6, the magnetic field detection unit includes the magnetic field detection element unit, a drive circuit that drives the magnetic field detection element unit, and a signal processing that processes an output signal of the magnetic field detection element unit. The feature is that the parts are integrated in one package.
また、請求項 7に記載の発明は、前記永久磁石は、回転軸に垂直な面内で平行に 磁化されたことを特徴として 、る。  The invention according to claim 7 is characterized in that the permanent magnet is magnetized in parallel in a plane perpendicular to the rotation axis.
また、請求項 8に記載の発明は、前記永久磁石は、平行異方性を有した永久磁石 力 なることを特徴として 、る。  The invention according to claim 8 is characterized in that the permanent magnet has a permanent magnet force having parallel anisotropy.
発明の効果  The invention's effect
[0013] 請求項 1に記載の発明によると、磁界検出部が回転軸に垂直な面内の複数軸方向 の磁界を検出する磁界検出素子部を備えているので、磁界検出部 1個の簡単な構成 で回転角度を検出できる。それ故、リード本数が低減でき、製作'組み立てコストが低 減できる。  [0013] According to the invention described in claim 1, since the magnetic field detection unit includes the magnetic field detection element unit that detects magnetic fields in a plurality of axial directions in a plane perpendicular to the rotation axis, one simple magnetic field detection unit is provided. The rotation angle can be detected with a simple configuration. Therefore, the number of leads can be reduced, and manufacturing and assembly costs can be reduced.
また、磁界検出部が永久磁石の回転中心軸の延長上に配置されているので、回転 軸の偏心やぶれによる検出磁界の変動が小さくなり高精度のエンコーダが実現でき る。  In addition, since the magnetic field detector is arranged on the extension of the rotation center axis of the permanent magnet, the fluctuation of the detected magnetic field due to the eccentricity or shake of the rotation axis is reduced, and a highly accurate encoder can be realized.
また、永久磁石を、内部が中空のリング形状にすれば、モータなどの検出対象の回 転軸に永久磁石をマウントできる。従って、エンコーダと検出対象を一体ィ匕でき、構 成がシンプルで耐振動性が向上するとともに小型化できる。  Further, if the permanent magnet has a hollow ring shape, the permanent magnet can be mounted on a rotating shaft to be detected such as a motor. Therefore, the encoder and the detection target can be integrated, the configuration is simple, the vibration resistance is improved, and the size can be reduced.
[0014] また、請求項 2に記載の発明によると、磁界検出部が回転軸に垂直な面内の 2軸方 向の磁界を検出する磁界検出素子部を備えれば、磁界検出部のサイズを小さくでき[0014] According to the invention of claim 2, if the magnetic field detection unit includes a magnetic field detection element unit that detects a magnetic field in two axial directions in a plane perpendicular to the rotation axis, the size of the magnetic field detection unit Can be reduced
、簡単な構成で回転角度を検出できる。 The rotation angle can be detected with a simple configuration.
[0015] また、請求項 3に記載の発明によると、磁界検出部が回転軸に垂直な面内の 3軸方 向の磁界を検出する磁界検出素子部を備えれば、磁界検出部のサイズを小さくでき 、さらに、 2次および 3次の倍数の高調波成分をキャンセルした波形歪の極めて小さ[0015] According to the invention of claim 3, if the magnetic field detection unit includes a magnetic field detection element unit that detects a magnetic field in three axial directions in a plane perpendicular to the rotation axis, the size of the magnetic field detection unit Can be reduced In addition, the waveform distortion is canceled out by canceling the harmonic components of the second and third order multiples.
V、信号を出力することができる。 V, signal can be output.
[0016] また、請求項 4に記載の発明によると、磁界検出素子部の磁界検出素子を半導体 技術により近接して形成すれば、素子間の特性のノ ツキを小さくすることができ精 度の良い検出信号が得られる。 [0016] Further, according to the invention of claim 4, if the magnetic field detection elements of the magnetic field detection element portion are formed closer to each other by semiconductor technology, the fluctuation in characteristics between the elements can be reduced and the accuracy can be reduced. A good detection signal is obtained.
[0017] また、請求項 5に記載の発明によると、磁界検出素子パッケージ近接して配置して 磁界検出素子部を構成すれば、簡単な構成で回転軸の偏心やぶれによる検出磁界 の変動が小さい高精度のエンコーダが実現できる。 [0017] According to the invention described in claim 5, if the magnetic field detection element unit is configured in the vicinity of the magnetic field detection element package, the detection magnetic field variation due to eccentricity or shake of the rotating shaft is small with a simple configuration. A highly accurate encoder can be realized.
[0018] また、請求項 6に記載の発明によると、磁界検出素子部と駆動回路と信号処理部を[0018] According to the invention of claim 6, the magnetic field detection element unit, the drive circuit, and the signal processing unit are provided.
1パッケージに集積して磁界検出部を構成すれば、小形ィ匕が実現できるとともに、リ ード本数が低減でき、製作'組み立てコストが低減できる。さらに角度情報をデジタル 信号で上位コントローラへ通信できるので、耐ノイズ性が向上するとともに出力信号 線を長くできる。 If the magnetic field detector is configured by integrating in one package, a small size can be realized, the number of leads can be reduced, and manufacturing and assembly costs can be reduced. In addition, the angle information can be communicated to the host controller using digital signals, improving noise resistance and lengthening the output signal line.
[0019] また、請求項 7に記載の発明によると、永久磁石を回転軸に垂直な面内で平行に 磁化すれば、永久磁石が発生する磁界が歪の小さい正弦波状となり、高精度のェン コーダを提供できる。  [0019] According to the invention of claim 7, if the permanent magnet is magnetized in parallel in a plane perpendicular to the rotation axis, the magnetic field generated by the permanent magnet becomes a sine wave with a small distortion, and a highly accurate error is obtained. Can be provided.
[0020] また、請求項 8に記載の発明によると、永久磁石が平行異方性を有すれば、特別な 磁ィ匕装置を必要とせずに、容易に永久磁石を面内に平行に磁ィ匕することができる。 図面の簡単な説明  [0020] According to the invention described in claim 8, if the permanent magnet has parallel anisotropy, the permanent magnet can be easily magnetized in parallel in the plane without requiring a special magnetizing device. You can do it. Brief Description of Drawings
[0021] [図 1]本発明の第 1実施例を示す磁気式エンコーダの斜視図である。  FIG. 1 is a perspective view of a magnetic encoder showing a first embodiment of the present invention.
[図 2]本発明の第 1実施例における磁界検出部の拡大図である。  FIG. 2 is an enlarged view of a magnetic field detector in the first embodiment of the present invention.
[図 3]本発明の第 1実施例における信号処理回路のブロック図である。  FIG. 3 is a block diagram of a signal processing circuit in the first embodiment of the present invention.
[図 4]本発明の第 1実施例における波形整形回路の回路図である。  FIG. 4 is a circuit diagram of a waveform shaping circuit according to the first embodiment of the present invention.
[図 5]本発明の第 1実施例における磁界検出部の出力波形図である。  FIG. 5 is an output waveform diagram of the magnetic field detector in the first embodiment of the present invention.
[図 6]本発明の第 2実施例を示す磁気式エンコーダの斜視図である。  FIG. 6 is a perspective view of a magnetic encoder showing a second embodiment of the present invention.
[図 7]本発明の第 3実施例を示す磁界検出部の構成図である。  FIG. 7 is a configuration diagram of a magnetic field detector showing a third embodiment of the present invention.
[図 8]本発明の第 3実施例における信号処理回路のブロック図である。  FIG. 8 is a block diagram of a signal processing circuit according to a third embodiment of the present invention.
[図 9]本発明の第 4実施例を示す磁界検出部の構成図である。 [図 10]本発明の第 5実施例示す磁界検出部の構成図である。 FIG. 9 is a configuration diagram of a magnetic field detector showing a fourth embodiment of the present invention. FIG. 10 is a configuration diagram of a magnetic field detector according to a fifth embodiment of the present invention.
[図 11]本発明の第 5実施例における磁界検出部の拡大図である。  FIG. 11 is an enlarged view of a magnetic field detector in a fifth embodiment of the present invention.
[図 12]本発明の第 5実施例における磁界検出素子部の磁界の変化を示すグラフであ る。  FIG. 12 is a graph showing changes in the magnetic field of the magnetic field detection element unit in the fifth example of the present invention.
[図 13]本発明の第 5実施例における磁界検出素子部の信号出力を示すグラフである  FIG. 13 is a graph showing the signal output of the magnetic field detection element portion in the fifth embodiment of the present invention.
[図 14]ホール素子の検出磁束密度とホール出力電圧との関係を示すグラフである。 FIG. 14 is a graph showing the relationship between the detected magnetic flux density of the Hall element and the Hall output voltage.
[図 15]本発明の第 5実施例におけるセンサ信号処理部の回路図である。 FIG. 15 is a circuit diagram of a sensor signal processing unit in a fifth embodiment of the present invention.
[図 16]2次高調波成分と偏心量との関係を示すグラフである。 FIG. 16 is a graph showing the relationship between the second harmonic component and the amount of eccentricity.
[図 17]本発明の第 5実施例における差動演算部の出力信号の波形を示すグラフであ る。  FIG. 17 is a graph showing a waveform of an output signal of a differential operation unit in the fifth example of the present invention.
[図 18]本発明の第 5実施例における差動演算部の出力信号を FFT解析したグラフで ある。  FIG. 18 is a graph obtained by performing FFT analysis on the output signal of the differential operation unit in the fifth example of the present invention.
[図 19]本発明の第 5実施例における 3相 2相変換部の出力信号の波形を示すグラフ である。  FIG. 19 is a graph showing a waveform of an output signal of a three-phase / two-phase converter in the fifth embodiment of the present invention.
[図 20]本発明の第 5実施例における 3相 2相変換部の出力信号を FFT解析したダラ フである。  FIG. 20 is a diagram obtained by FFT analysis of the output signal of the three-phase / two-phase converter in the fifth embodiment of the present invention.
[図 21]本発明の第 5実施例における信号処理回路のブロック図である。  FIG. 21 is a block diagram of a signal processing circuit in a fifth example of the present invention.
[図 22]第 1従来技術における磁気式エンコーダの構成を示す斜視図である。 FIG. 22 is a perspective view showing a configuration of a magnetic encoder in the first prior art.
[図 23]第 2従来技術における磁気式エンコーダの構成を示す斜視図である。 FIG. 23 is a perspective view showing a configuration of a magnetic encoder in the second conventional technique.
[図 24]第 2従来技術における信号処理回路のブロック図である。 FIG. 24 is a block diagram of a signal processing circuit in the second prior art.
[図 25]第 3従来例における角度センサの斜視図である。 FIG. 25 is a perspective view of an angle sensor in a third conventional example.
[図 26]第 3従来例における角度センサの回転角度と出力電圧の関係を示すグラフで ある。  FIG. 26 is a graph showing the relationship between the rotation angle of the angle sensor and the output voltage in the third conventional example.
[図 27]第 4従来技術における回転検出器の構成を示す斜視図である。  FIG. 27 is a perspective view showing a configuration of a rotation detector in the fourth prior art.
符号の説明 Explanation of symbols
1 :回転体 1: Rotating body
10 :回転中心軸 1:回転軸10: Rotation center axis 1: Rotation axis
2:永久磁石2: Permanent magnet
3:磁気抵抗素子3: Magnetoresistive element
, 2' ：永久磁石 (発磁体）, 2 ': Permanent magnet (Magnetic body)
:磁界検出部: Magnetic field detector
1、 32、 33:磁界検出素子部1, 32, 33: Magnetic field detection element
11、 312:磁界検出素子 (ホール素子）11, 312: Magnetic field detection element (Hall element)
21、 322:磁界検出素子パッケージ (ホール素子パッケ31〜336：ホール素子21, 322: Magnetic field detection element package (Hall element package 31 to 336: Hall element
:ホール素子駆動回路 : Hall element drive circuit
5:増幅回路5: Amplifier circuit
6:センサ信号処理回路6: Sensor signal processing circuit
60:入力調整部60: Input adjustment section
61〜366：差動増幅器61-366: Differential amplifier
70:差動演算部70: Differential operation part
71〜373：差動増幅器71-373: Differential amplifier
0 :3相 2相変換部 0: 3-phase 2-phase converter
1、 382:差動増幅器 1, 382: differential amplifier
:処理回路基板: Processing circuit board
:信号処理回路: Signal processing circuit
1、 52:増幅器1, 52: Amplifier
:波形整形回路 : Waveform shaping circuit
1、 532:増幅器 1, 532: Amplifier
3:カロ算器 3: Karo arithmetic
4:減算器 4: Subtractor
5, 536:増幅器 5, 536: Amplifier
:角度演算回路 : Angle calculation circuit
1〜614：磁界検出素子 621〜626 :磁界検出素子 1 to 614: Magnetic field detection element 621 to 626: Magnetic field detection element
7 :固定体  7: Fixed body
発明を実施するための最良の形態  BEST MODE FOR CARRYING OUT THE INVENTION
[0023] 以下、本発明の実施の形態について図を参照して説明する。 Hereinafter, embodiments of the present invention will be described with reference to the drawings.
実施例 1  Example 1
[0024] 図 1は、本発明の第 1実施例を示す磁気式エンコーダの斜視図である。  FIG. 1 is a perspective view of a magnetic encoder showing a first embodiment of the present invention.
図 1において、 1は回転体、 2は回転体 1に回転軸 11を介して固定された発磁体を 構成する永久磁石で、図中の矢印で示すように回転軸 11に対して、垂直に一方向 に平行に磁ィ匕されている。 3は磁界検出部で、磁界検出部 3は信号処理回路 5ととも に処理回路基板 4上に設置されている。さらに磁界検出部 3は回転体 1の回転中心 軸 10上に設置された磁界検出素子部 31を備えている。磁界検出素子部 31は回転 軸 11に対して垂直な X— Y平面上の 2軸方向の磁界を検出し、磁界の検出方向は 互 ヽに機械角で 90度異なって 、る。  In FIG. 1, 1 is a rotating body, 2 is a permanent magnet constituting a magnet generator fixed to the rotating body 1 via a rotating shaft 11, and is perpendicular to the rotating shaft 11 as indicated by an arrow in the figure. Magnetized parallel to one direction. 3 is a magnetic field detector, and the magnetic field detector 3 is installed on the processing circuit board 4 together with the signal processing circuit 5. Further, the magnetic field detection unit 3 includes a magnetic field detection element unit 31 installed on the rotation center axis 10 of the rotating body 1. The magnetic field detection element unit 31 detects a magnetic field in the biaxial direction on the XY plane perpendicular to the rotation axis 11, and the detection direction of the magnetic field is mutually different by 90 degrees in mechanical angle.
[0025] 本実施例では、永久磁石 2として直径が 10mm、厚さが 2mmのサマリウムコバルト 磁石を一方向に平行に磁ィ匕したものを用いた。また永久磁石 2と 2mmの空隙を介し て、磁界検出部 3を回転中心軸 10上に配置した。  [0025] In this example, a permanent magnet 2 in which a samarium cobalt magnet having a diameter of 10 mm and a thickness of 2 mm was magnetized in parallel in one direction was used. In addition, the magnetic field detector 3 was arranged on the rotation center axis 10 through a gap of 2 mm with the permanent magnet 2.
[0026] 本実施例が第 1従来技術と異なる部分は、磁界検出部の構成である。  [0026] The difference of the present embodiment from the first prior art is the configuration of the magnetic field detector.
第 1従来技術では、回転体の回転中心に対して同心円上に配置し、永久磁石の周 方向に互いに機械角で 90度位相がずれて 、る 2個 1対の磁界検出素子を互いに 18 0度位相をずらした位置に 2対設けている。これに対して本実施例は、 2軸方向の磁 界を検出する磁界検出素子部を回転中心軸上に配置している。  In the first prior art, two pairs of magnetic field detecting elements are arranged on a concentric circle with respect to the rotational center of the rotating body, and are 90 degrees out of phase with each other in the circumferential direction of the permanent magnet. Two pairs are provided at different positions. On the other hand, in this embodiment, the magnetic field detecting element portion for detecting the magnetic field in the biaxial direction is arranged on the rotation center axis.
[0027] 図 2は本実施例における磁界検出部の拡大図である。  FIG. 2 is an enlarged view of the magnetic field detector in the present embodiment.
図において、 3は磁界検出部の一実施例を示すもので、磁界検出部 3の磁界検出 素子部 31には、平面内で磁界の検出方向が互いに機械角でほぼ 90度異なる磁界 検出素子であるホール素子 311、 312が半導体技術を用いて形成されている。ホー ル素子 311は X軸方向の磁界 Bxを検出し、ホール素子 312は Y軸方向の磁界 Byを 検出する。駆動端子 A、 駆動端子 Bはホール素子 311、 312の図示しない駆動回路 とつながっており、ホール素子 311、 312に駆動電流を流す。永久磁石 2が回転する とホール素子 311、 312は回転角度に対応した磁界 Bx、 Byを受け、正弦波と余弦波 のホール電圧 va、 vbを端子 va及び端子 vbカゝらそれぞれ出力する。なお磁界検出素 子咅 31の直径は 200 mであり、ホーノレ素子 311と 312の間隔は、 20 /z m以下であ る。したがって永久磁石 2から見れば、ホール素子 311と 312は、ほぼ同位置にある とみなすことができる。 In the figure, reference numeral 3 denotes an embodiment of the magnetic field detection unit. The magnetic field detection element unit 31 of the magnetic field detection unit 3 is a magnetic field detection element in which the detection directions of the magnetic field are different from each other by about 90 degrees in the plane. Certain Hall elements 311 and 312 are formed using semiconductor technology. Hall element 311 detects a magnetic field Bx in the X-axis direction, and Hall element 312 detects a magnetic field By in the Y-axis direction. Drive terminal A and drive terminal B are connected to a drive circuit (not shown) of Hall elements 311 and 312, and a drive current is passed through Hall elements 311 and 312. Permanent magnet 2 rotates The Hall elements 311 and 312 receive magnetic fields Bx and By corresponding to the rotation angle and output sine wave and cosine wave Hall voltages va and vb from the terminal va and the terminal vb, respectively. The diameter of the magnetic field detecting element 31 is 200 m, and the distance between the Honore elements 311 and 312 is 20 / zm or less. Therefore, when viewed from the permanent magnet 2, the Hall elements 311 and 312 can be regarded as being substantially in the same position.
[0028] 図 3は本実施例における信号処理回路のブロック図である。  FIG. 3 is a block diagram of the signal processing circuit in the present embodiment.
信号処理回路 5は、ホール素子 311の出力信号であるホール電圧 vaを増幅する増 幅器 51と、ホール素子 312のホール電圧 vbを増幅する増幅器 52と、波形整形回路 53と、回転角度を演算する角度演算回路 54とを設けてある。  The signal processing circuit 5 calculates an angle of rotation by an amplifier 51 that amplifies the Hall voltage va that is an output signal of the Hall element 311, an amplifier 52 that amplifies the Hall voltage vb of the Hall element 312, and a waveform shaping circuit 53. An angle calculation circuit 54 is provided.
[0029] なおホール素子 311と 312の感度の差異等で出力信号の振幅値が異なると角度 誤差の要因となる。このため、波形整形回路 53には振幅を同じ大きさにするための 振幅調整回路を設けている。さらに出力信号のオフセットをキャンセルするオフセット 補償回路、および出力信号の位相差を電気角で正確に 90度にする位相調整回路 を備えている。  [0029] Note that if the amplitude value of the output signal is different due to the difference in sensitivity between the Hall elements 311 and 312 or the like, an angular error is caused. Therefore, the waveform shaping circuit 53 is provided with an amplitude adjustment circuit for making the amplitude the same. Furthermore, an offset compensation circuit that cancels the offset of the output signal and a phase adjustment circuit that makes the phase difference of the output signal exactly 90 degrees in electrical angle are provided.
図 4は波形整形回路の回路図である。  Figure 4 is a circuit diagram of the waveform shaping circuit.
図において、 531及び 532は、オフセット補償回路を構成する演算増幅器、 533及 び 534は位相調整回路を構成する加算器 533及び減算器 534で、また、 535及び 5 36はこの位相調整された信号の振幅を調整する演算増幅器 (振幅調整回路)である 。演算増幅器 535及び 536の出力 VA、 VBは角度演算回路 54へ入力される。  In the figure, 531 and 532 are operational amplifiers constituting an offset compensation circuit, 533 and 534 are an adder 533 and subtractor 534 constituting a phase adjustment circuit, and 535 and 5 36 are phase-adjusted signals. This is an operational amplifier (amplitude adjustment circuit) that adjusts the amplitude of. The outputs VA and VB of the operational amplifiers 535 and 536 are input to the angle calculation circuit 54.
[0030] 次に、動作について説明する。 [0030] Next, the operation will be described.
永久磁石 2が 1回転すると、磁界検出部 3は回転角位置に応じた正弦波、余弦波の 磁束密度を検出し、図 5に示すようなホール電圧 va、vbを出力する。ホール電圧 va、 vbは、信号処理回路 5の増幅器 51及び 52で増幅された後、波形整形回路 53に入 力される。波形整形回路 53ではオフセット、位相、振幅が調整される。  When the permanent magnet 2 rotates once, the magnetic field detector 3 detects the magnetic flux density of the sine wave and cosine wave according to the rotation angle position, and outputs the Hall voltages va and vb as shown in FIG. The Hall voltages va and vb are amplified by the amplifiers 51 and 52 of the signal processing circuit 5 and then input to the waveform shaping circuit 53. In the waveform shaping circuit 53, the offset, phase, and amplitude are adjusted.
すなわち、増幅器 51及び 52で増幅された 2相信号 Va、 Vbは図 4に示す波形整形 回路の増幅器 531及び 532でオフセットが除去され、加算器 533及び減算器 534に 入力さ; 立相差が 90度となるように位相調整される。さらに、加算器 533及び減算器 534から出力された信号は増幅器 535及び 536で振幅調整される。この振幅調整さ れた波形整形回路 53からの 2相の出力信号 VA、 VBは、角度演算回路 54に入力さ れ、正接演算により角度信号が生成される。 That is, the two-phase signals Va and Vb amplified by the amplifiers 51 and 52 are offset from the amplifiers 531 and 532 of the waveform shaping circuit shown in FIG. 4 and input to the adder 533 and subtracter 534; the phase difference is 90 The phase is adjusted to a degree. Further, the amplitude of the signals output from the adder 533 and the subtracter 534 is adjusted by the amplifiers 535 and 536. This amplitude adjusted The two-phase output signals VA and VB from the waveform shaping circuit 53 are input to the angle calculation circuit 54, and an angle signal is generated by tangent calculation.
[0031] なお、回転体 1が偏心して回転するようなことがある場合は、検出した磁束密度の波 形は偏心量に応じて変位する。このため第 1従来技術では対向する磁界検出素子の 出力信号の差動をとり、偏心の影響をなくしていた。しかし本発明では、 2軸方向の 磁界 Bx、 Byを検出する磁界検出素子部は、ほぼ同位置にあるので、偏心の影響に よるホール電圧 va、 vbの振幅値の変化率は同じとなる。ホール電圧 va、 vbの波形整 形回路 53を通した出力 VA、 VBの正接演算により角度を求めているので、本発明で は、偏心の影響はキャンセルされ、第 2従来技術のように対向するホール素子出力の 差動をとる必要は無い。 [0031] When the rotating body 1 sometimes rotates eccentrically, the detected magnetic flux density waveform is displaced according to the amount of eccentricity. For this reason, in the first prior art, the output signals of the opposing magnetic field detection elements are differentiated to eliminate the influence of eccentricity. However, in the present invention, since the magnetic field detection element portions for detecting the magnetic fields Bx and By in the two-axis directions are substantially at the same position, the rate of change in the amplitude values of the Hall voltages va and vb due to the influence of eccentricity is the same. Since the angle is obtained by the tangent calculation of the output VA and VB through the waveform shaping circuit 53 of the Hall voltages va and vb, in the present invention, the influence of the eccentricity is canceled and the opposite as in the second prior art. There is no need to take the Hall element output differential.
なお波形整形回路 53および角度演算回路 54の処理機能はソフト処理によって行 つても良い。  The processing functions of the waveform shaping circuit 53 and the angle calculation circuit 54 may be performed by software processing.
[0032] 1回転 100万分割のエンコーダを基準エンコーダとして、本エンコーダを評価した が 1回転を 32000分割した極めて高 ヽ分解能の絶対位置信号が得られた。  [0032] This encoder was evaluated using an encoder with 1 million rotations per rotation as a reference encoder, but an absolute position signal with extremely high resolution was obtained with 32000 rotations per rotation.
[0033] 本実施例では永久磁石として、温度による特性変化が小さいサマリウムコバルト系 磁石を用いた力 永久磁石としては、他の希土類磁石、フェライト系磁石、ボンド磁石[0033] In this example, as a permanent magnet, a force using a samarium-cobalt-based magnet whose characteristic change due to temperature is small. As the permanent magnet, other rare earth magnets, ferrite-based magnets, bonded magnets are used.
、 SmFeN系磁石でも同様の効果が得られる。 The same effect can be obtained with SmFeN magnets.
[0034] 本実施例では、磁界検出素子としてホール素子を使用した場合について説明した 力 磁気抵抗素子を使用しても同様の効果が得られる。 In the present embodiment, the same effect can be obtained even if the force magnetoresistive element described in the case where the Hall element is used as the magnetic field detecting element.
[0035] また絶対角度の演算方法として、本実施例では、正弦波、余弦波力 ディジタル演 算処理する方法を採用したが、位相トラッキング方式ゃ遁倍方式、位相変調方式等 により角度を求めても良い。 [0035] Further, in this embodiment, as a method of calculating the absolute angle, a method of digital calculation processing of a sine wave and cosine wave force is adopted, but the angle is obtained by a phase tracking method, a multiplication method, a phase modulation method, or the like. Also good.
実施例 2  Example 2
[0036] 図 6は、本発明の第 2実施例を示す磁気式エンコーダの斜視図である。  FIG. 6 is a perspective view of a magnetic encoder showing a second embodiment of the present invention.
図において、 2'はリング形状の永久磁石である。  In the figure, 2 'is a ring-shaped permanent magnet.
永久磁石 2'として内径 3mm、外径が 10mm、厚さが 2mmのネオジゥム系ボンド磁 石を一方向に平行に磁ィ匕したものを用いた。  As the permanent magnet 2 ', a neodymium bonded magnet having an inner diameter of 3 mm, an outer diameter of 10 mm, and a thickness of 2 mm was magnetized in parallel in one direction.
磁界検出部 3は第 1実施例と同様に、回転体 1の回転中心軸 10上に設置された磁 界検出素子部 31を備え、回転軸 11に対して垂直な X— Y平面上の X、 Yの 2軸方向 の磁界を検出している。 As in the first embodiment, the magnetic field detector 3 is a magnetic field installed on the rotation center axis 10 of the rotating body 1. A field detection element unit 31 is provided to detect magnetic fields in the X and Y axes on the XY plane perpendicular to the rotation axis 11.
本実施例が第 1実施例と異なる点は、永久磁石にリング形状の永久磁石を用いた 点である。その他の構成については第 1実施例と同じであるのでその説明を省略す る。  This embodiment differs from the first embodiment in that a ring-shaped permanent magnet is used as the permanent magnet. Since other configurations are the same as those of the first embodiment, the description thereof is omitted.
[0037] このように本実施例ではリング形状の永久磁石を用いたので、モータなどの検出対 象の回転軸に永久磁石をマウントできる。従って、エンコーダと検出対象を一体化で き、構成がシンプルで耐振動性が向上するとともに小型化できる。  [0037] As described above, since the ring-shaped permanent magnet is used in the present embodiment, the permanent magnet can be mounted on the rotation shaft to be detected such as a motor. Therefore, the encoder and the detection target can be integrated, the configuration is simple, the vibration resistance is improved, and the size can be reduced.
実施例 3  Example 3
[0038] 図 7は本発明の第 3実施例を示す磁界検出部の構成図である。  FIG. 7 is a configuration diagram of a magnetic field detector showing a third embodiment of the present invention.
図において、 3は磁界検出部の一実施例を示すものである。  In the figure, 3 shows an embodiment of the magnetic field detector.
321、 322は一方向の磁界を検出するホール素子パッケージである。  Reference numerals 321 and 322 denote Hall element packages that detect a magnetic field in one direction.
ホール素子パッケージの大きさは 2mm角、厚さ 0. 5mmで、ホール素子パッケージ へ駆動電流を供給する図示しない 2個の駆動端子とホール電圧を出力する 2個の出 力端子を備えている。ホール素子パッケージは中心部に外径 50 mの図示しない磁 界検出素子を配置し、前記の駆動端子および信号出力端子と接続するともに、榭脂 でモールド成形されている。なおホール素子パーケージの磁界検出素子（図示せず )はパッケージ表面に平行な磁界を検出するように形成されている。  The Hall element package is 2mm square and 0.5mm thick. It has two drive terminals (not shown) that supply drive current to the Hall element package and two output terminals that output Hall voltage. In the Hall element package, a magnetic field detection element (not shown) having an outer diameter of 50 m is disposed at the center, and is connected to the drive terminal and the signal output terminal and molded with resin. A magnetic field detection element (not shown) of the Hall element package is formed so as to detect a magnetic field parallel to the package surface.
[0039] ホール素子パッケージ 321、 322は永久磁石 3と lmmの空隙を介して、磁界の検 出方向が互いに機械角で大体 90度になるように重ね合わせて回転中心軸 10上に 配置されている。なお、 2個のホール素子パッケージ 321と 322の磁界の検出方向が 機械角で正確に 90度になるように設置するのは難しいので、波形整形回路で位相 が 90度になるように調整する。 [0039] The Hall element packages 321 and 322 are arranged on the rotation center axis 10 so that the magnetic field detection directions are approximately 90 degrees with respect to each other via the permanent magnet 3 and the lmm gap. Yes. Since it is difficult to install the two Hall element packages 321 and 322 so that the magnetic field detection direction is exactly 90 degrees in terms of mechanical angle, adjust the waveform shaping circuit so that the phase is 90 degrees.
[0040] 図 8は本実施例における信号処理回路のブロック図である。 FIG. 8 is a block diagram of a signal processing circuit in the present embodiment.
ホール素子パッケージ 321から出力されるホール電圧 Va+、Va-およびホール素子 パッケージ 322から出力されるホール電圧 Vb+、Vb-は信号処理回路 5の増幅器 51 、 52にそれぞれ差動入力される。以降の波形整形回路 53および角度演算回路 54 の処理は第 1実施例と同じであるのでその説明を省略する。 また、第 1実施例と同様に、 1回転 100万分割のエンコーダを基準エンコーダとして 、本エンコーダを評価したが 16000分割した絶対位置信号が得られた。 The Hall voltages Va + and Va− output from the Hall element package 321 and the Hall voltages Vb + and Vb− output from the Hall element package 322 are differentially input to the amplifiers 51 and 52 of the signal processing circuit 5, respectively. Since the subsequent processing of the waveform shaping circuit 53 and the angle calculation circuit 54 is the same as that of the first embodiment, the description thereof is omitted. As in the first example, this encoder was evaluated using an encoder with 1 million rotations per rotation as a reference encoder, but an absolute position signal with 16000 divisions was obtained.
実施例 4  Example 4
[0041] 図 9は本発明の第 4実施例を示す磁界検出部の構成図である。  FIG. 9 is a configuration diagram of a magnetic field detector showing a fourth embodiment of the present invention.
図において、 3は磁界検出部の一実施例を示すものである。  In the figure, 3 shows an embodiment of the magnetic field detector.
2個のホール素子 311、 312を配置した磁界検出素子部 31とこのホール素子を駆 動するホール素子駆動回路 34およびホール素子出力信号の増幅回路を一パッケ一 ジに集積した。  The magnetic field detection element unit 31 in which two Hall elements 311 and 312 are arranged, the Hall element drive circuit 34 for driving the Hall element, and the amplification circuit for the Hall element output signal are integrated in one package.
[0042] このように、本実施例では一パッケージにすることで部品点数が少なくなり、組み立 て工数が減りコストが低減された。また信号が増幅されて出力されるので SN比が大き くなり耐ノイズ性が向上した。さらに信号出力が大きくなるので信号線の長さを 20m 以上にすることができた。また、ホール素子駆動回路 34を内蔵したので、配線数を削 減することが出来た。  Thus, in this example, the number of parts was reduced by using one package, the number of assembling steps was reduced, and the cost was reduced. In addition, since the signal is amplified and output, the S / N ratio is increased and noise resistance is improved. Furthermore, since the signal output is increased, the length of the signal line can be increased to 20m or more. In addition, since the Hall element drive circuit 34 was built in, the number of wires could be reduced.
実施例 5  Example 5
[0043] 図 10は、本発明の第 5実施例を示す磁気式エンコーダにおける磁界検出部の構 成図である。  FIG. 10 is a configuration diagram of the magnetic field detector in the magnetic encoder showing the fifth embodiment of the invention.
図において、磁界検出部 3は、ホール素子 6個を集積、配置した磁界検出素子部 3 3と、磁界検出素子に電源を供給する駆動回路 34と、磁界検出素子部 33からの出 力信号を処理するセンサ信号処理部 36から構成されている。  In the figure, the magnetic field detection unit 3 receives the output signal from the magnetic field detection element unit 33, the magnetic field detection element unit 33 in which six Hall elements are integrated and arranged, the drive circuit 34 that supplies power to the magnetic field detection element, and the magnetic field detection element unit 33. The sensor signal processing unit 36 for processing is configured.
磁界検出素子部 33は回転体 1の回転中心軸上に配置され、回転軸に対して垂直 な X— Y平面上の 3軸方向の磁界を検出する。  The magnetic field detection element unit 33 is arranged on the rotation center axis of the rotating body 1 and detects a magnetic field in three axial directions on the XY plane perpendicular to the rotation axis.
[0044] 図 11は磁界検出素子部の拡大図である。 FIG. 11 is an enlarged view of the magnetic field detection element unit.
磁界検出素子部 33には、回転軸に対して垂直な平面で磁界の検出方向がそれぞ れ 90、 150、 210、 270、 330、 30度であるホール素子 331, 332、 333, 334、 335 , 336が半導体技術を用いて形成されている。  The magnetic field detection element unit 33 includes a Hall element 331, 332, 333, 334, 335 with a plane perpendicular to the rotation axis and a magnetic field detection direction of 90, 150, 210, 270, 330, and 30 degrees, respectively. , 336 are formed using semiconductor technology.
磁界検出素子部 33のサイズは 0. 5mm φであり、磁界検出部 3のサイズは 1辺が 5 mmの正方形である。  The size of the magnetic field detection element unit 33 is 0.5 mmφ, and the size of the magnetic field detection unit 3 is a square having a side of 5 mm.
[0045] 本実施例が第 1実施例と異なる点は、磁界検出素子部 33が、回転軸 11に対して 垂直な X— Y平面上の 3軸方向の磁界を検出している点と、 3相 2相変換回路を備え ている点である。 This embodiment is different from the first embodiment in that the magnetic field detection element unit 33 is The point is that it detects a magnetic field in the three-axis direction on the vertical XY plane, and it has a three-phase to two-phase conversion circuit.
すなわち、第 1実施例では、磁界検出素子は、 2個 1対の磁界検出素子を互いに 1 80度位相をずらした位置に 2対設けている力 本実施例では、 3軸方向に対してそ れぞれの 180度反対の方向を含めた 6方向の磁界を検出する 6個の磁界検出素子 を集積、配置するとともに、磁界検出部 3に磁界検出素子部 33からの 3相の出力信 号を 2相に変換する 3相 2相変換回路を有するセンサ信号処理部を設けた。  That is, in the first embodiment, the magnetic field detecting element is a force in which two pairs of magnetic field detecting elements are provided at positions that are 180 degrees out of phase with each other. Six magnetic field detection elements that detect magnetic fields in six directions including the opposite directions of 180 degrees are integrated and arranged, and the three-phase output signal from the magnetic field detection element unit 33 is also arranged in the magnetic field detection unit 3. A sensor signal processing unit with a three-phase, two-phase conversion circuit that converts the signal into two phases is provided.
[0046] 次に、動作について説明する。 Next, the operation will be described.
先ず、磁界検出部の動作について説明する。  First, the operation of the magnetic field detector will be described.
図 12は永久磁石が回転したときの磁界検出素子部 33の磁界の変化を示すグラフ で、径方向に平行に磁化された平行異方性を有する円板状の永久磁石 2がー回転 するときの磁界検出素子部 33の中心近傍における磁界の変化を示している。  FIG. 12 is a graph showing the change in the magnetic field of the magnetic field detection element 33 when the permanent magnet rotates. When the disk-shaped permanent magnet 2 having parallel anisotropy magnetized parallel to the radial direction rotates. The magnetic field change in the vicinity of the center of the magnetic field detection element unit 33 is shown.
ホール素子が受ける磁界のピーク値は 0. 25 (Τ)、また 3次高調波成分は 1. 0e"4 ( T)であるので、基本波の約 0. 004%である。このことより、平行異方性を有する円板 状の永久磁石が極めて高調波歪の少ない正弦波状の磁界を発生することを示して いる。 The peak value of the magnetic field received by the Hall element is 0.25 (Τ), and the third harmonic component is 1.0e " 4 (T), so it is about 0.004% of the fundamental wave. It shows that a disk-like permanent magnet with parallel anisotropy generates a sinusoidal magnetic field with very little harmonic distortion.
[0047] 磁界の変化は磁界検出素子部 33によって、電気信号に変換される。  The change in the magnetic field is converted into an electric signal by the magnetic field detection element unit 33.
図 13は磁界検出素子部の信号出力を示すグラフである。  FIG. 13 is a graph showing the signal output of the magnetic field detection element section.
出力波形は、 2次高調波については図示しないが 2次および 3次の高調波成分を 含んだ正弦波状の信号となる。  The output waveform is a sinusoidal signal containing the second and third harmonic components, although not shown for the second harmonic.
[0048] 2次の高調波成分は、組み立て誤差等により永久磁石の中心と回転軸中心および 磁界検出素子部 33の中心が完全には一致しないために生ずる。すなわちホール素 子 331〜336と永久磁石間 2の相対距離が永久磁石 2の回転角度によって微小では あるが変化するために発生する。 [0048] The second harmonic component is generated because the center of the permanent magnet does not completely coincide with the center of the rotation axis and the center of the magnetic field detection element unit 33 due to an assembly error or the like. In other words, this occurs because the relative distance between the Hall elements 331 to 336 and the permanent magnet 2 varies slightly, depending on the rotation angle of the permanent magnet 2.
また、一般にホール素子のホール出力電圧は検出磁界に完全に比例せず、理想 特性に対して 1%程度の非直線性を有するために、ホール素子信号出力には 3次高 調波成分が発生する。図 14にホール素子の検出磁束密度とホール出力電圧との関 係を示す。 歪のない正弦波磁界を与えてホール素子の出力電圧波形の FFT解析を行ったが 、 3次高調波成分は 0. 6%含まれていた。これはホール素子の検出磁界と出力電圧 の非直線性によるものである。 Also, in general, the Hall output voltage of the Hall element is not completely proportional to the detected magnetic field, and has a nonlinearity of about 1% of the ideal characteristics, so the third harmonic component is generated in the Hall element signal output. To do. Figure 14 shows the relationship between the detected magnetic flux density of the Hall element and the Hall output voltage. FFT analysis of the output voltage waveform of the Hall element was performed by applying a sinusoidal magnetic field without distortion, and the third harmonic component was included by 0.6%. This is due to the nonlinearity of the detected magnetic field and output voltage of the Hall element.
[0049] 次に、センサ信号処理部 36の動作について説明する。 Next, the operation of the sensor signal processing unit 36 will be described.
図 15はセンサ信号処理部の回路図である。  FIG. 15 is a circuit diagram of the sensor signal processing unit.
センサ信号処理部は入力調整部 360、差動演算部 370及び 3相 2相変換部 380か ら構成され、先ず、 6個のホール素子 331乃至 336の出力信号は、それぞれ入力調 整部 360の差動増幅器 361乃至 366により、入力信号のオフセットがキャンセルされ 、また各出力信号の振幅の大きさを一定にするように調整される。次に、差動演算部 370にお!/、て互!/、に対向するホーノレ素子、すなわち 331と 334、 332と 335および 3 33と 336の出力を差動増幅 371、 372、 373へ入力し、 2次の倍数の高調波成分を キャンセルした出力 Val、 Vbl、 Vclを得る。次に、 3相 2相変換部 380において、得 られた Val、 Vbl、 Vclを差動増幅器 381、 382に入力し、 3次の倍数の高調波成分 をキャンセルした Va、 Vbを得る。  The sensor signal processing unit is composed of an input adjustment unit 360, a differential operation unit 370, and a three-phase to two-phase conversion unit 380. The differential amplifiers 361 to 366 cancel the offset of the input signal and adjust the amplitude of each output signal to be constant. Next, Honore elements facing the differential operation unit 370! /, And each other! /, That is, outputs of 331 and 334, 332 and 335, and 3 33 and 336 are input to differential amplification 371, 372, and 373. Then, outputs Val, Vbl, and Vcl with the harmonic components of the second multiple canceled are obtained. Next, in the three-phase to two-phase conversion unit 380, the obtained Val, Vbl, and Vcl are input to the differential amplifiers 381 and 382, and Va and Vb in which the third-order multiple harmonic components are canceled are obtained.
このように、磁界検出素子部からの出力信号が 2次および 3次の高調波成分を含ん でいても、センサ信号処理部によってこれらの高調波成分を低減できる。  As described above, even if the output signal from the magnetic field detection element section includes the second and third harmonic components, the sensor signal processing section can reduce these harmonic components.
[0050] 図 16は 2次高調波成分と偏心量との関係を示すグラフである。 FIG. 16 is a graph showing the relationship between the second harmonic component and the amount of eccentricity.
永久磁石 2の回転中心と磁界検出素子部 33の中心軸の偏位差 (偏心量）とともに 2 次高調波成分が増加するが、互いに対向するホール素子出力の差動をとることによ りキャンセルできることを示して 、る。  The second harmonic component increases with the deviation (decentration) between the rotation center of the permanent magnet 2 and the center axis of the magnetic field detection element 33, but it is canceled by taking the differential of the Hall element outputs facing each other. Show you what you can do.
[0051] 次に本実施例における測定結果について説明する。 [0051] Next, measurement results in this example will be described.
図 17はセンサ信号処理部 36の差動演算部 370の出力信号の波形を示すグラフで 、永久磁石 2を 6000rpmで回転したときの差動増幅器 371、 372、 373の出力信号 Val、 Vbl、 Vclの波开を示す。  Fig. 17 is a graph showing the waveform of the output signal of the differential operation unit 370 of the sensor signal processing unit 36. The output signals Val, Vbl, Vcl of the differential amplifiers 371, 372, 373 when the permanent magnet 2 is rotated at 6000 rpm Shows the development of
また、図 18は差動演算部 370の出力信号を FFT解析したグラフで、差動増幅器 3 71の出力信号 Valを FFT解析したものである。差動増幅器 371の出力信号 Val〖こ は、ホール素子のホール出力電圧の非直線性により、 0.7%の 3次高調波成分が含 まれていることが分かる。 図 19はセンサ信号処理部 36の部の出力信号の波形を示すグラフ、図 20は 3相 2 相変換部の出力信号を FFT解析したグラフである。 FIG. 18 is a graph obtained by performing FFT analysis on the output signal of the differential operation unit 370. The output signal Val of the differential amplifier 371 is subjected to FFT analysis. It can be seen that the output signal Val 〖of the differential amplifier 371 contains 0.7% of the 3rd harmonic component due to the nonlinearity of the Hall output voltage of the Hall element. FIG. 19 is a graph showing the waveform of the output signal of the sensor signal processing unit 36, and FIG. 20 is a graph of the FFT analysis of the output signal of the three-phase / two-phase conversion unit.
図 20に示すように、 3相 2相変換部 380によって、 3次高調波成分は 0. 01%以下 に低減されることが分かる。  As shown in FIG. 20, the third-order harmonic component is reduced to 0.01% or less by the three-phase to two-phase converter 380.
[0052] 次に信号処理回路 5の構成及び動作を説明する。 Next, the configuration and operation of the signal processing circuit 5 will be described.
図 21は信号処理回路 5のブロック図である。  FIG. 21 is a block diagram of the signal processing circuit 5.
図において、 53は 2相信号の振幅調整、位相調整を行う波形整形回路、 54は角度 演算回路である。波形整形回路 53の構成については、第 1実施例と同じであるので その説明を省略する。波形整形回路力 の出力信号 VA、 VBは、角度演算回路 54 に入力され、正接演算により角度信号が生成される。この角度信号は図示しない通 信回路手段を通じて上位コントローラへ送信される。  In the figure, 53 is a waveform shaping circuit for adjusting the amplitude and phase of a two-phase signal, and 54 is an angle calculation circuit. Since the configuration of the waveform shaping circuit 53 is the same as that of the first embodiment, its description is omitted. The waveform shaping circuit power output signals VA and VB are input to the angle calculation circuit 54, and an angle signal is generated by tangent calculation. This angle signal is transmitted to the host controller through communication circuit means (not shown).
[0053] 1回転 100万分割のエンコーダを基準エンコーダとして本エンコーダの性能を評価 したが 1回転を 124000分割した絶対位置信号が得られた。第 1従来技術のェンコ一 ダは同様な評価で 1回転 32000分割した分解能が得られていたが、本発明により分 解能が 4倍向上したことが分かる。 [0053] The performance of this encoder was evaluated using an encoder with 1 million divisions per rotation as a reference encoder, but an absolute position signal was obtained with 124000 divisions per revolution. The encoder of the first prior art had a resolution of 32,000 divisions per revolution with the same evaluation, but it can be seen that the present invention has improved the resolution by a factor of four.
[0054] このように、本実施例では、 6個の磁界検出素子を集積した磁界検出素子部を回転 軸中心上に配置し、一方向に磁ィ匕された円板状の永久磁石の回転軸上の磁界を検 出して 、るので、きわめて歪の小さ 、信号を得ることができる。 As described above, in this embodiment, the magnetic field detection element unit in which six magnetic field detection elements are integrated is arranged on the center of the rotation axis, and the rotation of the disk-shaped permanent magnet magnetized in one direction. Since the magnetic field on the axis is detected, a signal can be obtained with very little distortion.
また、磁界検出部に磁界検出素子部と駆動回路とセンサ信号処理部を集積し、パ 一ケージ化したので、さらに高調波成分の信号が得られるとともに、静電ノイズゃ電 磁ノイズに対する耐ノイズ性能が格段に向上した。  In addition, since the magnetic field detection element unit, the drive circuit, and the sensor signal processing unit are integrated and packaged in the magnetic field detection unit, a signal of higher harmonic components can be obtained, and electrostatic noise is noise resistance against electromagnetic noise. Performance has improved significantly.
なお、組み立て誤差等発生する 2次の高調波成分が充分小さい場合は、 3個の磁 界検出素子で磁界検出素子部を構成しても良い。  If the second-order harmonic component that generates an assembly error or the like is sufficiently small, the magnetic field detection element unit may be configured by three magnetic field detection elements.
[0055] 本実施例では永久磁石として、温度による特性変化が小さいサマリウムコバルト系 磁石を用いた。永久磁石としては、他の希土類磁石、フェライト系磁石、ボンド磁石、[0055] In this example, a samarium-cobalt magnet having a small characteristic change with temperature was used as the permanent magnet. Permanent magnets include other rare earth magnets, ferrite magnets, bonded magnets,
SmFeN系磁石でも同様の効果が得られる。 Similar effects can be obtained with SmFeN magnets.
[0056] また本実施例では、磁界検出素子としてホール素子を使用した場合について説明 したが、磁気抵抗素子を使用しても同様の効果が得られる。 [0057] また絶対角度の演算方法として、実施例では、正弦波、余弦波力 ディジタル演算 で角度を求めたが、位相トラッキング方式ゃ遁倍方式、位相変調方式等により角度を 求めても良い。 In this embodiment, the case where the Hall element is used as the magnetic field detection element has been described. However, the same effect can be obtained even when the magnetoresistive element is used. Further, as an absolute angle calculation method, in the embodiment, the angle is obtained by digital calculation of a sine wave and cosine wave force, but the angle may be obtained by a phase tracking method, a multiplication method, a phase modulation method, or the like.
[0058] また、本実施例では、 6個の磁界検出素子を用い、 3軸方向の磁界を検出すること によって 3次高調波が低減できることを示したが、 5個または 10個の磁界検出素子を 用いて 5軸方向の磁界を検出すれば 5次の高調波成分を低減できることは明らかで ある。  [0058] In the present embodiment, it has been shown that the third harmonic can be reduced by detecting a magnetic field in three axial directions using six magnetic field detecting elements. However, five or ten magnetic field detecting elements are used. It is clear that the 5th-order harmonic component can be reduced by detecting the magnetic field in the 5-axis direction using.
産業上の利用可能性  Industrial applicability
[0059] 本発明は、工作機やロボットなどのァクチユエータとして用いられるサーボモータの 回転角度を検出する磁気式ェンコーダ装置に適用できる。 The present invention can be applied to a magnetic encoder device that detects the rotation angle of a servo motor used as an actuator for a machine tool, a robot, or the like.

Claims

請求の範囲 The scope of the claims
[1] 回転体に固定され 2極に磁化された円板状又はリング状の永久磁石と、前記永久 磁石が発生する磁界を検出する磁界検出部と、前記磁界検出部からの信号を処理 する信号処理回路とを備え、前記回転体の絶対位置を検出するようにした磁気式ェ ンコーダ装置において、  [1] A disk-shaped or ring-shaped permanent magnet fixed to a rotating body and magnetized to two poles, a magnetic field detection unit for detecting a magnetic field generated by the permanent magnet, and a signal from the magnetic field detection unit In a magnetic encoder device comprising a signal processing circuit and detecting an absolute position of the rotating body,
前記磁界検出部は、前記回転体の回転軸方向に前記永久磁石と空隙を介して配 置され、前記永久磁石の回転中心軸の延長上に前記回転軸に垂直な面内の複数 軸方向の磁界を検出する磁界検出素子部を備えたことを特徴とする磁気式ェンコ一 ダ装置。  The magnetic field detection unit is arranged in the direction of the rotation axis of the rotating body via the permanent magnet and a gap, and extends in a plurality of axial directions in a plane perpendicular to the rotation axis on an extension of the rotation center axis of the permanent magnet. A magnetic encoder device comprising a magnetic field detecting element for detecting a magnetic field.
[2] 前記複数軸方向が 2軸方向であることを特徴とする請求項 1に記載の磁気式ェンコ ーダ装置。  [2] The magnetic encoder device according to [1], wherein the plurality of axial directions are biaxial directions.
[3] 前記複数軸方向が 3軸方向であることを特徴とする請求項 1に記載の磁気式ェンコ ーダ装置。  [3] The magnetic encoder apparatus according to [1], wherein the plurality of axial directions are three axial directions.
[4] 前記磁界検出素子部は、前記各軸方向の磁界を検出する磁界検出素子を半導体 技術により近接して形成したものであることを特徴とする請求項 1に記載の磁気式ェ ンコーダ装置。  [4] The magnetic encoder device according to [1], wherein the magnetic field detecting element section is formed by forming a magnetic field detecting element for detecting a magnetic field in each axial direction closer to each other by a semiconductor technology. .
[5] 前記磁界検出素子部は、前記各軸方向の磁界を検出する磁界検出素子パッケ一 ジを近接して配置したことを特徴とする請求項 1に記載の磁気式エンコーダ装置。  [5] The magnetic encoder device according to [1], wherein the magnetic field detection element unit includes magnetic field detection element packages that detect magnetic fields in the respective axial directions in close proximity to each other.
[6] 前記磁界検出部は、前記磁界検出素子部と、前記磁界検出素子部を駆動する駆 動回路と、前記磁界検出素子部の出力信号を処理する信号処理部を 1パッケージに 集積したことを特徴とする請求項 1に記載の磁気式エンコーダ装置。  [6] The magnetic field detection unit includes the magnetic field detection element unit, a drive circuit that drives the magnetic field detection element unit, and a signal processing unit that processes an output signal of the magnetic field detection element unit integrated in one package. The magnetic encoder device according to claim 1, wherein:
[7] 前記永久磁石は、回転軸に垂直な面内で平行に磁ィ匕されたことを特徴とする請求 項 1に記載の磁気式エンコーダ装置。  7. The magnetic encoder device according to claim 1, wherein the permanent magnet is magnetized in parallel in a plane perpendicular to the rotation axis.
[8] 前記永久磁石は、平行異方性を有した永久磁石力 なることを特徴とする請求項 7 に記載の磁気式エンコーダ装置。  8. The magnetic encoder device according to claim 7, wherein the permanent magnet has a permanent magnet force having parallel anisotropy.
PCT/JP2006/321870 2005-11-14 2006-11-01 Magnetic encoder device WO2007055135A1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP2007544107A JPWO2007055135A1 (en) 2005-11-14 2006-11-01 Magnetic encoder device

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
JP2005328265 2005-11-14
JP2005-328265 2005-11-14
JP2006105308 2006-04-06
JP2006-105308 2006-04-06

Publications (1)

Publication Number Publication Date
WO2007055135A1 true WO2007055135A1 (en) 2007-05-18

Family

ID=38023140

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/JP2006/321870 WO2007055135A1 (en) 2005-11-14 2006-11-01 Magnetic encoder device

Country Status (3)

Country Link
JP (1) JPWO2007055135A1 (en)
TW (1) TW200730799A (en)
WO (1) WO2007055135A1 (en)

Cited By (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2011030676A1 (en) * 2009-09-08 2011-03-17 Ntn株式会社 Rotational angle detecting sensor
WO2011080935A1 (en) * 2009-12-28 2011-07-07 株式会社ショーワ Relative angle detection device, rotation angle detection device, relative angle detection method, and rotation angle detection method
CN102401665A (en) * 2011-11-16 2012-04-04 宁波麦克斯电子科技有限公司 New motor magnetic encoder
JP2012215415A (en) * 2011-03-31 2012-11-08 Oriental Motor Co Ltd Absolute encoder apparatus and motor
JP2014199184A (en) * 2013-03-29 2014-10-23 Tdk株式会社 Magnetic sensor system
JP2017161553A (en) * 2017-06-22 2017-09-14 株式会社リコー Rotation angle detector, motor system, image processing device, and rotation angle detection method
KR101798919B1 (en) * 2016-01-25 2017-11-17 엘지전자 주식회사 Rotating electric machine
JP2019002942A (en) * 2013-10-25 2019-01-10 株式会社リコー Rotation detection device and rotation detection method
CN111750903A (en) * 2020-07-07 2020-10-09 哈尔滨理工大学 Winding integrated magnetoelectric encoder and independent calibration method thereof
JP2020176933A (en) * 2019-04-19 2020-10-29 三菱電機株式会社 Angle detection device

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH10232141A (en) * 1997-02-20 1998-09-02 Alps Electric Co Ltd Method for magnetizing magnetic body and magnetic potentiometer using the same
JP2002071381A (en) * 2000-08-21 2002-03-08 Sentron Ag Sensor for detection of direction of magnetic field
JP2002303536A (en) * 2001-04-03 2002-10-18 Alps Electric Co Ltd Rotation angle detecting sensor
JP2003070284A (en) * 2001-06-11 2003-03-07 Sony Corp Servo actuator and its position detector

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH10232141A (en) * 1997-02-20 1998-09-02 Alps Electric Co Ltd Method for magnetizing magnetic body and magnetic potentiometer using the same
JP2002071381A (en) * 2000-08-21 2002-03-08 Sentron Ag Sensor for detection of direction of magnetic field
JP2002303536A (en) * 2001-04-03 2002-10-18 Alps Electric Co Ltd Rotation angle detecting sensor
JP2003070284A (en) * 2001-06-11 2003-03-07 Sony Corp Servo actuator and its position detector

Cited By (19)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102472637A (en) * 2009-09-08 2012-05-23 Ntn株式会社 Rotational angle detecting sensor
JP2011058870A (en) * 2009-09-08 2011-03-24 Ntn Corp Rotation angle detection sensor
US8896297B2 (en) 2009-09-08 2014-11-25 Ntn Corporation Rotating angle detecting sensor
WO2011030676A1 (en) * 2009-09-08 2011-03-17 Ntn株式会社 Rotational angle detecting sensor
US8810237B2 (en) 2009-12-28 2014-08-19 Showa Corporation Relative angle detection device, rotation angle detection device, relative angle detection method, and rotation angle detection method
WO2011080935A1 (en) * 2009-12-28 2011-07-07 株式会社ショーワ Relative angle detection device, rotation angle detection device, relative angle detection method, and rotation angle detection method
GB2489350A (en) * 2009-12-28 2012-09-26 Showa Corp Relative angle detection device,rotation angle detection device, relative angle detection method and rotation angle detection method
CN102667412A (en) * 2009-12-28 2012-09-12 株式会社昭和 Relative angle detection device, rotation angle detection device, relative angle detection method, and rotation angle detection method
JP5611238B2 (en) * 2009-12-28 2014-10-22 株式会社ショーワ Relative angle detection device, rotation angle detection device, relative angle detection method, and rotation angle detection method
GB2489350B (en) * 2009-12-28 2016-10-05 Showa Corp Relative angle detection device, rotation angle detection device, relative angle detection method and rotation angle detection method
JP2012215415A (en) * 2011-03-31 2012-11-08 Oriental Motor Co Ltd Absolute encoder apparatus and motor
CN102401665A (en) * 2011-11-16 2012-04-04 宁波麦克斯电子科技有限公司 New motor magnetic encoder
US9200884B2 (en) 2013-03-29 2015-12-01 Tdk Corporation Magnetic sensor system including three detection circuits
JP2014199184A (en) * 2013-03-29 2014-10-23 Tdk株式会社 Magnetic sensor system
JP2019002942A (en) * 2013-10-25 2019-01-10 株式会社リコー Rotation detection device and rotation detection method
KR101798919B1 (en) * 2016-01-25 2017-11-17 엘지전자 주식회사 Rotating electric machine
JP2017161553A (en) * 2017-06-22 2017-09-14 株式会社リコー Rotation angle detector, motor system, image processing device, and rotation angle detection method
JP2020176933A (en) * 2019-04-19 2020-10-29 三菱電機株式会社 Angle detection device
CN111750903A (en) * 2020-07-07 2020-10-09 哈尔滨理工大学 Winding integrated magnetoelectric encoder and independent calibration method thereof

Also Published As

Publication number Publication date
TW200730799A (en) 2007-08-16
JPWO2007055135A1 (en) 2009-04-30

Similar Documents

Publication Publication Date Title
JP5120384B2 (en) Rotation angle detection device, rotator, and rotation angle detection method
WO2007055135A1 (en) Magnetic encoder device
JP4324813B2 (en) Rotation angle detector and rotating machine
JP4836058B2 (en) Magnetic encoder device
US8471552B2 (en) Rotational angle-measurement apparatus and rotational speed-measurement apparatus
JP4858855B2 (en) Rotation angle detector and rotating machine
US8664943B2 (en) Position detecting apparatus
JP5853046B2 (en) Magnetic field measuring device
JP5245114B2 (en) Position detection device
JP5613839B2 (en) Method and apparatus for absolute positioning of a moving object
JP4900837B2 (en) Rotation angle detector and rotating machine
CN110418942B (en) Rotary sensor
JP2020153806A (en) Rotation angle detector
EP1371937B1 (en) Rotating angle detector and device using the detector
JP5201493B2 (en) Position detection device and linear drive device
JP4900838B2 (en) Position detection device and linear drive device
WO2009084346A1 (en) Magnetic encoder
JP5724326B2 (en) Rolling bearings with sensors and automobiles, railway vehicles, steelmaking facilities, machine tools using rolling bearings with sensors
CN117040206B (en) High-precision servo motor and electrical equipment
CN117411247B (en) Industrial servo motor and electrical equipment
JP2005172441A (en) Angle and angular velocity integrated detector
JP2021135116A (en) Angle detection device and control device for rotary electric machine
CN117394609A (en) Permanent magnet synchronous servo motor and electrical equipment
JP2005017056A (en) Magnetic encoder device
JP2005030959A (en) Magnetic encoder device

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application
ENP Entry into the national phase

Ref document number: 2007544107

Country of ref document: JP

Kind code of ref document: A

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 06822799

Country of ref document: EP

Kind code of ref document: A1