Classifications

• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01P—MEASURING LINEAR OR ANGULAR SPEED, ACCELERATION, DECELERATION, OR SHOCK; INDICATING PRESENCE, ABSENCE, OR DIRECTION, OF MOVEMENT
  • G01P3/00—Measuring linear or angular speed; Measuring differences of linear or angular speeds
  • G01P3/42—Devices characterised by the use of electric or magnetic means
  • G01P3/44—Devices characterised by the use of electric or magnetic means for measuring angular speed
  • G01P3/48—Devices characterised by the use of electric or magnetic means for measuring angular speed by measuring frequency of generated current or voltage
  • G01P3/481—Devices characterised by the use of electric or magnetic means for measuring angular speed by measuring frequency of generated current or voltage of pulse signals
  • G01P3/488—Devices characterised by the use of electric or magnetic means for measuring angular speed by measuring frequency of generated current or voltage of pulse signals delivered by variable reluctance detectors
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01P—MEASURING LINEAR OR ANGULAR SPEED, ACCELERATION, DECELERATION, OR SHOCK; INDICATING PRESENCE, ABSENCE, OR DIRECTION, OF MOVEMENT
  • G01P3/00—Measuring linear or angular speed; Measuring differences of linear or angular speeds
  • G01P3/42—Devices characterised by the use of electric or magnetic means
  • G01P3/44—Devices characterised by the use of electric or magnetic means for measuring angular speed
  • G01P3/48—Devices characterised by the use of electric or magnetic means for measuring angular speed by measuring frequency of generated current or voltage
  • G01P3/481—Devices characterised by the use of electric or magnetic means for measuring angular speed by measuring frequency of generated current or voltage of pulse signals
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10S388/00—Electricity: motor control systems
  • Y10S388/907—Specific control circuit element or device
  • Y10S388/912—Pulse or frequency counter

Definitions

• the present invention relates to a motor speed detecting device, and more particularly to a motor speed detecting device using a toothed tooth having a notched groove and a magnetic sensor attached to a rotating eclipse of the motor.
• a conventional motor speed detector has a cord circle made of a glass plate or the like attached to the rotating shaft of the motor, and the opaque portion provided on the code disc is a light source and an optical sensor.
• This device obtains an electrical signal from an optical sensor by passing through the gap, amplifies the electrical signal, shapes the waveform, and obtains a pulse train corresponding to the rotation speed. One pulse in one rotation and two pulses in one rotation. The device can determine the rotational speed of the motor by determining the number of these pulses per time.
• the above-described speed detecting device has a problem that it cannot be applied when the detected rotating wheel is hollow.
• an electric motor is used to drive a machine tool such as a lathe, it is necessary to make the driven rotary shaft hollow and penetrate the rod-shaped workpiece because of the mechanism that sends out the workpiece.
• the device using the code circle cannot be used due to its structure.
• the device using the code disk also had adverse effects such as light drying due to other light sources, and the accuracy was not always sufficient.
• the present invention is proposed to solve the above-mentioned problems in the conventional device.
• the object of the present invention can also be applied to a case where the rotating gear is hollow such as a lathe, etc., and the inspection accuracy corresponding to the number of notched grooves of the gear is increased by about 4 times without increasing the number.
• An object of the present invention is to provide a speed detecting device that can be improved.
• a first tooth band and a plurality of notches formed of a ferromagnetic material having one notch groove attached to a rotating shaft of a motor driven by a motor driving unit are provided.
• a second magnetic sensor that outputs two signals that are in phase with the detected signal, and a detection circuit that receives the outputs of the first and second magnetic sensors and detects the outputs.
• a first differential amplification circuit for calculating a difference between two signals from the first magnetic sensor, an output from the first differential amplifier circuit
• a first comparison circuit that compares the two signals with a reference voltage
• a second difference amplification circuit that receives two sets of signals from the second magnetic sensor that are in opposite phase with each other and obtains the difference therebetween.
• the third differential multiplying circuit when the phase of the output waveform of the magnetic sensor corresponding to the width of the notch groove is set to 180 degrees after receiving the power of the second and third differential amplifier circuits.
• a vector combining / comparing circuit 22.5 degrees phase difference Q degree, 22.5 degrees-replacement 45 degrees, 67.5 degrees, 90 degrees, 12.5 degrees, 135 degrees, and 157.5 degrees
• the signal having each phase is obtained and compared with the reference voltage to create eight square wave trains.
• a vector combining / comparing circuit a logic circuit for performing a logic operation on an output of the vector combining / comparing circuit, a first inverting amplifying circuit for inverting and amplifying an output of the second differential amplifier circuit, and A second inverting amplifier circuit for inverting and amplifying an output of the third differential amplifier circuit, wherein a sine wave output of the first and second inverting amplifier circuits is supplied to the motor via the motor driving unit.
• FIG. 1 is a diagram showing a schematic configuration of a motor speed detecting device as one embodiment of the present invention
• FIG. 2 is a diagram showing the gear and the magnetic sensor unit in FIG. 1
• FIG. 3 is a diagram showing the first gear and the first magnetic sensor in FIG. 2
• FIG. 4 is a diagram showing a second gear and a second magnetic sensor in FIG. 2,
• Fig. 5 is a waveform diagram showing the output waveform of the magnetic sensor in Fig. 2,
• Fig. 6A and Fig. 6B are block circuit diagrams of the detection circuit in Fig. 1
• Fig. 7 is a circuit diagram of the vector synthesis comparator in Figs. 6A and 6B, and
• FIG. 8 is a schematic diagram showing signal waveforms in the circuits of FIGS. 6A and 6B.
• FIG. 1 shows a schematic structure of an electric motor distance detecting device as one embodiment of the present invention
• FIG. 2 shows its teeth and a magnetic sensor unit.
• This device has an electric motor 1 having a rotating gear 2, a first gear 3, a second gear 4, a first air sensor 5, a second magnetic sensor 6, a detection circuit 8, and a motor motor. It is equipped with two bits.
• Dentifrices 3 and 4 consist of tonics and are fixed to the rotating shaft 2--. - ⁇
• the gear 3 is provided with one notch groove 31 as shown in FIG.
• a magnetic sensor 5 is provided facing the tooth 3.
• the magnetic sensor 5 includes a magnetoresistive effect element (indicated by a resistance symbol in the figure) and a permanent magnet (not shown). Assuming that the width of the notch verse 31 is S, the magnetoresistive effect element is arranged at an interval of / 2 on the circumferential quotient of the gear 3.
• the permanent magnet is arranged so as to sandwich the magnetoresistive effect element between the permanent magnet and the gear 3. When the cutout groove of the tooth 3 faces the permanent magnet, the magnetic field applied to the magnetoresistive effect element is weakened.
• the magnetoresistive effect element has the property that the electric resistance value changes according to the strength of the magnetic field. Therefore, as shown in FIG. 3, when the magnetoresistive element is read in and the power is applied, and the notch groove of the gear 3 passes near the magnetic sensor 5, the two outputs Z and Z of the magnetic sensor 5 Z is the i-shaped waveform as shown in Fig. 5 (1).
• Replacement The gear 4 is provided with a plurality of notched grooves as shown in FIG. In the figure, the width of the groove is shown enlarged for convenience of description, and the notch groove uniformly provided over the entire circumference is abbreviated by a perforated line.
• the magnetic sensor 6 is designed to obtain A and B outputs corresponding to the Z and Z outputs of the magnetic sensor 5, as well as inverted outputs of A and B (outputs 180 degrees out of phase) and B.
• the magnetoresistive element is twice as large as the magnetic sensor 5.
• the A and B outputs correspond to the A and B output elements, each of which is arranged at an interval of 2.
• each element is arranged at an interval of 1/2, a power supply is connected to the opposite polarity, and the element group is arranged at a distance of ⁇ 2 from the element group.
• the output of the magnetic sensor 6 has the waveforms (2) and (3) shown in FIG.
• the gear 4 passes near the permanent magnet, the strength of the magnetic field is brought about and the output signal is obtained by changing the resistance of the magnetoresistive element. Same as in the case.
• FIGS. 6A and 6B show block diagrams of the detection circuit 8.
• the outputs Z and Z from the magnetic sensor 5 are supplied to a differential amplifier 813 as a first differential amplifier, and the difference is obtained.
• the difference signal is compared with a reference voltage, for example, 2.5 volts, in a comparator 849 as a first comparison circuit, and one square wave is output via a driver 873 for each rotation of the gear.
• Output A and output from the magnetic sensor 6 are replaced with the second differential amplifier circuit.
• the difference is calculated by the differential amplifier 811 as a differential amplifier 811, and the difference is obtained through the comparator 841, the vector combining comparators 842 to 844 constituting the vector combining / comparing circuit, and the inverter 831. This is provided to the vector synthesis comparators 846 to 848 that form a comparison circuit.
• the outputs B and B from the magnetic sensor 6 are applied to a difference amplifier 812 as a third differential amplifier circuit, and the difference is obtained, and the vectors constituting the comparator 845 and the vector combining / comparing circuit are obtained. It is associated with the composite comparators 842 to 844 and 846 to 848.
• the vector combining comparators 842, 843, 844, 846, 847, and 848 each include an operational amplifier 91 and a resistor as shown in FIG. Resistance value: Different value in each vector combining ratio. Considering the phase of the output signal S (811) of the differential amplifier 811 as a reference, the output signal S (812) of the differential amplifier 812 has a phase difference of 90 degrees. And S
• a signal having a desired phase difference can be obtained. That is, a signal S (811) having a phase difference of 0 degree is applied to the input terminal IN 1 in FIG.
• a signal with a phase difference of 22.5 degrees is supplied to the input of the mino amplifier 91 and compared with a reference voltage (Vref), for example, 2.5 volts, and a square wave signal with a phase difference of 22.5 degrees is input. Is forced.
• R 2 ZR 1 Select resistors R 1 and R 2 so that I tanll2.5 * I is added, and obtain a square wave with a phase difference of 112.5 'at the output.
• the vector synthesis comparator 847 has R 2 /
• the signal S (811) is supplied to the comparator 841 and is compared with the reference voltage to output a square wave having a phase difference of 0 degree.
• the signal S (812) is supplied to the comparator 845, and a signal having a phase difference of 90 degrees is output.
• the signals S (841) and S (843) are applied to an extrinsic transfer gate 851 to obtain an output signal S (851).
• Signal S (842) and S (844) is applied to the exclusive OR gate 852 outputs presumed dead, switch 0
• the signal S (852) is obtained.
• the signals S (845) and S (847) are applied to the exclusive OR gate 853 to obtain the output signal S (853).
• Signals S (846) and S (848) are applied to exclusive association gate 854 to obtain output signal S (854).
• the signals S (851) and S (853) are applied to an OR gate 861 to obtain an output i signal S (861).
• Signals S (852) and S (854) are applied to OR gate 862 to obtain output signal S (862).
• the signal S (861) is the signal A and the signal S obtained from A.
• a sine wave signal is supplied to the motor-driven drive unit 7 via the inverting amplifier 822 as a second inverting amplifier circuit.
• 3 ⁇ 4 A sine wave signal per sine wave, a sine wave signal having a phase difference of 90 degrees with respect to the sine wave signal, and a square wave signal having a phase difference of 90 degrees with respect to the frequency of the sine signal are obtained. .

Landscapes

• Physics & Mathematics (AREA)
• General Physics & Mathematics (AREA)
• Transmission And Conversion Of Sensor Element Output (AREA)
• Control Of Motors That Do Not Use Commutators (AREA)
• Control Of Electric Motors In General (AREA)

Priority Applications (1)

Applications Claiming Priority (2)

Publications (1)

Family

ID=14894961

Family Applications (1)

Country Status (5)

Families Citing this family (12)

Citations (7)

Family Cites Families (12)

• 1983
  • 1983-07-11 JP JP58124822A patent/JPS6017364A/ja active Granted
• 1984
  • 1984-07-11 EP EP84902815A patent/EP0149680B1/en not_active Expired
  • 1984-07-11 DE DE8484902815T patent/DE3484506D1/de not_active Expired - Lifetime
  • 1984-07-11 WO PCT/JP1984/000358 patent/WO1985000430A1/ja active IP Right Grant
  • 1984-07-11 US US06/711,535 patent/US4551662A/en not_active Expired - Fee Related

Patent Citations (7)

Non-Patent Citations (1)

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