JP3362196B2 - Drive control device for brushless DC motor - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to drive control of a three-phase axial type brushless DC motor used in, for example, a blower drive motor for an air conditioner or a water heater, a disk drive motor for an office automation equipment such as a personal computer or a word processor. It relates to the device.

[0002]

2. Description of the Related Art Conventionally, as a drive control device for a brushless DC motor of this type, for example, Japanese Patent Laid-Open No. 5-137375.
The one disclosed in Japanese Patent Publication is known. That is, as shown in FIG. 23, after the AC voltage E supplied from the commercial AC power supply 11 is converted into the DC voltage V by the rectifying / smoothing circuit 12, the DC voltage V is stepped down by the stepping switching power supply 13 by chopping. , This stepped down DC voltage V
It is configured to supply M to the drive control circuit 14.

A switching power element TR in which the step-down switching power supply 13 is composed of a power transistor
And a smoothing circuit 33 including a smoothing diode D1, a smoothing coil L and a smoothing capacitor C2. The signal from the rotor position detector 8 is logically processed by the commutation signal generation circuit 29, and the output signal is input to the switching power element drive circuit 28 to switch the energization switching circuit 23 composed of a plurality of switching power elements. Of the DC power source, the stepped DC voltage VM is supplied from the switching power source 13 to the armature coil 7 of each phase of the DC motor M by the ON / OFF operation of the switching power elements to sequentially energize the armature coil 7, and the rotor of the DC motor M is rotated. Rotate the assembly.

When the DC motor M is rotated, the speed error signal generation circuit 30 compares the rotation speed command signal b from the outside with the rotation speed signal c from the speed sensor 31 to generate a speed error signal d, The speed error signal d is input to the pulse width modulation (PWM) circuit 32 to generate a high frequency PWM signal d with ON / OFF duty according to the error between the signals b and c, and the PWM signal d is used to generate the high frequency PWM signal d. The switching power element is intermittently turned on / off to control the DC motor M at a variable speed.

[0005]

By the way, the drive control device for a DC motor having the above-mentioned structure has problems that the accuracy of the rotation speed of the motor is low, motor noise, deterioration of motor drive efficiency, and torque unevenness occur.

The present invention has been made in order to solve the above problems, and improves the accuracy of the number of revolutions of a motor to prevent noise from being generated in the motor, and also prevents deterioration of motor driving efficiency and uneven torque, which is small and inexpensive. It is an object of the present invention to provide a drive control device for a simple brushless DC motor.

[0007]

In order to achieve the above object, a drive controller for a brushless DC motor according to a first aspect of the present invention comprises a rotor assembly in which a rotor magnet is mounted on a rotor yoke fixed to a rotary shaft. A stator assembly in which a plurality of armature coils facing the rotor magnet are mounted on a stator yoke in a rotation direction, and a drive control circuit for sequentially energizing the armature coils to drive and control the rotation of the rotor assembly. The drive control circuit detects the magnetic pole distribution of the rotor magnet and outputs a rotor position detection signal, and holds the amplitude of each rotor position detection signal at a constant value. Auto gain control (AG
C) a circuit, and a phase shift circuit which outputs a plurality of shift signals having a phase difference of a predetermined electrical angle to the rotor position detection signal,
A reference signal oscillator for generating a first high-frequency reference signal composed of a triangular wave or a sawtooth wave having an audible frequency band or higher, and at least one of an amplitude and a center level of the first high-frequency reference signal being variably controlled. The reference signal variable circuit for generating the second high frequency reference signal is compared with one of the first and second high frequency reference signals and the transition signal, and the first pulse width modulation (PWM) signal is obtained from the difference between the two signals. A first comparator for outputting, a second comparator for comparing the other of the first and second high-frequency reference signals with the transition signal, and a second comparator for outputting a second PWM signal from the difference between the two signals, An energization switching circuit that receives the first and second PWM signals and energizes the corresponding amateur coil of each phase is provided.

According to a second aspect of the present invention, there is provided a drive control device for a brushless DC motor, wherein the drive control circuit detects a magnetic pole distribution of the rotor magnet and outputs a rotor position detection signal, and the rotor position detector. An automatic gain control (AGC) circuit for holding the amplitude of the rotor position detection signal at a constant value, a plurality of transition signals having a phase difference of a predetermined electrical angle with respect to the rotor position detection signal, and this transition signal 180
A phase shift circuit that outputs an inverted signal with a phase difference of °,
A first comparator that outputs a polarity determination signal that determines the magnetic pole of the rotor magnet by comparing the transition signal with an inversion signal, and a full wave that full-wave rectifies the transition signal and outputs a full-wave rectified signal. A rectifier, a reference signal oscillator that generates a high-frequency reference signal composed of a triangular wave or a sawtooth wave in the audible frequency band, a high-frequency reference signal, and a full-wave rectified signal are compared, and pulse width modulation is performed based on the difference between the two signals. A second comparator that outputs a (PWM) signal, a logic circuit that logically processes the polarity determination signal and the PWM signal and outputs a logical sum signal of both signals, and each corresponding to receive the logical sum signal. An energization switching circuit for energizing the phase amateur coil is provided.

According to a third aspect of the present invention, there is provided a brushless DC motor drive control device, wherein a drive control circuit detects a magnetic pole distribution of the rotor magnet and outputs a rotor position detection signal, and the rotor position detector. Automatic gain control (AG to keep the amplitude of rotor position detection signal at a constant value)
C) circuit, and a phase shift circuit for outputting a plurality of shift signals having a phase difference of a predetermined electrical angle with respect to the rotor position detection signal and an inversion signal having a phase difference of 180 ° with respect to the shift signals. And a first comparator for comparing the shift signal with the inverted signal to output a polarity discriminating signal for discriminating the magnetic pole of the rotor magnet, and full-wave rectifying the shift signal to output a full-wave rectified signal. A full-wave rectifier, a reference signal oscillator that generates a high-frequency reference signal composed of a triangular wave or a sawtooth wave in the audible frequency band, a high-frequency reference signal and a full-wave rectified signal are compared, and a pulse is generated from the difference between the two signals. A second comparator that outputs a width modulation (PWM) signal, the polarity determination signal, and the PW
A logic circuit for logically processing the M signal and outputting a logical sum signal of both signals, and an energization switching circuit for receiving the logical sum signal and energizing the corresponding amateur coil of each phase are provided. .

According to another aspect of the present invention, there is provided a drive control device for a brushless DC motor, wherein a drive control circuit detects a magnetic pole distribution of a rotor magnet and outputs a sinusoidal rotor position detection signal. , An automatic gain control (AGC) circuit that holds the amplitude of the rotor position detection signal at a constant value, and a rotor of another phase that is advanced in phase from the relevant phase.
A waveform correction circuit that cuts out a part of the signal position detection signal and adds it after multiplying the phase by a constant, a full-wave rectifier that full-wave rectifies the output signal of this waveform correction circuit and outputs a full-wave rectified signal, and the above-mentioned transition A first signal that compares a signal and an inverted signal and outputs a polarity determination signal that determines the magnetic pole of the rotor magnet
Comparator, a reference signal oscillator for generating a high frequency reference signal consisting of a triangular wave or a sawtooth wave in the audible frequency band, the full wave rectified signal and the high frequency reference signal are compared, and a pulse is generated from the difference between the two signals. A second comparator that outputs a width modulation (PWM) signal, a logic circuit that logically processes the polarity determination signal and the PWM signal and outputs a logical sum signal of both signals, and receives the logical sum signal to correspond And an energization switching circuit for energizing the amateur coil of each phase.

A brushless DC motor drive controller according to a fifth aspect of the present invention is characterized in that the constant to be multiplied in the waveform correction circuit is changed in proportion to the motor current. A brushless DC motor drive control device according to a sixth aspect of the present invention is characterized in that a constant to be multiplied in the waveform correction circuit is changed in proportion to the rotation speed of the motor.

According to a seventh aspect of the present invention, there is provided a drive control device for a brushless DC motor, in which a drive control circuit detects a magnetic pole distribution of a rotor magnet and outputs a rotor position detection signal, and a rotor position detector. Automatic gain control (AGC) that holds the amplitude of the rotor position detection signal at a constant value
A circuit, a full-wave rectifier that full-wave rectifies the rotor position detection signal and outputs a full-wave rectified signal, and compares the rotor position detection signal and the inverted signal to determine the magnetic pole of the rotor magnet. A first comparator that outputs a polarity determination signal, a reference signal oscillator that generates a high-frequency reference signal composed of a triangular wave or a sawtooth wave in the audible frequency band, and a full-wave rectified signal and a high-frequency reference signal. A second comparator for comparing and outputting a pulse width modulation (PWM) signal from the difference between the two signals;
A logic circuit that logically processes the polarity determination signal and the PWM signal and outputs a logical sum signal of both signals; and an energization switching circuit that receives the logical sum signal and energizes the corresponding amateur coil of each phase, The magnetic pole distribution of the rotor magnet facing the amateur coil is uniformly magnetized in the circumferential direction, and the magnetic pole distribution of the rotor magnet facing the rotor position detector is magnetized in the circumferential direction. It is characterized by

According to another aspect of the present invention, there is provided a drive control device for a brushless DC motor, wherein a drive control circuit detects a magnetic pole distribution of a rotor magnet and outputs a rotor position detection signal, and a rotor position detector. Automatic gain control (AGC) that holds the amplitude of the rotor position detection signal at a constant value
A circuit, a full-wave rectifier that full-wave rectifies the rotor position detection signal and outputs a full-wave rectified signal, and compares the rotor position detection signal and the inverted signal to determine the magnetic pole of the rotor magnet. A first comparator that outputs a polarity determination signal, a reference signal oscillator that generates a high-frequency reference signal composed of a triangular wave or a sawtooth wave in the audible frequency band, and a full-wave rectified signal and a high-frequency reference signal. A second comparator for comparing and outputting a pulse width modulation (PWM) signal from the difference between the two signals;
A logic circuit that logically processes the polarity determination signal and the PWM signal and outputs a logical sum signal of both signals; and an energization switching circuit that receives the logical sum signal and energizes the corresponding amateur coil of each phase, The rotor magnet facing the amateur coil and the rotor position detector is characterized in that it is formed in an uneven shape in the circumferential direction.

In the drive controller for the brushless DC motor according to the present invention, the number of rotor position detectors set is one less than the number of phases of the amateur coil, and the rotor position detection of this missing phase is performed. The signal is characterized in that it is synthesized by differentially amplifying the rotor position detection signals from the rotor position detectors of the other phases.

According to a tenth aspect of the present invention, in the drive controller for the brushless DC motor, the rotor position detector comprises means for detecting an induced electromotive voltage generated in the armature coil as the rotor assembly rotates. To do.

[0016]

According to the first aspect of the present invention, since the two high frequency reference signals having different center levels are used, the characteristics of the switching power element on the positive side and the switching power element on the negative side in the energization switching circuit are different. In this case, by optimizing the center level 0 of both the signals, the characteristic difference between the switching power elements is eliminated, the rotational speed accuracy of the motor is further improved, and the deterioration of the motor driving efficiency and the torque unevenness are prevented. In addition, it is possible to effectively prevent the noise generation of the motor.

According to the second aspect of the present invention, since one high frequency reference signal is used, the drive control circuit is simplified and the polarity discriminating signal from the logic circuit is used to detect each phase in the energization switching circuit. It is possible to prevent the positive side switching power element and the negative side switching power element from turning on or off at the same time, and effectively prevent short-circuit breakdown of these switching power elements.

According to the third aspect of the present invention, the shift signal from the phase shift circuit is full-wave rectified by the full-wave rectifier, and the full-wave rectified signal rising from 0% is compared with the high-frequency reference signal.
It is possible to make the minimum value of the pulse width of the ON / OFF duty in the PWM signal from the second comparator to be almost 0%, and therefore the rising characteristic of the energizing current at the time of starting energizing each amateur coil is slow. Thus, the noise generation of the motor can be further reduced.

According to the fourth aspect of the present invention, the voltage waveform applied to the amateur coil of each phase is larger than that of a simple sine wave in a predetermined electrical angle section at the start of commutation, and a large current is applied. The waveform can be approximated to a sine wave, and a sharp increase in current at the time of reversal of the current direction can be suppressed to effectively prevent the generation of vibration noise. Further, according to the above configuration, since the energizing current is directly controlled while the DC voltage applied to the amateur coil of each phase is maintained at a constant value, the energizing current is indirectly controlled by controlling the DC voltage. In comparison with the control method described above, the rotational speed accuracy can be improved, and the step-down switching power supply can be omitted, so that the cost and the size can be reduced.

According to the fifth aspect of the present invention, the current waveform is approximated to a sine wave with a large correction amount when the motor current is large, and with a small correction amount when the motor current is small, thereby suppressing a sharp increase in the current at the time of reversing the current direction. Then, the current waveform can be approximated to a sine wave with a correction amount according to the magnitude of the motor current, and a sharp increase in the current at the time of reversing the current direction can be suppressed, and the generation of vibration noise can be accurately prevented.

According to the sixth aspect of the invention, the current waveform is approximated to a sine wave with a small correction amount when the motor speed is fast and with a large correction amount when the motor speed is slow, and a sharp increase in the current at the time of reversing the current direction is suppressed. Then, the current waveform is approximated to a sine wave with a correction amount according to the magnitude of the motor speed,
It is possible to suppress a sharp increase in current at the time of reversing the current direction, and to prevent vibration noise from occurring accurately.

According to the invention of claim 7, the magnetic pole distribution of the rotor magnet facing the amateur coil is uniformly magnetized in the circumferential direction, and the magnetic pole distribution of the rotor magnet facing the rotor position detector is equal to the magnetic pole distribution. The voltage waveform applied to the armature coil of each phase inhomogeneously magnetized in the circumferential direction is larger than that of a simple sine wave, and a large voltage is applied in the section of a predetermined electrical angle at the start of commutation, resulting in a current waveform. It can approach a sine wave. In that case, since the detection signal from the rotor position detector is a correction signal that is not a sine wave, the phase shift circuit can be omitted and the circuit configuration can be simplified.

According to the eighth aspect of the present invention, the rotor magnet facing the amateur coil and the rotor position detector is formed in the circumferential direction in a concavo-convex shape so as to have substantially the same action as that described above. Can play. According to the invention of claim 9, the set number of the rotor position detector is made smaller than the number of phases of the amateur coil by one, and the rotor position detection signal of this missing phase is the rotor position of the other phase. The circuit configuration can be further simplified by differentially amplifying and combining the rotor position detection signals from the detector. Claim 1
According to the invention of No. 0, by configuring the rotor position detector by means for detecting the induced electromotive voltage generated in the armature coil with the rotation of the rotor assembly,
It is possible to achieve simplification of the circuit configuration.

[0024]

Embodiments of the present invention will be described below with reference to the drawings. Embodiment 1 FIG. 1 is a half-cut vertical sectional view showing the structure of a three-phase axial type brushless DC motor according to the present invention, and FIG. 2 is a partially cutaway plan view of the same DC motor. In FIG. 1, a DC motor M is composed of a rotor assembly A and a stator assembly B. In the rotor assembly A, a rotor magnet 2 is fixed to a lower surface of a rotor yoke 1, and a rotary shaft 3 is mounted on a bearing housing via a radial bearing 5. 6 is rotatably supported, and the stator assembly B is arranged on the upper surface of the stator yoke 4 so as to face the rotor magnet 2 and has the U-phase and V-phase shown in FIG.
U-phase three-phase amateur coils 7 (7U, 7V, 7W) are fixed in the circumferential direction (direction of arrow a) to detect the magnetic flux distribution of the rotor magnet 2 and to detect the magnetic pole position.
It is configured by setting rotor position detectors 8 (8U, 8V, 8W) for phase, V phase, and W phase.

In order to effectively generate a torque in the circumferential direction, the armature coil 7 has an outer shape formed in a spiral shape along a line segment substantially parallel to the radiation x from the center of rotation O. The position detector 8 (8U, 8V, 8W) is set on the center line x1 of the armature coil 7 in order to detect the magnetic pole position of the rotor magnet 2, and the rotor magnet 2 is set as shown in FIG. , Magnetization distribution is N pole part 2
The n and S pole portions 2s are magnetized by alternately arranging them in the circumferential direction along the radiation x2 from the center of rotation O alternately in the circumferential direction, and the currents I (IU, IV, IW) are sequentially applied to the respective amateur coils 7. Then, as shown in FIG. 4, the magnetic flux Φ (Φn, Φs) generated between the rotor magnet 2 and the stator yoke 4 and the current I are interlinked, and rotation is performed based on Fleming's left-hand rule. The rotor assembly A is configured to rotate normally (in the direction of arrow a1) by generating a force.

FIG. 5 is a block diagram showing a drive control device for a DC motor according to the present invention. In the figure, 11 is a commercial AC power supply, 12 is a rectifying / smoothing circuit for converting an AC voltage E supplied from the commercial AC power supply 11 into a DC voltage V, and this rectifying / smoothing circuit 12 is a diode bridge circuit D and a smoothing capacitor. It is composed of C1. 13 is a step-down switching power supply, and this step-down switching power supply 1
3 includes a switching power element TR including a power transistor, and a smoothing circuit 33 including a smoothing diode D1, a smoothing coil L and a smoothing capacitor C2.

The signal from the rotor position detector 8 is logically processed by the commutation signal generation circuit 29, and the output signal is input to the switching power element drive circuit 28, and the energization switching circuit composed of a plurality of switching power elements. 23 is commutated, and the step-down DC voltage VM from the switching power supply 13 is supplied to the armature coils 7 of each phase of the DC motor M by the ON / OFF operation of each switching power element so that the DC motor M is sequentially energized. Rotate M rotor assembly. Rotor position detector 8 (8U, 8V, 8W)
Is composed of, for example, a hall element, and represents the magnetic pole positions of the N pole portion 2n and the S pole portion 2s of the rotor magnet 2 in FIG. Output signals HUU, HVU, HWU of the positive pole which are the detection signals of the N pole portion 2n in the phase, V phase and W phase, and an output signal HU of the negative pole which is the detection signal of the S pole portion 2s in each phase.
Since L, HVL, and HWL are output and there are three phases for one cycle (electrical angle of 360 °) of the sinusoidal pattern, the phase difference of the output signals in each phase is 360 ° / 3 = 120 °.

Reference numeral 16 is a differential amplifier.
Is the difference between the positive and negative output signals for each phase in the output signal H (HU, HV, HW) from the rotor position detector 8 (8U, 8V, 8W). The in-phase noise component superimposed on is removed. Reference numeral 17 denotes a phase shift circuit composed of, for example, a differential amplifier.
Are output signals H from the differential amplifier 16 shown in FIG.
Difference signals of (HU, HV, HW) (HU-HV, HV-HW, HW-
HU, HV-HU, HW-HV, HU-HW), the shift signal H1 (HU1, with a phase difference Δθ of 30 °, for example,
HV1, HW1) are output. Reference numeral 27 is an automatic gain control circuit (AGC circuit). In this AGC circuit 27, for example, a rotor position detector 8 (8U, 8V, 8W) consisting of a Hall element is used for U phase, V phase, Output signals HUU, HVU, HW in W phase
The fluctuations of the amplitudes of U, HUL, HVL and HWL are made constant.

Reference numeral 21 is a reference signal oscillator which generates a first high frequency reference signal e1 consisting of a triangular wave or a sawtooth wave having an audible frequency band (16 kHz) or more. A reference signal variable circuit 26 variably controls at least one of the amplitude and center level of the first high frequency reference signal e1 to generate the second high frequency reference signal e2. . Reference numeral 18 denotes a first comparator which receives the shift signal H1 (HU1, HV1, HW1) from the phase shift circuit 17 and the second high frequency reference signal e2 from the reference signal variable circuit 26. For each phase, the PWM signal HUPWM (HUUPWM, HVUPWM, HWU) which is the drive signal of the positive electrode (N pole) in the U phase, V phase, and W phase is compared.
It is configured to output (PWM).

Reference numeral 20 is a second comparator, and this comparator 20
Is a shift signal H1 (HU1, HV1,
HW1) and the first high-frequency reference signal e1 from the reference signal oscillator 21 are compared for each phase, and the PWM signal HLPWM (H that is the drive signal of the negative pole (S pole) in each phase is compared.
ULPWM, HVLPWM, HWLPWM). 23 is an energization switching circuit. This energization switching circuit 23
For example, it is composed of switching power elements TRU1, TRV1, TRW1 composed of power transistors which are ON-operated at the positive poles (N poles) of the U-phase, V-phase and W-phase, and power transistors which are ON-operated at the negative poles (S-pole) of each phase. The switching power elements TRU2, TRV2, TRW2 are provided, and the switching power elements TRU1, TRV1, TRW1 are turned on by the positive electrodes of the respective phases via the switching transistors TRU3, TRV3, TRW3, and the switching power elements TRU1 to TRW2 is the amateur coil 7 (7
U, 7V, 7W) is applied with the DC voltage VM from the step-down switching DC power supply 13 to sequentially energize.

Next, the operation of the above configuration will be described. The AC voltage E supplied from the commercial power supply 11 is the rectifying / smoothing circuit 1
After being converted into the DC voltage V in step 2, the stepped down DC power supply VM from the step-down switching power supply 13 is applied to the drive control circuit 14. On the other hand, the rotor position detector 8 (8U, 8
After the noise component is removed by the differential amplifier 16 from the signal from V, 8W), the three-phase output signal H (HU, HV, HW) shown by the dotted line in FIG. 6 is output from the differential amplifier 16. . These output signals H (HU, HV, HW) are output from the differential amplifier 16 in the phase shift circuit 17 as difference signals (HU-HV, HV-HW, HW-) of the output signals H (HU, HV, HW). HU, HV-HU, HW-HV, HU-HW)
And the transition signals H1 (HU1, HV1, H shown by the solid line in FIG. 6 are obtained.
W1) is output.

The shift signal H1 (HU from the phase shift circuit 17)
1, HV1, HW1) and the second high-frequency reference signal e2 from the reference signal variable circuit 26 are compared for each phase by the first comparator 18, and the energization switching circuit 23 for each phase is compared. PWM signal HUPWM (HUUPWM, HVU) driven by the positive pole (N pole)
PWM, HWUPWM) is output. Further, the shift signal H1 (HU1, HV1, HW1) from the phase shift circuit 17 and the first high frequency reference signal e1 from the reference signal oscillator 21 are compared by the second comparator 20 for each phase. The energization switching circuit 23
PWM signal HLPWM (H that drives the negative polarity (S pole) of each phase
Outputs ULPWM, HVLPWM, HWLPWM). That is, the U-phase, V-phase, and W-phase switching power elements TRU1, TRV1, TRW1 in the energization switching circuit 23 are connected to the PW via the switching transistors TRU3, TRV3, TRW3.
The M signal HUPWM (HUUPWM, HVUPWM, HWUPWM) is input and ON operation is performed at the positive electrode of each phase, and the DC voltage VM from the step-down switching power supply 13 corresponds to the amateur coil 7 (7U, 7V, 7W) of each phase. Apply to. Further, the U-phase, V-phase, and W-phase switching power elements TRU2, TRV2, TRW2 in the energization switching circuit 23 are supplied with the PWM signal HLP.
WM (HULPWM, HVLPWM, HWLPWM) is input and ON operation is performed at the negative electrode of each phase, and the DC voltage VM from the step-down DC power supply 13 is applied to the amateur coil 7 (7U, 7V, 7W) of each phase. The rotor assembly A shown in FIGS. 1 and 2 is rotated normally (in the direction of arrow a1) by sequentially energizing.

According to the above configuration, in order to use the first and second high frequency reference signals e1 and e2 having different center levels 0, the positive side of the U phase, V phase and W phase in the energization switching circuit 23 is used. Switching power element TRU1, TRV1, T
RW1 and switching power devices TRU2, TR on the negative side
Even when the characteristics of V2 and TRW2 are different, both signals e1,
By optimizing the central level 0 of e2, the characteristic difference between the switching power elements TRU1 to TRW2 can be eliminated, and the motor speed can be controlled with high accuracy, so that the motor M can be controlled.
The rotational speed accuracy of can be improved.

By the way, in the above configuration, for example, a command signal (not shown) from the central processing unit 25 is input to the reference signal oscillator 21 and the reference signal variable circuit 26, and the first and second high frequency references shown in FIG. Amplitudes h and h1 of signals e1 and e2 and height G of center level 0 are variably controlled, and a PWM signal HUPWM is a comparison signal with reference signals e1 and e2.
(HUUPWM, HVUPWM, HWUPWM) and HLPWM (HULPWM, HVLPW
The pulse width of ON / OFF duty in (M, HWLPWM) may be expanded or reduced to control the motor speed. Now, for example, when the motor speed is faster than a predetermined value, a command signal for increasing the amplitudes h, h1 of the high frequency reference signals e1, e2 and the height level G is input to the oscillator 21 and the reference signal variable circuit 26. Therefore, the PWM
Signals HUPWM (HUUPWM, HVUPWM, HWUPWM) and HLPWM (HUL
It is possible to reduce the motor speed by reducing the pulse width of ON / OFF duty in PWM, HVLPWM, HWLPWM).

Further, in the above structure, the signal from the rotor position detector 8 is received and the amateur coil 7 (7U, 7V,
After applying voltage to 7W), the actual current I (IU, IV, I
The amateur coil 7 (7U, 7)
A delay corresponding to the time constant occurs due to the inductance component of (V, 7W), and the commutation timing of the current I flowing through the amateur coil 7 is delayed from the regular commutation timing, which deteriorates the motor drive efficiency and increases torque unevenness. To do. However, as shown in FIG. 6, the commutation timing of the current I flowing through the amateur coil 7 is expected to be delayed by a predetermined electrical angle from the regular commutation timing, and corresponds to the electrical angle.
For example, the shift signal H1 (HU1,
HV1, HW1) is output from the phase shift circuit 17, and the current I
By advancing or delaying the commutation timing of, the optimum electrical angle control can be easily achieved not only when the rotor assembly A is normally rotated (direction of arrow a1) but also when it is reversed (direction of arrow a2). The electrical angle control can be achieved with the rotor position detectors 8 set on the center line x1 of the amateur coil 7, and the rotor position detectors 8 can be easily set. Moreover, the current I (IU, IV, I) flowing through each of the above amateur coils 7 (7U, 7V, 7W)
The commutation timing of (W) is corrected to a regular commutation timing, and the mechanical displacement error between the armature coil 7 and the rotor position detector 8 is easily and electrically corrected to reduce the motor drive efficiency. Torque unevenness can be effectively prevented.

Further, according to the above configuration, the acceleration / deceleration of the motor is controlled by the HUPWM (HUUPWM, HVUPW) from the comparators 18, 20.
M, HWUPWM) and HLPWM (HULPWM, HVLPWM, HWLPWM) are performed by expanding and contracting the pulse width of ON / OFF duty, and the pulse width of the above PWM signal is compared with the high frequency reference signals e1 and e2 of the triangular wave. In order to be caused by
It is possible to slow the rise and fall of the energizing current I (IU, IV, IW) at the start and end of energization of each of the amateur coils 7 (7U, 7V, 7W). Therefore, when the armature coil 7 (7U, 7V, 7W) of each phase is energized and disconnected, there is no generation of abruptly changing electromagnetic force, and a strong vibration impact force is applied to the rotor assembly A of the motor M. Since there is no possibility of being urged, it is possible to effectively prevent noise generation of the motor.

Embodiment 2 FIG. 7 is a block diagram showing another example of the drive control device for the DC motor according to the present invention.
In the figure, the phase shift circuit 17 has a mutual difference signal (HU-HV, H) between the output signals H (HU, HV, HW) from the differential amplifier 16.
HV-HW, HW-HU, HV-HU, HW-HV, HU-HW), the transition signal H1 (HU1, HV1, HW1) having a phase difference Δθ of, for example, 30 ° is obtained as shown in FIG. ) And an inverted signal H2 (HU2, HV2, HW2) whose phase is 180 ° out of phase with the transition signal H1 (HU1, HV1, HW1).

The first comparator 18 receives the shift signal H1 (HU1, HV1, HW1) from the phase shift circuit 17 and the inverted signal H2 (HU.
2, HV2, HW2) for each phase, U phase, V phase,
Polarity discrimination signal HHL (HUHL, VVHL, WWHL) in W phase,
That is, HUHL (HU1-HU2), HVHL (HV1-HV2), HWHL
It is configured to output (HW1-HW2). Second
Of the shift signal H1 (H1
U1, HV1, HW1) and the high frequency reference signal e of the triangular wave or sawtooth wave of the audible frequency band (16 kHz) or more from the oscillator 21, and receives the transition signal H1 (HU1, HV1, HW1).
And the high-frequency reference signal e are compared, and both signals e, H1
The PWM signal HPWM (HUPWM, HVPWM, HWPWM) is output from the difference between the two.

22 (22U, 22V, 22W) are U phase, V phase,
Each of the logic circuits 22 is a W-phase logic circuit, and
Polarity discrimination signal HHL (HUHL, VVHL, W from the comparator 18 of
WHL) and the PWM signal HPWM (HUP from the second comparator 20)
WM, HVPWM, HWPWM) for each phase, and the logical sum (OR) signal of both signals HHL, HPWM, that is, U phase,
Positive (N pole) PWM signal HU1 (H in V phase and W phase
UU1, HVU1, HWU1) to the energization switching circuit 23 of the DC motor M
In addition to the above, the negative polarity (S pole) PWM signals HL1 (HUL1, HVL1, HWL1) in each phase are input to the energization switching circuit 23. Since other configurations are almost the same as those in the above-described first embodiment, the same or corresponding portions as those in FIG. 5 are denoted by the same reference numerals and detailed description thereof will be omitted.

Next, the operation of the above configuration will be described. Figure 7
In the phase shift circuit 17 shown in FIG.
Difference signal (HU-HV, HV-HW, HW-HU, HV-HU, HW-HV, HU-HW) of the three-phase output signal H (HU, HV, HW) shown by the dotted line
And the transition signals H1 (HU1, HV1, H shown by the solid line in FIG. 8 are obtained.
W1) and this transition signal H1 (HU1, HV1, HW1)
Inverted signal H2 (H
U2, HV2, HW2) are output.

The shift signal H1 (HU from the phase shift circuit 17)
1, HV1, HW1) and inverted signal H2 (HU2, HV2, HW2)
Is compared by the first comparator 18 for each phase, and each polarity determination signal HHL (HUHL, VVHL, WWHL), that is, H
UHL (HU1-HU2), HVHL (HV1-HV2), HWHL (HW1- HW2)
Is output. These polarity discrimination signals HHL (HUHL, VV
HL, WWHL) are switching power elements TRU1, TRV1, TRW1 on the positive side of each phase in the energization switching circuit 23,
Negative side switching power devices TRU2, TRV for each phase
It becomes an information signal indicating which of TR2 and TRW2 is turned on.

The shift signal H from the phase shift circuit 17 is also used.
1 (HU1, HV1, HW1) and the triangular high-frequency reference signal e shown by the solid line in FIG. 8 above the audible frequency band (16 kHz) from the oscillator 21 are output by the second comparator 20 for each phase. The PWM signals HPWM (HUPWM, HVPWM, HWPWM) shown in FIG. 8 are compared from the difference between these two signals e, H1 (HU1, HV1, HW1).
Is output.

The above PWM signals HPWM (HUPWM, HVPWM, H
WPWM) is compared with the polarity discrimination signal HHL (HUHL, VVHL, WWHL) in the logic circuit 22 (22U, 22V, 22W) for each phase, and the logical sum (AND) signal of both signals HHL, HPWM, that is, U The positive polarity (N pole) PWM signals HU1 (HUU1, HVU1, HWU1) in the V, V, and W phases are input to the energization switching circuit 23 of the DC motor M, and the negative polarity (S pole) PWM signals in each of the above phases are input. HL1 (HUL1, HVL1, HWL1) is input to the energization switching circuit 23, the switching power elements TRU1 and TRW2 of each phase are turned on and off, and the DC voltage VM from the step-down DC power supply 13 is supplied to the amateur coil 7 of each phase. (7U, 7V, 7W) is applied and sequentially energized.
And the rotor assembly A shown in FIG.
1 direction).

According to the above construction, since one high-frequency reference signal e is used, the drive control circuit 14 is simplified and the polarity discrimination signal HHL (HUHL) from the logic circuit 22 (22U, 22V, 22W) is used. , VVHL, WWHL) to prevent the positive-side switching power elements TRU1, TRV1, TRW1 of each phase and the negative-side switching power elements TRU2, TRV2, TRW2 of the energization switching circuit 23 from being simultaneously turned ON, Each of these switching power devices TR
It is possible to effectively prevent short circuit breakdown of U1 to TRW2.

[Embodiment 3] FIG. 9 is a block diagram showing another example of a drive control device for a DC motor according to the present invention. Reference numeral 19 denotes a full-wave rectifier. The full-wave rectifier 19 full-wave rectifies the shift signal H1 (HU1, HV1, HW1) from the phase shift circuit 17 to generate a full-wave rectified signal H3 (HU3, HV3, HW3). It is configured to output. The second comparator 20 receives the full-wave rectified signal H3 (HU3, HV3,
HW3) and a high frequency reference signal e of a triangular wave or a sawtooth wave having an audible frequency band (16 kHz) or more from the oscillator 21, and receives the full wave rectified signal H3 (HU3, HV3, HW3) and the high frequency reference signal. e, and a PWM signal HPWM (HUPWM, HVPWM, HWPWM) is output from the difference between the two signals e and H3. Since other configurations are substantially the same as those in the above-described second embodiment, the same or corresponding portions as those in FIG. 7 are denoted by the same reference numerals and detailed description thereof will be omitted.

Next, the operation of the above configuration will be described. Figure 9
, The shift signal H1 from the phase shift circuit 17 (HU1, HV
1, HW1) and the inverted signal H2 (HU2, HV2, HW2)
The first comparator 18 makes a comparison for each phase, and each polarity determination signal HHL (HUHL, VVHL, WWHL), that is, HUHL (H
U1-HU2), HVHL (HV1-HV2), and HWHL (HW1-HW2) are output. Each of these polarity discrimination signals HHL (HUHL, VVHL, W
WHL) is the switching power elements TRU1, TRV1, TRW1 on the positive side of each phase and the switching power elements TRU2, TRV2, TR on the negative side of each phase in the energization switching circuit 23.
This is an information signal indicating which of W2 is turned on.

Further, the shift signal H from the phase shift circuit 17
1 (HU1, HV1, HW1) is full-wave rectified by the full-wave rectifier 19 and a full-wave rectified signal H3 (HU3, HV3, HW3) is output.
As an example of the full-wave rectified signal H3 (HU3, HV3, HW3), the U-phase full-wave rectified signal HU3 is shown in FIG. The full-wave rectified signal H3 (HU3, HV3, HW3) is the second
In the comparator 20, the audible frequency band from the oscillator 21 (16kH
z) Compared with the triangular wave high frequency reference signal e, the PWM signal HPWM (HUPWM, HVPWM, HWPWM) shown in FIG. 10 is output from the difference between these two signals e, H3 (HU3, HV3, HW3). It

The above PWM signals HPWM (HUPWM, HVPWM, H
WPWM) is compared with the polarity discrimination signal HHL (HUHL, VVHL, WWHL) in the logic circuit 22 (22U, 22V, 22W) for each phase, and the logical sum (AND) signal of both signals HHL, HPWM, that is, U Of the positive polarity (N pole) PWM signals HUU1, HVU1 and HWU1 in the three-phase, V-phase and W-phase to the energization switching circuit 2 of the DC motor M.
3 and the negative electrode (S pole) in each phase
The PWM signals HUL1, HVL1 and HWL1 of
3 to input switching power elements TRU1 to
TRW2 is turned on and off, and the step-down DC power supply 13
Direct current voltage VM from the armature coil 7 (7U,
7V, 7W) and sequentially energized to rotate the rotor assembly A shown in FIGS. 1 and 2 forward (in the direction of arrow a1).

According to the above construction, since one high-frequency reference signal e is used, the drive control circuit 14 is simplified, and the polarity discrimination signal HHL (HUHL) from the logic circuit 22 (22U, 22V, 22W) is used. , VVHL, WWHL) to prevent the positive-side switching power elements TRU1, TRV1, TRW1 of each phase and the negative-side switching power elements TRU2, TRV2, TRW2 of the energization switching circuit 23 from being simultaneously turned ON, Each of these switching power devices TR
It is possible to effectively prevent short circuit breakdown of U1 to TRW2.

In the second embodiment, the PWM signal HPWM (HUPWM, HUPWM, shown in FIG. 8 from the second comparator 20 is used.
HVPWM, HWPWM) has a minimum ON / OFF duty pulse width of 50%, while this embodiment 3
, The full-wave rectified signal H3 (HU3, H
By using V3, HW3), the PWM shown in FIG.
ON / O in signal HPWM (HUPWM, HVPWM, HWPWM)
It is possible to make the minimum value of the pulse width of the FF duty almost 0%. Therefore, the energizing current I at the start of energizing each of the amateur coils 7 (7U, 7V, 7W)
The rise characteristics of (IU, IV, IW) can be made slower to further reduce the noise generation of the motor.

Fourth Embodiment FIG. 11 is a block diagram showing still another example of the drive control device for the DC motor according to the present invention. Reference numeral 50 denotes a correction circuit.
Is, for example, as shown in Figure 12,
lusive) NOR circuit 51, analog switch 52, amplifier 53, and adder 54. Now, in the NOR circuit 51, for example, the exclusive OR (NOR) of the shift signals HU1 and HV1 from the phase shift circuit 17 is taken, and both the shift signals HU1 and HV1 are pulsed at a large portion or a small portion. , And outputs the pulse signal Ha shown in FIG.

Next, the pulse signal Ha and the transition signal H
The logical product (AND) with V1 is taken and the analog switch 52
13 outputs the high-order portion of the pulse signal Ha from the transition signal HV1 and further outputs the correction pulse signal Hb shown in FIG. 13 multiplied by the correction coefficient (constant) in the amplifier 53, and the adder 54 outputs the pulse. By adding the correction pulse signal Hb to the signal Ha, the transition signal H
The correction signal HcU of U1 is output. The correction signals HcV and HCW of the other shift signals HV1 and HW1 are also output in substantially the same manner. Correction signal Hc (HcU, HcV, HCW)
Is full-wave rectified by the full-wave rectifier 19 and the full-wave rectified signal H3 (H
U3, HV3, HW3) is output, the signal processing disclosed in the third embodiment is performed, and a DC voltage VM is applied to the amateur coils 7 (7U, 7V, 7W) of each phase to sequentially energize them. 1
And the rotor assembly A shown in FIG.
1 direction).

According to the above configuration, the voltage waveform applied to the amateur coil 7 (7U, 7V, 7W) of each phase is larger in the section of the electrical angle of 60 ° at the start of commutation than the simple sine wave. A voltage is applied and the current waveform can be approximated to a sine wave. That is, the amateur coil 7 (7U, 7
V, 7W) is applied with the DC voltage V shown in FIG.
(U, IV, IW), the current does not flow for some time T when the current direction is reversed, for example, in the section of the electrical angle of 60 ° after the current direction is reversed, and then the current I sharply increases and vibrates. It causes noise. On the other hand, according to the above configuration, the voltage waveform applied to the amateur coil 7 (7U, 7V, 7W) of each phase is compared with a simple sine wave, and in the section of the electrical angle of 60 ° at the start of commutation. A large voltage is applied by the correction circuit 50 so that the current waveform approaches a sine wave, and a sharp increase in the current I at the time of reversing the current direction can be suppressed to effectively prevent the generation of vibration noise.

Further, according to the above construction, the energizing current I (IU, IV, IW) of the armature coil 7 (7U, 7V, 7W) of each phase is maintained at a constant value. )
In order to directly control the current, as compared with the drive control devices in the above-described first to third embodiments, which directly controls the energizing current I (IU, IV, IW) by controlling the DC voltage VM. As a result, the motor speed can be controlled with higher accuracy, the rotational speed accuracy can be improved, the step-down switching power supply 13 can be omitted, and the number of parts can be reduced, and the cost and size can be reduced. is there.

Fifth Embodiment: FIG. 15 is a block diagram showing still another example of the drive control device for a DC motor according to the present invention. In the figure, 55 is a resistor R, for example.
The current detector 55 detects the motor current I and inputs the detection signal HR to the correction circuit 50 shown in FIG. 16 to make the amplification factor of the amplifier 53 variable in proportion to the external voltage. A large correction amount is obtained when the motor current I is large, and a small correction amount is obtained when the motor current I is small, so that the optimum motor current I can be compensated. Other configurations and operational effects are almost the same as those in the above-described fourth embodiment, and therefore, the same or corresponding portions as those in FIG. 11 are designated by the same reference numerals and detailed description thereof will be omitted.

Sixth Embodiment: FIG. 17 is a block diagram showing still another example of a drive control device for a DC motor according to the present invention. In this embodiment, the central processing unit 25 detects the current speed by counting the pulse train from the rotation speed detection circuit 24 every predetermined time, and corrects the voltage signal HP inversely proportional to the rotation speed shown in FIG. Inputting to the circuit 50, the amplification factor of the amplifier 53 is made variable in proportion to the external voltage, and a small correction amount is obtained when the motor speed is fast, and a large correction amount is obtained when the motor speed is slow to compensate the optimum motor current I. You can Other configurations and operational effects are almost the same as those in the above-described fourth embodiment, and therefore, the same or corresponding portions as those in FIG. 11 are designated by the same reference numerals and detailed description thereof will be omitted.

Embodiment 7: FIG. 18 is a plan view showing another example of the magnetization distribution of a rotor magnet applied to the drive control device for a DC motor according to the present invention. As shown in the figure, the rotor magnet 2 includes an amateur coil 7 (7U, 7U).
The N pole portion 2n and the S pole portion 2s facing V, 7W) are uniformly magnetized in the circumferential direction, and the N pole portion 2n1 and S facing the rotor position detector 8 (8U, 8V, 8W) are The pole portion 2s1 is non-uniformly magnetized in the circumferential direction, and the amateur coil 7 (7U, 7V, 7
The voltage induced in (W) has a sine wave characteristic as shown in FIG. 19 (A), while the rotor position detector 8 (8U, 8V, 8
The detection signal in (W) is, as shown in FIG. 19B, the correction pulse signal H in addition to the above-mentioned three-phase output signal H (HU, HV, HW).
It becomes the correction signal H4 (HU4, HV4, HW4) with b added.

According to the above configuration, the voltage waveform applied to the amateur coil 7 (7U, 7V, 7W) of each phase is compared with a simple sine wave, and a predetermined electrical angle at the start of commutation, for example, a section of 60 °. At, a large voltage is applied, and the current waveform can be approximated to a sine wave. That is, in the seventh embodiment, the three-phase output signal H (HU, HU, detected by the rotor position detector 8 (8U, 8V, 8W) instead of the above-mentioned correction circuit 50 is detected.
(HV, HW) is the correction signal H to which the correction pulse signal Hb is added
By setting 4 (HU4, HV4, HW4), it is possible to obtain substantially the same operational effect as the drive control circuit 14 using the correction circuit 50 described above. The DC motor drive controller according to the seventh embodiment is a rotor position detector 8 (8U, 8V, 8).
Correction signal H4 (HU4, H)
V4, HW4), the phase shift circuit 17 can be omitted as shown in FIG. 20 to simplify the circuit configuration. In the above-described configuration, the rotor magnet 2 has the N-pole portion 2n1 and the S-pole portion 2s1 whose cross section is formed in an uneven shape as shown in FIGS. 21 and 22, and the correction signal H4 (HU4, HV4, H
It may be configured to output a detection signal substantially similar to W4).

In each of the first to seventh embodiments described above, the set number of the rotor position detector 8 (8U, 8V, 8W) is set to the amateur coil 7
One less than the number of phases of (7U, 7V, 7W), and the rotor position detection signal of this missing phase is different from the rotor position detection signal from the rotor position detector of the other phase. By amplifying and synthesizing, the circuit configuration can be further simplified. Further, the rotor position detector 8 (8U, 8V, 8W) should be constructed by means for detecting the induced electromotive voltage generated in the amateur coil 7 (7U, 7V, 7W) accompanying the rotation of the rotor assembly A. Thus, simplification of the circuit configuration can be achieved.

[0060]

As described above, according to the first aspect of the present invention, by using two high frequency reference signals having different center levels, it is possible to eliminate the characteristic difference between the switching power elements and improve the rotational speed accuracy of the motor. It is possible to further improve the efficiency, prevent deterioration of the motor drive efficiency and torque unevenness, and effectively prevent noise generation of the motor. According to the invention of claim 2, the drive control circuit is simplified by one high frequency reference signal and the polarity discrimination signal, and the positive and negative side switching power elements of each phase in the energization switching circuit are simultaneously turned on or It is possible to avoid the OFF operation and effectively prevent the short-circuit breakdown of each of these switching power elements.

According to the third aspect of the invention, the full-wave rectified signal rising from 0% is compared with the high-frequency reference signal, and the PW
The minimum value of the pulse width of the ON / OFF duty in the M signal is set to almost 0%, the rising characteristic of the energizing current at the start of energizing each amateur coil is made slow, and the noise generation of the motor can be reduced. According to the invention of claim 4, a steep increase of the current at the time of reversing the current direction is suppressed to effectively prevent the generation of vibration noise, the rotational speed accuracy is improved, and the step-down switching power supply is omitted. It is cheap and can be miniaturized.

According to the fifth aspect of the present invention, the current waveform is approximated to a sine wave with a correction amount according to the magnitude of the motor current,
It is possible to suppress a sharp increase in current at the time of reversing the current direction, and to prevent vibration noise from occurring accurately. According to the invention of claim 6, the current waveform is approximated to a sine wave with a correction amount according to the magnitude of the motor speed, and a sharp increase of the current at the time of reversal of the current direction is suppressed to accurately generate vibration noise. Can be prevented.

According to the seventh and eighth aspects of the present invention, the voltage waveform applied to the amateur coil of each phase is compared with a simple sine wave, and a large voltage is applied in a predetermined electrical angle section at the start of commutation. The current waveform can be approximated to a sine wave to suppress a steep increase in the current when the current direction is reversed to properly prevent the generation of vibration noise and simplify the circuit configuration. According to the inventions of claims 9 and 10,
The configuration of the drive control circuit can be further simplified.

[Brief description of drawings]

FIG. 1 is a half-cut longitudinal side view showing the structure of a three-phase axial type brushless DC motor according to an embodiment of the present invention.

FIG. 2 is a partially cutaway plan view of the same DC motor.

FIG. 3 is a plan view showing an example of a magnetization distribution in a rotor magnet of the same DC motor.

FIG. 4 is a vertical cross-sectional view of a main part showing an example of magnetic flux in a rotor magnet of the same DC motor.

FIG. 5 is a block diagram showing a drive control device for a brushless DC motor according to a first embodiment of the present invention.

FIG. 6 is a signal waveform diagram of essential parts for explaining the operation of the drive control apparatus according to the first embodiment of the present invention.

FIG. 7 is a block diagram showing an example of a drive control device for a brushless DC motor according to a second embodiment of the present invention.

FIG. 8 is a signal waveform diagram of essential parts for explaining the operation of the drive control apparatus according to the second embodiment of the present invention.

FIG. 9 is a block diagram showing an example of a drive control device for a brushless DC motor according to a third embodiment of the present invention.

FIG. 10 is a signal waveform diagram of a main part for explaining the operation of the drive control device according to the third embodiment of the present invention.

FIG. 11 is a block diagram showing an example of a drive control device for a brushless DC motor according to Embodiment 4 of the present invention.

FIG. 12 is a block diagram showing a main part of a drive control device for a brushless DC motor according to a fourth embodiment.

FIG. 13 is a signal waveform diagram for explaining the operation of the main part.

FIG. 14 is another signal waveform diagram for explaining the operation of the main part.

FIG. 15 is a block diagram showing an example of a drive control device for a brushless DC motor according to a fifth embodiment of the present invention.

FIG. 16 is a block diagram showing a main part of a drive control device for a brushless DC motor according to a fifth embodiment.

FIG. 17 is a block diagram showing an example of a drive control device for a brushless DC motor according to Embodiment 6 of the present invention.

FIG. 18 is a plan view showing another example of the magnetization distribution of the rotor magnet applied to the drive control device for the brushless DC motor according to the seventh embodiment of the present invention.

FIG. 19 is a longitudinal cross-sectional view of a main part showing an example of magnetic flux in a rotor magnet of the same DC motor.

FIG. 20 is a block diagram showing an example of a drive control device for a brushless DC motor according to a seventh embodiment of the present invention.

FIG. 21 is a vertical cross-sectional view of a main portion showing another example in which the magnetization distribution of the rotor magnet is applied to the drive control device for the brushless DC motor according to the seventh embodiment of the present invention.

FIG. 22 is a longitudinal cross-sectional view of a main part showing another example in which the magnetization distribution of the rotor magnet is applied to the drive control device for the brushless DC motor according to the seventh embodiment of the present invention.

FIG. 23 is a block diagram showing a drive control device for a conventional three-phase axial type brushless DC motor.

[Explanation of symbols]

A rotor assembly B Stator assembly 1 rotor yoke 2 rotor magnet 2n N pole part 2s S pole 2n1 N pole part 2s1 S pole 3 rotation axes 4 Stator yoke 7 amateur coils 8 rotor position detector 14 Drive control circuit 17 Phase shift circuit 18 First comparator 19 full-wave rectifier 20 Second comparator 21 Reference signal oscillator 22 OR circuit 23 Energization switching circuit 26 Reference signal variable circuit 27 Auto gain control (AGC) circuit 50 correction circuit H rotor position detection signal H1 transition signal H2 inverted signal H3 full wave rectified signal HHL polarity discrimination signal HPWM pulse width modulation (PWM) signal HU1 Positive OR signal HL1 Negative OR signal a Rotation direction e High frequency reference signal g Command signal h amplitude m Maximum amplitude value 0 center level Δθ predetermined electrical angle

─────────────────────────────────────────────────── --- Continuation of the front page (56) References JP-A-5-137375 (JP, A) JP-A-1-248987 (JP, A) JP-A-6-284778 (JP, A) JP-A-7- 107775 (JP, A) JP 7-194084 (JP, A) JP 60-87692 (JP, A) JP 6-98583 (JP, A) JP 56-162991 (JP, A) JP-A-8-126377 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) H02P 6/14 H02P 6/08

Claims (10)

(57) [Claims] 1. A rotor assembly in which a rotor magnet is mounted on a rotor yoke fixed to a rotating shaft, and a stator assembly in which a plurality of armature coils facing the rotor magnet are mounted in a stator yoke in a rotating direction. A drive control circuit for driving and controlling the rotation of the rotor assembly by sequentially energizing each armature coil, and the drive control circuit detects a magnetic pole distribution of the rotor magnet and outputs a rotor position detection signal. A rotor position detector and an automatic gain control (A) for holding the amplitude of each rotor position detection signal at a constant value.
GC) circuit, a phase shift circuit for outputting a plurality of shift signals having a phase difference of a predetermined electrical angle to the rotor position detection signal, and a first triangular wave or sawtooth wave having an audible frequency band or more. A reference signal oscillator for generating a high frequency reference signal, a reference signal variable circuit for variably controlling at least one of the amplitude and center level of the first high frequency reference signal to generate a second high frequency reference signal, And a first comparator for comparing one of the second high-frequency reference signal and the shift signal and outputting a first pulse width modulation (PWM) signal from the difference between the two signals; and first and second high-frequency The other of the reference signals and the transition signal are compared, and the second PW is calculated from the difference between the two signals.
A second comparator for outputting the M signal and the first and second P
A drive control device for a brushless DC motor, comprising: an energization switching circuit that energizes an amateur coil of each phase upon receiving a WM signal. 2. A rotor assembly in which a rotor magnet is mounted on a rotor yoke fixed to a rotating shaft, and a stator assembly in which a plurality of armature coils facing the rotor magnet are mounted in a stator yoke in a rotating direction. A drive control circuit for driving and controlling the rotation of the rotor assembly by sequentially energizing each armature coil, and the drive control circuit detects a magnetic pole distribution of the rotor magnet and outputs a rotor position detection signal. A rotor position detector and an automatic gain control (AG) for holding the amplitude of the rotor position detection signal at a constant value.
C) circuit, and a phase shift circuit for outputting a plurality of shift signals having a phase difference of a predetermined electrical angle with respect to the rotor position detection signal and an inversion signal having a phase difference of 180 ° with respect to the shift signals. And a first comparator for outputting a polarity discrimination signal for discriminating the magnetic pole of the rotor magnet by comparing the shift signal and the inverted signal, and a high frequency reference composed of a triangular wave or a sawtooth wave having an audible frequency band or more. A second reference signal oscillator that generates a signal, and a pulse width modulation (PWM) signal that compares the transition signal and the high frequency reference signal and outputs the difference between the two signals.
And a logic circuit that logically processes the polarity determination signal and the PWM signal and outputs a logical sum signal of both signals,
A drive control device for a brushless DC motor, comprising: an energization switching circuit that energizes the corresponding amateur coil of each phase upon receiving the logical sum signal. 3. A rotor assembly in which a rotor magnet is mounted on a rotor yoke fixed to a rotary shaft, and a stator assembly in which a plurality of armature coils facing the rotor magnet are mounted in a stator yoke in a rotating direction. A drive control circuit for driving and controlling the rotation of the rotor assembly by sequentially energizing each armature coil, and the drive control circuit detects a magnetic pole distribution of the rotor magnet and outputs a rotor position detection signal. A rotor position detector and an automatic gain control (AG) for holding the amplitude of the rotor position detection signal at a constant value.
C) circuit, and a phase shift circuit for outputting a plurality of shift signals having a phase difference of a predetermined electrical angle with respect to the rotor position detection signal and an inversion signal having a phase difference of 180 ° with respect to the shift signals. And a first comparator for comparing the shift signal with the inverted signal to output a polarity discriminating signal for discriminating the magnetic pole of the rotor magnet, and full-wave rectifying the shift signal to output a full-wave rectified signal. A full-wave rectifier, a reference signal oscillator that generates a high-frequency reference signal composed of a triangular wave or a sawtooth wave in the audible frequency band, a high-frequency reference signal and a full-wave rectified signal are compared, and a pulse is generated from the difference between the two signals. A second comparator that outputs a width modulation (PWM) signal, the polarity determination signal, and the PW
A logic circuit for logically processing the M signal and outputting a logical sum signal of both signals, and an energization switching circuit for receiving the logical sum signal and energizing the corresponding amateur coil of each phase are provided. Brushless DC motor drive controller. 4. A rotor assembly in which a rotor magnet is mounted on a rotor yoke fixed to a rotating shaft, and a stator assembly in which a plurality of armature coils facing the rotor magnet are mounted in a stator yoke in a rotating direction. And a drive control circuit for driving and controlling the rotation of the rotor assembly by sequentially energizing each armature coil. The drive control circuit detects a magnetic pole distribution of the rotor magnet to detect a sinusoidal rotor position detection signal. , A rotor position detector that outputs a signal, an automatic gain control (AGC) circuit that holds the amplitude of the rotor position detection signal at a constant value, and a rotor position detection of another phase advanced from the relevant phase. A waveform correction circuit that cuts out a part of the signal and adds it after multiplying the phase by a constant, and full-wave rectifies the output signal of this waveform correction circuit. A full-wave rectifier that outputs a full-wave rectified signal, a first comparator that outputs the polarity determination signal that determines the magnetic pole of the rotor magnet by comparing the transition signal and the inverted signal, and an audible frequency band or higher. A reference signal oscillator that generates a high-frequency reference signal composed of a triangular wave or a sawtooth wave, and a full-wave rectified signal and a high-frequency reference signal are compared, and a pulse width modulation (PWM) signal is output from the difference between the two signals. No. 2 comparator, a logic circuit for logically processing the polarity determination signal and the PWM signal and outputting a logical sum signal of both signals, and energization for receiving the logical sum signal and energizing the corresponding amateur coil of each phase. A drive control device for a brushless DC motor, comprising: a switching circuit. 5. The drive controller for a brushless DC motor according to claim 6, wherein the constant multiplied in the waveform correction circuit is changed in proportion to the motor current. 6. The drive control device for a brushless DC motor according to claim 6, wherein the constant to be multiplied in the waveform correction circuit is changed in proportion to the rotation speed of the motor. 7. A rotor assembly in which a rotor magnet is mounted on a rotor yoke fixed to a rotary shaft, and a stator assembly in which a plurality of armature coils facing the rotor magnet are mounted in a stator yoke in a rotating direction, A drive control circuit for driving and controlling the rotation of the rotor assembly by sequentially energizing each armature coil, and the drive control circuit detects a magnetic pole distribution of the rotor magnet and outputs a rotor position detection signal. A rotor position detector and an automatic gain control (A) for holding the amplitude of each rotor position detection signal at a constant value.
GC) circuit, a full-wave rectifier that full-wave rectifies the rotor position detection signal and outputs a full-wave rectified signal, and compares the rotor position detection signal and the inverted signal with the magnetic pole of the rotor magnet. A first comparator for outputting a polarity discrimination signal for discriminating between, a reference signal oscillator for generating a high frequency reference signal composed of a triangular wave or a sawtooth wave in the audible frequency band, a full wave rectified signal and a high frequency reference signal And a second comparator that outputs a pulse width modulation (PWM) signal based on the difference between the two signals and a logic that logically processes the polarity determination signal and the PWM signal and outputs a logical sum signal of the two signals. A circuit and an energization switching circuit that energizes the corresponding amateur coil of each phase upon receiving the logical sum signal, and the magnetic pole distribution of the rotor magnet facing the amateur coil is uniformly magnetized in the circumferential direction, - a drive control device for a brushless DC motor magnetic pole distribution of the rotor magnet facing the motor position detector, characterized by being heterogeneously magnetized in the circumferential direction. 8. A rotor assembly in which a rotor magnet is mounted on a rotor yoke fixed to a rotating shaft, and a stator assembly in which a plurality of armature coils facing the rotor magnet are mounted on a stator yoke in a rotating direction. A drive control circuit for driving and controlling the rotation of the rotor assembly by sequentially energizing each armature coil, and the drive control circuit detects a magnetic pole distribution of the rotor magnet and outputs a rotor position detection signal. A rotor position detector and an automatic gain control (A) for holding the amplitude of each rotor position detection signal at a constant value.
GC) circuit, a full-wave rectifier that full-wave rectifies the rotor position detection signal and outputs a full-wave rectified signal, and compares the rotor position detection signal and the inverted signal with the magnetic pole of the rotor magnet. A first comparator for outputting a polarity discrimination signal for discriminating between, a reference signal oscillator for generating a high frequency reference signal composed of a triangular wave or a sawtooth wave in the audible frequency band, a full wave rectified signal and a high frequency reference signal And a second comparator that outputs a pulse width modulation (PWM) signal based on the difference between the two signals and a logic that logically processes the polarity determination signal and the PWM signal and outputs a logical sum signal of the two signals. A rotor and a rotor magnet facing the armature coil and the rotor position detector, each of which has a circuit and an energization switching circuit that energizes the corresponding amateur coil of each phase by receiving the logical sum signal.
A drive control device for a brushless DC motor, wherein the drive control device is formed in an uneven shape in the circumferential direction. 9. The set number of rotor position detectors is reduced by one from the number of phases of the amateur coil, and the rotor position detection signal of this missing phase is output from the rotor position detectors of other phases. 9. The drive control device for the brushless DC motor according to claim 1, wherein the rotor position detection signals of No. 1 are differentially amplified and combined. 10. The rotor position detector comprises means for detecting an induced electromotive voltage generated in an armature coil in accordance with the rotation of the rotor assembly. Brushless DC motor drive controller.