JP2017051060A - Motor drive device and motor unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress a deterioration of a motor characteristic while suppressing power for detecting the position of a rotor.SOLUTION: A position detection part 40A outputs a rotational position signal indicating the position of a rotor on the basis of a position detection signal inputted from a position detection element 93A. A drive signal generation part 20A generates a switching signal on the basis of a speed command signal inputted from the outside and the rotational position signal, and outputs the switching signal to an inverter part 30A. An intermittent drive part 13A determines the timing of ON-OFF on the basis of motor drive information inputted from a drive control part 11A, and performs ON-OFF of energization to the position detection element 93A. Thus, the position detection signal can be acquired in accordance with a drive state of a motor 9A.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a motor drive device and a motor unit.

  2. Description of the Related Art Conventionally, there has been known a motor drive device that detects a position of a rotor of a motor using a position detection element and performs drive control of the motor based on the detected position of the rotor. As the position detection element, for example, a Hall element or a Hall IC is used. When detecting the position of the rotor, driving power is supplied to the position detection element.

Japanese Utility Model Laid-Open No. 03-109417 describes a technique for intermittently supplying driving power to a hall element for detecting the open / closed state of a door of an automobile according to an output of a transmitter. Yes. Thus, if the power supply to the Hall element is intermittently performed, the power consumption consumed in the Hall element can be reduced.
Japanese Utility Model Publication No. 03-109417

  However, as in Japanese Utility Model Laid-Open No. 03-109417, if the drive power is simply intermittently supplied to the Hall elements at a constant period, there is a possibility that a delay in detecting the rotor position occurs. For example, if the power supply to the Hall element is stopped at the moment when the magnetic pole of the rotor is switched, the timing for detecting the switching of the magnetic pole is delayed. For this reason, there is a possibility that the motor characteristics may deteriorate depending on the driving state of the motor.

  The objective of this invention is providing the technique which can suppress the fall of a motor characteristic, suppressing the electric power for position detection of a rotor.

  An exemplary first invention of the present application is a motor drive device that detects the position of a rotor of a motor using a position detection element and drives the motor, and for position detection that supplies drive power to the position detection element. A power source, an intermittent drive unit that is provided on an energization line from the position detection power source to the position detection element, and that turns on and off the energization of the position detection element; and a drive control unit that performs drive control of the motor; The drive control unit receives a position detection signal from the position detection element, outputs a rotation position signal indicating the position of the rotor based on the position detection signal, and externally A drive signal generator that generates a PWM signal based on the input speed command signal and the rotational position signal, and an input that supplies a motor drive current to each phase of the motor in accordance with the PWM signal. It has a chromatography data unit, wherein the intermittent drive unit, based on the motor drive information input from the drive control section determines the timing of the ON-OFF to the position detection element.

  According to the first exemplary invention of the present application, by determining the ON-OFF timing based on the motor drive information, the position detection signal can be acquired in accordance with the drive status of the motor. Thereby, it is possible to suppress a decrease in motor characteristics while suppressing power for position detection.

FIG. 1 is a block diagram showing the configuration of the motor drive device according to the first embodiment. FIG. 2 is a diagram illustrating an example of a waveform of each signal in the motor drive device according to the first embodiment. FIG. 3 is a block diagram illustrating a configuration of a motor unit according to the second embodiment. FIG. 4 is a diagram illustrating an example of the waveform of each signal in the motor drive device according to the second embodiment. FIG. 5 is a diagram illustrating an example of the waveform of each signal in the motor drive device according to the second embodiment. FIG. 6 is a diagram illustrating an example of a waveform of each signal in the motor drive device according to the second embodiment. FIG. 7 is a diagram illustrating an example of a waveform of each signal in the motor drive device according to the second embodiment.

  Hereinafter, exemplary embodiments of the present invention will be described with reference to the drawings.

<1. First Embodiment>
First, the motor drive device 10A according to the first embodiment will be described with reference to FIG. 1 and FIG. FIG. 1 is a block diagram showing the configuration of the motor drive device 10A. FIG. 2 is a diagram illustrating an example of the waveform of each signal in the motor drive device 10A.

  In FIG. 2, (p) is an energization waveform to the position detection element 93A, (q) is an output signal waveform from the position detection element 93A when energization is continuously performed, and (r) is a position detection. The waveform of the position detection signal S93A from the element 93A is shown.

  This motor drive device 10A detects the position of the rotor of the motor 9A using the position detection element 93A, and drives the motor 9A. As shown in FIG. 1, the motor drive device 10A includes a drive control unit 11A, a position detection power source 12A, and an intermittent drive unit 13A.

  The drive control unit 11A performs drive control of the motor 9A. The drive control unit 11A includes a drive signal generation unit 20A, an inverter unit 30A, and a position detection unit 40A.

  The drive signal generator 20A generates a switching signal S20A based on a speed command signal input from the outside and a rotational position signal S42A described later. Inverter unit 30A supplies motor drive current S10A to each phase of motor 9A in response to switching signal S20A. The position detection signal S93A is input from the position detection element 93A to the position detection unit 40A. The position detector 40A outputs a rotational position signal S42A indicating the position of the rotor based on the position detection signal S93A.

  The position detection power supply 12A supplies drive power S12A to the position detection element 93A.

  The intermittent drive unit 13A is provided on an energization line from the position detection power source 12A to the position detection element 93A. The intermittent drive unit 13A turns on and off the energization to the position detection element 93A. The intermittent drive unit 13A determines the ON / OFF timing of energization to the position detection element 93A based on the motor drive information S11A input from the drive control unit 11A.

  If drive power is simply supplied intermittently to the position detection element without considering the motor drive status, the motor characteristics may deteriorate depending on the motor drive status. However, as in the motor drive device 10A, by determining the ON / OFF timing of energization to the position detection element 93A based on the motor drive information S11A, the position detection signal S93A is matched to the drive status of the motor 9A. You can get it. Thereby, it is possible to suppress a decrease in motor characteristics while suppressing power for position detection.

  In the present embodiment, the intermittent drive unit 13A turns on the energization of the position detection element 93A during a period including the switching time of the magnetic poles of the rotor. Therefore, as shown in FIG. 2, the position detection element 93 </ b> A of the present embodiment outputs a position detection signal S <b> 93 </ b> A that is a voltage signal that switches between positive and negative according to switching of the magnetic poles of the rotor. The energization ON period in which energization to the position detection element 93A shown in FIG. 2 (p) is ON is set to overlap with the positive / negative switching time of the waveform shown in FIG. 2 (q). As a result, as shown in FIG. 2 (r), the position detection signal S93A output from the position detection element 93A includes the positive and negative switching points of the waveform.

  In this way, by turning on the power to the position detection element 93A in the vicinity of the switching time of the magnetic poles of the rotor, the rotation state of the motor 9A can be detected without delay. Therefore, it is possible to further suppress the deterioration of the motor characteristics.

<2. Second Embodiment>
<2-1. Motor unit configuration>
Next, the configuration of the motor unit 1 according to the second embodiment will be described with reference to FIG. FIG. 3 is a block diagram showing the configuration of the motor unit 1. FIG. 4 is a diagram illustrating an example of a waveform of each signal in the motor driving device 10. In FIG. 4, (a) shows the triangular wave S21, (b) shows the speed command voltage Vsp, and (c) shows the PWM signal S23.

  As shown in FIG. 3, the motor unit 1 of the present embodiment includes a motor 9 and a motor driving device 10. The motor 9 is driven in accordance with supply of a motor driving current S10 described later. The motor 9 of this embodiment is a three-phase brushless DC motor.

  The motor 9 includes an armature 91, a rotor 92, and a position detection element 93. The armature 91 generates a magnetic field in accordance with the supply of driving power. The rotor 92 is rotated by a magnetic field generated from the armature 91. The position detection element 93 detects the position of the rotor 92 and outputs a position detection signal S93. The position detection element 93 of the present embodiment is a Hall element, but other elements such as a Hall IC may be used. In the present embodiment, the motor 9 includes the position detection element 93, but the motor drive device 10 may include the position detection element 93, and the position detection element 93 may be either the motor 9 or the motor drive device 10. Does not have to belong to.

  The motor drive device 10 is a device that controls the drive of the motor 9 by supplying the motor 9 with a motor drive current S10. As shown in FIG. 1, the motor drive device 10 includes a drive control unit 11, a position detection power supply 12, and an intermittent drive unit 13.

  The motor driving device 10 is configured by a package IC. That is, the drive control unit 11, the position detection power source 12, and the intermittent drive unit 13 are provided in one package IC. A control voltage Vcc for driving each part in the package IC is input to the package IC.

  The drive control unit 11 includes a drive signal generation unit 20, an inverter unit 30, a position detection unit 40, and a drive adjustment unit 50. The drive signal generator 20 generates a switching signal S20 based on a speed command voltage Vsp based on a speed command signal input from the outside. The inverter unit 30 supplies the motor drive current S10 to each phase of the armature 91 of the motor 9 according to the switching signal S20. A position detection signal S93 is input from the position detection element 93 to the position detection unit 40. The position detection unit 40 outputs a rotation position signal S42 indicating the position of the rotor 92 based on the position detection signal S93.

  The drive signal generation unit 20 includes a carrier wave oscillation circuit 21, a comparator 22, a PWM signal generation unit 23, a timing control unit 24, and a switching signal generation unit 25. The drive signal generation unit 20 of the present embodiment generates the switching signal S20 in consideration of the switching time of the magnetic poles of the rotor 92 based on the speed command voltage Vsp and the rotation position signal S42 input from the position detection unit 40. To do.

  The carrier wave oscillation circuit 21 is an oscillation circuit that outputs a triangular wave S21 that is a carrier wave at a constant frequency as shown in FIG. That is, the carrier wave oscillation circuit 21 is a carrier wave oscillation circuit that outputs a carrier wave at a constant frequency. Instead of the carrier wave oscillation circuit 21, a carrier wave oscillation circuit that outputs other carrier waves such as a sawtooth wave may be used.

  The comparator 22 is a comparator that compares the speed command voltage Vsp of each phase with the triangular wave S21 and outputs a comparison signal S22. In FIG. 4B, the speed command voltage Vsp is indicated by a solid line, and the triangular wave S21 is indicated by a broken line. The comparison signal S22 output from the comparator 22 of the present embodiment becomes an ON signal when the speed command voltage Vsp exceeds the voltage value of the triangular wave S21, and becomes an OFF signal in other cases.

  The PWM signal generator 23 generates a PWM signal S23 based on the comparison signal S22. As shown in FIG. 4C, the PWM signal S23 corresponding to each phase is turned on during a period when the comparison signal S22 is an ON signal, that is, a period when the speed command voltage Vsp exceeds the voltage value of the triangular wave S21. This is a binary signal that is OFF during a period when the command voltage Vsp is equal to or lower than the voltage value of the triangular wave S21. The duty of the PWM signal S23 increases as the speed command voltage Vsp increases, and the duty decreases as the speed command signal Vsp decreases.

  The timing control unit 24 calculates a phase command voltage S24 for each phase of the motor based on the PWM signal S23. The phase command voltage S24 is a voltage signal indicating the amplitude and cycle of the drive current S10 supplied to the motor 9. In the present embodiment, the timing control unit 24 calculates the phase command voltage S24 based on the rotational position signal S42 input from the A / D conversion unit 42 and the PWM signal S23.

  The switching signal generator 25 generates a switching signal S20 based on the phase command voltage S24. The switching signal S20 is a binary signal composed of an ON signal and an OFF signal.

  As illustrated in FIG. 3, the inverter unit 30 includes six switching elements 31. The inverter unit 30 is a so-called three-phase voltage type inverter. The six switching elements 31 include three pairs of switching elements 31 corresponding to the three phases. Each of the switching elements 31 includes a transistor and a diode. As the switching element 31, for example, an IGBT (insulated gate bipolar transistor) is used. The switching element 31 may be another type of switching element such as a MOSFET (field effect transistor).

  When the motor 9 is driven, three pairs of switching signals S20 each corresponding to three phases are input to the three pairs of switching elements 31. Thereby, the drive timing of each switching element 31 is switched, and the motor drive current S10 corresponding to the three phases is output to each phase of the motor 9.

  The position detection unit 40 includes a signal holding unit 41 and an A / D conversion unit 42. A position detection signal S93 is input from the position detection element 93 to the signal holding unit 41. The position detection element 93 of the present embodiment is an analog Hall element. Therefore, when the rotor 92 rotates at a constant speed, the position detection signal S93 is a sinusoidal voltage signal.

  Further, the position detection unit 40 outputs a rotational position signal S42 based on the position detection signal S93 to the drive adjustment unit 50. In the present embodiment, the position detection signal S93 output from the position detection unit 40 is a voltage signal that switches between positive and negative according to switching of the magnetic poles of the rotor 92. In the present embodiment, the rotation position signal S42 becomes the rotation information S40 output from the position detection unit 40 to the drive adjustment unit 50.

  Note that the position detection unit 40 may further include a rotation number calculation unit that calculates the rotation number of the rotor 92 based on the rotation position signal S42. In that case, the position detection unit 40 may output the rotation number to the drive adjustment unit 50 as the rotation information S40. In other words, the rotation information S40 only needs to include at least one of the rotation position signal S42 and the rotation number of the rotor 92. The operation of each part of the position detection unit 40 will be described later.

  The drive adjustment unit 50 outputs a switching command signal S50 to the intermittent drive unit 13 based on the rotation information S40 input from the position detection unit 40. In the present embodiment, the motor drive information S11 includes this switching command signal S50.

  The position detection power supply 12 is a power supply for supplying drive power S12 to the position detection element 93. The position detection power source 12 of the present embodiment is a DC / DC converter that steps down the control voltage Vcc input to the package IC.

  The intermittent drive unit 13 is provided on the energization line from the position detection power supply 12 to the position detection element 93 and turns on / off the energization to the position detection element 93. The intermittent drive unit 13 determines the ON / OFF timing of energization to the position detection element 93 based on the motor drive information S11 input from the drive control unit 11. A method for determining the timing in the intermittent drive unit 13 will be described later.

  If the current to the position detection element 93 is simply turned on and off without considering the state on the motor 9 side, the detection of the switching of the magnetic pole of the rotor 92 by the position detection element 93 is delayed, and the motor characteristics may be deteriorated. is there. In this embodiment, the position detection signal S93 can be acquired in accordance with the driving status of the motor 9 by determining the ON-OFF timing based on the motor driving information S11. Therefore, it is possible to suppress a decrease in motor characteristics while suppressing power for position detection.

  A triangular wave S 21 is input to the intermittent drive unit 13 from the carrier wave oscillation circuit 21. FIG. 4 (e) shows an example of a basic intermittent energization waveform that serves as a reference in an intermittent ON-OFF period to be described later. As shown in FIG. 4E, the intermittent drive unit 13 turns on and off the energization to the position detection element 93 using the frequency of the triangular wave S21 as a fundamental frequency in the intermittent ON-OFF period. As described above, by using the carrier wave oscillation circuit 21 included in the drive control unit 11 in order to take the timing at which the intermittent drive unit 13 performs intermittent drive, a separate clock circuit may not be provided.

<2-2. About energizing the position detection element>
Next, an energization operation to the position detection element 93 of the motor drive device 10 will be described with reference to FIGS. 5 and 6. 5 and 6 are diagrams illustrating examples of waveforms of signals in the motor drive device 10. FIG.

  5 and 6, (f) is a basic intermittent energization waveform in the intermittent ON-OFF period, (g) is an energization waveform to the position detection element 93, and (h) is assumed to be energized continuously. In this case, the output signal waveform from the position detection element 93, (i) shows the waveform of the position detection signal S93 from the position detection element 93, and (j) shows the waveform of a corrected position detection signal S41 described later.

  In FIG. 5 and FIG. 6, the rotational speed and the rotational speed of the rotor 92 of the motor 9 are different. Therefore, the period of the waveform of the signal indicating the operation of the rotor 92 shown in (h) to (j) is different. Hereinafter, an operation related to energization of the position detection element 93 will be described with reference to FIG.

  The intermittent drive unit 13 of the present embodiment performs switching between the continuous ON period P1 and the intermittent ON-OFF period P2 based on the motor drive information S11. In the present embodiment, the motor drive information S11 includes a triangular wave S21 output from the carrier wave oscillation circuit 21 and a switching command signal S50 output from the drive adjustment unit 50. As shown in FIG. 5G, in the continuous ON period P1, the intermittent drive unit 13 continuously turns on the energization to the position detection element 93. On the other hand, in the intermittent ON-OFF period P2, the energization to the position detection element 93 is turned on and off at a predetermined frequency.

  As described above, the intermittent drive unit 13 receives the triangular wave S <b> 21 from the carrier wave oscillation circuit 21. Here, the intermittent drive unit 13 turns on and off the energization from the position detection power source 12 to the position detection element 93 at the timing shown in FIG. 5F in the intermittent ON-OFF period P2 based on the triangular wave S21. It will be explained as a thing.

  As shown in FIGS. 5F and 5G, the continuous ON period P1 includes only the energization ON period Pon. On the other hand, in the intermittent ON-OFF period P2, the energization ON period Pon and the energization OFF period Poff appear alternately at a predetermined cycle.

  As shown in FIG. 5 (i), the position detection signal S 93 output from the position detection element 93 is a voltage signal that switches between positive and negative according to switching of the magnetic poles of the rotor 92. When the position detection element 93 is energized as shown in FIG. 5G, the position detection signal S93 output from the position detection element 93 has a waveform as shown in FIG. That is, the position detection signal S93 has a waveform indicating the polarity of the rotor 92 during the energization ON period Pon, and is not detected during the energization OFF period Poff.

  The signal holding unit 41 of the position detection unit 40 performs a signal value holding process on the position detection signal S93 and outputs it as a corrected position detection signal S41. In the signal value holding process, the signal holding unit 41 outputs the value of the position detection signal S93 as it is during the energization ON period Pon. On the other hand, in the signal value holding process, the signal holding unit 41 holds and outputs the latest value of the position detection signal S93 in the immediately preceding energization ON period Pon in the energization OFF period Poff.

  Thereby, the correction position detection signal S41 has a waveform as shown in FIG. As shown in FIG. 5 (j), the corrected position detection signal S41 becomes a waveform approximate to the position detection signal S93 during continuous energization shown in FIG. 5 (h) in the energization OFF period Poff by the signal value holding process. .

  Then, the A / D conversion unit 42 outputs the corrected position detection signal S41 obtained by analog / digital conversion to the drive signal generation unit 20 and the drive adjustment unit 50 as the rotation position signal S42. The A / D converter 42 is a binary signal that becomes a High signal when the correction position detection signal S41 has a positive voltage value and becomes a Low signal when the correction position detection signal S41 has a negative voltage value.

  The drive signal generator 20 detects the positive / negative switching time of the rotational position signal S42 as the magnetic pole switching time of the rotor 92. For this reason, the position of the rotor 92 cannot be continuously grasped by a signal obtained by simply analog / digital conversion of the position detection signal S93. Therefore, in the present embodiment, since the position detection unit 40 includes the signal holding unit 41, the rotation position signal S42 is not a broken signal that cannot be detected in the energization OFF period Poff, but a signal that can be recognized continuously. Become.

  The drive adjusting unit 50 determines the switching timing between the continuous ON period P1 and the intermittent ON-OFF period P2 based on the rotational position signal S42 that is the rotation information S40, and outputs the switching command signal S50 to the intermittent driving unit 13. . Specifically, the drive adjustment unit 50 calculates the rotation speed of the rotor 92 based on the rotation position signal S42. Then, the drive adjusting unit 50 refers to a data table (not shown) in which the length of the intermittent ON-OFF period P2 corresponding to the number of rotations of the rotor 92 is described, and the length of the intermittent ON-OFF period P2. To decide.

  FIG. 6 shows each signal when the rotation number of the rotor 92 is smaller than that in FIG. 5, that is, when the rotation period is long. As shown in FIGS. 5 and 6, the intermittent ON-OFF period P <b> 2 is shorter as the rotational speed of the rotor 92 is larger, that is, as the rotational period is shorter. Further, the smaller the rotation speed of the rotor 92, that is, the longer the rotation cycle, the longer the intermittent ON-OFF period P2.

  When the drive adjustment unit 50 determines that the sign of the rotational position signal S42 has been switched, that is, the magnetic pole of the rotor 92 has been switched, the switching command to switch the intermittent drive unit 13 from the continuous ON period P1 to the intermittent ON-OFF period P2. The signal S50 is output. That is, the end point of the continuous ON period P1 is determined based on the positive / negative switching of the rotational position signal S42. Thereby, shortly after the positive / negative switching of the rotational position signal S42, the period determined based on the data table is the intermittent ON-OFF period P2.

  After the period ends, the drive adjustment unit 50 outputs a switching command signal S50 for switching from the intermittent ON-OFF period P2 to the continuous ON period P1 to the intermittent drive unit 13.

  As described above, the drive adjustment unit 50 sets the length of the intermittent ON-OFF period P2 corresponding to the length of the magnetic pole period of the rotor 92. As a result, the time when the next positive / negative switching of the rotational position signal S42 occurs can be predicted, and the continuous ON period P1 can be started before the time of the next switching. That is, the intermittent drive unit 13 performs switching between the continuous ON period P1 and the intermittent ON-OFF period P2 so that the positive / negative switching time of the position detection signal S92 is included in the continuous ON period P1.

  For this reason, the intermittent drive part 13 can turn ON the energization to the position detection element 93 in the period including the switching time of the magnetic poles of the rotor 92. Therefore, the switching of the magnetic poles of the rotor 92 can be detected without delay. As a result, the rotation state of the motor 9 can be grasped without delay, and a reduction in motor characteristics can be suppressed.

  Next, the relationship between the switching timing of the switching element 31 of the inverter unit 30 and the energization timing to the position detection element 93 will be described. FIG. 7 is a diagram illustrating an example of a signal waveform in the motor driving device 10. In FIG. 7, (i) is a switching signal S20, (j) is an output signal waveform from the position detection element 93 when energization is continuously performed, and (k) is a basic in an intermittent ON-OFF period. Intermittent energization indicates the system.

  As shown in FIG. 4D, when the switching signal S20 is switched ON / OFF, that is, when the switching element 31 is switched, switching noise is generated in the position detection signal S93 output from the position detection element 93. For this reason, it is preferable to provide the energization ON period Pon in a period during which no switching noise is added.

  In the example of FIG. 4, the length of the energization ON period Pon is about one fifth of the ON-OFF cycle. Further, the energization ON period Pon is set so as to overlap the center of the pulse of the switching signal S20. Thereby, when the ON period of the switching signal S20 is longer than the energization ON period Pon, the energization ON period Pon and the timing at which switching noise occurs are unlikely to overlap.

  As described above, in the example of FIG. 7, the intermittent drive unit 13 sets the energization ON period Pon in the intermittent ON-OFF period P <b> 2 so that the energization to the position detection element 93 is turned off when the switching element 31 is switched. doing. Thereby, the acquired rotational position signal S42 is not easily affected by the switching noise. As a result, the position information of the rotor 92 can be grasped more accurately, and the deterioration of the motor characteristics can be further suppressed.

  Even in the example of FIG. 7, when the ON period of the switching signal S20 is substantially the same as the energization ON period Pon or shorter than the energization ON period Pon, the energization ON period Pon and the timing at which switching noise occurs overlap. End up. In order to solve the problem, the switching signal generation unit 25 may shift the ON timing of the switching signal S20, or the intermittent drive unit 13 may shift the timing of the energization ON period Pon. In this way, the rotational position signal S42 is less susceptible to switching noise. Therefore, the position information of the rotor 92 can be grasped more accurately and the deterioration of the motor characteristics can be further suppressed.

<3. Modification>
As mentioned above, although exemplary embodiment of this invention was described, this invention is not limited to said embodiment.

  In the above embodiment, the intermittent drive unit 13 turns the energization to the position detection element 93 on and off using the frequency of the triangular wave S21 that is a carrier wave used for generating the PWM signal as a fundamental frequency. This is not the case. The intermittent drive unit may turn on and off the energization to the position detection element using the frequency of the carrier wave output from the carrier wave oscillation circuit of another application included in the drive signal generation unit as a fundamental frequency.

  For example, the switching signal generation unit compares the carrier wave output from the carrier wave oscillation circuit with a voltage signal such as a phase command voltage generated based on the speed command signal Vsp by using a comparator, so that the switching signal is It may be generated. In this case, energization to the position detection element may be turned ON / OFF using the frequency of the carrier wave used for generating the intermittent drive unit switching signal as a fundamental frequency.

  The specific configuration for realizing each part of the motor drive device may be different from the configuration shown in the above embodiment. Moreover, you may combine suitably each element which appeared in said embodiment and modification in the range which does not produce inconsistency.

  The present invention can be used for a motor drive device and a motor unit.

DESCRIPTION OF SYMBOLS 1 Motor unit 9, 9A Motor 10, 10A Motor drive device 11, 11A Drive control part 12, 12A Position detection power supply 13, 13A Intermittent drive part 20, 20A Drive signal generation part 21 Carrier wave oscillation circuit 25 Switching signal generation part 25
30, 30A Inverter section 31 Switching element 40, 40A Position detection section 41 Signal holding section 50 Drive adjustment section 92 Rotor 93, 93A Position detection element S10 Motor drive current S11, S11A Motor drive information S12, S12A Drive power S21 Triangular wave S40 Rotation Information S42, S42A Rotation position signal S50 Switching command signal S93, S93A Position detection signal

Claims (12)

A motor driving device that detects the position of a rotor of a motor using a position detection element and drives the motor,
A position detection power source for supplying driving power to the position detection element;
An intermittent drive unit that is provided on an energization line from the position detection power source to the position detection element and that turns on and off the energization of the position detection element;
A drive control unit for controlling the drive of the motor;
Have
The drive control unit
A position detection unit that receives a position detection signal from the position detection element and outputs a rotation position signal indicating the position of the rotor based on the position detection signal;
A drive signal generator that generates a switching signal based on a speed command signal input from the outside and the rotational position signal;
An inverter for supplying a motor drive current to each phase of the motor in response to the switching signal;
Have
The said intermittent drive part is a motor drive device which determines the ON-OFF timing to the said position detection element based on the motor drive information input from the said drive control part. The motor driving device according to claim 1,
The intermittent drive unit is a motor drive device that turns on the energization of the position detection element during a period including a switching time of the magnetic poles of the rotor. The motor driving device according to claim 1 or 2,
The drive signal generator is
A carrier wave oscillation circuit that outputs a carrier wave at a constant frequency; and
A comparator that compares the voltage signal based on the speed command signal with the carrier wave and outputs a comparison signal;
Have
The motor drive information includes the carrier wave output from the carrier wave oscillation circuit,
The intermittent drive unit is a motor drive device that turns on and off the energization of the position detection element using the frequency of the carrier wave input from the carrier wave oscillation circuit as a fundamental frequency. The motor drive device according to any one of claims 1 to 3,
The position detector is
A motor driving device having a signal holding unit that outputs the value of the position detection signal in the energization ON period and holds and outputs the latest value of the position detection signal in the energization ON period immediately before in the energization OFF period . The motor drive device according to any one of claims 1 to 4,
The intermittent drive unit is based on the motor drive information.
A continuous ON period in which energization of the position detection element is continuously turned ON;
An intermittent ON-OFF period in which energization to the position detection element is turned on and off at a predetermined frequency;
A motor drive device that performs switching. The motor driving device according to claim 5,
The position detection signal output from the position detection element is a voltage signal that switches between positive and negative according to switching of the magnetic poles of the rotor,
The intermittent drive unit performs switching between the continuous ON period and the intermittent ON-OFF period so that a positive / negative switching time of the position detection signal is included in the continuous ON period. The motor driving device according to claim 5 or 6, wherein
The drive control unit
A drive adjustment unit to which rotation information including at least one of the rotation position signal and the rotation number of the rotor is input from the position detection unit;
The drive adjusting unit determines a switching timing between the continuous ON period and the intermittent ON-OFF period based on the rotation information, and outputs a switching command signal to the intermittent driving unit,
The intermittent drive unit is a motor drive device that performs switching between the continuous ON period and the intermittent ON-OFF period based on the switching command signal. The motor driving device according to claim 7,
The drive adjusting unit refers to the data table in which the length of the intermittent ON-OFF period according to the number of rotations of the rotor is described, and based on the rotation information, A motor drive that determines the length. The motor driving device according to claim 7 or claim 8,
When the drive adjustment unit determines that the magnetic pole of the rotor has been switched, the drive adjustment unit outputs the switching command signal for switching from the continuous ON period to the intermittent ON-OFF period to the intermittent drive unit. The motor drive device according to any one of claims 1 to 9,
The inverter unit has a plurality of switching elements,
The switching element is turned on and off in accordance with the switching of the voltage value of the switching signal between High and Low,
The intermittent drive unit is a motor drive device that turns off the energization of the position detection element when the switching element is switched. The motor drive device according to any one of claims 1 to 10,
The position detection power source, the intermittent drive unit, and the drive control unit are provided in one package IC,
A control voltage for driving each part of the package IC is input to the package IC,
The position detection power supply is a motor drive device that is a DC / DC converter that steps down the control voltage. A motor drive device according to any one of claims 1 to 11,
The motor;
A motor unit having
The motor is
An armature that generates a magnetic field in accordance with the supply of the motor drive current;
The rotor rotating by a magnetic field generated by the armature;
The position detection element for detecting the position of the rotor and outputting the position detection signal;
Having a motor unit.

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