JP2011104070A - Washing machine - Google Patents

Abstract

To provide a washing machine with less noise and vibration during feedback operation.
A sine wave generated when a microcomputer 64 applies a sine wave voltage of a predetermined frequency to a DC brushless motor motor 24 via an inverter circuit 57 to drive a rotary drum 20 to drive it in an open loop. The microcomputer 64 detects the phase shift amount between the phase of the voltage and the phase of the rotor position signal output from the hall sensors 63 a, 63 b, 63 c and stores it in the memory 65, and the microcomputer 64 performs DC brushless via the inverter circuit 57. When the motor 24 is driven by feedback control, the microcomputer 64 corrects the sine wave voltage supplied to the DC brushless motor 24 based on the phase shift amount stored in the memory 65, thereby reducing noise and vibration during feedback operation. A washing machine can be provided.
[Selection] Figure 1

Description

  The present invention relates to a drum-type washing machine for washing clothes in a rotating drum.

  Induction motors used to be the mainstream for driving washing machines in washing machines, but DC brushless motors are now commonly used to reduce motor electromagnetic noise and save energy. (For example, refer to Patent Document 1).

  In a DC brushless motor, it is necessary to supply a sinusoidal voltage to the DC brushless motor in time with the rotor position. For this reason, when the DC brushless motor rotation speed such as washing and stirring is low, feedback control (synchronous operation) is performed to detect the rotor position and control the sinusoidal voltage supplied to the DC brushless motor. On the other hand, when the rotational speed of the DC brushless motor such as dehydration is high, the control timing of the sinusoidal voltage supplied to the DC brushless motor is shifted when the rotor position is detected and feedback control is performed. In general, a sinusoidal voltage having a frequency is supplied to a DC brushless motor to perform open loop driving (asynchronous operation).

Japanese Patent Laid-Open No. 10-15278

  However, in such a conventional system, if the mounting accuracy of the sensor for detecting the rotor position in feedback control is poor or the sensor sensitivity varies, the detection error of the rotor position becomes large. If the detection error of the rotor position becomes large and the timing for switching the energization to the stator windings shifts, the power factor between the current flowing through the stator windings and the induced voltage generated in the stator windings will be low, resulting in an increase in power consumption. As a result, the DC brushless motor torque becomes uneven, causing problems such as increased vibration and noise, and delayed detection when a DC brushless motor abnormality occurs.

  In the feedback control, the phase shift between the rotor and the stator caused by load fluctuations is corrected by initializing the phase of the sinusoidal voltage supplied to the DC brushless motor every time the rotor position is detected. For this reason, when a phase shift occurs between the rotor and the stator due to load fluctuation or the like, the waveform of the sinusoidal voltage supplied to the DC brushless motor every time the rotor position is detected is distorted.

  When distortion occurs in the waveform of the sinusoidal voltage supplied to the DC brushless motor, a DC brushless motor torque fluctuation occurs, which hinders maintaining the set rotation speed and at the same time increases noise and vibration. In addition, noise is generated due to distortion in the waveform of the sinusoidal voltage. In particular, in a drum washing machine, a cleaning power is obtained by an impact generated by lifting and dropping the laundry, so that a load fluctuation during one rotation of the DC brushless motor becomes large, and a distortion of a waveform of a sinusoidal voltage supplied to the DC brushless motor becomes large. It was.

  The present invention solves the above-described conventional problems, and an object thereof is to provide a washing machine with less noise and vibration during feedback operation.

  In order to achieve the above object, a drum type washing machine of the present invention includes a washing drum, a DC brushless motor that drives the washing drum, and a rotor position of the DC brushless motor. And a control means for supplying the DC brushless motor with a waveform-controlled sine wave voltage having an inverter means and a storage means, and the control means is a sine wave voltage having a predetermined set frequency. Is detected and stored in the storage means by detecting the phase shift amount between the phase of the sine wave voltage generated when the DC brushless motor is supplied and driven in an open loop and the phase of the position signal output by the position detection means. In addition, the DC brushless motor is driven by performing feedback control based on the position signal output from the position detecting means. Wherein it is based on the phase shift amount that is to correct the sinusoidal voltage supplied to the DC brushless motor Rutoki.

  As a result, if the accuracy of rotor position detection is poor due to external factors, a stable sine wave could not be supplied to the DC brushless motor, and a large amount of noise and vibration could occur during DC brushless motor control. When a phase shift between the phase of the sine wave voltage and the phase of the position signal is detected during driving and feedback is performed based on the position signal, the phase shift is reduced, and noise and vibration generated during feedback can be reduced.

  The drum-type washing machine of the present invention prevents the detection error of the rotor position from becoming large if there is a variation in the sensor sensitivity due to poor sensor mounting accuracy in detecting the rotor position in feedback control. The amount of deviation between the phase of the sine wave voltage and the phase of the position signal output by the position detection means is detected, feedback is performed based on the position signal output by the rotor position detection means, and DC is determined based on the amount of phase deviation. By correcting the sine wave voltage supplied to the brushless motor, it is possible to provide a washing machine with less noise and vibration during feedback operation.

Side sectional view of the drum-type washing machine according to Embodiment 1 of the present invention. Block diagram of the drum type washing machine Drive circuit diagram for motor of the drum type washing machine Voltage waveform diagram applied to the motor of the drum type washing machine Motor rotation speed and phase relationship diagram during open loop control of the drum type washing machine

  A first invention is a sine having a rotary drum, a DC brushless motor for driving the rotary drum, a position detecting means for detecting a rotor position of the DC brushless motor, an inverter means and a storage means, and performing waveform control. Control means for supplying a sine wave voltage to the DC brushless motor, and the control means supplies a sine wave voltage of a predetermined set frequency to the DC brushless motor to generate an open loop drive. A phase shift amount between the phase and the phase of the position signal output by the position detection means is detected and stored in the storage means, and feedback control based on the position signal output from the position detection means is performed to perform the DC control. When the brushless motor is driven, it is supplied to the DC brushless motor based on the phase shift amount. By making the washing machine characterized by correcting the string voltage, it is impossible to supply a stable sine wave to the DC brushless motor if the accuracy of rotor position detection is poor due to external factors. Large noise and vibration sometimes occurred. However, when detecting the phase shift between the phase of the sine wave voltage and the phase of the position signal during open loop drive and performing feedback based on the position signal, the phase shift is small. Therefore, noise and vibration generated during feedback can be reduced.

  In particular, according to a second aspect, in the first aspect, the control means has a plurality of predetermined set frequencies, detects a phase shift amount with respect to each of the plurality of predetermined set frequencies, and determines the phase shift amount. By using the washing machine characterized by storing in the storage means, the detection error of the position detection means can be corrected more accurately, and the position detection accuracy can be increased.

  In a third aspect of the invention, in particular, in the first aspect of the invention, the control means performs open loop driving for detecting a phase shift amount in the forward rotation direction and the reverse rotation direction of the DC brushless motor, and the phase shift with respect to each rotation direction. By detecting the amount and storing the phase shift amount in the storage means, the phase shift amount can be detected without unevenness regardless of the rotation of the DC brushless motor (rotation of the rotating drum). Therefore, the phase shift amount can be output with higher accuracy and the detection error can be reduced.

  According to a fourth aspect of the present invention, in particular, in any one of the first to third aspects, the control means sets the DC brushless phase of the sine wave voltage supplied to the DC brushless motor by a set value corresponding to the DC brushless motor rotational speed. By making the washing machine characterized by shifting with respect to the rotor position of the motor, not only the efficiency of the DC brushless motor can be increased, but also the detection accuracy of the rotor position can be increased.

  The fifth invention is characterized in that, in any one of the first to fourth inventions, the control means corrects the phase shift of the sine wave voltage with respect to the position signal generated by the load fluctuation of the DC brushless motor. By using the washing machine, the phase shift of the sine wave due to load fluctuation is eliminated, and by correcting it, noise and vibration generated during feedback can be suppressed.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the present invention is not limited to the present embodiment.

(Embodiment 1)
1 is a side sectional view of a drum type washing machine according to Embodiment 1 of the present invention, FIG. 2 is a block circuit diagram of the drum type washing machine, and FIG. 3 is a motor drive circuit of the drum type washing machine. FIGS. 4 and 4 are voltage waveforms applied to the motor of the drum type washing machine, and FIG. 5 is a phase relationship diagram of the motor speed and the open loop control of the drum type washing machine.

  As shown in FIG. 1, the rotary drum 20 is formed in a bottomed cylindrical shape, and a large number of water passage holes 21 are provided on the entire surface of the outer periphery, and the rotary drum 20 is rotatably disposed in the water tank 22. A rotation axis (rotation center axis) 23 is provided at the rotation center of the rotary drum 20 in a substantially inclined direction, and the axial center direction of the rotation drum 20 is inclined downward from the front side toward the back side. The rotation of the DC brushless motor 24 attached to the outer bottom surface of the water tank 22 is stretched between a driving pulley 25 fixed to the rotating shaft of the DC brushless motor 24 and a driven pulley 26 fixed to the end of the rotating shaft 23. The V-belt 27 is transmitted to the rotary shaft 23 to drive the rotary drum 20 to rotate in the forward and reverse directions. Several protruding plates 28 are provided on the inner wall surface of the rotating drum 20 to perform a stirring operation of lifting and dropping the clothes in the rotating direction, so-called tapping.

  An opening 29b provided in the upward inclined surface 29a on the front side of the washing machine body 29 is covered with a lid 30 so that it can be opened and closed. The laundry can be taken in and out of the rotary drum 20 through the drum clothing entrance 20a. Note that the lid 30 has a configuration capable of operating the lid lock 31 so as not to open in order to maintain the safety of the user during the driving operation.

The aquarium 22 is swingably supported by a washing machine main body 29 by a spring 31 and a damper 32, and is supported in an anti-vibration manner. One end of a drainage path 33 is connected to the lower part of the aquarium 22, and the other end of the drainage path 33 is connected to the lower end of the drainage path 33. The washing water in the water receiving tub 22 is drained by connecting to the drain valve 34.

  A detergent case 35 is provided at the front upper part of the washing machine main body 29. The detergent case 35 is connected to a first water supply hose (first water supply path) 37a that communicates with a water supply valve (water supply means) 36 provided at the upper rear portion of the washing machine main body 29. 2nd water supply hose (1st water supply path) 37b connected to 22 is connected. When the water supply valve 36 is opened, tap water is supplied to the detergent case 35 via the first water supply hose 37a. After the tap water is sprinkled on the detergent charging box 34, the tap water and the detergent are combined. The water tank 22 is configured to be charged into the water tank 22 through the second water supply hose 37b.

  One end of a third water supply hose 37c (second water supply path) is connected to the detergent case 35 in the vicinity of the connection portion of the first water supply hose 37a, and the other end of the third connection hose 37c is a rotating drum. 20 is connected to a water supply base 38 that opens to a position where water is supplied from the front opening 20 a toward the inside of the rotary drum 20. The water level detection means 39 detects the water level in the water tank 22. The inner bottom of the water tub 22 is provided with a heater 40 for heating the washing water and a temperature detection means 41 for detecting the temperature of the washing water, and has a function of washing the laundry in the rotary drum 20 with warm water.

  The control device 42 is configured as shown in the control circuit diagram of FIG. 2, and controls the operation of the DC brushless motor 24, the water supply valve 36, the heater 40, etc., and sequentially controls a series of steps of washing, rinsing and dehydration. And a control means 43 comprising a microcomputer.

  The control means 43 inputs information from the input setting means 44 for setting the driving course and the like, displays the information on the display means 45 based on the information and informs the user, and starts the operation by the input setting means 44. Is set, the data from the water level detecting means 39 for detecting the water level in the water tank 22 is input and the operation of the DC brushless motor 24, the water supply valve 36, the heater 40, etc. is controlled via the power switching means 46. And do laundry.

  The rotational speed detection means 47 detects the rotational speed of the rotary drum 20 by detecting the rotational speed of the DC brushless motor 24, and outputs the detection result to the control means 43. The storage means 48 stores data necessary for a series of controls. The storage means 48 may be a non-volatile memory so that the stored contents are not lost even when the power is turned off. 49 is a commercial power source, and 50 is a power switch. In the present embodiment, the rotation shaft 23 is provided in a substantially inclined direction at the rotation center of the rotary drum 20, and the axial center direction of the rotary drum 20 is inclined downward from the front side to the back side. However, the rotary shaft 23 may be provided in the substantially horizontal direction at the rotation center of the rotary drum 20 and the axial center direction of the rotary drum 20 may be provided in the substantially horizontal direction.

  Hereinafter, a method for driving a DC brushless motor will be described with reference to FIGS. 3, 4, and 5.

  The memory 65 stores programs such as the operation contents of each process such as washing, rinsing, and dehydration, and the execution order of the processes. The microcomputer 64 controls the opening and closing of the water supply valve 36 and the ON / OFF switching of the drain valve 34 and the DC brushless motor 24. It should be noted that the contents of the operations of each process such as washing, rinsing, dehydration, etc., and the execution order of the processes (that is, the processing course) may be stored in the memory inside the microcomputer 64 instead of the memory 65.

The microcomputer 64 inputs a signal such as a laundry reservation from the display unit 45 and outputs a signal for displaying the progress of the operation or the like to the display unit 45. The AC voltage output from the commercial power supply 49 is supplied to the rectifier circuit 55 via the reactor 54, and is converted into a pulsating DC voltage by the rectifier circuit 55. The rectifier circuit 55 uses a diode bridge. The DC voltage rectified by the rectifier circuit 55 is smoothed by the smoothing capacitors 56a and 56b.

  The positive polarity side of the capacitor 56 a is connected to the positive output terminal of the rectifier circuit 55. The negative polarity side of the capacitor 56 a and the positive polarity side of the capacitor 56 b are connected to the side of the commercial power supply 53 that is not connected to the reactor 54. The negative polarity side of the capacitor 56 b is connected to the negative output terminal of the rectifier circuit 55. Then, the DC voltage smoothed by the capacitors 56 a and 56 b is supplied to the inverter circuit 57.

  The inverter circuit 57 converts the DC voltage into a three-phase AC voltage. The inverter circuit 57 has six NPN transistors 58a to 58c and 59a to 59c as a switching means in a three-phase full-wave bridge configuration. The six transistors 58a to 58c and 59a to 59c are connected in parallel with diodes 60a to 60c and 61a to 61c, respectively. The connection points a, b, and c of the transistors 58a to 58c and the transistors 59a to 59c are connected to the stator coils Lu, Lv, and Lw of the respective phases (U phase, V phase, and W phase) of the DC brushless motor 24. The bases of the transistors 58 a to 58 c and 59 a to 59 c are connected to the drive circuit 62.

  The DC brushless motor 24 has hall sensors 63a, 63b, and 63c that detect the rotational position of the rotor. Rotor position signals Hu, Hv, and Hw output from the hall sensors 63a, 63b, and 63c are input to the microcomputer 64. The microcomputer 64 outputs drive signals P1 to P6 to the drive circuit 62.

  The drive circuit 62 PWM-chops and amplifies the drive signals P1 and P2 at several to several tens of kHz and supplies them to the bases of the transistors 58a and 59a, respectively, and PWM chops the drive signals P3 and P4 at several to several tens of kHz. Then, the signals are amplified and supplied to the bases of the transistors 58b and 59b, respectively, and the drive signals P5 and P6 are PWM chopped at several to several tens of kHz and amplified and supplied to the bases of the transistors 58c and 59c, respectively.

  During the low-speed rotation operation, the microcomputer 64 drives the drive signal P1 so that the rotor position signals Hu, Hv, Hw and the sinusoidal voltages Eu, Ev, Ew supplied to the stator windings Lu, Lv, Lw are synchronized. ˜P6 is output to the drive circuit 62 to control the rotation of the DC brushless motor 24. On the other hand, during high-speed rotation operation, the microcomputer 64 outputs drive signals P1 to P6 to the drive circuit 62 so that the sinusoidal voltages Eu, Ev, and Ew become the set frequencies, and the DC brushless motor 24 is open-loop driven. Rotation control.

  Here, feedback control performed during low-speed rotation operation will be described. First, voltage waveforms applied to the motor 24 by the inverter circuit 57 will be described with reference to FIG.

  FIG. 4B shows a U-phase stator winding of the motor 24 when the motor 24 is constantly driven at a constant rotational speed based on the rotor position signals Hu, Hv, and Hw shown in FIG. Voltage Eu applied to Lu (hereinafter referred to as applied voltage Eu), voltage Ev applied to V-phase stator winding Lv (hereinafter referred to as applied voltage Ev), voltage Ew applied to W-phase stator winding Lw (hereinafter applied) Voltage Ew). In order to obtain the applied voltages Eu, Ev, Ew, the microcomputer 64 operates as follows. The microcomputer 64 generates drive signals P1 and P2 as shown in (d1) and (d2) of FIG.

The drive signal P1 is amplified by the drive circuit 62 and then supplied to the base of the transistor 58a. The drive signal P2 is amplified by the drive circuit 62 and then supplied to the base of the transistor 59a. As a result, the voltage E0u applied to the U-phase stator winding Lu becomes PWM (Pulse Width Modulation) as shown in FIG.
). This waveform is substantially equivalent to the applied voltage Eu shown in FIG. Further, as shown in FIG. 4B, the inverter circuit 57 uses the V-phase stator winding to apply the applied voltage Ev that is delayed in phase by 240 ° in electrical angle with respect to the applied voltage Eu when the U phase is used as a reference. An applied voltage Ew having a phase delay of 120 ° is applied to Lv, respectively, to the W-phase stator winding Lw. In this way, the rotor of the motor 24 rotates in the forward rotation direction by applying a sinusoidal voltage having a phase shift to each phase of the motor 24.

  When the V phase is used as a reference, the applied voltage Eu delayed in phase by 120 ° with respect to the applied voltage Ev is applied to the U-phase stator winding Lu, and the applied voltage Ew delayed by 240 ° is applied to the W-phase stator. When applied to each of the windings Lw and the W phase is used as a reference, an applied voltage Eu delayed in phase by 240 ° with respect to the applied voltage Ew is applied to the U-phase stator winding Lu by 120 ° in phase. A voltage Ev is applied to each V-phase stator winding Lv.

  Here, when an appropriate electric power is supplied and the open loop control drive is performed, the motor efficiency always rotates at a phase (maximum phase of the rotor stator) shown in FIG. 5, but the Hall sensors 63a, 63b, 63c When there is an error in the attachment position or sensitivity, the rotor position signal does not accurately indicate the rotor position. Therefore, the phase shift amount between the inversion timing of the rotor position signal and the zero cross point of the drive voltage waveform data described above is shown in FIG. Does not match the optimum phase of the rotor stator shown in FIG.

  The optimum phase of the rotor stator is stored in the memory 65, and the microcomputer 64 calculates the rotor position detection error by comparing the phase shift amount between the inversion timing of the rotor position signal and the zero cross point of the drive voltage waveform data. The calculation result is stored in the memory 65. For example, since the optimal phase of the motor is 0 ° at 300 r / min, the rotor position at the Hall sensor 63a is when the phase shift amount between the inversion timing of the rotor position signal Hu and the zero cross point of the drive voltage waveform is + 30 °. When the phase shift amount between the inversion timing of the rotor position signal Hu and the zero cross point of the drive voltage waveform is −30 °, the detection error of the rotor position at the Hall sensor 63a is also −30 °. Become.

  Since the sensitivity of the Hall sensor varies depending on the motor rotation speed, a plurality of rotation speeds to be detected may be set. For example, if detection is performed at 200 r / min in addition to 300 r / min, the optimum phase of the rotor stator is −10 ° at 200 r / min. Therefore, the phase between the inversion timing of the rotor position signal Hu and the zero cross point of the drive voltage waveform data Hu. When the deviation amount is + 30 °, the detection error of the rotor position in the hall sensor 63a is + 40 °, and the phase deviation amount between the inversion timing of the rotor position signal Hu and the zero cross point of the drive voltage waveform data 41u is −30 °. In some cases, the Hall sensor error is -20 °.

  Next, a case will be described in which there is an error in rotor position detection, phase correction is performed, and the phase of the applied voltage is shifted with respect to the inversion timing of the rotor position signal in accordance with the motor rotation speed.

  If the phase correction amount when correcting the error in rotor position detection and the phase shift amount when shifting the phase of the applied voltage with respect to the inversion timing of the rotor position signal according to the motor speed, the inversion timing of the rotor position signal It is assumed that the phase of the drive waveform data is advanced by θ1. When the rotor speed increases instantaneously due to the load fluctuation and the drive waveform data is delayed by θ2 with respect to the rotor position signal, the frequency of the drive waveform data is multiplied by (2 × θ2 + θ1) / θ2. When the delay phase (θ2) is updated, the frequency of the drive waveform data is made to correspond to the rotor rotational speed detected by the rotor position signal.

Further, when the rotor rotational speed decreases instantaneously due to load fluctuation and the drive waveform data is advanced by θ3 with respect to the rotor position signal, the frequency of the drive waveform data is set to θ3 without being reset at the inversion timing of the rotor position signal. / (2 × θ3−θ1) times. When updated to twice the advance phase (θ3), the frequency of the drive waveform data is made to correspond to the rotor rotational speed detected by the rotor position signal.

  By performing such control, even when the motor load fluctuates even when the rotor position detection error is corrected and the phase of the applied voltage is shifted with respect to the inversion timing of the rotor position signal according to the motor rotation speed However, a sinusoidal voltage can be made into a smooth waveform, a stable rotation speed can be obtained without abrupt fluctuations in motor rotation, and a change in motor torque can be minimized, so noise and vibration can be reduced. . In addition, since the distortion of the sinusoidal voltage is small, the generation of noise is reduced, and the noise countermeasure components can be reduced.

  As described above, the drum type washing machine according to the present invention can reduce noise and vibration generated at the time of feedback, can reduce costs, and can suppress variation due to performance of each motor. Therefore, it is useful as a drum type washing machine for washing clothes in a rotating drum.

24 DC brushless motor 34 Drain valve 36 Water supply valve 57 Inverter circuit 62 Drive circuit 64 Microcomputer

Claims (5)

A DC brushless motor having a rotary drum, a DC brushless motor for driving the rotary drum, a position detecting means for detecting a rotor position of the DC brushless motor, an inverter means and a storage means, and performing waveform control. Control means for supplying to the motor, wherein the control means supplies a sine wave voltage of a predetermined set frequency to the DC brushless motor to cause open-loop driving and the phase of the sine wave voltage and the position detection means. When the DC brushless motor is driven by performing feedback control based on the position signal output from the position detection means and detecting the phase shift amount with respect to the phase of the position signal output by the storage means and storing it in the storage means The sine wave voltage supplied to the DC brushless motor is compensated based on the phase shift amount. A washing machine which is characterized in that. The control means has a plurality of predetermined set frequencies, detects a phase shift amount for each of the plurality of predetermined set frequencies, and stores the phase shift amount in the storage means. Washing machine. The control means performs open loop drive for detecting the phase shift amount in the forward rotation direction and the reverse rotation direction of the DC brushless motor, detects the phase shift amount with respect to each rotation direction, and stores the phase shift amount in the storage means. The washing machine according to claim 1, wherein the washing machine is stored. The control means shifts the phase of the sine wave voltage supplied to the DC brushless motor by a set value corresponding to the rotational speed of the DC brushless motor with respect to the rotor position of the DC brushless motor. A washing machine according to claim 1. The washing machine according to any one of claims 1 to 4, wherein the control means corrects a phase shift of the sine wave voltage with respect to a position signal generated by a load fluctuation of the DC brushless motor.