JP4398889B2 - Motor drive device and washing machine - Google Patents

Description

  The present invention relates to a motor driving device for rotationally driving a rotating container that contains a stored item, and more particularly to a motor driving device for a washing machine that uses a rotating container as a drum that rotates about a horizontal axis or an inclined axis.

  For example, Patent Document 1 discloses a horizontal drum type washing machine that rotates about a horizontal axis. Since it is easy to perform dehydration and drying using this drum, it is used in a washing machine that performs dehydration and drying especially after the end of washing. In addition, the horizontal drum type washing machine has the advantages that the laundry to be accommodated is less damaged and the amount of water required for washing is less than that of a washing machine having a vertical washing tub.

  In this drum type washing machine, washing is performed by rotating the drum containing the laundry in the outer tub in which the washing liquid is stored. At this time, the drum is usually rotated at a low speed of about 50 rpm. The laundry in the drum is lifted onto the washing liquid by the rotation of the drum, and falls toward the washing liquid while being raised due to gravity. In this manner, the laundry is repeatedly lifted and dropped from the washing liquid, and washing is performed.

  The drum is rotated by the motor torque generated by the motor, but the magnitude of the load torque applied to the motor by the laundry varies in one rotation depending on the position of the laundry. As shown in FIG. 11, the load torque becomes the largest while the laundry is being lifted up in the washing liquid (first state in FIG. 11). Thereafter, the laundry is lifted onto the washing liquid and lifted while being stuck to the rotating drum by centrifugal force, so that the load torque decreases (second state in FIG. 11). When the laundry falls due to gravity, the load torque is minimized (third state in FIG. 11).

A torque difference between the load torque and the motor torque causes a fluctuation in the rotation speed of the drum, which causes the washing machine to vibrate. Patent Documents 2 and 3 describe methods for controlling the motor torque with high accuracy in order to reduce fluctuations in the rotational speed of the drum. In Patent Document 2, the generated torque of the motor is controlled with high accuracy in each operation of washing, rinsing, dehydration and drying by vector control of the motor based on the current flowing through the motor. Patent Document 3 discloses a method for controlling motor torque so as to cancel load torque fluctuation during one rotation of a washing machine motor.
JP-A-4-336097 JP 2003-169993 A JP 2002-95281 A

  The speed control means of Patent Document 2 is a method of controlling by feedback based on the deviation between the speed command and the rotational speed of the motor. However, the followability to sudden load torque fluctuation when the laundry falls is not good. In Patent Document 3, the load torque fluctuation caused by the laundry being unevenly distributed in a certain place in the washing tub is targeted, but a sudden load in which the laundry falls in the middle of ascent like a drum-type washing machine. Fluctuations are not taken into account.

  In view of the above, the present invention reduces the fluctuation in the rotation speed of the drum by controlling the drive of the motor against the fluctuation in the load torque caused by the change in the state of the laundry accompanying the rotation of the drum, thereby reducing the vibration of the washing machine An object of the present invention is to provide a motor drive device that can suppress the above-described problem.

  The present invention includes a motor that rotationally drives a rotating container that contains an object, an object state detector that detects a state of the object that changes as the rotating container rotates, and a state change of the object. And a control unit that drives and controls the motor in accordance with the load torque applied to the motor.

  As the rotating container rotates, the state of the contents changes. Here, the state of the contained item is the position of the contained item in the rotating container or the distribution of the contained item such as the overlapping or spreading of the contained items. The rotation of the rotating container fluctuates due to the change in the state of the contents, and the load torque applied to the motor also fluctuates. The rotating container is rotated by motor torque generated by the motor. Therefore, by controlling the driving of the motor in accordance with the change in the state of the contents, the motor torque changes, and the motor torque follows the fluctuation of the load torque. That is, a control part controls the electric current or voltage supplied to a motor so that it may become a motor torque according to load torque. As a result, the torque difference between the two becomes small, and the rotation of the rotating container does not fluctuate.

  Specifically, a motor that accommodates an object and rotationally drives a rotating container that rotates around a horizontal axis or an inclined axis, a rotor position detector that detects a rotational position of the rotor of the motor, and the rotor position detection And a control unit that drives and controls the motor based on a position signal from the control unit, and a storage object state detection unit that detects the state of the storage object that is changed by the action of centrifugal force and gravity due to rotation of the rotating container is provided. The control unit controls a current or a voltage supplied to the motor in accordance with a change in the state of the contents. At this time, the rotation of the rotating container is rotationally driven at a predetermined rotational speed such that the centrifugal force acting on the container is smaller than the gravity, and the container falls while rising as the rotating container rotates.

  Here, the storage object state detection unit detects a change in the state of the storage object based on the rotor position detection interval based on the position signal of the rotor position detection unit. The interval between the position signals output when the rotor position is detected from the rotor position detector corresponds to the rotational speed of the rotating container, and the change in the rotational speed corresponds to the variation in the load torque. Since the variation of the load torque is caused by the change in the state of the contained item, the change in the state of the contained item can be detected by detecting the rotor position detection interval. Therefore, it is possible to detect a change in the state of the stored object using the existing rotor position detecting unit without providing the stored object state detecting unit.

  The rotor position detection unit includes a plurality of Hall sensors that respectively output position signals based on the rotational position of the rotor. The motor is a brushless motor including a rotor having a permanent magnet and a stator around which a three-phase winding is wound. The motor rotates the rotary container by a direct drive method. Thus, by using a brushless motor, it is possible to operate more efficiently than the induction motor and to control the motor torque with high accuracy. By adopting the direct drive method, it is possible to accurately detect the change in the state of the contained item from the rotor position detection interval without time delay, and to transmit the motor torque to the rotating container.

  A motor current detection unit that detects a current supplied to the motor is provided, and the control unit limits a maximum value of at least one of the current and voltage supplied to the motor based on the detected motor current value. Alternatively, an inverter unit that applies the drive voltage determined by the control unit to the motor and a DC current detection unit that detects a DC current flowing through the inverter unit are provided, and the control unit sets the detected DC current value to Based on this, the maximum value of at least one of the current and voltage supplied to the motor is limited. As a result, it is possible to prevent the motor from being destroyed or deteriorated due to an excessive current flowing through the motor.

  Here, by applying the motor driving device described above to a washing machine that stores laundry as a container in a drum that is a rotating container, the rotational speed fluctuation of the drum is reduced by performing motor drive control, Vibration of the washing machine is suppressed.

  According to the present invention, by controlling the drive of the motor in accordance with the change in the state of the container, the torque difference between the load torque and the motor torque that fluctuate due to the change in the state of the container can be reduced. Variations in the rotational speed of the rotating container can be reduced. Therefore, vibration can be suppressed and generation of noise can be reduced by applying to drive control of a motor in an electric device such as a washing machine.

  The drum type washing machine of this embodiment is shown in FIGS. As shown in FIG. 1, an opening / closing door 3 is provided on the front surface of the main body exterior portion 1 that forms the outer wall of the washing machine, and can be opened and closed. An operation panel 11 having operation keys and a display unit is provided on the upper front surface of the main body exterior portion 1.

  As shown in FIG. 2, a bottomed cylindrical water tank 4 having an opening 4 a on the front surface is disposed in the main body exterior portion 1. As shown in FIGS. 3 and 4, the water tank 4 is elastically supported in the main body exterior portion 1 by a first suspension device 7 a and a second suspension device 7 b made of a tension spring.

  An angle 29 a is attached to the inner wall of the main body exterior portion 1 at the front upper portion of the water tank 4, and an angle 29 b is attached to the back wall of the main body exterior portion 1 at the upper portion. Angles 30 a and 30 b are fixed to the front surface and the back surface of the water tank 4. And the 1st suspension apparatus 7a is hung between the angle 29a and the angle 30a, and the front part of the water tank 4 is suspended in two places of right and left by the 1st suspension apparatus 7a. Similarly, the second suspension device 7b is hooked between the angle 29b and the angle 30b, and the rear portion of the water tank 4 is suspended at two places on the left and right by the second suspension device 7b. The first and second suspension devices 7a and 7b are attached symmetrically with inclinations of angles θ1 and θ2 with respect to the vertical direction, respectively. Thereby, the water tank 4 can be centered with respect to the sliding in the left-right direction. The angles 30a and 30b may be integrally formed with the water tank 4.

  The water tank 4 is supported on the bottom of the main body exterior portion 1 by an attenuation device including dampers 8a and 8b. Dampers 8 a are attached to the left and right two locations on the front side of the water tank 4, and dampers 8 b are attached to the left and right two locations on the rear side of the water tank 4. Thereby, the oscillation of the water tank 4 is attenuated.

  As shown in FIG. 2, a cushioning material 28 made of felt, rubber or the like is fixed to the back wall of the main body exterior portion 1. Thereby, when the water tank 4 slides in the front-rear direction, generation of noise due to a collision between the water tank 4 and the back wall of the main body exterior portion 1 is prevented.

  A drum 5 is disposed in the water tank 4. A rotating shaft 5e is fixed to the drum 5, and the rotating shaft 5e is supported by a bearing 6 integrated with the water tank 4 through a motor case 9a, so that the drum 5 is rotatable. A rotor 9b is fixed to the rotating shaft 5e, and a stator 9c is fixed in the motor case 9a. The rotor 9b and the stator 9c constitute a motor 9 that drives the drum 5. The rotational drive of the motor 9 is controlled by a control unit composed of a microcomputer 64 (to be referred to as a microcomputer hereinafter). In the present embodiment, a three-phase 20-pole DC brushless motor is used as the motor 9.

  The rotor 9b of the motor 9 is rotatably held concentrically within the stator 9c. The rotor 9b is shown in FIG. The rotor core 71 is composed of laminated steel plates. A permanent magnet 72 is disposed between the salient poles 71 </ b> A of the rotor core 71. By reversing the arrangement of the N pole 72N and the S pole 72S of the adjacent permanent magnets 72, the salient pole 71A of the rotor core 71 alternates between the N pole 71N and the S pole 71S. By adopting such a configuration, it is possible to obtain a higher magnetic force than a configuration in which a permanent magnet is attached to the rotor core 71 in a circumferential shape.

  A stator 9c provided in the motor cover 9a is shown in FIG. The stator 9c has 24 poles, and the stator core 73 is formed of laminated steel plates in the same manner as the rotor core 71. A winding 74 is wound around the stator core 73 by a concentrated winding method. Instead of the concentrated winding method, for example, the winding 74 may be wound around the stator core 73 by a lap winding method. Further, a hall sensor (not shown in FIG. 6) is fixedly provided on the motor cover 9a between the rotor 9b and the stator 9c, and detects the N pole and the S pole of the salient pole 71A of the rotor core 73. .

  The motor 9 has 20 poles, and the salient poles 71A of the rotor core 71 each have 10 N poles and 10 S poles. However, the number of poles is not limited to that of the present invention. Further, the configuration of the rotor is not limited to the present invention. For example, a permanent magnet may be circumferentially attached to the rotor.

  In the drum type washing machine of the present embodiment, a direct drive system in which the drum 5 and the motor 9 are directly fixed is used. Thereby, the load torque fluctuation of the drum 5 can be accurately transmitted to the motor 9 with little time delay.

  A small hole 5 a is provided in the entire peripheral wall of the drum 5. During washing, washing water can flow between the water tank 4 and the drum 5 through the small holes 5a. A baffle 5 b protrudes from the inner wall surface of the drum 5. The baffle 5b catches and lifts the laundry by the rotation of the drum 5, and the laundry is dropped into the washing liquid by its own weight, so that washing is performed.

  A liquid balancer 5d is provided on the outer peripheral edge of the opening 5c on the front surface of the drum 5. A liquid such as salt water is sealed in the liquid balancer 5d, and the fluid moves when the drum 5 rotates so as to eliminate the movement of the center of gravity due to the deviation of the laundry and the washing liquid. The liquid balancer 5d may be provided on the inner peripheral edge of the drum 5.

  The rotation axis yy of the drum 5 is inclined so that the back side of the drum 5 is lowered by an angle θ with respect to the horizontal axis. As a result, when the user stands on the front side of the drum type washing machine and puts in and out the laundry, the depth of view of the drum 5 is improved, and the laundry can be easily put in and out.

  A packing 10 made of an elastic material such as rubber or resin is attached to the periphery of the laundry input port 1a and the opening 4a of the water tank 4 so as to form a passage. When the door 3 is closed, the inner peripheral edge 10 a of the packing 10 is in close contact with the peripheral edge of the door 3. Thereby, waterproofing during a washing operation can be performed. Further, the packing 10 has a stretchable structure such as a bellows, and the packing 10 bends and follows as the water tank 4 swings.

  A water supply pipe 12 connected to a water pipe is disposed in the upper part of the main body exterior portion 1. When the water supply valve 13 provided in the middle of the water supply pipe 12 is opened, tap water is supplied into the water tank 4 from the water supply nozzle 15 attached to the packing 10 via the detergent case 14.

  The drainage duct 16 led out from the bottom surface of the water tank 4 is provided with a connection case 17 and a drainage pump 18 in which a lint filter 17a is provided in the middle of the pipeline, and the washing liquid from the water tank 4 is supplied to the outside of the main body exterior portion 1. Drain into. The yarn waste filter 17a is configured by, for example, forming a resin in a lattice shape or forming fine fibers in a bag shape, and accumulates the yarn waste and the like in the washing liquid. The lint filter 17 a is detachably mounted in the connection case 17 and can be removed from the lower front portion of the main body exterior portion 1.

  A water level sensor 23 is provided on the upper part of the connection case 17 from the air trap 22 through the dynamic pressure pipe 21. In the water level sensor 23, the magnetic body is moved in the coil in accordance with the pressure change in the air trap 22. The resulting inductance change in the coil is detected as a change in oscillation frequency, and the water level in the water tank 4 is detected. In addition, it is good also as a structure which provides the circulation path which flows in / out to a water tank, and arrange | positions the drying unit which consists of a ventilation fan and a heater in the middle of this circulation path.

  And the control apparatus 2 which controls operation | movement of the drum-type washing machine mentioned above is distribute | arranged to the back surface of the operation panel 11. FIG. As shown in FIG. 7, the control device 2 includes a microcomputer 64, an EEPROM 65, an inverter circuit (inverter unit) 57, and drive circuits 62 and 66, and controls the motor 9 as well as the water supply valve 13 and the drainage pump 18. .

  The EEPROM 65, which is a non-volatile memory, stores programs such as the contents of operations in each process such as washing, rinsing, and dehydration, and the execution order of the processes (that is, the processing course). The microcomputer 64 controls the opening / closing of the water supply valve 13 and the on / off switching of the drainage pump 18 via the drive circuit 66 according to the program, and also controls the inverter circuit 57 via the drive circuit 62. It should be noted that programs such as the operation contents of each process and the execution order of the processes may be stored not in the EEPROM 65 but in a memory inside the microcomputer 64.

  When a signal such as a laundry reservation is input from the operation panel 11, the microcomputer 64 executes the operation of each process based on the water level signal input from the water level sensor 23 according to the program, and displays the progress of the operation. Is output to the operation panel 11 to notify the display or the like.

  Here, the microcomputer 64, the inverter circuit 57, and the drive circuit 62 constitute the motor drive device of the present invention. The rotation control of the motor 9 by this motor drive device will be described in detail.

  The AC voltage output from the commercial power supply 53 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 respectively connected in parallel with diodes 60a to 60c and 61a to 61c. Connection points a, b, and c of the transistors 58a to 58c and the transistors 59a to 59c are connected to stator coils Lu, Lv, and Lw of each phase (U phase, V phase, and W phase) of the motor 9. The bases of the transistors 58 a to 58 c and 59 a to 59 c are connected to the drive circuit 62.

  The motor 9 includes hall sensors 63a, 63b, and 63c as rotor position detection units that detect the rotational position of the rotor 9b. 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 performs PWM chopping and amplification of 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. Similarly, the drive signals P3 and P4 are supplied to the bases of the transistors 58b and 59b, respectively, and the drive signals P5 and P6 are supplied to the bases of the transistors 58c and 59c, respectively.

  The microcomputer 64 sends drive signals P1 to P6 to the drive circuit 62 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. The motor 9 is driven to rotate.

  Here, feedback control performed when the motor 9 is rotationally driven will be described. First, voltage waveforms applied to the motor 9 by the inverter circuit 57 will be described with reference to FIG. (B) in FIG. 8 is applied to the U-phase stator winding Lu of the motor 9 when the motor 9 is steadily driven at a constant rotational speed based on the rotor position signals Hu, Hv, Hw shown in (a). Voltage Eu (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 referred to as 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 has a PWM (Pulse Width Modulation) waveform as shown in FIG. This waveform is substantially equivalent to the applied voltage Eu shown in FIG.

  Further, as shown in FIG. 8B, 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. Thus, by applying a sinusoidal voltage with a phase shift to each phase of the motor 9, the rotor 9b of the motor 9 rotates in the forward direction.

  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.

  Although the drum 5 is rotated by the motor torque TM generated by the motor 9, the magnitude of the load torque TL applied to the motor 9 varies in one rotation depending on the position of the laundry. For example, by continuously driving the motor 9 at a predetermined low speed, when the drum 5 rotates at a low speed, the centrifugal force applied to the laundry is smaller than the gravity, and the laundry falls while the rotation is rising, the load torque TL changes greatly. To do.

  The motor drive device detects the state of the laundry accommodated in the drum 5 and controls the drive of the motor 9 in accordance with the load torque applied to the motor 9 that fluctuates due to the state change. A rotor position detection unit is used as the stored item state detection unit for detecting the state of the laundry, and the state change of the laundry, that is, the rotation, based on the rotor position detection interval obtained from the position signal of the rotor 9b. The position of the laundry in the drum 5 is detected.

  The reason why the position of the laundry can be estimated from the rotor position detection interval information based on the position signal of the rotor position detection unit will be described with reference to FIG. In addition, FIG. 11 is a case where the drive control of the motor 9 is performed so that it may become a fixed motor torque irrespective of the position of the laundry.

  The load torque becomes the largest while the laundry is being lifted up in the washing liquid (first state), and then the laundry is lifted onto the washing liquid and stuck to the drum 5 by the action of centrifugal force. By increasing, the load torque decreases (second state), and the load torque becomes minimum when the laundry falls due to the action of gravity (third state).

  Here, assuming that the moment of inertia JR of the rotating shaft system, the rotational speed NR of the rotating shaft system, and the residual torque ΔT, the equation of motion at this time is shown as follows.

JR · (dNR / dt) = TM−TL = ΔT (1)
When attention is paid to the expression (1), in the rotating shaft system, the influence of the residual torque appears as the rotational speed fluctuation of the rotating shaft, which causes the washing machine to vibrate.

  When the motor torque TM and the load torque TL are in the relationship as shown in FIG. 11A, the rotational acceleration dNR / dt is as shown in FIG. 11B, and the rotational speed NR, which is the time integral of the rotational acceleration, is shown in FIG. c).

  Here, the rotor position detection interval will be described with reference to FIG. The change of the position signal Hu from the high level to the low level or from the low level to the high level is every electrical angle of 180 degrees, and the position signals Hv and Hw are the same. Here, since the position signals Hu and Hv change with a phase difference of an electrical angle of 240 degrees and the position signals Hu and Hw change with a phase difference of an electrical angle of 120 degrees, the change in the level of any position signal is an electrical angle. It occurs every 60 degrees, and this occurrence interval time is taken as the rotor position detection interval. Accordingly, there are six position signals output from the rotor position detection unit in an electrical angle of 360 degrees, and there are 60 position signals because the number of poles of the motor 9 is 20 during one rotation of the motor.

  The position signal generation interval corresponds to the rotational speed NR. When the rotational speed NR is high, the rotor position detection interval is short, and when the rotational speed NR is slow, the rotor position detection interval is long. Therefore, it becomes as shown in FIG.

  As shown in FIG. 11, the rotational speed corresponding to the rotor position detection interval is calculated by time integration of the rotational acceleration. This rotational acceleration changes according to the increase or decrease of the load torque applied to the motor. Therefore, the load torque can be estimated from the rotor position detection interval. Since the load torque changes according to the position of the laundry, the position of the laundry can be detected based on the rotor position detection interval.

  That is, the container state detection unit divides one rotation of the motor 9 into a plurality of sections based on the position signal from the rotor position detection unit, detects the rotor position detection interval for each section, and detects the position of the laundry. . The sections to be divided are, for example, first to third states shown in FIG.

  When the laundry lifted by the rotation of the drum 5, which is the third state, falls, the load torque decreases rapidly and becomes the minimum. At this time, since the rotational acceleration increases rapidly and increases, the rotational speed increases and the rotor position detection interval decreases. Thus, when the rotor position detection interval becomes shorter, it can be determined that the laundry is falling. In addition, when there is laundry in the washing liquid, which is the first state, the load torque suddenly increases and then gradually decreases. At this time, the rotational acceleration does not change for a while after it decreases. The rotation speed does not change after it has increased. The rotor position detection interval is rapidly shortened, and thereafter the change is reduced. Thus, when the rotor position detection interval changes, it can be determined that the laundry is being lifted up in the washing liquid. In addition, when the laundry in the second state is lifted onto the washing liquid, the load torque gradually decreases from the maximum value. At this time, the rotational acceleration gradually increases from no change, and the rotational speed decreases once and gradually increases. The rotor position detection interval becomes longer and then gradually becomes shorter. Thus, when the rotor position detection interval changes, it can be determined that the laundry has been lifted onto the washing liquid.

  As described above, the microcomputer 64 determines the position of the laundry from the rotor position detection interval information. Then, in order to change the motor torque according to the fluctuation of the load torque, as shown in FIG. 9, the amplitude of the sinusoidal applied voltages Eu, Ev, Ew supplied to the motor 9 according to the change in the position of the laundry is set. Control.

  As shown in FIG. 10, when the amplitude of the applied voltage Eu is substantially increased, the motor torque TM is increased, and when the amplitude of the applied voltage Eu is decreased, the motor torque TM is also decreased. The same applies to the applied voltages Ev and Ew.

  As described above, by controlling the amplitudes of the applied voltages Eu, Ev, and Ew supplied to the motor 9 according to the change in the position of the laundry, the motor torque TM can be brought close to the load torque TL. That is, when the load torque TL is large, the amplitudes of the applied voltages Eu, Ev, Ew are increased so that the motor torque TM increases. When the load torque TL is small, the amplitudes of the applied voltages Eu, Ev, Ew are made small so that the motor torque TM becomes small.

  As a result, the motor torque TM and the load torque TL have a relationship as shown in FIG. 9A, and the residual torque becomes small. Therefore, the rotation fluctuation of the drum is suppressed, and the vibration of the washing machine can be reduced. At this time, as shown in FIG. 9B, the fluctuation of the rotational acceleration dNR / dt is also smaller than that in FIG. Along with this, as shown in FIG. 9C, the fluctuation of the rotational speed NR also becomes smaller than that in FIG. Further, as shown in FIG. 9 (d), the fluctuation of the rotor position detection interval is also smaller than that in FIG. 11 (d). However, the fluctuation of the rotor position detection interval does not completely disappear, and the tendency of this fluctuation does not change. Therefore, the position of the laundry can be detected continuously from the rotor position detection interval, and the motor 9 can be driven and controlled. is there.

  Note that the current supplied to the motor 9 may be controlled instead of controlling the applied voltages Eu, Ev, Ew. By controlling the amplitude of the current supplied to the motor 9 to be increased or decreased according to the change in the position of the laundry, the motor torque can be increased or decreased, and the residual torque can be decreased. .

  Further, a motor current detection unit (not shown) that detects a current supplied to the motor 9 is provided. The motor current detection unit detects a motor current value by interposing a resistor between the inverter circuit 57 and the motor 9. The control unit 64 limits the maximum amplitude value of the applied voltages Eu, Ev, Ew supplied to the motor 9 based on the detected motor current value. Thereby, it is possible to prevent an excessive current from flowing through the motor 9 and the inverter circuit 57 and to prevent the motor 9 and the inverter circuit 57 from being broken or deteriorated.

  Alternatively, a direct current detection unit (not shown) for detecting a direct current flowing through the inverter circuit 57 is provided. The direct current detection unit detects a direct current value of the inverter circuit 57 by interposing a resistor between the inverter circuit 57 and the rectifier circuit 55. The control unit 64 limits the maximum amplitude value of the sinusoidal applied voltages Eu, Ev, Ew supplied to the motor 9 based on the detected direct current value. Thereby, it is possible to prevent an excessive current from flowing through the motor 9 and the inverter circuit 57 and to prevent the motor 9 and the inverter circuit 57 from being broken or deteriorated.

  In addition, this invention is not limited to the said embodiment, Of course, many corrections and changes can be added to the said embodiment within the scope of the present invention. In the embodiment described above, the rotor position detection interval is used for the laundry position detection as the stored item state detection unit. However, a motor current detection unit that detects a current to be supplied to the motor is provided, and based on the detected motor current value. The position of the laundry may be detected. Or you may provide the direct current detection part which detects the direct current which flows into an inverter circuit, and may detect the position of the laundry based on the detected direct current value. The rotor position can be estimated from the change period of the amplitude of these current values, and the position of the laundry can be detected.

  In addition, as the container state detection unit, an optical element such as a CCD camera or an infrared sensor may be used to detect the position of the laundry based on the image information. Furthermore, if the amount of laundry is large, the laundry may overlap, and not only the position but also the distribution of the laundry affects the load torque. Therefore, the laundry state such as the position and distribution of the laundry may be detected from the image information obtained by the optical element. And the drive control of a motor is performed according to the state change of this laundry.

  In addition to the drum type washing machine, the motor drive device of the present invention may be used as a motor drive unit for a washing machine or a drum type dryer in which a rotating container rotates around a vertical axis. You may use for the electric equipment rotated and driven with a motor like the stirring apparatus which accommodates and stirs a body and a granule.

The perspective view of the drum type washing machine of the present invention Side view of drum type washing machine Front view of drum-type washing machine Rear view of drum-type washing machine Diagram showing motor rotor Diagram showing motor stator Block diagram of a control device having a motor drive device The figure which shows the applied voltage to the motor based on the position signal of a rotor position The figure which shows the change of the load torque, motor torque, rotational acceleration, rotational speed, and rotor position detection interval when drive control of the motor is performed according to the state of the laundry The figure which shows the relationship between the voltage applied to the motor and the motor torque The figure which shows the change of the load torque, motor torque, rotational acceleration, rotational speed, and rotor position detection interval when not performing drive control of the motor according to the state of the laundry

Explanation of symbols

2 Control device 5 Drum 9 Motor 57 Inverter circuit 63a
~ 63c Hall sensor 64 Microcomputer

Claims (2)

A motor that accommodates the contents and rotationally drives a rotating container that rotates about a horizontal axis or an inclined axis; a rotor position detector that detects a rotational position of a rotor of the motor; and a centrifugal force generated by the rotation of the rotating container; comprising a housing thereof state detector for detecting the state of the contained object which changes by the action of gravity, and a control unit for driving and controlling the motor based on the position signal from the rotor position detecting unit, the contained goods state detection The unit detects a change in state in which the object lifted by the action of centrifugal force falls due to the action of gravity based on a rotor position detection interval based on a position detection signal of the rotor position detection part, and the control part A motor driving device that controls a current or voltage supplied to the motor in accordance with a change in state of an object. A washing machine comprising the motor driving device according to claim 1 .

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