JP2004105585A - Washer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To stop a motor in a short time by eliminating the problem as braking operation even if the rise of source voltage and a load change applied to the motor are caused by quickly avoiding a state of rotating the motor in the inverse direction because braking force is too large when stopping the motor by the braking operation in a washer for driving the motor by an inverter circuit. <P>SOLUTION: The motor 5 is driven by converting DC electric power of a rectifying circuit 3 connected to an AC power source 1 into AC electric power by the inverter circuit 4, and a rotor position of the motor 5 is detected by a rotor position detecting means 6, and the inverter circuit 4 is controlled by a control means 9. The control means 9 stops the braking operation when detecting that the motor 5 rotates in the inverse direction of the direction for performing the braking operation by the rotor position detecting means 6 in the braking operation of the motor 5. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a washing machine that drives a motor by an inverter circuit.
[0002]
[Prior art]
2. Description of the Related Art In recent years, there has been proposed an apparatus in which a motor of a washing machine is driven by an inverter circuit to improve motor performance, and the motor is brake-operated by the inverter circuit.
[0003]
Conventionally, this type of washing machine drives a stirring blade or a dewatering tub at a lower portion of a washing tub by a brushless motor, and detects a rotor position by a motor position detecting means to control an applied voltage and a phase command to the motor. Thus, the dehydration brake is controlled (for example, see Patent Document 1).
[0004]
[Patent Document 1]
JP-A-11-275889
[Problems to be solved by the invention]
However, in such a conventional configuration, when the dehydration tub is stopped in the final stage of the dehydration brake control, a force greater than the braking force required for the stoppage due to a load state in the dehydration tub or an increase in the power supply voltage. Occurs, the rotation is made in the opposite direction beyond the stop state, and there is a problem that the dehydration tank does not stop.
[0006]
The present invention solves the above-mentioned conventional problems, and when a motor is stopped by a braking operation, a state in which a braking force is too large and a motor rotates in a reverse direction is quickly avoided, and a power supply voltage rise and a motor It is an object of the present invention to enable the motor to be stopped in a short time without any problem as a braking operation even if the load fluctuation or the like occurs.
[0007]
[Means for Solving the Problems]
In order to achieve the above object, the present invention converts a DC power of a rectifier circuit connected to an AC power supply into AC power by an inverter circuit to drive a motor, and detects a rotor position of the motor by a rotor position detecting means. The circuit is configured to be controlled by the control means, and the control means detects, during the braking operation of the motor, that the rotor position detection means detects that the motor is rotating in the direction opposite to the direction in which the motor is performing the braking operation. The braking operation is stopped.
[0008]
Accordingly, when the motor is stopped by the braking operation, a state in which the braking force is too large and the motor rotates in the reverse direction can be quickly avoided, and a rise in the power supply voltage, a load change on the motor, and the like can be prevented. Even if it occurs, the motor can be stopped in a short time without any problem as a braking operation.
[0009]
BEST MODE FOR CARRYING OUT THE INVENTION
The invention according to claim 1 of the present invention provides an AC power supply, a rectifier circuit connected to the AC power supply, an inverter circuit that converts DC power of the rectifier circuit into AC power, and a motor driven by the inverter circuit. A rotor position detecting means for detecting a rotor position of the motor, and a control means for controlling the inverter circuit, wherein the control means controls the motor by the rotor position detecting means during braking operation of the motor. The direction of the braking operation is such that when it is detected that the motor is rotating in the opposite direction, the braking operation is stopped.When the motor is stopped by the braking operation, the braking force is too large and the motor is stopped. It is possible to quickly avoid a situation such as rotating in the reverse direction, and even if a power supply voltage rises or a load change applied to the motor occurs, there is no problem as a braking operation. It is possible to stop the motor in a short time duck.
[0010]
According to a second aspect of the present invention, in the first aspect of the present invention, the control means performs the braking operation by delaying the motor current phase from the induced voltage phase of the motor. A braking torque can be generated in the motor, and the motor can be stopped in a short time while improving the reliability of the inverter circuit.
[0011]
According to a third aspect of the present invention, in the first aspect of the present invention, when the rotation speed of the motor detected by the rotor position detection unit is equal to or less than a predetermined rotation speed during the braking operation, When it is detected that the motor is rotating in the direction opposite to the direction of the braking operation, the braking operation is stopped, and noise and the like are superimposed on the output signal from the rotor position detection means in the initial stage of the braking operation. However, even if the output signal does not reach the correct value, it does not judge in which direction the motor is rotating in the normal or reverse direction. Can be stopped.
[0012]
According to a fourth aspect of the present invention, in the first aspect of the invention, the control means rotates the motor in a direction opposite to the direction in which the motor is performing the braking operation by the rotor position detecting means during the braking operation. When it is detected that the motor is stopped, the braking operation is stopped, and thereafter, the washing operation is restarted by detecting that the motor is surely stopped by the rotor position detecting means. After that, it is detected that the motor that is rotating due to inertia has stopped steadily, and the motor is driven again from this stopped state, preventing the inverter circuit from overcurrent or the motor not rotating as intended. It is possible to provide a washing machine that satisfies the basic operation while improving the reliability of the inverter circuit.
[0013]
According to a fifth aspect of the present invention, in the first aspect of the present invention, the washing and dewatering tub rotatably provided in the outer tub and the stirring blade rotatably disposed in the washing and dewatering tub are provided. The washing and dewatering tub and the stirring blade are driven by a motor, and the control means performs a dehydration braking operation for stopping the washing and dewatering tub, the rotor and position detecting means causes the washing and dehydration tub to perform a braking operation. The direction in which the spinning is performed in the opposite direction is to stop the spin-drying braking operation when it is detected that the spinning is rotating in the opposite direction. Since it is possible to quickly avoid a state in which the spin-drying tub rotates in the opposite direction, even if a power supply voltage rises or a load fluctuation in the spin-drying tub occurs, there is no problem as a braking operation. Moreover, the washing and dewatering tub must be stopped in a short time. It can be.
[0014]
According to a sixth aspect of the present invention, in the first aspect of the invention, by rotating the washing and dewatering tub, the washing water can be sprinkled into the washing and dewatering tub from between the outer tub and the washing and dewatering tub. As described above, when the control unit detects that the washing and dewatering tub is rotating in the opposite direction to the direction in which the washing and dewatering tub is performing the braking operation during the braking operation of the washing and dewatering tub by the rotor position detecting unit. When the washing and dewatering tub is stopped by the braking operation, a state in which the braking force is too large and the washing and dewatering tub rotates in the opposite direction is quickly avoided. Therefore, even if the inertia force fluctuates greatly due to an increase in the power supply voltage or a load fluctuation in the washing and dewatering tub, particularly due to the effect of the washing water, there is no problem as a braking operation, and the washing and dewatering tub can be performed in a short time. Can be stopped.
[0015]
【Example】
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0016]
(Example 1)
As shown in FIG. 1, an AC power supply 1 applies AC power to a rectifier circuit 3 via a line filter 2 and converts the rectifier circuit 3 into DC power. The rectifier circuit 3 constitutes a voltage doubler rectifier circuit. When the AC power supply 1 has a positive voltage, the capacitor 3b is charged by the full-wave rectifier diode 3a, and when the AC power supply 1 has a negative voltage, the capacitor 3c is charged and connected in series. A doubled DC voltage is generated at both ends of the capacitors 3b and 3c, and the doubled DC voltage is applied to the inverter circuit 4.
[0017]
The inverter circuit 4 is constituted by a three-phase full-bridge inverter circuit comprising six power switching semiconductors and an anti-parallel diode, and usually incorporates a power transistor (similar to an IGBT), an anti-parallel diode, a drive circuit therefor and a protection circuit. It consists of an intelligent power module (hereinafter referred to as IPM). The motor 5 is connected to the output terminal of the inverter circuit 4, and the rotary blade 23 or the washing and dewatering tub 18 is driven by the motor 5 as shown in FIG.
[0018]
The motor 5 is constituted by a DC brushless motor. As shown in FIG. 2, the relative position (rotor position) between the permanent magnet 51 and the stator 52 constituting the rotor 50 is detected by the rotor position detecting means 6. The rotor position detecting means 6 is usually composed of three Hall ICs (6a, 6b, 6c) and detects a position at every 60 electrical degrees.
[0019]
The control circuit 7 controls the inverter circuit 4 and the switching means 8, and controls the IPM of the inverter circuit 4 by the control means 9 constituted by a microcomputer and the output signal of the control means 9 to rotate the motor 5. An inverter driving circuit 10 for controlling the switching means 8; a switching means driving circuit 11 for controlling the switching means 8; It comprises a detection circuit 13.
[0020]
Further, the control circuit 7 controls the switching means 8 to control the operations of the water supply valve 14, the drainage valve 15, the clutch 16, the lid lock device 17, and the like, and controls a series of steps of washing, rinsing, and dewatering.
[0021]
As shown in FIG. 2, the water supply valve 14 supplies tap water to an outer tub 19 provided outside the washing and dewatering tub 18. The opening and closing of the lid 20 that can be opened and closed is prohibited during the dehydrating operation, and is constituted by a solenoid and a lever. The drain valve 15 drains the washing water in the outer tub 19.
[0022]
The clutch 16 connects the output of the motor shaft 53 of the motor 5 to the drive shaft 22 of the stirring blade 23 rotatably provided on the inner bottom of the washing and dewatering tub 18 via the speed reduction mechanism 21, or The motor 5 drives the washing / dewatering tub 18 or the stirring blade 23 by switching between directly connecting to the drive shaft of the dewatering tub 18. The outer tub 19 is elastically suspended from an outer frame 25 via a suspension 24.
[0023]
The switching means 8 is connected between the lines L1 and L2 of the AC power supply 1 to control an applied voltage, and is constituted by a relay, a bidirectional thyristor, or the like, and includes a water supply valve 14, a drain valve 15, a clutch 16, a lid This controls the lock devices 17 respectively.
[0024]
The inverter circuit 4 is configured as shown in FIG. 3, and includes a U-phase switching unit 40A, a V-phase switching unit 40B, and a W-phase switching unit 40C.
[0025]
The U-phase switching unit 40A includes a pair of transistors (IGBT) including an upper arm transistor 41a and a lower arm transistor 41a ′, antiparallel diodes 42a and 42a ′ connected in antiparallel to the respective IGBTs, and an upper arm transistor 41a. An upper arm driving circuit 43a for driving, a lower arm driving circuit 43a 'for driving the lower arm transistor 41a', a current limiting resistor 44a, a bootstrap diode 45a, a bootstrap capacitor 46a, and a lower arm driving circuit. It is composed of a circuit capacitor 47a. Since the V-phase switching unit 40B and the W-phase switching unit 40C have the same configuration, the description is omitted.
[0026]
The input signal Up of the upper arm drive circuit 43a and the input signal of the lower arm drive circuit 43a 'are Un, and B3 is a power supply of the upper arm drive circuit 43a and the lower arm drive circuit 43a' and is usually connected to a 15V power supply. When a drive signal is applied to the lower arm drive circuit 43a ', the lower arm transistor 41a' conducts, and the bootstrap capacitor 46a is charged from the power supply B3 via the current limiting resistor 44a and the bootstrap diode 45a. Therefore, when the upper arm transistor 41a is driven, before the lower arm transistor 41a 'is driven and the bootstrap capacitor 46a is charged, the inverter circuit 4 is operated and the motor 5 is driven.
[0027]
When the inverter circuit 4 is stopped, the bootstrap capacitor 46a is not charged, and the upper arm drive circuit 43a cannot operate, so that the upper arm transistor 41a does not conduct. Normally, a power supply voltage drop detection circuit is built in the upper arm drive circuit 43a, so that the IGBT cannot be made conductive when the bootstrap voltage is lower than a predetermined value.
[0028]
FIG. 4 shows the waveform relationship of each part of the sine wave drive by the PWM control. The edge signals of the output signals H1, H2, H3 of the rotor position detecting means 6 change every 60 degrees, and 360 degrees from each part state signal. The angle divided into six can be determined. A high edge at which the signal H1 changes from low to high is shown as a reference electrical angle of 0 degree, and the U-phase winding induced voltage Ec of the motor 5 has a waveform delayed by 30 degrees from the reference signal H1. The maximum efficiency can be obtained by making the phases of the U-phase motor current Iu and the motor induced voltage Ec the same.
[0029]
In FIG. 4, the U-phase motor current Iu has a waveform slightly advanced from the U-phase winding induced voltage Ec, and the motor applied voltage Vu has a waveform advanced by 30 degrees from the U-phase winding induced voltage Ec.
[0030]
vc is a sawtooth carrier signal generated in the inverter circuit 4, and vu is a sinusoidal U-phase control voltage and generates a PWM signal Up in the inverter circuit 4 by comparing the carrier signal vc with the U-phase control voltage vu. Then, it is added as a control signal for the U-phase upper arm transistor of the inverter circuit 4. ck is a synchronizing signal of the carrier signal vc, and is an interrupt signal when the carrier counter counts up and overflows.
[0031]
A point in time when the output signal H1 of the rotor position detecting means 6 changes from low to high is defined as a reference electric angle of 0 degree, and electric angles such as 30 degrees, 90 degrees, and 150 degrees are obtained from the output signals H1, H2, and H3 of the rotor position detecting means 6. And the electrical angle θ is estimated from the rotation cycle except for every 60 degrees.
[0032]
FIG. 5 shows waveforms at the time of a braking operation for detecting an electrical angle from an output signal of the rotor position detecting means and controlling a voltage applied to the motor and a phase command. The timing chart which brakes the motor 5 by flowing is shown. In the case of sine wave drive, torque can be controlled by controlling the phase of the motor current and the induced voltage, so not only can torque be reduced to reduce vibration, but torque control can also be compared to square wave drive. It is advantageous.
[0033]
Generally, the motor output P is P = Ec × I × cos α, where the induced voltage Ec, the motor current I, and the phase difference α between the induced voltage Ec and the motor current are represented. Therefore, if the phase difference α is controlled to 90 degrees or more, a negative torque is generated, that is, a braking operation is performed.
[0034]
By controlling the motor current I and the phase difference α, the braking force can be controlled. Since it is difficult to directly control the motor current I and the phase difference α (however, it becomes possible by performing vector control), the applied voltage G corresponding to the rotation speed N of the motor 5 and the phase command αd (induced The motor current I and the phase difference α with respect to the voltage (the phase of the applied voltage with respect to the voltage) are experimentally obtained, and the braking force is controlled by this.
[0035]
In order to obtain a large braking force within a range not exceeding the rated current of the inverter circuit 4 (IGBT), as shown in FIG. 6, the applied voltage G and the phase command αd corresponding to the optimum motor rotation speed N were experimentally tested. Ask for it. At this time, a particular problem is the setting of a braking force for stopping the motor 5 (in FIG. 6, the rotation speed is 100 r / min or less). If the braking force is small, the time required to stop the motor 5 will be unnecessarily long. If the braking force is too large, the motor 5 will rotate in the opposite direction past the stopped state because of a negative torque.
[0036]
When the washing and dewatering tub 18 is brought into a stopped state by braking (braking) operation, a braking force is set so as to balance the inertia force of the washing and dewatering tub 18 itself and the laundry in the washing and dewatering tub 18. If the clothes in the washing and dewatering tub 18 are imbalanced or the power supply voltage rises, the balance between the inertial force and the braking force is lost, and it takes a long time to stop, or in the opposite direction. It may rotate and stop.
[0037]
There is no problem as to the operation of the washing machine that the time until the stop is slightly longer, but there is a problem as a basic operation of the washing machine as it does not stop after rotating in the opposite direction. Therefore, it is determined from the output signal from the rotor position detecting means 6 in which direction the motor is rotating in the normal or reverse direction. If the motor is rotating in the reverse direction, the brake operation is stopped and the operation waits until the engine stops naturally. To do.
[0038]
As shown in FIG. 7, the output signal (output) from the rotor position detecting means 6 is different between when the motor is rotating in the forward (clockwise CW) direction and when the motor is rotating in the reverse (counterclockwise CCW) direction. Output patterns of the signals H1, H2, H3).
[0039]
When the motor is rotating in the normal rotation direction and the braking operation is to be stopped, a signal shown in FIG. 7A is output from the rotor position detecting means 6 before the stop. 7B, the output pattern of the output signals H1, H2, and H3 does not change because the rotor is not rotating), and when the rotor rotates in the reverse direction, the signal shown in FIG. I do.
[0040]
Further, when the braking operation is continued while the motor is rotating in the reverse direction, the correct applied voltage to the rotor position (as described above, the rotor position is detected by the output signal of the rotor position detecting means 6 and the induced voltage phase is detected). Since the phase of the applied voltage is estimated based on the induced voltage phase, if the output signal of the rotor position detecting means 6 outputs an unexpected value, the induced voltage phase cannot be estimated. Therefore, the correct applied voltage phase cannot be set naturally. ) Cannot be set, and the rotation of the motor 5 is not correct (for example, intermittent rotation).
[0041]
Next, the operation of the dewatering process will be described with reference to FIG. In step 300, the spin-drying process is started. In step 301, the lid lock device 17 is driven so that the lid 20 is not opened during the spin-drying process. Next, the routine proceeds to step 302, where the motor 5 is started. The rotation direction at the time of dehydration is the normal rotation direction (clockwise). As a method of starting control, rectangular wave driving or the like is performed to obtain more starting torque. After the motor is started, the process proceeds to step 303 to switch to sine wave driving.
[0042]
From step 304, rotation speed control is performed. In the case of the dehydration operation, as shown in FIG. 9, the rotational speed is increased stepwise with the target of the final rotational speed N3 (900 r / min) (N1: 160 r / min, N2: 220 r / min, N3: 900 r / min). min, t1: 5 s, t2: 20 s, t3: 80 s).
[0043]
In step 305, it is determined whether a first predetermined time t4 (dehydration time, for example, 5 minutes) has elapsed, and the dehydration operation is continued until the predetermined time elapses. After the elapse of a predetermined time and the dehydration operation is completed, the process proceeds to step 306 to stop the washing and dehydration tub 18, and the brake control shown in FIG. 5 is performed. Further, at this time, as shown in FIG. 6, the applied voltage G and the phase command αd are controlled according to the rotation speed N of the motor 5.
[0044]
During the brake control, in step 307, the number of revolutions of the motor 5 is detected based on the output signal from the rotor position detecting means 6. The rotation speed can be detected from the cycle of the output signal of the rotor position detection means 6a. In step 308, it is determined whether or not the rotation speed of the motor 5 is equal to or lower than a predetermined rotation speed N4 (for example, 100 r / min). 314 is performed.
[0045]
The reason for performing the process of determining whether or not the rotation has stopped after detecting the predetermined rotation speed N4 or less is that an incorrect signal from the rotor position detection means 6 due to the influence of noise or the like (the rotation signal is rotating in the normal rotation direction, Is output), and the brake operation is terminated by believing this signal. As a result, the operation of the washing machine is not normal, and the lid lock 19 is released even though the washing machine is rotating at a high speed. Therefore, in order to avoid the unsafe state as much as possible, the processing in steps 307 to 308 is performed, and then the stop state is determined.
[0046]
At step 309, the output signal from the rotor position detecting means 6 is detected again. At step 310, it is determined whether or not the output signal has changed. It is determined that the water tank 18) is stopped. If it is determined that the motor 5 has stopped, the process proceeds to step 312. If it is determined that there is a change in the output signal, that is, if the motor 5 is rotating, it is determined in step 311 whether the motor 5 is rotating in the normal direction or the reverse direction (counterclockwise).
[0047]
As shown in FIG. 7, whether the rotation is normal or reversed can be determined from the output pattern of the rotor position detection means 6. Further, the reason why there is a possibility that the motor is rotating in the reverse direction is because the braking force is not correct and the vehicle passes the stop as described above.
[0048]
If it is determined that the motor is rotating in the normal rotation direction, the brake control needs to be further performed until the rotation is stopped. Therefore, the process returns to step 306 to continue the brake control. If it is determined that the motor is rotating in the reverse direction, the brake control needs to be stopped immediately. Therefore, the process proceeds to step 312, where all the transistors of the inverter circuit 4 are turned off, and the brake control ends.
[0049]
Even after the brake control ends, there is a possibility that the motor may coast by inertia. Therefore, in step 313, the output signal of the rotor position detecting means 6 is further detected. In step 314, the output signal does not change and the rotation by the inertial rotation stops. Continue to detect If it is detected that the operation has stopped, the process proceeds to step 314 to release the lid lock, and proceeds to the next step.
[0050]
As described above, according to the present embodiment, when the motor 5 is performing the braking operation, when the rotor position detecting unit 6 detects that the motor 5 is rotating in the direction opposite to the direction in which the motor 5 is performing the braking operation, the braking is performed. By stopping the operation, when the motor is stopped by the braking operation, a state in which the braking force is too large and the motor 5 rotates in the reverse direction can be avoided as quickly as possible. Even if a load change or the like occurs in the washing machine 5, a washing machine that stops the motor 5 in a short time without any problem as a braking operation can be provided.
[0051]
Further, by performing the braking operation by delaying the motor current phase from the induced voltage phase of the motor 5, a braking torque can be generated in the motor 5 with a small current, and the motor 5 can be improved while improving the reliability of the inverter circuit 4. Can be stopped in a short time.
[0052]
Further, when the rotation speed of the motor 5 detected by the rotor position detection means 6 is equal to or less than a predetermined rotation speed during the braking operation, when it is detected that the motor 5 is rotating in a direction opposite to the direction in which the braking operation is performed. By stopping the braking operation, noise or the like is superimposed on the output signal from the rotor position detecting means 6 in the initial stage of the braking operation, and even when the output signal does not become a correct value, the rotation speed of the motor 5 is high. In this case, since it is not determined in which direction the motor 5 is rotating in the forward or reverse direction, the motor 5 can be stopped accurately in a short time without being affected by noise or the like as much as possible.
[0053]
In the braking operation, when the rotor position detecting means 6 detects that the motor 5 is rotating in a direction opposite to the direction in which the braking operation is performed, the braking operation is stopped, and then the rotor position detecting means 6 6, by restarting the washing operation by detecting that the motor 5 has stopped reliably, it is detected that the motor 5 rotating by inertia has stopped reliably after the braking control has been stopped, and this stopped state Since the motor 5 is driven again, it is possible to prevent an overcurrent from flowing into the inverter circuit 4 and prevent the motor 5 from rotating as intended, thereby satisfying the basic operation while improving the reliability of the inverter circuit 4. A washing machine can be provided.
[0054]
Also, during the spin-drying braking operation for stopping the washing and spin-drying tub 18, when the rotor position detecting means 6 detects that the washing and spin-drying tub 18 is rotating in a direction opposite to the direction in which the braking and spinning is performed, By stopping the spin-drying braking operation, it is possible to quickly avoid a situation where the braking force is too large and the spin-drying tub 18 is rotated in the opposite direction when the spin-drying tub 18 is stopped by the braking operation. Therefore, even if a rise in the power supply voltage or a change in the load in the washing / dewatering tub 18 occurs, the braking / operation can be stopped without any problem in a short time.
[0055]
(Example 2)
The control means 9 shown in FIG. 1 drives the motor 5 to rotate the washing and spin-drying tub 18, thereby spraying the washing water into the washing and spin-drying tub 18 from between the outer tub 19 and the washing and spin-drying tub 18. During the braking operation of the washing and spin-drying tub 18, when the rotor position detecting means 6 detects that the washing and spin-drying tub 18 is rotating in the direction opposite to the direction of the braking operation, braking is performed. I try to stop driving. Other configurations are the same as those in the first embodiment.
[0056]
The operation of the above configuration will be described with reference to FIG. In step 400, the washing process is started, and in step 401, water supply to the washing / dewatering tub 18 is started. In step 402, it is determined whether or not water has been supplied to the set water level. If it is determined that the set water level has been reached, the flow proceeds to step 403, and a washing method for rotating the washing and spin-drying tub 18 is started. Thereafter, the processing of steps 403 to 415 is repeated until the time required for washing (second predetermined time: for example, 10 minutes) elapses, and the clothes in the washing and dewatering tub 18 are cleaned.
[0057]
In step 403, the motor 5 is started. The rotation direction at this time is the normal rotation direction (clockwise). As a method of starting control, rectangular wave driving or the like is performed to obtain more starting torque. After the motor is started, the process proceeds to step 404 to switch to sine wave drive, and the rotational speed is controlled from step 405.
[0058]
In the case where the washing and spin-drying tub 18 is rotated for washing, as shown in FIG. 11, the rotation speed is increased to the rotation speed Ns1 (for example, 150 r / min) over a time ts1 (for example, 15 seconds). The control is performed so that the rotation speed Ns1 is maintained until one predetermined time ts2 (for example, 30 seconds) elapses. In step 406, it is determined whether the first predetermined time ts2 has elapsed. If the predetermined time has elapsed, the washing and spin-drying tub 18 is temporarily stopped.
[0059]
The reason why the motor is not continuously rotated is that if the current is continuously supplied to the motor 5 (in particular, since this washing method requires a large torque, it is necessary to supply a large amount of current to the motor). In order to avoid an unsafe state from rising.
[0060]
In steps 406 to 415, processing for stopping the motor 5 (the washing and dewatering tub 18) is performed. In step 407, the brake control shown in FIG. 5 is performed. Further, at this time, as shown in FIG. 6, the applied voltage G and the phase command αd are controlled according to the rotation speed N of the motor 5. When the washing and dewatering tub 16 is rotated for washing, the control is performed from the rotation speed Ns1 until the washing is stopped.
[0061]
Stopping this state correctly is more difficult than stopping the washing and dewatering tub 16 in the dewatering process. The water in the washing and dewatering tub 16 becomes a large inertial force and acts to hinder the stop, and when trying to stop suddenly, the inertia of the washing water rotates the washing and dewatering tub 18 in the reverse direction. This is because force is generated. Therefore, if the optimum braking force is not applied, the washing and dewatering tub 18 will rotate in the reverse direction when stopped.
[0062]
The processing during the brake control, steps 408 to 415, are the same as the contents of steps 307 to 314 in the first embodiment, and therefore will not be described.
[0063]
If it is determined in step 415 that the washing / dewatering tub 18 has stopped, the process proceeds to step 416, and it is determined whether the washing time (second predetermined time) has ended. If not, the process returns to step 403. Perform the same operation. If it is determined that the second predetermined time has elapsed, the process proceeds to step 417, where the washing process is completed and the process proceeds to the next process.
[0064]
As described above, according to the present embodiment, the motor 5 is driven to rotate the washing and dewatering tub 18, so that the washing water is supplied from the space between the outer tub 19 and the washing and dewatering tub 18 into the washing and dewatering tub 18. When the washing and dewatering tub 18 is braked, the rotor position detecting means 6 detects that the washing and dewatering tub 18 is rotating in a direction opposite to the direction in which the braking and driving is performed. Since the braking operation is stopped, when the washing and dewatering tub 18 is stopped by the braking operation, a state in which the braking force is too large and the washing and dewatering tub 18 rotates in the opposite direction is quickly avoided. Therefore, even when the inertia force fluctuates greatly due to an increase in the power supply voltage or a load fluctuation in the washing and spin-drying tub 18, particularly the effect of the washing water, there is no problem as a braking operation, and the washing and dewatering can be performed in a short time. Stopping the aquarium 18 Kill.
[0065]
【The invention's effect】
As described below, according to the first aspect of the present invention, during the braking operation of the motor, the motor is rotating in the direction opposite to the direction of the braking operation by the rotor position detection means. When the braking operation is detected, the braking operation is stopped, and when the motor is stopped by the braking operation, a state in which the braking force is too large and the motor rotates in the reverse direction can be quickly avoided. Even if a rise or a load variation on the motor occurs, the motor can be stopped in a short time without any problem as a braking operation.
[Brief description of the drawings]
FIG. 1 is a partially block diagram of a washing machine according to a first embodiment of the present invention; FIG. 2 is a sectional view of the washing machine; FIG. 3 is a circuit diagram of an inverter circuit of the washing machine; Principal part waveform diagram when the motor of the washing machine is driven [FIG. 5] Principal part waveform diagram when the motor of the washing machine is braked [FIG. 6] (a) Motor rotation speed and applied voltage during braking control of the washing machine Relationship diagram (b) Relationship diagram between motor rotation speed and phase command during braking control of the washing machine (c) Relationship diagram between motor rotation speed and braking torque during braking control of the washing machine [FIG. 7] (a) Same Output signal waveform diagram of the rotor position detecting means during forward rotation of the washing machine (b) Output signal waveform diagram of the rotor position detecting means at the time of reverse rotation of the washing machine [FIG. 8] Flow chart in the dehydration process of the washing machine FIG. 9 is a time chart showing a change in the number of rotations of the motor during a spin-drying process of the washing machine. [Description of symbols is a time chart showing changes in motor speed in the wash step of the flow chart 11 the washing machine in the wash step of 施例 washing machine
Reference Signs List 1 AC power supply 3 Rectifier circuit 4 Inverter circuit 5 Motor 6 Rotor position detecting means 9 Control means

Claims (6)

An AC power supply, a rectifier circuit connected to the AC power supply, an inverter circuit for converting DC power of the rectifier circuit to AC power, a motor driven by the inverter circuit, and a rotor position for detecting a rotor position of the motor Detecting means, and control means for controlling the inverter circuit, wherein the control means, during the braking operation of the motor, by the rotor position detection means, the direction in which the motor is performing a braking operation, in the opposite direction A washing machine that stops the braking operation when it detects that it is rotating. The washing machine according to claim 1, wherein the control means performs the braking operation by delaying the motor current phase from the motor induced voltage phase. The control means detects that the motor is rotating in a direction opposite to the direction in which the motor is performing a braking operation when the rotation number of the motor detected by the rotor position detection means is equal to or less than a predetermined rotation number during the braking operation. The washing machine according to claim 1, wherein the braking operation is stopped. The control means stops the braking operation when the rotor position detecting means detects that the motor is rotating in the direction opposite to the direction of the braking operation during the braking operation, and thereafter, the rotor position detection 2. The washing machine according to claim 1, wherein the means restarts the washing operation by detecting that the motor has stopped. A washing and dewatering tub rotatably provided in the outer tub, and a stirring blade rotatably disposed in the washing and dewatering tub, wherein the washing and dewatering tub and the stirring blade are driven by a motor, and control means is provided. In the dehydration braking operation for stopping the washing and dewatering tub, when the rotor position detecting means detects that the washing and dehydration tub is rotating in the direction opposite to the direction in which the braking and operation is performed, the dehydration is performed. The washing machine according to claim 1, wherein the braking operation is stopped. By rotating the washing and spin-drying tub, the washing water can be sprinkled into the washing and spin-drying tub from between the outer tub and the washing and spin-drying tub. 2. The washing machine according to claim 1, wherein when the detecting means detects that the washing and dewatering tub is rotating in a direction opposite to the direction in which the washing and dewatering tub is being operated, the braking operation is stopped.

Images