JP2003000986A - Washing machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a motor driving device for a washing machine in which a motor is driven by an inverter circuit, in which a stirring blade is rotated to reduce the amount of clothes put into the washing and dewatering tub with high accuracy. To detect. SOLUTION: DC power of a rectifier circuit 3 connected to an AC power supply 1 is converted into AC power by an inverter circuit 4, a motor 5 is driven by the inverter circuit 4, and a rotor position is detected by a rotor position detecting means 6. Control means 1
3, the inverter circuit 4 is controlled, and the motor 5 is driven by a sine wave. Based on the input current value to the inverter circuit and the amount of voltage applied to the motor at this time, the amount of clothing put into the washing and spin-drying tub is determined. Detect the amount. Further, the detection accuracy of the cloth amount is further improved by delaying the applied voltage phase from the time of the normal stirring drive.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a stirring blade for a motor,
The present invention relates to a washing machine that rotationally drives a washing / dehydrating tub.

[0002]

2. Description of the Related Art In recent years, as a household washing machine, there has been proposed a washing machine for improving dehydration performance or cleaning performance by controlling the number of rotations of a motor by an inverter device.

Conventionally, this type of washing machine is disclosed in Japanese Patent Laid-Open No. 10-1.
It was constructed as shown in Japanese Patent Publication No. 97071. That is, at the start of washing, the motor rotates the stirring blade to the left and right, and at this time, the amount of clothes put into the washing / dehydrating tub is detected by the current value flowing through the motor.

[0004]

However, in such a conventional structure, since the motor is driven by a rectangular wave, when the motor is driven, a cogging noise of the motor is generated,
Not a little noise was generated. In recent years, the amount of cloth is detected more finely, and the amount of water supply, the washing time,
It is required to realize rinsing time, dehydration time, etc., to save water, save time, etc., and the conventional configuration has a problem that it is difficult to detect a fine cloth amount.

The present invention solves the above conventional problems.
Since the rotation of the stirring blade is driven by a sine wave drive to detect the amount of clothes put in the washing / dehydrating tub, noise due to cogging noise of the motor when the stirring blade rotates can be reduced. In addition, when the motor is sinusoidally driven, by delaying the inverter circuit output voltage phase with respect to the induced voltage phase of the motor, the drive torque of the motor is weakened and the external load, that is, the clothes in the washing / dehydrating tub. The purpose of this is to make the change in the value of the current flowing through the motor more sensitive to the change in the amount of cloth, and to realize the detection of a fine cloth amount.

[0006]

In order to achieve the above object, the present invention has a stirring blade rotatably disposed in a washing / dehydrating tub, a motor for driving the stirring blade, and a switching for supplying electric power to the motor. An inverter composed of elements, a rotor position detecting means for detecting the rotor position of the motor, a rotation speed detecting means for detecting the rotation speed of the motor or the stirring blade by the output signal of the rotor position detecting means, and an input current value of the switching element. A current detecting means for detecting and a controlling means for controlling the inverter are provided, and the controlling means drives the motor with a sine wave, and the output signal from the rotational speed detecting means,
The energization ratio of the switching element of the inverter, that is, the applied voltage of the motor is controlled so that the rotational speed of the motor or the stirring blade becomes a predetermined rotational speed, and the voltage applied to the motor at this time and the switching element detected by the current detecting means. The amount of laundry put into the washing / dehydrating tub is detected from the input current value of

This makes it possible to reduce the noise such as the cogging noise of the motor generated when the stirring blade for detecting the amount of clothes put in the washing / dehydrating tank is rotated, and the fluctuation of the power supply voltage. The purpose is to accurately detect the amount of clothes put in the washing / dehydrating tub regardless of the difference in characteristics of the motor itself.

Further, the control means delays and controls the inverter output current phase with respect to the induced voltage phase of the motor as compared with the driving of the stirring blade during the normal washing operation.

As a result, the drive torque of the motor is weakened, and the change in the current value flowing through the motor becomes more sensitive to the external load, that is, the change in the amount of clothes in the washing / dehydrating tub, and the fine cloth amount The purpose is to realize the detection of.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION The invention according to claim 1 of the present invention is
A stirring blade rotatably arranged in the washing / dehydrating tub, a motor for driving the stirring blade, an inverter including a switching element for supplying electric power to the motor, a rotor position detecting means for detecting a rotor position of the motor, and a rotor. The control means includes a rotation speed detection means for detecting the rotation speed of the motor or the stirring blade based on the output signal of the position detection means, a current detection means for detecting the input current value of the switching element, and a control means for controlling the inverter. While driving the motor with a substantially sine wave, the energization ratio of the switching element of the inverter, that is, the applied voltage of the motor is controlled by the output signal from the rotation speed detection means so that the rotation speed of the motor or the stirring blade becomes a predetermined rotation speed. By controlling the voltage applied to the motor at this time and the input current value of the switching element detected by the current detection means, washing and dehydration can be performed. The amount of the entered laundry is obtained by so as to detect a, it is possible to reduce noise, such as cogging sound of a motor generated during rotation of the stirring blades, and,
It is possible to detect the amount of clothes put in the washing / dehydrating tub regardless of fluctuations in power supply voltage and differences in characteristics of the motor itself.

According to a second aspect of the present invention, in addition to the above, the control means applies the energization ratio of the switching element of the inverter, that is, the application of the motor so that the rotation speed of the motor or the stirring blade becomes a predetermined rotation speed. The voltage is controlled, the voltage applied to the motor at this time, the input current value of the switching element detected by the current detection means, the motor is stopped thereafter, and the output signal output from the rotation speed detection means after the stop The amount of laundry put into the washing / dehydrating tub is detected from these three values, and the washing / dehydrating tub can be accurately measured regardless of fluctuations in the power supply voltage and the characteristics of the motor itself. It is possible to detect the amount of clothes thrown inside.

According to the third aspect of the present invention, in addition to the above, the control means delays the inverter output current phase with respect to the induced voltage phase of the motor as compared with the drive of the stirring blade during the normal washing operation and controls the phase. Therefore, it is possible to further improve the detection performance itself of the amount of clothes put in the washing / dehydrating tub.

[0013]

Embodiments of the present invention will be described below with reference to the drawings.

(Embodiment 1) As shown in FIGS. 1, 2 and 13, an AC power supply 1 applies AC power to a rectifier circuit 3 via a line filter 2 and converts it into DC power by the rectifier circuit 3. . The rectifier circuit 3 constitutes a voltage doubler rectifier circuit. When the AC power source 1 has a positive voltage, the capacitor 3b is charged by the full-wave rectifier diode 3a, and when the AC power source 1 has a negative voltage, the capacitor 3c is charged and connected in series. A double voltage DC voltage is generated at both ends of the capacitors 3b and 3c, and the double voltage DC voltage is applied to the inverter circuit 4.

The inverter circuit 4 is composed of a three-phase full-bridge inverter circuit composed of six power switching semiconductors and an antiparallel diode, and normally, a power transistor (an IGBT can also obtain the same effect), an antiparallel diode and the antiparallel diode. Intelligent power module (hereinafter referred to as IPM) with built-in drive circuit and protection circuit
It consists of. The motor 5 is connected to the output terminal of the inverter circuit 4 to drive the rotary blade 35 or the washing / dehydrating tub 31.

The motor 5 is composed of a DC brushless motor, and the relative position (rotor position) between the permanent magnet and the stator forming the rotor is detected by the rotor position detecting means 6. The rotor position detecting means 6 is usually three Hall ICs.
(6a, 6b, 6c). The current detecting means 7, so-called shunt resistor, is connected between the negative voltage terminal of the inverter circuit 4 and the negative voltage terminal of the rectifier circuit 3.

A water supply valve 8, a drain valve 9, and a clutch 10 are connected between the output AC voltage terminals of the line filter 2 and controlled by a switching means 11. Here, the configuration of the washing machine will be described. As shown in FIG. 13, the outer tank 30
Includes a washing and dehydrating tub 31 that is rotatably disposed, and suspends a washing machine outer frame 33 with a hanging rod 32. The motor 5 includes a washing / dehydrating tub 31 and a stirring blade 35 rotatably arranged on an inner bottom portion of the washing / dehydrating tub 31 via a reduction mechanism.
To rotate. The water supply valve 8 is for washing and dehydrating the tap water 31
The drainage valve 9 controls drainage of water in the washing / dehydrating tub 31. Clutch 10
Controls whether the rotational drive shaft of the motor 5 is connected to the stirring blade 35 or the washing / dehydrating tub 31. The switching means 11 is composed of a solid state relay such as a bidirectional thyristor or a mechanical relay.

The control circuit 12 controls the inverter circuit 4 and the switching means 11, and includes a control means 13 composed of a microcomputer and a control means 13.
An inverter drive circuit 14 that controls the IPM of the inverter circuit 4 by the output signal of
A switching means drive circuit 15 for controlling the switching means 11 and a current detection circuit 16 for detecting the current of the inverter circuit 4 by the output signal of the current detection means 7 and applying a signal according to the motor current to the control means 13. is doing.

Further, the control circuit 12 controls the switching means 11 to control the operations of the water supply valve 8, the drain valve 9, the clutch 10, etc., and controls a series of steps of washing, rinsing and dehydrating.

In the washing process, the stirring blades 35 are rotated to the left and right, and mechanical force is applied to the cloth to remove stains on the clothes.
In the dehydration process, the washing / dehydrating tub 31 is rotated and the washing water used for washing is squeezed from the clothes.

The control means 13 controls the overall operation of the washing machine such as controlling the washing operation in time series (details omitted), and also controls the IPM of the inverter circuit 4 to drive the motor 5. The control means 13 has a carrier signal generation circuit and a comparison circuit, and has a PWM control means 18d that controls the IPM of the inverter circuit 4, a waveform storage means 18e that outputs the output voltage of the inverter circuit 4 to a desired waveform, and a rotor. Electrical angle control means 18b for calculating an electrical angle from the output signal of the position detection means 6 and the output signal of the carrier signal generation circuit.
An output level conversion circuit 18c for calling the signal of the waveform storage means 18e by the electrical angle control means 18b and outputting the signal to the PWM control means 18d in synchronization with the output signal of the carrier signal generation circuit, and the signal of the rotor position detection means 6a. The rotation speed control means 18a for controlling the rotation speed by changing the output signal level of the electrical angle control means 18b according to the error signal obtained by comparing the detected rotation speed with the set rotation speed, and the voltage for controlling the motor applied voltage phase. It is constituted by the phase setting means 18f.

The control means 13 is constructed as shown in FIG. 2, and the PWM control means 18d causes the carrier signal generation circuit 181d to generate a sawtooth wave and the comparison circuit 1
The signal vc is applied to the input terminal of 82d, and the comparison circuit 182d
The signal vu from the voltage setting means 180d is applied to the other input terminal of the carrier wave generator 181d, and the cycle of the carrier signal generation circuit 181d becomes 64 μs when the carrier frequency is set to 15.6 kHz, and the signal level changes in proportion to time. Generate. The sawtooth wave has a higher PWM resolution and is superior to the triangular wave. Further, in the case of a sawtooth wave, there is a drawback that the N-th harmonic of the carrier frequency increases as compared with the triangular wave. However, if the carrier frequency is set to the ultrasonic frequency, the N-th harmonic of the carrier frequency will not cause noise. This problem disappears as the impact disappears.

The comparison circuit 182d is a digital comparator in the microcomputer and compares the data of the voltage setting means 180d composed of a double buffer with the carrier signal of the sawtooth wave to generate a PWM waveform. The PWM control means 18d shown in FIG. 2 is for one phase of three outputs and has three similar circuits in the case of three phase output. However, one carrier signal generation circuit 181d can be shared.

The waveform storage means 18e stores a desired voltage signal (sine wave data) corresponding to an electrical angle.
It is an array of 56 (8 bits) to 512 (9 bits) numerical data. Numerical data corresponding to voltage amplitude is 9-bit data, and normally stores sine wave data corresponding to electrical angle from -256 to +256. Since this numerical data is so-called normalized data and the way of holding the data is not particularly specified, it is desirable to use a numerical array that makes the program execution speed as fast as possible.

The electrical angle detecting means 18b detects the output signal of the rotor position detecting means 6 and detects the rotation cycle, and the rotation cycle detecting means 182b and the reference rotor position detecting means 6b.
Phase setting means 181b for setting the phase angle φb from the output signal H1 of the carrier signal generating circuit 181d and the carrier signal generating circuit 181d for counting the number of output pulses k within a period corresponding to the electrical angle of 60 degrees detected by the rotation cycle detecting means 182b. Signal 1
An electrical angle calculation means 183b for calculating the electrical angle Δθ of the cycle and an electrical angle corresponding to the rotor position, and a rotor electrical angle and phase setting means 18 calculated by the electrical angle calculation means 183b.
Electrical angle setting means 18 for setting the applied voltage electrical angle from 1b
It is composed of 0b.

The output level conversion circuit 18b calls the amplitude signal A corresponding to the electrical angle from the waveform storage means 18e, and the PWM control means 18d by calculating the modulation degree G on the output signal A of the calling means 180c. It is composed of a voltage calculation means 181c for outputting. Normally, the data in the waveform storage means 18e is a numerical value corresponding to the maximum output level of the inverter circuit 4, so the voltage calculation means 181 is used.
The calculation of c is a calculation for reducing the inverter output voltage level, and the modulation degree G is a numerical value smaller than 1. Usually, the modulation factor in sine wave PWM is called percentage (%).

The modulation degree G is output by the rotation speed control means 18a, and the rotation speed control means 18a determines the rotation speed from the signals of the rotation speed setting means 181a for setting the motor rotation speed to a predetermined value and the rotor position detecting means 6a. The rotation speed detecting means 180a for detecting and the rotation speed comparing means 182a for comparing the detected rotation speed with the set rotation speed and outputting an error signal control the modulation degree G.

The voltage phase setting means 18f sets and controls the phase of the inverter circuit output voltage according to the condition for driving the motor 5. Since the phase of the inverter circuit output voltage and the motor current phase do not always become the same phase, each drive condition of the motor 5 is previously set (rotating the stirring blade, washing operation, dehydration operation of rotating the washing / dehydrating tank 31 and the like). Then, the inverter circuit output voltage phase and the motor current phase at that time are experimentally observed, and the inverter circuit output voltage phase is set based on the test data. The set phase has higher efficiency as the motor induced voltage Ec and the phase of the motor current are closer to each other. Therefore, the inverter circuit output voltage phase that satisfies this condition is optimal. Further, there is a control method for setting the inverter circuit output voltage phase in a so-called field-weakening state in which the motor current phase advances with respect to the motor induced voltage Ec when the torque is emphasized.

In the above-mentioned structure, the waveform relationship of each part corresponding to the electrical angle is as shown in FIGS. 3 and 4.

FIG. 3 shows the relationship between the waveforms of various parts when the motor is driven to rotate during the normal washing operation. In FIG. 3, Ec is the motor induced voltage waveform, which is the rotor position signal H1, H2 of the rotor position detecting means 6, The signal of H3 changes at every 60 electrical angle, and the motor induced voltage Ec has a phase delayed by 30 electrical angle when the timing at which the reference signal H1 changes from Lo to Hi is 0 degree. The state data of the rotor position signals H1, H2, H3 are read in synchronization with changes in the rotor position signals H1, H2, H3, and the rotor electrical angle can be detected every 60 degrees from the state data.

The signal vc is a carrier signal generation circuit 181d.
It is the output signal of the sawtooth wave and is the timer value of the timer counter that changes from 0 to 512. When the timer value reaches 512, the timer counter overflows and returns to 0,
The carrier interrupt signal c is generated.

The signal vu is one input signal of the comparison circuit 182d and is basically the same as the output signal of the output level conversion circuit 18c. In this case, the phase angle φ is 0 degree and the modulation degree G is 100 degrees. The case of% is shown. This signal vu is the amplitude signal A (-2 of the sine wave data stored in the waveform storage means 18e.
56 to +256) is multiplied by the modulation degree G and 256 is added, and is calculated from vu = A × G + 256. It changes from 0 to 512 in a sine wave shape with 256 as the center value.

The signal u shows a PWM waveform in which the signal vu and the output data vc of the carrier signal generation circuit 181d are compared in magnitude. The signal u drives the inverter circuit 4 via the inverter drive circuit 14, and by applying a voltage to the motor 5, it is possible to drive the motor 5 with a substantially sinusoidal current, resulting in noise generated from the motor 5. Vibration can be reduced.

The signal u is a drive signal for the U-phase upper arm transistor, and the drive signal for the lower arm transistor is an inverted signal of the signal u. The signal actually applied to the transistor is further subjected to dead time control in consideration of the turn-off time, and a period for prohibiting simultaneous conduction of the upper and lower arm transistors is provided.

As a result, the rotor position electrical angle is detected by calculation in synchronization with the carrier signal, and the waveform storage means 18e is used.
Since the sine wave data stored in can be read out,
The frequency of the carrier signal can be increased to improve the rotor position detection and decomposition performance, the rotation speed control performance of the motor 5 can be improved, and the motor noise can be reduced.

FIG. 4 shows the time when the motor current phase is delayed by the output voltage phase of the inverter circuit with respect to the induced voltage waveform (later described, when the stirring blade is rotated when the amount of cloth in the washing / dehydrating tub is detected). 3 shows the relationship between the waveforms of each part. Inverter output voltage phase is the phase angle φ (0 degree) during normal motor drive
On the other hand, it is a waveform when delayed by about 10 degrees. Since the U-phase current Iu is delayed due to the winding inductance of the motor 5, the U-phase current Iu is actually delayed by about 40 degrees with respect to the reference phase H1.
The waveform is delayed by about 10 degrees with respect to the induced voltage waveform Ec.

In this way, for example, by driving the motor with the U-phase current Iu waveform delayed by about 10 degrees with respect to the induced voltage waveform Ec, the torque of the motor 5 decreases.
The change in the motor phase current Iu becomes large with respect to the difference in the external load.

Next, an embodiment will be described with reference to the flowchart of FIG. First, the laundry is put in the washing / dehydrating tub 31, and then in step 200, the washing operation is started. In step 201, the motor 5 is turned on. This time,
The stirring blade 35 has a set rotation speed of N1 (120 r / min), and the rotation speed control means 18a controls the modulation degree G.
The control is performed so that the set rotation speed becomes N1. Step 202
Then, the start control of the motor 5 is performed. When starting the motor 5,
The rectangular wave drive is set, the motor 5 is started by a predetermined PWM setting value, and the rotor is rotated from 1/4 to 1 rotation before switching to the sine wave drive. The rectangular wave drive is also called 120-degree energization control, and is the simplest control method of DC brushless forming the motor 5 and capable of obtaining a large starting torque.
3 which constitutes the inverter circuit 4 by the rotor position signal
The motor current can be controlled by performing PWM control on only one side of the upper arm transistor or the lower arm transistor of the phase full bridge inverter.

In step 203, the sine wave PWM control as described above is switched. In the sine wave PWM control, the upper arm transistor and the lower arm transistor are alternately turned on and off. For example, an inverted signal of the drive signal u of the U-phase upper arm transistor becomes the drive signal of the U-phase lower arm transistor, and The transistor is PWM controlled at the carrier signal frequency. Step 20
After proceeding to 4, the rotation speed control subroutine is executed. The rotation speed control mode (rotation speed control subroutine)
The voltage phase setting means 18f sets the inverter output voltage phase φ so that the motor current lags behind the induced voltage phase (for example, 10 degrees). This inverter output voltage phase φ
Under this setting, the modulation degree G is controlled, and feedback control is performed so that the rotation speed of the stirring blade 35 converges to the set rotation speed N1. As a feedback control method, as described above, the rotation speed detection means 181a detects the current rotation speed of the stirring blade 35 from the signal from the rotor position detection means 6a,
The modulation degree G is controlled by the rotation speed comparison means 182a which compares the detected rotation speed with the set rotation speed N1 and outputs an error signal. In this feedback control, in step 204, it is detected whether the signal from the rotor position detecting means 6a has changed, and if there is a signal change, it is determined that there is a pulse input, and the flow proceeds to step 205. In step 205, the pulse input CT for counting and storing the number of pulse inputs is counted, and in step 206, the stirring blade 3 is changed by the change cycle of the signal from the rotor position detecting means 6a.
The current rotation speed of 5 is detected. In step 207, the modulation degree G is controlled based on the difference between the current rotation speed of the stirring blade 35 and the set rotation speed. Then, in step 209, the input current of the inverter circuit 4 is detected by the output signal from the current detection circuit 16. In step 209, it is determined whether a predetermined time t1 for rotating the stirring blade 35 has elapsed, and the time t1
The feedback control from step 104 onward is performed until is passed. When the time t1 has elapsed, the rotating operation of the stirring blade 35 is terminated, and the process proceeds to step 210 to stop the operation of the motor 5.

The operation from step 201 to step 210 is performed twice alternately in the rotating direction of the stirring blade 35 and right and left, and then the process proceeds to step 211 to detect the amount of cloth. In step 211, the value n of the pulse input CT, which counts the number of times the signal from the rotor position detecting means 6a changes during the feedback control, and n, which is stored each time the pulse input CT is counted. Input current value (I1, I2, I3, ... In) to the inverter circuit 4 and the modulation degree G (G1, G2, G3 ,. From
The average current value Iavg and the average modulation degree Gavg are calculated. Then, a function Z = Iavg−K · Gavg (K is a constant) of the average current value Iavg and the average modulation degree Gavg is calculated, and this Z is calculated.
The amount of cloth is detected by the value.

FIG. 6B shows the relationship between the input current value to the inverter circuit 4 and the cloth amount according to the inverter output voltage phase φ. As the amount of cloth increases, the force applied to the stirring blade 35 increases and the torque of the motor 5 increases, so the input current value to the inverter circuit 4 also increases. Further, when the inverter output voltage phase φ is changed within a certain range (setting is made so that the current phase is delayed by about 0 to 10 degrees with respect to the induced voltage), the input current value to the inverter circuit 4 remains unchanged even with the same cloth amount. Change. As a tendency at this time, when the current phase is controlled to be delayed with respect to the induced voltage, the input current value becomes large even with the same amount of clothes.

Next, the relationship between the modulation degree G and the cloth amount is shown in FIG.
It shows in (b). The larger the amount of cloth, the more the torque increases, and the more current needs to flow, the larger the modulation degree G becomes. The modulation degree also changes depending on the magnitude of the power supply voltage. With the same amount of cloth, a lower power supply voltage requires a larger amount of current to flow, so that the degree of modulation G increases. That is, the modulation degree G
The influence of the power supply voltage can be reduced by detecting the amount of cloth from the values of 2 and the current value.

7 (a) and 7 (b) show the relationship between the current value, the degree of modulation, and the cloth amount. Further, FIG. 7A shows a case where the inverter output voltage phase φ is set so that the current phase is substantially the same as the induced voltage phase.
In (b), the inverter output voltage phase φ is set so that the current phase is delayed by about 10 degrees with respect to the induced voltage phase. Thus, not only the current value but also the modulation degree G
By using, it is possible to detect the cloth amount without being affected by the power supply voltage, and by delaying the current phase with respect to the induced voltage phase, it is possible to detect the cloth amount more accurately.

On the other hand, a detailed flowchart of the sine wave drive will be described with reference to FIG. In step 300, start-up control of the motor 5 is performed, and the process proceeds to step 301. Since steps 302 to 304 overlap the above-mentioned contents, step 304 will be described. In step 304, it is determined whether or not there is a carrier signal interrupt c. When the carrier signal interrupt c occurs, the process proceeds to step 305 and the carrier signal interrupt subroutine is executed.

The details of the carrier signal interruption subroutine will be described with reference to FIG. 9. Briefly speaking, the rotor position electrical angle is detected by counting carrier signals, and the sine wave is stored in the waveform storage means 18e according to the electrical angle. The wave data is called and the PWM control data is set. The execution and return of this subroutine must be processed within a few μsec to a few tens of μsec.

Next, in step 306, drive control of the IGBT constituting the inverter circuit 4 is performed. PWM
The output setting means 182d of the control means 18d has a double buffer structure, and the signal actually output after the PWM value is changed becomes the timing of the next carrier signal.

Step 307 is to detect a change in the rotor position signal. The edge signals of the rotor position signals H1, H2 and H3 are detected to detect whether or not an interrupt signal is generated. Proceeding to 308, the position signal interruption subroutine is executed. The priority of the position signal interrupt is set after the carrier signal interrupt.

The details of the position signal interrupt subroutine will be described with reference to FIG. 10. Briefly,
Rotor rotation cycle and rotation speed detection, 0 degree, 60 degree, 120
The electric angle is set every 60 degrees such as degrees, and the electric angle of one cycle of the carrier signal is calculated.

This position signal interrupt subroutine 210
However, high-speed processing is required as in the carrier signal interrupt subroutine, and it is necessary to perform processing within several μsec to ten and several μsec. Because, even if two interrupts are overlapped at the same time, one carrier signal cycle (64 μs) is 50
If it is not processed within%, the main routine cannot be executed, which may hinder the execution of the program.

In step 309, it is determined whether or not the driving operation of the motor 5 is finished. If it is continued, the process returns to step 204, and if it is finished, the process proceeds to step 310 to turn off all the IGBTs and then stop the carrier signal counting. , End a series of sine wave drive control.

Next, the position signal interrupting operation when the output signal of the rotor position detecting means 6, that is, the edge of the rotor position signals H1, H2, H3 is detected will be described with reference to FIG.

From step 400, an external interrupt is generated by the edge signal and the position signal interrupt subroutine is started. In step 401, the rotor position signals H1, H2, H3 are generated.
Input the status data of to detect the rotor position. In step 402, the rotor electrical angle θc is set from the rotor position signal. If the U phase has an electrical angle of 0 degrees, the V phase has 120 degrees,
The W phase is set to 240 degrees.

Next, proceeding to step 403, the count value k of the pulse number of the carrier interrupt signal c of the carrier signal generating circuit 181d is stored in the carrier counter memory kc, and proceeding to step 404, the count value k is cleared to step 405, the carrier signal generation circuit 181
The electrical angle Δθ of one cycle of the output signal of d is calculated. Since the position signal interrupt cycle corresponds to an electrical angle of 60 degrees, Δθ = 6
It is represented by 0 / kc. If 360 degrees has a resolution of 8 bits (256), it is expressed as Δθ = 42 / kc.

By calculating the electrical angle per cycle of the carrier signal generating circuit 181d, the electrical angle can be calculated and detected even if the rotation cycle changes, and the rotor position detection accuracy can be improved. A desired voltage waveform according to the electrical angle of the rotor can be applied to the motor 5.

Since the frequency of the carrier signal is set to the ultrasonic frequency of 15 kHz or more, the count value kc can ensure a resolution of at least 10 or more even in the motor rotation speed during the dehydration operation, and a resolution of 60 or more at one electrical angle. Can be secured. If there is a margin in the instruction execution speed of the microcomputer, when the carrier frequency is set to 15.6 kHz and the 8-pole motor is driven at 900 r / min, the resolution of 245 can be secured and the voltage waveform is almost a sine wave even in the dehydration rotation. Can be driven by.

Next, the routine proceeds to step 406, where it is judged if the reference electric angle is 0 degree, that is, if the rotor position signal H1 changes from L to H, and if Y, step 40
In step 7, the measured value of the cycle measuring timer counter T is stored in the cycle measuring memory To, and in step 408, the timer counter T is cleared. After that, the routine proceeds to step 409, where the rotor speed N is obtained from the cycle To.

The timer counter for period measurement raises the clock frequency to 1 to 10 μs in order to improve the measurement accuracy, and counts the signal obtained by dividing the reference clock of the microcomputer by the hard timer.

Next, in step 411, the rotation speed control mode is set, and the modulation degree G is controlled by the error signal between the set rotation speed Ns and the detected rotation speed N. The phase φ at this time is set with respect to the reference value (according to the driving condition in the range of 0 to 30 degrees) as described above. During normal stirring operation, if priority is given to efficiency, a retard angle of 10 degrees to a retard angle of 20 degrees is optimal.

After controlling the modulation degree G, the routine proceeds to step 412, where the counting of the timer counter for measuring the period To is started.

Next, the carrier signal interrupt operation will be described with reference to FIG. FIG. 9 is a flowchart of the carrier signal interrupt subroutine, in which the electrical angle corresponding to the rotor position is calculated in synchronization with the carrier signal,
The signal of the waveform storage means 18e is read and PWM output is performed. When the timer counter of the carrier signal generation circuit 181d overflows, an interrupt signal is generated,
The carrier signal interrupt subroutine starting at step 500 is executed.

In step 501, the count value k of the carrier counter is incremented, and then in step 402.
Then, the inverter circuit output electrical angle θ is calculated.

The electrical angle θ is obtained by multiplying the product of the electrical angle Δθ of one cycle of the carrier signal and the count value k of the carrier counter by the sum of the phase φ and the electrical angle θc detected by the position signal interruption subroutine. The calculated value of Δθ × k + θc means the rotor position electrical angle, and the phase φ shows the voltage phase applied to the motor 5. The electrical angle θ is calculated for each of the U, V, and W phases.

Next, in step 503, the waveform data corresponding to the electrical angle θ is retrieved from the waveform storage means 18e. If it is sine wave data, the called data is sin θ
Becomes However, the amplitude data is a value of -256 to +256. Since the maximum value of the electrical angle is 360 degrees, when θ becomes 360 degrees or more, it returns to 0 and the data is read. Next, in step 504, the signal vu is calculated from the modulation degree G obtained in the position signal interruption subroutine, and in step 505
Then, the data is transferred to the output setting buffer of the comparison circuit 182d which applies a signal to the PWM control means 18d, that is, the second PWM control means 18d, and the routine returns to step 506 to return to the subroutine. Step 5 for V phase and W phase
From 02 to step 505, the same processing as in the U phase is performed.

The processing within the carrier signal interrupt subroutine must be completed within one cycle of the carrier signal.
If the carrier frequency is 15.6 kHz, the latest is 30μ
It is necessary to finish the process within s, and if the process is a program step where the process does not finish within 30 μs, the program is divided, and the carrier interrupt is divided into the U phase at the first time, the V phase at the second time, and the W phase at the third time. You may make it process.

(Second Embodiment) The configuration is the same as that of the first embodiment. The operation of the above configuration will be described with reference to the flowchart of FIG. The washing operation is started in step 600, the motor 5 is turned on in step 601, and the stirring blade 35 is operated. At this time, the set rotation speed of the stirring blade 35 is set to N1 (120 r / min), and the rotation speed control means 18
The degree of modulation G is controlled by a so that the set rotational speed becomes N1. After starting the motor 5 in step 602, the process proceeds to step 603, and the above feedback control is performed. At step 604, the drive is shifted to the sine wave drive, and thereafter feedback control is performed. Since steps 605 to 610 are the same as the flowchart described in the first embodiment, the description thereof will be omitted. In step 610, it is determined whether the time t1 has elapsed. When the time t1 has elapsed, the feed bag control is stopped in step 611, the motor 5 is turned off, the process proceeds to step 612, and the rotor 5 is turned off many times. Only the change in the signal from the position detecting means 6 is counted in step 614 until the time t2 elapses.

The operations from step 602 to step 614 are performed twice alternately in the left and right directions of rotation of the stirring blade 35, and then the process proceeds to step 615 to detect the amount of cloth.

FIG. 11 shows the relationship between the number of pulses when the motor is off and the cloth amount (a normal distribution is used in the correlation diagram showing the frequency that can be the cloth amount with respect to the number of pulses). The larger the amount of cloth, the larger the friction coefficient between the stirring blade 35 and the cloth, the shorter the time from turning off the motor 5 until the stirring blade 35 stops, and the change in the signal from the rotor position detecting means 6. The number of pulses (the number of pulses) is also reduced.

Therefore, as in the first embodiment, the function Z = Iavg-K.multidot.of the average input current value Iavg and the average modulation degree Gavg.
The value of Gavg (K is a constant) and when the motor 5 is off,
By detecting the cloth amount based on the number of signal changes from the rotor position detecting means 6, the cloth amount detection accuracy can be further improved. Table 1 shows an example of a cloth amount detection method.

[0069]

[Table 1]

When the amount of cloth is large from about 3 kg to 6 kg or more, since the average input current value Iavg and the function Z of the average modulation degree Gavg are large, the cloth amount is directly determined from the value of Z and Z
When the value of is small, it is determined to be about 3 kg or less, and the cloth amount is finely determined by the number of pulses.

In this embodiment, the average input current value Iav
The cloth amount is once determined by g and the function Z of the average modulation degree Gavg, and a part of the determination result is again determined by the number of pulses when the motor 5 is off. The calculation method and combination of are not limited to this.

[0072]

As described below, according to the invention described in claim 1 of the present invention, the stirring blade rotatably arranged in the washing / dehydrating tub, the motor for driving the stirring blade, and the electric power to the motor are supplied. An inverter composed of a switching element to be supplied, a rotor position detecting means for detecting the rotor position of the motor, a rotational speed detecting means for detecting the rotational speed of the motor or the stirring blade by an output signal of the rotor position detecting means, and an input of the switching element. A current detection unit that detects a current value and a control unit that controls the inverter are provided, and the control unit drives the motor by a sine wave, and the rotation speed of the motor or the stirring blade is determined by the output signal from the rotation speed detection unit. The energization ratio of the switching element of the inverter, that is, the applied voltage of the motor is controlled so that the predetermined rotation speed is achieved, and the voltage applied to the motor at this time and the current detection means It is designed to detect the amount of laundry put into the washing and dehydrating tub from the value of 2 and the detected input current value of the switching element. It is possible to reduce the noise such as the above, and it is possible to detect the amount of clothes put in the washing / dehydrating tub regardless of the fluctuation of the power supply voltage and the difference of the characteristics of the motor itself.

According to the second aspect of the invention, the control means controls the energization ratio of the switching element of the inverter, that is, the applied voltage of the motor so that the rotation speed of the motor or the stirring blade becomes a predetermined rotation speed. , The voltage applied to the motor at this time, the input current value of the switching element detected by the current detection means, and the output signal output from the rotation speed detection means after the motor is stopped after the stop. The value is used to detect the amount of laundry put into the washing / dehydrating tub, and is accurately put into the washing / dehydrating tub regardless of fluctuations in the power supply voltage and differences in the characteristics of the motor itself. It is possible to detect the amount of worn clothes.

According to the third aspect of the present invention, the control means controls the inverter output current phase with respect to the induced voltage phase of the motor by delaying the phase of the stirring blade during the normal washing operation. Therefore, it is possible to further improve the performance of detecting the amount of clothes put in the washing / dehydrating tank.

[Brief description of drawings]

FIG. 1 is a block circuit diagram of a first embodiment of the present invention.

FIG. 2 is a block diagram of the washing machine.

FIG. 3 is a time chart of a motor drive device of the washing machine.

FIG. 4 is an operation timing chart when controlling the inverter of the washing machine.

FIG. 5 is an operation flowchart when the washing machine is controlled by an inverter.

FIG. 6 (a) Correlation characteristic diagram between the inverter input current and the laundry amount of the washing machine (b) Correlation characteristic diagram between the modulation degree and the laundry amount of the washing machine

FIG. 7 (a) Correlation characteristic diagram of the input current value of the washing machine, the degree of modulation, and the amount of cloth. (B) When the input current value of the washing machine, the degree of modulation, and the phase amount of the amount of cloth are delayed. Correlation diagram

FIG. 8 is an operation flowchart of main parts of the washing machine.

FIG. 9 is an operation flowchart of main parts of the washing machine.

FIG. 10 is an operation flowchart of main parts of the washing machine.

FIG. 11 is a main part operation flowchart of the second embodiment of the present invention.

FIG. 12 is a correlation characteristic diagram showing the number of pulses of the washing machine and the frequency with respect to the amount of cloth.

FIG. 13 is a sectional view of the washing machine

[Explanation of symbols]

1 AC power supply 3 rectifier circuit 4 Inverter circuit 5 motor 6 Rotor position detection means 13 Control means 16 Current detection circuit 35 Stirrer

   ─────────────────────────────────────────────────── ─── Continued front page    F term (reference) 3B155 AA01 BB19 CA06 CB06 KA02                       KA34 KB08 KB11 LA11 LC12                       LC15 MA01 MA06 MA07 MA08                       MA09

Claims (3)

[Claims] 1. An agitator, which is rotatably disposed in a washing / dehydrating tub, a motor for driving the agitator, and an inverter including a switching element for supplying electric power to the motor.
Rotor position detection means for detecting the rotor position of the motor, rotation speed detection means for detecting the rotation speed of the motor or the stirring blade based on the output signal of the rotor position detection means, and input current value of the switching element Current detecting means for controlling, and control means for controlling the inverter, the control means, while driving the motor with a substantially sine wave, by the output signal from the rotation speed detection means,
The conduction ratio of the switching element of the inverter so that the rotation speed of the motor or the stirring blade becomes a predetermined rotation speed,
That is, the applied voltage of the motor is controlled, and the amount of the laundry put into the washing / dehydrating tub is detected based on the applied voltage to the motor and the input current value of the switching element detected by the current detecting means. Washing machine to do. 2. The control means controls the energization ratio of the switching element of the inverter, that is, the applied voltage of the motor so that the rotation speed of the motor or the stirring blade becomes a predetermined rotation speed, and the application to the motor at this time. Voltage, the input current value of the switching element detected by the current detection means,
The motor is stopped after that, and the amount of the laundry put into the washing / dehydrating tub is detected from three values of the output signal output from the rotation speed detecting means after the stop. Washing machine. 3. The washing machine according to claim 1, wherein the control means delays and controls the inverter output current phase with respect to the induced voltage phase of the motor as compared with the driving of the stirring blade during the normal washing operation. .