JP2001079288A - Control device of washing machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce noise and to miniaturize a control device of a washing machine with an inverter circuit for driving a pump motor and to make the inverter circuit inexpensive by driving the washing motor and the pump motor with one inverter. SOLUTION: In this control device, dc power in a rectifier circuit 3 connected to an ac power source 1 is converted to ac power by an inverter circuit 4, and a washing motor 5 to drive the agitator or the washing tub is driven by the inverter circuit 4. Water is supplied to the washing tub by a water supply valve 7 and by a pump driven by a pump motor 11. The current in the inverter circuit 4 is detected by a current detecting means 6, and the inverter circuit 4 and a load switching means 12, which switches the output of the inverter circuit 4 to the washing motor 5 or the pump motor 11 are controlled by a control means 13. The inverter circuit 4 is controlled according to the output condition of the load switching means 12 and the current value detected by the current detecting means 6.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control device for a washing machine in which a pump motor is driven by an inverter circuit.

[0002]

2. Description of the Related Art In recent years, home-use washing machines have a built-in pump and supply water to the washing tub by a so-called self-priming water pump which drives the pump after injecting priming water from a water supply valve into the pump. A washing machine with a built-in pump has been proposed.

Conventionally, this type of washing machine is disclosed in Japanese Patent Application Laid-Open No. 9-28.
No. 5,687. That is,
The AC power is converted into DC power by a rectifier circuit, and the washing motor and the pump motor are each driven by two inverter circuits sharing a DC power supply.

[0004]

However, such a conventional inverter circuit for driving a pump motor is separated from the inverter circuit for driving a washing motor, so that the inverter circuit and its drive circuit, or A current detection circuit and the like are separately provided, and there is a disadvantage that the price is increased.

[0005] The present invention solves the above-mentioned conventional problems.
The pump motor is constituted by a DC brushless motor, and the washing motor and the pump motor are driven by one inverter,
The objective is to achieve low noise, small size, and low cost of the inverter circuit.

[0006]

According to the present invention, in order to achieve the above object, DC power of a rectifier circuit connected to an AC power supply is converted to AC power by an inverter circuit, and the stirring circuit or the washing tub is converted by the inverter circuit. A washing motor to be driven is driven, water is supplied to a washing tub by a water supply valve, water is supplied by a pump driven by a pump motor, current of an inverter circuit is detected by current detection means, and an inverter circuit and the inverter are controlled by control means. The load switching means for switching the output of the circuit to the washing motor or the pump motor is controlled, and the inverter circuit is controlled in accordance with the output state of the load switching means and the current value detected by the current detection means.

As a result, the inverter circuit and its control means and current detection means can be used in common, so that the apparatus for driving the pump motor can be made inexpensive, and noise and noise can be reduced by using a DC brushless motor for the pump motor. It is possible to reduce the size of the inverter circuit and its control means, thereby realizing a small and inexpensive control device for a washing machine.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS According to the first aspect of the present invention, there is provided 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, a washing motor that is driven by the inverter circuit and drives a stirring blade or a washing tub, a water supply valve that supplies water to the washing tub, and supplies water to the washing tub. A pump motor for driving a pump, current detection means for detecting the current of the inverter circuit, load switching means for switching the output of the inverter circuit to the washing motor or the pump motor, and the inverter circuit and the load switching means. Control means for controlling the inverter circuit in accordance with an output state of the load switching means and a current value detected by the current detection means. Water supply can be kept constant regardless of the frequency of the power supply.
The noise can be reduced, and the inverter circuit that drives the washing motor or the pump motor, the current detection means that detects the current of the inverter circuit, the drive circuit of the inverter circuit, or the microcomputer can be used in common. The control device of the washing machine with high cost can be realized.

According to a second aspect of the present invention, in the first aspect of the invention, the control means includes an overcurrent detection circuit for detecting an overcurrent of the inverter circuit and an overcurrent detection level setting circuit. According to the load of the motor or the pump motor, the set value of the overcurrent detection circuit is changed. Not only is the overcurrent detection circuit shared to provide a simple circuit configuration, but also according to the load state. Thus, a highly reliable control device capable of performing an optimal protection operation can be realized.

According to a third aspect of the present invention, there is provided the load according to the first aspect, wherein a rotating magnetic field is forcibly generated in the pump motor by the inverter circuit, and a current detecting means is connected to the output of the inverter circuit. An abnormality of the switching means is detected, and an abnormality of the load switching means or its driving circuit can be detected. The abnormality can be distinguished from an abnormality such as a locked state of the pump motor, and a highly reliable control device for the washing machine. Can be realized.

According to a fourth aspect of the present invention, in the first aspect, the control means includes a rotor position detecting means for detecting a position of a rotor of the pump motor, and a current detecting means of the inverter circuit. And the rotor position detecting means detects the abnormality of the pump motor. The abnormality of the pump motor can be reliably detected and distinguished from other abnormalities. The device can be realized.

According to a fifth aspect of the present invention, there is provided the load according to the third aspect of the present invention, wherein a rotating magnetic field is forcibly generated in the pump motor by the inverter circuit, and the current detecting means is connected to the output of the inverter circuit. An abnormal state of the switching means is detected, and the water absorption by the pump is stopped to supply water from the water supply valve.It is possible to detect an abnormality of the load switching means or its drive circuit. And the water supply valve supplies water to the washing tub, thereby achieving a highly reliable washing machine control device capable of continuing the washing operation.

[0013]

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

(Embodiment 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 it 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 31a is charged by the full-wave diode 30, and when the AC power supply 1 has a negative voltage, the capacitor 31b is charged and connected in series. A doubled DC voltage is generated at both ends of the capacitors 31a and 31b, and the doubled DC voltage is applied to the inverter circuit 4.

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 is generally an intelligent circuit including a power transistor and an anti-parallel diode, and a drive circuit and a protection circuit built therein. It is composed of a power module (hereinafter referred to as IPM). Inverter circuit 4
A washing motor 5 is connected to an output terminal of the rotator to drive a stirring blade or a washing tub (neither is shown).

The washing motor 5 is constituted by a DC brushless motor, and a first position detecting means 5a detects a relative position between a permanent magnet constituting a rotor and a stator. Usually the first
Is constituted by a Hall IC.
The current detecting means 6 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 7, a drain valve 8, and a clutch 9 are connected between the output AC voltage terminals of the line filter 2, and are controlled by a switching means 10. The water supply valve 7 is constituted by an electromagnetic valve for supplying tap water to the washing tub, and the drain valve 8 is constituted by a geared motor for draining the washing water in the washing tub. The clutch 9 switches the rotational drive of the stirring blade or the washing tub, and is constituted by a geared motor.

The switching means 10 comprises a bidirectional thyristor. The pump motor 11 drives a pump that absorbs bath water and supplies water to the washing tub. The pump is a self-priming pump that injects priming water from the water supply valve 7 and then absorbs water. The pump motor 11 is a three-phase DC brushless motor. It consists of.

The load switching means 12 is connected between the inverter circuit 4 and the washing motor 5, and normally drives the washing motor 5 connected to the inverter circuit 4 to rotate. The pump motor 11 is connected to the inverter circuit 4 by switching the means 12.

The control means 13 controls the washing operation by controlling the inverter circuit 4, the switching means 10, and the load switching means 12, and comprises a microcomputer 13a and its peripheral circuits. Inverter drive circuit 1
3b drives the power switching semiconductor of the inverter circuit 4, the thyristor drive circuit 13c drives the bidirectional thyristor forming the switching means 10, and the relay drive circuit 13d drives the relay forming the load switching means 12. Drive the control coil.

Here, the control means 13 includes the load switching means 1
The inverter circuit 4 is controlled according to the output state of the second circuit 2 and the current value detected by the current detecting means 6.

The second position detecting means 13e detects the back electromotive force generated in the terminal voltage of the pump motor 11, and detects the relative position between the rotor and the stator of the pump motor 11.
The current detection circuit 13f detects an inverter circuit current by detecting a terminal voltage drop of the current detection means 6 composed of a non-inductive micro-resistor. Normally, a peak value of the inverter circuit current is detected and the A of the microcomputer 13a is detected. / D conversion input terminal.

As shown in FIG. 2, the power switching semiconductor of the inverter circuit 4 is composed of a power MOSFET, and a power MOSFET connected to the + terminal of the DC power supply.
41a, 41b, 41c and high-speed diodes 42a, 42
b and 42c are called an upper arm side power device 40a,
Power MOSFET 41 connected to negative terminal of DC power supply
d, 41e, 41f and high-speed diodes 42d, 42e,
42f is called a lower arm side power device 40b.

The power MOSFET is resistant to surge current,
The feature is that a high-speed diode can be built in. Power MOS
An insulated gate bipolar transistor (IGBT for short) may be used instead of the FET. When the common ground of the control means 13 is connected to the negative terminal of the lower arm side power device 40b, the inverter drive circuit 13b can be simplified and the price can be reduced. Of course, the negative terminal of the rectifier circuit 3, that is, the capacitor 31
b may be connected to the-terminal side.

The load switching means 12 comprises a relay of two sets of contacts (2c contacts) consisting of a normally closed contact, a normally open contact, and a common terminal. To the washing motor 5 and the pump motor 1 to the normally open contact side.
1 is connected. Even if the W phase is connected in common, there is no problem in operation, and it can be constituted by one 2c contact relay, so that the number of parts can be reduced and the price can be reduced. The output signals h1, h2, h3 of the first position detecting means 5a of the washing motor 5 are:
The microcomputer 13a is connected to first position signal input terminals H1, H2, H3 of the microcomputer 13a.

The second position detecting means 13e detects the rotor position of the pump motor 11,
At the virtual neutral point (1/3 of the DC power supply voltage)
By detecting the zero crossing point from 2) and shifting the phase by 90 degrees, the same position signal waveform as the Hall IC can be obtained.

Taking the V-phase terminal as an example, a resistor 130a and a resistor 131a connected to the V-phase terminal are connected in series, a resistor 130b and a resistor 131b connected to the W-phase terminal, and a resistor connected to the U-phase terminal. A virtual neutral point is created by connecting the resistor 130c to the resistor 130c. The voltage generated at the resistor 131a from the virtual neutral point is smoothed by the capacitor 132a to shift the phase, and only the AC component is extracted by the capacitor 133a and the resistor 134a and connected to the + input terminal of the comparator 135a. The negative input terminal of the comparator 135a is connected to the virtual neutral point. A zener diode 136 is connected between the virtual neutral point and the ground to stabilize the potential.

The comparators 135a, 135b, 135
The output signal of c is applied to the second position signal input terminals φ1, φ2, φ3 of the microcomputer 13a. When the microcomputer 13a is connected to the pump motor 11 side by the load switching means 12, the microcomputer 13a operates the inverter circuit 4 according to the signals of the second position signal input terminals φ1, φ2, φ3.
Control. Second position signal input terminals φ1, φ2, φ3
Of the first position signal input terminals H1, H
2. If there is a signal change in H3, it can be determined that the load switching means 12 has failed.

The operation when the bath water is absorbed in the above configuration will be described with reference to FIG. Operation is started from step 100, and various initial settings are made in step 101.
The load switching means 12 is connected to the washing motor 5 side in the initial setting state. Step 102 is a subroutine for receiving an operation signal from an operation display means (not shown). In step 103, it is determined whether or not the bath water absorption operation is designated. If the bath water absorption operation is designated, step 1 is executed.
Go to 04.

In step 104, the current detection level of the inverter circuit 4 is set and the detection operation is started. Here, since the load of the inverter circuit 4 is set to the washing motor 5, the detected current level is set to a current level corresponding to the washing motor 5. Step 105 is a laundry amount determination subroutine for driving the washing motor 5 to determine the magnitude of the motor load.

The determination of the amount of cloth is usually made by determining the magnitude of the amount of cloth based on the motor inertia rotation speed when the washing motor 5 is driven and stopped.
If the current Im is larger than the set current Imax1, the routine proceeds to step 107, where it is determined that the cloth amount is large.

Next, the routine proceeds to step 108, where the relay 1
2 is turned on, and in step 109, the water supply valve 7 is driven for a predetermined time to execute a priming operation subroutine of the pump motor 11. In step 110, the current detection level of the inverter circuit 4 is set and the detection operation is started. Since the load of the inverter circuit 4 is set to the pump motor 11 at this time, a current value corresponding to the pump motor 11 is set.

Next, proceeding to step 111, a subroutine for driving the pump motor 11 is executed. During driving of the pump motor 11, it is determined in step 112 whether the current Ip of the inverter circuit 4 is greater than or equal to the set value Imax2. Is YES, an abnormality flag is set, and the routine proceeds to step 115, where the inverter circuit 4 is stopped to stop driving the pump motor 11, and at step 116, the relay 12 is turned off and the routine proceeds to the next step. If N is determined in step 112, the process proceeds to step 113 to detect the water level.
In step 4, it is determined whether the set water level has been reached.
Proceed to 5; if N, return to the loop of step 110.

When it is determined in step 103 that the washing operation is the normal washing operation, the normal sequence for driving the water supply valve 7 is executed without the bath water suction stroke, and the load of the inverter circuit 4 is set to the washing motor 5. Step 11
At 7, the detected current level is set to a current level corresponding to the washing motor 5. The operation after step 118 is the same as the operation of replacing the water absorption operation with the water supply valve 7, and thus the description is omitted.

Next, as another embodiment of the current control, the operation in the dehydration operation will be described with reference to FIG.

The dewatering operation is started in step 200, and various initial settings are made in step 201. The relay 12 is connected to the washing motor 5. Step 202 is a motor drive start subroutine of the spin-drying operation, in which the number of revolutions is gradually increased by a so-called soft start. In step 203 and thereafter, a current control feedback loop is performed. In step 203, the current Im of the inverter circuit 4 corresponding to the washing motor 5 is detected, and in step 204, feedback control of current and rotation speed is performed by PWM control of the inverter circuit 4.

At step 205, a current judgment is made. If the current Im of the inverter circuit 4 is larger than the current set value Ims, the routine proceeds to step 206, where the motor control speed N is set to Δ
On the other hand, if it is smaller than the current set value Ims, the routine proceeds to step 207, where the motor control rotation speed N is increased by ΔN, that is, the rotation speed control of the current minor loop is performed. There is no problem with the current feedback control of the rotation speed minor loop, but basically, control is performed so that the current and the rotation speed do not exceed the set values. At step 208, it is determined whether the dehydration is completed. If the dehydration is not completed, the feedback control is performed. If the dehydration is completed, the process proceeds to the next step.

As described above, according to the present embodiment, one inverter circuit 4 and its current detecting means 6 control the control current value according to the load of the washing motor 5 or the pump motor 11 switched by the load switching means 12. Change the inverter circuit 4 according to the load of the inverter circuit 4.
Therefore, the optimum current control according to the load can be performed with a simple circuit configuration, and a low-cost and highly reliable control device for a washing machine can be realized.

(Embodiment 2) As shown in FIG. 5, the overcurrent detection circuit 14 detects the current signal Vc of the current detection means 6 and inputs its output to the microcomputer 13a '.
When the current signal Vc exceeds a set value, the output of the inverter circuit 4 is stopped. The overcurrent detection level setting circuit 15 changes an overcurrent setting value of the overcurrent detection circuit 14.

The current signal Vc removes inverter switching noise through an RC integrating circuit including a resistor 140 and a capacitor 141, and connects the RC integrating circuit to a series connection of the resistors 142 and 143. The other terminal of the series connection is connected to the power supply voltage Vb of the signal circuit. Resistance 14
The capacitor 1 is connected between the connection point of the resistor 2 and the resistor 143 and the ground.
44 to remove noise and remove the noise-free signal vi.
To the plus input terminal of the comparator 145.

When no current flows through the current detecting means 6,
The + input terminal voltage of the comparator 145 is set to about 2 V. When a current flows, the positive input terminal voltage decreases. When the voltage drops below the-input terminal voltage of the comparator 145, the output voltage of the comparator 145 changes from high to low.

The overcurrent detection level setting circuit 15 controls the negative input terminal voltage of the comparator 145,
The setting of the overcurrent detection level can be changed. The power supply voltage Vb is divided by the resistors 150a and 150b, and the divided signal is connected to the negative input terminal voltage of the comparator 145. The collector / emitter terminal of the transistor 151 is connected to the resistor 150
The transistor 151 is turned on and off by a base resistor 152 connected in parallel with the transistor b and connected to the base terminal of the transistor 151, and the negative input terminal setting voltage vs of the comparator 145 is controlled.

When the washing motor 5 is driven to rotate, the signal S of the microcomputer 13a 'is set to high, the transistor 151 is turned on, and the set voltage vs becomes zero. Therefore, if the output signal Vc of the current detecting means 6 does not become at least -2 V or less, the comparator 128
Output is not inverted. For example, if the shunt resistor 6a of the current detecting means 6 is set to 0.2Ω, an overcurrent is detected when a current of 10 A or more flows.

When the pump motor 11 is driven to rotate, the signal S of the microcomputer 13a 'is set to low, the transistor 151 is turned off, and the set voltage v
s is set to about 1.5V. When the terminal voltage Vc of the shunt resistor 6a drops by about -0.5 V, an overcurrent detection operation is performed. That is, since an overcurrent is detected when a current of about 0.25 A flows, heat generated when the bath water pump motor 11 is locked, which is smaller than that of the washing motor 5, can be suppressed, and demagnetization of the rotor permanent magnet can be prevented. it can. In particular, since a high-speed overcurrent detection circuit can be configured, it is possible to prevent demagnetization of the rotor permanent magnet and overcurrent failure of the power transistor of the inverter circuit.

In the present embodiment, an abnormality is detected by the overcurrent detecting circuit 14 and the position detecting means, and the other configuration is the same as that of the first embodiment.

The operation when the pump motor is driven in the above configuration will be described with reference to FIG.

In step 300, the program starts,
In step 301, various initial settings are made. Step 302
To turn on the relay 12, and in step 303 the overcurrent detection level setting circuit 15 changes the current set value of the overcurrent detection circuit 14 to about 0.25 to 0.5 A, and the pump motor 1
1 does not demagnetize. Incidentally, the overcurrent detection set value when the washing motor is driven is set to 5 to 10A. Step 304 executes a subroutine that drives the water supply valve 7 to perform a priming operation on the pump motor 11.

Next, in step 305, a current is supplied to a predetermined winding of the pump motor 11 to position the rotor.
In step 306, a forced commutation subroutine for forcibly generating a rotating magnetic field in the stator is executed to drive the synchronous motor. Step 307 determines whether or not the current of the inverter circuit 4 is equal to or higher than the overcurrent detection level. If the current is equal to or higher than the overcurrent detection level, the process proceeds to step 308, where the operation of the inverter circuit 4 is stopped, the relay is determined to be abnormal, and the abnormality flag And proceed to step 309 to turn off the relay 12,
Proceeding to step 310, water supply from the water supply valve 7 is switched.

At this time, it is determined that the relay 12 is not turned on and the output of the inverter circuit 4 is connected to the washing motor 5 and that a current exceeding a set value has flowed. Judge as abnormal. Because the pump motor 11 is much smaller (about 30 W) than the washing motor (300 W or more), the stator winding impedance is high, and the synchronous motor drive does not exceed the overcurrent set value. However, the washing motor 5 has a low winding impedance, and the current value becomes larger than that of the pump motor 11 even when the forced commutation drive is performed. Since the judgment is made, the abnormality of the relay 12 can be detected.

At the end of the operation, an abnormality is notified by the abnormality flag, the content of the abnormality is stored in the non-volatile memory, and the washing operation is continued. The content of the abnormality can be displayed even after the operation by a special operation.

If overcurrent is not detected in step 307, the flow advances to step 311 to input a rotor position signal. In step 312, it is determined whether or not the synchronous motor drive time has passed a predetermined time. Step 3
Proceeding to 13, it is determined whether or not the rotational speed N of the pump motor 11 has reached a predetermined synchronous rotational speed Ns0 or more. If the predetermined synchronous rotation speed Ns0 has not been reached, the routine proceeds to step 314, where it is determined that the motor lock is abnormal, and the restart sequence of step 315 is executed just in case.

The restart sequence 315 is performed in step 30.
The sequence from the energization of the rotor positioning in step 5 to the determination of the number of revolutions in step 313 is re-executed. When the abnormality is determined again, the motor abnormality flag is set, the processing proceeds to step 309, and the relay 12 is turned off. To the water supply process.

If it is determined in step 313 that the rotational speed is normal, the process proceeds to step 316, where the second position detecting means 13e is set.
A position detection driving subroutine for generating a rotating magnetic field based on the position signal from the CPU is executed. At this time, step 317
If an overcurrent is detected in, a motor lock abnormality is determined in step 314, and a restart sequence is performed in step 315. Subsequent operations have been described above and will not be described.

If it is normal in step 317, step 31
In step 8, it is determined whether or not the position detection drive time has passed a predetermined time.
It is determined whether or not the number of revolutions N of one has reached a predetermined number of revolutions Ns1. If N, the routine proceeds to step 320, where it is determined that an overload is abnormal, an abnormality flag is set, and steps 309 and 310 are executed.

If normal in step 319, step 3
The process proceeds to step 21 to determine whether the water level in the washing tub has reached the set water level. If the water level has reached the set water level, the process proceeds to step 323 to stop driving the pump motor 11, and proceeds to step 324 to turn off the relay 12.

As described above, it is possible to distinguish the abnormality of the load switching means 12 or the pump motor 11 from the inverter current value and the motor speed according to the driving state of the pump motor 11. Can stop the water supply from the pump motor 11 and switch to the water supply from the water supply valve 7 to continue the washing operation.

[0057]

As described above, according to the first aspect of the present invention, an AC power supply, a rectifier circuit connected to the AC power supply, and an inverter for converting DC power of the rectifier circuit into AC power. A washing motor driven by the inverter circuit to drive the stirring blades or the washing tub; a water supply valve for supplying water to the washing tub; a pump motor for driving a pump for supplying water to the washing tub; and a current of the inverter circuit. Current detecting means for detecting the load switching means, a load switching means for switching the output of the inverter circuit to the washing motor or the pump motor, and a control means for controlling the inverter circuit and the load switching means. Since the inverter circuit is controlled in accordance with an output state and a current value detected by the current detection means,
The pump motor and the washing motor can be alternately driven by one inverter circuit and the current detection means, so that not only can the pump motor be reduced in size and noise, but also the inverter device can be reduced in size and cost, and reliability can be improved. A high washing machine control device can be realized.

According to the second aspect of the present invention, the control means includes an overcurrent detection circuit for detecting an overcurrent of the inverter circuit and an overcurrent detection level setting circuit, and controls the load of the washing motor or the pump motor. Since the set value of the overcurrent detection circuit is changed according to the above, a plurality of loads can be inverter-controlled by one current detection means and an overcurrent detection circuit whose setting can be changed, and the load can be changed. Even if it changes, the high-speed overcurrent detection circuit can prevent the demagnetization and heat generation of the permanent magnet of the motor, or prevent the inverter circuit from failing. A cost-effective and reliable washing machine control device can be realized.

According to the third aspect of the present invention, a rotating magnetic field is forcibly generated in the pump motor by the inverter circuit, and the abnormality of the load switching means connected to the output of the inverter circuit is detected by the current detecting means. Therefore, when the load switching means becomes abnormal, the abnormality can be detected and the protection operation and the water supply from the water supply valve can be performed, and the abnormality of the load switching means can be distinguished from other abnormalities. The work of identifying the content of the abnormality or the repair and replacement work can be shortened.

According to a fourth aspect of the present invention, the control means includes a rotor position detecting means for detecting the position of the rotor of the pump motor, the current detecting means of the inverter circuit and the rotor position detecting means. Since the abnormality of the pump motor is detected by the means, when the pump motor becomes abnormal, the abnormality is detected and the protection operation and the water supply from the water supply valve become possible, and the abnormality of the pump motor and other abnormalities are detected. Can be distinguished, and the work of identifying the content of the abnormality or the work of repair and replacement can be shortened.

According to the fifth aspect of the present invention, a rotating magnetic field is forcibly generated in the pump motor by the inverter circuit, and the abnormal state of the load switching means connected to the output of the inverter circuit is detected by the current detecting means. Detecting and stopping the water absorption by the pump to supply water from the water supply valve, so even if the load switching means fails and water absorption from the pump motor becomes impossible, water is supplied from the water supply valve to the washing tub, The washing operation can be continued.

[Brief description of the drawings]

FIG. 1 is a block circuit diagram of a control device of a washing machine according to a first embodiment of the present invention.

FIG. 2 is a main part circuit diagram of a control device of the washing machine.

FIG. 3 is a flowchart at the time of bath water suction operation of the control device of the washing machine.

FIG. 4 is a flowchart of a control device of the washing machine at the time of a dehydration operation.

FIG. 5 is a circuit diagram of an overcurrent detection circuit of a control device for a washing machine according to a second embodiment of the present invention.

FIG. 6 is a flowchart when the pump motor of the control device of the washing machine is driven.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 AC power supply 3 Rectifier circuit 4 Inverter circuit 5 Washing motor 6 Current detection means 7 Water supply valve 11 Pump motor 12 Load switching means 13 Control means

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Yutaka Inoue 1006 Kazuma Kadoma, Kadoma City, Osaka Prefecture F-term in Matsushita Electric Industrial Co., Ltd. (reference) 3B155 BA03 BA12 BB18 BB19 HB06 HB09 KA36 KB08 LC08 LC15 LC26 LC28 MA06 MA09

Claims (5)

[Claims] 1. An AC power supply, a rectifier circuit connected to the AC power supply, an inverter circuit for converting DC power of the rectifier circuit into AC power, and a washing device driven by the inverter circuit to drive a stirring blade or a washing tub. A motor, a water supply valve for supplying water to the washing tub, a pump motor for driving a pump for supplying water to the washing tub, current detection means for detecting a current of the inverter circuit, and an output of the inverter circuit for the washing motor or A load switching unit for switching to the pump motor; and a control unit for controlling the inverter circuit and the load switching unit. The inverter circuit according to an output state of the load switching unit and a current value detected by the current detection unit. A control device of a washing machine adapted to control a washing machine. 2. The control means includes an overcurrent detection circuit for detecting an overcurrent of the inverter circuit and an overcurrent detection level setting circuit, and sets the overcurrent detection circuit according to the load of the washing motor or the pump motor. The control device for a washing machine according to claim 1, wherein the value is changed. 3. The washing machine according to claim 1, wherein a rotating magnetic field is forcibly generated in the pump motor by the inverter circuit, and abnormality of the load switching means connected to the output of the inverter circuit is detected by the current detecting means. Control device. 4. The control means includes a rotor position detecting means for detecting a position of a rotor of the pump motor, and an abnormality of the pump motor is detected by a current detecting means of the inverter circuit and the rotor position detecting means. The control device for a washing machine according to claim 1, wherein 5. An inverter circuit forcibly generates a rotating magnetic field in a pump motor, a current detection unit detects an abnormal state of a load switching unit connected to an output of the inverter circuit, and stops water absorption by the pump to supply water. The control device for a washing machine according to claim 3, wherein water is supplied from a valve.