JPH05285292A - Washing machine - Google Patents

Abstract

PURPOSE:To suppress the temperature rise of a driving motor by continuous application of high voltage by monitoring the rotating state of the driving motor in a washing machine, controlling a converting means for changing the magnitude of the driving voltage to the driving motor so that the driving motor is rotated at a standard rotating speed. CONSTITUTION:A three-phase dielectric motor 6 drives the drum of a washing machine, whereby the drum is reversed at low speed at the time of washing or drying, while it is rotated in one direction at high speed at the time of spin- drying. A reed switch 11 monitors the rotating driving state of the motor 6 through the drum. Further, an IGBT module 15 changes and converts the magnitude of driving voltage in the motor 6. A first microcomputer 14 controls the operation of the IGBT module 15 so that the motor 6 is rotated at a standard rotating speed on the basis of the monitor information from the reed switch 11. Thus, the magnitude of the driving voltage is properly controlled to solve the regular application of high voltage to the motor 6, whereby the temperature rise of the motor 6 is suppressed to prevent the burning.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a washing machine.

[0002]

2. Description of the Related Art Conventionally, there is a washing machine which performs steps such as washing, rinsing, and dehydration by rotating a dehydration / washing tub itself or a rotary wing arranged in the washing tub by a drive motor. For example, Japanese Patent Laid-Open No. 1-218494 (D
06F33 / 02).

In such a washing machine, the magnitude of the power supply voltage is not always constant and may vary depending on the region or time zone. For example, AC100V is AC9.
It may be 0V. Also, as the performance of the washing machine,
Even if the amount of laundry in the washing tub is the rated full amount (for example, 4 Kg in the case of a washing machine of 4 Kg washing), it is necessary to start without any trouble and rotate at a predetermined rotation speed.

Therefore, in such a washing machine, the driving voltage is increased in advance in consideration of the above situation, that is, the decrease in the power supply voltage.

[0005]

In the conventional washing machine, since a high drive voltage is constantly applied to the drive motor, for example, when the ambient temperature is high, the temperature of the drive motor during operation is There has been a problem that the temperature exceeds the temperature at which the normal operation is guaranteed (operation guarantee temperature), and as a result, the motor is damaged or ignites.

The present invention relates to improvement of a washing machine and solves such a problem.

[0007]

SUMMARY OF THE INVENTION According to the present invention, the steps of washing, rinsing, dehydrating, etc. are performed by rotating a dehydration-cum-washing tub itself or a rotary blade disposed in the washing tub with a drive motor. A washing machine for performing, wherein the monitoring means for monitoring the rotation state of the drive motor, the conversion means for changing the magnitude of the drive voltage of the drive motor, and the drive motor based on the information from the monitoring means. And a control means for controlling the operation of the conversion means so as to rotate at a reference rotation speed.

Further, the present invention is a washing machine for carrying out steps such as washing, rinsing, and dehydrating by rotating a dehydrating / washing tub itself or a rotary blade disposed in the washing tub by a drive motor. There is a control means for controlling the drive motor so as to rotate forward and reverse with a pause during the washing and rinsing steps, and a temperature detection means for detecting the temperature of the drive motor.
The control means comprises: storage means for storing a predetermined temperature lower than an upper limit temperature at which normal operation of the drive motor can be guaranteed; and comparison means for comparing the temperature detected by the temperature detection means with the predetermined temperature. When the temperature detected by the temperature detecting means exceeds the predetermined temperature, the ratio of the rest time in one cycle of the rest-rotation time of the drive motor is increased.

[0009]

First, the converting means outputs the initial voltage to start the drive motor. After that, the control means changes the magnitude of the drive voltage by the conversion means so that the drive motor rotates at the reference rotation speed based on the information from the monitoring means.

That is, the drive motor has a certain amount of laundry,
In addition, when the power supply voltage has a certain magnitude, the motor rotates steadily at a predetermined rotation speed. On the other hand, when the power supply voltage is constant and the amount of laundry increases and the load on the drive motor increases, the drive motor rotates at a rotational speed slightly lower than the predetermined rotational speed. When the load decreases and the load decreases,
It rotates at a slightly higher speed. Also, if the load is constant,
Since the torque increases as the power supply voltage increases, the drive motor rotates at a speed slightly higher than the predetermined rotation speed, and the torque decreases as the power supply voltage decreases, so the drive motor rotates at a slightly lower speed.

For this reason, in the present invention, first, the reference rotational speed of the drive motor is determined so that the effect can be sufficiently exerted in each step such as washing and rinsing. Then, data relating to the rotation speed of the drive motor, such as the drive motor itself, the spin-drying / washing tub, and the rotation speed of the rotating blades disposed in the washing tub, is monitored in advance, and this rotation speed can The drive voltage of the motor, that is, the magnitude of torque is changed so that the reference rotation speed is always maintained even if the power supply voltage changes.

Therefore, the drive voltage is adjusted so that the drive voltage is lowered when the load becomes small and the drive voltage does not become high when the power supply voltage becomes high, so that a high voltage is constantly applied to the drive motor. It is not applied.

Further, in the washing and rinsing step, the drive motor makes one cycle of forward and reverse rotation for a predetermined time with a pause, and repeats this operation. At this time, if the temperature of the drive motor rises and exceeds a predetermined temperature due to, for example, continuing to apply a high voltage in a state where the ambient temperature is high, the control means causes the drive motor to operate for one cycle. In, increase the percentage of rest time.

[0014]

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

2 and 3, 1 is a machine frame, 2 is an outer tank elastically supported in the machine frame 1, and 3 is this outer tank 2.
It is a horizontal shaft type drum rotatably supported inside and has a large number of through holes 4 ... 5 is an upper lid that opens and closes a clothes inlet provided at the top of the machine frame 1, 6 is the drum 3
Is a three-phase induction motor that reverses at low speed during washing and drying and rotates in one direction at high speed during dehydration, and is connected to the drum 3 via large and small pulleys 7, 8 and a belt 9.

Reference numeral 10 is a magnet attached to the back side of the large pulley 7, 11 is a reed switch attached to a portion of the outer tub 2 facing the magnet 10, and the magnet 1
It turns on when 0 approaches, and turns off when 0 separates. That is,
When the drum 3 (large pulley 7) makes one revolution, the reed switch 11 is turned on and off once.

Reference numeral 12 denotes a temperature detecting element such as a thermistor attached to the coil portion of the motor 6, which detects the temperature of the coil portion and converts it into an analog voltage value. Although the temperature of the coil portion is detected in this embodiment, it may be the ambient temperature of the motor 6 or the temperature of the frame.

FIG. 4 shows a drive circuit for rotating the drum 3, and 13 is an inverter circuit for determining the frequency and amplitude of the voltage applied to the motor 6, which is PWM.
A first microcomputer (hereinafter referred to as a first microcomputer) 14 for generating a signal, an IGBT module (Insula)
Ted Gate Bipolar Transistor Module) 15 and an interface 16 connecting the two. The IGBT module 15 includes a driver unit 1
7, an amplifier unit 18 that controls the operation of the driver unit 17 based on the PWM signal from the first microcomputer 14, an abnormal temperature detection unit 19, an overcurrent detection unit 20, and both detection units 1
It comprises a protection circuit 21 which relays the signals from 9 and 20 and sends the signals to the amplifier section 18. When the amplifier section 18 receives a signal from the protection circuit 21, it stops driving the driver section 17. The interface 16 is composed of photocouplers 22 ... Reference numeral 23 is an RCC (Ringing Choke Converter) power supply circuit, 24 is a constant voltage circuit that supplies a constant voltage of 5 V to the first microcomputer 14, and 25 is a bias unit that supplies a reverse bias voltage to the amplifier unit 18.

Reference numeral 26 is a bridge circuit for rectifying a commercial voltage of 200 V AC, and 27 is a smoothing capacitor for smoothing the output of the bridge circuit 26 to convert it into a direct current. An overvoltage protection circuit 28 discharges the capacitor 27 when it detects an overvoltage.

As shown in FIG. 5, the first microcomputer 14 has a CPU 29 (central processing unit), as well known in the art.
RAM30 (random access memory), ROM31 (re
ad only memory), a timer 32, a system bus 33, and input / output ports 34 and 35.

The CPU 29 includes a control unit 36 and an arithmetic unit 3
7, the control unit 36 fetches and executes instructions, and the arithmetic unit 37 receives data from an input device or a memory in response to a control signal from the control unit 36 at the instruction execution stage. On the other hand, arithmetic processing such as binary addition, logical operation, increase / decrease and comparison is performed. RAM 30
Is for storing data about the device,
The ROM 31 is configured to read in advance means for operating devices, setting conditions for determination, rules for processing various information, and the like.

It should be noted that the reed switch 11 is turned ON-O.
The FF signal is input to the first microcomputer 14 via a monostable multivibrator or the like, and the first microcomputer 14 calculates the rotation speed of the drum 3 from the ON-OFF cycle of the reed switch 11.

In the above drive circuit, when the commercial power supply voltage (AC200V) is applied, the bridge circuit 2
It is converted to a direct current by 6, smoothed by a smoothing capacitor 27 and input to the IGBT module 15. At this time, the DC voltage is also input to the RCC power supply circuit 23 at the same time, and the circuit 23 receives the 5V constant voltage circuit 24 and the I voltage.
Amplifier unit 18 of GBT module 15 and protection circuit 2
Make a power supply for 1.

On the other hand, the first microcomputer 14 has a sine wave phase angle of 6 degrees in the ROM 31 in the inside thereof.
A quantized rectangular digital signal that is proportional to the amplitude of the sine wave is stored over 00 ° (5/3 period), and 0 to 3 of the 6000 continuous pattern rectangular wave signals are stored.
The U-phase, the V-phase, and the W-phase are assigned in the ranges of 60 °, 120 to 480 °, and 240 to 600 °, and a predetermined rectangular wave signal is read out from them at any time. The read rectangular wave signal is passed through the interface unit 16 to the IGBT.
It is supplied to the amplifier unit 18 in the module 15, drives the amplifier unit 18, and activates the driver unit 17.
In the driver section 17, each switching element constituting the same repeats conduction / non-conduction in accordance with the rectangular wave signal, creates a three-phase alternating current of a predetermined frequency, and outputs it to the motor 6.

FIG. 6 shows the output waveform (line voltage waveform) of each phase output from the IGBT module and the U-V phase line voltage waveform. Here, the rectangular voltage waveform of each phase corresponds to the AC voltage waveform shown by the curve.

Now, for example, if the continuous 6000 rectangular wave signals of the first microcomputer 14 are sequentially read every five, and the number of rectangular wave signals per cycle of each phase is 1200, the PWM switching frequency Is set to 15 kHz, an alternating current of 15000/1200 = 12.5 Hz can be obtained. That is, by adjusting the number of rectangular wave signals read from the first microcomputer 14, the IBG
An AC voltage having an arbitrary frequency is output from the T module 15.

Further, the amplitude (magnitude of voltage) of the AC voltage output from the IGBT module 15 is the first
It is changed by dividing the data of the rectangular wave signal in the microcomputer 14 for each data and changing the width of each rectangular wave at the same ratio.

FIG. 7 shows an output voltage waveform in which the rectangular wave signal data for outputting the voltage waveform of FIG. 6 is changed and the amplitude thereof is reduced.

Therefore, the inverter circuit 13 can drive the motor 6 at a desired rotation speed and torque.

FIG. 8 shows a control mechanism of the washing machine,
A second microcomputer (hereinafter referred to as a second microcomputer) 38 is a conversion circuit 4 including various input key circuits 39, an A / D converter, etc., and connected to the temperature detecting element 12.
0, water level sensor 41, dehydration safety top switch 42, load detection circuit 43, drying heater 44, water heater 45
The inverter circuit 1 based on input information from
3, automatic water supply valve 46, automatic drainage valve 47, buzzer circuit 4
8. A control signal is output to the dry air blowing fan 49, the display device 50, and the like.

The configuration of the second microcomputer 38 is similar to that of the first microcomputer 14.

The temperature data of the analog value output from the temperature detecting element 12 is converted into a digital voltage value by the conversion circuit 40 and input to the second microcomputer 38. A reference value corresponding to a predetermined temperature is stored in the ROM of the second microcomputer 38.
Compares the input digital voltage value with this reference value to determine whether the temperature detected by the temperature detecting element 12 (the temperature of the coil portion of the motor 6) has exceeded a predetermined temperature.

The operation of the washing machine of this embodiment based on the above construction will be described with reference to FIG. One of the keys connected to the input key circuit 39 is loaded with laundry in the drum 3.
When a start key (not shown) is pressed, water is first supplied into the drum 3, and when this is finished, the washing process is started.

The second microcomputer 38 outputs a command signal to the inverter circuit 13 to start the motor 6. IGBT module 15 of the inverter circuit 13
Outputs an initial drive voltage (initial voltage) in order to rotate the drum 3 (motor 6) at a set rotation speed (rotation speed of the drum 3 = 50 rpm) in the washing step. Then,
The motor 6 is activated to increase the rotation speed (S-
1).

The magnitude of the power supply voltage can vary depending on the region and time zone. For example, AC200V is AC.
Although it may be 190V, the initial voltage is 4K if the power supply voltage is lowered in this way and the laundry in the washing tub is the rated full amount (for example, 4Kg washing machine.
Even in the case of g), the magnitude is such that the motor 6 can generate a torque for starting without any trouble.

Here, the motor 6 rotates steadily at the set rotation speed in a state where no laundry is put in. However, in the state where there is laundry, the motor 6 will rotate steadily at a rotational speed slightly lower than the set rotational speed, depending on the torque at that time and the amount of laundry (load on the motor 6). ..

Now, a reference rotational speed P _RE that can sufficiently exert the effect in the washing process is determined. This is a rotational speed slightly lower than the set rotational speed, and when the initial voltage is applied to the rated amount as described above, the drum 3 (motor 6) rotates steadily at the reference rotational speed _PRE. I shall.

At the same time when the motor 6 is started, the first microcomputer 14 starts detecting the rotational speed P of the drum 3 (motor 6) by the reed switch 11 (S-2).

For example, when the amount of laundry this time is smaller than the rated amount, the drum 3 (motor 6) rotates steadily at a rotational speed slightly higher than the reference rotational speed _PRE . When this is detected, the second microcomputer 14 reduces the drive voltage output from the IGBT module 15 in order to reduce the torque so that the rotation speed P of the drum 3 (motor 6) becomes the reference rotation speed _PRE. (S-3, S-4).

The second microcomputer 14 is the temperature detecting element 1
2, the temperature of the coil portion of the motor 6 is detected, and the temperature is compared with the predetermined temperature as described above (S-5).

The predetermined temperature is a value lower than the upper limit value of the temperature (operation guarantee temperature) that can guarantee the normal operation of the motor defined by the JIS standard, and is a value that cannot be reached in the normal case. .. In the three-phase induction motor 6 of this embodiment, the operation guarantee temperature is set to 115 ° C. or lower depending on the type of coil used, and the predetermined temperature is set to 110 ° C. based on this.

When the temperature of the coil is 110 ° C. or lower,
The second microcomputer 38 outputs a motor stop signal to the inverter circuit 13 when 15 seconds have elapsed from the start of the motor 6 (S-6).

On the other hand, the temperature of the coil portion becomes 110 because the high voltage is continuously applied while the ambient temperature is high.
When the temperature exceeds ℃, the second microcomputer 38 sends a motor stop signal to the inverter circuit 13 after 13 seconds from the start of the motor.
To (S-7).

The inverter circuit 13 receives the stop signal, stops the output of the drive voltage, and stops the motor 6 (S-8). Next, if the washing time preset by the user has not elapsed, after 3 seconds, the second
Upon receiving the reverse activation signal from the microcomputer 38, the motor 6 is reversely activated (S-9 to S-11).

These operations are repeated, and the drum 3 reciprocally rotates. Inside the drum 3, the laundry is swept up by a baffle (not shown) bulged from the inner wall of the drum 3 and then dropped to perform a wash wash. Be seen. Then, when the washing time elapses, the washing process ends.

The ratio of the rest-rotation time after the temperature exceeds the predetermined temperature (13 seconds ON-3 seconds OFF in this embodiment) is
When the operation is continued at this ratio, it is determined by a temperature rise test or the like so that the upper limit value of the operation guarantee temperature is not exceeded.

As described above, according to the configuration of the embodiment of the present invention, the magnitude of the drive voltage of the motor 6 is adjusted according to the fluctuation of the power supply voltage and the load, and the high voltage is constantly applied to the motor 6. Since it is eliminated, the temperature rise of the motor 6 can be suppressed.

Even when a high voltage is continuously applied in a state where the ambient temperature is high, when the temperature exceeds the predetermined temperature, in one cycle operation of forward and reverse rotation with a pause,
Since the motor 6 is controlled so as to increase the ratio of the pause time, it is difficult for the temperature of the motor 6 to exceed its operation guarantee temperature.

Therefore, it is possible to prevent abnormal operation and damage of the motor 6 due to overheating.

The present invention is not limited to the above embodiment. For example, in the above embodiment, the magnitude of the drive voltage is adjusted every time the motor is started. When the rotation speed reaches the reference rotation speed, the value may be changed to the value adjusted for the first time. In such a case, the rotation speed may be detected again after the change, and if the rotation speed is different from the reference rotation speed, the rotation speed may be changed again.

Further, in the above embodiment, the amplitude is adjusted after the high voltage is first output and the motor is steadily rotated. However, the drive voltage is increased from the start of the start to the reference rotation speed. Adjustment may be performed so as to perform steady rotation at.

Further, not only in the washing step, but also in the rinsing and dehydrating steps, the number of rotations of the motor is similarly detected,
By changing the magnitude of the drive voltage, the temperature rise of the motor can be suppressed as in the above embodiment.

[0053]

According to the configuration of the present invention, the magnitude of the drive voltage of the drive motor is adjusted in response to the fluctuation of the power supply voltage and the load, so that a high voltage is always applied to the drive motor. Therefore, the temperature rise of the motor can be suppressed.

If the temperature of the drive motor exceeds a predetermined temperature during operation in the washing and rinsing step, the drive motor is increased so as to increase the ratio of the pause time in one cycle operation of forward and reverse rotation with a pause. Since the temperature is controlled, it is difficult for the temperature of the motor to exceed the operation guarantee temperature.

Therefore, it is possible to prevent abnormal operation and damage of the drive motor due to overheating.

[Brief description of drawings]

FIG. 1 is a flowchart showing an operation of a washing machine of the present invention.

FIG. 2 is a perspective view showing the outline of a washing machine.

FIG. 3 is likewise an internal mechanism diagram.

FIG. 4 is a block circuit diagram showing a drive circuit of a washing machine.

FIG. 5 is a block circuit diagram showing a configuration of a microcomputer.

FIG. 6 is a waveform diagram of an output voltage from the inverter circuit.

FIG. 7 is a waveform diagram when the amplitude of the output voltage is reduced.

FIG. 8 is a block circuit diagram showing a control mechanism of the washing machine.

[Explanation of symbols]

 6 Three-Phase Induction Motor (Drive Motor) 11 Reed Switch (Monitoring Unit) 12 Temperature Detection Element (Temperature Detection Unit) 14 First Microcomputer (Control Unit) 15 IGBT Module (Conversion Unit) 38 Second Microcomputer (Control means)

Claims (2)

[Claims] 1. Washing, rinsing, spin-drying, etc. are performed by rotating a dehydration / washing tub itself or a rotating blade arranged in this washing tub by a drive motor,
Based on information from the monitoring unit that monitors the rotation state of the drive motor, the conversion unit that changes the magnitude of the drive voltage of the drive motor, and the information from the monitoring unit, the drive motor rotates at the reference rotation speed. A washing machine comprising: a control unit that controls the operation of the conversion unit. 2. Washing, rinsing, spin-drying, etc. are performed by rotating a dewatering / washing tub itself or a rotary wing arranged in this washing tub by a drive motor.
From the control means for controlling the drive motor so as to rotate forward and backward with a pause during the washing and rinsing process, temperature detection means for detecting the temperature of the drive motor, and an upper limit temperature that can guarantee normal operation of the drive motor. The control unit includes a storage unit that stores a low predetermined temperature and a comparison unit that compares the temperature detected by the temperature detection unit with the predetermined temperature, and the control unit sets the temperature detected by the temperature detection unit to the predetermined temperature. A washing machine characterized in that when the temperature is exceeded, the ratio of the rest time in one cycle of the rest-rotation time of the drive motor is increased.