KR20000014588A - Bubble detecting method of drum washing machine - Google Patents

Abstract

PURPOSE: A bubble detecting method of a drum washing machine is provided to improve the exact of a bubble detection, and to extend the life of a motor. CONSTITUTION: The bubble detecting method of the drum washing machine contains: a phase angle judging step to judge if an early phase angle of a motor driving voltage supplied to a motor by a motor driving unit is over an established phase angle by performing a dehydration; a count and RPM judging step to count a maintaining time maintained the motor driving voltage under the established phase angle by a timer when the early phase angle of the motor driving voltage is under the established phase angle, and to judge if the RPM of the present motor inputted through a motor speed sensor is under an established RPM; a step to judge a bubble excessive state if the maintaining time is over the established time and the RPM of the motor is under the established RPM as the result of the count and RPM judging step.

Description

Foam detection method of drum washing machine

The present invention relates to a washing machine, and more particularly, to a foam detecting method of a drum washing machine.

Generally, a washing machine is a machine for washing laundry by performing washing, rinsing, and dehydrating strokes according to a predetermined algorithm. The washing machine is classified into a pulsator type, a stirring type, a drum type, and the like according to a washing method.

At this time, the drum washing machine has been widely used, with the advantage of lowering the damage rate of laundry and the lowest use quantity, compared to other types of washing machines. As shown in FIG. 1, a damper (not shown) inside the main body 1 and the main body 1 is shown. Tub (2) elastically supported by the), the laundry is put into the tub (2) and the drum (3), the drum associated with the washing operation by receiving the driving force of the motor 10 through the belt (11) to rotate The first thermistor (4) for measuring the temperature of the wash water supplied to (3), the detergent container (5) for injecting detergent, the detergent container (5) is connected to the washing water or detergent of the detergent container (5) is mixed A water supply pipe 6 for supplying the washing water, a drain pipe 7 for discharging the washing water used in the washing stroke to the outside, a pump 8 and a drain hose connected to the ends of the drain pipe 7 for forcibly pumping the washing water. It is comprised including (9).

And when looking at the operation of the drum washing machine configured as described above, first, when the user opens the door (not shown) attached to the front of the main body 1, puts the laundry, and inputs the washing command through the control panel, the washing water is the detergent container (5). Guided by the water supply pipe (6) through the) is filled in the drum (3).

Subsequently, the water level sensor (not shown) detects the water level in such a manner that the oscillation frequency is changed according to the water pressure of the washing water filled in the drum 3, and outputs the water level detection frequency to the controller.

At this time, the water level sensor generates a water level detection frequency of about 21KHz ~ 26KHz in inverse proportion to the current washing water level (high ~ low).

The controller determines whether water supply is completed up to a predetermined level according to the water level detection frequency output from the water level sensor, and when the water supply is completed up to the set water level, drives the motor 10 to rotate the drum 3 to proceed with washing. do.

On the other hand, when the washing is completed, the pump 8 is operated so that the washing water is drained to the outside via the drain pipe 7 and the drain hose 9, and when the draining is completed, the rinsing and dehydrating stroke are continuously performed, and the washing administration is finished. do.

In this case, the drum washing machine puts detergent together with the washing water in the laundry administration, and washes by left / right stirring, so many bubbles are generated when dehydration administration is performed by the detergent component remaining in the laundry after draining. It acts as a load between the tub (2) to inhibit the driving of the motor 10, so that it does not reach the normal dehydration RPM.

Therefore, there is a need for an apparatus for accurately detecting the occurrence of a large amount of bubbles to affect the dehydration stroke and performing a proper operation such as bubble removal.

Hereinafter, with reference to the accompanying drawings, look at the foam detecting method of the drum washing machine according to the prior art as follows.

Figure 2 is a flow chart showing a foam detecting method of the drum washing machine according to the prior art.

In the foam washing method of the drum washing machine according to the related art, first, when a user opens a door, inputs laundry, and inputs a washing command, ie, a washing mode such as a washing mode, through a control panel, the controller corresponds to the input washing command. Carry out a wash or rinse stroke to

When the rinsing stroke is completed, as shown in FIG. 2, dehydration is started (S11).

Subsequently, it is determined whether or not the water level detection frequency output from the water level sensor is a set frequency, that is, 22.5 KHz or less (S12). If the water level detection frequency is less than or equal to the set frequency, the bubble is detected as a transient state (S13). S14).

In this case, the dehydration stroke is a state in which the washing water is drained, so that the water level detection frequency is 22.5 KHz or less, so the water level detection frequency generated by the pressure of the bubble generated in the dehydration stroke is detected as a bubble transient state.

And while performing the water supply and drainage at the same time by performing a left / right stirring three times the drum (3) to remove the foam (S15).

Subsequently, rehydration is performed (S11), and the judging unit detects whether the water level detection frequency is lower than or equal to the set frequency (S12). If the water level detection frequency is larger than the set frequency, it is determined that the bubbles inside the tub (2) are removed. Judging (S16), when the dehydration is completed, the administration before washing ends.

The foam washing method of the drum washing machine according to the prior art detects that the foam is excessive only when it is below a specific water level frequency. Since it is determined that it is not excessive, the dehydration operation is continuously performed, and thus the dehydration performance is deteriorated due to the foam acting as a load between the drum and the tub, so that the dehydration performance is deteriorated and the foam remains in the laundry after the end of the washing.

Accordingly, an object of the present invention is to provide a foam washing method for a drum washing machine, which is designed to solve the above-described problems and to improve the accuracy of foam sensing.

1 is a cross-sectional view showing the structure of a general drum washing machine

2 is a flow chart showing a foam detecting method of the drum washing machine according to the prior art.

Figure 3 is a flow chart illustrating a foam detection method of the drum washing machine according to the present invention

Figure 4 is a block diagram showing the linkage configuration for controlling the motor drive of the drum washing machine according to the present invention

5 is a waveform diagram illustrating a method of controlling a motor driving voltage phase angle according to the present invention;

Figure 6 is a graph showing the change in motor RPM during dehydration operation according to the present invention

Explanation of symbols for main parts of the drawings

10: motor 32: speed sensor

33: microcomputer 34: motor drive unit

41: constant speed control unit 42: timer

The present invention relates to a drum washing machine including a motor driving unit, a motor, a timer, and a motor speed sensor. If the initial phase angle of the motor driving voltage is less than the set phase angle as a result of the phase angle judgment step and the phase angle judgment step, the holding time that the motor drive voltage is kept below the set phase angle is counted by a timer and input through the motor speed sensor. The count and RPM determination step of determining whether the current motor RPM is less than the set RPM, and the determination result of the count and RPM determination step is determined to be a bubble transient state if the retention time is more than the set time and the RPM of the motor is less than the set RPM. Characterized by comprising a step.

Hereinafter, with reference to the accompanying drawings, look at the foam detecting method of the drum washing machine according to the present invention.

Figure 3 is a flow chart showing a foam washing method of the drum washing machine according to the present invention, Figure 4 is a block diagram showing the linkage configuration for controlling the motor drive of the drum washing machine according to the present invention, Figure 5 is a motor drive according to the present invention FIG. 6 is a waveform diagram illustrating a voltage phase angle control method, and FIG. 6 is a graph illustrating changes in RPM during dehydration operation according to the present invention.

In the foam washing method of the drum washing machine according to the present invention, first, when a user opens a door, puts laundry, and inputs a washing instruction, ie, a washing mode, such as a washing mode, through a control panel, the controller corresponds to the input washing instruction. Carry out a wash or rinse cycle.

Subsequently, when the rinsing stroke is completed, as shown in FIG. 3, the dehydration stroke is started by rotating the motor 10 at a predetermined RPM (revolutions per minute) (S31).

At this time, look at the linkage configuration for controlling the RPM of the motor 10, as shown in Figure 4, the speed sensor 32, the speed sensor 32 for sensing the motor RPM every half cycle of the motor driving voltage waveform shown in FIG. The output motor RPM is compared with the preset motor RPM (hereinafter, referred to as set RPM) at the time of normal dehydration to increase or decrease the RPM by the difference value, so that the current motor RPM is approached to the set RPM shown in FIG. 5. A motor drive having a constant speed controller 41 for controlling the initial phase angle P of the motor driving voltage, a controller 33 having a timer 42, and an initial phase angle P output from the constant speed controller 41. It consists of a motor drive part 34 for applying a voltage to the motor 10.

At this time, the constant speed control unit 41 decreases the initial phase angle P of the motor driving voltage so that the RPM as much as the difference value can be increased if the current RPM is less than or equal to the set RPM. The motor constant speed control operation is performed by increasing the initial phase angle P of the motor driving voltage so that the RPM of the motor can be reduced.

Therefore, in the normal dehydration stroke without excessive foaming, there is no load factor that reduces the motor RPM, so the motor RPM approaches the set RPM and the initial phase angle (P) does not decrease below a certain level. Set the minimum initial phase angle (P) in the stroke to 30 ° (hereinafter referred to as the set phase angle) so that when the initial phase angle (P) of the actual motor drive voltage falls below the set phase angle, So you want to detect whether or not bubbles.

When returning to the original subroutine to which the above-described bubble detection principle is applied, it is determined whether the initial phase angle P of the motor driving voltage is less than or equal to the set phase angle (S32).

Subsequently, when the determination result (S32), the initial phase angle (P) of the motor drive voltage is less than the set phase angle, the time the state is maintained using the timer 42 is counted (S33).

Then, it is determined whether the current motor RPM detected by the speed sensor 32 is larger than the set RPM (S34), and if the current motor RPM is larger than the set RPM, the count value of the timer 42 is reset to '0' ( S39).

At this time, the set RPM is set to about 150 RPM lower than the normal dehydration RPM (for example, the set RPM is 650 when the normal dehydration RPM is 800), as shown in Figure 6, lowered by the bubble transient state Although it is higher than dehydration RPM and has not reached the normal dehydration RPM, it sets the speed that the bubble present in the tub (2) can be discharged to the outside by the speed. I do not need to do that.

On the other hand, the determination result (S34), if the current motor RPM is less than the set RPM determines whether the count value of the timer 42 exceeds the set time (S35), if the count value exceeds the set time bubble transient state Detect (S36) and stop dehydration (S37).

On the other hand, if the count value does not exceed the set time in the determination result (S35), the process returns to the subroutine (S32).

Subsequently, the drum 3 is left / right stirred three times while simultaneously supplying water and draining water to remove bubbles (S38).

Then, after rehydration is performed (S31), the subroutines (S32 to S39) are performed to determine whether or not dehydration is completed (S40).

Foam detection method of the drum washing machine according to the present invention has the following effects.

First, the bubble transient state, which acts as a load in the tub and drum and causes the motor RPM change, is sensed according to the change of the motor driving voltage phase angle control value, thereby improving the accuracy of the bubble detection.

Second, since the bubble detection is accurate, the dehydration performance is improved and the life of the motor can be extended by preventing the overload of the motor due to the incorrect bubble detection.

Claims (4)

In a drum washing machine having a motor driving unit, a motor, a timer, and a motor speed sensor, A phase angle determination step of determining whether an initial phase angle of the motor driving voltage supplied to the motor by the motor driving unit is greater than or equal to a set phase angle by performing dehydration; If the initial phase angle of the motor driving voltage is less than the set phase angle as a result of the determination of the phase angle determination step, the current is inputted through the motor speed sensor and counts the holding time that the motor driving voltage is kept below the set phase angle. A count and RPM determination step of determining whether the RPM of the motor is less than or equal to the set RPM; Determination of the count and RPM determination step of the foam washing method of the drum washing machine comprising the step of determining if the holding time is more than the set time and the RPM of the motor is less than the set RPM. The method of claim 1, And a step of resetting the timer if the RPM of the current motor is greater than or equal to the set RPM as a result of the determination of the count and RPM determination step. The method of claim 1, And resetting the timer when the RPM of the current motor is less than the set RPM and the initial phase angle is less than the set phase angle as the determination result of the counting and RPM determination step. The method of claim 1, The set RPM in the counting and RPM determination step is a predetermined level lower than the normal dehydration RPM and foam detection method of the drum washing machine, characterized in that the RPM which can discharge the bubbles present in the washing machine to the outside.