JP2001212397A - Bubble sensing method for washing machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a bubble sensing method for washing machine for sensing the existence of a large amount of bubbles while sensing a fluctuation of voltage by the motor current to be changed in response to the quantity of bubble and for eliminating the bubbles while performing the feedback to a rinse process when the generation of bubbles is determined. SOLUTION: This bubble sensing method includes a process for sensing a voltage by the motor driving current when dewatering the washing, and a process for determining existence of the generation of bubbles while comparing the sensed voltage with a present reference value so as to determine the generation of bubbles. When the voltage by the motor driving current exceeds the reference value during the hydrating operation, the dewatering operation is interrupted, and a feedback to the rinse process is performed so as to eliminate the bubble.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for detecting bubbles in a washing machine, and more particularly, to detecting a voltage change caused by a motor current depending on the amount of bubbles to detect the presence or absence of bubbles.
The present invention relates to a bubble sensing method of a washing machine for removing bubbles by feedback to a rinsing process when bubbles are determined to be generated.

[0002]

2. Description of the Related Art Generally, as shown in FIG. 1, a drum washing machine is provided with a detergent tube 3 and an operation unit 5 at an upper portion of a front surface of a main body 1 of the drum washing machine. A hot water supply valve 7 and a cold water supply valve 8 are provided so as to supply hot water and cold water, which are connected to a tap (not shown).

[0003] A tab 9 is provided in the main body 1, and a drum 11 that rotates at a high speed so as to wash and dehydrate the loaded laundry is provided in the tab 9.
A partition plate 15 is provided on the front surface of the tub 9 so as to bind a door 13 which is opened and closed when the laundry is put into or taken out of the drum 11, and the front surface of the tub 9 is used for washing and spinning. An equilibrium weight 19 for preventing vibration generated when the drum 11 rotates at a high speed is provided.

An air vent 17 is provided above the partition plate 15 so as to allow dry air to flow during the drying process of the laundry, and a drying heater 21 for drying the air introduced from the outside into the air vent 17. Is provided,
One side of the drying heater 21 has the drying heater 21
The high heat generated from the drum 11
Is provided with a fan motor 23 for blowing air.

[0005] A condensing hose 25 for supplying cold water to condense the dry air due to the high heat of the drying heater 21 flowing into the tub 9 is connected to the outer peripheral surface of the tub 9. On the lower side is the drum 11
-Phase induction motor of power generation means for rotating the motor forward and reverse
(Hereinafter referred to as motor) 27 is provided.

A drainage pump 29 for discharging the washing water in the tub 9 through a drainage hose (not shown) is provided at a lower portion on the back surface of the main body 1. At the same time, it is possible to prevent the drain pump 29 from being clogged by the washing water such as residual water and filth flowing out of the tub 9 and, when the drain pump 29 cannot be operated due to a power failure, a filter 31 for draining the washing water is provided. Is provided.

The drum 11 has a plurality of through holes 11a formed on the entire surface thereof so that the laundry can be rolled in the drum 11 and the washing water in the tub 9 can flow into the drum 11. The drum 11
A water flow adjusting member 11b that separates the laundry while pulling it up at a predetermined interval of 120 ° and dropping the laundry so as to perform the function of a washing bar is bound inside.

In the conventional drum washing machine configured as described above, first, a user places laundry (clothes) in the drum 11.
After inputting, the operation unit 5 is operated to obtain desired washing conditions.
(Washing type, temperature of washing water, washing course, drying time, etc.) and turn on the operation button, washing water supplied from a faucet (not shown) turns on hot / cold water supply valves 7,8. Water is supplied into the tub 9 through the tub 9.

When the washing water is supplied into the tub 9, the drum 11 rotates at a high speed while being turned left and right by the driving of the motor 27, so that a water flow is formed in the supplied washing water, and at the same time, the washing is applied to the laundry. A physical force is applied to separate the scum and foreign matter adsorbed on the laundry and follow the washing, rinsing, dehydrating and drying processes.

However, in such a conventional drum washing machine, as the dewatering RPM (rotation speed) rises during dewatering after rinsing, moisture / detergent air bubbles remaining in the laundry are temporarily discharged to the drain pump 29. If the user uses a detergent more than the standard amount or a detergent that generates a large amount of air bubbles, air bubbles are generated more than the amount drained by the drain pump 29 and the front of the drum washing machine (for example, However, there is a problem that air bubbles leak into a detergent tube.

[0011]

SUMMARY OF THE INVENTION Accordingly, the present invention has been devised to solve the above-mentioned conventional problems.
The present invention provides a method of detecting bubbles in a washing machine, which detects a voltage variation due to a motor current that varies according to the amount of bubbles to detect the presence or absence of bubbles and, if it is determined that bubbles are generated, feeds back to a rinsing process to remove bubbles. There is a purpose.

[0012]

According to the present invention, there is provided a method for detecting bubbles in a washing machine according to the present invention, comprising the steps of: The method may further include sensing a voltage value according to a driving current of the motor, and comparing the sensed voltage value with a predetermined reference value to determine the occurrence of bubbles. And

In the step of judging the presence or absence of bubble generation, it is determined that a bubble is generated when the number of times the drive current of the motor becomes equal to or more than the reference value is equal to or more than a predetermined number within a predetermined time. If it is determined in the step of determining whether or not bubbles are generated, the operation of the motor is stopped to feed back to the rinsing step to suspend the dehydration step and remove the bubbles.

In a bubble sensing device of a washing machine in which a spin-drying process is performed by a high-speed rotation of a motor, a current-sensing means for sensing a driving current of the motor and outputting a voltage signal during spin-drying, and a voltage signal output by the current-sensing means. If the voltage signal is equal to or more than a predetermined reference value for judging the occurrence of air bubbles, control means for judging the occurrence of air bubbles, interrupting the driving of the motor and feeding back to the rinsing process is provided.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below in detail with reference to the accompanying drawings. In the washing machine according to the present invention and the conventional configuration shown in FIG. 1, the same portions are denoted by the same names and the same reference numerals, and description thereof is omitted. FIG. 2 is a block diagram of a control device of a washing machine according to an embodiment of the present invention, and FIG. 3 is a detailed circuit diagram of a current sensing unit applied to the present invention.

As shown in FIG. 2 and FIG.
00 converts a commercial AC voltage supplied from the outside into a predetermined DC voltage required for the operation of the washing machine and outputs the DC voltage to each drive circuit. The operation unit 5 includes a large number of function buttons for inputting water temperature, washing course, drying time, and the like.

The driving current applied to the motor 27 changes depending on the generation of bubbles during the progress of dehydration. To explain this in more detail, if air bubbles are generated too much, they act as a kind of resistance factor on the motor, causing fluctuations in the drive current value of the motor previously set to a standard value by the designer in the manufacturing process. Such fluctuations appear more clearly in the initial stage of driving the motor shown in FIG.

The current sensing means 104 senses the drive current of the motor 27 which changes due to the generation of bubbles during the dehydration as described above.
As shown in FIG. 3, is connected to an emitter terminal of a switching element IGBT (not shown) of the motor driving unit 110, and detects a shunt resistance Rs for detecting a driving current of the motor 27 and a voltage applied to the shunt resistance Rs. A resistor R1 and a capacitor C1 that output a voltage value obtained by integrating the motor current, and a bubble sensing reference voltage value generated by the voltage dividing resistors R2 and R3 by the voltage value integrated by the resistor R1 and the capacitor C1 (for example, 2. 487V) and outputs a high or low level voltage signal to the control means 108, a resistor R6 and a capacitor C5, a reverse voltage prevention diode D1, and resistors R4, R5 and a capacitor for removing noise components. C2, C3,
C4.

The water level sensing means 106 is based on the principle that if the pressure changes due to the supply of the washing water into the tub 9, the frequency of the frequency oscillation circuit inside the water level sensor is proportionally or inversely converted. And use a general method of sensing the water level. If the motor current sensed by the current sensing means 104 is equal to or greater than a preset reference current value, the control means 108 determines that air bubbles have been generated, and when air bubbles have been generated, stops the driving of the motor 27 and feeds back to the rinsing process. The control means 108 is adapted to control when a low signal is input two or more times during a predetermined time (for example, 3 ms) from the current sensing means 104 in order to accurately detect bubble generation. While the motor 27 is stopped, feedback is made to the rinsing process to prevent malfunction due to noise. The fixed time (3
ms) can be set within 1 to 5 ms in this embodiment.

The motor driving means 110 receives the control signal output from the control means 108 and controls the motor 27 to rotate forward and reverse so that the laundry is washed and dehydrated. The hot / cold water supply valves 7 and 8 are controlled so that hot and cold water supplied from a water tap (not shown) is supplied into the tub 9 in response to a control signal from the means 108.

The drain pump driving means 114 receives the control signal output from the control means 108 and discharges the washing water in the tub 9 to the outside.
The display means 116 controls the operation of the driving operation means 1.
02, the washing condition and the operating state are displayed, and of course, the error content (for example,
(Bubble generation) is displayed.

Hereinafter, the operation and effect of the air bubble sensing method of the washing machine configured as described above will be described with reference to FIGS. 4A and 4B. FIGS. 4A and 4B are flowcharts illustrating a control operation sequence for detecting occurrence of air bubbles in the washing machine according to the present invention.

First, when power is applied to the washing machine, the power supply means 100 converts a commercial AC voltage supplied from the outside into a predetermined DC voltage required for driving the washing machine, and converts each of the driving circuits and the control means 108. Output to

Accordingly, the control means 108 receives the DC voltage output from the power supply means 100 and initializes the washing machine. At this time, in step S10, the user puts laundry (load) into the drum 11 and sets desired washing conditions (washing type, washing water temperature, washing course, drying time, etc.) via the operation unit 5. If the operation button is turned on after the input, the control means 108 controls the drum 11 in step S20.
A control signal is output to the water supply valve driving means 112 so that the washing water necessary to detect the amount of the laundry put into the tub 9 is supplied to the tub 9.

Along with this, the water supply valve driving means 112 receives the control signal output from the control means 108 and opens (turns on) the hot / cold water water supply valves 7 and 8, thereby turning on the hot water supplied from the water tap. Or cold water washing tab 9
Water is supplied inside. At this time, in step S30, the water level sensing means 106 detects the water level rising by the water supply operation accompanying the opening of the hot / cold water supply valves 7, 8, and the control means 108
When the pressure rises as the washing water is supplied, the control means 108 inputs a frequency that changes according to the principle that the frequency of the frequency oscillation circuit existing inside the water level sensor decreases, and the water level of the washing water is adjusted. Sense.

Next, in step S40, is the water level sensed by the water level sensing means 106 supplied to a set water level (a washing water level required for sensing the amount of laundry) preset in the control means 108? If the water is not supplied to the set water level, the operation returns to the step S20, and the operation from the step S20 is repeated while the hot / cold water supply valves 7, 8 are opened and water is continuously supplied until the water reaches the set water level.

If water is supplied to the set water level as a result of the determination in step S40, the process proceeds to step S50, where the control means 108
Controls the water supply valve driving means 112 to close (turn off) the hot / cold water water supply valves 7 and 8, and outputs a control signal to the motor driving means 110 so as to drive the motor 27.

Therefore, an alternating current is supplied to the motor 27 from the AC input terminal, and the motor 27 rotates left or right while
Since the drum 11 is turned left and right to form a water flow in the supplied washing water, the washing water and the detergent liquid inside the drum 11 are absorbed by the laundry (load), and the washing water level is lower than the set water level depending on the amount of the laundry. At this time, the amount of frequency increase due to the lowering of the washing water level varies depending on the amount of laundry.

Accordingly, in step S60, the control means 108 counts the time during which the motor 27 is reversed left and right by a built-in counter, and a predetermined time (the time required to determine the amount of laundry). Is determined, and if the predetermined time has not elapsed, the process returns to the step S50, and the operation after the step S50 is repeatedly performed while the motor 27 is left and right agitated continuously for the predetermined time.

If the result of the determination in step S60 is that a predetermined time has elapsed, the flow proceeds to step S70, where the control means 108 controls the motor driving means 110 to stop the left and right stirring of the motor 27, and then the water level change amount at this time. After sensing the amount of laundry (load amount) by sensing the
Water flow time, number of rinses, amount of washing water, dehydration time, etc. are determined.

Next, in steps S80 to S90, the control means 108 opens the hot / cold water supply valves 7 and 8 to turn on the hot water / cold water supply water in the tub 9, and then supplies hot water / cold water water. After closing (turning off) the valves 7 and 8, the motor 27 is driven. At the same time as the drum 11 rotates at a high speed while being rotated left and right by the driving of the motor 27, a water flow is formed in the supplied washing water, and at the same time, a physical force is applied to the laundry to remove slag adsorbed on the laundry. A washing step and a rinsing step are performed so as to separate foreign matters (S80 to S9).
0). Thereafter, in step S100, the control unit 108 outputs a control signal to the drain pump driving unit 114 to drain the contaminated washing water in the tub 9 during the washing and rinsing process.

Accordingly, the drain pump driving means 114 receives the control signal output from the control means 108 and drives the drain pump 29 to drain the contaminated washing water in the tub 9 into a drain hose (not shown). ). Subsequently, as shown in FIG. 4B, in step S110, the control unit 108 performs the intermittent dehydration step of intermittently driving the motor 27 to intermittently dehydrate the laundry one to three times, and proceeds to step S120. , The motor driving means 110 controls the motor 2 under the control of the control means 108.
By rotating the drum 7 at high speed, the centrifugal force generated while the drum 11 is rotating at high speed dehydrates the residual moisture of the laundry and starts the dewatering process.

During the dehydration, in step S130, the drive current of the motor 27, which changes due to the generation of bubbles, is sensed by the current sensing means 104 and output to the control means 108. That is,
When the motor 27 rotates at a high speed during the dehydration process, a switching element IGB (not shown) of the motor driving means 110 is used.
A shunt resistor R connected to the emitter terminal of T
The drive current of the motor 27 is applied to s, and the motor current applied to the shunt resistor Rs is equal to the resistor R1 and the capacitor C.
The voltage value resulting from the motor current is integrated as shown in FIG.

The voltage value output from the resistor R1 and the capacitor C1 is input to the inverting terminal (-) of the comparator 105, and the non-inverting terminal (+) of the comparator 105 is generated by the voltage dividing resistors R2 and R3. The bubble detection reference voltage value (2.487 V) having the waveform shown in FIG. 5 is input. Accordingly, the comparator 105 compares the voltage value of the motor current input to the inverting terminal (-) with the reference voltage value input to the non-inverting terminal (+), and outputs a high or a low voltage via its own output terminal. Outputs a low-level voltage signal. At this time, if the voltage value due to the motor current is larger than the reference voltage value, a low signal is output or a high signal is output.

More specifically, if the amount of bubbles during the dehydration is very small or no bubbles are detected in step S120, the driving current of the motor 27 applied to the shunt resistor Rs is lower than the reference voltage and the output of the comparator 105 is reduced. Goes high. However, if the amount of bubbles increases rapidly, the shunt resistance R
The output of the comparator 105 falls from high to low when the drive current of the motor 27 for s becomes higher than the reference voltage.

Therefore, the control means 108 controls the comparator 105
When a high signal is input, it is determined that a bubble has not been detected, and when a low signal is input, it is determined that a bubble has been detected. Accordingly, in step S140, the control unit 108 determines whether the motor current input from the current sensing unit 104 is a low signal, and if not, determines that no air bubbles were detected during dehydration. Proceeding to step S150, the control means 108 determines whether or not the spin-drying time predetermined by the amount of the laundry has elapsed while the motor 27 continues to rotate at a high speed.

If the dewatering time has not elapsed in the step S150, the operation returns to the step S120, and the operation from the step S120 is repeated while the motor 27 is rotated at a high speed until the dewatering time elapses and the dewatering process proceeds. on the other hand,
If the dewatering time has elapsed in step S150, the process proceeds to step S160, and the control unit 108 stops the motor 27 and ends the operation while completing all the washing steps.

If a low signal is output in step S140, the control means 108 determines that air bubbles have been detected during dehydration, and proceeds to step S20.
0, the control means 108 operates for a certain time (for example, 3 m
During s), it is determined whether the low signal has been detected a predetermined number of times (for example, twice). As described above, the reason for determining whether the low signal has been input a predetermined number of times (for example, twice) is to prevent the low signal input due to noise from being erroneously determined to be bubbles and malfunctioning. It is provided.

If the low signal is detected twice or more in step S200, it is determined that air bubbles have been correctly detected during the dehydration, and the process proceeds to step S210 to control the control unit 108.
The operation of step S90 is repeated by stopping the driving of the motor 27, returning to step S90 to remove bubbles, and performing the rinsing process. In the above-described embodiment, the reference voltage value for determining the occurrence of bubbles is 2.48.
7V, the number of low signal inputs to two, and the fixed time to 3m
Although the description has been limited to s, the present invention is not limited to this, and any number of modifications can be made by those skilled in the art.

[0040]

As described above, according to the method for detecting bubbles in a washing machine according to the present invention, when the voltage value due to the motor current, which changes due to the generation of bubbles during dehydration, is sensed and the detected voltage value is equal to or greater than a certain value. If bubbles are generated, bubbles are removed efficiently by interrupting dehydration and feeding back to the rinsing process.

In addition, the inverter control system using a three-phase induction motor according to the present invention basically has a motor protection circuit and checks the motor overload not only at the time of dehydration but also throughout the washing process. Since the generation of bubbles can be detected by using an existing circuit without adding another device (for example, a rotation speed detecting device) for the detection, the configuration is simple.

[Brief description of the drawings]

FIG. 1 is a perspective view of a conventional drum washing machine.

FIG. 2 is a block diagram of a control device of the washing machine according to one embodiment of the present invention.

FIG. 3 is a detailed circuit diagram of a current sensing unit applied to the present invention.

FIGS. 4A and 4B are flowcharts illustrating a control operation sequence for detecting generation of air bubbles in the washing machine according to the present invention.

FIG. 5 is a voltage waveform diagram according to a motor current when bubbles are generated in the washing machine according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Drum 27 Motor 29 Drain pump 100 Power supply means 102 Driving operation means 104 Current sensing means 106 Water level sensing means 108 Control means 110 Motor drive means 112 Water supply valve drive means 114 Drain pump drive means 116 Display means

Claims (5)

[Claims] 1. A method of detecting air bubbles in a washing machine, which proceeds a spin-drying process by rotating a motor at a high speed, comprising: detecting a voltage value according to a driving current of the motor when spin-drying proceeds; Determining the presence or absence of air bubbles by comparing the air bubbles with a predetermined reference value. 2. The method according to claim 1, wherein the step of determining whether or not the bubble is generated includes:
The method of claim 1, wherein the generation of air bubbles is determined when the air bubbles are generated a predetermined number of times within a predetermined time. 3. The method according to claim 1, further comprising the step of: stopping the driving of the motor and feeding back to the rinsing process to remove the bubbles if the generation of the bubbles is determined in the determining of the bubble generation. Claim 1
4. The method for detecting bubbles in a washing machine according to claim 1. 4. An air bubble detecting device for a washing machine which advances a spin-drying process by a high-speed rotation of a motor, wherein current sensing means for sensing a driving current of the motor and outputting a voltage signal during spin-drying, and output by the current sensing means. Washing means for judging the occurrence of air bubbles if the applied voltage signal is equal to or greater than a preset reference value for judging the occurrence of air bubbles, interrupting the driving of the motor, and feeding back to the rinsing process. Air bubble sensing device. 5. The current sensing means includes: a shunt resistor for sensing a drive current of the motor; a first resistor and a first capacitor for outputting a voltage value obtained by integrating a motor current applied to the shunt resistor; The second resistor and the second capacitor which output a high or low level voltage signal by comparing the voltage value with a preset reference voltage value for bubble detection, a reverse voltage prevention diode, and a noise component are removed. 5. The apparatus of claim 4, further comprising a plurality of resistors and a plurality of capacitors for performing the operation.