KR20090061465A - Method for detecting bubble of washing machine - Google Patents

Abstract

A method for sensing bubble in a washing machine is provided to resolve the problem that a consumer could slide by the bubble or the bubble cause fire by electric short circuit. A method for sensing bubble in a washing machine comprises: a step of measuring the variation amount of rotation number of washing machine motor during washing process; a step of comparing the variation amount of standard rotation number before the bubble generation with the variation amount of rotation number; a step of judging the generation of bubble in case that the variation amount of rotation number is less than the variation amount of standard rotation number; and a step of measuring the water level with water level sensor during the washing.

Description

Foam detection method of washing machine {METHOD FOR DETECTING BUBBLE OF WASHING MACHINE}

The present invention relates to a washing machine, and more particularly to a foam detection method of the washing machine for detecting the foam during the course of the washing course.

1 is a flowchart illustrating a method of detecting and removing bubbles during a conventional washing course.

Referring to Figure 1, the conventional washing course proceeds in the order of water supply process (S10), washing process (S11), draining process (S14), dehydration process (S15). At this time, in the washing process (S11) to detect the occurrence of bubbles using the water level sensor (S12). In general, when the water level value measured by the water level sensor is smaller than the reference water level value (23.O KHz), it is determined that bubbles have occurred. The process (S14) and the dehydration process (S15) proceeds. At this time, the bubble removing operation (S13) is made while repeating the operation of forward / reverse rotation of the drum at a low speed while supplying water.

On the other hand, the conventional method of detecting and removing bubbles during the course of washing course depends entirely on the water level value measured by the water level sensor during the washing process (S11). Therefore, when the water level sensor malfunctions, there was a problem that the foam is not normally detected during the washing process (S11).

In addition, in the case of the washing machine model without heating, or without heating, even if the bubble is generated almost no change in the water level, there was a problem that does not properly detect the foam even during the normal level sensor during washing.

In this way, if the level sensor does not properly detect the bubble, the bubble will overflow through the detergent box. In addition, even if the washing performance does not come out properly, the energy is continuously consumed, thereby increasing the consumption of unnecessary energy. In addition, when the overflowed bubbles fall to the floor, there is a problem that the consumer slips or causes a short circuit to cause a fire.

As a result, after-sales service factors increased due to foaming, which lowered the reliability of the product and caused consumer complaints.

The present invention has been made to solve the above problems, and an object of the present invention is to provide a foam detecting method of a washing machine that can accurately detect foam during washing without using a water level sensor.

In addition, it is another object to provide a foam detection method of the washing machine that can accurately detect the foam during washing by complementing the water level sensor.

Foam detection method of the washing machine according to the present invention for achieving the above object, measuring the amount of change (Δ) of the rotational speed of the washing motor during the washing course; And comparing the change amount of the rotational speed with the change amount of the reference rotational speed before foaming to determine whether bubbles are generated.

Here, it is determined that bubbles are generated when the change amount of the rotation speed is smaller than the change amount of the reference speed, and the change amount of the rotation speed is a difference between the maximum value and the minimum value of the normal rotation speed of the washing motor during the washing course. desirable.

More specifically, it is preferable to determine that bubbles are generated when the difference between the maximum value and the minimum value of the normal rotational speed is 0.5 to 0.7 times the change amount of the reference rotational speed.

On the other hand, the foam detection method of the washing machine, further comprising the step of measuring the water level of the washing water during the course of the washing course; the step of determining whether the foam is generated, the water level measured by the water level sensor If the value is smaller than the reference level value measured before foaming, it is preferable to determine that foaming has occurred.

In addition, the step of determining whether the bubble is generated, when the level value measured by the water level sensor is greater than or equal to the reference level value measured before the bubble is generated, the change in the rotational speed is less than the change in the reference rotational speed It is preferable to determine that bubbles have occurred.

In the foam preventing method of the washing machine according to the present invention described above, the foam is detected using a change amount of the rotational speed of the washing motor without detecting the foam using the level value measured by the water level sensor. Alternatively, foam is detected using both the water level value measured by the water level sensor and the amount of change in the rotation speed of the washing motor.

Therefore, it is possible to accurately detect the bubble, the conventional water level sensor does not properly detect the bubble solves the problem that the bubble flows through the detergent box. In addition, even if the washing performance is not properly produced, the energy is continuously consumed, thereby preventing the unnecessary energy consumption from being increased. In addition, the problem that the overflowing bubbles fall to the floor and the consumer slips or causes a short circuit to cause a fire.

As a result, there is no after-sales service factor due to foaming, which improves the reliability of the product and increases customer satisfaction.

Hereinafter, the foam detection method of the washing machine according to one embodiment of the present invention will be described in detail. 2 is a view showing a washing machine performing a foam detection method according to an embodiment of the present invention, Figure 3 is a flow chart showing a washing course including the foam detection method of FIG.

Referring to Figure 2, the washing machine for performing the foam detection method according to an embodiment of the present invention, the cabinet 5 to form an appearance; A tub 3 installed inside the cabinet 5 and storing wash water; A drum (9) rotatably installed in the tub (3), into which laundry is put; Washing motors 7 and 8 for rotating the drum 9; A rotating shaft 17 for transmitting the rotational force of the washing motors 7 and 8 to the drum 9; A bearing 11 supporting the rotating shaft 17; A sealing member 13 which prevents water between the tub 3 and the drum 9 from flowing into the bearing 11; Detergent supply device 30 for supplying water mixed with detergent to the tub (3); A water supply device 20 composed of a plurality of valves for supplying or blocking water to the detergent supply device 30; A drain pump 40 for pumping out water stored in the tub 3 to the outside; A water level sensor 50 installed below the tub 3 to measure the level of the wash water in the tub 3; It includes; a control panel 70 for receiving the operation command of the user to control the operation of the washing machine.

A door 1 is installed in front of the cabinet 5, and a gasket 2 is installed between the door 1 and the tub 3.

A locking spring 4 for supporting the tub 3 is installed between the inner side of the upper surface of the cabinet 5 and the upper side of the outer circumferential surface of the tub 3, and the inner side of the lower surface of the cabinet 5 and the outer circumferential surface of the tub 3. A friction damper 10 is provided between the lower sides to damp the vibration of the tub 3.

Inside the drum 9, a plurality of lifters 9a for lifting and lowering laundry are provided.

The washing motors 7 and 8 rotate on the outer circumferential surface of the stator 7 and the stator 7 having the coil wound in the slot by a direct motor, and the rotor 8 having the permanent magnet 12 therein. It consists of.

The stator 7 is fastened to the rear wall of the tub 3 by a plurality of fastening members 19.

The rotor 8 is fastened to the rear end of the rotation shaft 17 by a fastening member 18.

When power is supplied to the coil of the stator 7 and electromagnetized, the rotor 8 is rotated by interaction with the permanent magnet 12 attached to the inside of the rotor 8. The rotational force of the rotor 8 is transmitted to the drum 9 via the rotation shaft 17.

The bearings 11 are respectively installed in front of and behind the rotary shaft 17 to rotatably support the rotary shaft 17.

The sealing member 13 is inserted into and installed on the outer circumference of the rotating shaft 17 to block water between the tub 3 and the drum 9 from penetrating into the bearing 11.

The detergent supply device 30 mixes the supplied water and detergent and supplies the tub 3 to the tub 3 through the supply pipe 31. The detergent supply device 30 may be configured as follows as an example. That is, the detergent supply device 30 may be configured in a case and a detergent container installed inside the case and storing various detergents.

The siphon tube (siphon) is formed on the bottom of the detergent container, a supply port connected to the connection pipe 22 is formed on the upper side of the case, the detergent outlet is connected to the supply pipe 31 is formed at the bottom of the case.

With the above-described configuration, the water supplied through the connecting pipe 22 is mixed with the detergent stored in the detergent container, and then exits the detergent container through the siphon tube when the water level reaches a predetermined level. Water mixed with the detergent exiting the detergent container is supplied to the tub (3) through the supply pipe (31).

The water supply device 20 is provided with a supply pipe 21 connected to an external water supply source (hot or cold water), and a connection pipe 22 connected to the detergent supply device 30.

The drain pump 40 is provided with a drain pipe 41 connected to the lower side of the tub 3 and a connection pipe 42 connected to an external drain hole, respectively.

The water level sensor 50 is a core for changing the inductance value of the coil by moving up and down by the body and the coil accommodated inside the body, the washing water level, as disclosed in the applicant's patent (10-042512) And a core holder for accommodating the core, and a pressure transmitting means such as a bellows or a diaphragm.

2 and 3, the washing course proceeds in the order of water supply process (S20), washing process (S21), drainage process (S24), dehydration process (S25). At this time, the washing process (S21) to detect the occurrence of the foam by using the rotation speed change amount of the washing motor (7,8) (S22).

4 is a graph showing the maximum value and the minimum value of the normal rotational speed of the washing motor in the case of no foam generated during the washing process of Figure 3, Figure 5 is a washing motor in the case of foam generated during the washing process of Figure 3 Is a graph showing the maximum and minimum values of the normal rotation speed.

2 and 4, the change amount of the rotation speed is a difference Δ between the maximum value Nmax and the minimum value Nmin of the normal rotation speed N of the washing motors 7 and 8. Here, the normal rotational speed is the rotational speed of the washing motor (7, 8) required to proceed the washing process (S21).

If no foam is generated during the washing process (S21), the rotation speed of the washing motors (7, 8) is between the maximum (56) to 54 RPM and the minimum (46) to 45 RPM, and the washing motor (7, The difference (Δ) between the maximum and minimum values of the normal speed in 8) is between 8 and 11 RPM.

On the other hand, referring to Figure 5, when foaming occurs during the washing process (S21), the rotation speed of the washing motor (7, 8, see Figure 2) between the maximum (53) RPM (Min) 48 ~ 46 RPM And the difference Δ between the maximum and minimum values of the normal rotational speed of the washing motors 7, 8 and 2 is between 5 and 11 RPM.

That is, the difference (Δ) between the maximum value and the minimum value of the normal rotation speed when no foam is generated during the washing process (S21) is 0.5 between the difference (Δ) between the maximum value and the minimum value of the normal rotation speed when the foam is generated. It can be seen that it is ~ 0.7 times.

As compared with the case where no foam is generated during the washing process (S21), the case where the foam is smaller than the difference Δ between the maximum value and the minimum value of the normal rotation speed is as follows.

If no foam is generated during the washing process (S21), the laundry rubs against the inner wall of the drum 9, and the friction force causes more force to rotate the drum 9. For this reason, the difference between the maximum value Max and minimum value Min of the normal rotation speed of the washing motors 7 and 8 becomes large.

On the other hand, if foam is generated during the washing process (S21), since the laundry is floated by the foam inside the drum 9, the degree of friction with the inner wall is reduced, so that less force is required to rotate the drum 9. do. For this reason, the difference between the maximum value Max and minimum value Min of the normal rotation speed of the washing motors 7 and 8 becomes small.

Referring to FIG. 3, it is determined that bubbles are generated when the change amount of rotation speed is smaller than the change amount of the reference rotation speed, the washing process S21 is ended, the foam removal operation S23 is performed, and the drainage process is performed again. S24) and proceed with the dehydration process (25).

Here, the reference rotation speed change amount is the difference between the maximum value Max and the minimum value Min of the normal rotation speeds of the washing motors 7 and 8 that are measured in advance when no bubbles are generated and stored in the microcomputer (not shown). Δ, see FIG. 4).

The bubble removing operation S23 is performed while repeating the operation of rotating the drum 9 (see FIG. 2) forward and backward at low speed while supplying water through the water supply apparatus 20 (see FIG. 2).

In this way, by detecting the foam using the rotation speed change amount of the washing motor, it is possible to accurately determine whether the foam is generated irrespective of the malfunction of the water level sensor (50, see FIG. 2) and the temperature conditions according to the presence or absence of the heater.

6 is a flow chart showing a washing course including a foam detection method according to another embodiment. 2 and 6, the washing course proceeds in the order of water supply process (S30), washing process (S31), drainage process (S35), dehydration process (S36). At this time, in the washing process (S31) it is detected whether the foam is generated using the rotation speed change amount of the water level sensor 50 and the washing motor (7,8) (S32, S33).

First, when the water level value measured by the water level sensor 50 is smaller than the reference water level value (23.O KHz), it is determined that bubbles have occurred (S32), and the ongoing washing process (S31) ends and the bubble removing operation ( After performing the step S34) again proceeds to the drainage process (S35) and dehydration process (S36).

However, even if the water level value measured by the water level sensor 50 is equal to or larger than the reference water level value (23.O KHz), the drainage process (S35) and dehydration process (S36) do not proceed as it is.

That is, whether the bubble is generated again by using the rotation speed change amount of the washing motors 7, 8 so that the bubble can be accurately detected regardless of the temperature condition according to the malfunction of the water level sensor 50 and the presence or absence of the heater. It is made (S33).

Since the method of detecting the generation of bubbles using the rotation speed change amount of the washing motors 7 and 8 has been described above, it will be omitted.

In this way, by detecting the bubble by using both the water level value measured by the water level sensor 50 and the amount of change in the number of revolutions of the washing motors 7, 8, temperature conditions according to the malfunction of the water level sensor 50 and the presence or absence of a heater Regardless of whether or not bubbles are generated, it is possible to determine more accurately.

1 is a flow chart illustrating a method of detecting and removing bubbles during a conventional washing course;

2 is a view showing a washing machine performing a foam detection method according to an embodiment of the present invention,

3 is a flow chart showing a washing course including the foam detection method of FIG.

4 is a graph showing the maximum value and the minimum value of the normal rotation speed of the washing motor when no foam is generated during the washing process of FIG.

5 is a graph showing the maximum value and the minimum value of the normal rotational speed of the washing motor in the case of foam generated during the washing process of FIG.

6 is a flow chart showing a washing course including a foam detection method according to another embodiment.

<Explanation of symbols for the main parts of the drawings>

3: tub 9: drum

7,8: washing motor 50: water level sensor

Claims (7)

Measuring a change amount Δ of the rotation speed of the washing motor during the washing course; And And comparing the change amount of the rotational speed with the change amount of the reference rotational speed before foaming to determine whether bubbles are generated. The foam sensing method of claim 1, wherein when the change amount of the rotation speed is smaller than the change amount of the reference speed, bubbles are generated. The method of claim 1, further comprising: measuring the water level of the washing water during the course of the washing course with a water level sensor. The method of claim 3, wherein the determining of whether the bubble is generated comprises: The bubble detection method of the washing machine to determine that the bubble is generated when the level value measured by the water level sensor is smaller than the reference level value measured before the bubble is generated. The method of claim 3, wherein the determining of whether the bubble is generated comprises: The bubble detection method of the washing machine determines that the bubble is generated when the water level value measured by the water level sensor is greater than or equal to the reference water level value measured before the bubble is generated, and the amount of change in the rotation speed is smaller than the amount of change in the reference speed. The method for detecting foam of a washing machine according to any one of claims 1 to 5, wherein the change amount of the rotation speed is a difference between the maximum value and the minimum value of the normal rotation speed of the washing motor during the washing course. The method of claim 6, wherein the foam is detected when the difference between the maximum value and the minimum value of the normal rotational speed is 0.5 to 0.7 times the change amount of the reference rotational speed of the washing machine.

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