KR20090063372A - Washing machine and method for indicating a water level - Google Patents

Abstract

A washing machine and sensing method of water level are provided to accurately sense water even in a low water level by installing a sensor of electromagnetic field. A method for sensing water level in washing machine comprises: a step of judging whether water levels sensed in a first water level sensor and second water level sensor; and a step of finishing water supply or drainage when the water level reaches to the target level. The second water level sensor is installed at the adjust location with the target water level. The plurality of second water level sensors is installed to correspond to the target water level.

Description

Washing machine and method for indicating a water level}

The present invention relates to a washing machine, and more particularly, to a washing machine that can accurately detect the water level even in a low water level and a water level detecting method thereof.

A washing machine (usually a drum washing machine) includes a drum-type tank containing wash water and a rotating drum installed inside the tank to rotate the laundry inside the cylinder when the cylindrical rotating drum rotates. After pulling up, the washing is performed by the force of dropping.

The water level sensor normally used in the washing machine serves to detect the water level of the washing water supplied into the water tank and outputs a water level detection signal having a variable frequency according to the pressure change caused by the water level change.

When water is started in the water tank, the inductance of the coil changes according to the water pressure of the current level.When the water level increases, the inductance of the coil decreases as the water level increases. Thus, the higher the water level in the tank, the higher the water pressure, the lower the frequency f, and the lower the water level, the lower the water pressure, the higher the frequency f.

The frequency f signal according to the water level change of the tank as described above is input to the microcomputer, and the microcomputer counts the input frequency signal and stores the count value every predetermined period. Thus, the water level of the tank is detected by comparing the stored count value with the current count value.

However, since the water level sensor of the conventional washing machine is repeatedly driven by a mechanical operation, durability is inferior, and there is a big deviation in detecting the water level. In particular, in the low water level, since the level measurement value (count value) increases nonlinearly and the measurement error increases, there is a problem that it is difficult to accurately detect the water level.

Therefore, there is a problem in that it is difficult to implement a washing machine applying a low water level section such as supplying a small amount of washing water to a washing machine without a drying function and providing a deodorizing function by heating with a heater.

The present invention for achieving the above object is a step of determining whether the washing water level measured by the first water level sensor and the washing water level detected by the second water level sensor when the water supply or drainage of the washing machine reaches the target water level, and two washing water levels When the reaches the target water level, the step of terminating the water supply or drainage of the washing machine.

Here, the second water level sensor is installed at a position close to the target water level, and if a plurality of target water levels exist according to the washing stroke, a plurality of second water level sensors are installed to correspond to the target water level.

In addition, in the determining step, when the measured value measured by the first water level sensor is within an error range of the target water level, and a detection signal is detected by the second water level sensor, it is determined that the washing water level has reached the target water level.

In addition, the determination step may further determine whether the first level sensor or the second level sensor is faulty using the measured value measured by the first level sensor and the detection signal detected by the second level sensor.

That is, in the determining step, if the measured value measured by the first level sensor exists within the error range of the target level but the detection signal is not detected by the second level sensor, it is determined that the second level sensor is faulty.

In addition, in the determining step, if the detection signal is detected by the second level sensor, but the measured value measured by the first level sensor does not exist within the error range of the target level, it is determined as a failure of the first level sensor.

The present invention for achieving the above object is a first level sensor for outputting the measured value according to the washing water level, the second water level sensor which is installed in a position close to the target water level, and detects the washing water level and outputs a detection signal; And a control unit for controlling water supply or drainage using the washing water level, and the control unit when the washing water level measured by the first water level sensor and the washing water level detected by the second water level sensor when the water supply or drainage of the washing machine reaches the target water level. Shut off the water supply or drainage of the washing machine.

Here, when the measured value measured by the first level sensor exists within the error range of the target level and the detection signal is detected by the second level sensor, the controller determines that the washing level reaches the target level.

In addition, the second level sensor is preferably an electric field sensor that generates an electric field when the washing level reaches the target level.

As described above, according to the washing machine and the water level detecting method of the present invention, an electromagnetic field sensor is further installed at a position close to the target water level, so that the water level can be accurately detected even in the low water level section.

This creates the effect of implementing various washing machine algorithms by applying the low water level section.

1 is a perspective view showing the configuration of a washing machine according to an embodiment of the present invention, Figure 2 is a cross-sectional view showing the configuration of a washing machine according to an embodiment of the present invention.

1 and 2, the washing machine according to an embodiment of the present invention is for fresh water and is rotatable in the drum-shaped water tank 11 and the water tank 11 installed in the main body 10. Rotating drum 12 is installed to be included.

The water tank 11 is installed so as to incline a predetermined angle α with respect to the installation surface of the washing machine as a whole so that the front portion 11a on which the inlet 11b is formed is higher than the rear portion 11c, and the inside of the water tank 11 Rotating drum 12 is installed in the inclined shape so that the front portion 12a formed in the inlet 12b in the same form as the water tank 11 is higher than the rear portion 12c.

That is, the rotating drum 12 is installed such that the front portion 12a on which the inlet 12b is formed faces the front upper portion so that the center of rotation line “A” is inclined at an angle with respect to the installation surface of the washing machine. do. At this time, the rotating drum 12 is rotatably supported in the center of the rear of the tank 11, the rotary shaft 13 is coupled to the center of the rear portion 12c is in a state capable of rotating inside the tank (11).

In addition, a plurality of through holes 12d are formed around the rotating drum 12, and a plurality of lifters are formed on the inner surface of the rotating drum 12 to allow the laundry to rise and fall when the rotating drum 12 rotates. 14) is installed.

On the outside of the rear part 11c of the water tank 11, a motor 15 is installed as a driving device for rotating the rotating shaft 13 connected to the rotating drum 12 to perform washing, rinsing, and dehydration operations. In the lower side, a washing heater 16 for heating the washing water supplied into the water tank 11 is installed.

The motor 15 includes a stator 15a fixed to the rear portion 11c of the water tank 11, a rotor 15b disposed in a rotatable state outside the stator 15a, and a rotor 15b and a rotating shaft. It consists of the rotation board 15c which connects 13.

In addition, the front part of the main body 10 corresponds to the inlet 12b of the rotating drum 12 and the inlet 11b of the water tank 11 so that the laundry can be put into the inside of the rotating drum 12 or the laundry can be taken out therein. An inlet 17b opened at a position is formed, and a door 17 for opening and closing the inlet 17b is provided at the inlet 17b.

The first water level sensor 31 is installed above the main body 10. And a pressure hose 32 for transmitting the pressure of the wash water in the water tank 11 to the first water level sensor 31 is installed between the water tank 11 and the first water level sensor 31.

A detergent supply device 18 for supplying detergent and a water supply device 20 for supplying washing water are installed at an upper portion of the water tank 11, and the washing water in the water tank 11 is disposed at the lower portion of the water tank 11. To drain the water, a drain 19 including a drain pipe 19a, a drain valve 19b, and a drain pump 19c is provided.

In addition, the second water level sensor 33 is provided at a position close to the target water level on the outer wall of the water tank 11.

Detergent supply device 18 is divided into a plurality of spaces inside, it is installed on the front side of the main body 10 to facilitate the user to put detergent and rinsing agent in each space.

The water supply device 20 is a water supply installed in the cold and hot water supply pipes 21 and 22 to supply cold water and hot water, and to control the water supply of the cold and hot water supply pipes 21 and 22. The valves 23 and 24 are provided.

At this time, the cold water and hot water supply pipes 21 and 22 are connected to the detergent supply device 18 so that water supplied from the outside can be supplied toward the detergent supply device 18. In addition, a separate water supply pipe 25 is installed between the detergent supply device 18 and the water tank 11 so that water passing through the detergent supply device 18 can be supplied to the water tank 11, and at the outlet of the water supply pipe 25. The water supply nozzle 26 is installed. This allows the water supplied into the water tank 11 to pass through the detergent supply device 18 so that the detergent inside the detergent supply device 18 can be supplied to the water tank 11.

3 is a control block diagram of a washing machine according to an embodiment of the present invention. As shown in FIG. 3, the washing machine includes a signal input unit 110, a temperature sensing unit 120, a first water level sensor 31, and a first washing machine. 2 is configured to include a water level sensor 33, a controller 130, a drive unit 140 and the display unit 150.

The signal input unit 110 inputs the washing course selected by the user and operation information such as washing temperature, dehydration RPM, and rinsing addition to the control unit 130, and the temperature sensing unit 120 supplies the washing water supplied to the water tank 11. Detect the temperature of

The first water level sensor 31 detects the water level of the wash water supplied to the water tank 11, and detects the pressure due to the water level through the pressure hose 32 to output a measured value having a variable frequency.

Referring to the water level detection process of the first water level sensor 31 described above, when the wash water is supplied to the water tank 11 of the washing machine, the washing water is filled in the water tank 11. When the wash water fills the water tank 11, the wash water compresses the air in the pressure hose 32, and the air pressurizes the diaphragm (not shown). The diaphragm is a device that converts air pressure or hydraulic pressure into displacement, and is pressed when the pressure is high and returns to work when the pressure is low.

When the diaphragm operates, the connected ferrite core (not shown) moves. When the ferrite core moves, the magnetic field applied to the coil L causes a change, and the change in the magnetic field changes the inductance of the coil L. If the inductance changes, the resonance frequency of the LC oscillator circuit changes. The variable frequency becomes a measured value of the first water level sensor 31 and is input to the controller 130.

The second water level sensor 33 is installed at a position close to the target water level of the outer wall of the water tank 11 to detect the water level of the wash water supplied to the water tank 11. In this case, when there are a plurality of different target water levels according to the washing administration, a plurality of second water level sensors 33 are installed to correspond to the plurality of different water levels.

The second water level sensor 33 may be an electric field sensor, for example, wherein the electric field sensor includes a plurality of electrodes in which one electrode is charged and the other electrode is grounded. When approached, the washing water level is sensed using the principle of forming an electric field by providing a conductive path from one electrode to ground.

In more detail, when a plurality of electrodes are installed in the second water level sensor 33 and the washing water level reaches the target water level, an electric field is generated and the detection signal is transmitted to the controller 130.

The controller 130 is a microcomputer that controls the washing machine according to the driving information input from the signal input unit 110. The washing water level and the second water level sensor 33 measured by the first water level sensor 31 when water supply or drainage of the washing machine is performed. Determine whether the washing water level detected by the target water level reaches the target water level, when the washing water level reaches the target level, the water supply or drainage of the washing machine is terminated.

In more detail, the controller 130 may measure the washing water level when the measured value detected by the first water level sensor 31 exists within an error range of the target water level and a detection signal is detected by the second water level sensor 33. It is determined that the water level has been reached and the water supply or drainage of the washing machine is terminated.

On the other hand, the controller 130 is the first level sensor 31 or the second level sensor 33 by using the measured value measured by the first level sensor 31 and the detection signal detected by the second level sensor 33. Determine more of the failure.

In detail, if the measured value detected by the first water level sensor 31 exists within an error range of the target water level but the detection signal is not detected by the second water level sensor 33, the controller 130 may control the second water level sensor. It is determined that the failure of (33) and the control so that the failure message of the second water level sensor is output.

In addition, when the detection signal is detected by the second water level sensor 33, but the measurement value detected by the first water level sensor 31 does not exist within an error range of the target water level, the controller 130 does not detect the washing water level. The failure of the first water level sensor 31 is determined by the failure of the first water level sensor 31 and is controlled to be displayed on the display unit 150.

The driving unit 140 drives the motor 15, the washing heater 16, the drain valve 19b, the drain pump 19c, the water supply valves 23, 24, and the like according to the drive control signal of the controller 130.

The display unit 150 displays a current driving state. If the first level sensor 31 or the second level sensor 33 is determined to be a failure in the controller 130, the display unit 150 displays a failure message as predetermined screen display means. .

Hereinafter, a washing machine configured as described above and its operation and effect will be described.

Figure 4 is a control flow diagram for explaining the water level detection process of the washing machine according to an embodiment of the present invention, referring to Figure 4, put the laundry inside the rotating drum 12, the user washes the course and washing temperature, dehydration When driving information such as RPM and rinsing is selected, the driving information selected by the user is input 400 to the controller 130 through the input unit, and the target water level is set according to the input driving information (410).

Next, the controller 130 turns on the water supply valves 23 and 24 so that the washing water is supplied into the water tank 11 through the water supply pipes 21 and 22 (420).

When supplying water, the controller 130 determines whether the measured value measured by the first water level sensor 31 exists within an error range of the target water level (430). For example, if the frequency corresponding to the target water level is 130 Hz and the error range is ± 20 Hz, it is determined whether the frequency (measurement value) measured by the first water level sensor 31 exists within 110 Hz to 150 Hz. The first water level sensor 31 is usually made of a mechanical water level sensor, and since it is difficult to detect an accurate water level due to the characteristics of the mechanical water level sensor, it is determined whether the measured value measured by the mechanical water level sensor exists within an error range of the target water level. Is to determine whether it is close to the target level. Here, the error range is a value which is set in advance, it is preferable to be set differently according to the structure and characteristics of the washing machine.

If the measured value measured by the first water level sensor 31 exists within an error range of the target water level, the controller 130 determines whether a detection signal is detected by the second water level sensor 33 (440).

For example, if the target water level according to the overall washing administration is 50mm and 70mm, respectively, the second water level sensor 33 is installed close to 50mm and 70mm, respectively, and when the water level reaches 50mm, the second water level sensor 33 The electric field is generated and outputs the detection signal so that the detection signal can be input to the controller 130. In addition, when the washing water level reaches 70 mm for another washing administration, as described above, an electric field is generated in the second water level sensor 33 to output a detection signal.

When the detection signal is detected by the second water level sensor 33 in step 440, the controller 130 turns off the water supply valves 23 and 24 to terminate the water supply (450).

After the water supply operation is completed, the motor 15 operates under the control of the controller 130, and the rotating drum 12 rotates at a low speed to perform the remaining strokes (washing, rinsing, and dehydrating strokes) according to the selected washing course ( 460).

If the measured value measured by the first water level sensor 31 does not exist within an error range of the target water level in step 430, it is determined whether the detection signal is detected by the second water level sensor 33 (470). When the detection signal is detected at the control unit 130, the controller 130 determines that the first water level sensor 31 is broken and displays a failure message of the first water level sensor 31 (480). By displaying the failure of the first water level sensor 31 on the display unit 150 as described above is configured to guide the user of the failure of the water level sensor efficiently.

If the detection signal is not detected by the second water level sensor 33 in step 440, the controller 130 determines that the second water level sensor 33 is a failure and displays a failure message of the second water level sensor 33 (490). ).

On the other hand, when washing is finished, the controller 130 drives the driving unit 140 to open the drain valve 19b. Then, the drain valve 19b is opened and drainage is made. When the drainage is started, the controller 130 determines whether the washing water level measured by the first water level sensor 31 and the washing water level detected by the second water level sensor 33 reach the target water levels as in the case of water supply. When the water level reaches the target water level, the controller 130 determines that the drainage is completed and ends the drainage of the washing machine.

1 is a perspective view showing the configuration of a washing machine according to an embodiment of the present invention.

2 is a cross-sectional view showing the configuration of a washing machine according to an embodiment of the present invention.

3 is a control block diagram of a washing machine according to an embodiment of the present invention.

4 is a control flowchart illustrating a water level detection process of the washing machine according to an embodiment of the present invention.

* Description of symbols on the main parts of the drawings *

31 ... 1st level sensor 33 ... 2nd level sensor

130 control unit 140 driving unit

150 ... Display

Claims (9)

Determining whether the washing water level measured by the first water level sensor and the washing water level detected by the second water level sensor reach a target level when water is supplied or drained; And when the two washing water levels reach the target water level, terminating water supply or drainage of the washing machine. The method of claim 1, wherein the second water level sensor, It is installed in a position close to the target water level, And a plurality of different target water levels according to the washing administration, wherein a plurality of target water levels are installed to correspond to the target water levels. The method of claim 2, wherein the determining step, When the measured value measured by the first water level sensor is within the error range of the target water level, and the detection signal is detected by the second water level sensor, the washing machine level detection to determine that the washing water level has reached the target water level Way. The method of claim 1, wherein the determining step, The water level detection method of the washing machine further determines whether the first water level sensor or the second water level sensor is broken by using the measured value measured by the first water level sensor and the detection signal detected by the second water level sensor. The method of claim 4, wherein the determining step, And a measurement value measured by the first level sensor is within an error range of the target level, but when a detection signal is not detected by the second level sensor, determining that the second level sensor is a failure. The method of claim 4, wherein the determining step, When the detection signal is detected by the second level sensor, but the measured value measured by the first level sensor does not exist within the error range of the target level, the level detection method of the washing machine to determine that the first level sensor failure. A first level sensor for outputting a measured value according to the washing level; A second water level sensor installed at a position close to a target water level and sensing the washing water level to output a detection signal; It includes a control unit for controlling the water supply or drainage using the wash water level, And the controller is configured to terminate the water supply or drainage of the washing machine when the washing water level measured by the first water level sensor and the washing water level detected by the second water level sensor reach the target water level during water supply or drainage of the washing machine. The method of claim 7, wherein the control unit, The washing machine determines that the washing water level has reached the target water level when the measured value measured by the first water level sensor is within an error range of the target water level and a detection signal is detected by the second water level sensor. The method of claim 7, wherein the second level sensor, The washing machine is an electric field sensor that generates an electric field when the washing water level reaches the target water level.

Images