JPH0219196A - Liquid splash preventing device for washing machine - Google Patents

Abstract

PURPOSE:To prevent the generation of liquid splash by controlling a driving means according to an atmospheric pressure change degree in an air trap. CONSTITUTION:The atmospheric pressure of an air trap 6 is transmitted to a pressure detecting part 7. First, the output frequency of the pressure detecting part 7 in an early time is stored into a reference pressure value storing part 9. A timing, by which a pressure in the air trap 6 is made approximately maximum in the cycle of the rotation and stop of a pulsator 3, is set beforehand by a timing signal generating part 10, and a pulse is generated in synchronizm with the timing. The frequency outputted from the pressure detecting part 7 when the pulse arrives and a reference frequency stored in the storing part 9 are inputted to a subtracting part 11, and the difference is calculated. The difference data are inputted to a mean arithmetic part 12, a mean value is calculated, whether to exceed the detected quantity of a liquid splash generation limit level or not is judged by a judging part 13, and when the value exceeds the quantity, the fact that the liquid splash exists is decided, and a control signal to weaken the drive of the pulsator 3 is sent from a drive control part 5 to a driving means 4.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a device for preventing liquid from scattering in a washing machine during washing or rinsing.

Conventional technology Traditionally, washing machines have been controlled by sensors that automatically set the water level and water flow based on the amount of laundry loaded.
A manual course has been implemented in which the user can freely select the water level, water flow strength, and washing time. Of these, the manual course did not provide any means or technology to automatically compensate for the inconveniences in washing methods.

Problems to be Solved by the Invention With such conventional technology, for example, when a user manually sets the water level to a high level and a single towel blanket causes extremely heavy swirling, water leaks during operation. Since it scatters outside the washing tub, there is a risk of corrosion of the floor and deterioration of the washing environment.

Therefore, in order to prevent this, it is customary to design the water flow to be weak in advance, and there is a problem that when the amount of cloth is large, it cannot be washed well.

The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide a device that has a simple configuration and prevents the occurrence of liquid scattering during washing or rinsing.

Means for Solving the Problems The liquid scattering prevention device for a washing machine of the present invention includes a drive means for rotationally driving a pulsator, a drive control section for controlling a drive time limit of this drive means, and an air filter provided at the bottom of an outer tub. A pressure detection part that detects the pressure inside the trap, a timing signal generation part that generates a pulse when the pressure inside the air trap reaches almost the maximum during the rotation and stop cycle of the pulsator during washing or rinsing, and the rotation drive by the pulsator. A reference pressure value storage unit stores the pressure value detected by the pressure detection unit at an appropriate time when the timing signal is not set as a reference value, and the difference between the pressure value obtained from the pressure detection unit in synchronization with the timing signal and the reference value. an average calculation unit that calculates the average value of the subtraction unit power at an appropriate number of cycles of rotation and stop of the pulsator; and an average calculation unit that calculates the average value of the subtraction unit power at an appropriate number of cycles of rotation and stop of the pulsator, and a judgment as to whether or not liquid has occurred in the tank based on the output of this average calculation unit. and a determination section for performing the determination.

Effect The present invention has the above-mentioned configuration, so that when there is a possibility of a lot of liquid scattering, the water pressure in the washing tub will fluctuate widely, and conversely, when stirring the type and amount of cloth with less liquid scattering, the water pressure will fluctuate widely. The fluctuation range is small. Taking advantage of this fact, in one cycle of rotation and stop of the pulsator during washing or rinsing, liquid scattering can be detected from the change in pressure when the pressure inside the air trap is almost at its maximum, especially in the one cycle in which such characteristics are particularly noticeable. It's about getting information.

EXAMPLE An example of the present invention will be described below with reference to the accompanying drawings. In Figure 1, 1 is the outer tub of the washing machine, 2 is the washing tub,
3 is a pulsator that generates a water flow in the washing tub 2; 4 is a drive unit that rotationally drives the pulsator 3; 5 is a drive control unit that controls the drive unit 4; and 6 is connected to the bottom of the outer tub 1 to adjust the water pressure to atmospheric pressure. 7 is a pressure detection unit that outputs a signal according to the atmospheric pressure, 8 is an air hose that transmits the air pressure of the air trap 6 to the pressure detection unit 7, and 9 is an appropriate air trap that is not rotated by the pulsator 3. Pressure detection section 7
10 is a timing signal that generates a pulse when the pressure inside the air trap reaches almost the maximum during the rotation and stop cycle of the pulsator 3 during washing or rinsing. Occurrence part, 11
12 is a subtraction unit that calculates the difference between the pressure value obtained from the pressure detection unit and a reference value in synchronization with the timing signal, and 12 is a subtraction unit that calculates the average value of the power at an appropriate number of cycles of rotation and stop of the pulsator 3. 13 is the average calculation unit 1
Based on the output of 2, determine whether there is a possibility of liquid scattering in the tank,
The output terminal 14 is a judgment unit connected to the input terminal 15 of the drive control unit 5, 16 is the washing clothes, 17 is the water surface A when the water flow is generated, and 18 is the state when the water flow is generated. This is the water surface B at the time of .

The pressure detection section 7 shown in FIG. 1 will be explained in detail based on FIG. 2. 20 is an airtight chamber maintained at the same pressure as the inside of the air trap 6 via an air hose 8; 21 is a flexible diaphragm; 22 is a ferrite core attached to the diaphragm 21; 23 is a constant on the diaphragm 21. 24 is a coil, 25 is a self-excited oscillation circuit, and 26 is an output terminal of the self-excited oscillation circuit 25, which is connected to both ends of the self-excited oscillation circuit 25. Both ends of the coil 24 are connected. This pressure detection unit 7 is mainly used to continuously detect the water level of the washing machine, and when there is no water in the washing tub 2, that is, the gauge pressure in the air trap 6 is O(mn+H20).
30 K from the output terminal 26 of the self-excited oscillation circuit 25 when
The constants of the circuit including the coil 24 are determined so that a square wave signal having an oscillation frequency of IIZ is output. Therefore, when water is supplied into the washing machine 2, the air pressure inside the airtight chamber 20 increases in proportion to the rise in the water level, and the diaphragm 21 is displaced outward by the pressure. Then, since the effective area of the core 22 attached to the diaphragm 21 with respect to the coil 24 increases, the coil 2
4 also increases, and the oscillation frequency of the self-excited oscillation circuit 25 decreases.

In this way, a continuous linear relationship is obtained between the water level, that is, the air pressure inside the air trap 6, and the frequency of the square wave signal output from the output terminal 26 of the self-excited oscillation circuit 25, as shown in FIG. This fact is used to obtain water level information from the output frequency. The above is a detailed explanation of the pressure detection section 7.

Next, the principle of detecting the possibility of liquid scattering will be explained with reference to FIG. The washing tub 2 has a hole on the side, and the lower part of the pulsator 3 on the bottom is connected to the inside of the outer tub 1, so water can freely flow therethrough. Therefore, when the pulsator 3 is not rotating, the water surface is the same for both the outer tub 1 and the washing tub 2. Next, during washing or rinsing, the drive means 4 drives the pulsator 3 in a rotation and stop pattern at regular intervals in response to a control signal from the drive control section 5. Then, a water flow following the pattern is generated in the washing tub 2. When the pulsator rotates, water is sucked from the outer tub 1 into the washing tub 2 due to its rotation, so the water pressure in the outer tub 1 decreases and the water level lowers.
On the other hand, in the washing tank 2, the water surface rises due to the inflow of water, and the peripheral part swells due to the centrifugal force of the water in the tank, and as time passes, the water surface becomes depressed in the center as shown in BI6. Become. In addition, when the pulsator is stopped, water gradually returns to the outer tank 1 through the hole on the side of the washing tub 2 and the lower part of the pulsator 3 immediately after the pulsator stops, so the water pressure returns to its original level and the water surface also returns to the water surface B. Shows movement back to position. In this way, it can be seen that the water pressure near the air trap 6 during a series of cycles of rotation and stop of these pulsators 3 shows a time change corresponding to the water flow. Then, naturally, the air pressure inside the air trap 6 shows a similar change, so the pressure detection section 7 can detect this change. Moreover, since the water flow intensity (the rise of the water surface in the peripheral area inside the washing tub 2) is proportional to the amount of water sucked in, it can be seen that it is also proportional to the time change in water pressure, that is, the time change in the air pressure inside the air trap 6. It is clear from our experiments that the stronger the fabric, the greater the amount of water splashed, and the greater the amount of reaction on the water surface after the pulsator 3 stops.Therefore, this reaction becomes almost the maximum. The principle of detecting liquid splashing is to obtain information on the occurrence of flying water from the pressure value at the time.Next, the present embodiment will be explained based on that principle.

First, the output frequency of the pressure detection section 7 at the initial stage when the pulsator 3 is not under rotation control is input to the reference pressure value storage section 9 and stored (.Continuing, one cycle of the pulsator 3 rotates for t1 seconds, rotates for t2 When the driving means 4 is controlled to stop for seconds, the output frequency of the pressure detection section 7 exhibits the characteristics shown in FIG. 4(a) with respect to time changes. Alternatively, the timing at which the pressure inside the air trap reaches almost the maximum during the cycle of rotation and stop of the pulsator during rinsing is set in advance.
Pulses are generated in synchronization with this timing. Fourth
In Figure (a), fO is the frequency output from the pressure detection unit 7 when the pulsator is not rotationally driven, the solid line is the waveform when there is little liquid scattering, and the - dotted chain line is the waveform when there is a lot of liquid scattering. So, fa.

fb is a frequency value output from the pressure detection unit 7 when the pressure inside the air trap reaches almost the maximum during the cycle of rotation and stop of the pulsator during washing or rinsing. In this way, dfl=fb-fO>df2=fa-
The relationship is fO, and it can be seen that the more liquid scatters, the greater the change. The frequency f output from the pressure detection unit 7 when the pulse of the timing signal comes and the reference frequency (reference pressure value) fO stored in the reference pressure value storage unit 9 are input to the subtraction unit 11. Then, the value of the difference df=f−fO between the frequency f and the reference frequency fO is calculated.

The calculated difference data between the frequency f for each cycle and the reference frequency fO is inputted to the continuous 20 cycle average calculating section 12, and the average value of the data of these 20 cycles is calculated. Then, the average value of the differences calculated by the average calculation unit 12 is input to the judgment unit 13, and it is determined whether the detected amount, which is the average value of the differences, exceeds the detected amount at the liquid scattering generation limit level. If it exceeds the limit, it is determined that there is a possibility of liquid scattering, and if it does not exceed the limit, it is determined that there is no possibility of liquid scattering. Furthermore, the output terminal 14 is connected to the input terminal 15 of the drive control unit 5, and if it is determined that there is a possibility of liquid scattering, a control signal is sent to weaken the drive (one cycle of the pulsator 3 rotates for tl-0, 4 seconds, 12 The drive controller 5 sends a control signal to the drive means 4, which causes the pulsator 3 to rotate for t11 seconds and stop for 12 seconds, which causes the pulsator 3 to rotate at a normal level when it is determined that there is no liquid scattering. . In this way, it is possible to perform control to weaken the drive when liquid scattering occurs, and it is possible to set a strong water flow that can sufficiently wash even when there is a large amount of cloth.

Effects of the Invention As described above, the present invention eliminates the possibility of liquid splashing by using a pressure detection device used to detect the water level of a washing machine and a control device such as a microcomputer without adding a particularly complicated device. The air pressure inside the air trap is used to detect changes in the water pressure level (especially when the pressure inside the air trap is almost at its maximum during the rotation and stop cycles of the pulsator during washing or rinsing). With a simple configuration that determines the presence or absence of liquid scattering based on the degree of pressure change and controls the drive means accordingly, it is possible to prevent liquid scattering, thereby reducing harmful effects such as floor corrosion and deterioration of the washing environment. It is extremely useful because it can remove the water, and as a result, the water flow can be designed to be strong, so even if there is a large amount of cloth, it can be washed well.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view showing an embodiment of the liquid scattering prevention device for a washing machine according to the present invention, FIG. 2 is a detailed cross-sectional view of the pressure detection section, and FIG.
The figure is a characteristic diagram of the pressure detecting section, and FIG. 4 is a diagram 11 showing the output of the pressure detecting section during one cycle of the rotation of the pulsator and the stop door during washing or rinsing. 1-11 outer tub of washing machine, 2-m-washing tub, 3-m-pulsator, 4-m=drive means, 5-m=drive control section, 6-
-Air trap, 7--Pressure detection section, 8-m-Air hose, 9-m=Reference pressure value storage section, 10-m-Timing signal generation section, 11-11 Subtraction section, 12-m-Average calculation section , Figure 1, Figure 1, Brother V Vise (Ga5qHtO) →

Claims (1)

[Claims] A drive means for rotating the pulsator, a drive control section for controlling the drive time of the drive means, a pressure detection section for detecting the pressure inside the air trap provided at the bottom of the outer tank, and rotation of the pulsator during washing or rinsing. and a timing signal generating section that generates a pulse when the pressure inside the air trap reaches almost the maximum during the cycle of stop and stop, and a timing signal generating section that generates a pulse when the pressure inside the air trap reaches almost the maximum, and a pressure value detected by the pressure detecting section at an appropriate time when the pulsator is not rotating. a reference pressure value storage unit that stores the reference value as a reference value; a subtraction unit that calculates the difference between the pressure value obtained from the pressure detection unit and the reference value in synchronization with the timing signal; It has an average calculation part that calculates the average value of the output of the subtraction part for an appropriate number of cycles, and a determination part that determines whether there is a possibility of liquid scattering in the tank based on the output of the average calculation part, and makes this determination. A liquid scattering prevention device for a washing machine that prevents liquid from scattering by appropriately changing a drive time limit of the drive control section according to an output of the section.