JPS628797A - Water feed state detector of washing machine - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a water supply state determining device for a washing machine, and more particularly to a device that determines the balance between the amount of laundry and the amount of water supplied.

``Prior Art'' In a washing machine, it is natural that the amount of laundry and the amount of water supplied should be balanced. If the amount of water supplied is too little, the laundry will be damaged and cannot be washed satisfactorily, and if it is too much, water, detergent, This results in a waste of electricity, etc.

Therefore, it is necessary to know the balance between the amount of laundry and the amount of water supplied, but there is no known hanging device that can detect such a balance.

Therefore, the amount of water supplied to conventional washing machines is currently determined appropriately based on the operator's experience.

By the way, there is a device called an automatic water supply device, and a typical example of such a device is to supply water to the washing tub to a predetermined low water level, operate the washing motor, and measure the steady value of the input current of the washing motor. 9. Depending on the size of the laundry, reduce the amount of laundry.
Water is classified into three levels: medium and high, and the amount of water supplied is determined so that the water level is low, medium, or high.

This is to estimate the washing fI4IAf from the load amount of the washing motor and determine the water supply amount accordingly.

``Problem to be solved by the invention'' When determining the amount of water to be supplied to the laundry based on the operator's experience, there is a problem that objective accuracy cannot be expected.

In addition, when using the conventional automatic water supply device described above, there is a problem that it is not always possible to accurately estimate the amount of laundry because the load on the washing motor varies depending on the type of laundry. .

SUMMARY OF THE INVENTION In order to solve these problems, the present invention aims to provide a device that can directly and accurately detect the balance between the amount of laundry and the amount of water supplied.

``Structure of the Invention'' The water supply state determination device for a washing machine of the present invention includes a water level increase rate detection means for detecting the increase rate of the water level in the washing tub of the washing machine, and a water level increase rate detected by the water level increase rate detection means. The present invention is characterized in that it is equipped with a water supply criticality determining means that determines that the water supply is critical when becomes a predetermined value, and outputs a criticality signal.

"Function" The inventors of the present invention studied how the water level increases when water is supplied at a constant rate to a washing tub filled with laundry, and they found a peculiar phenomenon as shown in Figure 4. It was discovered that the characteristics of

That is, in FIG. 4, a represents the water level increase characteristic when the amount of laundry is small. The reason why the water level is accompanied by a small amplitude is that a so-called water pump effect occurs due to intermittent stirring. Similarly, b
C represents a case where the amount of laundry is medium, and C represents a case where there is a large amount of laundry.

Moreover, S represents the case where water is simply supplied to the washing tub without stirring or adding laundry (referred to as simple water supply).

As can be understood from the water level change curves a, b, and c, the water level increase characteristic when laundry is loaded shows characteristics consisting of the following three regions, regardless of the amount of laundry.

■ In the initial stage of water supply, the increase in water level is slower than the increase in water level in the case of simple water supply, that is, the rate of increase is small.

■ Once water is supplied to a certain extent, the water level increases faster than the increase S in the case of simple water supply. In other words, the rate of increase is large.

■ Eventually, the water level will increase at the same rate as the increase S in the case of simple water supply. In other words, the rate of increase is the same as in the case of simple water supply.

The above characteristics are shown in the water level change curve a in FIG.

The curve a"B in Figure 5 is drawn by connecting the maximum values of b and e.
It will be more clearly understood with reference to I, c I.

Here, it is thought that in the above region (2), since the supplied water is absorbed by the laundry, the increase in water level appears less than in the case of simple water supply.

Next, in the region (■) above, the absorption of water into the laundry is saturated, and the supplied water appears as an increase in the water level, but the cross-sectional area of the washing tub is substantially reduced due to the presence of the laundry. Because of this, the water level is thought to rise faster than in the case of simple water supply.

In the area marked above, the amount of water is large compared to the amount of laundry,
The effect of reducing the cross-sectional area of the washing tub due to laundry is lost,
It is assumed that the water level will rise at the same rate as in the case of simple water supply.

Therefore, if we focus on when the rate of increase in the water level in the washing tub shifts from an area where it is greater than the rate of increase in the case of simple water supply to an area where it is equal to the rate of increase in the water level in the case of simple water supply, we can determine whether the laundry is submerged below the water surface or It is thought that the amount of water rises from the bottom of the washing tub, and this is considered to be the water supply critical point where the amount of laundry and the amount of water supplied are balanced.

Since this condition is directly determined by the amount of laundry, it is possible to accurately determine the balance between the amount of laundry and the amount of water supplied without being affected by the type of laundry.

In addition, for washing, it is necessary to continue supplying water until the water supply criticality is reached, but after that, the water supply may be stopped immediately after the water supply criticality is reached, or after a certain delay. This is because the proportion of water passed through washing varies depending on the type of cloth.

"Example" The present invention will be described in more detail below based on the example shown in the drawings. Here, FIG. 1 is an explanatory diagram of the configuration of a washing machine equipped with an embodiment of the water supply status determination device of the present invention, and FIG. Figure 3 is a flowchart showing water supply status determination and water supply control processing in the washing machine shown in Figure 1, Figure 4 is a water level change characteristic diagram, and Figure 5 is a diagram connecting the maximum values of the water level change characteristics shown in Figure 4. The drawn water level change characteristic diagram, No. 611J, is a characteristic diagram showing changes in the rate of increase in the water level change characteristic diagram shown in FIG. Note that the present invention is not limited to this example.

A washing machine 1 shown in FIG. 1 has a water supply valve 2. Water level sensor 3. Washing tub4. Water [5, pulsator 6, drive mechanism 7. motor 8
and a control circuit 10.

Here, other components except for the control circuit 10 are the same as corresponding conventionally known components. The control circuit 10 is different from the conventional one in that it functions as a water supply status determination device according to the present invention.

As shown in FIG. 2, the water level sensor 3 is, for example, a semiconductor strain gauge type pressure sensor, and changes its resistance value depending on the water level.

The change in resistance value is output as a water level signal d by the amplifier circuit 11 of the control circuit IO.

The water level signal d is input by the peak hold circuit 12 of the control circuit 10 to the microcomputer 13 as a peak hold value e.

The microcomputer 13 reads the operator's instructions via the operation unit 14. It also controls the water supply valve 2 and motor 8, reads the peak hold value e output by the peak hold circuit 12, and clears the peak hold circuit 12 for the next peak hold.

Next, with reference to FIG. 3, the water supply state determination and water supply control processing in the washing machine 1 will be described.

When the operator puts the laundry Q into the washing tub 4 and gives an instruction to supply water from the operation unit 14, the micro combinator 13
The process shown in FIG. 3 begins.

First, the microcomputer 13 opens the water supply valve 2 and
Start water supply (Sl).

Next, the time width T for calculating the rate of increase in water level.

(32).

Next, the peak hold circuit 12 is cleared to prepare for a new peak hold (S3).

Next, set the time T0 for turning on i-8 (S4),
Drive the motor 8 for the set time T0 54) (S6
)(37), set the time TI for turning off the motor 8.
8), the motor is stopped for that time T (S9).

The above time T. driving the motor 8 for a time T, and driving the motor 8 for a time T.
is repeatedly stopped for the above-mentioned time TJ (S 1
0).

When the time TJ has elapsed, since the peak hold circuit 12 holds the maximum value of the water level during that time, the peak hold value e is read (511).

Next, the difference ΔB between the read peak hold value e and the previously stored peak hold value e is calculated (S
12).

Once the difference ΔB, that is, the increase ΔB is calculated, the increase ΔB is divided by the time width T, l to calculate the increase rate ΔB/TJ (S13).

The change in the increase rate ΔB/T obtained here with respect to the water supply time T is as shown in FIG. In other words, simple water supply, small to medium amount of laundry.

Corresponding to large quantities, S″, a″ b //, respectively.
C'' indicates the change characteristic, but in the case of simple water supply, the increase rate ΔB
/ T a is constant. Small to medium amount of laundry.

In the case of a large amount, the rate of increase converges to the rate of increase in the case of simple water supply at a certain point, that is, beyond the water supply critical time.

Therefore, it is only necessary to compare the increase rate ΔB / T j with the preset increase rate in the case of simple water supply, but considering that there are variations, when the increase rate ΔB / T j is within the predetermined range 51 to S2, the increase rate ΔB /Ta is determined to be the increase rate of simple water supply (S14).

Also, since the transient increase rate ΔB/T when moving from the region (■) to the region (■) matches the increase rate in the case of simple water supply, in order to ignore this, nothing is done in the -th coincidence. Without doing so, it is determined that the water supply has become critical for the second time (S
15).

Instead of doing this, changes in the rate of increase ΔB/Ta may be checked, and when the rate of increase B/Ta decreases and matches the rate of increase of simple water supply, it may be determined that the water supply is critical.

If it is determined that the water supply is critical, the water supply valve 2 is turned off and the water supply is stopped (S16).

The water supply will be stopped due to the above, but the amount of water supplied at this time will be:
The laundry is just soaked in water, and there is just enough water for normal washing. However, as described above, more water may be supplied if desired.

As another example, instead of calculating the weight of the maximum value of the water level as described above, the rate of increase of the minimum value of the water level is calculated, or the rate of increase of the average value of the maximum value and the minimum value of the water level is calculated. Examples include those that do not perform intermittent stirring, and those that do not perform intermittent stirring.

In yet another embodiment, in a washing machine in which the water supply valve 2 does not automatically open and close, a buzzer, LED, or other display means indicates that the water supply has become critical, prompting the operator to stop the water supply. Things can be mentioned.

"Effects of the Invention" According to the present invention, the water level increase rate detection means detects the increase rate of the water level in the washing tub of a washing machine, and the increase rate of the water level detected by the water level increase rate detection means becomes a predetermined value. Provided is a water supply state determination device for a washing machine, which is characterized by comprising a water supply criticality determining means for determining water supply criticality when the water supply is critical and outputting a criticality signal, whereby the water supply amount is balanced with the amount of laundry. It becomes possible to objectively and accurately determine the amount of laundry without any steps and regardless of the type of laundry.

Therefore, no matter the amount of laundry, it is possible to use the optimum amount of water for mending, preventing damage to the laundry, and eliminating waste of water, electricity, etc.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram of the configuration of a washing machine equipped with an embodiment of the water supply status determination device of the present invention, FIG. 2 is a circuit diagram of a main part of the water supply control section of the washing machine shown in FIG. 1, and FIG. Fig. 1 is a flowchart showing water supply status determination and water supply control processing in a washing machine. The drawn water level change characteristic diagram, FIG. 6, is a characteristic diagram showing changes in the rate of increase in the water level change characteristic diagram shown in FIG. (Explanation of symbols) ■...Washing machine 2...Water supply valve 3...Water level sensor 4...Washing tub 8...Motor
lO...Control circuit 12...Peak hold circuit 13...Microcomputer S13...Increase rate calculation process SI4. S15... Water supply criticality determination processing.

Claims (1)

[Claims] 1. Water level increase rate detection means for detecting the rate of increase in the water level in the washing tub of a washing machine, and when the rate of increase in the water level detected by the water level increase rate detection means reaches a predetermined value. 1. A water supply state determination device for a washing machine, comprising a water supply criticality determination means for determining water supply criticality and outputting a criticality signal. 2. The water supply state determination device for a washing machine as set forth in claim 1, comprising intermittent stirring means for intermittently stirring the inside of the washing tub when the water level increase rate detection means is activated.