JPH0313916B2 - - Google Patents

Description

Detailed Description of the Invention "Field of Industrial Application" The present invention relates to a laundry determining device that automatically determines the amount and type of laundry, for example, in a fully automatic washing machine, it determines the appropriate amount of water to be supplied according to the amount of laundry, This is useful for automatically setting the appropriate water flow strength etc. according to the type of material.

"Prior Art" Laundry amount detection devices have been known in the past, and in one example, a washing motor is operated with the water supplied to the washing tub down to a predetermined low water level, and the steady value of the input current of the washing motor is measured. The amount of laundry is determined based on its size. Since the input current of the washing motor has a characteristic of increasing according to the amount of load, if the input current is large, it is determined that the amount of load, that is, the amount of laundry is large.

On the other hand, there is no known device that automatically detects the type of laundry.

``Object of the Invention'' The present invention provides a device that can detect the amount of laundry and the type of laundry from a different perspective than the conventional device described above.Instead of measuring the input current of the laundry motor, The present invention provides a device that measures changes in water level in a washing tub and determines the amount of laundry and the type of laundry based on the change.

"Structure of the Invention" The laundry determining device of the present invention intermittently performs agitation by repeatedly stirring and stopping the laundry in the washing tub of a washing machine while water is being supplied to a predetermined water level. An agitation control means, a water level change detection means for detecting a water level change due to agitation, and a judgment for calculating the degree and amplitude of a water level change from the output value of the water level change detection means and determining the amount and type of laundry based on the ratio. The present invention is characterized in that the agitation on time by the agitation control means is shorter than the agitation on time of intermittent agitation in a normal washing process.

"Function" As a result of intensive research, the inventors of the present invention found that
When the laundry was placed in the washing machine's washing tub, the water was supplied to a predetermined low water level, and the water level was measured while stirring and stopping was repeated intermittently to agitate the washing tub. It was found that the amount decreased depending on the amount and type of In other words, the greater the amount of laundry or the greater the thickness of the fabric, the greater the drop in the water level.

This is because the laundry does not completely absorb water when water is simply supplied, but when it is stirred, it becomes more hydrated, and the water level is estimated to drop by the amount of water absorbed. This is thought to be because the greater the thickness of the cloth, the greater the amount of water absorbed by stirring.

On the other hand, apart from the above-mentioned drop in water level, agitation produces a so-called pump effect, which is intermittent, causing small fluctuations in the water level up and down, but it is important to note that the amplitude of these fluctuations varies depending on the amount and type of laundry. I found it. In other words, the larger the amount of laundry or the higher the thread density of the laundry, the smaller the amplitude.

This is thought to be because the greater the amount of laundry or the greater the thread density of the laundry, the greater the resistance and the more the water level fluctuation is hindered.

Therefore, by measuring the drop in the water level and the amplitude of the fluctuation, it becomes possible to determine the amount and type of laundry.

By the way, intermittent stirring can be considered to be the so-called reversed water flow in the normal washing process, and in this case,
For example, the stirring motor should be rotated clockwise for 2 seconds - stopped for 0.6 seconds -
There are some that repeatedly drive like 2 seconds counterclockwise rotation - 0.6 seconds stop.

However, unlike in the washing process where there is a sufficient amount of water, the amount of water is often insufficient when making the above laundry judgment, so it is necessary to perform the following process: Rotate for 2 seconds - Stop for 0.6 seconds - Rotate counterclockwise for 2 seconds - Stop for 0.6 seconds. ” is repeated.
It may be harsh on laundry.

Therefore, the inventor of the present invention conducted further research and obtained data as shown in the graphs of FIGS. 6 and 7.

The graph shown in FIG. 6 shows the change in water level when 300 g of laundry is placed in a washing tub, water is supplied to a low water level, and stirring and stopping are repeated. The stirring direction is a constant direction. Here, d is the stirring on time of 0.5 seconds, e is 0.8 seconds, and f is 1.0 seconds or more.

The graph shown in Figure 7 assumes that the amount of laundry is 500g.
The case where the same stirring is performed is shown. d' is when the stirring on time is 0.5 seconds, e' is 0.8 seconds, and f' is 1.0 seconds or more.

FIG. 8 is a graph created from FIGS. 6 and 7, and shows the characteristics of the stirring on time and the change in amplitude.

As can be seen from the figure, the amplitude increases with time until the stirring on time is 1.0 seconds, but remains constant after 1.0 seconds. This is thought to be because the pump effect becomes saturated when stirring is on for 1.0 seconds or more.

What should be noted is that the difference between the curve g when the amount of laundry is 300g and the curve when the amount of laundry is 500g is larger when the agitation on time is between 0.5 seconds and 0.8 seconds than when it is 1.0 seconds or more. .

In other words, it is easier to detect the amount of laundry by setting the agitation on time to 0.5 seconds to 0.8 seconds rather than setting it to 1.0 seconds or more.

That is, the present invention was completed with attention to this point, and by shortening the agitation on time in intermittent agitation compared to the agitation on time in a normal washing process, it is possible to avoid harsh conditions on the laundry. This prevents agitation and also makes it easier to determine the amount and type of laundry.

"Example" The present invention will be described in more detail below based on the example shown in the drawings. Here, FIG. 1 is a schematic structural explanatory diagram of an example of a washing machine including an embodiment of the laundry determination device of the present invention, and FIG. 2 is a diagram illustrating the function of the laundry determination device in the washing machine shown in FIG. Figure 3 is a flowchart of the main parts of the part related to the function as a laundry determination device, Figure 4 is a characteristic diagram showing changes in agitation time and water level, and Figure 5 is a water level with respect to the amount of laundry. FIG. 3 is a diagram showing the relationship between the change amount and the ratio of the fluctuation amplitude. Note that the present invention is not limited to the embodiments shown in the figures.

A washing machine 1 shown in FIG. 1 basically includes a water supply valve 2, a water level sensor 3, a washing/dehydration tank 4, a water tank 5, a pulsator 6, a drive mechanism 7, a motor 8, and a control circuit 10. .

Here, other components except the control circuit 10 are:
It is similar to the corresponding components known in the art. The control circuit 10 is different from the conventional one in that it functions as a laundry determination device (in this embodiment, a device for determining the amount of laundry) 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 by the amplifier circuit 11 of the control circuit 10 as a water level signal d.

The water level signal d is sent to the microcomputer 13.
is input.

The microcomputer 13 reads the operator's instructions via the operation unit 14 . It also controls the water supply valve 2 and motor 8.

Next, with reference to FIG. 3, the laundry amount detection and water supply processing in the washing machine 1 will be described.

The operator puts the laundry Q into the washing and dehydrating tank 4,
When a water supply instruction is given from the operation unit 14, the microcomputer 13 enters the process shown in FIG. 3a.

First, the microcomputer 13
Open and start water supply (S1).

The water level signal d output from the amplifier circuit 11 is read, and water supply is continued until a predetermined low water level is detected (S2), and when the water level reaches a low level, the water supply valve 2 is turned off (S3).

Next, C/A value detection processing (S4) is performed. The C/A value detection process is a series of processes shown in FIG. 3b.

That is, in the C/A value detection process, the water level signal d is first read (S21). The value read thereby represents the low water level _L1 , and this value is stored in the memory (S21).

Next, a time width T _d (for example, 5 seconds) for measurement is set (S22).

Next, the time T ₀ (for example, 0.5
seconds) (S23), and drives the motor 8 for the set time _T0 (S24) (S26) (S27),
The water level during that time is read at predetermined short intervals (for example, 0.1 seconds) and stored (S25).

Next, the time T _f (for example, 1
seconds) (S27), and the motor is stopped for that time _Tf (S30). The water level during this time is read at predetermined short intervals and stored (S29).

The driving of the motor 8 for the time T ₀ and the stopping of the motor 8 for the time T _f are repeated and continued for the time T _d (S31).

This stirring is intermittent stirring, and the stirring direction may be reversed each time the stirring is interrupted, or may be in a constant direction. Here, the latter type of intermittent stirring is performed. This is because it is less harsh on the laundry Q if the direction is fixed.

When the motor 8 is driven and the pulsator 6 is rotated, the water also rotates, and the peripheral portion of the water in the washing and dewatering tank 4 is lifted up by centrifugal force. Such a state is indicated by H in FIG.

When the surrounding area of the water in the washing machine and dehydration tank 4 lifts up, the washing and dehydration tank 4
The water between the washing and dehydrating tank 4 and the water tank 5 is drawn into the washing/dehydrating tank 4, and the water level between the washing/dehydrating tank 4 and the water tank 5 is lowered as shown by h in FIG.

When the pulsator 6 stops, the raised water surface H returns to its original level, so that the lowered water surface H rises to its original height. Also, due to inertia, it becomes higher than the original water surface.

As a result, the water level detected by the water level sensor 3 is
With the continuous operation of the pulsator 6, small vertical fluctuations are repeated.

However, the laundry Q acts as a resistance to the pump effect, and the degree of this resistance increases as the amount of laundry increases, so the amplitude of the vertical fluctuation becomes smaller as the amount of laundry increases.

On the other hand, as a result of being stirred, even if the laundry Q initially appears to be floating on water, it is drawn into the water and becomes further hydrated. Therefore, the water level is lowered from the original water level by the amount of water contained in the laundry Q.
The magnitude of the decrease is proportional to the amount of water contained in the laundry Q, which in turn is proportional to the amount of laundry Q.

In this way, a water level change characteristic as shown in FIG. 4a is obtained.

Here, w is the case of only water, and although the water level fluctuates up and down due to the pump effect, the average water level remains at the low water level _L1 .

A is when the amount of laundry is small (for example, 500g), and along with the vertical fluctuation due to the pump effect,
There is a drop in water level due to water content. However, due to the resistance caused by the laundry Q, the pumping effect is slightly reduced, and the amplitude of the vertical fluctuation is smaller than w. In addition, since the laundry Q is small, it is almost completely submerged under the water surface and contains sufficient water, so the water level does not decrease much due to stirring, and the maximum value of the fluctuation is above the low water level L ₁ . It is in.

b is a case where the amount of laundry is medium (for example, 1 kg). The amplitude of the vertical fluctuation due to the pump effect is a
becomes smaller than . On the other hand, the water level has decreased significantly due to water content, as there are many parts that protrude above the water surface.

In c, when the amount of laundry is large (for example, 2 kg), the amplitude of the vertical fluctuation due to the pump effect is even smaller, while the drop in the water level due to water content is greater than in case b because there are many protruding parts above the water surface. It's summery.

Next, the maximum value J and minimum value K of the obtained data are obtained. These are the maximum and minimum values of the water level during the reading period (S32).

Next, according to the formula, the difference C between the maximum value J and the predetermined water level L
is calculated, and the amplitude A of the water level change is determined using the formula (S33).

C=|J-L|... A=J-K... Furthermore, the ratio C/A is calculated by the formula (S
34).

Ratio = C/A... As understood from the "low water level" curve l in Figure 5, the C/A value is a value that is almost proportional to the amount of laundry, so it should be used as a guideline for determining the amount of laundry. Can be done.

When the C/A value is obtained by the C/A value detection process, it is determined whether the C/A value is larger than a predetermined value (S5).

If the C/A value is smaller than ε, the amount of laundry is estimated to be small, and it is determined that the amount of water supplied is sufficient at a low water level. Water supply is completed there.

On the other hand, if the C/A value is equal to or larger than ε, the water supply valve 2 is turned on (S6), water is supplied until the middle water level is detected (S7), and the water supply valve 2 is turned off at the middle water level ( S8). That is, water supply is added up to the mid-water level.

When water is supplied to the middle water level, the C/A value detection process is performed again (S9).

This C/A value detection process is as described above with reference to FIG. 3b. However, the reference water level stored in the memory is the middle water level _L2 .

FIG. 4b shows the water level fluctuation at the middle water level. Here, w ₀ indicates the case where only water is used, b ₀ indicates the case where the amount of laundry is medium, and c ₀ indicates the case where the amount of laundry is large.

As can be understood from the curve m for "medium water level" in Figure 5, the C/A value will be a value smaller than ε when the amount of laundry Q is medium, and a value larger than ε when the amount of laundry Q is large. Become.

Thus, if the amount of laundry is medium and the C/A value is smaller than ε, water supply is completed up to the medium water level (S
10).

On the other hand, if the C/A value is equal to or larger than ε, it is considered that the amount of laundry is larger than the amount of water supplied, and more water is supplied. That is, the water supply valve 2 is turned on (S11).

However, since there is an upper limit to the amount of water that can be stored in the washing and dewatering tank 4, when water is supplied until a high water level is detected (S12), the water supply valve 2 is turned off (S1
3), Water supply is completed.

Note that, as shown in "High water level" in FIG. 5, at a high water level, the C/A value is smaller than ε even if the amount of laundry is large.

As can be understood from the above description, according to the washing machine 1, since the agitation ON time is short and the agitation is performed in a fixed direction, harshness on the laundry Q can be prevented. Furthermore, since the determination is made based on the ratio of the amount of change in water level to the amplitude, the amount of laundry can be detected with equal accuracy from a small amount to a large amount. Furthermore, even if there are variations in the water level sensor, etc., they are eliminated by taking the ratio, so high detection accuracy can be obtained. In this way, since the amount of laundry can be detected accurately, an appropriate amount of water can be supplied, and damage to the laundry and waste of water and power can be prevented.

As another example, instead of taking the maximum value as described above, the value L of the water level after stirring may take a minimum value of vertical fluctuations, or an intermediate value of vertical fluctuations.

In addition, as in the above example, there are two types of water levels: low water level and medium water level.
Instead of setting values in stages, one example is one in which water level settings are provided in one stage or three or more stages.

As yet another embodiment, in a washing machine in which the water supply valve 2 does not automatically open and close, the detected amount of laundry etc. is displayed by a display means such as a buzzer or LED, and
One example is one that generates a signal to start or stop water supply.

Further, as another example, the stirring on time
One example is one in which T ₀ is determined between 0.6 seconds and 0.8 seconds.

"Effects of the Invention" According to the present invention, the agitation control means intermittently performs agitation by repeating agitation and stopping in the washing tub with laundry placed in the washing tub of the washing machine and water being supplied to a predetermined water level. , a water level change detection means for detecting a water level change due to stirring, and a determination means for calculating the degree and amplitude of the water level change from the output value of the water level change detection means and determining the amount and type of laundry based on the ratio. In addition, there is provided a laundry determination device characterized in that the agitation on time by the agitation control means is shorter than the agitation on time of intermittent agitation in a normal washing process, and thereby the following effects can be obtained.

Since the agitation ON time is short, harshness on the laundry is prevented.

Detection sensitivity is increased because detection is performed before the amplitude of water level fluctuations reaches saturation.

Since the determination is made based on the ratio between the amount of change in water level and the amplitude, the amount of laundry can be detected with equal accuracy from a small amount to a large amount.

Even if there is variation in accuracy in the water level change detection means, the influence is eliminated by taking the ratio as described above, so high detection accuracy can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a schematic structural explanatory diagram of an example of a washing machine including an embodiment of the laundry determining device of the present invention, and FIG. 2 is a diagram illustrating a portion of the washing machine shown in FIG. Main part block diagram, Fig. 3 is a main part flowchart of the part related to the function as a laundry determination device, Fig. 4 is a characteristic diagram showing changes in stirring time and water level, and Fig. 5 shows changes in water level with respect to amount of laundry. FIG. 6 is a diagram of the amplitude of water level when the stirring on time is changed, FIG. 7 is a diagram of the amplitude of water level, and FIG. 8 is a diagram of the amplitude change characteristics. (Explanation of symbols) 1...Washing machine, 2...Water valve, 3
...Water level sensor, 4...Washing/dehydration tank, 5...Water tank, 6
...Pulsator, 8...Motor, 10...Control circuit.

Claims (1)

[Scope of Claims] 1. An agitation control means for intermittently stirring the washing tub of a washing machine by repeating agitation and stopping while the laundry is placed in the washing tub and water is supplied to a predetermined water level, and the water level caused by the agitation. comprising a water level change detection means for detecting a change and a determination means for calculating the degree and amplitude of the water level change from the output value of the water level change detection means and determining the amount and type of laundry based on the ratio,
A laundry determination device characterized in that a stirring-on time by the stirring control means is shorter than a stirring-on time of intermittent stirring in a normal washing process. 2 The stirring control means controls the stirring motor on time.
The laundry determining device according to claim 1, wherein the time is 0.5 seconds to 0.8 seconds. 3. The laundry determining device according to claim 1, wherein the stirring control means sets the stirring direction in a constant direction. 4. The laundry determination device according to any one of claims 1 to 3, wherein the water level change detection means includes a water level sensor using a semiconductor strain gauge type pressure sensor.