JPH036835B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION FIELD OF INDUSTRIAL APPLICATION The present invention relates to a washing machine that can control washing time by detecting the soiled state of liquid.

Conventional structure and its problems Traditionally, when washing a washing machine, a time switch is set based on the amount of clothes and how dirty the washing machine is, based on the experience and feeling of the user, and the machine runs for the set time. It was hot. This has the drawback of taking unnecessary time and damaging the fabric. Therefore, as a means for detecting the washing state of a washing machine, a means for detecting the dirtiness (turbidity) of the washing liquid may be considered. As a means for measuring turbidity, there is a means for measuring turbidity by measuring the light transmittance of a liquid using a light emitting element and a light receiving element. According to this means, it is possible to detect a change in the turbidity of the washing liquid during the washing process, and it is possible to detect the end of washing. However, detergents currently on the market include detergents that contain phosphorus (phosphorus-containing detergents) and detergents that do not contain phosphorus (phosphorus-free detergents). Phosphorus-free detergents include powdered soaps, liquid detergents, and other synthetic detergents, as well as many other detergents. When each detergent is dissolved in water, the turbidity of the detergent solution is different, and in particular, there is a large difference between detergents with phosphorus and detergents without phosphorus. Phosphorus-free detergents have high turbidity, while phosphorous detergents have low turbidity. Therefore, even if a phosphorus-free detergent can detect changes in the turbidity of the washing liquid during the washing process, if a detection element with the same sensitivity characteristics is used, the turbidity of only the detergent liquid is high with a phosphorus-containing detergent. It becomes difficult to detect turbidity changes during the process. Therefore, in order to keep the sensitivity characteristics constant, a method was devised in which when a detergent with high turbidity, such as a phosphorus-free detergent, is used, the amount of light emitted by the light emitting element is changed depending on the amount used. However, if you use more than the rated amount of phosphorus-free detergent and the clothes are extremely dirty, or if the turbidity of the washing liquid is so high that the sensitivity characteristics cannot be maintained at a constant level even if the light emitting output of the light emitting element is maximized. In such a case, it is judged that there is no change in turbidity, which has the drawback of shortening the washing time.

OBJECTS OF THE INVENTION It is an object of the present invention to provide a washing machine that eliminates the above-mentioned drawbacks and can perform laundry appropriate for extremely dirty clothes.

Structure of the Invention The present invention includes a light-emitting element and a light-receiving element facing each other and provided in a part of the dehydration tray, and a detection element that detects the end of washing based on a change in the turbidity of the washing liquid. In order to maintain constant sensitivity characteristics, the amount of light emitted is switched, and after the start of washing, the initial turbidity is detected after stirring for a certain period of time, and if it is impossible to maintain constant sensitivity characteristics, This washing machine is characterized by setting the washing time depending on the level of initial turbidity.

DESCRIPTION OF EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

In FIG. 1, 1 is the main body of the washing machine, 2 is an outer tub suspended and supported by a suspension 3, and 4 is an inner tub for washing clothes, which has a large number of holes 5 in the wall surface.
A pulsator 6 stirs the clothes in the inner tank 4. 7 is a mechanical case with a built-in brake and clutch mechanism, 8 is a motor that rotates forward and reverse during washing and rinsing, and 9 is a drain valve that is closed during washing, rinsing, and water supply. A drainage path 10 is formed between the drainage valve 9 and the bottom surface of the outer tank. 1
1 is a drain hose connected to the drain valve 9, 12
is a detector provided in the drainage path 10. 13
is a light emitting element provided in the detector 12, and 1
4 is a light receiving element. Light emitting element 13 and light receiving element 1
4 across the drainage route 12.

Next, the operation of this washing machine will be explained.

There are many types of detergents, and the turbidity of the washing liquid varies greatly between phosphorus-free detergents and other detergents.
The turbidity of phosphorus-free detergents at the rated concentration is 200 to 250 ppm, while other phosphorus detergents, for example, have a turbidity of 30 to 250 ppm.
40ppm (rated concentration). As described above, the turbidity of the washing liquid varies greatly depending on the detergent, and if the same detector characteristics are used to detect changes in the turbidity of the washing liquid, the detection accuracy will be different. Therefore, in order to obtain approximately the same detection characteristics for any detergent, the following steps were taken. FIG. 2 is an equivalent circuit of the detector 12, in which changes in the turbidity of the liquid are replaced by changes in the output voltage _Vput . The relationship between the output voltage and the turbidity of the liquid is shown in FIG. By changing the value of the resistor R in Figure 2, the detection characteristics can be changed to R ₁ , R ₂ .R ₆ , R ₄
The curve is almost parallel to the curve. As for the characteristics of the detector 12, it is desirable that the output voltage and the turbidity be in a proportional relationship, and in FIG. 3, the range from _V1 to _V3 , which is approximately in a proportional relationship, is used. and,
The detection characteristics are changed depending on the initial turbidity of the washing liquid. For example, in the case of a phosphorus-containing detergent with low turbidity, if the turbidity at the initial stage of washing is A, the characteristic that the turbidity has an output voltage in the range of V ₂ to V ₃ is R ₁ , so R ₁
In the case of a phosphorus-free detergent with high turbidity, if the turbidity at the beginning of washing is B (Figure 3),
Since the characteristic in which the output voltage falls within the range of _V2 to _V3 at this turbidity is _R3 , detection is performed using the characteristic of _R3 .
However, there is a limit to the current that can be passed through the light emitting element 13 by changing the resistance R. Therefore, if you use a large amount of phosphorus-free detergent and your clothes are heavily soiled,
The turbidity of the washing liquid at the beginning of washing is abnormally large.
Even if the resistance R is set to the minimum value allowed by the light emitting element 13 and the maximum current is applied, the output voltage V ₂ to V ₃ in FIG.
There may be cases where it is not possible to obtain characteristics within the range of . In such a case, as the washing progresses, the turbidity of the washing liquid increases and the output voltage is detected in the range of V ₁ or less. If V ₁ or less, V ₁ or more
Compared to the range below V ₃ , the voltage change in response to turbidity changes is small. For example, if a detection method is used that finishes washing when the voltage change falls below a certain value, then the washing time will exceed V ₁ or V ₃ . It will be shorter than if it were detected in a range less than

Therefore, in the case of this embodiment, if the initial turbidity of the washing liquid cannot be corrected to a characteristic in the range of V ₂ or more and less than V ₃ , the maximum current allowed to the light emitting element is applied.
For example, if it is the characteristic of R ₄ in Figure 3, the turbidity of the washing liquid at the beginning of washing is more than O ^V in terms of output voltage.
If it is less than a ^V , the turbidity of the liquid is high and the dirt is the biggest, so wash for the longest time, and if it is more than a ^V or more b ^V
If less than 80% of the maximum washing time, b ^V or more
If it is less than V ₂ ^V , the washing time is divided into several ranks such as 60% of the maximum time, and the washing time is set based on the turbidity at the initial stage of washing. In this way, even if an unnecessarily large amount of phosphorus-free detergent is used and the clothes are extremely dirty, the washing time will not be shortened.

Effects of the Invention As described above, according to the present invention, even if the detection characteristics of the detector cannot be corrected due to excessive use of phosphorus-free detergent or extremely large stains, the washing time can be reduced. sufficient cleaning performance can be obtained without shortening the time.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a washing machine according to an embodiment of the present invention, FIG. 2 is a circuit diagram of a detection element used in the washing machine, and FIG. 3 is a characteristic diagram showing the sensitivity of the detection element. 12...Detector, 13...Light emitting element.

Claims (1)

[Claims] 1. A light-emitting element and a light-receiving element are installed in a part of the dehydration tray, facing each other, and a detection element is installed to detect the end of washing based on a change in the turbidity of the washing liquid.
In order to maintain constant sensitivity characteristics as a detection element,
It is configured to switch the amount of light emitted, and after the start of washing, the initial turbidity is detected after stirring for a certain period of time, and if it is impossible to maintain a constant sensitivity characteristic, the washing time is set according to the size of the initial turbidity. washing machine.