JP2782820B2 - Washing machine control device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control device for a washing machine in which a degree of contamination of a liquid in a tub is optically detected and a washing or rinsing operation is automatically performed. is there.

2. Description of the Related Art Conventionally, as a control device for this type of washing machine, Japanese Patent Publication No. Sho 61-50
There is one disclosed in Japanese Patent Publication No. 595. That is, a control device for a washing machine has been proposed in which a dirt degree detector for optically detecting a change in turbidity of the washing liquid is provided, and a washing or rinsing operation is automatically performed based on output data of the dirt degree detector. .

In the control device of the washing machine, a light-emitting element and a light-receiving element are provided at the inner bottom of the water receiving tank so as to face each other via the internal water, and an amount of output depending on the amount of light emitted from the light-emitting element is generated. The light-receiving element constitutes a dirt degree detector, and the washing time is determined by dividing the dirt on the laundry into "large", "medium", and "small" according to the change in the transparency of the washing water with respect to the fresh water being stirred. .

Problems to be Solved by the Invention However, in the control device of the washing machine as described above, the detergent which has fallen off from the laundry and the
When the surfaces of the light emitting element and the light receiving element are stained with water stains or the like, the output of the light receiving element is lower than when the surface is not dirty. That is, even if the laundry is not soiled, if the surfaces of the light emitting element and the light receiving element are soiled, the transparency of the washing water with respect to the fresh water becomes low, so that it is determined that the washing is large and the washing time is prolonged. Was.

Therefore, the present invention solves the above-mentioned conventional problems, and dirt adheres to the surfaces of the light-emitting element and the light-receiving element, and dirt is present in a light path between the light-emitting element and the light-receiving element, for example, a water receiving tank or a drain pipe. It is an object of the present invention to accurately detect a change in turbidity of a washing liquid due to dirt falling from laundry, and control a washing or rinsing operation even if it adheres.

Means for Solving the Problems To achieve the above object, a control device for a washing machine according to the present invention includes a water supply valve for supplying tap water into the tub, and a drain valve for draining the liquid in the tub. A light-emitting element and a light-receiving element provided near the drain valve to detect the light transmittance of the liquid in the tank, and a transmittance detector that detects the liquid transmittance using the light-emitting element and the light-receiving element. A water level detection means for detecting a water level in the tank, and a control means for receiving an output signal from the transmittance detector and the water level detection means and controlling the operation of the water supply valve and the drain valve, The means is configured to determine the drive current of the light emitting element after turning on the drain valve for a predetermined time when the water level detection means detects a predetermined water level during the water supply of the rinsing operation.

According to the present invention, since the drive current of the light emitting element is determined during the water supply of the rinsing operation, if a large amount of current is applied to the light emitting element even if dirt is attached to the inner wall in the vicinity of the drain valve, it is not dirty. A similar output is obtained.

Embodiment Hereinafter, an embodiment in which the present invention is applied to a fully automatic washing machine will be described with reference to the drawings.

FIG. 1 is a sectional view of a fully automatic washing machine.
Is a water receiving tank, 3 is a washing and dewatering tub, 6 is a power for switching the power of the washing and dewatering motor 5 so as to rotate the stirring blade 4 during washing or rinsing, and rotate the washing and dewatering tub 3 during dewatering. It is a switching mechanism. Reference numeral 7 denotes an air reservoir for generating a pressure corresponding to the water level, 9 denotes an air hose for transmitting the pressure generated in the air reservoir 7 to the water level detecting means 8, and 10 denotes the liquid in the water receiving tank 2. , A drain hose, and 12 a feed valve for supplying tap water into the water receiving tank 2. Reference numeral 13 denotes a transmittance detecting unit for detecting the transmittance of the liquid in the water receiving tank 2, and is composed of an infrared light emitting element 13a and a light receiving element 13b as shown in FIG.

Next, FIG. 3 shows a main configuration of the fully automatic washing machine. In the figure, reference numeral 14 denotes an input means for setting which step of washing, rinsing, and dehydration is to be operated, a water level, and the like, and 15 informs a user of the contents set by the input means 14 and the progress of washing. Is a water level detecting means for detecting the water level in the water receiving tank 2 and generating an electric signal, 16 and 17 are bidirectional thyristors for driving the washing and spinning motor 5, and 18 is a water supply valve. A bidirectional thyristor for driving 12; a bidirectional thyristor 19 for driving the drain valve 10; a commercial power supply 20; a power switch 21;
Is a transmittance detector for detecting the degree of contamination of the liquid in the inside, 23 is a peak hold circuit for finding the maximum value of the output signal of the transmittance detector 22 within a predetermined time, and 24 is a peak hold circuit 23 The output signal is input to the A / D converter and A / D converted.
A microcomputer (hereinafter, referred to as a microcomputer) is a control means for controlling the operations of the washing, rinsing, and dehydrating steps based on the data. Reference numeral 25 denotes a non-volatile memory. FIG. 4 shows the transmittance detector 22 and the peak hold circuit.
An example of 23 is shown. 22a includes a PWM circuit and a D / A converter, and receives a signal from the microcomputer 24 to receive an infrared light emitting element 13a.
22b and 22d
Is a resistor, and 22c is a transistor for controlling ON / OFF of a current flowing to the infrared light emitting element 13a based on a signal from the microcomputer 24. The peak hold circuit 23 includes transistors 23a and 23d, an electrolytic capacitor 23b, and a resistor 23c. One measurement will be described with reference to FIG. The microcomputer 24 turns on the transistor 22c only for _a period of _Tb (for example, 1 second) and _Ta (for example, 0.01 second) to supply a current to the infrared light emitting element 13a. At that time, the transistor 23 is selected according to the transmittance of the transmittance detection unit 13.
the base potential V ₁ of the a is changed as shown in FIG. 5.
In order to detect the maximum value between the predetermined time T _c of the voltage value of each the T _b (for example, 10 seconds), and input to the A / D converter of the microcomputer 24 via a peak hold circuit 23, following T _c the output voltage V _O of the transistor 23d to turn oN the peak hold circuit 23 to detect a maximum value between just prior to the OV, measuring the V _O converts a / D. Thus, (n is a natural number) n U between the predetermined time T _c by taking the maximum value of the values of V ₁ of the, it is possible to remove the influence of the bubbles generated in the wash.

Next, the washing control according to one embodiment of the present invention will be described with reference to FIGS. First, FIG. 6 is a graph showing a change in the output voltage V _O from the start of washing. Curve A in FIG. 6 indicates that the degree of dirt on the laundry is small, FIG. C is a case where the degree of dirt is large. here,
Paying attention to the saturation time t _s and the output voltage V _s at the time of saturation, the time until the output voltage V _O stops changing (for example, the time until the amount of change for 2 minutes becomes less than 0.1 V twice) is considered. , Sixth
As shown in the figure, in general, when the soil of the laundry is large (curve C), the saturation time is long at t _sc and the output voltage at the time of saturation is low at V _sc , and conversely, the laundry is dirty. when is small (curve a) is shorter saturation time in t _sa, the output voltage at saturation is V _sa
It becomes high with. Next, the flow of the washing control will be described with reference to FIG. The microcomputer 24 first from non揮撥volatile memory 25 in step 100, reads the PWM data for determining the drive current I _f of the light emitting element 13a, the transmission rate detection unit 13 the output voltage V _w at the time of Shimizu, step 101 Outputs PWM data with light emitting element 13
a so that a constant current _If flows through a.
12 is turned on to supply water to a predetermined water level, and in step 103, the stirring blade 4 is rotated to start a washing operation. If the change of the output voltage V _O for two minutes in step 104 becomes 0.1 V or less for two consecutive times, it is regarded as saturation. And the time from the washing operation starts until saturated with saturation time t _s at step 105, the output voltage at saturation as V _s, wash determines the time based on the value of t _s and V _s / V _w. Here are we the ratio of V _s and V _w is simply when determining the turbidity of only the washing liquid The value of the output voltage V _s of at saturation,
If the inner wall of the drain pipe in the transmittance detecting unit 13 becomes dirty with dirt that has fallen from the laundry or detergent or water residue that has not been dissolved during the laundry, the output voltage V _O will always decrease and the laundry will become dirty. Is determined to be large, and the washing time becomes longer. Therefore, in order to determine at all times the correct wash solution turbidity of, is not a ratio of the output voltage V _s of at saturation with respect to the output voltage V _w of fresh water.

Next, how to determine the output voltage V _w of the fresh water will be described with reference to Figure 8 and Figure 9. In the series of washing, rinsing, and dehydrating steps, the inside of the transmittance detecting unit 13 can become fresh water during the three times of water supply, ie, first washing, rinsing, and second rinsing, as shown in FIG. is there. However, during the washing water supply, if the user puts the detergent before starting the washing and then starts the washing, a strong liquid of the detergent flows into the transmittance detecting unit 13 at the first washing water supply, and the light transmittance is increased. drops, also lowered output voltage V _1. On the other hand, during rinse water supply, the transmittance detector
The inside of 13 is fresh water, but the softener is often put in the second rinse water supply, and the liquid is slightly turbid. Therefore, first transmission rate detection unit 13 in the feed water rinsing becomes Shimizu, it will be described with reference to a flowchart of FIG. 9 how to determine the output voltage V _w. Microcomputer 24 starts with step 150
Turn on the water supply valve 12 to supply water to the minimum water level, and
In step 1, the drain valve 10 is turned on for 3 seconds to drain. This is because the previous step is dehydration, and bubbles generated during dehydration are discharged from the transmittance detector 13. Next, at step 152, the output voltage V
The PWM data for determining the drive current I _f of suitable light-emitting element 13a so _{that 1} is always changing in the active region, the transmittance detecting unit 13 sets the time of Shimizu, the output voltages V ₁ at that time V _w And Then, in step 153, the data thus determined is written to the non-volatile memory 25 for use in the next washing. Subsequently, after water is supplied to a predetermined water level in step 154, rinsing control is entered in step 155.

According to the present invention as described above the effect of the invention, once the waste water to determine the driving current of the light emitting element from the sensor output voltage at that time and the output voltage V _w of the fresh water in the first rinse water so previous foam transmittance detector during dewatering stroke is all discharged a large amount even I savings, there is an effect that the output voltage V _w at the time when high accuracy Shimizu is obtained. As a result, in washing control,
When the sensor output voltage is saturated, the degree of turbidity of the washing liquid with respect to fresh water can be accurately detected, and an appropriate washing operation according to the degree of soiling of the laundry can be performed. Further, since the stored non揮撥volatile memory every time to determine the output voltage V _w at the time when the drive current and Shimizu of the light emitting element, for example, does not also adversely affect the next washing unplugged from the electrical outlet. Furthermore, since the drive current of the light emitting element is always determined once per washing, even if the inner wall of the transmittance detecting section is stained with water residue or undissolved detergent, a large amount of current is applied according to the stain. Thereby, there is an effect that the degree of soiling of the laundry can be accurately detected.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a fully automatic washing machine according to one embodiment of the present invention, FIG. 2 is a cross-sectional view of a transmittance detector of one embodiment of the present invention, and FIG.
FIG. 4 is a block diagram of a main part of a fully automatic washing machine according to an embodiment of the present invention, FIG. 4 is a circuit diagram of a transmittance detector and a peak hold circuit according to an embodiment of the present invention, and FIG. FIG. 6 is a timing chart of one embodiment of the present invention at the time of washing, FIG. 7 is a flowchart showing the operation of one embodiment of the present invention at the time of washing, and FIG. FIG. 9 is a flow chart showing the operation at the time of rinsing in one embodiment of the present invention. 2 ... water receiving tank, 10 ... drain valve, 13 ... transmittance detector,
13a: light emitting element, 13b: light receiving element, 19: drain valve driving means, 22: transmittance detector, 24: microcomputer.

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-60-135092 (JP, A) JP-A-62-295693 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) D06F 33/02 D06F 41/00

Claims (1)

(57) [Claims] A water supply valve for supplying tap water into the tank;
A drain valve for draining the liquid in the tank, a light emitting element and a light receiving element provided near the drain valve for detecting the light transmittance of the liquid in the tank, and using the light emitting element and the light receiving element A transmittance detector for detecting the transmittance of the liquid, a water level detecting means for detecting the water level in the tank, and an output signal from the transmittance detector and the water level detecting means, and the water supply valve and the drain valve Control means for controlling the operation of the, the control means, during the water supply of the rinsing operation, when the water level detection means detects a predetermined water level, after turning on the drain valve for a predetermined time, the light emitting element A control device for a washing machine that determines a drive current.