JPH03182296A - Control device for washing machine - Google Patents

Abstract

PURPOSE:To detect the absolute quantity of dirt and control washing and rinsing by adjusting the sensitivity of an optical sensor during the water feeding before rinsing stirring or during the water feeding before supplying a detergent. CONSTITUTION:An optical sensor 23 is formed of an light emitting element 230a and a light receiving element 230b. lt is formed of a flat member so that the passage of a light passing from the light emitting element 230a to the light receiving element 230b forms a parallel line, the sensitivity of a permeation detecting device is adjusted during water feeding before rinsing stirring or during water feeding before supplying a detergent, the light emitting output is adjusted and fixed at the time of clean water, and the light emitting output control data is stored, the light emitting output is fixed by the stored data at the time of the following washing to detect the change ratio of the light receiving element, whereby the absolute quantity of dirt can be detected. Namely, the logarithmic value of change ratio of the light receiving element output voltage at the time of clean water to the light receiving element output voltage at the time of washing or rinsing is proportional to the light absorption of washing water, so that the absolute quantity of dire can be detected. Hence, the optimum washing time can be inferred.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a washing machine control device that controls washing, rinsing, etc. operations depending on the degree of dirt in the washing liquid.

2. Description of the Related Art An example of a conventional method of controlling washing or rinsing operations by installing an optical transmittance detection device near the drain outlet of a washing tub is disclosed in Japanese Patent Publication No. 63-16157. In either case, the washing or rinsing operation is controlled by detecting changes in turbidity or permeability of the washing liquid during the washing or rinsing operation.

Problems to be Solved by the Invention However, the conventional transmittance detection method memorizes the transmittance at the initial stage of washing or rinsing and detects stains based on changes from the initial value, which has the following problems.

0) The initial permeability data during the washing operation varies greatly and is unstable due to the influence of the detergent, making it difficult to detect dirt due to changes in dirt during washing.

The transmittance detection level changes due to dirt inside the drainage pipe, etc. where the light-emitting element and light-receiving element are installed. That is, even if the dirt (permeability) of the washing liquid is the same, the change in permeability varies depending on the adhesion of dirt in the drain pipe, making it impossible to accurately detect the change in permeability.

As described above, in the past, since the absolute amount of dirt could not be detected, optimal control of washing time, etc. could not be performed.

In view of the above problems, an object of the present invention is to control washing, rinsing, etc. by detecting the absolute amount of dirt.

Means for Solving the Problems In order to achieve the above objectives, the present invention consists of a flat member so that the path of light passing from the light emitting element to the light receiving element is as parallel as possible, and the supply water before rinsing and stirring is Alternatively, the sensitivity of the permeability detection device is adjusted during water supply before detergent is added, and the absolute amount of dirt is detected based on the change in permeability from clean water.

The absolute amount of dirt can be determined by adjusting and fixing the water charging output when using fresh water, storing the light emitting output control data, fixing the light emitting output using the stored data the next time you wash, and detecting the rate of change of the light receiving element. Can be detected.

Function: The logarithm of the rate of change of the output voltage of the light receiving element during fresh water and the output voltage of the light receiving element during washing or rinsing is proportional to the absorbance of the washing liquid, making it possible to detect the absolute amount of dirt. By sensing the absolute amount of dirt, the optimal washing time can be deduced. In particular, when the amount of light emitted from the light emitting element is constant, the path of light from one light emitting element to the light receiving element housing is affected only by the absorbance of the washing liquid, and the light reception by the light receiving element is affected by changes in the refractive index due to changes in the concentration of the washing liquid. This eliminates the problem of a decrease in the amount of dirt, and it is possible to detect changes in absorbance, that is, the amount of dirt.

Example Hereinafter, the present invention will be described in detail with reference to the drawings.

FIG. 1 shows an embodiment of a control device according to the invention. 1 is an AC power source that applies AC power to the control device 2. Control unit @2
are the washing motor 3, its phase advancing capacitor 4, and the water supply valve 6.
The drain valve 6 is controlled to control washing or rinsing operation. A signal control circuit 20 is composed of a microcomputer and its peripheral circuits. Reference numeral 21 denotes an operation control circuit which is constructed like a key manual device consisting of a display device and a switch.

A switching circuit 22 is a power control switching device such as a thyristor that controls power components such as a washing motor. 2
Reference numeral 3 denotes an optical sensor composed of a light emitting element and a light receiving element.

24 is a water level sensor that detects the water level of the washing tub, and 25 is a cloth amount detection circuit that drives the washing motor 3 and counts the number of attenuated pulses of the phase advance capacitor 4 due to inertial rotation when the motor is turned off to determine the nemesis. .

FIG. 2 shows an example of a specific control circuit for the optical sensor 23. As shown in FIG. 230a is a light emitting element, 230b is a light receiving element, which are arranged to face each other, and 231a and 231b are respective protection diodes. 26 is a microcomputer having a pulse width control output terminal (PWM terminal for short) and an A/D conversion input terminal.

27 is a D/A conversion circuit, which is a CR integration circuit that converts the PWM signal into an analog voltage. 28 is a light emission output control transistor, and 29 is its emitter resistor which has a constant current function. A light emitting element 230 which controls the pace voltage of the transistor 28 by a PWM signal and is connected in series to the collector.
Control the light emission output of a. The output terminal of the light receiving element 230b is connected to the load resistor 3o, and its output voltage V. is connected to the A/D conversion input terminal of the microcomputer 26.

Reference numeral 31 is a storage means that stores PWM data for fully controlling one light emission output.

Figure 3 shows the optical sensor output voltage V when the button is pressed during washing and rinsing operation.
. shows the change in Optical sensor output voltage V during water supply before rinsing and stirring. The light emitting element 230 is set so that fiiv0 becomes the reference fiiv0.
The light emission output of a is adjusted by a PWM signal, and when the adjustment is completed, the PWM control data is stored and the light emission output is fixed at a constant value of 1 at the next adjustment. Output voltage change V during washing.

/v0 is proportional to the change in absorbance, that is, the amount of dirt.

Therefore, the saturation voltage v1 and saturation time Ts of the optical sensor output voltage
The amount and type of soiling can be determined and the optimal washing time can be deduced.

Figure 4 shows the relationship between dirt (absorbance) and sensor voltage change v1/v0, based on the Lampert-Beer law.The voltage of fresh water is V, assuming the light emission output is constant. and the sensor output voltage v of the liquid with unknown absorbance is v 1/V0=eXp
(-1-1k). e is the distance between the light emitting element and the light receiving element, and Jk is the change in absorbance from clean water, which is considered to be the amount of dirt. Also, from this formula, it can be seen that dirt inside the drain pipe is canceled. In other words, if the rate of change in sensor voltage with respect to change in absorbance is always logarithmic, dirt on the drain pipe can be made irrelevant. When the washing and draining pipes are not dirty and the washing liquid is dirty at A, the sensor voltage change rate is A'. If the drain pipe becomes dirty by the amount A, and the same amount of the washing liquid becomes dirty, it becomes the stain B. The sensor voltage change rate at this time is B
If it is a logarithmic change such as / /A /, it will have the same value as A'.

As described above, fr3 error (absorbance) and sensor voltage change can be determined.

FIG. 5 shows a mounting arrangement for an optical sensor according to the present invention. 32
is attached to the bottom of the washing tub with a drain pipe. 33 is a connection port connected to a water supply valve and a hose, and transparent water is supplied from the water supply valve.

230a is a light emitting element, 231a is a protection diode, and 232a is a mounting case. 233a is a transparent window made of flat and transparent resin.

234a is a printed circuit board to which the light emitting element 233a and the protection diode 231a are soldered. 236a is a moisture-proof resin that prevents corrosion of electronic components and printed circuit boards and prevents changes in permeability due to water intrusion.

23saFi printed circuit board 234a mounting case 232
This is the mounting screw for a. The light sensor transmitting portion of the drain pipe 24 and the transmitting window 233a are made of 4M, such as a flat and uniformly transparent transparent resin, so that the light from the light emitting element is not refracted. As shown in FIG. 8, light emitting elements 2 are provided facing each other.
If a lens such as 233a' or 233b' is provided in the transmitting part of 30a and the light receiving element 230b, the refractive index changes depending on the liquid concentration, and the rate of change in the output voltage of the light receiving element increases, but the rate of change in sensor voltage with respect to dirt is logarithmic. When the drain pipe becomes dirty, the rate of change in sensor voltage with respect to dirt (absorbance) decreases, causing a problem in that the detected value of the amount of dirt changes.

FIG. 6 shows an embodiment of a flowchart of stain detection and washing control according to the present invention. Reference numeral 201 reads light emission output control data from the memory and controls the light emission output to be constant. Reference numeral 202 is a cloth amount detection subroutine, in which a very small amount of water is supplied from a water level casing, the stirring blade is rotated, the amount of cloth is determined based on the magnitude of a capacitor pulse caused by inertial rotation, and the water level is set according to the amount of cloth.

Washing and agitation is started at 203, and sensor signals are periodically input. 204 checks the saturation of the sensor voltage, and if it is saturated, executes the dirt detection and washing control flow of 206 and below. 2
06 calculates the saturation time T3, 207 calculates the voltage change rate at saturation, 20B calculates the additional washing time TF from the saturation time Ts and the voltage change rate, and 209 and 210 calculate the washing time T.
End detection is performed by inferring w=T B +T y. 211 is a rinsing step.

FIG. 7 shows an embodiment of a flowchart of the rinsing process. 213 determines the rinse setting water level, and if the water level is low, 2
Open the water supply valve at 14. 216 drains water for a certain period of time to remove dirt and bubbles from inside the drain pipe, and at the same time makes it easier for fresh water sent directly from the water supply valve to enter the drain pipe. 216 determines whether the light emission output adjustment water level has been reached; if Y, 2
At step 17, it is determined whether the sensor output voltage has reached the reference setting value. If it is N, the light emission output is adjusted, and if it is Y, the light emission output control data is stored in the storage means.

When the rinse water level reaches the set value, the water supply valve is turned off and the 220
The rinsing agitation is started at 221, and the rinsing agitation 1 is started at 221.
Input the sensor data after 5 minutes and check the difference voltage JV from the reference value.
Set the rinsing time 9 times, etc.

As mentioned above, FIG. 8 shows the transmission windows 233a' and 233b'.
This is the case when a lens effect is added to the image.

Effects of the Invention As described above, the present invention uses straight light without refraction so that the relationship between the contamination of the optical sensor and the sensor voltage change rate is logarithmic, and the change from the sensor voltage of fresh water before rinsing and agitation is Since it detects the amount of dirt, there is no change in the refractive index due to changes in the concentration of the washing liquid, and the relationship between sensor voltage changes (transmittance) from fresh water and dirt (absorbance) is logarithmic, and the light transmitted by the optical sensor is The dirt in the drain pipe passing through is canceled out, and the amount of dirt can be detected from the voltage change from the fresh water. The optimum washing time can be inferred from the permeability (v1/vo) corresponding to the amount of dirt and the degree of change in the permeability, and the lack of washing time, which is a drawback of conventional saturation detection, can be eliminated.

[Brief explanation of drawings]

Fig. 1 is a block diagram showing an embodiment of the control device according to the present invention, Fig. 2 is a circuit diagram showing an embodiment of the optical sensor and the light emission output control circuit, and Fig. 3 is the optical sensor during washing and rinsing operations. FIG. 4 is a diagram showing the relationship between contamination (absorbance) of the optical sensor and transmittance; FIG. 6 is a cross-sectional view showing an example of the configuration of the optical sensor; FIG. 6 is a diagram showing the structure of the optical sensor. FIG. 7 is a flowchart of a rinsing operation according to the present invention, and FIG. 8 is a sectional view showing an embodiment in which the transmission window of the optical sensor has a lens effect. 23... Optical sensor, 20... Signal control circuit, 233a... Transmission window.

Claims (1)

[Claims] It consists of an optical sensor consisting of a light-emitting element and a light-receiving element that detect dirt in the washing liquid, and a signal control circuit that controls washing or rinsing operation. 1. A control device for a washing machine, characterized in that the sensitivity of the optical sensor is adjusted during water supply before rinsing and agitation or during water supply before adding detergent.