JP3084717B2 - Washing machine - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a washing machine for automatically determining a water level during washing and rinsing.

2. Description of the Related Art In a conventional washing machine, the water level at the time of washing and rinsing is determined by setting the water level for each stage in accordance with the amount of cloth determined in about four stages from the load applied to the pulsator when the pulsator rotates.

Problems to be Solved by the Invention However, the optimum water level is determined by the quantity, quality, bulk and the like of the laundry, and the water level determination by the conventional method is insufficient.

The present invention has been made to solve the above-described problem, and has an object to determine an optimum water level from detection values of a cloth amount sensor and a water level sensor.

Means for Solving the Problems In order to achieve the above object, the present invention provides a laundry amount sensor for detecting the laundry amount of laundry, and water supply to an arbitrary water level can be terminated based on a detected value of the laundry amount sensor. A fuzzy inference device for inferring a function relating to the estimated water supply level indicating the degree of sex,
A water level sensor for detecting a water level, and control means, wherein the control means allows the water supply end possibility with respect to a water level rise rate derived from a rise rate at the time of water supply of the water level detected by the water level sensor at an arbitrary water level. Is compared with the function inferred from the fuzzy inferencer, and when the value of the function obtained from the water level rise rate becomes smaller than the value of the function inferred from the fuzzy inferencer, the water supply valve is closed and the water supply is terminated. Is what you do.

Operation The operation of the above means is as follows. First, the water supply expected water level is determined by a fuzzy inference unit from the detected value of the cloth amount sensor immediately before the water supply in the washing and rinsing steps. Next, the water supply is started, and the water level rise rate is detected from the detection value of the water level sensor. The water supply valve control means controls the water supply valve by comparing the expected water supply water level and the water level rise rate. The optimum water level is determined by such a process.

Example An example of the present invention will be described below. 1 and 2, reference numeral 1 denotes a washing tub for storing laundry and washing water, and 2 denotes an outer tub for storing washing water. Reference numeral 3 denotes a pulsator for stirring laundry and washing water, which is rotated by a motor 4 via a belt 5 and a mechanical mechanism 20. During dehydration, the washing tub 1 is driven by the motor 4. Reference numeral 6 denotes a cloth amount sensor that detects the rotation speed of the washing tub 1 by an encoder when the washing tub 1 rotates, and 7 denotes a water level sensor that detects the amount of water in the washing tub by detecting the air pressure in the air trap 8. The water in and out of the washing tub is controlled by a water supply valve 9 and a drain valve 10 driven by a solenoid valve.
Here, the cloth amount sensor 6 detects the weight of the cloth.
This is because the rotation speed of the washing tub 1 is determined by the weight of the cloth regardless of the bulk of the cloth.

Next, determination of the washing water level at the time of washing will be described with reference to FIG. The determination of the washing water level includes two stages: determination of an initial water supply scheduled water level and determination of water supply end during water supply. The determination of the first water supply scheduled water level is performed by the fuzzy inference unit 11 realized by the microcomputer 13. The inference at this time is
For example, the determination is made based on a determination made by a person who normally operates the washing machine, such as "the water level is high when the amount of cloth is high, or the water level is low when the amount of cloth is small". The inference rules consist of the four rules shown in FIG. Large amount of cloth
A qualitative concept such as "less" is quantitatively expressed by a membership function as shown in FIG. A qualitative concept such as "high" or "low" of the water level is also quantitatively expressed by a membership function as shown in FIG.

Next, a method of the inference operation will be described with reference to FIG. First, the cloth weight suitability calculating means 14 calculates the input, that is, the fitness of the antecedent part with respect to the detection value of the cloth quantity sensor 6, by using the input and the membership function stored in the cloth weight membership function storage means 15. It is determined by taking MAX. Next, in the consequent part minimum operation means 17, the water level rule storage means
Based on the rule stored in 16, the membership function stored in the water level membership function storage unit 18 and the antecedent part fitness MIN are taken, and the rule is concluded. After obtaining the respective conclusions for all the rules, the maximum calculation means 19 of the consequent part takes the MAX of all the conclusions, whereby the scheduled washing water level is obtained as the final conclusion. The scheduled washing water level is expressed in the form of a membership function as shown in FIG. 7 (a), and indicates the possibility that each water level is determined. Next, the water supply termination determination during the second water supply will be described with reference to FIG. First, the membership function of the planned water supply level shown in FIG. 7 (a) obtained in the first stage is integrated and normalized so that the maximum value of the grade becomes 1. This has a shape as shown in FIG. 7 (b), and indicates how likely the water supply is to end depending on the water level. Further, as shown in FIG. 8, the rising rate of the water level based on the detection value of the water level sensor during the water supply becomes smaller as the water level rises, and finally converges to a predetermined value. The decrease in the water level rise rate with the water level rise is due to the distribution of the cloth density generated when the laundry is vertically stacked in the washing tub 1. That is, the cloth density is highest at the bottom of the washing tub 1 and decreases as it goes upward. Further, the reason why the water level rise rate finally converges to the predetermined value is that the water level rise rate is determined by the size of the outer tub 2 after the laundry is completely immersed in water. Water supply end determination is made by comparing this water level rise rate with the above-mentioned planned water supply water level. As shown in FIG. 7 (c), when the rate of rise of the water level falls below the planned water supply level, the water supply is terminated and the water supply valve 9 is closed. The comparison operation and the control of the water supply valve are performed by the water supply control means 12 realized by the microcomputer 13. As can be easily understood from FIG. 7 (c), the water level is low if the cloth is low and the water level is high if the cloth is high, even if the expected water supply level is constant.

Here, the planned water supply level is represented by a fuzzy set, and the final water level is determined by comparison with the water level rise rate.However, a method of calculating the water level with respect to the center of gravity of the membership function of the planned water supply level obtained in the initial stage It is also possible to determine the water level as it is.

The process of determining the water level at the time of washing has been described above, but the determination of the water level at the time of rinsing can be similarly performed. By determining the water level in the above-described process, it is possible to obtain an optimum water level in consideration of both the weight and bulk of the laundry.

Effect of the Invention As described above, according to the present invention, the water level at the time of washing and rinsing can be determined based on multiple information such as the weight and bulk of the laundry. Fine washing and rinsing can be performed. Estimation of the water supply expected water level based on the detection value of the cloth amount sensor can be easily realized by fuzzy inference.

[Brief description of the drawings]

1 is a block diagram showing an embodiment of the present invention, FIG. 2 is a block diagram of the embodiment, FIG. 3 is a diagram showing rules of inference, and FIG. 4 is a membership function showing the amount of cloth. FIG. 5, FIG. 5 shows a membership function indicating a water level, FIG. 6 shows a configuration of a fuzzy inference device, FIG. 7 shows an explanatory diagram showing a process of determining a water level, and FIG. 8 shows a process of determining a water level. FIG. 1 ... washing tub, 2 ... outer tub, 3 ... pulsator, 4 ...
Motor 6 cloth amount sensor 7 water level sensor 9 water supply valve 11 fuzzy inference device 12 water supply valve control means

Continuation of the front page (56) References JP-A-61-98295 (JP, A) JP-A-1-274797 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) D06F 33 / 02 D06F 39/08 301

Claims (1)

(57) [Claims] A function relating to a cloth amount sensor for detecting a cloth amount of laundry and a water supply expected water level indicating a degree of possibility of water supply ending to an arbitrary water level is inferred from a detected value of the cloth amount sensor. A fuzzy inference device, a water level sensor for detecting a water level, and control means, wherein the control means controls the water level rise rate derived from the rise rate at the time of water supply of the water level detected by the water level sensor at an arbitrary water level. The water supply end possibility function is compared with a function inferred from the fuzzy inference device, and when the value of the function obtained from the water level rise rate becomes smaller than the value of the function inferred from the fuzzy inference device, the water supply valve Close the water supply to end the washing machine.