JPH0448069B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a method for detecting the amount of laundry in a washing machine.

(Prior art) Conventionally, methods of detecting this type of washing machine based on changes in the current of the motor that drives the rotary blades of the washing machine, and methods of detecting based on changes in the rotational speed of the rotary blades or the motor have been proposed. It had been.

For example, according to Japanese Patent Publication No. 59-36556, before starting the washing operation, a certain amount of water is supplied and drained to give the laundry an appropriate amount of moisture, and then the spin-drying operation is performed. A method is adopted in which the amount of laundry is detected by detecting a change in motor drive current and comparing it with a preset reference value.

However, in this case, the range of change in motor current is very small compared to the total current, and measurement values vary due to variations in the motor and capacitor capacity used, the movement of the amount of laundry in contact with the rotary blades, etc. There was a problem where the amount could not be detected.

Therefore, as a means to solve the above problem, for example, Japanese Patent Application Laid-Open No. 61-238291 and Japanese Utility Model Application No. 61-100382
Something like the No. 1 publication was proposed. That is, in both cases, the drive current of the motor is detected, the average value of this current is determined, and based on that average value,
This method detects the amount of laundry.

In addition to current, there is a method of detecting the amount of laundry based on the average number of rotations of the stirring blades.

(Problems to be Solved by the Invention) However, the method of calculating the average value as described above and detecting the amount of laundry based on this average value has the following problems.

Figure 3 is a model diagram showing the change in the rotational speed of the agitating blade when the washing motor is turned on.If the cloth is being agitated in a normal state without any tilting of the cloth or lifting of the cloth, each Although variations occur in the number of revolutions, the variations are small, but when a lump of cloth in which the cloth is twisted comes into contact with the stirring blade, the number of revolutions of the stirring blade becomes extremely large, as shown by a4 in Figure 3. When the number of rotations decreases and, conversely, the fabric no longer comes into contact with the stirring blades due to the fabric floating, the rotational speed of the stirring blades changes from the normal rotational speed (a1 to a3, a in Figure 3).
5, a6). Now, when the change shown in Figure 3 is shown, in the conventional method, the average value is calculated including the rotation speed a4, and the average value at this time is affected by the bias of the cloth. value. In addition, even in the conventional method, if the number of horizontal flips is significantly increased to obtain the average value, it is possible to obtain the average value A, which is less affected by cloth twisting, etc., but this method takes a long time to detect the amount of laundry. The problem is that it is necessary.

In short, in the conventional method, the amount of laundry is determined based on the average value that is affected by the bias of the cloth, the lifting of the cloth, etc. when the detection is performed for a short time, and the amount of laundry is determined based on the erroneous determination result. There is a risk that process control may be required, and it is not possible to detect the amount of laundry with high accuracy in a short period of time.

However, the present invention provides a laundry amount detection device that can exhibit high detection accuracy in a short period of time.

(Means for Solving the Problems) The contents of the present invention will be explained below using drawings corresponding to embodiments.

The stirring blade 2 is reversed left and right by the washing motor 3, the number of revolutions of the stirring blade 2 during each rotation is detected and stored by a signal from the rotation detection unit 4, and the average value of the stored values for a predetermined number of times is determined. This average value is compared with each stored value, the stored values that are more than a reference value away from the average value are removed, the average value of the remaining stored values is determined, and the amount of laundry is determined based on the average value.

Note that the present invention is not limited to detecting the rotational speed of the stirring blade as in the illustrated embodiment, but can also detect the rotational speed of the stirring blade, current of the washing motor, power consumption, etc., which changes due to changes in the load applied to the stirring blade. It can be implemented in the same way even if it is something that does.

(Function) In the above method, by setting the reference value to an appropriate value in advance based on experimental data, etc.
Values affected by the bias of the cloth, lifting of the cloth, etc. can be removed, and an average value can be determined from appropriate values. Therefore, the average value obtained is a value that is not affected by the bias of the cloth or the lifting of the cloth even if it is detected for a short time (value A in Figure 3 or an approximate value thereof), and the amount of laundry to be washed is determined based on this value. This means that the judgment can be made accurately.

(Embodiment) FIG. 1 is a block diagram showing a control system of a washing machine in an embodiment of the present invention. In the figure, 1 is a washing tub, 2 is a stirring blade that stirs the laundry and water, 3 is a washing motor that rotates the stirring blade 2, and 4 is a stirring blade 2.
A rotation detection unit that detects the rotation speed of the center pulley 5 that rotates integrally with The light from the light-emitting element to the light-receiving element is intermittent and a pulse signal corresponding to the rotation speed is obtained. Reference numeral 6 denotes means for measuring the rotation speed of the stirring blade 2 using a pulse signal output from the rotation detection section 4 when the washing motor 3 is turned on, means for storing the rotation speed measured by the means, and a memorized value for a predetermined number of times ( means for calculating the average value of the rotation speed), means for comparing the above average value with the stored value for each time, and excluding stored values that are different from the average value by more than a reference value, and means for re-calculating the average value of the remaining stored values. , and a means for determining the amount of laundry based on the average value obtained again and outputting a signal according to the determined amount. Reference numeral 7 denotes a controller that controls the execution time of processes such as washing and rinsing, water flow, etc. in accordance with the output signal of the laundry amount detection device 6.

Next, detection of the amount of laundry will be explained according to the flowchart of FIG. 2.

During the period of detecting the amount of laundry, the controller 7 controls the washing motor 3 on and off at a preset cycle, and reverses the stirring blades 2 left and right. Therefore, the rotation speed of the stirring blade 2 during the ON time of the washing motor 3
Measure ai and memorize the rotation speed ai for each ON time.
After measuring the rotation speed ai for a predetermined number of times Ni,
Calculate the average value of the rotational speed ai for Ni, compare this average value a with the rotational speed ai of each time, and compare the rotational speed ai that is more than the reference value from the average value (for example, a
4) Exclude. Next, the rotation speed a4 is excluded from the stored rotation speed ai of each rotation, and the average value of the remaining rotation speeds ai is determined again. The average value obtained in this manner is a value that is not affected by the bias of the cloth, the floating of the cloth, etc. (for example, A in FIG. 3 or an approximate value thereof).
Therefore, by determining the amount of laundry based on this average value, the determination becomes highly accurate.

Note that the present invention is not limited to detecting the rotational speed of the stirring blade as in the illustrated embodiment, but is also applicable to detecting the rotational speed of the stirring blade, current of the washing motor, power consumption, etc., which changes due to changes in the load applied to the stirring blade. This method can also be applied to devices that detect values.

(Effects of the Invention) As described above, according to the present invention, values affected by fabric bias, fabric lifting, etc. are excluded, the remaining values are used to obtain an average value, and the amount of laundry is calculated based on the average value. By being able to make a determination, high detection accuracy can be achieved even in a short period of time.

[Brief explanation of the drawing]

Fig. 1 is a block diagram showing the control system of a washing machine according to an embodiment of the present invention, Fig. 2 is a flowchart for detecting the amount of laundry, and Fig. 3 is a model showing changes in the rotational speed of the stirring blade when the washing motor is turned on. FIG. 2... Stirring blade, 3... Washing motor, 4... Rotation detection unit, 6... Laundry amount detection device.

Claims (1)

[Claims] 1 Rotate the stirring blades left and right using the washing motor,
The values of the rotational speed of the stirring blade or the current of the washing motor, etc., which change due to load fluctuations applied to the stirring blade during each rotation, are memorized, the average value of the stored values for a predetermined number of rotations is calculated, and the washing is performed from this average value. In the laundry amount detection method for determining the amount of laundry, the average value of the stored values for the predetermined number of times is compared with the stored value for each time, and the distance from the average value is at least a reference value determined in advance based on experimental data etc. Excluding the stored value, calculate the average value again from the remaining stored values, and use this as the new average value.
A method for detecting the amount of laundry in a washing machine, characterized by determining the amount of laundry based on this new average value.