JPS6219198B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a laundry amount detection device for a washing machine that detects the amount of laundry based on instantaneous load fluctuations caused by laundry approaching and separating from an agitator such as an agitating blade.

Conventional methods for detecting the amount of laundry include the following. In other words, the amount of laundry becomes a load on the pulsator, and as the amount of laundry increases, the load on the pulsator also increases, so this method detects this load amount and determines the amount of laundry. It measures the current value of the motor that drives the pulsator, etc.

Since the rotational speed or current of the motor that drives the pulsator changes depending on the power supply voltage, motor temperature, and variations in characteristics between motors, the amount of change cannot be ignored.

Figure 1 shows the relationship between the amount of laundry and the current value of the motor when the amount of water is kept constant. Each is shown.

According to characteristic A, the average value of the current when there is no laundry and only water is loaded is 2A, but when the laundry weighs 2 kg, the increase in current is
It becomes 0.3A. When the temperature of the motor core rises to 60° C. as in characteristic B, it is no longer possible to distinguish between current fluctuations due to the amount of laundry and current changes due to temperature rise, and temperature correction becomes necessary. Similarly to the above, it is necessary to correct the current or stabilize the power supply voltage in response to changes in the power supply voltage supplied to the motor.

Furthermore, because the average difference between the no-load current and the current under load is small, variations between motors or variations in the characteristics of the belt used to connect the pulsator and motor cannot be ignored, and these must be managed. be.

In addition, as with the case where the average rotational speed of the pulsator or motor changes due to external factors such as current, a correction or stabilization circuit is required to detect the amount of laundry based on the rotational speed. do. In order to solve the various problems mentioned above, the laundry amount detection device naturally becomes complicated and expensive.

The present invention solves the above conventional problems, and includes means for detecting instantaneous load fluctuations applied to the stirring body within a set time, and means for determining the level of the load fluctuation value detected by the means. As a result, the amount of laundry can be detected with high accuracy without being affected by variations in power supply voltage, core temperature of the motors, or even characteristics between motors.

Examples of the present invention will be described below. Fig. 1 shows the general structure of a washing machine with dehydration and dehydration functions, in which 1 is the main body, 2 is an outer tank supported by vibration-proof hanging inside the main body 1, and 3 is the outer tank 2.
4 is a stirring blade arranged at the inner bottom of the washing tub 3; 5 is a motor; the rotational force is stirred by the switching operation of the clutch mechanism 6; The information is transmitted to the wing 4 or the washing tub 3. 7 is a clutch mechanism 6 that applies the rotational force of the motor 5.
8 is a drain port, and 9 is a drain hose outside the machine.

The basic operation of the washing machine configured as described above is already widely known, and its explanation will be omitted.

Here, in Figure 3, the water level is kept constant and only the amount of change in motor current is measured with respect to the amount of laundry. Figure C is when the amount of laundry is 1 kg, and C is when the amount of laundry is 2 kg.

As is clear from FIG. 3, the amplitude of the instantaneous change in motor current increases as the amount of laundry increases. Therefore, by measuring the amplitude of the instantaneous amount of change, it is possible to indirectly know the amount of laundry. The amplitude of the amount of instantaneous change is extremely complex and random depending on the material, shape, degree of entanglement of cloth, etc. of the laundry. In this method, the amount of laundry can be accurately detected by detecting the amount of instantaneous load change and detecting the number of times this detected value exceeds a predetermined set level within a set time.

Next, as a specific example, a case will be described in which the amount of change in motor current is detected. Figure 4 shows stirring blade 4
A block diagram is shown in which an AC induction motor is used as the drive motor 5, where 10 is a current detection unit consisting of, for example, a current transformer and a smoothing circuit for detecting the motor current, and 11 is a current detection unit that blocks the power frequency and detects the load. 12 is a rectifier that rectifies only the current component caused by the load and converts it into DC, 13 is an integrator for integrating the DC value, and 14 is a measurement time setting device. A timer 15 is used to gate the integrator 13 only during that period, and a comparator 15 is used to determine the set level together with the integrator 13, which constitutes the level determining means in the present invention. Determine the amount of laundry.

Here, the frequency spectrum of the fluctuation of the load applied to the stirring blade 4 is 30 Hz or less and does not extend to the power supply frequency, so the low frequency wave generator 11 is inserted. The rectifier 12 rectifies the amplitude of load fluctuation, but double-wave rectification is more desirable than single-wave rectification.

When the integrator 13 starts measuring, the integral value is gated to zero by the time setting timer 14. In addition, the output of the integrator 13 is as shown in FIG.
Indicates the integral value in Kg. Characteristics A, B in Fig. 5,
C, D, E, and F have laundry amounts of 0Kg, 0.8Kg, and 1.0
Corresponds to Kg, 1.5Kg, 2.0Kg, and 3.0Kg respectively. The comparator 15 is for determining the amount of laundry at time T. In FIG. 5, when V ₁ is characteristic C,
V ₂ indicates the amount of laundry in the case of characteristic E, and V ₃ indicates the amount of laundry in the case of characteristic F.

FIG. 6 shows an example of a flowchart when the comparator 15 is realized by, for example, an A/D converter and a microcomputer, and the amount of cloth is determined by the signal generated from the time setting timer 14 shown in FIG. ,
The integral output from the integrator 13 is read, and compared with a reference voltage, the amount of cloth is determined according to the value of the integral output read from the integrator 13, and an output corresponding to the amount of cloth is generated. Figure 6 shows an example of having two reference levels and determining the amount of cloth in three stages, but if you increase the number of reference levels, you can use the same method to judge the amount of cloth in finer detail. .

Also, other methods such as stirring blade 4 or motor 5 may be used.
Even with a method of detecting load fluctuations in the rotation of the motor, it is possible to detect the amount of cloth in the same manner as the detection of the motor current described above. That is, by providing a plurality of rotating magnet pieces attached to the stirring blade 4 and a magnetically sensitive element, such as a Hall effect element, a rotation speed detection unit that generates pulses in response to four rotations of the stirring blade is configured, The variation in rotational speed due to this can be detected by using signal processing as a time change in the pulse gap.
This can be done using normal circuit processing. The output of the rotation speed detection section is passed through an integrator and a comparator to detect the amount of laundry, similar to the motor current detection described above.

Further, as another method of signal processing, there is a method of determining the amount of laundry by measuring the number of times the detection signal of the current detection unit 10 shown in FIG. 4 reaches a set level or more within a set time. As shown in Fig. 7, for example, numerical values such as the number of times the set level V ₁ value is exceeded N ₁ , the number of times the V ₂ value is exceeded N ₂ , and the number of times the V _o value is exceeded N _o are statistically processed. In this way, it is also possible to determine the amount of laundry.

When the laundry is bulky and the washing tub is full, the load on the stirring blades 4 is continuous, as shown by V ₃ in characteristic F in Figure 5. is continuously braked by the laundry, and as a result, the output of the detection unit may not increase proportionally regardless of the increase in the amount of laundry.

In the case of such an overload, the average rotational speed in rotation detection and the average current consumption of motor current in current detection extremely decrease or increase. Therefore,
By processing these rotational speeds or currents and adding them to the integrator 13 or by controlling the set level of the comparator 15, it is possible to correct in case of overload.

FIG. 8 is a block diagram for detecting an excessive amount of laundry by detecting motor current. and comparator 15 are the same as shown in FIG.
The following measures have also been added. That is, 1
6 is the average current detection section of the motor 5, 17 is the comparator 1
This is a level controller for controlling the determination level of 5.

Then, by adding the output of the average current detection section 16 to the comparator 15, a result similar to the determination level setting in FIG. 4 can be obtained.

FIG. 9 shows a flowchart for the case according to FIG. According to FIG. 9, the reference voltage for determining the amount of cloth is determined based on the presence or absence of an excessive or undercurrent detection signal from the level controller 17 in the flowchart of FIG.
By adding a program to change V ₁ and V ₂ , when an excessive amount of laundry is loaded, the integrator 13
This allows for accurate determination even if the output voltage is small. Here, V ₁ >V ₁ ′, V ₂ >V ₂ ′.

In the above embodiment, a whirlpool type washing machine using an agitating blade was described, but it is also possible to use an agitating type washing machine in which the agitating blade is oscillated, or a rotating drum to rotate the laundry inside the washing machine. Even in a drum-type washing machine or the like, the same effects as those of the above-described embodiment can be achieved. In addition, in a drum-type washing machine, the rotating drum corresponds to the agitating blade as referred to in the present invention, and the agitating element includes the agitating blade, the rotating drum, and the like.

Furthermore, although this embodiment has been described with respect to a washing machine with both a dehydrating and dehydrating function, a so-called two-tub type washing machine in which a washing tub and a dehydrating tub are arranged side by side can also have the same effect as this embodiment.

As is clear from the above embodiments, according to the present invention, since the instantaneous load fluctuation value, which is the amplitude of load fluctuation that is not affected by variations in power supply voltage, temperature, motor characteristics, etc., is detected, the amount of laundry It is possible to detect load fluctuations with high precision, and to detect random instantaneous load fluctuation values within a set time, and determine the amount of laundry based on the average value of the values or the number of times the value exceeds a predetermined level. Compared to systems that make instantaneous judgments, it is possible to prevent erroneous judgments caused by disturbance noise, etc. Further, since the predetermined level is varied according to the absolute value of load fluctuation, for example, the motor current value, the amount of laundry can be accurately detected even when the laundry is bulky.

[Brief explanation of the drawing]

Fig. 1 is a diagram showing the relationship between the motor current value and the amount of laundry, Fig. 2 is a schematic cross-sectional view of a washing machine in an embodiment of the present invention, and Fig. 3 is a diagram showing the motor when the water level is constant and the load is varied. Figure 4 is a characteristic diagram showing changes in current; Figure A is when water is the only load, Figure B is when the amount of laundry is 1 kg, and Figure C is when the amount of laundry is 2 kg. 5 is a diagram showing the output state of the integrator in FIG. 4, FIG. 6 is a flowchart showing the operation of FIG. 4, and FIG. 7 is a diagram showing the amount of laundry to be washed. FIG. 8 is an electrical block diagram of a main part in another embodiment, and FIG. 9 is a flowchart for explaining its operation. 4... Stirring blade (stirring body), 5... Motor, 10
... Current detection section, 13 ... Integrator, 14 ... Time setting timer, 15 ... Comparator, 16 ... Average current detection section, 17 ... Level controller.

Claims (1)

[Scope of Claims] 1. Detecting means for detecting an instantaneous load fluctuation value that is the amplitude of load fluctuation applied to the agitating body; and determining means for determining the amount of laundry based on the instantaneous load fluctuation value detected by the detecting means. The determining means includes an integrator that averages load fluctuation values within a set time, and a comparator that compares and determines the output value of the integrator at a predetermined level and determines the amount of laundry. Quantity detection device. 2. The laundry amount detecting device for a washing machine according to claim 1, wherein the determining means varies a predetermined level according to the absolute value of the load fluctuation from the detecting means. 3 detection means for detecting an instantaneous load fluctuation value which is the amplitude of load fluctuation applied to the stirring body; means for detecting the number of times the instantaneous load fluctuation value from this detection means exceeds a predetermined level within a set time; A laundry amount detection device for a washing machine, comprising a determining means for determining the amount of laundry. 4. The laundry amount detecting device for a washing machine according to claim 3, wherein the means for detecting the number of times varies a predetermined level according to the absolute value of the load fluctuation from the detecting means.