JPS6151918B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method of controlling a washing machine in which a rotary tub is intermittently driven by a motor in order to prevent an increase in residual bubbles during a dehydration process immediately after washing.

Conventionally, there is a method known as a suds removal/dehydration process in which a dehydration process is performed immediately after washing to remove as much detergent as possible from the laundry prior to rinsing. Conventionally, in such foam removal and dewatering, if the rotating tank is rotated at high speed from the beginning,
In order to prevent bubbles from accumulating in the outer tank all at once and causing rotational resistance of the rotating tank, the motor that drives the rotating tank is energized intermittently to gradually increase the speed of the rotating tank. I have to.
However, in conventional systems, the ratio of the motor's energization time to power-off time, that is, the duty cycle, is fixed by a timer and is matched to the rated amount of laundry, so the intermittent drive period of the rotary tub is long. In the case of a small amount of laundry, the extra intermittent driving time becomes wasted time. In addition, since the speed increase rate of the rotating tub is set extremely slowly to match the rated amount of laundry, it takes a long time for the rotating tub to pass through the resonant rotational speed section, and the vibrations during this period continue for a long time, causing the laundry to deteriorate. It has the disadvantage that it tends to change to an unbalanced distribution.

The present invention has been made to eliminate the above-mentioned drawbacks, and its purpose is to control the duty cycle regarding energization and disconnection of a motor for intermittently driving a rotating tank in accordance with the degree of decrease in acceleration of the rotating tank. By doing so, the speed increase rate of the rotating tub can be changed according to the amount of laundry, and the intermittent drive period becomes a value that corresponds to the amount of laundry, eliminating wasteful intermittent driving time and reducing the rotating tub operating time such as spin-drying time. Control of a washing machine that can shorten the time and reduce the frequency of occurrence of abnormal vibrations due to a change to an unbalanced distribution by shortening the passage time in the resonance rotation speed section especially when a small amount of laundry is easily changed to an unbalanced distribution. The purpose is to provide a method.

An embodiment in which the present invention is applied to a dehydrating and washing machine controlled by an electronic circuit will be described below.
FIG. 1 shows the basic structure of a washing machine with dehydrating function. In FIG. 1, reference numeral 1 denotes an outer box, inside of which a water receiving tank 2 is suspended by an elastic support mechanism 3, and within the water receiving tank 2, a rotating tank 4 with dehydration holes formed around it is disposed. A stirring blade 5 is provided inside the stirring blade. Reference numeral 6 denotes a motor that selectively drives the rotating tank 4 and the stirring blades 5. Reference numeral 7 denotes a drainage hose connected from the bottom of the water receiving tank 2 through a drainage valve 8. Reference numeral 9 denotes rotational speed detection means, which comprises a striped disc 10 that rotates together with the rotating tank 4, and a speed pulse generator 11 that optically detects the passage of the strip through the slit and generates a speed pulse P1. On the other hand, the electronic control circuit 12 shown in FIG. ) 14, a clock control circuit 15, a memory 16, an input buffer control circuit 17, and an output buffer control circuit 18. In the external input section A, 19 is a power switch that supplies power to the entire device, 20 is a lid switch, 21 is a water level switch that detects the water level in the water receiving tank 2, and 22 is a program for selecting the content of the stroke combination. This is a selection switch, and each state is determined by a state conversion element 23 such as a flip-flop circuit.
26 to logical values (0) and (1), respectively. The external input section A also includes the speed pulse generator 11, and its output signal, the speed pulse P1, is supplied to the input buffer control circuit 17. In the external output section B, 27 is a water supply valve, 6 is the motor, 8 is the drain valve, and 28 and 29 are an indicator lamp to notify abnormal dehydration and an indicator to notify the end of the washing machine operation, respectively. Each part in the external output section B is a switching element 30 such as a thyristor.
The energization is controlled by 34 to 34. The arithmetic processing unit 14 includes state conversion elements 23 to 2 corresponding to the state of each part in the external input section A.
6 through the input buffer control circuit 17 and the process data from the memory 16, washing (including water supply), draining, foam removal and dehydration, rinsing (including water supply), dehydration, The output buffer control circuit 18 judges the process of notification, etc., and controls each part of the external output section B necessary for executing the process by giving signals to the switching elements 30 to 34 from the output buffer control circuit 18. The method is the same as a known method except for the control method of foam removal and dehydration.

However, the method of the present invention is to control the drive of the rotary tank 4 so as to have the characteristics shown in FIG. 4 during the foam removal and dewatering process which is carried out immediately after the washing process. In FIG. 4, N on the vertical axis is the rotation speed of the rotating tank 4, T on the horizontal axis is time, and 35 is a characteristic curve showing the no-load speed characteristic of the rotating tank 4 when the motor 6 is continuously energized from the time of startup. 36 is a characteristic curve showing the speed characteristics of the rotating tank 4 when controlled according to the present invention. In the present invention, the rotation tank 4 is intermittently driven by turning on and off the motor 6 during the foam removal and dewatering process, so that the acceleration A of the rotation tank 4 is set to the set acceleration A ₀ during the energization period TA of the motor 6. Motor 6
The power is cut off for a predetermined power cut-off period TB.
Later, the motor 6 is controlled by repeating the process of energizing the motor 6 again until the rotating tank 4 drops to the set acceleration A ₀ , and the position where the set acceleration A ₀ is reached is shown in Fig. 4 as D1. ,D2...
It is shown in Such intermittent drive control is performed by the electronic control circuit 12, which will be explained with reference to FIG. 3, which is a functional block diagram for convenience. In FIG. 3, the acceleration determination section 37 receives a speed pulse P1 with a frequency proportional to the rotation speed of the rotating tank 4 from the speed pulse generator 11 and a timing pulse P2, and receives a speed pulse P1 within a unit time by the timing pulse P2. The acceleration A of the rotating tank 4 is determined from the change in the number of arrivals of P1, and a detected acceleration signal P3 is output. Reference numeral 38 denotes a comparison section, which receives the detected acceleration signal P3 and the set acceleration signal P4 corresponding to the set acceleration A ₀ preset in the acceleration setting section 39, and compares them.
When A becomes ₀ , an off signal P5 is output. 4
0 is a motor control unit that disconnects power to the motor 6 for the predetermined power-off period TB from the time it receives the off signal _P5 and starts energizing it again. Off signal P5
Continue until you receive it. In this way, the rotating tank 4 is intermittently driven by the power on/off control of the motor 6, and its rotational speed gradually increases until it reaches a predetermined rotational speed Na (see Fig. 4). The acceleration determination prohibition signal P6 is outputted from the rotation speed determining section 41, thereby stopping the action of the acceleration determining section 37 and shifting the motor 6 to continuous energization. This acceleration determination prohibition signal P6 is generated when the rotation speed determination section 41 receives a speed signal P7 corresponding to the rotation speed Na and a speed pulse P1 from the first speed setting section 42 and compares them. As a result of continuous energization after the acceleration determination action has stopped, the rotating tank 4 reaches the set rotation speed Nb (see Fig. 4) (Na<Nb).
When the time reaches the above value, the continuous dehydration time determining section 43 outputs the time setting signal P8. This time setting signal P
8 is generated when the continuous dehydration time determining section 43 receives the speed signal P9 corresponding to the set rotational speed Nb set in the second speed setting section 44 and the speed pulse P1 and compares them. In this way, when the rotating tank 4 reaches the set rotational speed Nb and the time setting signal P8 is generated, this time setting signal P8 is set for a constant continuous drive period TD according to its own time element.
The motor control unit 40 is operated to further energize the motor 6 continuously (see FIG. 4), and then the dewatering operation is stopped. As a result, the execution time of the bubble removal and dehydration process is the total time of the intermittent driving period TC and the continuous driving period TD. According to this device controlled in this manner, the energization period TA in the duty cycle regarding energization and de-energization of the motor 6 is determined by the change in the acceleration A of the rotating tub 4, so that the amount of laundry can be controlled. As is clear from the characteristic curve 45, which is shown for a state with less laundry than the characteristic curve 36, the speed increase rate of the rotating tub 4 increases as the amount of laundry decreases and as dehydration progresses. Therefore, the intermittent drive period TC also becomes shorter as the amount of laundry decreases and dehydration progresses (TC +
The effect is that the execution time of the dehydration process (TD) is shortened. Along with this, the passage time in the resonance rotation speed section is only the longest when the amount of laundry is rated, and in most other cases it becomes shorter as the amount of laundry decreases, so even if the amount of laundry is small. It becomes difficult to change to an unbalanced distribution, and the frequency of occurrence of abnormal vibrations decreases. By the way, in FIG. 3, 46 is a duty cycle determination section shown as an embodiment, which receives time width signals corresponding to the energization period TA and the energization period TB from the motor control section 40, and determines the time duration signals corresponding to the energization period TA and the de-energization period TB. The duty cycle (TA/TB) is determined, and when it is below a set value (for example, a characteristic that is below the characteristic curve 36 in FIG. 4), an alarm signal P10 is outputted and an abnormality is notified by the display lamp 28. It's becoming like that. This can prevent abnormalities in the rate of speed increase of the rotating tub 4, such as when the amount of laundry is too large or when a large amount of foam is generated.

In the above configuration, the relationship between the rotation speed Na for stopping acceleration detection and the rotation speed Nb for transitioning to the continuous drive period TD is (Na<Nb), but even if (Na=Nb) good.

As described above, the present invention controls the duty cycle related to energization/disconnection of the motor for intermittently driving the rotary tank in accordance with the degree of decrease in acceleration of the rotary tank. can be changed according to the amount of laundry, and the intermittent driving period becomes a value according to the amount of laundry, eliminating wasted intermittent driving time, reducing the rotating tank operating time such as spin-drying time, and especially changing the unbalanced distribution. It is possible to provide a method for controlling a washing machine in which the passage time of the resonance rotation speed section becomes shorter when a small amount of laundry is easily washed, thereby reducing the frequency of occurrence of abnormal vibrations due to a change to an unbalanced distribution.

[Brief explanation of the drawing]

Fig. 1 is a theoretical longitudinal cross-sectional side view of a washing machine with a dehydrating function showing an embodiment of the present invention, Fig. 2 is an overall block diagram of the control circuit, Fig. 3 is a block diagram of the main control portion, and Fig. 3 is a block diagram of the control circuit. Figure 4 is a speed characteristic diagram of the rotating tank. In the figure, 4 is a rotating tank, 6 is a motor, 12 is an electronic control circuit, 37 is an acceleration determination circuit, 40 is a motor control section, 43 is a continuous dewatering time determination section, and 46 is a duty cycle determination section.

Claims (1)

[Scope of Claims] 1. In a washing machine in which the rotating tub is intermittently driven and controlled by a motor for a predetermined period of time during spin-drying, the acceleration of the rotating tub is detected, and the detected acceleration has decreased to a set acceleration. 1. A method of controlling a washing machine, characterized in that the motor is repeatedly de-energized after a predetermined period of time and then re-energized until a predetermined number of revolutions is reached. 2. The method of controlling a washing machine according to claim 1, characterized in that the continuous energization period of the motor is determined to be constant from the time when the rotating tub reaches a predetermined number of rotations. . 3. The method for controlling a washing machine according to claim 1, wherein a notification is generated when a duty cycle related to energization/disconnection of the motor is equal to or less than a set value.