CN1085266C - Autocontrolled washer - Google Patents

Abstract

In order to avoid spin-drying under the condition that brake foam exists in the washing liquid tank, the present invention proposes to input a signal to the control circuit of the washing machine during the spin-drying process. caused by foam) and is determined by the ratio of the following operating parameters of the drive motor: a) the rated number of revolutions, b) the actual number of revolutions, c) a load-dependent electrical parameter. This ensures reliable detection and elimination of foam.

Description

automatic washing machine

The invention relates to an automatic control washing machine with a driving motor. The number of rotations of the driving motor can be controlled by a rotation number control circuit according to the principle of phase cutoff control and can be determined according to the rated number of rotations and the actual number of rotations. The motor is used for driving Washing drum with various rotation speeds for washing, rinsing and drying.

In a known washing machine of this type (German patent DE 36 38 498 A1), in order to determine the presence of foam, the pressure present in the tank of the washing machine is measured with a pressure sensor for determining the liquid level, so that it is concluded that there is foam or No frothy conclusion. However, it has been proved that the pressure shock generated from the four sides of the washing liquid pump to the remaining water in the liquid tank will also cause the liquid level of the washing liquid in the washing liquid tank to rise falsely, so that the drying process is not allowed at all, resulting in drying stop. So, this way of identifying bubbles is unreliable. Furthermore, simultaneous detection of liquid level and foam with pressure sensors requires at least one additional changeover switch, thus increasing the component outlay.

The object of the present invention is to provide a solution for reliably detecting foam without using additional components.

The present invention accomplishes this task like this: in the spin-drying process, the control circuit of washing machine can input a signal, and this signal is to determine a measure that washing drum does not wish to brake (causing, for example, due to foam) and is driven by the following operation of motor Depends on the scale of the parameter:

a) Rated speed,

b) the actual number of revolutions,

c) An electrical parameter related to the load.

The rotation value always exists as an electrical parameter in the rotation number control circuit of modern washing machines, and the electrical parameter related to the load can also be the value of the motor current in the rotation number control circuit or the phase cut-off angle of the motor current. Therefore, The present invention does not require any additional components to identify foam.

The washing machine according to the invention can be modified in a particularly advantageous manner: when inputting a signal that assumes there is a suds volume of the brake drum, the spin-drying drive of the washing drum can be stopped for at least a certain period of time. During the time when the spinning drive is stopped, foam may be broken at the bottom of the washing liquid tank. According to another advantageous development of the washing machine according to the invention, the remaining washing liquid fraction can be drawn out by the washing liquid pump during the idle time of the spin-drying drive.

According to another advantageous structure of the washing machine of the present invention, during the stop time of the spin-drying drive, the drum can reverse the acceleration transmission process, so as to accelerate the bursting of the foam. The overdrive process is usually done at a very low RPM so that the drum motion does not create further foam, but rather bursts the existing foam.

Another advantageous development of the washing machine according to the invention is that effective remedial measures can be taken in the presence of a large amount of suds, that is, a rinsing process can also be carried out after the definite suds volume has been determined. Dense foam or a large amount of foam will cause a large braking torque on the drum, and the magnitude of this torque can be estimated fairly reliably from the above three parameters. Depending on the amount of foam determined in this way, one or another measure can be taken. Depending on the measures taken, a rinsing process with an increased liquid level can be carried out in a particularly advantageous manner even at the start of another rinsing process.

The relationship between the spin-drying process and the generation of foam will be described below in conjunction with the relationship curves of motor revolutions and motor current versus time shown in the accompanying drawings.

1 and 2 show the relationship between the motor current i and the time t and the corresponding drum revolution n and the time t. The phase cut-off angle is proportional to the motor current driving the drum, and the phase cut-off angle as a control parameter can be directly given by the control circuit of the drum driving motor.

All curves shown in the graph were obtained from tests in the same washing machine with the same laundry. In the graph of FIG. 1 , the laundry has been rinsed well at the beginning of the spin-drying process, and there is no suds-forming surfactant residue in the washing liquid remaining on the laundry. When the drive motor is switched on and as it accelerates to about 100 rpm, the motor current spikes up to 4.5A and then stops at about 1.2A. Upon further acceleration from 100 rpm to approximately 240 rpm, the needle-like rise in motor current i decreases significantly (to approximately 2.4 A). At this time, the inertial influence of the clothes that have started to move is reduced. At a resting speed of about 240 rpm, the motor current drops to 1.4A, and as the motor speed ramps up to about 800 rpm, the motor current only slowly rises above 1.5A. While the drum rotation rate was maintained at about 800 rpm, the motor current was reduced to 1.5A. After a short stop current peak, the motor current i drops to 0 again and the speed drops rapidly to 0 revolutions per minute.

If the measured static current is greater than 0A, it is because the total current consumption of the washing machine was measured when the current curve was recorded. However, the power consumption when the motor is not connected is only about 500mA, so it can be ignored compared with the high power consumption of driving the motor.

The laundry observed in the curve record of Fig. 2 also contains foamy washing liquid. The current curve is basically the same as the curve in Figure 1 during the initial stage of drying until it reaches about 220 revolutions per minute, but because there is already some foam between the washing liquid tank and the rotating washing drum, it is flat at the number of revolutions The power consumption during the 100 rpm segment and the current drop after the needle-shaped peak when accelerating to about 220 rpm are significantly higher than the corresponding line segments in Figure 2. When testing according to Fig. 2, starting from 220 revolutions per minute in the gentle section, the washing drum first linearly accelerates to about t=2 minutes, while the braking foam obviously hinders the drum. This means that the motor current increases sharply beyond approximately 4.5A to reach its power limit, at which point it is no longer possible for the drum to accelerate further against the braking torque generated by the foam. Therefore, the drum rotation speed is maintained at approximately 400 revolutions per minute. This fact causes two obvious disadvantages: on the one hand, the load on the drum motor is often too high (for example, the actual power consumption can reach 750W instead of the rated power of 300W), so that the motor overheats and wears out prematurely; on the other hand, the clothes are often Spinning is carried out at a reduced spin speed, so the spin is not sufficient. In addition, the spun-off wash liquor mechanically brought in by the spin-drying drum causes further suds formation, ie it is more difficult to eliminate suds. After the drive has stopped, the motor current and the number of revolutions of the washing drum drop back to zero.

分钟时的提前中止而例如不同于图1大于4分钟乃是由于与产生泡沫根本没有关系的程序改变所致。When recording the curves of FIGS. 3 and 4 , the drive motor is controlled by the control circuit according to the invention which can input a signal which is a measure of undesired braking of the washing drum, for example due to foam. It can be seen from the figure that the ratio of the number of revolutions to the required motor current value gives approximately the same results in the tests according to the curve of Figure 3 (assuming the same amount of laundry and the same conditions). As for the smooth section between 700 and 800 revolutions per minute at about

Early aborts at minutes other than, for example, greater than 4 minutes in Figure 1 are due to program changes that have nothing to do with foam generation at all.

As shown in Figure 4, the control circuit of the present invention stops the initial spin-drying stage in the rising section above 400 revolutions per minute, because the motor current rises far beyond 4.5A, and the number of revolutions is no longer the theoretical curve shown in Figure 3 . From this it can be concluded that the washing drum is excessively loaded due to external influences, for example due to suds braking. In order to monitor this undesirable operating condition, an increase in the motor current itself or an increase in the phase cut-off angle of the motor supply and an increase in the ratio of rated to actual revolutions can be observed from the graph. According to an advantageous further development of the invention, further conclusions can be drawn about the current program run from this cessation of the spin start. It may be important first to stop the spin-drying drive of the drum for a certain period of time. Preferably, the washing liquid pump of the washing machine continues to rotate during the stop of the spin-drying drive, so that the washing liquid accumulated by the foam to be eliminated can immediately flow out of the washing liquid tank. The washing liquid that is not in the washing liquid tank can no longer participate in the further formation of foam.

Furthermore, in order to avoid foam formation during a subsequent spin-drying process, at least one rinsing process should be carried out after determining the amount of brake foam in the washer fluid tank. Such a rinsing cycle further reduces the residual surfactant content of the wash liquor and reduces the risk of re-suds formation. A new spin-start test can be performed after the rinse cycle has ended. This rinsing process with increased washer fluid level can be carried out as many times as desired.

It is especially valuable for the operation of the washing machine if the braking caused by detergent foam can be considered from the beginning. Therefore, a device is considered in the control circuit to store the time to stop the spin-start test when the foam is generated. The number of times and from the certain frequency of these times add a corresponding number of rinsing process with the learned experience value to the number of times of rinsing process set by the manufacturer at the beginning for the future operation process. However, it would be beneficial to test the number of rinsing cycles set by the manufacturer after a certain number of operating cycles, in order to test out whether the operators have changed their operating behavior, for example by changing the detergent. In addition, there is another way, that is, the control circuit can be designed to work in principle according to the number of rinsing processes and the spin-drying start-up test set by the manufacturer, but before the next spin-drying start-up test, the first start-up test must Appends a rinse cycle count corresponding to the learned experience value.

Claims (13)

1. the automatic control washing machine that has a drive motor, the revolution of its motor can be controlled with a revolution control circuit, and can determine by rated revolution and actual revolution, this motor is used for driving laundry, the cleaning-drum of several different revolutions in rinsing and the drying process, it is characterized in that, the control circuit of washing machine can be imported a signal in the drying process, this signal is to measure the yardstick that cleaning-drum produces undesirable braking (for example owing to produce foam cause) also can determine from the mutual ratio of the following operational factor of drive motor:

A) rated revolution,

B) actual revolution,

C) with the relevant electric parameter of loading.

2. washing machine according to claim 1 is characterized in that, the revolution control circuit is the revolution control circuit based on phase angle control, and the electric parameter relevant with load is the phase angle angle of drive motor supply voltage.

3. washing machine according to claim 1 is characterized in that, the revolution control circuit is the revolution control circuit based on copped wave control, and the electric parameter relevant with load is the current drain of drive motor.

4. according to claim 1,2 or 3 described washing machines, it is characterized in that when adding had the signal of the parameter that the foam volume that can determine to cause drum braking exists, the drying drive unit of cylinder can stop the regular hour at least.

5. washing machine according to claim 4 is characterized in that, in the time that the drying drive unit stops, the washing liquid pump can continue to be driven.

6. washing machine according to claim 4 is characterized in that, in the time that the drying drive unit stops, cylinder can be reversed and quicken to drive.

7. washing machine according to claim 5 is characterized in that, in the time that the drying drive unit stops, cylinder can be reversed and quicken to drive.

8. according to claim 1-3, described washing machine one of among the 5-7 is characterized in that, is determining that the foam volume that causes braking can carry out another rinse cycle later at least.

9. washing machine according to claim 4 is characterized in that, is determining that the foam volume that causes braking can carry out another rinse cycle later at least.

10. washing machine according to claim 8 is characterized in that, can have the rinse cycle again and/or several times that improves the cleaning solution liquid level.

11. washing machine according to claim 9 is characterized in that, can have the rinse cycle again and/or several times that improves the cleaning solution liquid level.

12. washing machine according to claim 8, it is characterized in that, control circuit has a device to be used for store drying the starting test number of times, and from the certain frequency of these number of times to operating process in the future for the rinse cycle number of times of having set by producer at the beginning add one with the corresponding rinsing number of times of the empirical value of acquiring or before drying starting test next time this experience rinsing number of times of acquiring of setting.

13. according to described washing machine one of among the claim 9-11, it is characterized in that, control circuit has a device to be used for store drying the starting test number of times, and from the certain frequency of these number of times to operating process in the future for the rinse cycle number of times of having set by producer at the beginning add one with the corresponding rinsing number of times of the empirical value of acquiring or before drying starting test next time this experience rinsing number of times of acquiring of setting.

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