JPS61185298A - Apparatus for detecting washing amount - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] "Industrial Application Field" The present invention relates to a laundry amount detection device that automatically detects the amount of laundry, and for example, automatically sets an appropriate water supply amount according to the amount of laundry in a fully automatic washing machine. used for.

"Prior Art" In an example of a conventional laundry amount detection device, a washing motor is operated with the water supply to the washing tub down to a predetermined low water level, and the steady value of the input current of the washing motor is measured. Determining the amount of laundry.

Since the input current of the washing motor is f+, which has a characteristic of increasing according to the amount of laundry, if the input current is large, it is determined that the amount of load, that is, the amount of laundry is large.

"Problems with the Prior Art" According to the conventional device described in G, the washing motor is operated until the input terminal reaches a steady value, which means that the laundry is constantly agitated. It is. However, since the water level is low at this time, if there is a lot of laundry, the amount of water for the laundry will be too small, and there is a risk that the laundry will be damaged. Moreover, since the above operation is repeated several times to ensure accuracy, there is a very high possibility that this will occur.

``Object of the Invention'' An object of the present invention is to provide a laundry amount detection device that can suitably detect the amount of laundry without causing damage to the laundry.

``Structure of the Invention'' The laundry amount detection device of the present invention is a device that supplies water to a predetermined low water level, agitates the laundry, and detects the amount of laundry based on the input current of the laundry motor at that time. A measurement command means for outputting a measurement command signal from the start of the motor to steady rotation, a current measurement means for measuring the input current of the washing motor based on the measurement command signal from the measurement command means, and the current measurement means. A feature of the constructor is that it includes a determining means for determining the amount of laundry based on the measured current value.

In the configuration described above, the measurement command means includes a washing motor rotation speed detection means and an output that outputs a measurement command signal when the rotation speed detected by the rotation speed detection means reaches a predetermined rotation speed smaller than the steady rotation speed. Examples include those consisting of means.

"Function" The inventor of the present invention conducted intensive research in view of the above object and found that even in the very initial input current characteristics at the time of starting a washing motor, characteristics corresponding to the amount of laundry appear.

In other words, an extremely large inrush current flows immediately after the laundry motor starts, but if you carefully observe the changes after that, you will notice that
A phenomenon is observed in which the current value temporarily becomes a minimum value, then gradually increases to a maximum value, and then decreases to a steady value as is known.

In this characteristic, the steady value corresponds to the load (it is well known that it increases), but surprisingly, the amount of laundry is already large at the stage when the current value increases from the minimum value to the maximum value. It was discovered that the characteristic that the current value becomes larger appears as the temperature increases.

Therefore, the inventor of the present invention focused on this point, conducted further research, and completed the present invention.

That is, in the present invention, the current value before the input current of the washing motor reaches a steady value is measured, and the amount of laundry can be determined based on the magnitude of the current value. Therefore, since it is not necessary to continue operating the washing motor until it reaches a steady state, the laundry is only slightly agitated, and as a result, damage to the laundry is suppressed.

"Example" The present invention will be further explained in detail below based on the example shown in the drawings. Here, FIG. 1 is a schematic structural explanatory diagram of a washing machine including a laundry amount detecting device according to the present invention, FIG. 2 is a circuit diagram of an embodiment of the laundry amount detecting device according to the present invention, and FIG. FIG. 4 is a characteristic diagram of the rotational speed and input current at the time of starting the motor in the washing machine shown in the figure, and FIG. Note that this invention is not limited to this.

The configuration of the washing machine 1 shown in FIG. 1 includes a water supply valve 2. Water level sensor 3. Washing and dehydration 14. Water tank 5. Drain valve 6, pulsator 7
, drive unit 8. Motor 9. Control circuit 10, motor input current detector 11. It basically consists of a motor rotation speed detector 12 and an operation unit 13. Each of these components, except for the control circuit 10, is the same as each conventionally known component.

The control circuit vP110 differs from conventionally known control circuits in that it has a laundry detection function according to the present invention.

As shown in FIG. 2, this control circuit 10 includes a rotational speed detection circuit 20. It basically consists of a current detection circuit 30 and a micro 1 viewer system 40.

The rotational speed detection circuit 20 shapes and integrates the signal from the rotational speed detector 12, which is a pulse signal whose number is proportional to the rotational speed n of the motor 9, and converts it into a voltage signal ■1. Comparator IC.

, IC2 are compared with respective comparison voltage signals E, , E2.

When the motor 9 is started, its rotational speed n increases monotonically from O to a steady speed, so the voltage signal vL produced from the output signal of the rotational speed detector 12 also becomes a signal that monotonically increases up to a steady voltage.

On the other hand, the comparison voltage EI of the comparator IC, is relatively small, and the comparison voltage E2 of the comparator IC2 is relatively large.

Therefore, when starting the motor 9, since the rotational speed n is O, the voltage signal ■, is also 0, and the comparator ■C1,
Both outputs of IC2 are "H".

When the motor 9 is started and its rotational speed n gradually increases, the output of the comparator IC+ is first inverted and becomes "L".

Then, when the rotation speed n further increases, comparator IC2
The output of is also inverted and becomes "L".

The output of the comparator IC is input to the current detection circuit 30, and the output of the comparator IC2 is input to the microcomputer system 40.

The current detection circuit 30 consists of a peak hold circuit and a manual switch that inputs the ground level or the output signal of the current detector 11 to the input of the peak hold circuit.

The input switch (transistor TRY) is controlled by the output of the comparator IC of the rotational speed detection circuit 20, that is, until the rotational speed n of the motor 9 inverts the output of the comparator IC to "L" level. The input of the peak hold circuit is forcibly lowered to the ground level, and the rotational speed n of the motor 9 increases to
The output signal of the current detector 11 is input to the peak hold circuit only after C is inverted to the "L" level.

Therefore, the output of the peak hold circuit is the maximum value of the current after the rotational speed n of the motor 9 reaches a speed n5 or higher at which the humpator IC is reversed. The machine has a function of inputting desired washing conditions and a function of controlling the water supply valve 2, drain valve 63, motor 9, etc. based on the input conditions to execute washing, but these functions are not conventionally known. The same is true. The functions of the microcomputer system 40 according to the present invention include a function of reading the output of the current detection circuit 30 when an "L" signal is input from the humpator IC 2, and determining the amount of laundry based on the value. , the operation will be comprehensively explained with reference to FIGS. 3 and 4.

FIG. 3 shows the rotational speed n and the input current 1 to the motor 9 when the motor 9 is started. It is a diagram showing the characteristics of change in (a
) shows when the amount of laundry is small, and (b) shows when the amount of laundry is large.

Immediately after power is applied to the motor 9, the rotational speed n is O, and the input terminal 1. An extremely large inrush current is flowing. However, the next moment the motor 9 starts rotating, and the input current IP rapidly decreases to a minimum value. From then on, as the rotational speed n increases, the input current decreases to ■.

gradually increases, and after reaching a certain maximum value, it begins to decrease and reaches a steady current value.

As can be understood from Figure 3, while the inrush current is flowing, the difference due to the amount of laundry cannot be detected, but once the minimum value after the inrush current is passed, the input current increases as the amount of laundry increases even at the same rotational speed n. It can be seen that l becomes large.

Therefore, if you read the value of the input current T at an appropriate timing after the inrush current disappears, you will get the input current ■.

The amount of laundry can be determined based on the size of the laundry.

In the rotational speed detection circuit 20 shown in FIG. 2, the comparison voltage E1 of the comparator IC1 is set corresponding to the rotational speed n1 after the inrush current disappears;
The second comparison voltage E is set corresponding to a suitable rotational speed n2 that is larger than the rotational speed n1 and smaller than the steady speed. As a specific example, nl is a 500 rpm culmness, which is achieved in about 0.1 seconds after the motor 9 is energized. Also, n2 is 11000rp#! degree, which is achieved within 0.3 to 1 second when the motor 9 is energized.

The characteristic curves (a) and (b) shown in Figure 3 are ideally drawn, but in reality there are small irregular fluctuations. In order to suppress the influence of such irregular small fluctuations, a peak hold circuit is employed in the current detection circuit 30.

The microcomputer system 40 uses a previously known amount of laundry and an input current 1. I remember the relationship between If the amount of laundry is unknown, the read input current 1. The amount of laundry is determined by comparing the value of with the stored relationship.

In this embodiment, the microcomputer 40 is
The boundary current value I0 between when it is determined that the amount of laundry is small and when it is determined that the amount of laundry is normal, and the boundary between when it is determined that the amount of laundry is normal and when it is determined that there is a large amount of laundry. The current value ■1 is memorized.

Therefore, as shown in FIG. 4, the read input current ■ is first set to the first boundary current value ■. If Ir is smaller than Io, it is determined that the amount of laundry is small.

If ■, is not smaller than Io, then the second boundary current (
ifI! If the amount of laundry is determined to be normal J, water supply valve 2 is turned on and additional water is supplied, and water is supplied to the middle water level. In other words, the water supply valve 2 is turned off.That is, when the amount of laundry is 1ffil, water is automatically supplied to the medium water level.

On the other hand, input current 1. is not smaller than the second boundary current value 11, it is determined that J has a large amount of laundry. In this case, water is supplied to a high water level.

In other words, when there is a large amount of laundry, water is automatically supplied to a high water level.

As mentioned above, this washing machine 1 automatically detects the laundry location and supplies water accordingly.

By the way, in the microcomputer system 40, the output of the comparator IC2 of the rotational speed detection circuit 20 is "L".
After the input terminal 1r is read from the current detection circuit 30 due to the inversion to the level, the power supply to the motor 9 is immediately stopped. In FIG. 3, the characteristic curves (a) and (b) show that the input current is 1.0 at the rotational speed n2. The fact that it falls on =Q represents this.

Therefore, the laundry is only slightly agitated, and even if the amount of laundry is disproportionately large for the low water level, there will be little damage to the laundry.

In order to accurately detect the amount of laundry, the above operation is repeated at least twice, and if the difference from the previous reading does not fall within an acceptable range, it is repeated one more time.

In this way - the above operation may be repeated several times, yet little damage to the laundry occurs.

As understood from the following description, the rotational speed detector 12
and rotational speed detection circuit 20 constitute measurement command means,
Further, the current detector 11 and the current detection circuit 30 constitute a current measuring means, and the microfum computer system 40
constitutes the determination means.

In another embodiment, the timing at which the input current of 1° to the motor 9 is read is determined based on the time from the start of energization to the motor 9 instead of the rotational speed. A specific example is one in which the maximum current value between 0.3 seconds and 1 second from the start of energization to the motor 9 is read.

Note that, contrary to the above, it is also possible to read the input current (2) in advance and determine the amount of laundry from the rotational speed n when it reaches a predetermined value. Although this example differs from the above-mentioned example in appearance, it is only that the rotational speed n and the current I are replaced with the insects, and it is essentially within the scope of the present invention.

"Effects of the Invention" According to the present invention, in a device that supplies water to a predetermined low water level, agitates the laundry, and detects the amount of laundry based on the input current of the laundry motor at that time, from the start of the laundry motor. A measurement command means for outputting a measurement command signal until steady rotation is achieved; a current measurement means for measuring the input current of the washing motor according to the measurement command signal from the measurement command means; There is provided a laundry amount detection device characterized by comprising a determining means for determining the amount of laundry based on the measured current value, and thereby the amount of laundry can be measured without stirring the laundry extensively. It has the effect of significantly reducing damage to laundry compared to conventional methods.

[Brief explanation of drawings]

FIG. 1 is a schematic structural explanatory diagram of a washing machine including a laundry amount detecting device according to the present invention, FIG. 2 is a circuit diagram of an embodiment of the laundry amount detecting device according to the present invention, and FIG. 3 is similar to FIG. FIG. 4 is a characteristic diagram of the rotational speed and input current at the time of starting the motor in the washing machine shown in FIG. (Explanation of symbols) l...Washing machine 2...Water valve 3...
Water level switch 7... Pulsator 9... Motor 12... Rotation speed detector 11... Current detector 10... Control circuit 20... Rotation speed detection circuit 30... Current detection circuit 40. ...Microcomputer system.

Claims (1)

[Claims] 1. In a device that supplies water to a predetermined low water level, agitates the laundry, and detects the amount of laundry based on the input current of the laundry motor at that time, the laundry motor starts to rotate steadily. measurement command means for outputting a measurement command signal until the
The present invention is characterized by comprising a current measuring means for measuring the input current of the washing motor based on a measurement command signal from the measurement command means, and a determining means for determining the amount of laundry based on the current value measured by the current measuring means. Laundry amount detection device. 2. The measurement command means includes a washing motor rotation speed detection means and an output means for outputting a measurement command signal when the rotation speed detected by the rotation speed detection means reaches a predetermined rotation speed smaller than the steady rotation speed. A laundry amount detection device according to claim 1.