JPH0134639B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an over-vibration prevention device that prevents over-vibration during the dewatering process of a fully automatic washing machine, and particularly to a means for predicting the occurrence of over-vibration and taking measures in advance. Regarding.

[Conventional technology]

In a fully automatic washing machine, when a spin-drying process is executed, if the unbalance of the laundry is large, the spin-drying basket becomes over-vibrated. Conventionally, as an over-vibration prevention means for preventing such over-vibration, the over-vibration that actually occurs when the dehydration basket is rotated is disclosed in, for example, Japanese Utility Model Application No. 60-30788. The dehydration basket is detected using a limit switch such as a mechanical vibrating switch, and the detection signal is used to temporarily stop the dehydration basket, and then to rotate it again.

[Problem that the invention seeks to solve]

In the conventional means described above, the limit switch does not operate and detection is not performed until the rotation of the dehydration cage has increased considerably, that is, when the resonance point has been reached and the amplitude of the mechanism has become sufficiently large. Therefore, after the limit switch detects excessive vibration, it takes a relatively long time to stop the rotation of the dehydration basket and then restart the dehydration process from the beginning, resulting in a large time loss in the dehydration process. .

Therefore, the present invention can predict the occurrence of over-vibration due to unbalance of the laundry in the balancing process before starting the dehydration process, and can promptly eliminate the unbalanced state before over-vibration actually occurs, in a short time. An object of the present invention is to provide an over-vibration prevention device for a fully automatic washing machine that enables efficient dewatering.

[Means for solving problems]

In order to solve the above problems and achieve the objects, the present invention is characterized by taking the following measures.

(1) A current detector shall be installed to detect the current value supplied to the drive motor of the fully automatic washing machine.

(2) A means is provided for sampling the current value detected by the current detector over a predetermined period during the balancing process before the dehydration process.

(3) A means is provided for determining the difference between the maximum value and the minimum value of the current values sampled by this means.

(4) A means is provided to compare the difference obtained by this means with a preset reference value.

(5) A means is provided for repeating the balancing process when the difference is larger than a reference value as a result of comparison by the comparison means.

[Effect]

By taking the above measures, the following effects occur. When the laundry is unbalanced, the ripple width of the current supplied to the drive motor becomes larger even in the initial state of rotation than when the laundry is unbalanced. Therefore,
By determining the difference between the maximum and minimum current values sampled during the initial state of rotation, that is, the balancing process, and comparing that difference with a preset reference value, it is possible to detect the difference before overvibration actually occurs. , it is possible to accurately predict the occurrence of overvibration. If overvibration is predicted to occur, the balancing step is immediately performed again at that point, so the unbalanced state is quickly resolved.

〔Example〕

FIG. 1 is a block diagram showing the configuration of one embodiment of the present invention. In FIG. 1, reference numeral 1 denotes a commercial AC power supply, and AC power is supplied from this power supply 1 to a drive motor 4 via a switch 2 and a sequence control circuit 3. As is well known, the sequence control circuit 3 performs sequence control so that each process such as pre-washing, main-washing, rinsing, washing processes such as draining, balancing process, dehydration process, etc. is executed at a predetermined timing. .

A current detector 5 is attached to the drive motor 4 to detect the current supplied to the drive motor 4. This current detector 5 is composed of, for example, a current transformer, and its output is sent to a sampling circuit 6.
given to. The sampling circuit 6 receives a sampling start signal S from the sequence control circuit 3.
1 starts the sampling operation, and the sampling end signal S2 from the control circuit 33 ends the sampling operation. The current value sampled by the sampling circuit 6 is supplied to the memory 7. The memory 7 is composed of, for example, a RAM, and temporarily stores sampling current values having a current value accuracy of about 0.1 ampere. The sampling current value stored in the memory 7 is stored in the arithmetic unit 8 when the sampling end signal S2 is sent from the sequence control circuit 3.
is read out. The arithmetic unit 8 calculates the difference A between the maximum value and the minimum value of the read sampling current value. The difference A calculated by the calculator 8 becomes one input of the comparator 9. As the other input of the comparator 9, a reference value B preset by a reference value setter 10 is applied. The comparator 9 compares the two inputs, and if the difference A is larger than the reference value B, it determines that an over-vibration has occurred, and outputs an over-vibration prediction signal C. This over-vibration prediction signal C is given to the balancing repetition command unit 11. When this command device 11 is given the above-mentioned over-vibration prediction signal C, it gives a command D to the sequence control circuit 3 to repeat the balancing process. Note that the output signal of the comparator 9 is also supplied to the counter 12. This counter 12 counts the number of times the output signal C is sent from the comparator 9. For example, when the output signal C is sent out repeatedly five times or more, it turns off the switch 2 and corrects the unbalanced state of the laundry. This is to give you an opportunity to make corrections again using manual operations. Note that in FIG. 1, the portion surrounded by a broken line is composed of a microcomputer or the like.

Next, the operation of this device configured as described above will be explained in a second step.
This will be explained with reference to the figures below. As shown in FIG. 2, when the switch 2 is turned on at time t1, AC power from the power source 1 is supplied to the drive motor 4 via the sequence control circuit 3. Therefore, the motor 4 rotates and the washing process is started. When the washing process ends at time t2,
After the water is drained by the action of the sequence control circuit 3, the process moves to a balancing process. In this balancing step, the dehydration basket rotates at a low speed of about 1 revolution per second so that the laundry is balanced within the dehydration basket. Assume that the laundry is unbalanced and the current I supplied to the drive motor 4 is pulsating as shown in FIG. This current value I
is detected by the current detector 5 and supplied to the sampling circuit 6. When a certain time point t3 is reached immediately before the end of the balancing process, a sampling start signal S1 is applied from the sequence control circuit 3 to the sampling circuit 6. Then, as shown in FIG. 3, the sampling circuit 6 performs sampling with a width of 25 mS for about 2 seconds until time t4. This sampling current value is sequentially stored in the memory 7. When the sampling end signal S2 is sent from the sequence control circuit 3 at time t4, the above sampling operation ends. At the same time, the sampling current value stored in the memory 7 is read into the computing unit 8, and as shown in FIG. 3, the difference A between the maximum value I-max and the minimum value I-min of the sampling current value is is calculated. This difference A is compared with a reference value B in a comparator 9, and if A>B, an overvibration prediction signal C is output. Then, the balancing repetition command signal D is given from the balancing repetition command unit 11 to the sequence control circuit 3. As a result, the balancing process is performed again from the beginning. Normally, the above-mentioned balancing process is repeated two or three times.
When the laundry is rotated, the unbalance of the laundry is resolved. By eliminating the unbalance, the ripple in the current value supplied to the drive motor 4 becomes smaller, and the difference A
When the relationship between and the reference value B becomes A<B, the comparator 9
The overvibration prediction signal C from is not sent out. Therefore, the repeated command signal D from the command unit 11 is also not outputted as indicated by the X mark in FIG. In this manner, the sequence control circuit 3 moves to the next step, the dehydration step. However, for some reason, the imbalance may not be resolved. Therefore, in this embodiment, when the output signal from the comparator 9 is repeatedly sent out about 5 times, the counter 12 detects it and prohibits the operation of the balancing repeat command 11 using the counter output. 2. In this case, the cause of the unbalance can be removed by manual operation and then restarted.

FIG. 4 is a diagram showing the rotation state of the dehydration basket in the above operation. As shown in FIG. 4, in this embodiment, when excessive vibration is predicted to occur due to unbalanced laundry, the rotation speed begins to decrease from time t4, and past time t5, when the first balancing process ends. Immediately after, at time t6, the balancing process is restarted from the beginning. Therefore, the time required to perform a repeated operation is only T1. On the other hand, in the conventional method, for example, at time t
The limit switch only works when the rotation of the dehydration basket increases considerably as shown in step 7. Moreover, it takes a long time for the rotation speed of the dehydration basket to return to zero. Therefore, the time required to perform a repeated operation is T2, which is much larger than T1,
It will be a big time loss. In this way, according to this embodiment, the unbalanced state is quickly resolved.

It should be noted that the present invention is not limited to the one embodiment described above, and it goes without saying that various modifications can be made without departing from the gist of the present invention.

〔Effect of the invention〕

According to the present invention, in the balancing process before starting the dewatering process, if the ripple width of the drive motor supply current is larger than normal, the occurrence of excessive vibration due to unbalance of the laundry is predicted,
This fully automatic washing machine is configured to immediately restart the balancing process from the beginning before over-vibration actually occurs, so the unbalanced state is quickly resolved, enabling efficient spin-drying in a short time. It is possible to provide an over-vibration prevention device.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the configuration of an embodiment of the present invention, FIG. 2 is a diagram showing the operation timing of the embodiment, and FIG. 3 is a diagram showing means for detecting the current ripple width of the embodiment. FIG. 4 is an explanatory diagram of the operation of the same embodiment. 1...Commercial AC power supply, 2...Switch, 3...
Sequence control circuit, 4... Drive motor, 5...
Current detector, 6... Sampling circuit, 7... Memory, 8... Arithmetic unit, 9... Comparator, 10... Reference value setter, 11... Balancing repetition command unit, 12... Counter.

Claims (1)

[Claims] 1. A current detector for detecting the current value supplied to the drive motor of a fully automatic washing machine, and means for sampling the current value detected by the current detector over a predetermined period during the balancing process before the dehydration process. , means for determining the difference between the maximum and minimum current values sampled by this means, means for comparing the difference determined by this means with a preset reference value, and the result of the comparison by this comparing means. An over-vibration prevention device for a fully automatic washing machine, comprising means for repeating the balancing process when the difference is larger than a reference value.