JPH0531294A - Abnormal vibration prevention method for washing machine - Google Patents

Abstract

(57) [Summary] [Purpose] Even if the laundry is a long one that is easily entangled during washing, the entanglement is relaxed to prevent abnormal vibration from occurring. In a drum type washing machine, a current value supplied to a drum drive motor 21 is detected by a meter relay 30 via an AC device 23 during balancing rotation for dispersing laundry before a dehydration process on an inner wall of a drum, If a current value above the set value is detected during a certain period of time immediately before the end of balancing, the drum is stopped at the end of the balancing process, and then the drum is rotated in the opposite direction at a low speed.
Repeat the balancing process again.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for preventing abnormal vibration of a washing machine which can be used in a centrifugal washing and dewatering machine such as a water washing machine and a dry cleaner.

[0002]

2. Description of the Related Art For example, in a dry cleaner for washing and drying laundry by using a solvent such as perchlorethylene, or a washing machine operating with water as a washing liquid, the laundry is put in a drum for washing. After that, the drum is rotated at high speed to remove the liquid by centrifugal force. At this time, if the laundry is unevenly distributed in the drum, a large vibration force is generated due to an unbalanced load on the laundry and the laundry is washed. As the device body vibrates,
This vibration may be transmitted to the surroundings through the ground and cause vibration pollution.

For example, in the conventional dry cleaner having the drive system shown in FIG. 3, the following method has been taken as one method for preventing this vibration pollution. That is, FIG. 3 shows an example of driving the processing drum. Reference numeral 2 is a cleaning motor for driving the drum 1 at a low speed during cleaning and drying, and 3 is centrifugal drainage by driving the drum 1 at a high speed during liquid removal. The liquid removing motor 4 is an electromagnetic clutch that disconnects the connection with the cleaning motor 2 when the liquid removing motor 3 is driven, 5, 6, 7, 8, 9, 10 are V pulleys, and 11, 12, 13 are V belts. Show. In FIG. 3, sensors such as an acceleration type vibration detector and a vibration displacement measuring device (not shown) are attached to the main body of the dry cleaner, and when the vibration exceeds the set value, the vibration monitoring circuit is activated and the drum 1 is driven by the liquid removing motor 3 The high speed rotation that is driven is once stopped, the unbalance of the laundry is corrected, and the drum 1 is again moved from the low speed rotation by the washing motor 2 to the high speed rotation by the liquid removing motor 3 to perform the liquid removal. In addition, it is 1-3
As disclosed in Japanese Patent No. 4639, means for detecting a current of a motor during balancing rotation, comparing a difference between a maximum value and a minimum value with a reference value, and repeating a balancing step when the difference is larger than the reference value is adopted. It had been.

[0004]

According to the above-mentioned conventional means, especially when the laundry is long and easily entangled during washing, the entanglement cannot be eliminated no matter how many times the balancing process is repeated, resulting in a large unbalance. Therefore, the loss of the operating time of the washing machine was large. The present invention aims to provide a method for preventing abnormal vibration of a washing machine, which can quickly eliminate an unbalanced state of laundry and shift to a dehydration step in a short time.

[0005]

Therefore, the present invention detects the current value supplied to the drum drive motor during the balancing rotation in which the laundry before the spin-drying process is dispersed on the inner wall of the drum in the drum type washing machine. If a means is provided and a current value equal to or higher than the set value is detected during a certain period of time immediately before the end of balancing, the drum is stopped at the end of the balancing process, and then the drum is rotated in the reverse direction at a low speed. The balancing step is repeated again, and this is used as a means for solving the problem.

[0006]

When the current value above the set value is detected during the fixed time immediately before the end of the balancing rotation, which determines the state of the laundry distribution on the inner wall of the drum, the drum is stopped at the end of the balancing process, and then continued. After rotating the drum in the opposite direction at a low speed to loosen the entanglement of the laundry, the balancing process is repeated again. This makes it possible to minimize the loss of operating time and prevent abnormal vibration from occurring after the dehydration transition.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the embodiments of the drawings. FIG. 1 shows an electric circuit diagram according to the embodiment of the present invention. In FIG. 1, reference numeral 21 is a drum drive motor, which is driven from a commercial AC power source 24 via an inverter control device 22 at a predetermined rotation speed and timing corresponding to each step of the washing machine. On the other hand, the current supplied to the motor 21 in operation can be detected by the meter relay 30 via the current transformer 23, and 31 is a relay instructing the detection timing. 32
Is a microcomputer control device, and when the meter relay 30 detects a current equal to or higher than a set value, the drum is stopped when the balancing process is completed, and then the drum is rotated in the opposite direction at a low speed to alleviate the entanglement of the laundry. After that, the balancing process is controlled again.

FIG. 2 shows an operation explanatory view. The sequence of shifting to the dewatering process starts with a tumbling process for draining the washing liquid. At this time, the rotational gravity acceleration ratio on the outer circumference of the drum is the same as during washing. It is 0.7G. The purpose of the balancing process is to disperse the laundry on the inner wall of the drum, and the rotation speed is higher than 1G (1.9G in this example). Disperse in the empty space of the clung laundry. On the other hand, the motor current during the balancing process also gradually changes depending on the dispersion state, but if the laundry has many entanglements, it shows a large current value until just before the end of balancing.

Therefore, in the embodiment of the present invention, the relay 31 is operated for 5 seconds immediately before the end of balancing to detect the motor current. At this time, if a current equal to or higher than the set value of the meter relay 30 is detected, the microcomputer controller 32 stops the drum at the end of the balancing process, and subsequently rotates the drum in the reverse direction at a low speed (0.7 G in this example), It issues a command to reduce the entanglement of laundry. After that, the balancing step is repeated again, and when the current value becomes less than or equal to the current setting value, the dehydration step is performed. Even if the vibration sensor attached to the main body of the washing machine operates after the dehydration process, the dehydration rotation is immediately stopped, the drum is rotated in the opposite direction at a low speed in the same manner as described above, and then the balancing process is repeated again. It is supposed to be.

[0010]

As described above in detail, according to the present invention, the unbalanced state of the laundry can be predicted during the balancing rotation before the dehydration step, abnormal vibration can be prevented from occurring, and the laundry is long. Even if the entanglement is easy, the drum automatically rotates in the opposite direction at a low speed when the balancing is restarted to reduce the entanglement, so that the loss of the operation time due to the repetition of the dehydration process can be minimized.

[Brief description of drawings]

FIG. 1 is an electric circuit diagram for implementing a method for preventing abnormal vibration of a washing machine according to an embodiment of the present invention.

FIG. 2 is an operation explanatory diagram of the present invention in FIG.

FIG. 3 is a diagram of a conventional drum drive system.

[Explanation of symbols]

 21 Drum Drive Motor 22 Inverter Control Device 23 Current Transformer 30 Meter Relay 32 Microcomputer Control Device

Claims (1)

Claim: What is claimed is: 1. A drum-type washing machine, comprising means for detecting a current value supplied to a drum drive motor during balancing rotation for dispersing laundry before dehydration on the inner wall of the drum. If a current value above the set value is detected during a certain period of time immediately before the end of balancing, the drum is stopped when the balancing process is completed, the drum is subsequently rotated in the opposite direction at a low speed, and then the balancing process is performed again. A method for preventing abnormal vibration of a washing machine, characterized in that the above steps are repeated.