Drum type washing machine and its control method

Abstract

The present invention provides a drum-type washing machine which features suppression of vibrations and noises during dehydration. To this end, an unbalanced load occurring around a rotation axis of the drum due to uneven distribution of laundry is canceled. More specifically, a plurality of water tanks (20) each having an opening on the inner periphery thereof are provided around the rotation axis on the back side of the drum (3). Where an eccentric load occurring due to the uneven distribution of the laundry is greater than an allowable level, a water supply valve (14) is opened to introduce water into the respective water tanks (20) with the drum 3 kept rotated, and the water is kept retained in the water tanks by a centrifugal force. Thereafter, the rotation speed of the drum (3) is temporarily reduced at a time point according to the position of the eccentric load to cause the water to fall only from water tanks (20) located at the same position as the position of the eccentric load or adjacent the position of the eccentric load for reduction of the weight of the water retained therein. The eccentric load occurring due to the uneven distribution of the laundry is canceled by an eccentric load generated by the water tanks not fully filled with the water and the other water tanks fully filled with the water, whereby the unbalanced load exerted on the entire drum (3) can be eliminated.

Description

[0001] The present invention relates to a drum-type washing machine having a drum which is rotated for washing and dehydration.PRIOR ART[0002] Conventional drum-type washing machines have a drum rotatable about a generally horizontal rotation axis within an outer tub, and laundry is retained in the drum.[0003] In such a conventional drum-type washing machine, an eccentric load is liable to occur due to uneven distribution of the laundry retained in the drum during dehydration thereby to cause vibrations and produce noises due to the vibrations. Particularly, greater vibrations occur at the start of the dehydration.[0004] Conventional measures for suppression of the vibrations occurring due to the uneven distribution of the laundry are to perform a disentangling process for disentangling the laundry in water retained in the drum before the dehydration and to support the outer tub by a damper which is capable of accommodating the eccentric load caused by the unevenly distributed laund...

AI Technical Summary

Benefits of technology

[0008] It is another object of the present invention to provide a drum-type washing machine which includes a mechanism for preventing vibrations and noises even if laundry is dehydrated in an unevenly distributed state.

[0009] It is further another object of the present invention to provide an improved drum-type washing machine which ensures that laundry can easily be loaded in and unloaded from a drum.

[0010] It is still another object of the present invention to provide a drum-type washing machine control method which suppresses vibrations and noises caused by an eccentric load occurring due to uneven distribution of laundry in a drum-type washing machine.

[0013] In accordance with a feature as set forth in claim 12, the magnitude of the eccentric load to be canceled can be reduced by performing a G-balancing operation for roughly distributing clustered laundry in the drum. Thus, the drum-type washing machine can perform a dehydrating process while suppressing vibrations and noises.

[0014] In accordance with a feature as set forth in claim 25, the drum is rotated while being tilted at an angle of not greater than 30 degrees with respect to a horizontal line. Thus, the drum-type washing machine ensures that the laundry can easily be loaded in and unloaded from the drum.

[0015] In accordance with a control method as set forth in claim 27, vibrations and noises can be suppressed which may be caused by an eccentric load occurring due to the uneven distribution of the laundry.

Problems solved by technology

In such a conventional drum-type washing machine, an eccentric load is liable to occur due to uneven distribution of the laundry retained in the drum during dehydration thereby to cause vibrations and produce noises due to the vibrations.

With these conventional measures, the vibrations occurring at the start of the dehydration can be alleviated, but the vibrations occurring during the dehydration cannot sufficiently be suppressed.

Accordingly, there is an inconvenience when the laundry is loaded in and unloaded from the drum.

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