CROSS-REFERENCE TO RELATED APPLICATION

This application claims the priority benefit of Korean Patent Application No. 10-2018-0047041, filed on Apr. 24, 2018, the disclosure of which is incorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a control method of a washing machine having a circulation pump circulating wash water.

2. Description of the Related Art

Generally, a washing machine is an apparatus that separates contaminants from clothes, bedding, and the like (hereinafter, referred to as “laundry”) by using chemical decomposition of water and detergent and physical action such as friction between water and laundry.

Such a washing machine includes a tub containing water and a drum rotatably provided in the tub to accommodate the laundry. Recent washing machines are configured to circulate water discharged from the tub by using a circulation pump, and to spray the circulated water into the drum through a nozzle.

In recent years, new technologies have been developed to control the rotation of the drum so as to impart variety to the flow of laundry introduced into the drum. Further, technologies for improving the washing effect by controlling the water pressure sprayed through the nozzle also have been developed.

SUMMARY OF THE INVENTION

The present invention has been made in view of the above problems, and provides a control method of a washing machine for performing a highly concentrated washing process in the early stage of washing and performing a strong spray washing process in the middle and late stages of washing.

The present invention further provides a control method of a washing machine which can actively perform water supply and circulation spraying in accordance with a quantity of a waste and a porosity.

In accordance with an aspect of the present invention, a method of controlling a washing machine includes: sensing a laundry amount accommodated in a drum; performing water supply into the drum according to the sensed laundry amount; rotating a pump motor at a certain initial rotation speed and transferring washing water discharged from the drum to at least one nozzle for spraying water into the drum; sensing a water level in the drum; performing a re-supply of water at least once until the sensed water level reaches a set water level; and increasing the rotation speed of the pump motor whenever the re-supply of water is performed.

As the rotation speed of the pump motor increases, a reach range of water stream sprayed through the at least one nozzle is gradually moved from a front surface of the drum toward a rear surface.

The method of controlling a washing machine further includes rotating the pump motor at a set maximum rotation speed, after the water level of the washing water reaches the set water level.

The maximum rotation speed is set to be higher as the sensed laundry amount becomes larger.

The rotation speed increase range of the pump motor due to the re-supply of water increases, as the sensed laundry amount becomes larger.

An initial rotation speed of the pump motor is set to be higher, as the sensed laundry amount becomes larger.

The set water level is set to be higher, as the sensed laundry amount becomes larger.

The water level in the drum is sensed in a state where a washing motor for rotating the drum is turned off.

The method of controlling a washing machine further includes performing additional water supply, when the water level in the drum is lowered below a certain water level after the re-supply of water is performed and the water level reaches the set water level.

The rotation of the pump motor is repeatedly performed intermittently.

The rotation speed of the pump motor is uniformly maintained while the re-supply of water is achieved.

In the water stream sprayed through the at least one nozzle, the water stream that is sprayed as the rotation speed of the pump motor increases reaches from a side surface portion of the drum to a rear surface portion thereof.

The washing machine includes: a tub disposed in a casing and having an opening formed on a front surface thereof; a pump having the pump motor; an annular gasket connecting the casing and the opening of the tub; and a nozzle water pipe fixed to the gasket for guiding water pumped by the pump to the at least one nozzle.

The nozzle water pipe includes: a circulation pipe connection port connected to the pump to supply the pumped water; and a transfer conduit connected to the circulation pipe connection port and guiding the water introduced through the circulation pipe connection port to the nozzle.

The transfer conduit is formed in an annular shape where a part of an upper end of a circumference is incised, and the water pumped to the circulation pipe connection port positioned at the lower end of the transfer conduit is branched and guided in both directions through the transfer conduit.

The transfer conduit is formed in an annular shape where a part of an upper end of a circumference is incised, and the at least one nozzle includes: a pair of intermediate nozzles, which is disposed above a center of the gasket, for spraying the water stream downward; and a pair of lower nozzles, which is disposed below the center of the gasket, for spraying the water stream upward.

The pair of intermediate nozzles and the pair of lower nozzles are connected to both left and right sides of the transfer conduit so that water introduced into the transfer conduit is sprayed into the drum through the pair of intermediate nozzles and the pair of lower nozzles.

The circulation pipe connection port is positioned at a lower end of the transfer conduit, and the water pumped to the circulation pipe connection port is branched and guided in both directions through the transfer conduit.

The washing machine includes: a tub disposed in a casing and having an opening formed on a front surface thereof; and an annular gasket connecting the casing and the opening of the tub.

The method of controlling a washing machine further includes spraying water supplied through a water supply valve into the drum through a direct water nozzle when the re-supply of water is performed.

