Method for controlling washing machine

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Solution Overview

Problem

Conventional washing machines face challenges in uniformly dissolving detergent in wash water, leading to incomplete detergent dissolution and inefficient washing performance, especially at low water levels and in areas away from the drum rotation.

Innovation Solution

A method for controlling a washing machine that involves operating a circulation pump at varying speeds, accelerating and braking the washing motor to lift and drop laundry, and using nozzles to spray water effectively, ensuring detergent is uniformly dissolved and applied to laundry without incompletely dissolved detergent residues.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If water is supplied to a certain level in the drum to dissolve detergent through drum rotation, then detergent dissolution is achieved, but the water concentration level decreases due to absorption and additional water supply is required

Engineering Contradiction:
Improvedetergent concentrationVSAvoidwater level
Core Design Contradiction:
Quantity of substanceVSLoss of substance

Solution Approach 1:

The circulation pump operates before the drum rotation to dissolve detergent in advance by circulating water through the detergent solution. This preliminary dissolution action ensures that when water is later supplied to the drum, the detergent is already well-dissolved, preventing concentration loss from additional water supply needed to compensate for absorption.

Inventive Principle:
Principle #10Preliminary action

2Speed

If the circulation pump rotates at high speed to spray circulating water into the drum, then water reaches deep inside the drum, but it is difficult to form highly detergent concentrated wash water

Engineering Contradiction:
Improvecirculation pump speedVSAvoiddetergent concentration
Core Design Contradiction:
SpeedVSQuantity of substance

Solution Approach 1:

The circulation pump operates in periodic cycles: first at high speed to spray water deep into the drum for wetting laundry, then stops to allow detergent dissolution in the remaining water, creating highly concentrated wash water. This periodic alternation between high-speed spraying and stopping enables both deep water penetration and high detergent concentration formation.

Inventive Principle:
Principle #19Periodic action

3Area of stationary object

If water is circulated to spray into the drum region, then deep inside the drum is reached, but areas away from the drum such as drain bellows and pump housing are not influenced by drum rotation and detergent cannot be dissolved well

Engineering Contradiction:
Improvewater coverage areaVSAvoiddetergent dissolution
Core Design Contradiction:
Area of stationary objectVSQuantity of substance

Solution Approach 1:

The circulation pump acts as an intermediary device that independently circulates water through dedicated flow paths to reach areas not influenced by drum rotation, such as the drain bellows and pump housing. This separate circulation system ensures detergent dissolves uniformly in all areas including those away from the drum, without relying on drum rotation influence.

Inventive Principle:
Principle #24Intermediary (Mediator)

4Productivity

If the circulation pump operates continuously at high speed, then water circulation is maintained, but energy consumption increases and detergent dissolution efficiency decreases

Engineering Contradiction:
Improvewater circulation efficiencyVSAvoidenergy consumption
Core Design Contradiction:
ProductivityVSUse of energy by moving object

Solution Approach 1:

The circulation pump operates periodically rather than continuously: high-speed operation for water circulation and spraying, followed by stopping periods for detergent dissolution. This periodic operation reduces energy consumption compared to continuous high-speed operation while maintaining water circulation efficiency through alternating functional phases.

Inventive Principle:
Principle #19Periodic action

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This method achieves uniform detergent dissolution and improved washing performance by maintaining high detergent concentration in wash water, ensuring effective cleaning and reducing contamination from incompletely dissolved detergent.

Implementation Method 1

a circulation pump configured to circulate water discharged from the tub to the at least one nozzle

Methodology Applied
Scientific EffectPump: Pump

Implementation Method 2

at least one nozzle disposed in front of the drum to spray water toward the drum

Methodology Applied
Scientific EffectFluid spray: Fluid Spray

Implementation Method 3

accelerating and braking the washing motor to lift and drop laundry

Methodology Applied
Scientific EffectCentrifugal force: Centrifugal Force

Data Source

PatentEP3505667B1Method for controlling washing machine
Publication Date: 2020.08.19 LG ELECTRONICS INC
  • EP3505667B1 patent drawingFigure 1
  • EP3505667B1 patent drawingFigure 2
  • EP3505667B1 patent drawingFigure 3

AI summary

Disclosed is a method of controlling a washing machine having a tub for containing water, a drum rotatably provided in the tub, at least one nozzle disposed in front of the drum to spray water toward the drum, a washing motor configured to rotate the drum, and a circulation pump configured to circulate water discharged from the tub to the at least one nozzle, the method including: a step (a) of supplying water with detergent into the tub to a first water level; a step (b) of operating the circulation pump at a first speed such that the washing motor is repeatedly accelerated and braked while the circulation pump is operating at the first speed, causing laundry in the drum to be stuck to an inner circumferential surface of the drum in response to the acceleration of the washing motor and causing the laundry to fall from the inner circumferential surface of the drum in response to the deceleration of the washing motor, wherein the first speed is set within a range in which the water discharged from the circulation pump is not allowed to reach the at least one nozzle or, even if the water reaches the at least one nozzle, the sprayed water is not allowed to reach an inner circumferential surface of the drum; a step (c) of supplying water into the tub such that a level of water in the tub rises from the first water level to a second water level; and a step (d) of repeating acceleration and deceleration of the washing motor such that the circulation pump is accelerated in response to the acceleration of the washing moto, and the circulation pump is decelerated in response to the deceleration of the washing motor.