Method for controlling washing machine

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Solution Overview

Problem

Existing washing machines fail to ensure even soaking of laundry due to inadequate control over the movement of laundry in response to varying water discharge from the circulation pump, leading to inconsistent washing performance.

Innovation Solution

A method that involves rotating the drum at varying speeds to lift and then brake laundry, synchronizing with the acceleration and deceleration of the circulation pump to optimize water spray direction and pressure, ensuring effective washing by applying a physical impact during the falling trigger motion.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Area of stationary object

If the circulation pump rotation speed is periodically changed to widen spray range, then water coverage area is improved, but laundry soaking uniformity deteriorates

Engineering Contradiction:
Improvespray rangeVSAvoidlaundry soaking uniformity
Core Design Contradiction:
Area of stationary objectVSManufacturing precision

Solution Approach 1:

The patent applies dynamics by making the drum rotation speed variable rather than constant. The control unit adjusts the drum rotation speed in real-time based on the circulation pump's water discharge amount, allowing the system to adapt to changing conditions and maintain optimal washing performance across different spray ranges.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent implements feedback control where the control unit continuously monitors the circulation pump rotation speed and adjusts the drum rotation speed accordingly. This closed-loop control ensures that the drum speed is synchronized with water discharge variations, maintaining uniform laundry soaking even when spray range changes.

Inventive Principle:
Principle #23Feedback

2Force

If the drum rotation speed is increased to lift laundry higher, then washing impact is improved, but energy consumption increases

Engineering Contradiction:
Improvewashing impactVSAvoidenergy consumption
Core Design Contradiction:
ForceVSUse of energy by moving object

Solution Approach 1:

The patent employs periodic action by alternating between high-speed rotation (for lifting laundry and creating washing impact) and low-speed rotation (for energy saving and water spraying). The control unit periodically varies the drum rotation speed based on the washing cycle phase, achieving effective washing while reducing overall energy consumption.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The patent changes the rotation speed parameter dynamically based on washing requirements. During phases requiring strong washing impact, the drum rotates at high speed; during phases requiring water distribution, the drum rotates at low speed. This parameter adjustment optimizes the balance between washing effectiveness and energy consumption.

Inventive Principle:
Principle #35Parameter changes

3Quantity of substance

If the circulation pump supplies water continuously, then water availability is improved, but laundry soaking uniformity deteriorates

Engineering Contradiction:
Improvewater supply amountVSAvoidlaundry soaking uniformity
Core Design Contradiction:
Quantity of substanceVSManufacturing precision

Solution Approach 1:

The patent uses periodic action by alternating between continuous water supply phases and intermittent water supply phases. The control unit synchronizes water supply with drum rotation, providing water during specific phases when laundry is in optimal positions for soaking, rather than supplying water continuously. This improves soaking uniformity while maintaining adequate water availability.

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 enhances washing performance by ensuring thorough soaking and cleaning through controlled drum and pump operations, improving the distribution and impact of water on laundry.

Implementation Method 1

a circulation pump which circulates water discharged from the water tub

Methodology Applied
Scientific EffectCirculation pump: Pump

Implementation Method 2

rotating the drum at a speed at which laundry on an inner circumferential surface of the drum is lifted without falling from the inner circumferential surface of the drum owing to a centrifugal force

Methodology Applied
Scientific EffectCentrifugal force: Centrifugal Force

Implementation Method 3

braking the drum such that the laundry falls from the inner circumferential surface of the drum

Methodology Applied
Scientific EffectBraking:

Implementation Method 4

increasing a rotation speed of the circulation pump while the laundry is lifted by the rotation of the drum, and decreasing the rotation speed of the circulation pump in response to the braking of the drum

Methodology Applied
Scientific EffectRotation speed control:

Data Source

PatentEP3505668B1Method for controlling washing machine
Publication Date: 2021.06.09 LG ELECTRONICS INC
  • EP3505668B1 patent drawingFigure 1
  • EP3505668B1 patent drawingFigure 2
  • EP3505668B1 patent drawingFigure 3

AI summary

Disclosed is a method for controlling a washing machine, the method including: a step (a) of rotating a drum at a speed at which laundry on an inner circumferential surface of the drum is lifted without falling from the inner circumferential surface of the drum owing to a centrifugal force while water is contained in a tub, and braking the drum such that the laundry falls from the inner circumferential surface of the drum; and a step (b) of increasing a rotation speed of a circulation pump while the laundry is lifted by the rotation of the drum, and decreasing the rotation speed of the circulation pump in response to the braking of the drum, wherein the step (a) is repeated with changing a rotation direction of the drum, and wherein the step (b) is repeated in response to the repetition of the step (a).