Laundry machine and controlling method thereof

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Solution Overview

Problem

Laundry machines struggle to dry the inside of the tub and clean the predetermined space between the tub and drum effectively, leading to residual foreign substances and potential damage from overheating.

Innovation Solution

A laundry machine with a heater placed between the tub and drum, controlled to dry the tub interior and a method to circulate air for efficient drying, along with a check valve to prevent water backflow and a spraying path to clean the space between the tub and drum surfaces.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the tub is provided to hold water during washing, then washing function is achieved, but the tub cannot be completely dried and foreign substances remain between the drum and tub

Engineering Contradiction:
Improvewashing functionVSAvoidresidual foreign substances
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The patent applies preliminary action by performing a tub cleaning cycle before the main washing cycle. The control unit detects foreign substances in the tub and executes a preliminary cleaning operation to remove detergent residues and contaminants, ensuring the tub is clean before actual washing begins. This prevents contamination of laundry and maintains washing quality.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent implements self-service through the self-cleaning tub function where the tub cleans itself using circulating water and the rotation of the drum. The circulation pump moves water between the tub and sump, creating flow that washes the tub interior surfaces, eliminating the need for manual cleaning and automatically removing foreign substances.

Inventive Principle:
Principle #25Self-service

2Productivity

If heat generating means is actuated to dry the inside of the outer tub, then drying efficiency is improved, but risk of overheating and damage increases

Engineering Contradiction:
Improvedrying efficiencyVSAvoidoverheating damage
Core Design Contradiction:
ProductivityVSObject-affected harmful factors

Solution Approach 1:

The patent applies periodic action by operating the heater in intermittent cycles rather than continuously. The control unit activates the heater for predetermined time intervals, then pauses to allow cooling, preventing overheating while maintaining effective drying. This periodic heating pattern ensures the tub dries efficiently without exceeding safe temperature limits.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The patent implements feedback through temperature monitoring during the drying process. The control unit continuously monitors the temperature inside the tub and adjusts heater operation accordingly, reducing or stopping heating when temperature approaches dangerous levels. This feedback control prevents overheating damage while maintaining drying effectiveness.

Inventive Principle:
Principle #23Feedback

3Productivity

If a circulating stream of warm air is generated between the drum and tub, then drying performance is improved, but device complexity increases

Engineering Contradiction:
Improvedrying performanceVSAvoidair circulation system
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent applies self-service by utilizing the drum's own rotation to generate air circulation between the drum and tub. The rotating drum naturally creates airflow patterns that distribute warm air generated by the heater, eliminating the need for separate fans or complex air circulation mechanisms. This maintains drying performance while minimizing device complexity.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The patent implements multi-functionality by using the drum to serve dual purposes: both washing clothes and generating air circulation for tub drying. The same rotating component that performs the primary washing function also creates the airflow necessary for efficient drying, eliminating the need for dedicated drying mechanisms and reducing overall system complexity.

Inventive Principle:
Principle #6Universality (Multi-functionality)

4Manufacturing precision

If the drum is rotated during drying, then drying uniformity is improved, but energy consumption increases

Engineering Contradiction:
Improvedrying uniformityVSAvoidenergy consumption
Core Design Contradiction:
Manufacturing precisionVSUse of energy by moving object

Solution Approach 1:

The patent applies periodic action by rotating the drum in intermittent cycles during the drying process. The drum rotates for predetermined intervals to distribute heat evenly, then pauses to reduce energy consumption. This periodic rotation maintains drying uniformity across the tub interior while minimizing the total energy required for drum operation.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The patent maintains continuity of useful action by keeping the drum rotating at low speed throughout the drying process rather than stopping completely. This continuous low-speed rotation ensures uniform heat distribution and prevents localized overheating, while the low speed minimizes energy consumption compared to high-speed rotation.

Inventive Principle:
Principle #20Continuity of useful 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

The solution allows for efficient drying of the tub interior without auxiliary devices and effective cleaning of the space between the tub and drum, preventing overheating and residual substances, thus enhancing hygiene and machine longevity.

Implementation Method 1

a heater (6) provided in a laundry machine... driving the heater (6) to heat internal air of the tub (2)

Methodology Applied
Scientific EffectHeating: Heating

Implementation Method 2

rotating the drum (3) while the driving of the heater (6) is performed... the inside of the tub (2) may be dried quickly and uniformly

Methodology Applied
Scientific EffectConvection: Convection

Data Source

PatentEP2449161B1Laundry machine and controlling method thereof
Publication Date: 2022.01.12 LG ELECTRONICS INC
  • EP2449161B1 patent drawingFigure 1
  • EP2449161B1 patent drawingFigure 2~3
  • EP2449161B1 patent drawingFigure 4~5

AI summary

One of the controlling methods disclosed relates to control of a laundry machine including a tub and a drum, the method includes the steps of: sensing selection of a tub drying step and performing the tub drying step. The other controlling method of a laundry machine comprises the steps of: selecting a tub drying step; sensing door operation of the laundry machine; and performing the tub drying step based on the result of the door operation. Further, a laundry machine is disclosed that comprises a tub drying step selecting part configured to dry a tub (2); and a control part configured to control the tub (2) dried in case the tub drying step selecting part is selected.