Laundry care device with a control and method for the care of laundry

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Solution Overview

Problem

Conventional laundry care appliances struggle with uneven heating of laundry items, particularly those in the core of the drum, leading to inadequate contact with washing liquid and potential impairment of laundry care quality, and direct temperature measurement of laundry is complex or impossible.

Innovation Solution

A laundry care appliance with a control system that adjusts the rotational speed of the drum and heating of the washing liquid based on detected temperature differences, ensuring even heating of laundry by expelling and mixing washing liquid to indirectly determine the temperature of the laundry core.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If the drum rotates at different speeds to agitate laundry and transfer heat, then contact between laundry and washing liquid is improved, but the core laundry items do not receive sufficient heat transfer and temperature uniformity deteriorates

Engineering Contradiction:
Improvecontact between laundry and washing liquidVSAvoidtemperature uniformity of laundry
Core Design Contradiction:
Ease of operationVSTemperature

Solution Approach 1:

The system performs preliminary heating of the washing liquid before the main washing cycle, ensuring that the liquid is already at the required temperature before contacting the laundry. This preliminary thermal preparation allows even the core laundry items to be heated effectively when the drum rotates, solving the temperature uniformity problem while maintaining good contact.

Inventive Principle:
Principle #10Preliminary action

2Reliability

If washing liquid is heated to required temperature for laundry care, then laundry care quality is improved, but energy consumption increases

Engineering Contradiction:
Improvelaundry care qualityVSAvoidenergy consumption for heating
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The system uses temperature sensors to continuously monitor the temperature of the washing liquid and provides feedback to the control unit. The control unit adjusts the heating element operation based on this feedback, heating only until the required temperature is reached and maintaining it there, thereby ensuring laundry care quality while minimizing energy consumption through precise thermal control.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system replaces direct mechanical heating methods with a more efficient thermal exchange mechanism, where a heating element heats the washing liquid which then transfers heat to the laundry during drum rotation. This indirect thermal substitution improves energy efficiency while maintaining effective laundry care.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

3Measurement precision

If direct temperature measurement of laundry is implemented, then temperature control precision is improved, but device complexity increases

Engineering Contradiction:
Improvelaundry temperature measurementVSAvoidtemperature measurement system complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The system uses the washing liquid as an intermediary medium for temperature measurement. Instead of directly measuring laundry temperature, temperature sensors measure the washing liquid temperature, which serves as a reliable indicator of laundry temperature. This intermediary approach maintains measurement precision while avoiding the complexity of direct laundry temperature sensing.

Inventive Principle:
Principle #24Intermediary (Mediator)

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

Ensures even heating of all laundry items, including the core, with reduced energy consumption by optimizing the expulsion and mixing of washing liquid, eliminating the need for direct laundry temperature measurement.

Implementation Method 1

a heating element for heating the washing liquid in the tub

Methodology Applied
Scientific EffectHeating: Heating

Implementation Method 2

to activate the drum drive to rotate the laundry drum at a first expulsion speed during the first expulsion period in order to place the laundry held in the laundry drum against the laundry drum and to at least partially expel the washing liquid bound to the laundry from the laundry

Methodology Applied
Scientific EffectCentrifugal force: Centrifugal Force

Implementation Method 3

a temperature sensor which is designed to detect a temperature of washing liquid in the tub

Methodology Applied
Scientific EffectTemperature detection:

Implementation Method 4

ensuring the effective transfer of laundry care substances or heat from the washing liquid to the laundry

Methodology Applied
Scientific EffectHeat transfer: Conduction (thermal)

Data Source

PatentEP4261334B1Laundry care device with a control and method for the care of laundry
Publication Date: 2025.09.03 BSH HAUSGERATE GMBH
  • EP4261334B1 patent drawingFigure 1
  • EP4261334B1 patent drawingFigure 2
  • EP4261334B1 patent drawingFigure 3A~3B

AI summary

The present invention relates to a laundry care appliance (100) comprising a tub (105) for receiving washing liquid (129), a washing drum (107) for receiving laundry, wherein the washing drum (107) is arranged in the tub (105), a drum drive (109) for rotating the washing drum (107), a heating element (120) for heating the washing liquid (129) in the tub (105), a temperature sensor (123) for detecting the temperature of the washing liquid (129) in the tub (105), and a control unit (119) which is connected to the drum drive (109), the heating element (120), and the temperature sensor (123) for control purposes.The control unit (119) is configured to activate the drum drive (109) to rotate the washing drum (107) at a first ejection speed (159-1) during a first ejection period (157-1) in order to apply the laundry (127) held in the washing drum (107) to the washing drum (107) and to at least partially expel the washing liquid (129) bound to the laundry (127) from the laundry (127), wherein the temperature sensor (123) is configured to detect a temperature of washing liquid (129) in the tub (105) during the first ejection period (157-1).The control unit (119) is configured to detect a first and second temperature value (158, 160) of the washing liquid (129) during the first discharge period (157-1), to determine a temperature difference dT_mix (175) from the first and second temperature values, and during a second discharge period (157-2) following the first discharge period (157-1) to activate the drum drive (109) to rotate the washing drum (107) at a second discharge speed (159-2) in order to apply the laundry (127) received in the washing drum (107) to the washing drum (107) and to at least partially discharge the washing liquid (129) bound to the laundry (127) from the laundry (127) if the determined temperature difference dT_mix (175) is less than a target temperature difference.The control (119) is configured not to initiate a second sprouting period (157-2) after the first sprouting period (157-1) if the temperature difference dT_mix (175) determined during the first sprouting period (157-1) is greater than or equal to the target temperature difference.