Washing Machine Detergent Dosing by Detected Water Volume

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Solution Overview

Problem

Existing washing machines often experience inaccurate dosing of treatment agents due to varying laundry loads and water absorption properties, leading to potential overdosing or underdosing, which is critical in hygienically sensitive applications.

Innovation Solution

A control device that adjusts the dosing of treatment agents based on the detected quantity of fresh water supplied, ensuring precise dosing by dividing the process into two phases: an initial dosing with a fixed amount followed by a variable dosing adjustment to maintain the predetermined concentration ratio of fresh water and treatment agent.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If dosing is based on nominal load quantity, then dosing is simplified, but dosing accuracy deteriorates due to varying actual loads and water absorption properties

Engineering Contradiction:
Improvedosing operationVSAvoiddosing accuracy
Core Design Contradiction:
Ease of operationVSMeasurement precision

Solution Approach 1:

The control device receives feedback from the sensor device about the actual water quantity in the tub and adjusts the treatment agent dosing accordingly. The control device calculates the required treatment agent quantity based on the detected water amount and controls the dosing pump to deliver the precise amount, ensuring accurate dosing despite variations in load size and water absorption.

Inventive Principle:
Principle #23Feedback

2Reliability

If dosing is increased to account for potential underloading, then dosing safety is improved, but overdosing occurs leading to waste and environmental harm

Engineering Contradiction:
Improvedosing reliabilityVSAvoidtreatment agent waste
Core Design Contradiction:
ReliabilityVSLoss of substance

Solution Approach 1:

The sensor device measures the actual water quantity in the tub and provides feedback to the control device. The control device uses this feedback to calculate and deliver the exact treatment agent quantity needed, preventing both overdosing and underdosing. This ensures reliable dosing without waste, as the system adapts to the actual water amount rather than using fixed or excessive dosing amounts.

Inventive Principle:
Principle #23Feedback

3Loss of energy

If water quantity is reduced to save resources, then resource efficiency is improved, but dosing accuracy deteriorates due to insufficient treatment agent concentration

Engineering Contradiction:
Improvewater consumptionVSAvoidconcentration precision
Core Design Contradiction:
Loss of energyVSManufacturing precision

Solution Approach 1:

The control device dynamically adjusts the treatment agent dosing quantity based on the detected water amount. When water quantity is reduced for energy savings, the control device proportionally reduces the treatment agent dosing to maintain the correct concentration ratio. This ensures that even with reduced water consumption, the treatment agent concentration remains precise and effective.

Inventive Principle:
Principle #35Parameter changes

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 approach ensures precise dosing adapted to different loads and water levels, preventing overdosing, enhancing environmental and cost efficiency while ensuring process safety in applications requiring specific concentrations.

Implementation Method 1

a metering pump for conveying the treatment agent through the supply line into the tub

Methodology Applied
Scientific EffectPump: Pump

Implementation Method 2

a sensor device for detecting the amount of washing liquid in the tub

Methodology Applied
Scientific EffectLevel detection:

Implementation Method 3

a valve for controlling or releasing and blocking the water supply through the supply line

Methodology Applied
Scientific EffectValve: Valve

Data Source

PatentEP3828328B1Washing machine comprising a device for adding treatment agent
Publication Date: 2022.09.28 MIELE & CO KG
  • EP3828328B1 patent drawingFigure 1
  • EP3828328B1 patent drawingFigure 2

AI summary

The invention relates to a washing machine with a cylindrical tub (2) arranged in a housing (4) and a drum (3) rotatably mounted within the tub (2) and driven by a drive motor (13) for receiving the laundry items to be treated; - an inlet line (23, 26) for supplying fresh water from an external water supply to the tub (2); - a valve (15) for controlling or releasing and blocking the water supply through the inlet line (23, 26); - a device (8) for dispensing treatment agent (81), for example detergent, into the tub (2) with a reservoir (85) for treatment agent (81), a supply line (83) and a metering pump (82) for conveying the treatment agent (81) through the supply line (83) into the tub (2); - a sensor device (71) for measuring the amount of washing liquid (72) in the tub (2);- a control unit (18) for controlling the valve (15), the drive motor (13) and the metering pump (82). The control unit (18) is designed and programmed to control the metering pump (82) and thus the quantity of treatment agent (81) to be metered, depending on the measured quantity of fresh water (72) supplied to the lye tank (2).