Dishwasher Detergent Holder Water Filling via Pump Speed Feedback

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Solution Overview

Problem

Existing methods for determining the precise amount of water needed for stable operation in dishwashers result in unstable pump operation, noise, and inefficiencies due to rapid water intake and high computing demands, or prolonged water inflow times, especially when dealing with varying loads of items to be washed.

Innovation Solution

A method that calculates the missing water amount accurately and quickly by monitoring pump speed fluctuations and pressure changes, allowing for precise refueling during unstable operation phases, reducing noise and dwell time in unstable states.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of time

If rapid water intake is used to quickly determine the needed water amount, then water intake time is reduced, but computational effort increases significantly

Engineering Contradiction:
Improvewater intake timeVSAvoidcomputational effort
Core Design Contradiction:
Loss of timeVSDevice complexity

Solution Approach 1:

The patent applies preliminary action by pre-calculating and storing the relationship between pump speed fluctuations and corresponding water amounts in a lookup table during system initialization. During operation, the controller simply queries this pre-computed table based on observed pump speed variations, avoiding complex real-time calculations while achieving rapid water intake determination

Inventive Principle:
Principle #10Preliminary action

2Productivity

If the circulating pump speed is rapidly regulated to full-load operation during water intake, then water intake speed increases, but system stability decreases making correction of instabilities difficult

Engineering Contradiction:
Improvewater intake speedVSAvoidsystem stability
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent applies dynamics by implementing a multi-stage speed regulation strategy where the pump speed is increased in controlled increments rather than immediately to full load. The controller monitors pump stability at each stage and adjusts the water intake rate dynamically, allowing the system to adapt to changing conditions while maintaining stability even during rapid water intake

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent applies feedback by continuously monitoring pump operating parameters (current, speed, pressure) during water intake and using this information to adjust the water flow rate in real-time. This closed-loop control enables the system to detect and correct instabilities such as air bubbles or supply interruptions while maintaining high water intake speed

Inventive Principle:
Principle #23Feedback

3Reliability

If discrete refueling cycles are used to handle unstable pump operation, then pump stability is restored, but water consumption increases due to multiple refueling steps

Engineering Contradiction:
Improvepump operation stabilityVSAvoidwater consumption
Core Design Contradiction:
ReliabilityVSLoss of substance

Solution Approach 1:

The patent replaces the mechanical/discrete refueling approach with an electronic control system that continuously monitors pump speed fluctuations and calculates the precise water amount needed based on observed variations. This substitution of continuous electronic control for discrete mechanical refueling reduces the number of refueling cycles and optimizes water consumption while maintaining pump stability

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

4Productivity

If the circulating pump is operated at target speed during water intake, then water intake efficiency improves, but pump operation becomes unstable causing noise and extended unstable phases

Engineering Contradiction:
Improvewater intake efficiencyVSAvoidnoise
Core Design Contradiction:
ProductivityVSObject-generated harmful factors

Solution Approach 1:

The patent applies parameter changes by dynamically adjusting the pump speed parameter during water intake based on the stage of filling and water level conditions. The controller modifies operational parameters (speed, flow rate) in real-time to maintain efficient water intake while avoiding the noise and instability associated with operating at constant target speed during the entire intake process

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 method ensures the most accurate and rapid determination of water intake, significantly reducing noise and computational effort while maintaining stable pump operation, even with varying loads, by using speed-controlled circulation pumps and statistical calculations to determine refueling amounts based on pump speed variations.

Implementation Method 1

a circulating pump whose speed can be regulated

Methodology Applied
Scientific EffectPump: Pump

Implementation Method 2

the drive of the pump impeller... is effected by a motor

Methodology Applied
Scientific EffectMechanical Force: Mechanical Force

Implementation Method 3

The circulating pump has three separate pressure ports which are connected to the respective spray arm via spray arm feed lines

Methodology Applied
Scientific EffectPressure Gradient: Pressure Gradient

Implementation Method 4

the spray arm... is supplied with washing or cleaning liquid via the pressure connection

Methodology Applied
Scientific EffectFluid Spray: Fluid Spray

Data Source

PatentEP1967121B1Method for causing water to flow into the detergent holder of a dishwasher
Publication Date: 2011.07.06 MIELE & CO KG
  • EP1967121B1 patent drawingFigure 1~2
  • EP1967121B1 patent drawingFigure 3A~3F

AI summary

The method involves filling a ground water amount and increasing a rotational speed of a circulating pump (5) from a starting rotational speed to a target rotational speed. The rotational speed of the circulating pump is increased to a refueling rotational speed based on the starting rotational speed after the intake of the ground water amount such that an unstable pump run occurs. The water amount is supplied to a rinsing machine i.e. dishwasher (1), depending on the refueling rotational speed or a mathematical relationship between the target rotational speed and refueling rotational speed.