Dishwasher Valve With Sharp-Edged Seat to Sever Dirt Particles

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Solution Overview

Problem

Dishwashers face issues with valve clogging due to dirt particles in the liquid line, which can impair the sealing function and lead to operational malfunctions, especially in dirty water environments.

Innovation Solution

The valve seat and valve element are designed with a substantially sharp-edged tear-off edge, allowing dirt particles to be severed during closure, and an inclined sealing surface to prevent permanent settlement, combined with a thermal actuator for enhanced cleaning and a siphon design for gravity-assisted dirt removal.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a conventional valve with smooth sealing surfaces is used, then the valve can be easily manufactured, but dirt particles accumulate in the flow gap between the valve element and valve seat, impairing the sealing function

Engineering Contradiction:
Improvesealing functionVSAvoidvalve structure
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The valve seat is designed with a localized sharp-edged tear-off edge at the sealing contact point, while the rest of the valve structure maintains conventional smooth surfaces. This localized geometric feature enables dirt particle severing without requiring complex manufacturing throughout the entire valve assembly.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The sharp-edged tear-off edge, which could potentially cause operational damage, is instead utilized to sever and remove dirt particles during valve closure. The closing action that would normally press dirt into the sealing surface is converted into a beneficial cutting action that eliminates the contaminants.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

2Reliability

If the valve seat is designed with sharp edges to sever dirt particles, then dirt particles can be cut off during closing, but operational damage to the sealing surface may occur

Engineering Contradiction:
Improvedirt particle removalVSAvoidsealing surface integrity
Core Design Contradiction:
ReliabilityVSStrength

Solution Approach 1:

The sealing surface is designed with a localized rounded tip at the tear-off edge, while the rest of the sealing surface maintains the sharp geometry needed for dirt particle severing. This localized rounding prevents stress concentration and operational damage without compromising the cutting function.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The rounded tip at the tear-off edge acts as a pre-designed protective feature that prevents damage before it can occur during valve operation. This geometric cushioning ensures that the sharp edges can sever dirt particles without risking damage to the sealing surface during repeated closing cycles.

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

3Reliability

If the sealing surface is aligned horizontally, then the valve structure is simple, but dirt particles can permanently settle in the flow gap between the valve element and valve seat

Engineering Contradiction:
Improveprevention of dirt settlementVSAvoidsealing surface orientation
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The sealing surface is deliberately designed with an asymmetric inclination relative to the horizontal plane, creating a tilted sealing surface that prevents dirt particle accumulation. This asymmetric geometry causes dirt particles to be carried away by gravity and liquid flow rather than settling in the flow gap.

Inventive Principle:
Principle #4Asymmetry

4Adaptability or versatility

If an adjustable valve element is used to control liquid flow, then the valve can regulate flow rate, but dirt particles in the liquid can block the valve and impair operation

Engineering Contradiction:
Improveflow control capabilityVSAvoidvalve operation
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The adjustable valve element's movement during opening and closing operations is converted into a beneficial dirt particle severing action. The same motion that controls liquid flow also presses the valve element against the sharp-edged valve seat to cut off and remove dirt particles, transforming the potential harm of dirt accumulation into a self-cleaning mechanism.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

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 design ensures reliable valve operation by preventing dirt accumulation, maintaining the sealing function, and facilitating easy cleaning, thus reducing the risk of malfunctions and leaks in dirty water environments.

Implementation Method 1

the use of a thermal actuator is preferred, in which an expandable material, such as wax, is expanded when energized, as a result of which particularly large actuating forces can be achieved

Methodology Applied
Scientific EffectThermal expansion: Thermal Expansion

Implementation Method 2

a siphon design for gravity-assisted dirt removal

Methodology Applied
Scientific EffectGravity: Gravitation

Data Source

PatentEP2461732B1Water-bearing domestic appliance
Publication Date: 2019.09.11 BSH HAUSGERATE GMBH
  • EP2461732B1 patent drawingFigure 1
  • EP2461732B1 patent drawingFigure 2
  • EP2461732B1 patent drawingFigure 3

AI summary

The invention relates to a water-bearing domestic appliance, in particular a dishwasher, having a liquid line (23) in which a valve (26) is arranged, said valve having an adjustable valve element (45) which interacts with a valve seat (49) in order to open and close the valve (26). According to the invention, the valve seat (49) or the valve element (45) is designed, at least partially, to have a substantially sharp-edged severing edge with which particles (61) of dirt between the valve seat (49) and the valve element (45) can be cut off during a closing process of the valve (26).