Household appliance with conversion valve

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Solution Overview

Problem

Tumble dryers with heat pumps face inefficiencies due to fluff accumulation on heat exchanger fins, leading to complex designs and residue formation, limiting flexibility in appliance positioning and effective cleaning.

Innovation Solution

A directional control valve with a hollow-cylindrical housing and rotatable switch body, featuring a filter cavity that reverses flow direction between inlets and outlets, allowing for pressurized connections and flexible cleaning, eliminating the need for a downpipe and enabling efficient lint removal.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If a downpipe is used to flush condensed water onto the lamellar structure, then the heat exchanger can be cleaned, but the appliance design becomes complex and positioning is limited

Engineering Contradiction:
Improveappliance design simplicityVSAvoidpositioning flexibility
Core Design Contradiction:
Ease of manufactureVSAdaptability or versatility

Solution Approach 1:

The patent inverts the traditional top-to-bottom flushing approach by enabling bidirectional flow through the directional control valve. The valve can reverse the flow direction to flush from bottom to top, eliminating the need for a vertical downpipe and allowing flexible positioning of the washing compartment relative to the heat exchanger.

Inventive Principle:
Principle #13The other way round (Inversion)

Solution Approach 2:

The directional control valve provides dynamic flow control by switching between different operating positions. This dynamic capability allows the system to adapt the flushing direction based on the relative positions of components, enabling both simplified design and positioning flexibility without compromise.

Inventive Principle:
Principle #15Dynamics

2Ease of operation

If fluff is flushed from top to bottom through the lamellar structure, then cleaning occurs, but permanent residues form in some places

Engineering Contradiction:
Improvecleaning effectivenessVSAvoidfluff residue formation
Core Design Contradiction:
Ease of operationVSObject-generated harmful factors

Solution Approach 1:

The system employs periodic flushing cycles with alternating directions. The directional control valve switches between first and second operating positions to flush from top to bottom and then from bottom to top, preventing permanent residue formation by periodically reversing the flow direction to dislodge and remove accumulated fluff.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

By enabling reverse flow direction through the directional control valve, the system flushes from bottom to top in alternating cycles, which prevents fluff from becoming permanently lodged in the lamellar structure by periodically reversing the flushing direction.

Inventive Principle:
Principle #13The other way round (Inversion)

3Ease of operation

If a filter is positioned at the entrance to the rinsing tank, then fluff is filtered out, but the filter requires removal and cleaning by the user

Engineering Contradiction:
Improvefiltering performanceVSAvoidfilter maintenance complexity
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The filter is integrated into the bidirectional flushing system and is automatically cleaned by the reversed flow. When the directional control valve switches to the second operating position, condensed water flows through the filter from the opposite direction, automatically removing accumulated fluff and eliminating the need for manual filter removal and cleaning.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The filter undergoes periodic automatic cleaning through the bidirectional flushing mechanism. The directional control valve alternates between filtering mode and reverse-flushing mode, where the reversed flow periodically cleans the filter by flushing accumulated fluff back through the system, reducing maintenance requirements.

Inventive Principle:
Principle #19Periodic 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 provides a compact, robust, and cost-effective means to establish and break pressurized connections between appliance components, facilitating improved cleaning performance and flexible positioning by reversing flow direction to remove lint and impurities effectively.

Implementation Method 1

reversing flow direction between inlets and outlets

Methodology Applied
Scientific EffectFluid flow reversal:

Implementation Method 2

a filter extending between the first channel opening and the second channel opening

Methodology Applied
Scientific EffectFiltration: Filter (physical)

Implementation Method 3

switching body has a first operating position and a second operating position, and in the first operating position a connection between the first inlet and the first outlet is established

Methodology Applied
Scientific EffectMechanical valve actuation: Valve

Data Source

PatentEP3041983B1Household appliance with conversion valve
Publication Date: 2017.10.11 BSH HAUSGERATE GMBH
  • EP3041983B1 patent drawingFigure 1
  • EP3041983B1 patent drawingFigure 2
  • EP3041983B1 patent drawingFigure 3

AI summary

The invention relates to a directional control valve (1) for a domestic appliance (W), comprising at least: a housing (2), which has a first inlet (3), a second inlet (4), a first outlet (5), and a second outlet (6); and a switching element (11) movably accommodated in the housing (2), which switching element (11) has a connecting channel (12, 14, 15), which extends through the switching element and which has a first channel opening (14) and a second channel opening (15), which connecting channel (12, 14, 15) has a cavity (12), in which cavity at least one filter (16) extending between the first channel opening (14) and the second channel opening (15) is accommodated, wherein the switching element (11) has a first operating position and a second operating position and a connection is established between the first inlet (3) and the first outlet (5) and a connection between the second inlet (4) and the second outlet (6) is ended in the first operating position and a connection is established between the second inlet (4) and the second outlet (6) and a connection between the first inlet (2) and the first outlet (5) is ended in the second operating position. A domestic appliance (W) according to the invention has at least one directional control valve (1).