Cleaning device with flow diverting element with mode filter and use of a flow diverting element with mode filter

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Solution Overview

Problem

Existing cleaning devices face challenges in achieving effective sound attenuation while maintaining high flow efficiency, particularly in the propagation of transverse modes of sound through flow deflection elements.

Innovation Solution

The implementation of a mode filter device on the flow deflection element, specifically positioned on the second tube arm, to suppress transverse modes of sound propagation, combined with geometric configurations and sound absorption materials to enhance sound attenuation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If a flow deflection element is used to direct airflow, then flow efficiency is improved, but transverse modes of sound propagation are generated causing noise

Engineering Contradiction:
Improveflow efficiencyVSAvoidtransverse modes of sound
Core Design Contradiction:
ProductivityVSObject-generated harmful factors

Solution Approach 1:

A mode filter is introduced as an intermediary component in the second tube arm to suppress transverse modes of sound propagation. The mode filter acts as a mediator that allows the flow deflection element to maintain its flow efficiency while independently addressing the noise problem generated by transverse modes.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The sound attenuation function is extracted from the flow deflection element itself and implemented as a separate mode filter component. This allows the flow deflection element to focus on directing airflow efficiently while the mode filter specifically targets and suppresses transverse modes of sound propagation in the second tube arm.

Inventive Principle:
Principle #2Taking out (Extraction)

2Object-generated harmful factors

If sound attenuation measures are implemented, then noise is reduced, but flow efficiency may be compromised

Engineering Contradiction:
Improvesound attenuationVSAvoidflow efficiency
Core Design Contradiction:
Object-generated harmful factorsVSProductivity

Solution Approach 1:

The mode filter is positioned specifically in the second tube arm where transverse modes are generated, applying sound attenuation locally rather than throughout the entire flow path. This localized approach ensures noise reduction while minimizing impact on overall flow efficiency.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The air guidance device is segmented into a first tube arm for airflow intake and a second tube arm for exhaust, with the mode filter applied only to the second tube arm. This segmentation allows sound attenuation to be applied selectively without compromising the flow efficiency of the entire system.

Inventive Principle:
Principle #1Segmentation

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 results in effective sound attenuation with minimal impact on airflow, achieving high transmission loss and maintaining efficient airflow rates.

Implementation Method 1

at least one mode filter which is positioned on the second tube arm... for transverse modes of sound propagation

Methodology Applied
Scientific EffectSound absorption: Acoustic Absorption

Data Source

PatentEP4422467B1Cleaning device with flow diverting element with mode filter and use of a flow diverting element with mode filter
Publication Date: 2026.01.21 ALFRED KARCHER SE & CO KG
  • EP4422467B1 patent drawingFigure 1
  • EP4422467B1 patent drawingFigure 2~3
  • EP4422467B1 patent drawingFigure 4(1)~4(3)

AI summary

Provided is a cleaning device comprising at least one noise source and an air conducting unit having at least one flow deflection element (10), the at least one flow deflection element (10) having a first pipe arm (16) and a second pipe arm (18), the second pipe arm (18) extending transversely to the first pipe arm (16), sound propagating from the first pipe arm (16) into the second pipe arm (18) during operation of the cleaning device, characterized in that a mode filtering unit (72) for transverse modes of sound propagation is arranged on the at least one flow deflection element (10), the mode filtering unit (72) comprising at least one mode filter (74; 84; 90) that is positioned on the second pipe arm (18).