Segmented Edge-Band Filter Assembly for Multi-Stream Air Sealing

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Solution Overview

Problem

Existing filter arrangements struggle to effectively seal multiple air streams while maintaining ease of installation and reducing leakage, particularly in applications like vehicle air conditioning systems.

Innovation Solution

A filter arrangement with a filter housing containing compartments and a filter with continuous and segmented edge strips, where each bellows or filter element is assigned a compartment, and the bellows are designed with convex outwardly curved end folds to enhance sealing and prevent leakage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If multiple bellows are combined into a single filter with continuous edge bands, then installation speed is improved, but sealing reliability deteriorates due to leakage between bellows

Engineering Contradiction:
Improveinstallation speedVSAvoidsealing reliability
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The filter is divided into multiple independent bellows, each with its own segmented edge band that can be separately sealed to the housing. This segmentation allows each bellows to be individually sealed, preventing leakage while maintaining the integrated filter structure for quick installation.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different edge band configurations are applied to different parts of the filter: continuous edge bands connect bellows laterally for structural integrity and quick installation, while segmented edge bands are applied to the first side surfaces of each bellows for individual sealing to the housing, ensuring local sealing quality.

Inventive Principle:
Principle #3Local quality

2Reliability

If edge bands are added to bellows for sealing, then sealing performance is improved, but device complexity increases

Engineering Contradiction:
Improvesealing performanceVSAvoiddevice complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The edge bands are integrated with the bellows structure during manufacturing, combining the sealing function with the structural component. This merging reduces the number of separate parts and assembly steps, lowering device complexity while maintaining sealing performance.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The edge bands are designed to automatically seal against the housing walls when the filter is installed, utilizing the natural compression and deformation of the pleated filter medium. This self-sealing mechanism eliminates the need for additional sealing components or complex adjustment mechanisms.

Inventive Principle:
Principle #25Self-service

3Reliability

If convex outwardly curved end folds are used, then sealing at end folds is improved, but manufacturing precision requirements increase

Engineering Contradiction:
Improvesealing at end foldsVSAvoidmanufacturing precision
Core Design Contradiction:
ReliabilityVSManufacturing precision

Solution Approach 1:

The end folds are designed with a specific convex outward curvature parameter that creates sufficient contact pressure with the housing walls to ensure sealing. This parameter optimization achieves reliable sealing while accommodating normal manufacturing tolerances without requiring excessive precision.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP4424401B1Filter assembly with filter with segmented edge band
Publication Date: 2025.10.08 CARL FREUDENBERG KG
  • EP4424401B1 patent drawingFigure 1
  • EP4424401B1 patent drawingFigure 2a
  • EP4424401B1 patent drawingFigure 2b

AI summary

The invention relates to a filter (10) with at least two filter elements with bellows (1) or with at least two bellows (1), wherein the bellows (1) are made of pleated filter medium (7) and have first and second side surfaces (6.1, 6.2), wherein the filter elements or bellows (1) are provided with a continuous band (2) on their first side surfaces (6.1) and the bellows (1) are provided with a segmented edge band (3) on their second side surfaces (6.2). The invention also relates to a filter arrangement (100) with such a filter (10) and a filter housing (9). The housing has several chambers for filtering different air streams.