Honeycomb Filter Protrusion Design for Crack Prevention

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Solution Overview

Problem

Conventional methods for manufacturing honeycomb filters often result in cracks in the partition walls during the deformation process, leading to defects in the flow passages.

Innovation Solution

The honeycomb filter design incorporates protrusion parts between partition walls to distribute stress and prevent cracking, with a manufacturing method that involves enlarging the cross-section areas of specific flow passages using a jig to crimp and close the other passages, thereby minimizing the occurrence of cracks.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the partition walls are deformed to close through holes by crimping, then the flow passages are sealed effectively, but cracks occur in the partition walls during deformation

Engineering Contradiction:
Improvesealing effectivenessVSAvoidpartition wall integrity
Core Design Contradiction:
ReliabilityVSStrength

Solution Approach 1:

The partition walls are designed with different thicknesses at different locations: thicker at the corner parts where cracks are likely to occur, and thinner at other portions to facilitate deformation. This local variation in thickness allows the partition walls to be crimped effectively while maintaining structural integrity at critical stress points, thus preventing cracks during the sealing process

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The partition walls are pre-formed with specific geometric features (corner parts with reduced thickness) before the closing operation. This preliminary design prepares the structure to undergo deformation without cracking, allowing the crimping process to proceed smoothly and achieve effective sealing without compromising partition wall integrity

Inventive Principle:
Principle #10Preliminary action

2Manufacturing precision

If the partition walls are crimped together to close flow passages, then the desired flow path configuration is achieved, but the deformation process causes cracks in the partition walls

Engineering Contradiction:
Improveflow passage configurationVSAvoidpartition wall integrity
Core Design Contradiction:
Manufacturing precisionVSReliability

Solution Approach 1:

The partition walls incorporate corner parts with locally reduced thickness at positions where deformation is required. This local thinning allows the partition walls to be crimped together to achieve the desired flow passage configuration while the thicker main body maintains structural integrity and prevents crack formation during the deformation process

Inventive Principle:
Principle #3Local quality

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 effectively reduces the occurrence of cracks in the honeycomb filter, resulting in a product with fewer defects and improved structural integrity.

Implementation Method 1

deforming the partition walls in such a way that the cross-section areas of through holes that are not to be closed are enlarged, and crimping the partition walls together on the side of through holes that are to be closed

Methodology Applied
Scientific EffectDeformation: Deformation

Data Source

PatentEP3115095B1Honeycomb filter, and method for manufacturing honeycomb filter
Publication Date: 2022.09.21 IBIDEN CO LTD
  • EP3115095B1 patent drawingFigure 1
  • EP3115095B1 patent drawingFigure 2
  • EP3115095B1 patent drawingFigure 3

AI summary

A honeycomb filter 100 comprises a columnar body including a plurality of inlet-side flow passages (first flow passages) 70Hin and a plurality of outlet-side flow passages (second flow passages) 70Hout extending in an axial direction and including partition walls W separating the adjacent flow passages. A cross-section area of each inlet-side flow passage 70Hin on one end face of the columnar body is larger than a cross-section area of each inlet-side flow passage in a central part in the axial direction, and a cross-section area of each outlet-side flow passage 70Hout is closed on the one end face. A corner part C that forms the inlet-side flow passage 70Hin and is formed between an adjacent pair of partition walls W has a protrusion part (first protrusion part) WP that protrudes toward an interior of the inlet-side flow passage 70Hin and extends in the axial direction, in a central part of at least one of the inlet-side flow passages 70Hin in the axial direction.