Plugged Honeycomb Structure for Diesel Particulate Filter

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Conventional plugged honeycomb structures for diesel particulate filters face issues with mechanical strength, thermal shock resistance, and PM trapping efficiency due to excessive reinforcing portions, leading to increased pressure loss and reduced open area, which complicates crack prevention and soot deposition management.

Innovation Solution

A plugged honeycomb structure design with specific classification and distribution of intersection portions, where 30% or more of first specific intersection portions and 30% or more of non-first specific intersection portions are optimized to maintain mechanical strength and thermal shock resistance, inhibiting crack growth and pressure loss while preserving PM trapping efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If reinforcing portions are arranged in all corners of the cells, then mechanical strength is improved, but open area of inflow side end face decreases and pressure loss increases

Engineering Contradiction:

Improvemechanical strengthVSAvoidopen area of inflow side end face

Core Design Contradiction:

StrengthVSArea of stationary object

Solution Approach 1:

The patent applies local quality by selectively arranging reinforcing portions only in specific corners of cells (first corners) rather than all corners. This creates a non-uniform distribution where reinforcement is concentrated in locations most critical for preventing crack propagation during thermal shock, while leaving other corners without reinforcing portions to preserve open area and reduce pressure loss.

Inventive Principle:

Principle #3Local quality

2Strength

If reinforcing portions are arranged in all corners of the cells, then mechanical strength is improved, but volume of inflow cells decreases and storing capacity to deposit ash decreases

Engineering Contradiction:

Improvemechanical strengthVSAvoidvolume of inflow cells

Core Design Contradiction:

StrengthVSVolume of stationary object

Solution Approach 1:

The patent uses local quality by placing reinforcing portions only in specific first corners of cells rather than all corners. This selective reinforcement approach maintains mechanical strength where most needed for crack prevention while preserving cell volume in other regions, thereby maintaining storing capacity for ash deposition.

Inventive Principle:

Principle #3Local quality

3Area of stationary object

If number of reinforcing portions is reduced, then open area and volume are preserved, but resistance to thermal stress and crack prevention capability deteriorates

Engineering Contradiction:

Improveopen area of inflow side end faceVSAvoidresistance to thermal stress

Core Design Contradiction:

Area of stationary objectVSReliability

Solution Approach 1:

The patent applies local quality by strategically placing reinforcing portions in specific first corners that are most susceptible to crack initiation and propagation during thermal shock. This targeted approach provides maximum thermal stress resistance with minimum reinforcing portions, preserving open area while maintaining reliability.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent uses preliminary action by pre-positioning reinforcing portions in critical corners before thermal shock occurs. These reinforcing portions are specifically designed to intercept and stop crack propagation at the corners during subsequent thermal shock events, providing advance protection against the most vulnerable points in the structure.

Inventive Principle:

Principle #10Preliminary 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 optimized structure effectively inhibits the decrease of open area, increase of pressure loss, and deterioration of PM trapping efficiency, ensuring excellent mechanical strength and thermal shock resistance, even when cracks form, thereby preventing soot leakage and maintaining filtration efficiency.

Implementation Method 1

the porous partition walls trap and filter the PM

Methodology Applied

Scientific EffectPhysical filtration: Filter (physical)

Implementation Method 2

reinforcing portions constituted of R-parts or the like are selectively disposed in corners of the cells defined by the partition walls

Methodology Applied

Scientific EffectMechanical reinforcement:

Data Source

PatentUS10232300B2Plugged honeycomb structure

Publication Date: 2019.03.19 NGK INSULATORS LTD

AI summary

In the plugged honeycomb structure, 30% or more of first intersection portions in which a first partition wall intersects a second partition wall are first specific intersection portions in which a diameter of a maximum inscribed circle drawn in the first intersection portion is a specific size for a shortest distance between an inflow cell and an outflow cell, and 30% or more of non-first intersection portions other than the first intersection portions are non-first specific intersection portions in which a diameter of a maximum inscribed circle drawn in a non-first intersection portion is a specific size for a shortest distance between the inflow cells or the outflow cells.