Honeycomb Body Brazed Zone Design for Thermal Expansion
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Large honeycomb bodies with unfavorable diameter/length ratios often experience connection failures between metallic layers and housing, leading to detachment and component failure under thermal and dynamic loads, particularly in exhaust-gas treatment components of mobile internal combustion engines.
Innovation Solution
A honeycomb body design featuring a belt-shaped brazing material-free region at the end sides with multiple brazed zones, ensuring a strong and flexible connection by maintaining a large inner volume and using brazing material connections that form between the metallic layers and housing, primarily in the central region, with a brazing material-free region width of less than 10% of the extent.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If the entire honeycomb body is brazed to the housing, then the connection strength is improved, but the thermal expansion compensation capability deteriorates
Solution Approach 1:
The housing end surface is divided into a brazed zone and a non-brazed zone, creating spatially distributed brazed partial regions. This segmentation allows different regions to serve different functions: the brazed zones provide strong mechanical connection while the non-brazed zones allow thermal expansion compensation.
Solution Approach 2:
Different regions of the housing end surface are given different properties: the brazed zone has strong mechanical bonding to the metallic layer, while the non-brazed zone maintains thermal expansion flexibility. This local differentiation resolves the contradiction between connection strength and thermal expansion compensation.
2Stability of the object's composition
If only partial regions are brazed to compensate thermal expansion, then the thermal expansion compensation is improved, but the connection reliability deteriorates
Solution Approach 1:
The brazed pattern is segmented into multiple distributed brazed zones rather than a single continuous brazed region. This segmentation creates multiple load paths and prevents stress concentration, improving connection reliability while maintaining thermal expansion compensation capability.
Solution Approach 2:
The non-brazed zone acts as an intermediary region between fully brazed areas, allowing controlled thermal expansion while the distributed brazed zones provide sufficient mechanical support. This intermediary zone prevents direct stress transmission that would cause connection failure.
3Volume of moving object
If the honeycomb body has a large diameter and short length, then the inner volume is improved, but the connection stability deteriorates
Solution Approach 1:
The brazed zones extend axially into the honeycomb body at the end surfaces, utilizing the axial dimension to create stable connections. This axial extension of brazed zones into the honeycomb structure provides anchoring effect that compensates for the short axial length, maintaining connection stability while preserving large inner volume.
Solution Approach 2:
The end regions of the honeycomb body are given different properties from the central region: the end regions contain brazed zones with enhanced mechanical connection, while the central region maintains open channels for exhaust flow. This local differentiation ensures connection stability at critical locations without compromising overall inner volume.
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 design effectively prevents connection failures and ensures durability under high thermal and dynamic loads by maintaining a strong and flexible connection, even in components with large diameters and short lengths, as proven in durability tests at lower exhaust gas flow speeds.
Implementation Method 1
the honeycomb body is brazed at least at one end side within one zone
Implementation Method 2
brazing material connections are formed between the metallic layers and housing
Data Source
AI summary
A honeycomb body includes two opposite end sides, at least one housing and at least one metallic layer forming channels. At least one of the end sides has at least one brazed zone forming a belt-shaped, brazing material-free zone adjacent the housing. A method for producing the honeycomb body, an exhaust-gas treatment component for an internal combustion engine and a motor vehicle having the honeycomb body, are also provided.