Aftertreatment Assembly Tolerance Compensation Using Variable Pipe Joints
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Solution Overview
Problem
Existing aftertreatment systems for internal combustion engines face challenges in compact design and cost-effectiveness due to the need for elastic bellows to compensate for mounting and manufacturing tolerances, which can be costly and space-consuming, especially when multiple aftertreatment components are involved.
Innovation Solution
The use of variable pipe joints, specifically adjustable spherical and slip pipe joints, allows for positional and orientational displacement compensation between the exhaust outlet and inlet of the aftertreatment assembly, enabling flexible and cost-efficient assembly and mounting of aftertreatment components relative to their mounting structure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If elastic bellows are used to compensate for mounting and manufacturing tolerances, then the aftertreatment assembly can accommodate positional and orientational displacements, but the cost and space requirements increase significantly
Solution Approach 1:
The pipe connection is divided into multiple sections with adjustable joints between them. The spherical pipe joint allows angular adjustment while the slip pipe joint allows axial length adjustment, segmenting the tolerance compensation function into discrete adjustable components rather than requiring a single complex elastic bellows assembly
Solution Approach 2:
The pipe connection system transitions from a fixed rigid structure to a dynamically adjustable configuration. The spherical and slip pipe joints enable the connection to adapt its geometry during assembly, allowing positional and orientational displacement compensation through mechanical adjustment rather than elastic deformation
2Reliability
If multiple aftertreatment components are assembled with precise mounting positions, then emissions treatment effectiveness is maintained, but the assembly complexity and time increase
Solution Approach 1:
The spherical and slip pipe joints are pre-configured with adjustment capabilities built into the connection design. This preliminary preparation of adjustment mechanisms allows for quick field adjustments without requiring complex assembly procedures or specialized tools, thereby maintaining assembly productivity while ensuring proper positioning for emissions treatment effectiveness
3Manufacturing precision
If fixed pipe connections are used between exhaust outlet and aftertreatment component, then manufacturing precision is maintained, but adaptability to different engine configurations is reduced
Solution Approach 1:
The pipe connection system incorporates adjustable parameters through the spherical joint (angular orientation) and slip joint (axial length). These parameter changes allow the same manufactured components to adapt to different engine configurations and tolerances while maintaining precise fluid connection, eliminating the need for custom-manufactured rigid connections for each configuration
Data Source
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AI summary
An aftertreatment assembly (14) for an internal combustion engine (10) is disclosed. The assembly (14) includes an aftertreatment component (16) with an inlet (68), and a pipe connection (26) fluidly connected to the inlet (68). The pipe connection (26) includes an adjustable spherical pipe joint (66) that joins two angularly offset pipe sections (202, 204), and a slip pipe joint (62) that joins two axially aligned pipe sections (102, 104) and that can adjust a combined length of the two axially aligned pipe sections (102, 104). The assembly (14) allows for compensating the positional and orientational displacements between an exhaust outlet and the inlet of the aftertreatment assembly (14).