Muffler Pipe Connection with Axial Play for Thermal Expansion
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Mufflers for internal combustion engines face challenges in reliably compensating for thermal expansions at connections between inlet/outlet pipes and inner pipes due to differing temperatures, leading to stress and potential deformation issues.
Innovation Solution
A design where the second pipe has a pipe piece that the first pipe can be plugged into, with slits and nubs for secure axial displacement and rotation prevention, allowing for thermal expansion compensation while maintaining a simple structure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If rigid inner bases are used to support pipes and separate chambers, then structural stability is improved, but thermal expansion compensation capability deteriorates
Solution Approach 1:
The connection between pipes is segmented into modular components: a first pipe portion, a second pipe portion, and a coupling element with axial play. This segmentation allows each component to perform its specific function while collectively providing both structural stability and thermal expansion compensation.
Solution Approach 2:
The coupling element is designed with axial play (movability) that changes the effective length parameter of the pipe connection. This parameter change allows the connection to adapt to thermal expansion and contraction while maintaining structural integrity.
2Reliability
If pipes are rigidly connected to compensate for thermal expansion, then reliability is improved, but device complexity increases
Solution Approach 1:
The connection is divided into simple modular segments (first pipe portion, second pipe portion, coupling element) that can be manufactured and assembled independently, reducing overall complexity while maintaining reliability.
Solution Approach 2:
The coupling element provides localized flexibility only where needed for thermal expansion compensation, while the rest of the pipe structure maintains its structural rigidity. This localized approach avoids unnecessary complexity throughout the entire system.
3Strength
If sliding seats are used between pipes to reduce stresses, then stress resistance is improved, but device complexity increases
Solution Approach 1:
The invention extracts the stress-absorbing function from separate sliding seat components and integrates it directly into the coupling element's axial play mechanism. This eliminates the need for additional sliding seats while maintaining stress resistance.
Solution Approach 2:
The coupling element combines multiple functions: mechanical connection, thermal expansion compensation, and stress absorption. By merging these functions into a single component, the overall device complexity is reduced while maintaining or improving stress resistance.
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 design effectively compensates for thermal expansions, securing the first pipe against rotation and allowing limited axial displacement, thus simplifying the connection and improving noise reduction in mufflers.
Implementation Method 1
High stresses arise due to different temperatures at the jacket and at gas-conducting pipes, the stresses either having to be taken up by the inner bases by deformation or having to be reduced by sliding seats between the pipes
Implementation Method 2
The end section of the first pipe is preferably provided with slits into which nubs engage which are provided at the inner boundary of the opening of the support element
Data Source
AI summary
A muffler, in particular a rear muffler, for an exhaust gas system of an internal combustion engine, in particular a motor vehicle engine, comprises a housing, in particular a housing having a jacket and two end walls, and comprises at least one first pipe, in particular an inlet or outlet pipe which is in particular led through the jacket and which is connected to a second pipe, in particular to an inner pipe. The second pipe comprises a pipe piece into which a pipe piece of the first pipe led through an opening of an inner support element is plugged in an axially displaceable manner. In this respect, the pipe piece of the first pipe is preferably provided with slits into which nubs engage which are provided at the inner boundary of the opening of the support element. The end section of the first pipe is expanded in its region plugged into the pipe piece of the second pipe to fix the first pipe at the support element.