Overlapping Exhaust Pipe Junction for Noise Attenuation
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Solution Overview
Problem
Existing vehicle exhaust systems face challenges in effectively damping noise due to resonating frequencies, as additional components like mufflers and microperforated materials can compromise durability and are prone to failure from debris accumulation, and manufacturing limitations restrict the production of small diameter holes in thicker materials.
Innovation Solution
A vehicle exhaust system design featuring an upstream and downstream pipe configuration with an overlapping junction region that defines both a primary and secondary exhaust gas flow path, where the secondary path allows for noise attenuation without compromising durability and is less susceptible to debris plugging.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-generated harmful factors
If additional components like mufflers and resonators are incorporated into the exhaust system to attenuate resonance frequencies, then noise attenuation is improved, but device complexity and weight increase
Solution Approach 1:
The patent combines the noise attenuation function directly into the exhaust pipe wall structure by creating a multi-layer construction with sound-absorbing material integrated between the inner and outer pipes, eliminating the need for separate mufflers and resonators. This merging of functions reduces device complexity while maintaining noise attenuation performance.
Solution Approach 2:
The exhaust pipe structure is designed to perform multiple functions simultaneously: the inner pipe provides structural support and exhaust flow, the sound-absorbing material provides noise attenuation, and the outer pipe provides structural support and protection. This multi-functionality eliminates the need for separate dedicated noise control components.
2Object-generated harmful factors
If microperforated material is used to dampen noise while allowing sound waves to exit, then noise attenuation is improved, but durability deteriorates due to thin material and structural weakness
Solution Approach 1:
The patent uses a composite structure consisting of an inner pipe, sound-absorbing material, and outer pipe. This composite construction provides both the noise attenuation properties needed and the structural strength required, overcoming the weakness of thin microperforated materials by embedding them within a robust multi-layer system that distributes mechanical stresses.
3Object-generated harmful factors
If relatively larger holes are cut into the exhaust pipe to allow sound waves to exit, then noise attenuation is improved, but durability deteriorates due to weakened pipe structure
Solution Approach 1:
The patent nests the sound-absorbing material between the inner and outer pipes, creating a layered configuration where the sound-absorbing material is protected by the outer pipe while the inner pipe maintains structural integrity. This nesting allows effective noise attenuation without compromising the strength of individual pipe components.
4Manufacturing precision
If conventional manufacturing methods are used to produce small diameter holes, then manufacturing precision is limited, but component thickness must be limited to 1 mm which compromises durability
Solution Approach 1:
The patent changes the approach from creating small holes in thin material to using a multi-layer construction where sound absorption occurs through the sound-absorbing material layer. This parameter change allows the use of thicker, more durable components while achieving effective noise attenuation through the layered structure rather than relying on small hole precision.
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 attenuates noise while maintaining structural integrity and reducing the risk of debris-induced failures, offering a more durable and efficient noise reduction solution compared to traditional methods.
Implementation Method 1
A sound-absorbing material is positioned within the exhaust system downstream of the exhaust component
Implementation Method 2
The sound-absorbing material may be positioned within the exhaust system downstream of the exhaust component and upstream of a vehicle turbine
Implementation Method 3
as a result of resonating frequencies, the components may generate undesirable noise
Data Source
AI summary
A vehicle exhaust system for allowing passage of exhaust gasses therethrough. The vehicle exhaust system has a first pipe having a first end and a second end. The first end defines an exhaust gas inlet and the second end defines an exhaust gas outlet. The vehicle exhaust system also has a second pipe positioned downstream of the first pipe and has a third end and a fourth end. At least a portion of the second end of first pipe is positioned within the third end of the second pipe defining an overlap between the second end of the first pipe and the third end of the second pipe. The first pipe and the second pipe together define a volume for the exhaust gasses. The volume comprises a first volume passageway between the exhaust gas inlet and the exhaust gas outlet and a second volume passageway defined by the overlap of the second pipe and the first pipe and having an inlet for exhaust gasses into the second volume passageway and an outlet from the second volume passageway positioned axially upstream of inlet. The inlet is positioned downstream of the exhaust gas outlet