Variable Muffler Valve Layout for Low-Noise Exhaust Control
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Solution Overview
Problem
Existing vehicle mufflers with variable valves suffer from noise generation due to valve plate vibrations and impacts, which are exacerbated by the use of expensive and heavy torsion springs for corrosion resistance, increasing manufacturing costs and weight.
Innovation Solution
A muffler design featuring a rotatable valve plate with a lug and guide projection, mounted on a baffle through a shaft, and a valve actuator with a spring, allowing the valve plate to maintain contact with the baffle during operation, eliminating the need for shock absorbing materials and reducing manufacturing costs by using a coil spring as the biasing element.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a torsion spring is used as a biasing element in the variable valve, then corrosion resistance and reliability are improved, but weight and manufacturing cost increase
Solution Approach 1:
The patent replaces the expensive torsion spring with a cheaper coil spring that achieves sufficient performance for the application. The coil spring provides the necessary biasing force while being less expensive and lighter, accepting that it may have shorter service life but delivering adequate reliability for exhaust valve operation.
Solution Approach 2:
The patent changes the spring type from torsion spring to coil spring, altering the mechanical parameters of the biasing element. This parameter change reduces weight and cost while maintaining the essential function of providing biasing force to the valve plate, though with different mechanical characteristics.
2Object-generated harmful factors
If a shock absorbing material is interposed between the valve plate and valve body, then noise from valve plate vibrations and contact impacts is reduced, but device complexity and manufacturing cost increase
Solution Approach 1:
The patent removes the shock absorbing material from the variable valve assembly, extracting the harmful element that caused noise. By eliminating this additional component, the design achieves noise reduction through simpler means - the valve plate maintains direct contact with the valve body without intermediate shock absorbing materials, thereby reducing device complexity and manufacturing cost while still managing noise through the valve mechanism design itself.
3Reliability
If a torsion spring is used as a biasing element, then the valve plate can be biased toward closed position, but manufacturing difficulty and cost increase
Solution Approach 1:
The patent replaces the difficult-to-manufacture torsion spring with a easier-to-manufacture coil spring. The coil spring is simpler to produce, less expensive, and achieves the necessary biasing function, thereby improving ease of manufacture while maintaining the essential biasing reliability needed for valve operation.
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 minimizes noise from valve plate vibrations and impacts, reduces manufacturing costs, and lightens the muffler by eliminating the need for expensive materials like INCONEL, while maintaining efficient exhaust gas management.
Implementation Method 1
a coil spring (27) instead of a torsion spring. The coil spring (27) may be elastically supporting the valve plate (21) to bias the valve plate (21) toward a closed position
Implementation Method 2
a valve actuator (25) moving the valve arm (22) by variations in pressure of the exhaust gas
Data Source
AI summary
A muffler for a vehicle includes: a muffler shell; a baffle disposed within the muffler shell, and having a first opening and a second opening which allow an exhaust gas to pass therethrough; and a variable valve mounted on the baffle. In particular, the variable valve includes: a valve plate rotatably mounted to open and close the first opening of the baffle; a valve arm connected to the valve plate; and a valve actuator to move the valve arm by variations in pressure of the exhaust gas. The valve plate is capable of rotating in a plane parallel to a plane of the baffle.