Exhaust Valve Half-Body Structure for Gas-Tight Flat Shutter Sealing
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Solution Overview
Problem
Existing driver-operated exhaust valves for automobile combustion engines are costly due to the use of multiple parts and require precise machining, leading to inadequate gas tightness and increased mass, which is not competitive in the automotive market demanding reduced cost and mass while addressing pollutant emissions.
Innovation Solution
A simplified design using two identical half-bodies forming the valve body with radially offset axes and collars creating coplanar seats for a flat shutter contact, reducing the number of parts and manufacturing complexity, and utilizing stamped or cut metal sheets for production.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If three parts (cylindrical body, two sleeves) are used to form the valve body with beveled edges on the shutter, then the valve can close the exhaust gas circulation passage, but the cost increases due to multiple parts and precise machining
Solution Approach 1:
The patent merges the cylindrical body and two sleeves into a single integrated valve body structure. The collar is formed as one piece with the tubular part, eliminating the need for separate sleeves and reducing the total part count from three to one, while maintaining the gas tightness function through the coplanar bearing surfaces.
2Reliability
If beveled edges are machined on the shutter to contact the seats, then the exhaust gas circulation passage can be closed, but the manufacturing cost increases due to precise machining requirements
Solution Approach 1:
Instead of machining beveled edges on the shutter to contact the seats, the patent inverts the approach by creating coplanar bearing surfaces on the collar that contact the flat sides of the shutter. This reversal of the contact geometry eliminates the need for complex beveled edge machining while maintaining effective gas sealing.
3Reliability
If the seat width is limited to the sleeve wall thickness, then the valve structure is compact, but the contact surface between stop and shutter is insufficient reducing seal effectiveness
Solution Approach 1:
The patent transitions from a linear contact geometry (beveled edges) to a planar contact geometry (coplanar bearing surfaces). By creating bearing surfaces that extend in multiple dimensions on the collar, the contact surface area between the stop and shutter is significantly increased, enhancing seal effectiveness without increasing overall valve size.
4Ease of manufacture
If a flat seal is added with two metal plates fixed by welding or screwing to form the shutter, then the valve body can be constructed, but the cost increases due to four parts and assembly requirements
Solution Approach 1:
The patent merges the collar and tubular part into a single integrated component formed from one piece of metal. This eliminates the need for separate metal plates and welding or screwing operations, reducing the part count from four to one while maintaining manufacturing feasibility through stamping or cutting processes.
5Temperature
If the seal is subjected to high exhaust gas temperatures up to 850°C, then the valve functions in automotive conditions, but the seal deforms reducing tightness to zero
Solution Approach 1:
The patent eliminates the vulnerable seal component entirely and replaces it with a robust metal-to-metal contact system using coplanar bearing surfaces on the collar. This disposable-like approach uses the inherent thermal stability of metal materials to withstand high exhaust temperatures without deformation, ensuring continuous gas tightness in automotive conditions.
Data Source
AI summary
An automobile exhaust valve is provided, in particular for an automobile combustion engine and more particularly for an embodiment of an implementation of a gas passage shutter. A valve body defines a gas circulation passage along a longitudinal axis and is composed of only two identical half-bodies whose axes, parallel to the longitudinal axis, are offset radially, in order to define inside the valve body two seats on which sides of the gas passage shutter come into flat contact in a closed position. An exhaust pipe equipped with such a valve, and a vehicle equipped with such an exhaust pipe, are also provided.