Intake Valve Bore Vacuum Suction Limits Flow Separation
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Solution Overview
Problem
Flow separation and backflow in the intake air delivery system of internal combustion engines, caused by deflection of intake air by the valve seat edge, lead to reduced effective valve gap area and engine performance.
Innovation Solution
Incorporating a bore in the valve seat ring with fluid communication to a conduit connected to a vacuum source, providing suction pressure to the valve gap adjacent to the valve seat ring to limit flow separation and backflow, thereby increasing the effective area of the valve gap.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the valve lift is increased to improve engine performance, then the intake air flow capacity is improved, but flow separation and backflow occur in the valve gap resulting in reduced effective area
Solution Approach 1:
A bore is provided in the valve seat ring that acts as an intermediary passage. This bore is selectively fluidly connected to the valve gap and communicates with a vacuum source, introducing a mediating suction pressure field that prevents flow separation and maintains effective flow area during high valve lift conditions
Solution Approach 2:
The invention applies pneumatic principles by introducing a vacuum suction pressure through the bore into the valve gap. This pneumatic pressure field modifies the flow characteristics of intake air, preventing turbulence and backflow that would otherwise occur at higher valve lifts, thereby maintaining reliable effective flow area
2Reliability
If the valve seat edge is used to seal the valve gap when closed, then sealing reliability is improved, but flow separation occurs at the valve seat edge during valve opening
Solution Approach 1:
The bore serves as an intermediary structure that bridges the valve seat ring and the vacuum source. It selectively connects to the valve gap during operation, introducing a controlling suction pressure that prevents the valve seat edge from generating harmful flow separation, while maintaining the edge's sealing function when closed
Solution Approach 2:
The invention changes the pressure parameter within the valve gap by introducing vacuum suction pressure through the bore. This parameter change modifies the flow regime from turbulent with backflow to laminar flow, eliminating the harmful effects generated by the valve seat edge while preserving its sealing capability
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 solution enhances intake air flow and engine performance by maintaining a larger effective valve gap area even at higher valve lifts, reducing turbulence and backflow, and can be implemented using existing engine components like turbochargers or superchargers with minimal modifications.
Implementation Method 1
Each of the conduit and the at least one bore is adapted to provide a suction pressure of the vacuum pump to a portion of the valve gap adjacent to the valve seat ring
Implementation Method 2
During a relatively higher valve lift, a flow separation may form in the intake air or the charge air mixture flowing through the valve gap
Data Source
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AI summary
An intake air delivery system (400) for an engine (100) includes a valve seat ring (206) and an intake valve (304). The intake valve (304) is adapted to contact the valve seat ring (206) in a closed position of the intake valve (304). The intake valve (304) is adapted to provide a valve gap (306) with respect to the valve seat ring (206) in an open position of the intake valve (304). The intake air delivery system (400) also includes at least one bore (208) provided in the valve seat ring (206). The at least one bore (208) is provided in selective fluid communication with the valve gap (306). The intake air delivery system (400) further includes a conduit (307) provided in fluid communication with the at least one bore (208) and a vacuum pump. Each of the conduit (307) and the at least one bore (208) is adapted to provide a suction pressure of the vacuum pump to a portion of the valve gap (306) adjacent to the valve seat ring (206).