Gas Exchange Valve Arrangement for Supercharged Engines
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Solution Overview
Problem
Standard valve springs in supercharged internal combustion engines struggle with high charge pressures, leading to issues with valve opening and closing, as they are designed for smaller pressure differences, and modifying the cylinder head to accommodate stiffer springs is often difficult or impossible.
Innovation Solution
A gas exchange valve arrangement that uses pressurized charge air from the air intake duct to assist mechanical springs in keeping the valves closed, eliminating the need for external pressurized gas systems and robust steel springs, and allowing for normal springs to be used, with a compact design suitable for existing cylinder heads with minor modifications.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If standard valve springs are used in supercharged engines with high charge pressures, then the valve spring design remains simple and compatible with existing cylinder heads, but the intake valves tend to open due to insufficient closing force against large pressure differences
Solution Approach 1:
The patent combines the pneumatic pressure system with the mechanical valve spring system to create a hybrid valve actuation system. The pneumatic pressure from the supercharger is merged with the mechanical spring force to provide sufficient closing force on the intake valves, eliminating the need for separately stiffer springs or complex external control systems.
Solution Approach 2:
The system uses the engine's own supercharger output to provide the pneumatic assistance for valve closure. The charge air pressure that is already being generated for engine operation is redirected to assist valve closure, eliminating the need for external pressurized gas systems or additional control mechanisms.
2Strength
If stiffer valve springs are used to withstand large pressure differences, then the valves remain closed effectively, but significant modifications to the cylinder head are required to accommodate larger springs
Solution Approach 1:
Instead of relying solely on mechanical spring strength, the patent merges pneumatic pressure assistance with the existing mechanical spring system. This allows the use of standard valve springs that are compatible with existing cylinder head designs, avoiding the need for significant structural modifications to accommodate stiffer springs.
3Strength
If air springs are used to assist conventional mechanical springs, then the force required from mechanical springs is reduced, but external pressurized gas systems and control means are required
Solution Approach 1:
The system utilizes the engine's own supercharger output as the pressure source for the pneumatic assistance. The charge air that is already being compressed for engine operation is redirected to provide assistance to the valve springs, eliminating the need for external compressors, storage tanks, or complex control systems.
Solution Approach 2:
The supercharger serves dual functions: compressing air for engine intake and providing pneumatic assistance for valve closure. This multi-functionality eliminates the need for separate auxiliary systems dedicated solely to valve actuation assistance.
4Use of energy by moving object
If high charge pressures are used to achieve better fuel efficiency, then fuel efficiency improves, but the pressure difference over intake valves increases causing them to open
Solution Approach 1:
The patent converts the harmful effect of high charge air pressure (which causes intake valves to open) into a beneficial effect by using that same pressure to assist valve closure. The pneumatic system captures the pressure differential that would otherwise be problematic and redirects it to strengthen the closing force on the intake valves.
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
Prevents leakage and maintains effective valve closure even at high charge pressures, reduces the need for complex auxiliary systems, and minimizes friction and starting issues, while automatically adjusting to higher pressures without requiring additional piping or control systems.
Implementation Method 1
means for introducing pressurized charge air from an air intake duct of the engine into the chamber between the thrust means and the inner end of the chamber for assisting in keeping the gas exchange valve closed
Data Source
Figure 1
Figure 2~3
Figure 4
AI summary
A gas exchange valve arrangement for a supercharged internal combustion engine, which arrangement comprises a gas exchange valve (1) having a valve head (2) and a valve stem (3) connected to the valve head (2), the arrangement further comprising a valve spring (4) being arranged around the valve stem (3) for creating a force for closing the valve (1), a chamber (5) being arranged around the valve stem (3), and thrust means (6, 19) being attached to the valve stem (3) and being movable in the direction of the longitudinal axis of the valve stem (3) together with the gas exchange valve (1). The arrangement comprises means (7, 14) for introducing pressurized charge from an air intake duct (10) of the engine air into the chamber (5) between the thrust means (6, 19) and the inner end of the chamber (5) for assisting in keeping the valve (1) closed. The invention also concerns a cylinder head (9).