Throttle Body Flow Directing Structure for Low-Speed Fuel-Air Mixing
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Solution Overview
Problem
Existing throttle body designs for internal combustion engines face challenges in efficiently mixing fuel and air, particularly at low speed and high load conditions, where current systems often result in engine lugging and require high fuel pressures, leading to inefficiencies and potential multiple fuel discharge events due to transient pressure waves.
Innovation Solution
The throttle body incorporates a main bore with a movable throttle valve head and a boost venturi, featuring non-planar portions and projections that direct air flow to enhance mixing and velocity, along with a flow directing feature that channels air towards the boost venturi, optimizing fuel and air mixture distribution and pressure management.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If high fuel pressure (6-80 psi) is used to facilitate fuel mixing and dispersion, then fuel and air mixing is improved, but fuel injection system complexity and potential multiple discharge events increase
Solution Approach 1:
The patent uses a venturi structure that leverages pneumatic principles to accelerate air flow and create a low-pressure zone that draws fuel into the air stream. The venturi effect converts air pressure energy into kinetic energy, creating a suction effect that atomizes fuel without requiring high fuel pressure from the injection system, thereby reducing system complexity while maintaining effective mixing.
Solution Approach 2:
The patent changes the pressure parameters of the air stream rather than the fuel stream. By creating a pressure differential through the venturi geometry, the system uses air pressure changes to control fuel atomization and distribution. This approach allows effective fuel-air mixing at lower fuel injection pressures, reducing the complexity of the fuel pressure regulation system.
2Power
If high fuel pressure is used to maintain mixture flow at low speed and high load, then engine power is maintained, but transient pressure waves cause multiple fuel discharge events
Solution Approach 1:
The venturi structure acts as an intermediary between the air stream and fuel injection. It mediates the interaction by using air flow dynamics to control fuel atomization, isolating the fuel injection system from direct exposure to transient pressure waves in the combustion chamber. This intermediary role stabilizes fuel discharge by allowing the venturi to smooth out pressure fluctuations before they reach the fuel injector.
3Quantity of substance
If conventional throttle valve design is used, then device simplicity is maintained, but fuel and air mixing efficiency is insufficient
Solution Approach 1:
The patent merges the throttle valve function with the venturi structure into a single integrated component. The throttle valve body incorporates the venturi geometry, combining flow control and fuel-air mixing functions in one structure. This integration improves mixing efficiency without proportionally increasing device complexity, as the additional mixing capability is achieved through geometric modification rather than adding separate components.
Solution Approach 2:
The venturi structure employs curved geometry to guide air flow smoothly and create the necessary pressure differential for fuel atomization. The curved walls of the venturi accelerate air flow and create a low-pressure zone that enhances fuel mixing. This use of curvature improves mixing efficiency while maintaining a relatively simple, manufacturable throttle body design.
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 improves fuel and air mixing, reduces engine lugging, and maintains efficient operation at low speed and high load conditions while using lower fuel pressures, minimizing transient reverse flow issues and enhancing airflow consistency to the engine.
Implementation Method 1
a boost venturi, featuring non-planar portions and projections that direct air flow to enhance mixing and velocity
Implementation Method 2
a flow directing feature that channels air towards the boost venturi, optimizing fuel and air mixture distribution and pressure management
Implementation Method 3
a throttle valve head movable between an idle and a wide open position to control at least some flow through the main bore to the engine
Data Source
AI summary
A throttle body may have a main bore for supplying a fuel and air mixture to an engine. A throttle valve head may be received in the main bore and movable between idle and wide open positions to control fluid flow through the main bore. A main fuel outlet and a boost venturi may open to the main bore and a flow directing feature may alter the velocity and/or direction of fluid flow in the main bore relative to the fuel outlet or boost venturi. The flow directing feature may be carried by the body, the throttle valve head, or the boost venturi.