Throttle-Body Charge Forming With Upstream Fuel-Air Mixing
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Solution Overview
Problem
Existing fuel injection systems struggle with inefficient mixing of fuel and air at lower pressures, leading to suboptimal combustion in internal combustion engines.
Innovation Solution
A charge forming device with a throttle body, throttle valve, fuel metering valve, and nozzle body that enhances fuel and air mixing by incorporating a fuel passage and air passage, where air is mixed with fuel upstream of the fuel chamber, and a nozzle body outlet with controlled flow areas to optimize the mixture before discharge into the throttle bore.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If fuel is injected at high pressure (6-80 psi above atmospheric), then fuel mixing and dispersion is improved, but fuel flow velocity decreases at lower pressures leading to poor mixing
Solution Approach 1:
The fuel injection system is segmented into multiple injection points or stages, allowing fuel to be injected at different pressures or locations within the combustion chamber. This segmentation enables effective mixing even at lower overall pressures by creating multiple dispersed fuel streams that collectively achieve good distribution.
Solution Approach 2:
The invention introduces a spatial dimension to the mixing process by injecting fuel in a pattern that creates three-dimensional dispersion within the combustion chamber. Rather than relying solely on pressure-driven linear flow, the fuel is distributed across multiple spatial zones, enhancing mixing efficiency at lower pressures through geometric arrangement.
2Quantity of substance
If fuel is injected at high velocity, then fuel mixing with air is improved, but device complexity increases to maintain high pressure
Solution Approach 1:
The system utilizes the engine's own operating conditions (intake manifold pressure, piston motion, ambient air flow) to facilitate fuel mixing. Rather than requiring complex external pressure regulation systems, the injection mechanism leverages the natural pressure differentials and air flow patterns already present in the engine, achieving effective mixing through self-service principles.
Solution Approach 2:
The invention changes the operational parameters of fuel injection by adjusting injection timing, duration, and pattern rather than relying on maintaining constantly high pressure. By varying these parameters dynamically based on engine conditions, the system achieves adaptability and effective mixing without complex pressure regulation hardware.
3Use of energy by moving object
If fuel pressure is reduced to lower than high pressure range, then energy consumption decreases, but fuel flow becomes slower and mixing is insufficient
Solution Approach 1:
The system performs preliminary fuel preparation actions such as pre-vaporization or pre-mixing in dedicated chambers or passages before the fuel enters the main combustion chamber. This preliminary action ensures that fuel is already partially mixed or vaporized, reducing the energy required during actual injection while maintaining effective mixing in the combustion chamber.
Solution Approach 2:
An intermediary medium or structure is introduced to facilitate fuel-air mixing at lower pressures. This could be a pre-chamber, vaporization zone, or specially designed mixing passage that acts as an intermediary between fuel injection and main combustion, enabling effective mixing without requiring high injection pressures.
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
Improves fuel and air mixing efficiency, resulting in a more consistent fuel mixture delivery to the engine, enhancing combustion performance across various engine operating conditions.
Implementation Method 1
Air in the feed passage is mixed with fuel in the fuel passage upstream of the fuel chamber
Implementation Method 2
a nozzle body outlet through which a mixture of fuel and air flows into the fuel chamber, and wherein a flow area of the nozzle body outlet is between 15% and 45% of the volume of the fuel chamber
Data Source
AI summary
A charge forming device for a combustion engine includes a throttle body having a throttle bore, an air passage having at least a portion in which air flows separate from the throttle bore and a throttle valve with a valve head movable relative to the throttle body. A nozzle body has a fuel passage and a feed passage, the fuel passage is arranged to receive fuel that exits a fuel outlet of a fuel metering valve, and the fuel passage is communicated with a fuel chamber through which fluid flows into the throttle bore, and the feed passage is communicated with the air passage to receive air from the air passage and the feed passage is communicated with the fuel passage upstream of the fuel chamber, wherein air in the feed passage is mixed with fuel in the fuel passage upstream of the fuel chamber.