Gas Injector With 3/2-Way Pilot Valve for Rapid Needle Control
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Solution Overview
Problem
Existing fuel injectors face challenges in achieving reliable and rapid stroke control of fuel gas nozzle needles, particularly at low pressures, which can hinder their use in high-speed engines and small engine installations.
Innovation Solution
A fuel injector design with multiple fuel gas nozzle valve members, each hydraulically controlled by a piston control arrangement with separate opening and closing pressure control chambers, utilizing a 3/2-way valve for simultaneous stroke control, independent of fuel gas pressure, allowing rapid and uniform injection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If fuel gas nozzle needle is controlled only by fuel gas pressure, then the control system is simple, but the needle opens too slowly at low pressures
Solution Approach 1:
The control system is segmented into two independent pressure control chambers: a first control chamber that receives control fluid to generate opening force, and a second control chamber that receives fuel gas pressure to generate closing force. This segmentation allows each chamber to be optimized for its specific function, enabling rapid needle opening while maintaining system simplicity.
Solution Approach 2:
A pilot valve is introduced as an intermediary component to control the flow of control fluid to the first control chamber. This pilot valve enables precise timing of the opening force application, allowing the needle to open rapidly when needed while keeping the overall control system relatively simple through centralized pilot control.
2Area of stationary object
If a 4/2-way valve is used for joint stroke control, then stroke control is achieved, but the injector cannot be integrated into smaller engines
Solution Approach 1:
Instead of using a complex 4/2-way valve to control both opening and closing, the invention inverts the approach by using a simple 3/2-way pilot valve to control only the opening side (first control chamber), while the closing side (second control chamber) is naturally controlled by fuel gas pressure. This inversion dramatically reduces the injector size while maintaining full stroke control capability.
Solution Approach 2:
The second control chamber is designed to be self-regulating, where fuel gas pressure automatically provides the closing force on the needle. This self-service approach eliminates the need for additional active control components for the closing action, reducing overall injector size and complexity while preserving stroke control functionality.
3Adaptability or versatility
If fuel gas pressure is used to control needle opening, then the system is simple, but control is not independent of fuel medium pressure
Solution Approach 1:
A pilot valve serves as an intermediary that decouples the control fluid system from the fuel gas pressure system. The pilot valve uses a small amount of control fluid to regulate the opening force independently of fuel gas pressure variations, enabling the needle opening control to be independent of the fuel medium while keeping the control system relatively simple through the use of this single intermediary component.
4Reliability
If multiple fuel gas nozzle valves are controlled individually, then each valve can be optimized, but the control system becomes complex
Solution Approach 1:
The pilot valve is designed with multi-functionality to control multiple fuel gas nozzle needle valves simultaneously through a single device. By using a common control fluid supply and a single pilot valve mechanism, the system achieves reliable synchronized control of multiple needles without requiring individual control systems for each valve, thus maintaining reliability while minimizing complexity.
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
Enables rapid and uniform fuel gas discharge into the combustion chamber, suitable for small engines, with flexible operation independent of fuel medium pressure levels, ensuring robust and efficient fuel injection.
Implementation Method 1
a hydraulic pressure in the closing pressure control chamber being controllable via the 3/2-way valve
Implementation Method 2
with a uniformly set, uniformly effective opening force against the fuel gas nozzle valve member acting under hydraulic load
Data Source
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AI summary
The invention relates to a fuel injector (1) for operating with combustible gas. The fuel injector has a plurality of combustible-gas nozzle valve elements (9), and the stroke of each of the combustible-gas nozzle valve elements can be controlled by means of a paired hydraulic piston control assembly (55) of the fuel injector (1), wherein each piston control assembly is formed by two control chambers (59, 61) and a piston section (63) on the combustible-gas nozzle valve element paired with the piston control assembly, said piston section separating the control chambers in such a way that their volumes can be varied, and the fuel injector is designed to control the stroke of the combustible-gas nozzle valve elements in tandem using a 3/2-way valve (67), by means of which the hydraulic pressure in one of the two control chambers of the piston control assemblies is controlled.