Direct Needle Control Fuel Injector with Segmented Valve
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Solution Overview
Problem
Conventional diesel injector needle control valves, whether 2-way or 3-way, face challenges in achieving optimal flexibility and cost-effectiveness, with 2-way valves offering simplicity but suboptimal control and 3-way valves providing superior control at higher complexity and cost.
Innovation Solution
A diesel injector design featuring an electromagnetically actuated 3-way control valve with a check disk that allows independent control of needle opening and closing velocities, utilizing a combined spool/poppet valve for low leakage and a check disk with different flow areas for selective control, enabling slower opening and faster closing of the needle.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If 2-way valves are used for direct needle control, then device complexity and cost are reduced, but flexibility in controlling needle motion during opening and closing is compromised
Solution Approach 1:
The control system is segmented into two independent 2-way valves: one controlling needle opening and another controlling needle closing. This segmentation allows each valve to be optimized for its specific function while maintaining overall system simplicity. The opening control valve and closing control valve operate independently, providing flexible control over the entire needle motion cycle without requiring a complex 3-way valve structure.
Solution Approach 2:
Two standard 2-way valves are used to perform the functions traditionally requiring a specialized 3-way valve. By making the system multi-functional through the use of two simpler components, the invention achieves the versatility of a 3-way valve while maintaining the simplicity and cost-effectiveness of 2-way valve technology.
2Adaptability or versatility
If 3-way valves are used for needle control, then flexibility in controlling needle motion is improved, but device complexity and cost increase
Solution Approach 1:
The single 3-way valve is segmented into two separate 2-way valves. This segmentation simplifies the overall valve structure while maintaining the ability to independently control needle opening and closing motions. Each 2-way valve handles a specific phase of needle motion, eliminating the complexity of the 3-way valve's single body design with multiple ports.
Solution Approach 2:
The control system uses intermediate control volumes and pressure chambers to mediate between the two 2-way valves and the needle. These intermediary elements transmit and transform the control signals from each valve, enabling coordinated control of needle opening and closing without requiring a complex integrated 3-way valve structure.
3Ease of manufacture
If conventional 2-way direct needle control is used, then cost and simplicity are improved, but control precision over wide pressure range is reduced
Solution Approach 1:
The control system provides different local qualities for opening and closing control. Separate 2-way valves with independently adjustable parameters allow optimization of control characteristics for each phase of needle motion. This enables precise control of needle velocity during opening and closing independently, achieving high manufacturing precision while maintaining the simplicity of 2-way valve construction.
Solution Approach 2:
The control system is made dynamic through independently adjustable valve parameters and control pressures. Each 2-way valve can be adjusted to provide optimal control characteristics across the entire pressure range, allowing the system to adapt to varying operating conditions while maintaining manufacturing simplicity.
4Adaptability or versatility
If previous 3-way direct needle control injectors are used, then needle controlling flexibility is improved, but device complexity and cost increase, and orifice positioning is suboptimal
Solution Approach 1:
The complex 3-way valve structure is segmented into two simpler 2-way valves. This segmentation maintains needle control flexibility by providing independent control of opening and closing phases, while simultaneously reducing device complexity and cost. Each 2-way valve can be optimized for its specific function without the structural constraints of a single 3-way valve body.
Solution Approach 2:
Instead of using a single complex 3-way valve, the invention uses two copies of simpler 2-way valves to achieve the same functional outcome. This copying approach provides the benefits of a 3-way valve's independent control capability while avoiding its structural complexity and high cost.
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 achieves precise needle velocity control over a wide pressure range, enabling small injection quantities and reduced particulate emissions, while maintaining a simple and cost-effective structure.
Implementation Method 1
an electromagnetically actuated 3-way control valve with a spool poppet
Implementation Method 2
The check disk is able to move between its lower stop and upper stop according to the pressure differential between above and below the check disk
Implementation Method 3
In the supply position, the high pressure in the control volume 4 keeps the needle 8 on its seat 16, thereby preventing fuel from entering the engine cylinder
Data Source
AI summary
Direct needle control fuel injectors and methods disclosed. The preferred embodiment injectors have a needle within a needle chamber for movement between a closed position preventing injection of fuel and an open position allowing injection of fuel, a source of high pressure fuel coupled to the needle chamber to provide fuel for injection and to hydraulically urge the needle to the open position by pressurizing a first hydraulic area associated with the needle, a needle control hydraulic area having a second hydraulic area disposed to urge the needle to the closed position when the second hydraulic area is exposed to fuel under pressure, and valving coupled to the source of high pressure fuel and a vent to controllably couple the hydraulic area of the needle control member to the high pressure fuel or to the vent.