Fuel Injector Coupler Valve for Stable Refilling
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Solution Overview
Problem
Current fuel injectors with hydraulic couplers face issues with leakage and pressure drop due to the coupler gap space being emptied during frequent injections, leading to reduced injection quantity and potential absence of injections, especially when injection intervals are short.
Innovation Solution
A non-deformable valve, designed as a sleeve or disk, is placed between the filling channel and the coupler gap space to create a higher pressure and improve refilling, ensuring rapid and constant refilling between injections without compromising the coupler's rigidity or increasing voltage requirements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the coupler gap space is filled with hydraulic fluid to compensate for leaks, then the coupler function is maintained, but the filling channel must remain open which causes pressure loss and reduces injection quantity
Solution Approach 1:
The filling channel is designed to dynamically open and close based on pressure differential. During injection, the channel closes to maintain pressure and prevent leakage. During injection pauses, the channel opens to allow refilling. This dynamic behavior resolves the contradiction by maintaining coupler function stability without continuous pressure loss.
Solution Approach 2:
The system utilizes changes in pressure parameters to control the filling channel state. When pressure in the coupler gap space exceeds pressure in the low-pressure space, the channel closes. When pressure equalizes or reverses during injection pauses, the channel opens. This parameter-based control maintains injection quantity while ensuring reliable coupler refilling.
2Productivity
If frequent injections are made with short intervals, then productivity is improved, but the coupler gap space is emptied faster than it can be refilled, leading to complete absence of injections
Solution Approach 1:
The filling channel opens during injection pauses to perform preliminary refilling of the coupler gap space before the next injection cycle begins. This preliminary action ensures that the coupler is fully refilled even when injection intervals are short, preventing complete absence of injections and maintaining injection continuity.
Solution Approach 2:
The system maintains continuous operational capability by ensuring the coupler gap space is continuously refilled during injection pauses. The filling channel's automatic opening during pauses ensures uninterrupted preparation for the next injection, maintaining both high productivity and injection reliability even under frequent injection conditions.
3Speed
If a valve is added to control the filling channel, then refilling speed is improved, but device complexity increases
Solution Approach 1:
The filling channel is designed to automatically open and close based on pressure differential without requiring external control mechanisms. The pressure-driven operation eliminates the need for complex valves or control systems, achieving fast refilling during injection pauses while maintaining simple device architecture.
Solution Approach 2:
The system uses hydraulic pressure differentials to control the filling channel state. The pressure in the coupler gap space automatically drives the channel closure during injection, and pressure equalization during injection pauses drives the channel opening. This hydraulic control achieves rapid refilling without mechanical valves, minimizing device 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
The solution enhances the speed stability of the fuel injector by maintaining higher pressure in the hydraulic fluid space during injection pauses, allowing for quasi-constant coupler function and preventing the absence of injections, even with high-frequency injection cycles.
Implementation Method 1
the sleeve is pushed away from the inner wall of the coupler body by the pressure in the filling channel
Implementation Method 2
the sleeve... seals when closed thus the filling channel reliably
Implementation Method 3
a hydraulic coupler, which has a coupler piston that can move in a coupler body and a working piston that is coupled to it via a coupler gap space
Implementation Method 4
a spring that pushes the coupler piston and the working piston apart
Data Source
Figure 1
Figure 2~3
Figure 4~5
AI summary
The invention relates to a fuel injector 1 of a fuel injection system of an internal combustion engine, wherein the fuel injector 1 has a hydraulic coupler 25 comprising a coupler piston 27 movable in a coupler body 33 and a working piston 28, also movable in the coupler body 33 and coupled thereto via a coupler gap chamber 29, and wherein the coupler gap chamber 29 is connected via at least one filling channel 41 to a low-pressure chamber 22 arranged outside the coupler body 33. According to the invention, a fuel injector 1 with a coupler 25 is provided in which the filling of a coupler gap chamber 29 with high-pressure fluid is improved. This is achieved by arranging a one-piece, non-deformable valve, which switches upon a change in position, in the region of a connection between the filling channel 41 and the coupler gap chamber 29. This valve is designed as a sleeve 42, 42a or disc 44, 44a.