Gas Direct Injector with Remote Elastomer Seal
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Solution Overview
Problem
Conventional direct gas injectors experience high tip leakage due to the high temperature, which elastomeric seals cannot effectively manage, as metal-to-metal sealing solenoids fail to meet leakage requirements.
Innovation Solution
A gas direct injector design featuring an armature tube with a movable magnetic armature, an electromagnetic coil, and elastomer sealing at a remote location from the injector tip, utilizing springs to bias valves for sealing and fuel passage control, ensuring low leakage by engaging and disengaging seats to regulate fuel flow.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If metal-to-metal sealing solenoid valve is used at the injector tip, then the sealing structure can withstand high temperature, but the leakage performance deteriorates and cannot meet leakage requirements
Solution Approach 1:
The patent introduces an intermediary elastomeric seal component positioned between the high-temperature injector tip and the metal valve mechanism. This elastomeric seal acts as a mediator that isolates the metal-to-metal sealing surfaces from direct exposure to high temperatures, allowing the metal sealing surfaces to maintain their structural integrity and sealing effectiveness without deforming due to thermal exposure.
Solution Approach 2:
The sealing system is segmented into distinct functional zones: an elastomeric seal section that handles thermal isolation and a metal-to-metal sealing section that handles the actual sealing function. This segmentation allows each component to operate within its optimal temperature range, with the elastomeric seal protecting the metal sealing surfaces from thermal degradation.
2Reliability
If elastomeric seal is placed at the injector tip, then leakage performance improves, but the seal deteriorates due to high temperature exposure
Solution Approach 1:
The elastomeric seal serves as an intermediary protective layer between the high-temperature combustion environment and the sealing mechanism. By positioning the elastomeric seal at the tip, it directly faces the high temperature exposure while protecting the metal valve components from thermal damage, thus extending the life of the sealing system.
Solution Approach 2:
The patent changes the material parameter of the seal from metal-to-metal contact to elastomeric material, which has different thermal and sealing properties. The elastomeric material provides both sealing functionality and thermal isolation, changing the physical parameters of the sealing interface to accommodate high-temperature operation.
3Reliability
If additional elastomer sealing valve is added remote from the injector tip, then leakage requirements are met, but the device complexity increases
Solution Approach 1:
The patent merges the elastomeric sealing function with the existing metal valve structure by integrating the elastomeric seal into the valve body assembly. This combination allows the system to achieve the required leakage performance while minimizing the increase in overall complexity, as the elastomeric seal works in conjunction with rather than entirely separate from the metal valve components.
Solution Approach 2:
The elastomeric seal component performs multiple functions simultaneously: it provides sealing, isolates thermal energy, and protects the metal valve surfaces. This multi-functionality reduces the need for additional separate components, thereby limiting the increase in device complexity while achieving the required leakage performance.
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 effectively limits leakage to less than 0.2 cc/mm at 1500 kPa and allows for up to 12 g/s fuel flow rate at 20 Bar, maintaining efficient fuel injection while avoiding high-temperature exposure of the elastomer seal.
Implementation Method 1
An electromagnetic coil is associated with the stator and the armature. A movable, magnetic armature is coupled to the armature tube to define a first valve.
Implementation Method 2
A first spring is constructed and arranged, when the coil is not activated, to bias the armature tube so that the distal end engages in a sealing manner with the first seat close the passage structured and limit leakage of the gaseous fuel from the outlet.
Implementation Method 3
A second spring is constructed and arranged, when the coil is not activated, to bias the second valve so that a seating surface thereof engages the second seat to close the outlet.
Implementation Method 4
pressure of the gaseous fuel causes the second valve to move against the bias of the second spring so that the seating surface disengages from the second seat to cause the gaseous fuel to exit the outlet.
Data Source
AI summary
An injector has an inlet and an outlet and an armature tube having passage structure and having a distal end spaced from the outlet. The passage structure communicates with the inlet. A movable, magnetic armature is coupled to the armature tube. An electromagnetic coil is associated with a stator and with the armature. A first spring is constructed and arranged, when the coil is not activated, to bias the armature tube so that the distal end engages in a sealing manner with a first seat to limit leakage of the gaseous fuel from the outlet. A second valve is movable in a valve body. A second spring is constructed and arranged, when the coil is not activated, to bias the second valve so that a seating surface thereof engages a second seat to close the outlet.