Sealed Proportional Fuel Valve Venting for Faster Response
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Solution Overview
Problem
Proportional control valves in gasoline fuel injection systems face issues with slowed response times and loss of functional stroke length due to fuel entrapment in the fluid chamber, leading to increased costs and performance degradation.
Innovation Solution
A proportional control valve design featuring a metering assembly with an armature biasing spring, a vent valve, and a metering piston assembly that includes a seal and vent valve seat, allowing trapped pressure to be relieved through a small flow passage between the inert internal volume and the plenum, reducing the risk of valve failure and enabling a weaker actuator mechanism.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a proportional control valve is used to regulate fuel volume, then fuel delivery control is improved, but response time deteriorates due to fuel entrapment in the fluid chamber
Solution Approach 1:
The vent valve opens before the metering piston reaches its full travel position, proactively relieving trapped pressure in the fluid chamber. This preliminary action prevents pressure buildup that would otherwise retard piston motion and slow response time, allowing the piston to complete its stroke without resistance from trapped fuel pressure.
2Productivity
If a proportional control valve is used to regulate fuel volume, then fuel delivery control is improved, but functional stroke length deteriorates due to fuel entrapment
Solution Approach 1:
The vent valve opens before the metering piston reaches its full travel position, proactively relieving trapped pressure in the fluid chamber. This preliminary action prevents pressure buildup that would otherwise retard piston motion and slow response time, allowing the piston to complete its stroke without resistance from trapped fuel pressure.
3Manufacturing precision
If fuel leakage paths are restricted to control fuel flow, then fuel delivery precision is improved, but pressure relief capability deteriorates causing valve failure risk
Solution Approach 1:
The fluid chamber is segmented into two regions: a restricted leakage path region for precision fuel metering, and a vented region connected to the vent valve for pressure relief. This segmentation allows the system to maintain both precise fuel delivery control through restricted paths and reliability through active pressure management via the vent valve.
Solution Approach 2:
The vent valve acts as an intermediary mechanism between the trapped pressure in the fluid chamber and the external environment. It provides a controlled release path for excess pressure without interfering with the precision fuel metering function, thereby preventing valve failure while maintaining delivery accuracy.
4Reliability
If a stronger actuator mechanism is used to overcome trapped pressure, then valve performance is improved, but system cost increases
Solution Approach 1:
The vent valve acts as an intermediary mechanism between the trapped pressure in the fluid chamber and the external environment. It provides a controlled release path for excess pressure without interfering with the precision fuel metering function, thereby preventing valve failure while maintaining delivery accuracy.
Solution Approach 2:
The harmful trapped pressure is extracted from the fluid chamber through the vent valve, removing the obstacle that would require a stronger actuator. This extraction allows a weaker, more cost-effective actuator to suffice while maintaining reliable valve 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 improves response time and reduces the risk of valve failure, allowing for the use of a weaker actuator mechanism while maintaining efficient fuel delivery, thus enhancing the overall performance and reliability of the fuel injection system.
Implementation Method 1
As a command to deliver fuel is received the solenoid enters an energized state which will begin to lift the armature assembly, overcoming the armature biasing spring
Implementation Method 2
The vent valve, such as a ball, is affixed to the armature and the metering piston assembly is configured around the vent valve in a manner that couples the metering piston to the armature
Implementation Method 3
The armature biasing spring will push the metering assembly to the home position and fully close the variable orifice
Data Source
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AI summary
The proportional control valve for a fuel pump has a metering assembly within a tightly fit bore and a vent valve. The metering assembly includes a metering piston assembly, a piston biasing spring, an armature and a vent valve. The vent valve, such as a ball, is affixed to the armature and the metering piston assembly is configured around the vent valve in a manner that couples the metering piston to the armature. The metering piston assembly comprises a metering piston and a vent valve seat, permanently joined together, which contain a seal and a seat surface respectively between which the vent valve is permitted to move during the operation of the proportional control valve.