Inlet Valve Assembly Damping for Fuel Pump Impact Control
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Solution Overview
Problem
The high velocity movement of components in existing metering valves in fuel pumps for internal combustion engines leads to impact damage, cavitation, disassembly of press-fit components, noise, vibration, and harshness, as well as unwanted fuel delivery due to clashes between components.
Innovation Solution
An inlet valve assembly with a first biasing means to move towards an open position and a second biasing means to control the speed of the valve member, reducing the impact of component clashes by using a damping spring to limit movement and provide a controlled stop during transition.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the inlet valve member is allowed to move at high velocity between open and closed positions, then the response time and fuel metering accuracy are improved, but impact damage to components, cavitation, and system failures occur
Solution Approach 1:
A second spring (damping spring) is introduced that acts as a cushioning element during valve opening. This spring is pre-configured to engage and provide damping force before the valve member reaches full open position, reducing impact velocity and preventing damage to the armature, mechanical stop, and other components while maintaining fast response capability.
Solution Approach 2:
The system transitions from a single-spring system to a dual-spring system with different characteristics. The first spring provides strong biasing for fast closing response, while the second spring provides progressive damping during opening. This parameter change in the biasing mechanism allows simultaneous achievement of fast response and impact reduction.
2Productivity
If the inlet valve member moves quickly to respond to fuel delivery requirements, then the productivity and response time are improved, but noise, vibration and harshness (NVH) increase
Solution Approach 1:
The second damping spring is positioned to engage before the valve member reaches extreme positions, providing progressive cushioning that reduces velocity and minimizes impact-induced noise and vibration while preserving the ability to open and close quickly for fuel delivery response.
Solution Approach 2:
The second spring acts as an intermediary element between the valve member and the mechanical stop, absorbing and dissipating energy that would otherwise be transmitted as noise and vibration to the pump structure, thereby reducing NVH while maintaining productivity.
3Device complexity
If a mechanical stop is used to limit valve member travel, then the device complexity is reduced, but impact damage to the armature and stop occurs
Solution Approach 1:
The second damping spring is configured to engage and provide cushioning force before the valve member contacts the mechanical stop during opening. This beforehand cushioning reduces the impact velocity and force, preventing damage to both the armature and mechanical stop while maintaining the simplicity of the mechanical stop structure.
Solution Approach 2:
The damping spring applies a preliminary opposing force to the valve member's motion before impact occurs, counteracting the harmful impact effects in advance. This preliminary anti-action reduces the severity of the clash between the armature and mechanical stop, extending component life while keeping the structure simple.
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
Reduces the likelihood of damage to components and improves performance by minimizing component clashes, reducing noise and vibration, and ensuring controlled fuel delivery.
Implementation Method 1
a first biasing means configured to bias the inlet valve member in a first direction, d1, towards the open position
Implementation Method 2
a second biasing means configured to reduce the speed of the inlet valve member when the inlet valve member is moving in the first direction, d1, towards the open position
Data Source
AI summary
An inlet valve assembly of a fluid pump comprises an inlet valve member movable between a closed position and an open position. In the closed position the inlet valve member is arranged to block a pump chamber inlet to prevent fluid from entering or exiting a pump chamber of the fluid pump through the pump chamber inlet. In the open position the inlet valve member is arranged to allow fluid to enter or exit the pump chamber through the pump chamber inlet. The inlet valve assembly further comprises a first biasing means configured to bias the inlet valve member in a first direction, d1, towards the open position, when the inlet valve member is in the closed position; and a second biasing means configured to reduce the speed of the inlet valve member when the inlet valve member is moving in the first direction, d1, towards the open position.