High-Pressure Fuel Pump Valve Mechanism Cavitation Prevention
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Solution Overview
Problem
The existing high-pressure fuel pump discharge valve mechanism suffers from limited fuel passage, leading to backward fuel flow and cavitation, which damages the valve seat surface, compromising its functionality.
Innovation Solution
A valve mechanism with a seat member, a valve body, and a housing member, featuring a first and second fluid flow-path configuration that increases the cross-sectional area of the second flow-path to 0.18 mm square or above, allowing fuel to flow backward through both paths, reducing the flow rate and preventing cavitation damage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If the fuel passage is limited in the discharge valve mechanism, then the valve structure is compact and simple, but the fuel flow rate increases during backward flow causing cavitation and seat surface damage
Solution Approach 1:
The fuel passage is segmented into two separate paths: a first fuel passage for forward flow and a second fuel passage for backward flow. This segmentation allows the backward flow to be directed through a dedicated path with sufficient cross-sectional area (0.18 mm² or more), preventing cavitation while maintaining overall structural compactness.
Solution Approach 2:
The housing member acts as an intermediary component that houses both the first and second fuel passages. It provides the structural framework that enables the dual-passge configuration, mediating between the compact design requirement and the cavitation prevention requirement by integrating both flow paths within a single component.
2Object-affected harmful factors
If the cross-sectional area of the fuel passage is increased, then cavitation is suppressed, but the device size increases
Solution Approach 1:
Instead of increasing the cross-sectional area of a single fuel passage, the invention segments the flow paths so that the second fuel passage (for backward flow) has a sufficient cross-sectional area of 0.18 mm² or more. This segmented approach allows cavitation suppression in the critical backward flow path without unnecessarily increasing the overall device size.
3Device complexity
If a single fuel passage is used, then the passage structure is simple, but the backward flow rate is high causing cavitation
Solution Approach 1:
The fuel passage is divided into two distinct paths with different functions: the first fuel passage for forward flow and the second fuel passage for backward flow. This segmentation enables independent optimization of each path's characteristics, allowing the second passage to have sufficient cross-sectional area for low-velocity backward flow while keeping the overall passage structure relatively 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
This configuration reduces the backward flow rate of fuel, suppressing cavitation and maintaining the valve's functionality by distributing the flow evenly, thus preventing damage to the seat surface.
Implementation Method 1
This easily induces cavitation and decay energy of the generated cavitation might damage the seat surface
Data Source
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AI summary
Provided is a solution to a problem on a discharge valve mechanism disposed at an exit of a pressurizing chamber of a high-pressure fuel supply pump, that is, an occurrence of a backward flow of the fuel concentrates on a limited fuel passage, leading to a higher fuel flow rate, and this easily induces the occurrence of cavitation, and collapse of the generated cavitation might damage a seat surface, making it difficult to maintain valve functions. The present invention provides a valve mechanism including a seat member having a seat section, a valve body configured to attach to or detached from the seat section, and a housing member arranged on an outer peripheral side of the seat member. A first fluid flow-path is formed to connect an inner peripheral side and an outer peripheral side of the seat section in a case where the valve is detached from the seat section. A second fluid flow-path is formed to be connected with the first fluid flow-path, between an outer peripheral surface of the seat member and an inner peripheral surface of the housing member, or between an outer peripheral surface of the valve body and the inner peripheral surface of the housing member. The cross-sectional area along the axial direction of the valve mechanism of the second fluid flow-path is 0.18 mm square or above.