High-Pressure Pump Valve Piston Cavitation Volume Design
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Solution Overview
Problem
High-pressure pumps in fuel injection systems suffer from cavitation erosion at the pressure valve seat, leading to a loss of sealing function and premature failure due to rapid pressure changes causing vapor bubble collapse and local pressure waves.
Innovation Solution
A cavitation volume is formed upstream of the valve seat on the high-pressure valve piston, redirecting vapor formation away from the valve seat, using a combination of a blind hole volume and connecting channels to create a closed end for vapor formation, thus preventing erosion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional pressure valve design is used, then the pump structure is simple, but cavitation erosion occurs at the valve seat leading to loss of sealing function
Solution Approach 1:
The valve piston is segmented into functional zones: a cavitation volume (annular groove) upstream of the valve seat, and the valve seat area itself. This segmentation isolates the cavitation phenomenon to a specific region, protecting the valve seat from erosion while maintaining the simple valve structure.
Solution Approach 2:
The cavitation volume acts as an intermediary chamber between the compression space and the valve seat. It serves as a buffer zone where vapor bubbles can form and collapse without directly impacting the valve seat, thereby mediating the cavitation effect and protecting the sealing surface.
2Quantity of substance
If the cavitation volume is positioned too close to the valve seat, then the flow volume increases, but the valve seat becomes susceptible to cavitation erosion
Solution Approach 1:
Different regions of the valve piston are assigned different functional qualities: the cavitation volume region accommodates vapor formation with larger flow volume, while the valve seat region maintains precise sealing geometry. This local differentiation allows the system to benefit from increased flow volume without compromising the valve seat against cavitation erosion.
Solution Approach 2:
The cavitation volume is positioned in the axial dimension upstream of the valve seat, creating a spatial separation between the vapor formation zone and the sealing zone. This dimensional arrangement allows the cavitation volume to be sufficiently large for flow requirements while maintaining adequate distance from the valve seat to prevent erosion.
3Object-affected harmful factors
If the cavitation volume is positioned too far from the valve seat, then cavitation erosion is prevented, but the flow volume upstream of the valve seat decreases
Solution Approach 1:
The cavitation volume is designed with dimensions that provide sufficient distance from the valve seat to prevent erosion, while still maintaining adequate flow volume through the annular groove configuration. The groove's cross-sectional area and length are optimized to deliver partial excess flow capacity without requiring the cavitation volume to be immediately adjacent to the valve seat.
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 design effectively reduces cavitation erosion on the valve seat, ensuring the sealing function is maintained over the service life of the high-pressure pump by shifting vapor formation away from the valve seat area, thereby extending the pump's operational lifespan.
Implementation Method 1
When operating the high-pressure pump, cavitation erosion can occur under certain operating conditions, i.e. material removal from the pressure valve in the valve seat area, which can lead to the loss of the sealing function of the pressure valve after a short period of time
Implementation Method 2
The cavitation volume represents a closed end for the flow when the hydraulic connection is closed. This leads to the formation of vapor in the cavitation volume
Implementation Method 3
The valve face cooperates with the valve seat, thereby opening and closing hydraulic communication from the compression space to a high-pressure bore
Implementation Method 4
The high-pressure pump compresses a fluid, in particular fuel
Data Source
Figure 1
Figure 2~3
AI summary
The invention relates to a high pressure pump (100) for conveying fluid which is under high pressure, wherein the high pressure pump (100) comprises a variable-volume compression chamber (6) and a pressure valve (101). The pressure valve (101) has a valve surface (51) formed on a high pressure valve piston (40) and has a valve seat (15) formed on a valve carrier (10). The valve surface (51) interacts with the valve seat (15) and thereby opens and closes a hydraulic connection from the compression chamber (6) to a high pressure borehole (9). Upstream of the valve seat (15), a cavitation volume (50) is formed in the high pressure valve piston (40).