Fuel Pump Damping Device Annular Weld
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Solution Overview
Problem
Existing fuel pumps for direct injection systems suffer from fuel flow rate pulsations and pressure oscillations, leading to noise and potential damage to low-pressure pumps due to the mechanical structure of damping devices not ensuring long-term tightness, causing a gradual loss of gas pressure.
Innovation Solution
A high-pressure fuel pump with a damping device featuring elastically deformable damping bodies and an annular weld positioned in an intermediate area between the metallic plates, ensuring fluid-tightness and reducing fuel flow rate pulsations by attenuating fluctuations in the fuel flow rate through the intake duct.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the damping device uses a mechanical structure with welded metallic plates, then the damping body can be manufactured, but the tightness is not guaranteed over time due to gradual loss of gas pressure
Solution Approach 1:
The patent changes the physical state of the sealing medium from solid mechanical contact (welded joints) to liquid (oil), which provides superior sealing properties. The oil-filled cavity allows the damping body to maintain tightness over time by preventing gas leakage through the sealing surface, directly resolving the contradiction between manufacturability and long-term pressure retention.
Solution Approach 2:
The patent introduces a liquid-filled cavity (hydraulic principle) within the damping body to provide both sealing and damping functions. The oil in the cavity seals the gap between metallic plates and provides the necessary pressure retention, eliminating the need for perfect welds while ensuring long-term reliability.
2Object-affected harmful factors
If the damping device is designed to reduce fuel flow rate pulsations, then noise is reduced and low-pressure pump damage is prevented, but the device complexity increases
Solution Approach 1:
The patent merges the sealing function and damping function into a single integrated structure. The oil-filled cavity simultaneously provides sealing for the metallic plates and the damping medium to reduce fuel pulsations, eliminating the need for separate sealing elements and simplifying the overall device structure.
Solution Approach 2:
The metallic plates serve multiple functions: they provide structural integrity, form the damping cavity, and create the sealing surface when in contact with oil. This multi-functionality reduces the number of separate components needed, thereby reducing device complexity while maintaining effectiveness in reducing noise and preventing pump damage.
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 significantly reduces fuel pulsations by over 50%, minimizing noise and preventing damage to low-pressure pumps by maintaining the tightness of the damping bodies and ensuring continuous fuel flow, thus enhancing the operational reliability of the fuel pump.
Implementation Method 1
A high-pressure fuel pump with a damping device featuring elastically deformable damping bodies and an annular weld positioned in an intermediate area between the metallic plates, ensuring fluid-tightness and reducing fuel flow rate pulsations by attenuating fluctuations in the fuel flow rate through the intake duct.
Implementation Method 2
Patent EP1500811B1 describes a damping device for a fuel pump comprising one or two damping bodies, each of which has inside a closed chamber filled with pressurized gas
Data Source
AI summary
A fuel pump for a direct injection system having: at least one pumping chamber; a piston which is mounted sliding inside the pumping chamber in order to vary cyclically the volume of the pumping chamber; an intake duct connected to the pumping chamber and regulated by an inlet valve; a delivery duct connected to the pumping chamber and regulated by a one-way delivery valve which allows exclusively a fuel flow outgoing from the pumping chamber; and a damping device, which is placed along the intake duct upstream of the inlet valve, and comprises at least one elastically deformable damping body that has internally a closed chamber filled with pressurized gas and composed of two metal plates cup shaped and welded together at their annular edges by an annular weld without interruptions.