Common Rail Fuel Injector Damping Structure for Stable Multi-Injection
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Solution Overview
Problem
The high-pressure common rail fuel injector in diesel engines experiences poor combustion performance due to significant fuel injection accuracy reduction caused by pressure fluctuations between multiple injections, leading to unstable fuel injection characteristics.
Innovation Solution
A high-pressure common rail fuel injector design incorporating a throttling damping-accommodating effect, featuring a pressure fluctuation absorption assembly with a multi-stage damping structure, including a damping-accommodating type piston sleeve and throttle orifices, to absorb pressure fluctuations and stabilize fuel injection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a conventional fuel injector is used in the HPCR system, then the fuel injection system can operate, but the fuel injection accuracy deteriorates significantly due to pressure fluctuations between multiple injections
Solution Approach 1:
The patent introduces a damping-accommodating type piston sleeve with throttle orifices that acts as a buffer between the fuel inlet and the control valve. This damping assembly absorbs pressure fluctuations before they reach the control valve and nozzle, cushioning the system against pressure variations that would otherwise degrade injection accuracy. The throttle orifices create flow resistance that dampens pressure waves, while the piston sleeve accommodates volume changes during pressure transitions.
Solution Approach 2:
The damping-accommodating type piston sleeve serves as an intermediary component between the fuel supply system and the injection control system. It mediates the transmission of pressure fluctuations by introducing a damping element that filters out harmful pressure variations while allowing steady fuel flow to pass through. This intermediary structure protects the precision control valve and nozzle from direct exposure to unstable fuel pressure.
2Productivity
If the interval between two adjacent injections is shortened to meet engine operating requirements, then the engine can operate normally, but the fuel injection accuracy deteriorates due to pressure fluctuation influence
Solution Approach 1:
The damping assembly is positioned upstream of the control valve to cushion pressure fluctuations before they can affect subsequent injections. This allows the system to maintain high injection frequencies while protecting the injection precision through pre-damping of pressure variations in the fuel line.
Solution Approach 2:
The damping-accommodating type piston sleeve maintains continuous fuel flow while filtering out pressure fluctuations. It ensures that the fuel supply remains continuous and stable throughout multiple rapid injections, allowing the system to operate at high injection frequencies without sacrificing accuracy between adjacent injections.
3Measurement precision
If a pressure fluctuation absorption assembly is added to stabilize fuel injection, then the injection accuracy improves, but the device complexity increases
Solution Approach 1:
The damping-accommodating type piston sleeve is designed to perform multiple functions within a single component: it acts as a damping element to absorb pressure fluctuations, serves as an accumulator to accommodate volume changes, and functions as a flow guide for fuel passage. This multi-functionality reduces the need for separate components, thereby limiting the increase in device complexity while achieving pressure stabilization.
Solution Approach 2:
The throttle orifices are integrated into the wall structure of the piston sleeve, and the piston sleeve itself is nested within the fuel inlet passage of the control valve assembly. This nested integration allows the damping function to be incorporated within existing structural spaces, minimizing the overall increase in device complexity while adding the pressure fluctuation absorption capability.
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 effectively absorbs pressure fluctuations through a multi-stage damping action, ensuring stable fuel injection performance by utilizing the inherent mass and throttling damping of the throttle orifices, thereby improving the accuracy and consistency of fuel injection.
Implementation Method 1
utilizing the inherent mass and throttling damping of the throttle orifices
Implementation Method 2
utilizing the inherent mass and throttling damping of the throttle orifices
Data Source
AI summary
The present disclosure provides a high-pressure common rail fuel injector capable of achieving highly stable injection based on the throttling damping-accommodating effect in the present disclosure, comprising a fuel injector housing, a fuel pipe connector, an accumulator chamber, a fuel chamber control valve, a pressure fluctuation absorption assembly, a control valve assembly and a nozzle assembly; the accumulator chamber is installed in the fuel injector housing, and the fuel pipe connector is installed above the accumulator chamber; the fuel chamber control valve, the pressure fluctuation absorption assembly and the control valve assembly are installed in the fuel injector housing, and the nozzle assembly is arranged below the control valve assembly; and the accumulator chamber is separated into a main accumulator chamber, an auxiliary accumulator chamber and a fuel-return accumulator chamber.