Fuel Injection Damper for Pulsation Pressure Reduction
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Solution Overview
Problem
The diesel fuel injection system faces challenges in reducing pulsation pressure due to high pressure peaks, which complicates the high pressure pump structure and reduces layout flexibility in the engine room, as existing dampers struggle to effectively mitigate the high pressure peaks in the low pressure circuit.
Innovation Solution
A damper is integrated into the fuel line connecting the low pressure pump and high pressure pump, featuring a pressure absorption body with a gas-filled chamber and metal diaphragm members that deform elastically to absorb pressure peaks, allowing for a compact design that reduces the impact of high pressure peaks on the low pressure circuit.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a damper is installed in the high pressure pump housing to reduce pulsation pressure, then the pulsation pressure in the high pressure pump housing is reduced, but the structure of the high pressure pump becomes complicated and its size increases
Solution Approach 1:
The damper is extracted from the high pressure pump housing and installed as a separate component in the low pressure circuit. This separates the pulsation damping function from the high pressure pump structure, avoiding structural complication while maintaining the pulsation reduction effect.
Solution Approach 2:
The damper acts as an intermediary component installed in the fuel line between the low pressure pump and high pressure pump. It mediates the pulsation pressure by absorbing pressure peaks before they reach the high pressure pump, protecting the pump from pulsation damage without requiring structural modification.
2Object-affected harmful factors
If a damper with large surface area and large capacity is installed to inhibit high pressure peak, then the pulsation pressure is effectively reduced, but the high pressure pump and internal combustion engine grow in size, reducing layout flexibility
Solution Approach 1:
The damper utilizes pneumatic principles with a gas-filled chamber that compresses and expands to absorb pressure peaks. This pneumatic mechanism provides effective pulsation damping in a compact volume, avoiding the need for large mechanical dampers that would consume excessive engine room space.
Solution Approach 2:
The damper employs flexible metal diaphragms that deform elastically under pressure to absorb pressure fluctuations. These thin flexible membranes provide effective pulsation absorption without requiring large structural volume, maintaining compact engine room layout flexibility.
3Stress or pressure
If the average pressure of the low pressure circuit is low at about 0.5 MPa but the pressure peak is very high at 1.5 MPa or higher, then the pulsation pressure is difficult to reduce only in the housing of the high pressure pump
Solution Approach 1:
The damper is installed in the low pressure circuit before the high pressure pump to preliminarily absorb pressure peaks generated by the low pressure pump. This preliminary damping action prevents high pressure peaks from propagating to the high pressure pump, making the damping system more effective despite the low average pressure environment.
Solution Approach 2:
The damper is designed with specific parameters optimized for low pressure circuit conditions, with a gas chamber pressure and diaphragm stiffness calibrated to effectively absorb pressure peaks occurring at 1.5 MPa or higher while operating in a circuit with 0.5 MPa average pressure.
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 effectively reduces pulsation pressure in the low pressure circuit, prevents the high pressure pump from growing in size, and enhances layout flexibility by minimizing the axial length of the fuel line and damper, ensuring efficient fuel injection while maintaining a compact engine design.
Implementation Method 1
a gas volume is defined by a membrane... pressure peaks... is reduced by deformation of metal diaphragms sealed up gas therebetween
Implementation Method 2
pressure peak... is reduced by deformation of metal diaphragms sealed up gas therebetween
Data Source
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AI summary
To provide a fuel injection system and a damper used in the fuel injection system, the fuel injection system being simply configured to eliminate an effect of a high pressure peak generated at a low pressure circuit at low pressure side and preventing a high pressure pump from being complicated and growing in size. A damper (10) is arranged in and fixed to a fuel line (24, 25), the damper (10) including a fuel line portion (6, 7, 8) which has both ends provided with a pair of fuel line connecting portions (6a, 6b, 7a, 7b, 8a, 8b) connected to the fuel line (24, 25) and which has an inner portion allowing passage of the fuel; a cover portion (1, 2) forming an enclosed room (C) arranged to extend from the fuel line portion (6, 7, 8); and a pressure absorption body (3) extending in a direction which intersects with a passing direction (9) of the fuel and arranged in the enclosed room (C).