Fuel Injection Valve Throttle Portion Dynamics
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Solution Overview
Problem
Fuel injection valves experience pressure pulsation issues during valve closing, which can lead to decreased fuel pressure and injection amount during opening, and are not effectively addressed by existing technologies.
Innovation Solution
A fuel injection valve design incorporating a throttle portion with a movable part and a throttle flow path that changes minimum flow path area based on needle position, allowing fuel to flow without throttling during opening and attenuating pressure pulsation during closing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a fixed orifice member is provided in the fuel flow path to reduce pressure pulsation, then pressure pulsation is reduced, but fuel pressure and injection amount decrease during valve opening
Solution Approach 1:
The throttle portion is designed with a movable part that can change the minimum flow path area dynamically based on needle position. During valve opening, the movable part positions to provide a larger flow area, maintaining fuel pressure and injection amount. During valve closing, it restricts flow area to attenuate pressure pulsation, thus resolving the contradiction between pressure pulsation reduction and fuel pressure maintenance
Solution Approach 2:
The system changes the flow path parameters (minimum flow path area) according to operational conditions. The movable part of the throttle portion adjusts the flow path geometry to provide different flow resistance levels, enabling the system to adapt between reducing pressure pulsation and maintaining fuel pressure based on the valve state
2Object-affected harmful factors
If fuel flows through a restricted orifice, then pressure pulsation is attenuated, but fuel flow rate and injection performance deteriorate
Solution Approach 1:
The throttle portion employs a movable part that dynamically adjusts the minimum flow path area based on needle displacement. When the needle opens, the movable part moves to increase flow area, ensuring adequate fuel flow rate. When the needle closes, it restricts the flow area to attenuate pressure pulsation, thus resolving the contradiction between pressure pulsation attenuation and fuel flow rate maintenance
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 design effectively suppresses fuel pressure decrease during opening and reduces pressure pulsation after valve closing, ensuring consistent fuel injection and improved engine performance.
Implementation Method 1
a throttle portion which changes a minimum flow path area of the throttle flow path according to a position of the needle, and allows the fuel to flow without being throttled during the valve opening time, and attenuates the pressure pulsation generated during the valve closing time
Data Source
AI summary
A fuel injection valve includes a nozzle, a housing, a needle, and a throttle portion. The nozzle includes an injection hole through which fuel is injected and a valve seat formed around the injection hole. The nozzle includes an injection hole through which fuel is injected and a valve seat formed around the injection hole. The housing has a fuel flow path through which the fuel to the injection hole flows. One end of the needle is configured to open and close the injection hole by being separated from the valve seat or abutted on the valve seat. The throttle portion is provided upstream with respect to the valve seat in a fuel flow direction.