Spark-Ignition Direct Fuel Injection Valve Geometry
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Solution Overview
Problem
Fuel injection valves for gasoline engines face issues with fuel adhesion to the suction valve and inner cylinder walls due to long fuel spray lengths, which affect engine output and fuel economy.
Innovation Solution
A spark-ignition direct fuel injection valve with fuel injection holes having an inwardly open inlet and outwardly open outlet, featuring a first round-chamfered portion on the inlet edge and an extending length not exceeding three times the hole diameter, to control fuel injection and reduce fuel adhesion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If fuel injection speed is increased to make fuel particles finer, then fuel spray characteristics are improved, but fuel spray length becomes too long causing fuel adhesion to suction valve and cylinder walls
Solution Approach 1:
The patent changes the geometric parameters of the injection hole, specifically setting the extending length L to not exceed three times the hole diameter D (L≤3D). This parameter optimization controls the fuel spray length to prevent adhesion while maintaining fine fuel particle generation through appropriate injection speed.
Solution Approach 2:
The patent introduces a round-chamfered portion at the inlet edge of the injection hole, creating a curved transition surface. This curvature modification improves fuel flow characteristics and helps control spray patterns to reduce adhesion while maintaining effective atomization.
2Manufacturing precision
If fuel injection hole extending length is increased to improve spray characteristics, then fuel atomization is enhanced, but fuel spray length increases causing adhesion problems
Solution Approach 1:
The patent optimizes the extending length parameter L of the injection hole to satisfy L≤3D (where D is the hole diameter). This parameter change achieves the balance between sufficient fuel atomization and controlling spray length to prevent adhesion to engine components.
Solution Approach 2:
The patent applies a round-chamfered portion at the injection hole inlet, providing a partial geometric modification that enhances fuel flow and atomization without requiring excessive lengthening of the injection hole, thus avoiding adhesion problems.
3Ease of operation
If round-chamfered portion is added to injection hole inlet to improve fuel flow, then fuel injection control is enhanced, but device complexity increases
Solution Approach 1:
The patent adds a round-chamfered portion at the injection hole inlet, creating a curved transition surface that improves fuel flow control and injection characteristics. This geometric feature enhances operational control while remaining a simple machining modification rather than a complex structural addition.
Solution Approach 2:
The round-chamfered portion modifies the inlet geometry parameters of the injection hole, providing improved fuel flow control through controlled curvature and transition angles, achieving better injection characteristics with minimal structural complexity.
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 suppresses fuel adhesion to the suction valve and inner cylinder walls, reducing fuel spray length and improving engine performance by managing fuel flow and injection speed.
Implementation Method 1
an opening edge of the injection hole inlet has a first round-chamfered portion formed on an upstream side with respect to a fuel flow toward the injection hole inlet
Implementation Method 2
a valve body which controls fuel injection from the injection hole by contacting and separating from the valve seat
Data Source
AI summary
A spark-ignition direct fuel injection valve includes, at least, a seat member provided with a fuel injection hole and a valve seat and a valve body which controls fuel injection from the injection hole by contacting and separating from the valve seat. In the spark-ignition direct fuel injection valve: the injection hole has an injection hole inlet which is open inwardly of the seat member and an injection hole outlet which is open outwardly of the seat member; an opening edge of the injection hole inlet has a first round-chamfered portion formed on an upstream side with respect to a fuel flow toward the injection hole inlet; and an extending length (L) of the injection hole does not exceed three times a hole diameter (D) of the injection hole.