Fuel Injector Diamagnetic Sleeve Radial Force Stabilization
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Solution Overview
Problem
Existing fuel injectors for combustion engines experience radial forces that cause friction, wear, and instability due to imperfections in the magnetic field, leading to increased production costs and reduced performance over time.
Innovation Solution
A fuel injector with a diamagnetic sleeve positioned radially between the armature and the body, which opposes the external magnetic field, reducing radial forces and allowing the armature to move axially with minimal friction and wear, thereby stabilizing the valve assembly and improving fuel pressure and flow stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If narrow tolerances are used to prevent radial movement of the armature, then radial stability is improved, but production cost increases
Solution Approach 1:
A diamagnetic material is introduced as an intermediary substance between the armature and the solenoid assembly. This diamagnetic material generates a repulsive force that counteracts the radial magnetic forces, stabilizing the armature's radial position without requiring narrow mechanical tolerances, thus resolving the contradiction between radial stability and manufacturing cost
2Stability of the object's composition
If a radial air gap is introduced to reduce magnetic force fluctuations, then radial stability is improved, but the effect is lost when the armature moves radially by a certain amount
Solution Approach 1:
The diamagnetic material serves as a continuous intermediary that maintains stabilizing force even during armature movement and vibration. Unlike a fixed air gap that loses effectiveness when exceeded, the diamagnetic repulsive force dynamically adapts to maintain radial stability under various operating conditions including heavy vibrations
3Device complexity
If radial forces are not compensated, then the structure remains simple, but friction and wear increase leading to early failure
Solution Approach 1:
The diamagnetic material is integrated into the existing solenoid assembly structure, adding minimal complexity while providing continuous radial force compensation. This reduces friction and wear on the armature and valve needle, significantly extending component lifetime without requiring major structural changes
Solution Approach 2:
The magnetic field parameters are modified by introducing the diamagnetic material, which changes the field distribution to include a radial repulsive component. This parameter change compensates for harmful radial forces while maintaining the overall simplicity of the electromagnetic actuation system
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 diamagnetic sleeve effectively cancels out radial forces, reducing wear and friction, increasing the injector's lifetime, lowering production costs, and enhancing the repeatability and stability of fuel injection, while allowing operation at higher fuel pressures.
Implementation Method 1
A diamagnetic material has the property to create a magnetic field in opposition to an externally applied magnetic field. Mounted in a radial direction of the armature, the diamagnetic sleeve may reduce the radial forces of the magnetic field created by the solenoid.
Data Source
AI summary
A fluid injector for a combustion engine has a tubular body which hydraulically connects a fluid inlet end of the injector to a fluid outlet end of the injector. A magnetic core is affixed inside the body, a solenoid is disposed on the outside of the body, and an axially moveable armature is disposed inside the body. A valve assembly controls an axial flow of fluid through the body. The valve assembly has a valve needle to be operated by the armature and a sleeve of diamagnetic material which is located radially between the armature and the body.