Affiliations: [a] School of Electrical and Computer Engineering, RMIT
University, GPO Box 2476V, Melbourne, VIC 3001, Australia | [b] School of Aerospace, Mechanical and Manufacturing
Technology, RMIT University, GPO Box 2476V, Melbourne, VIC 3001,
Australia
Abstract: The aim of this investigation was to develop a specific modelling
approach capable of reducing the size of the fuel injector solenoid device
while improving its response time and attraction force. Several developed
modelling and simulation procedures have focused on various aspects of solenoid
component modifications in order to develop an evolution process of
miniaturising a fuel injector solenoid, using the latest finite element method
(FEM) tool software. The specific factors that influenced the optimum operation
of the fuel injector solenoid were the geometrical shape of individual solenoid
components, material properties, air-gap constraints, boundary conditions,
current source conditions, mass constants, and damping coefficients of the
plunger. The attraction force distribution in the main air-gap was directly
influenced by the taper angle of the 2D and 3D plunger pole faces, plunger
length and the permanent magnetism. The precise definition of the
electro-mechanical motion of plunger was of enormous importance in reducing the
fuel injector solenoid response time, closely related to stroke and mass of the
plunger, spring characteristics, motion and rebound of the plunger. Using the
developed approach, the initial size of the fuel injector has been reduced by
35%, the attraction force increased by 26% and the response time reduced
by 76%. However, by frequently repeating the design trials and conducting a
thorough experimental investigation, the final minimum response time was
achieved by the virtual rebound delay model. The reduction in response time
from the 'optimal' experimental to virtual model was by 35%. The simplicity
and effectiveness of the developed methods, allowed for quick and accurate
evaluation.
