Proof of Principle of a Fuel Injector Based on a Magnetostrictive Actuator

Abstract

One of the goals of modern internal combustion engines is the NOx-soot trade-off, and this would be better achieved by a better control of the fuel injection. Moreover, this feature can be also useful for high-performance hydraulic systems. Actual fuel injection technology either allows only the control of the injection time or it is based on very complex mechanical-hydraulic systems, as in the case of piezo-actuators. This work describes the basic steps that brought the authors to the realization of a concept fuel injector based on a Terfenol-D magnetostrictive actuator that could overcome the previous issues, being both simple and controllable. The study provides the design, development, and a feasibility analysis of a magnetostrictive actuator for fuel injection, by providing a basic magneto-static analysis of the actuator, the adaptation of a suitable standard fuel injector, and its experimental testing in a lab environment, with different shapes and amplitude of the reference signal to follow.

Analysis and optimization of nozzle structure parameters of direct-drive giant magnetostrictive injector

“…Based on the structure of the direct-drive giant magnetostrictive injector, the influence of nozzle parameters on the fuel injection performance of the injector was studied by orthogonal test. This paper mainly discusses the influence of needle valve half cone angle deg, needle valve size dn, cavity parameters ds, number of injection holes Ninj, and diameter of injection holes dinj on the displacement and fuel injection rate of the injector, and designs the L16(4 5 ) orthogonal experimental table. The results show that five parameters, such as needle valve half cone angle and needle valve size, have obvious influence on the injector performance, and the cavity parameters are the main influencing factors, and the number of injection holes has the least influence on injection performance.…”

“…In the early stage, the research group designed giant magnetostrictive actuators(GMA) [1][2][3][4][5][6] with giant magnetostrictive material(GMM) [7][8][9] as the transduction material, and designed the direct-drive giant magnetostrictive injector(GMI) [10][11][12][13] by directly driving the needle valve of the injector with GMA.Based on the structure of the direct-drive giant magnetostrictive injector, this paper discusses and analyzes the influence of some structural parameters of the nozzle on the fuel injection performance of the injector, and completes the optimization. As shown in Figure 1, the working principle of the direct-drive giant magnetostrictive fuel injector is as follows: after the power is turned on, the excitation coil generates a magnetic field, and the GMM cylinder stretches under the action of the magnetic field to push the Tshaped rod up, and the needle valve lifts under the action of oil, and the fuel injector starts to inject fuel; After the power is cut off, the GMM cylinder recovers its original length, the T-shaped rod pushes the needle valve downward under the action of the pre-tightening spring, and the injector stops injecting oil.…”

Magneto-Mechanical Enhancement of Elastic Moduli in Magnetoactive Elastomers with Anisotropic Microstructures

“…Magnetizable particles embedded in soft elastomer matrix form a smart rubber composite known as magnetoactive elastomers (MAEs), whose mechanical and rheological properties can be manipulated externally with the magnetic field [1][2][3][4][5][6][7][8][9][10][11][12][13][14]. The ability of controlling mechanical properties externally with an applied magnetic field provides a promising technology for soft robotics and biomedical devices [15,16].…”

Structure Design and Working Characteristics Analysis of Direct-Drive Giant Magnetostrictive Injector

“…In addition, the giant magnetostrictive fuel injector has been actively explored in the literature [ 14 , 15 , 16 , 17 , 18 , 19 , 20 ] and very fruitful results have been achieved.…”