Abstract: A fuel injector for use in a internal combustion engine is disclosed. The fuel injector includes a body having a discharge end and a longitudinal axis extending therethrough, and an electromagnetic coil located within the body. The fuel injector further includes a fuel metering valve operable between an open position and a closed position and an air metering valve operable between an open position and a closed position. The fuel injector also includes a valve seat located within the body proximate to the discharge end and includes an orifice extending therethrough along the longitudinal axis. A needle is reciprocally mounted along the longitudinal axis between an open position and a closed position. The needle has an upstream end, a downstream end, and a needle channel extending therethrough along the longitudinal axis. The needle engages the valve seat in the closed position. A guide is disposed along the longitudinal axis such that the upstream end of the needle is reciprocable within the guide.

Abstract: A fuel injector having a pulsed air assist atomizer to provide improved atomization and fuel spray targeting. The fuel injector provides a pulsed air supply, rather than a continuous air supply at the discharge of the fuel injector. The fuel injector includes an air inlet, a fuel inlet, mixing chamber and controller for controlling the simultaneous introduction of air and fuel into the mixing chamber. The controller controls an air jet to impact fuel flowing into the mixing chamber to atomize the fuel before discharge of the air-fuel mixture from the fuel injector.

Abstract: A fuel injector has a shroud surrounding its valve orifice. The shroud carries a porous element spaced from the orifice to define a chamber. Air passages are provided through the shroud for injecting air under pressure into the chamber. The fuel sprayed onto the porous element from the orifice enters the pores of the element and increases the wetted surface area such that the air under pressure passing through the porous element shreds the fuel films and finely atomizes the fuel for egress from the porous element into the internal combustion engine.

Abstract: An improved atomization fuel injector for an internal combustion engine includes an armature assembly including an injector needle reciprocable between a closed position and an open position; a needle seat for receiving the injector needle in the closed position, the needle seat including a central opening therethrough; an exit orifice disk disposed downstream of the needle seat; and an impinging jet atomizer disposed upstream of the exit orifice disk. A method of improving atomization of fuel in fuel injectors includes providing a fuel injector; adding fuel to the fuel injector; passing the fuel through a central opening in a seat of the fuel injector; separating the fuel into at least two channels; and directing at least two channels of fuel towards one another such that the channels of fuel collide with each other.

Abstract: An injector needle/armature assembly stroke is controlled so as to minimize opening and closing impact forces. The controlled motion eliminates or significantly reduces the problems associated with valve bounce, providing less acoustic emission, reduced wear, improved spray characteristics and better flow regulation. The current applied to the electromagnetic coil of the injector in accordance with a modified injector timing pulse waveform serves to reduce impact velocities at each end of the armature stroke. The waveform can be optimized for a class of injectors with a pulse width modulated waveform, repeatedly re-energizing and de-energizing the electromagnetic coil in accordance with an optimized on/off pulse train.

Abstract: A flow straightener and a controlled disturbance element are interposed between the injector needle seat and the discharge orifice disk of a fuel injector. The flow straightener straightens flow eliminating turbulence prior to fuel discharge. The controlled disturbance disturbs the fuel flow providing controlled atomization. A spacer is provided between the flow straightener and the controlled disturbance element as well as between the controlled disturbance element and the discharge orifice disk delimiting flow recovery regions. By varying the diameter and/or height of the spacers, in conjunction with the controlled disturbance element, an adjustable level of flow disturbance can be obtained, leading to variable degrees of atomization. In one arrangement, the flow straightener and the controlled disturbance element are combined into a single flow element performing the functions of both the flow straightener and the controlled disturbance element.

Abstract: Opening and closing times of a fuel injector are accurately determined in accordance with the energy content of an accelerometer trace. The energy content of an accelerometer trace is determined in accordance with a predetermined relation. A line is defined between known points prior to and after the opening or closing time. The normal distance between the line connecting known points and the accelerometer trace energy content is maximum at the inflection point, which corresponds to the opening or closing time. With this data, an ECU can be properly programmed to more accurately control an injector stroke, thereby improving engine performance.

Abstract: A fuel injector for an engine includes a fuel volume having an air inlet port having a porous membrane. The membrane is permeable to air and impermeable to fuel whereby air inlet to the fuel volume forms a two-phase air bubble/fuel dispersion within the fuel volume. Upon actuation of the needle valve of the injector, this two-phase air bubble/fuel dispersion flows through the orifice into the engine whereby improved atomization, burn and fuel economy with resultant reduction in emissions are provided.

Abstract: The fuel and air supply system of the present invention provides fuel from a fuel pump at a first pressure upstream of a pressure reducer, fuel being provided directly to the fuel injector at a reduced pressure on the downstream side of the pressure reducer. A bypass line in communication with the fuel line upstream of the pressure reducer provides fuel to an air reservoir at the first pressure. The air reservoir lies in communication with a porous member(s) in the fuel injector in an air inlet to a fuel volume within the injector upstream of the pressure reducer. Upon flow of fuel into the air reservoir and closure of normally open fuel and air valves in the reservoir, air at the first pressure is supplied the porous member(s), creating a pressure differential across the member(s), causing air to flow through the porous member(s) to form air bubbles in the fuel volume for two-phase flow through the fuel injector orifice.

Abstract: Multiple orifice disks are stacked and include one or more swirl disks. The effect of the stack of disks is to impart swirl to the fuel stream being ejected from the injector in a relatively short axial length. The geometry of the disks in the stack are such that the fuel from the top disk enters the bottom disk at the end of a pattern which operates to impart a swirl component to the fuel. The pattern in the bottom disk is typically a two layered pattern wherein the top layer is one half the thickness of the thin disk and the bottom layer is the second half of the thickness of the thin disk.

Abstract: The atomizer is a cap-shaped shroud that contains a stack of flat stamped metal inserts. When assembled onto the nozzle of a fuel injector, the atomizer causes the inserts to be axially sandwiched between the shroud's end wall and the exterior end of the nozzle. In the zone of sandwiching, the inserts have circumferential discontinuities that in cooperation with the nozzle end and the shroud's end wall define air assist openings for the assist air to flow radially inwardly toward the injected fuel that has just been injected from the nozzle. An air assist opening in one insert is thereby both circumferentially and axially offset from an air assist opening in another insert.