Lucas Industries Public Limited Company

Lucas Industries Limited

David J Gaskell

John W Stevens

In a multi-hole fuel injector of the VCO type the holes are larger at their inner ends than their outer ends, i.e. they taper in some way, to achieve a bushy spray without making the wall of the nozzle too thin. They can best be formed by electro-erosion machining.

Method of making fuel injectors for internal combustion engines

A deformable electrode for electrochemical machining (ECM) of passages, in particular curved passages or passage sections in workpieces, is constructed from a deformable, electrically insulating tube having electrically conductive electrode tip means arranged around the end of the tube to form the working tip of the electrode. Electrical conductor means are connected to the electrode tip means and extend along the tube. During ECM of a passage an electrolyte solution is supplied along the center of the tube, and a voltage is applied between the workpiece the electrode tip means, via the conductor means, so that dissolution of the workpiece occurs near the electrode tip means at the working face of the passage being machined.

Method and electrode for forming passages in workpieces

Fuel injectors for internal combustion engines

A clamp for a fuel injection nozzle of an internal combustion engine includes a beam element which is forked at one end for engagement with surfaces on the nozzle and at its other end engages a reaction member. Intermediate its ends the beam element is apertured to receive a threaded member engaged with the cylinder head of the engine whereby the nozzle is clamped in a bore in the cylinder head. The beam element is formed from strip material and is dimensioned so that the force which can be applied to the nozzle is limited by the elastic deformation of the beam element.

Clamping arrangement

A fuel injection nozzle comprises a valve member which is biased into contact with a seating by a spring supported on a spring abutment having an integral extension which projects through an aperture in the end face of a holder which carries a nozzle body in which the valve member is located. The valve member is in engagement with the extension. A sleeve surrounds the valve member and is slidable in the body and is engageable with the extension. The valve member and the sleeve move together against the action of the spring under the action of fuel pressure to allow fuel flow to an outlet. The movement of the sleeve is arrested by a stop surface defined by the end face of the holder. The continued movement of the valve member being under the action of the fuel pressure acting on the valve member alone, until its movement is arrested by a stop.

Fuel injection nozzle

A fuel injection nozzle of the inwardly opening type has a valve member which is movable against the action of a spring by fuel under pressure to allow fuel flow through an outlet. The valve member is coupled to a piston which is slidable within a cylinder formed in a part. The cylinder forms a damping chamber from which there is a leakage path and the part is axially adjustable to determine the degree of restriction.

A fuel injection nozzle for an internal combustion engine includes a valve member which is slidable in a nozzle body. The body is provided with a bore in which is formed a seating and to support the valve member there is provided a sleeve which is an interference fit within a wider portion of the bore. Fuel under pressure is conveyed by grooves defined on the outer surface of the sleeve from a nozzle inlet and the fuel flows from the grooves through slits formed in the sleeve, to a space defined between the valve member and the bore. The pressure of fuel acts on the valve member to lift the valve member from the seating and the slits are sufficiently narrow to retain particles of dirt entrained in the fuel.

Fuel injection nozzles

A fuel injection nozzle of the inwardly opening type includes a valve member which is biased into contact with a seating by a spring. The valve member is surrounded in part by a sleeve and both the valve member and sleeve are subject to fuel pressure so that axial forces are produced which act in opposition to the spring. When the forces are large enough the valve member and sleeve move but the sleeve movement and hence the movement of the valve member, is limited by a stop. Fuel is allowed to flow through an outlet at a restricted rate and only when the fuel pressure rises is the valve member moved further to allow unrestricted flow of fuel. The further movement of the valve member is limited by the engagement of an abutment on the valve member with the end of the sleeve.

A fuel injection nozzle for supplying fuel to a compression ignition engine includes a valve member movable against a spring to allow fuel flow through an outlet from a fuel inlet passage. The valve member is actuated by the pressure of fuel and the nozzle includes a flow path extending from said inlet passage to a drain. The flow passage includes a variable restrictor defined by a port and the valve member, the degree of restriction to the flow of fuel increasing as the valve member moves against the action of the spring.

A fuel injection nozzle for supplying fuel to an internal combustion engine comprises an inwardly opening valve member which is urged by fuel under pressure against the action of a spring to allow fuel flow through an outlet opening. The valve member is surrounded by a sleeve member which is also subjected to the fuel pressure and engages the valve member to assist the initial movement thereof. The sleeve is slidable in a bore and the valve member in the sleeve. The working clearance between the wall of the bore and the sleeve and between the sleeve and the valve member are interconnected by radial bores or by making the sleeve from porous material such as sintered material.

Injection nozzle

A fuel injection nozzle has a valve member which is axially movable within a bore in a nozzle body. It is resiliently urged into contact with a seating at one end of the bore and carries an extension which projects with clearance through an opening at said one end of the bore. Intermediate the ends of the bore is an enlargement to which fuel under pressure can be supplied and the portions of the bore between the enlargement and the other end of the bore tapers inwardly from the enlargement to allow the extension to partake of sideways movement within the opening to minimize the risk of carbon deposit forming in the opening and on the extension.

A fuel injection nozzle of the inwardly opening type has a valve member which is slidable within a bore to control fuel flow through an outlet. Fuel under pressure from an inlet is supplied to an enlargement to act upon the valve member to lift the valve member against spring pressure and the fuel can flow to the enlargement by way of two flow paths the first of which includes a groove on the valve member and a first port in the wall of the bore. The port is positioned so that increasing restriction to the flow of fuel to the outlet occurs as the valve member lifts. The second flow path includes the groove and a second port which opens to the groove after a predetermined movement of the valve member. The initial movement of the valve member under the action of increasing fuel pressure at the inlet is thus controlled.

A fuel injection nozzle for supplying fuel to an internal combustion engine is of the so-called outwardly opening type and has a valve head located in a pocket the wall of which is of right cylindrical form. A circumferential groove is formed in the wall of the pocket and fuel is communicated thereto by a further groove or grooves on the valve head. The valve head forms a first outlet communicating with the circumferential groove and through which on the initial lift of the valve head fuel flows to produce a low penetration fuel spray. As the head is further lifted ports in the valve head are exposed to the groove and these ports communicate with a central outlet in the head. A penetrative jet of fuel issues from the central outlet.

A fuel injection nozzle assembly includes an outwardly opening valve member having a stem about which is located a spring abutment engaged by a spring. The stem is provided with an enlarged portion adjacent a reduced portion and a collar abuts against the abutment. The collar has an aperture in which is defined a recessed part annular shoulder which is engaged by the enlarged portion of the stem. The collar has a further aperture which breaks into the recessed aperture, the further aperture being large enough to allow the enlarged portion to pass therethrough and the gap defined between apertures is large enough to allow the reduced portion of the stem to be passed therethrough.

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Sudbury, United Kingdom

David J Gaskell