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LIQUID FUEL INJECTION NOZZLE UTILIZING AN OUTWARD OPENING POPPET VALVE (OOPV)

IP.com Disclosure Number: IPCOM000193280D
Publication Date: 2010-Feb-17
Document File: 8 page(s) / 379K

Publishing Venue

The IP.com Prior Art Database

Abstract

A fuel injection nozzle utilizing an outward-opening poppet valve (OOPV) used to inject liquid fuel into the working cylinder(s) of a reciprocating compression ignition engine is disclosed. The proposed technique utilizes the elastic resilience of the poppet valve stem to control the lift of the valve in response to fuel injection pressure. The use of an OOPV nozzle improves air-to-fuel mixing and air-utilization in the cylinder as compared to multi-hole injection nozzle systems.

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RP13311

LIQUID FUEL INJECTION NOZZLE UTILIZING AN OUTWARD OPENING POPPET VALVE (OOPV)

BRIEF ABSTRACT

    A fuel injection nozzle utilizing an outward-opening poppet valve (OOPV) used to inject liquid fuel into the working cylinder(s) of a reciprocating compression ignition engine is disclosed. The proposed technique utilizes the elastic resilience of the poppet valve stem to control the lift of the valve in response to fuel injection pressure. The use of an OOPV nozzle improves air-to- fuel mixing and air-utilization in the cylinder as compared to multi-hole injection nozzle systems.

KEYWORDS

    Outward-opening poppet valve (OOPV), liquid fuel, reciprocating compression ignition engines, multi-hole injection nozzles, valve stem.

DETAILED DESCRIPTION

    Fuel injection is a system for mixing fuel with air in an internal combustion engine. The injector needs to withstand the temperature and pressure inside the cylinder and deliver the fuel in a fine mist. Circulation of the mist so that it is finely distributed is an important factor. Some diesel engines employ special induction valves, pre-combustion chambers or other devices to swirl the air in the combustion chamber or otherwise improve the ignition and combustion process.

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RP13311

    A poppet valve consists of a hole, which is usually round or oval and a tapered plug which is usually a disk shape on the end of a shaft which is also called a valve stem. Poppet valves are used in most piston engines to open and close the intake and exhaust ports in the cylinder head.

    In reciprocating compression-ignition engines like diesel engines, the charge air is compressed during the compression stroke of the piston. Fuel is injected into the hot compressed air in the cylinder at a time during the working cycle when it is advantageous for engine performance. Liquid fuel injected into the cylinder forms a heterogeneous mixture consisting of liquid fuel droplets, evaporated fuel and air. This mixture ignites when the local air-to-fuel ratio and temperature are within flammability limits. Due to the need to produce power efficiently, there is relatively little time available for the fuel to mix with the air before it ignites and while it is burning. This type of combustion generates relatively high levels of nitrous oxides and particulate matter in the exhaust. Therefore, there is a need to improve the system with respect to the time taken and the degree to which the fuel mixes and evaporates in the air. Moreover, a more homogeneous mixture will help in reducing emissions and fuel consumption.

    Usually, liquid fuel is injected into the cylinder at high pressure (up to 1800 bar) through multi-hole fuel injectors. In these injectors, an inward opening needle valve upstream of the spray holes controls the on-off supply of the fuel to the cylinder. The needle valve is typically pre-loaded by a coil spring and it moves between fixed stops so that it is fully open during injection events. The controllin...