Caterpillar Inc.

Edward R Gillis

Dan R Ibrahim

Dana Ray Coldren

Charles D Ellenbecker

Junru Azam

Michael D Wesner

Kenneth D Calvert

Houston Weaver, Jr

Harold E Ogg, Jr

Kevin M Scott

Junru He

Engineers have determined that the performance of fuel injectors, including those used in common rail fuel injection systems, can be increased, and undesirable emissions reduced, by controlling the mass flow rate of fuel injected into a combustion chamber during an injection event. While a number of fuel injectors have been developed that have limited rate shaping capabilities, the ability to produce some front end rate shapes has not been possible. In an effort to increase rate shaping capabilities, the present invention includes a valve assembly having at least one valve member that is movable between a plurality of positions to control fluid communication between a number of fluid inlets and outlets.

Valve assembly having multiple rate shaping capabilities and fuel injector using same

This invention relates generally to a piston assembly and more specifically to a piston assembly in a prepackaged configuration. The prepackaged piston assembly is ready for immediate installation into an engine or compressor. The piston assembly has a plurality of rings preinstalled on a piston member and a sleeve position about the piston member and the plurality of rings maintaining the rings in a compressed position ready for installation into an engine. The piston assembly is lowered into a cylinder bore, the sleeve contacts the top surface of a block and the piston assembly can be easily installed into the cylinder bore without the need for the mechanic to compress the plurality of rings. Thus the present invention reduces time and expense required for rebuilding and engine and increases the quality of the rebuild.

Method and apparatus for installing a prepackaged piston assembly in an engine

A nozzle supply valve is positioned in the nozzle supply passage of a fuel injector, and is constructed to generate a boot shaped rate trace mechanically. The goal of the concept is to restrict the flow area during the first boot step and release the flow area restriction in the second step. During the first stage of injection, the flow to the nozzle only goes through a restricted orifice. When the line pressure is high enough to overcome the valve movement pressure spring preload, the nozzle supply valve moves to an unrestricted position, and the boot shaped rate trace is formed. Since this boot shape rate trace is generated mechanically, it can be combined with fuel injectors having a direct control needle valve in order to get different rate traces including, ramps, squares, pilots, posts and other split injections.

Front end rate shaping valve concept for a fuel injection system

In dual fuel engines, it is desirable to have injection of two distinct quantities of liquid fuel. Engines with these operating requirements have typically used two separate fuel injectors, or two separate nozzle assemblies, to satisfy this need. However, these systems can be rather complex and difficult to control. In addition, engineers have learned that fuel injectors having direct control have better performance which can increase engine efficiency. Therefore, the present invention addresses the needs of engines desiring injection of two distinct quantities of fuel, such as dual fuel engines, by utilizing a direct control fuel injector having a dual concentric check having separate orifices for the pilot and main injections.

Fuel injector with directly controlled dual concentric check and engine using same

The present invention relates to fuel injectors having the ability to inject fuel at multiple pressures during an injection event. Traditional fuel injectors used in common rail fuel injection systems and unit pump fuel injection systems typically did not have the ability to inject fuel at multiple pressures during an injection event. However, engineers have learned that increased control over an injection event can lead to improved emissions by the fuel injectors. Therefore, the present invention utilizes an electronically controlled valve member that can direct. the flow of fuel through a fuel injector during an injection event between a relatively restricted passageway and a relatively unrestricted passageway. The present invention finds particular application in both common rail fuel injection systems and electronic unit pump fuel injection systems used in diesel engines.

Fuel injector having dual flow rate capabilities and engine using same

An internal combustion engine includes an engine housing that defines a main combustion chamber separated from a precombustion chamber by a flame communication passage way. A source of gaseous fuel is fluidly connected to one end of a fuel supply passage. A check valve, which includes a valve body with a valve seat, and a valve member, is positioned between the other end of the fuel supply passage and the precombustion chamber. The valve member is moveable between an open position and a closed position. The valve body and the valve member define a fluid passage that fluidly connects the fuel supply passage to the precombustion chamber when the valve member is in its open position. The valve body and the valve member substantially fluidly isolate the valve seat from the precombustion chamber when the valve member is in its closed position.

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Bloomington, IL, United States of America

Edward R Gillis