Cummins Engine Company, Inc.

Harold G Weber

John M Mulloy

Patrick F Flynn

Lester L Peters

David A Vittorio

Amarjit S Ghuman

P Douglas Free

Bruce A Watson

Canden R Nelson

An improved turbocharged internal combustion engine is provided having a system and method for preventing a rapid decrease of turbocharger power during rapid fuel reduction transients in engine operation due to reductions in fuel flow rate to the engine. The engine includes a turbocharger power enhancing system including an exhaust valve control device capable of varying the timing of opening of the engine exhaust valves. The turbocharger power enhancing system also includes a processor which generates a control signal when a reduction in the fuel delivery rate is detected. The control signal operates the exhaust valve control device to advance the timing of opening of the exhaust valves to cause additional exhaust gas to be delivered to the turbine thereby preventing a rapid decrease of compressor speed and preventing compressor surge. The system and method may require the presence of one or more other engine operating conditions before the exhaust valve timing may be advanced, such as a minimum intake pressure, a minimum reduction in the fuel rate, a fuel rate reduction within a specific time period and/or an engine speed below a predetermined value.

Turbocharged internal combustion engine with system and method for

An exhaust valve system for an internal combustion engine including a turbocharger is provided for effectively increasing the turbocharged boost pressure at low load engine conditions thereby effectively improving engine transient response. The exhaust valve system includes an exhaust valve control device operable in a normal timing mode for permitting normal opening of one or more exhaust valves at a normal opening crank angle, and in an advanced timing mode for advancing the timing of the opening of the exhaust valve to an advanced opening crank angle prior to the normal opening crank angle while maintaining the timing of normal closing of the exhaust valves at a normal closing crank angle. In one embodiment, the exhaust valve control device includes a tappet and an actuating fluid supply which operate to move the tappet between expanded and collapsed states to advance the opening of the exhaust valve while permitting normal exhaust valve lift to be introduced prior to peak exhaust valve lift thereby maintaining the normal peak lift and the normal timing of exhaust valve closure. In a second embodiment, the exhaust valve control device includes a dedicated advanced timing mode rocker lever capable of selectively actuating one of a pair of exhaust valves to create an early opening exhaust event prior to a normal exhaust event.

Early exhaust valve opening control system and method

A method of forming curvilinear injector spray holes to produce an improved spray from the nozzle tip of a fuel injector is provided. The method uses electrical discharge machining in combination with a novel electrode to form a plurality of curvilinear spray holes in the injector nozzle tip which direct the fuel spray from the nozzle to produce an efficient, enhanced spray. The novel EDM electrode is preferably formed in the configuration of a constant pitch helix having a radius substantially equal to the radius of curvature of the curvilinear spray hole.

Curved hole machining method and fuel injector formed thereby

A turbomachine, operable as a compressor or a turbine, for a compressible fluid is provided which includes a wheel having a plurality of vanes extending from a generally axial flow section to a generally radial flow section. Adjacent vanes define fluid passageways having a generally axially oriented section and a generally radially oriented section. Located substantially within the generally radially oriented sections of a predetermined number of passageways is a reference station which has a configuration such that the mean tangential dimension of said passageway at said reference station is no more than about 60% of the circumference of the rotor at that mean radius divided by the number of vanes at that radius. Each reference station serves to effect substantial attachment of the flowing fluid to the surfaces defining said passageway, particularly at low mass flow, and, thus, broaden the usable flow range of the turbomachine. A rounded vane end at the wheel periphery further serves to enhance said attachment.

Turbomachine

A turbomachine for a compressible fluid is provided which includes a compressor wheel having a plurality of vanes extending from a generally axial flow inlet to a generally radial flow outlet. Adjacent vanes define fluid passageways having a generally axially oriented section near the inlet and a generally radially oriented section near the outlet. Located substantially within the generally radially oriented sections of a predetermined number of passageways is a reference station which has a configuration such that the mean tangential dimension of said passageway at said reference station is no more than about 60% of the circumference of the rotor at that mean radius divided by the number of vanes at that radius. Each reference station serves to effect substantial attachment of the flowing fluid to the surfaces defining said passageway, particularly at low mass flow, and, thus, broaden the usable flow range of the compressor.

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Columbus, IN, United States of America

Harold G Weber