Cummins Engine Company, Inc.

Dennis M Ashwill

Lester L Peters

A S Ghuman

J P Perr

B M Yen

Julius P Perr

Bradlee J Stroia

John D Lane

Benjamin M Yen

Mark S Cavanagh

Russ P Durrett

Chung Y Liu

Chad L Buchanan

Chris Sorg

Donald N Case

A swirl tip injector nozzle housing is provided for a fuel injector which includes a fuel atomization enhancing feature for creating effective fuel atomization and breakup during discharge from the injector. The fuel atomization enhancing feature includes a plurality of curvilinear spray holes having an angle of curvature equal to approximately 90 degrees. Fuel flowing from the inlet of each spray hole to the outlet is induced, by the 90 degree angle of curvature, to flow through a tangential flow path or swirl within the spray hole causing rapid spreading and breakup of the fuel jet spray upon exiting the outlet of the spray hole. The fuel atomization enhancing feature may also include positioning each spray hole so as to extend orthogonally from the interior surface of the fuel cavity to create optimal entry of the fuel into the tangential flow path.

Swirl tip injector nozzle

An injection rate shaping nozzle assembly for a fuel injector is provided which includes a closed nozzle valve element and a rate shaping control device including an injection spill circuit for spilling a portion of the fuel to be injected to produce a predetermined time varying change in the flow rate of fuel injected into a combustion chamber. The spill circuit includes a spill passage integrally formed in the nozzle valve element. The rate shaping control may include a spill valve for controlling the spill flow through the spill circuit to create a low injection flow rate followed by a high injection flow rate. The spill passage may communicate with the injector nozzle cavity between injection events or alternatively may be blocked to prevent spill flow between injection events. The rate shaping control device may include a spill accelerating device in the form of a spill chamber formed in the nozzle valve element for creating a rapid increase in the spill flow rate. In another embodiment, the rate shaping device may include a throttling passage integrally formed in the nozzle valve element to vary the rate at which fuel pressure in the nozzle cavity increases so as to vary the flow rate through the injector orifices.

Injection rate shaping nozzle assembly for a fuel injector

A fuel injection rate shaping control system is provided which effectively controls the flow rate of fuel injected into the combustion chamber of an engine to improve combustion and reduce emissions by controlling the rate of pressure increase during injection. The injection rate shaping control system includes a rate shaping control device including a rate shaping transfer passage having a predetermined length and diameter specifically designed to create a desired injection pressure rate shape. In other embodiments of the present invention, two or more rate shaping transfer passages capable of producing distinct rate shapes are packaged in various fuel injection systems to selectively provide various rate shapes depending on operating conditions. Switching valves, i.e., solenoid operated three-way valves, may be used to direct the fuel or timing fluid flow to any one of the rate shaping transfer passages. Also, a dampening means in the form of a reverse flow restrictor valve is positioned in the rate shaping transfer passage to dampen reflected pressure waves thereby minimizing the adverse effects thereof.

Fuel injection rate shaping control system

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Columbus, IN, United States of America

Dennis M Ashwill