Exhaust gas reprocessing/recirculation with variable valve timing
AssigneeCaterpillar Inc.
InventorsJames J. Faletti, Steven J. Funke
Life of this patent
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Abstract
Apparatus and method, particularly suited for a work machine, provides EGR to an internal combustion engine without the addition of special EGR hardware. The invention provides a controlling of a timing of the closing of a first exhaust valve during the exhaust stroke of a first cylinder to trap exhaust gas in the first cylinder for mixing with combustion air in the first cylinder during the intake stroke.
Claims14
A work machine having a frame, said work machine comprising:
- an internal combustion engine attached to said frame;
- a block being a part of said internal combustion engine, said block defining a plurality of combustion cylinders, said plurality of combustion cylinders having a first cylinder having at least an exhaust stroke and an intake stroke;
- a cylinder head being a part of said internal combustion engine, said cylinder head being in fluid communication with said first cylinder, said cylinder head having a first exhaust valve corresponding to said first cylinder and a first intake valve corresponding to said first cylinder;
- an intake manifold being a part of said internal combustion engine, said intake manifold being fluidly connected to said plurality of combustion cylinders to supply combustion air thereto;
- an exhaust manifold being a part of said internal combustion engine, said exhaust manifold being fluidly connected to said plurality of combustion cylinders to receive exhaust gas therefrom;
- and
- an apparatus which controls a timing of the closing of said first exhaust valve during said exhaust stroke of said first cylinder to trap exhaust gas in said first cylinder for mixing with said combustion air in said first cylinder during said intake stroke, said apparatus controlling an opening and a closing of one of said first intake valve during said exhaust stroke of said first cylinder and said first exhaust valve during said intake stroke of said first cylinder.
An internal combustion engine, comprising:
- a block defining a plurality of combustion cylinders, said plurality of combustion cylinders having a first cylinder having at least an exhaust stroke and an intake stroke;
- a cylinder head in fluid communication with said first cylinder, said cylinder head having a first exhaust valve corresponding to said first cylinder and a first intake valve corresponding to said first cylinder;
- an intake manifold fluidly connected to said plurality of combustion cylinders to supply combustion air thereto;
- an exhaust manifold fluidly connected to said plurality of combustion cylinders to receive exhaust gas therefrom;
- and
- an apparatus which controls a timing of the closing of said first exhaust valve during said exhaust stroke of said first cylinder to trap exhaust gas in said first cylinder for mixing with said combustion air in said first cylinder during said intake stroke, said apparatus controlling an opening and a closing of one of said first intake valve during said exhaust stroke of said first cylinder and said first exhaust valve during said intake stroke of said first cylinder.
A method for providing EGR in an internal combustion engine having a first cylinder having at least an exhaust stroke and an intake stroke, a first exhaust valve corresponding to said first cylinder, and a first intake valve corresponding to said first cylinder, comprising the steps of:
- controlling a timing of the closing of said first exhaust valve during said exhaust stroke of said first cylinder to trap exhaust gas in said first cylinder;
- controlling a timing of an opening and a closing of one of said first intake valve during said exhaust stroke of said first cylinder and said first exhaust valve during said intake stroke of said first cylinder;
- and
- mixing said exhaust gas trapped in said first cylinder with combustion air in said first cylinder during said intake stroke.
Dependencies are inferred from the claim text.