Method and apparatus for fuel injection in an internal combustion engine, and internal combustion engine
AssigneeScania CV AB (publ)
InventorsAnders Hultquist, Christer Hedström
Life of this patent
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Abstract
A method for injection of fuel into a cylinder for a combustion engine is distinguished by the fact that the fuel is injected into the cylinder in the region (10) of the piston's upper dead centre point (8) in the gas exchange stroke (4, 5), when the fuel is injected into the hot exhaust gases in order readily to be able to be vaporised and form a homogenous fuel/air mixture which can be ignited by compression the next time the piston approaches the upper dead centre position. The invention relates also to an arrangement for implementing the method and an engine incorporating such arrangement.
Claims23
A method for operating an ATAC engine, wherein there is a piston which is movable in a cylinder to an upper dead center point of the piston and is movable down from the upper dead center point, the method comprising the steps of:
- moving the piston through the cylinder in a plurality of piston strokes, including a compression stroke to the upper dead center point of the piston;
- allowing the fuel to self-ignite after the compression stroke;
- thereafter moving the piston through a down stroke caused by the ignition;
- thereafter moving the piston through an exhaust stroke to the upper dead center point of the piston;
- thereafter moving the piston through an intake stroke, the exhaust stroke and the intake stroke together constituting a gas exchange stroke;
- and
- inserting air and injecting substantially all the fuel into the cylinder in the region of the upper dead center point of the piston during the gas exchange stroke to mix the fuel with the air.
An ATAC engine comprising:
- a plurality of cylinders each having a piston movable therein, and each including an intake valve, an exhaust valve and a fuel injector
- the valves being operative in relation to movement of the piston to define a plurality of piston strokes, including:
- a compression stroke to the upper dead center point of the piston, followed by
- a working stroke resulting from ignition of fuel at the end of the compression stroke, followed by
- an exhaust stroke to the upper dead center point of the piston, followed by
- an intake stroke,
- the exhaust stroke and the intake stroke together constituting a gas exchange stroke,
- the intake valve being operative to admit air to the cylinder during the intake stroke;
- and
- a controller for the fuel injector operative to inject substantially all the fuel into the cylinder in the region of the upper dead center point of the piston during the gas exchange stroke to mix the fuel with the air admitted through the intake valve,
- whereby the fuel-air mixture in the cylinder self-ignites at the end of the compression stroke.
Dependencies are inferred from the claim text.