Internal combustion engine with intake port throttling and exhaust camshaft phase shifting for cylinder deactivation
AssigneeFord Motor Company
InventorWilliam F. Stockhausen
Life of this patent
Estimating the term…
Abstract
A four-stroke cycle, multi-cylinder reciprocating internal combustion engine has a camshaft phaser for powering an exhaust camshaft and for adjusting timing of the camshaft with respect to the rotational position of the crankshaft so that the cylinders of the engine may be deactivated by adjusting the camshaft timing such that the exhaust valves for each cylinder open and close at points which are approximately symmetrical about a rotational position of the crankshaft at which the direction of motion of the pistons change. The controller also closes an intake port throttle during cylinder deactivation.
Claims13
A four-stroke cycle, multicylinder reciprocating internal combustion engine having a crankshaft and a plurality of pistons reciprocably contained within a plurality of cylinders, with said engine further comprising:
- at least one intake popper valve and at least one exhaust popper valve for each engine cylinder;
- a camshaft for operating at least the exhaust valves;
- a camshaft phaser for powering said camshaft and for adjusting the timing of the camshaft with respect to the rotational position of the crankshaft;
- a plurality of intake port throttles, with one of said throttles mounted in proximity to, and upstream of each of said intake valves;
- and
- a controller, connected with said port throttles and said camshaft phaser, for deactivating at least some of the cylinders by operating said camshaft phaser and said port throttles such that for each cylinder which is to be deactivated, the port throttle is closed, and the camshaft timing is adjusted such that the exhaust valve opens and closes at points which are approximately symmetrical about a rotational position of the crankshaft at which the direction of motion of the cylinder's piston changes.
A method for operating a multicylinder, four-stroke cycle reciprocating internal combustion engine on fewer than the maximum number of cylinders, comprising the steps of:
- sensing a plurality of engine and vehicle operating parameters, including at least engine load and engine speed;
- comparing the sensed operating parameters with predetermined threshold values;
- issuing a fractional operation command in the event that the sensed parameters exceed said threshold values;
- closing intake port throttles in each of the cylinders to be deactivated in response to the fractional operation command;
- and
- adjusting the timing of a camshaft which operates popper exhaust valves of the cylinders to be deactivated so that the position of maximum exhaust valve lift is moved from 90.degree. before top dead center on the exhaust stroke to a point at which maximum lift occurs at top dead center of the exhaust stroke.
A four-stroke cycle, multicylinder reciprocating internal combustion engine having a crankshaft and a plurality of pistons reciprocably contained within a plurality of cylinders, with said engine further comprising:
- at least one intake popper valve and at least one exhaust popper valve for each engine cylinder;
- a camshaft for operating at least the exhaust valves;
- a camshaft phaser for powering said camshaft and for timing the camshaft with respect to the rotational position of the crankshaft;
- a plurality of intake port throttles, with one of said throttles mounted in proximity to, and upstream of each of said intake valves;
- and
- a controller for deactivating at least some of the cylinders by operating said camshaft phaser and said port throttles such that for each cylinder which is to be deactivated, the port throttle is closed and the camshaft is adjusted such that the position of maximum exhaust valve lift is moved from 90.degree. before top dead center on the exhaust stroke to a point at which maximum lift occurs either at top dead center of the exhaust stroke, or at bottom dead center of the expansion stroke.
Dependencies are inferred from the claim text.