US 6,427,643 B1 · Internal combustion engine with variable compression ratio

Abstract

A lean burn auto-ignition internal combustion engine which has a combustion volume which includes two parts one entering into the other, the volume of the second part being variable by control means (34) which takes into account the various operating parameters of the engine to ensure that auto-ignition takes place at a time which ensures maximum benefit from the ignited fuel charge. In a piston engine there is a secondary cylinder (30) and piston (31) entering into the main cylinder (10), the piston in the secondary cylinder being continuously movable to vary the compression ration of the combustion volume defined by the two pistons (11, 31) so that ignition takes place at a position of the movement of the main piston to ensure maximum utilization of the power generated by the ignited charge.

Claims35

Dependent claims

A method for operating an internal combustion auto-ignition engine utilizing a fuel/air mix, comprising the steps of:

providing said internal combustion auto-ignition engine with combustion volumes each having a compression ratio so that the fuel/air mix auto-ignites;
varying an ignition point of the fuel/air mix by dynamically modifying the compression ratio of each said combustion volume of said internal combustion auto-ignition engine, so that auto-ignition commences at a pre-determined point during an engine cycle, the combustion of the fuel occurring so that pressure in each said combustion volume, due to the combustion of the fuel, increases for ensuring that the pressure generated thereby acts during a power stroke of said internal combustion auto-ignition engine.

An internal combustion auto-ignition engine utilizing a fuel/air mix, comprising:

at least one combustion volume having a compression ratio so that a fuel/air mix is capable of auto-igniting;
and,
means for varying an ignition point of the fuel/air mix by dynamically modifying the compression ratio of each said combustion volume of said internal combustion auto-ignition engine, so that auto-ignition commences at a pre-determined point during an engine cycle, the combustion of the fuel occurring so that pressure in each said combustion volume, due to the combustion of the fuel, increases for ensuring that the pressure generated thereby acts during a power stroke of said internal combustion auto-ignition engine, said means for varying an ignition point of the fuel/air mix further including a secondary volume and a secondary volume-varying element, along with means for altering position of said secondary volume-varying element, so that the auto-ignition occurs at a required position under particular environmental and internal engine conditions.

Dependencies are inferred from the claim text.

Internal combustion engine with variable compression ratio

Life of this patent

Internal combustion engine with variable compression ratio

Life of this patent

Abstract

Claims35