Engine valve actuation for combustion enhancement
AssigneeWisconsin Alumni Research Foundation
InventorsRolf Deneys Reitz, Christopher J. Rutland, Rahul Jhavar
Life of this patent
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Abstract
A combustion chamber valve, such as an intake valve or an exhaust valve, is briefly opened during the compression and/or power strokes of a 4-stroke combustion cycle in an internal combustion engine (in particular, a diesel or CI engine). The brief opening may (1) enhance mixing withing the combustion chamber, allowing more complete oxidation of particulates to decrease engine emissions; and/or may (2) delay ignition until a more desirable time, potentially allowing a means of timing ignition in otherwise difficult-to-control conditions, e.g., in HCCI (Homogeneous Charge Compression Ignition) conditions.
Claims48
A method for modifying combustion in a combustion chamber of a 4-stroke internal combustion engine running under standard warm engine operating temperatures, the method comprising the step of briefly opening a combustion chamber valve sometime during a period spanning:
- a. the latter half of the compression stroke, and
- b. the first half of the power stroke.
A method for modifying combustion in a combustion chamber of a 4-stroke internal combustion engine running under standard warm engine operating temperatures, the method comprising the step of opening a combustion chamber valve during at least one of the compression stroke and the power stroke, with such opening effecting an escape of no more than approximately 15% of the mass of the combustion chamber contents.
A method for modifying combustion in a combustion chamber of a 4-stroke internal combustion engine running under standard warm engine operating temperatures, the method comprising the step of opening a combustion chamber valve for at least one discrete period, each period:
- a. starting and ending sometime between the start of the compression stroke and the end of the power stroke, and
- b. effecting an escape of no more than 20% of the mass of the combustion chamber's contents.
Dependencies are inferred from the claim text.