US 8,082,908 B2 · 2-valve, 2-plug, 2-intake lean burn engine with squish flow with about 2/3 the combustion chamber under the exhaust valve

Abstract

An ignition-engine system for internal combustion engines having two-valves per cylinder (100) with a larger intake valve (103) and a smaller exhaust valve (104) in a longitudinal layout with a single camshaft (118) operating bucketed valve stems 103a and 104a that are vertical, with the valves making up essentially the roof of the combustion chamber and having a volume essentially under the intake valve of approximately 35% of the combustion chamber and a volume under the exhaust valve of approximately 65%, and two spark plugs per cylinder with plugs (102a) and (102b) located at the edge of two opposite squish-zones (105) of a compact combustion chamber, wherein the air-flow near TC is channeled between the two large squish-lands (101a) and (101b) wherein the cross-section of the channel is approximately constant of average width “W’, resulting in a relatively more compact combustion chamber having squish-lands take up approximately ⅓ of the projected bore area of the cylinder and the more compact channel to be approximately ⅔ of the bore area, wherein as the piston approaches ignition it provides an approximately orthogonal-to-the-main-flow (109) through the action of the squish walls which have a clearance of only about 0.06 inches with the piston at top center for improving knocking by moving the spark-flame kernel toward the hotter exhaust valve.

Claims5

Dependent claims

A variable air-fuel ratio (AFR), lean burn internal combustion (IC) engine system for igniting, combusting, and expanding a burnt air-fuel mixture and producing work comprising:

a movable piston within a cylinder that has a cylinder head with single intake and single exhaust valve openings with the combustion chamber located mainly in the head, and wherein the exhaust valve stem is vertical (with the exhaust valve horizontal) and has approximately 65% of the combustion chamber volume in a cup-like volume essentially under the exhaust valve comprising part of the roof of the combustion chamber, and the intake valve comprises an element subtending from the roof to near the intersection of the cylinder wall and the piston at top center (TC) to make a triangular shape, and further including two squish lands for producing high squish-flow and turbulence as the piston nears TC on the engine compression stroke, the system constructed and arranged to have two spark plugs positioned and oriented such that as the piston approaches top center, intense air-flow passes through or near the spark gaps to move and spread the spark towards the cup-like region under the hotter exhaust valve, and further comprising means for improving the lean burn capability of the engine under light load conditions and the knock rating under high loads wherein at least two spark plugs have flexibility relative to each other in terms of ignition firing and timing.

A variable air-fuel ratio (AFR), lean burn internal combustion (IC) engine system for igniting, combusting, and expanding a burnt air-fuel mixture and producing work comprising:

a movable piston within a cylinder that has a cylinder head with single intake and single exhaust valve openings with the combustion chamber located mainly in the head, and wherein the exhaust valve stem is vertical and the exhaust valve is horizontal and has an approximately 65% of the combustion chamber in a cup-like volume essentially under the exhaust valve comprising part of the roof of the combustion chamber, and the intake valve stem is vertical and the intake valve is horizontal and has an approximately 35% of the combustion chamber in a cup-like volume essentially under the intake valve, and further including two major squish lands for producing high squish-flow and turbulence as the piston nears TC on the engine compression stroke, the system constructed and arranged to have two spark plugs placed in a vertical position and oriented such that as the piston approaches top center, intense air-flow passes through or near the spark gaps to move and spread the spark towards the cup-like region under the hotter exhaust valve, and further comprising means for improving the lean burn capability of the engine under light load conditions and the knock rating under high loads wherein at least two spark plugs have flexibility relative to each other in terms of ignition firing and timing,
wherein the air-flow in the engine cylinder is channeled and guided between the two large squish-lands which define a relatively more compact combustion chamber, and the cross-section of the channel “W” is approximately constant confined by the squish lands, so as the piston approaches TC and ignition, it provides an intense, approximately orthogonal-to-the-main-flow with colliding-turbulent-flows to promote good mixing and complete burning of fuel without significantly impeding the main or primary flow-rate.

Dependencies are inferred from the claim text.

2-valve, 2-plug, 2-intake lean burn engine with squish flow with about 2/3 the combustion chamber under the exhaust valve

Life of this patent

2-valve, 2-plug, 2-intake lean burn engine with squish flow with about 2/3 the combustion chamber under the exhaust valve

Life of this patent

Abstract

Claims5