Rotary exhaust control valve for two-stroke cycle engines and process for using the same
AssigneePerformance Industries, Inc.
InventorEyvind Boyesen
Life of this patent
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Abstract
A rotary exhaust control valve for two-stroke cycle engines is disclosed. This valve is oriented at least partially within the exhaust passage and, for each revolution of the engine, delays flow from the combustion chamber through the exhaust passage during the expansion stroke of the piston while permitting full opening of the exhaust passage and blow down to initiate the scavenging cycle of the engine. The valve of the present invention permits complete opening and closing of the exhaust passage during the appropriate portions of the engine cycle. Also disclosed is a mechanical linkage mechanism between the rotary valve and the crankshaft to provide precise control of the exhaust valve throughout the engine cycle.
Claims20
In a two-stroke cycle internal combustion engine having an air intake passage, an exhaust port leading to an exhaust passage, a piston reciprocating in continuous cycles between top and bottom dead center positions in a cylinder, said piston being interconnected with a rotatable crankshaft, at least one transfer passage providing compressed air to a combustion chamber above the piston, and valve means within the exhaust passage adapted to control flow through the exhaust passage, the improvement in said valve means comprising
- a rotary valve member oriented at least partially within said exhaust passage;
- actuating means for said valve member to rotate said valve member continuously between an open position and a closed position;
- and
- said actuating means being in timed relation with said crankshaft rotation and piston movement to move said valve member from said closed position toward said open position after the upper edge of said piston passes downward below the upper edge of the exhaust port, and to move said valve member from said open position toward said closed position when said piston is near its bottom dead center position.
In a two-stroke cycle internal combustion engine including a cylinder, a combustion chamber in the cylinder, an exhaust port spaced from and below the upper end of the combustion chamber leading to an exhaust passage, and a piston carried within said combustion chamber for reciprocation between top and bottom dead center positions, said piston being interconnected with a rotatable crankshaft and functioning as a valve member to open and close said exhaust port, and valve means within the exhaust passage adapted to control flow through the exhaust passage, the improvement comprising
- said valve means comprising a rotary valve element at least partially within said exhaust passage;
- actuating means for said valve element to rotate said valve element continuously between an open position, providing free fluid flow through said exhaust passage, and a closed position, restricting fluid flow through said exhaust passage;
- and
- said actuating means being in timed relation with said crankshaft rotation and piston movement to move said valve element from a closed position toward an open position as the piston passes downward, and to move said valve element from the open position toward the closed position when said piston is near its bottom dead center position.
Dependencies are inferred from the claim text.