Southwest Research Institute

Sanshin Kogyo Kabushiki Kaisha

Bendix Commercial Vehicle Systems LLC

Osaka Gas Company Limited

Susumu Ariga

Valery Dunaevsky

Yukiyoshi Fukano

Jongmin Lee

A piston for use in internal combustion engines or reciprocating compressors such as those utilized in air-brake systems for heavy duty freight vehicles. The body of the piston of the present invention is contoured in manner to reduce the undesirable build-up of oil pressure that frequently occurs at the oil control ring or rings when the piston is in operation. The crown portion of the piston body includes a series of piston ring groove and piston ring lands, one of which is modified to include drainage notches. The skirt portion of the piston body includes a plurality of furrows near the face of the piston, a horizontal channel recessed into the surface of the piston skirt, and a horizontal groove formed in the outer skirt wall of the piston. These structures function individually and in combination to provide multiple means by which excess lubricating oil may be directed away from the oil control rings and back toward the crankcase or oil reservoir within the engine or compressor.

Contoured piston

A heat exchanger is provided in an oil recirculation system that is exclusively dedicated to providing lubrication of the valve train in an overhead cam engine. The flow rate of oil through the heat exchanger is controlled to maintain the temperature of oil disposed in a reservoir formed in an enclosure in which the overhead cam and associated valve train components are mounted, at a value sufficient to assure a sufficiently thick oil film between sliding components of the overhead cam valve train under high surface contact loads.

Independent valve train lubrication system

Noncontacting surface areas are provided between the top wall of an oil control ring and the top surface of its groove to avoid entrapment of oil between adjacent surfaces of the two members during downward motion of a piston in a reciprocating, internal combustion engine. The noncontacting surface areas may be provided by circular grooves formed in the top surface of the groove or the ring. Alternatively, either the top surface of the groove or the top wall of the oil control ring may be formed so that it slopes away from the surface of its mating member and forms a tapered annular cavity that diverges away from the outer cylindrical surface of the piston. All of the described arrangements reduce the contact area between the top of the ring and the top of the groove during downward movement of the piston, thereby permitting the oil control ring to seal against the upper surface of its groove. The present invention effectively controls the flow of oil toward the compression ring during intake and expansion strokes of the engine.

Oil control ring and groove arrangement for improved blowby control

A plurality of passageways were provided between the inter-ring cylindrical surface of a piston and a cavity formed behind an oil control ring mounted on the piston. The passageway provides for the passage of blowby gas during downward movement of the piston, thereby permitting the oil control ring to seat against the upper surface of its groove. The present invention effectively controls the flow of oil toward the compression ring of the ring assembly without the requirement for a passageway communicating the inter-ring cavity with a saturated, turbulent flow, oil environment.

Blowby pressure control above an oil control ring in a reciprocating

A valve system for use in internal combustion engines includes a means for controllably varying the preload force imposed on a valve spring in correlation with engine speed. At low engine speeds the preload force is maintained at a minimal level whereby the normal load at the cam/follower interface is maintained at a minimal value. At higher engine speeds, the preload force on the valve spring is selectively increased to assure positive closure of the valve head. The increased preload forces are imposed by extending a hydraulically actuated, moveable spring seating surface whereby the installed length of the spring is shortened. The hydraulic actuating fluid is continuously circulated through inlet and outlet ports, communicating with an expandable chamber associated with the moveable seating surface, during low engine speed operation to abate the problem of temperature rise in static fluid systems.

Variable preload system for valve springs

A toroidal chamber in a piston communicating through an orifice at a top face of the piston located in an internal combustion system, such as a spark ignition engine or a compression ignition engine. The chamber arranged to receive a fuel/air mixture so that a flame front, propagated in a main combustion chamber outside the toroidal chamber reaches the toroidal chamber, the fuel in the toroidal chamber burns. The burning creates pressure in the chamber that exceeds the pressure in the main combustion chamber. The combustion gas of high pressure is jetted out of the toroidal chamber into the main combustion chamber. The high pressure combustion gas jet generates turbulence and mixing in the main combustion chamber, contributing to an improved combustion. Accordingly, the power output and the thermal efficiency of the internal combustion system is improved.

Lean-burn internal combustion system

Apparatus and method for operating a 2-stroke or 4-stroke reciprocating compression-ignition internal combustion engine, of the direct injection type, to reduce fuel consumption and to reduce NO.sub.x emissions. A staged fuel injection process involving two fuel injectors, but only one type of fuel, is used. A low pressure fuel injection device injects a pilot fuel charge into the combustion chamber when the combustion chamber is near its lowest pressure and its maximum volume. The pilot fuel charge stratifies within the combustion chamber, and undergoes a preflame reaction with a resultant release of heat energy. Near the end of the compression stroke of the piston, when the combustion chamber is near its minimum volume, a high pressure fuel injector injects a main fuel charge into the combustion chamber. The main fuel charge is ignited by the burning pilot fuel charge, and combustion of the main fuel charge is accelerated by the heat energy released by the pilot fuel charge preflame reaction. This accelerated combustion process reduces the ignition delay and premix combustion rate, and results in reduced fuel consumption and NO.sub.x emissions, without adversely affecting either combustion noise levels or particulate emission.

Staged direct injection diesel engine

An internal combustion engine including a head (29), a cylinder block (20) containing a cylindrical bore (22) and a piston (27). The piston (27) is located within the cylinder bore (22) of the cylinder block (20) for reciprocating motion in the longitudinal direction of the cylinder bore (22). The piston (27) includes at least one annular groove (32) around its circumference in which is fitted a compression piston ring (40). The piston ring (40) forms a gas seal between the piston (27) and wall of the cylinder bore (22). The lateral surface (34) of the piston ring groove nearest the combustion chamber (24) which is formed by the piston (27) and cylinder bore (22), has formed in it a plurality of radially directed channels (38), each channel forming a gap (46) for introducing gas pressure from the combustion chamber (24) through the clearance space (42) between the piston (27) and cylinder bore ( 22) and into the piston ring groove (32). The combustion gas pressure thus introduced produces a force against the piston ring (40) which keeps it sealed against the surface of the piston ring groove (35) opposite the combustion chamber (24).

Compression piston ring groove for an internal combustion engine

A combustion chamber for a spark assisted diesel engine embodying a main combustion chamber and an energy cell. Fuel is injected into the main chamber and into the energy cell and combustion is initiated in the main chamber. The energy cell communicates with the main chamber through a restricted orifice and the increased pressure of the combustion causes auto ignition in the energy cell to generate a high velocity charge out of the energy cell into the main chamber through the orifice for generating turbulence to insure complete combustion.

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San Antonio, TX, United States of America

Susumu Ariga