Abstract: An engine valve includes a stem, a head comprising an outer lip surface, a seating surface extending from the outer lip surface toward the stem, and a combustion surface extending from the outer lip surface on the opposite side of the head as compared to the seating surface. The combustion surface includes a first convex arcuate surface spaced away from the outer lip surface, at least partially forming a raised ring, and a first concave arcuate surface spaced away from the outer lip surface, at least partially forming a dimple.

Abstract: A valve system that includes a housing defining an intake port, a cylinder port and a valve bore; wherein the intake port defining a valve seat portion at an interface between the intake port and the cylinder port. The valve system also includes a valve to control fluid communication between the intake port and the cylinder port. The valve includes a valve stem disposed within the valve bore and extending into the cylinder port and extending out of the housing, the valve stem having an open face exposed to atmospheric pressure and a valve head coupled to the valve stem comprising a first face and an opposing second face. A diameter of the valve stem is selected to control a closing force on the first face of the valve head.

Abstract: An engine includes a combustion chamber, a cylinder head, an intake valve, a partition wall plate, and a tumble valve. The cylinder head includes an intake port that communicates with the combustion chamber. The intake valve includes a head configured to open and close an open end of the intake port. The partition wall plate partitions the intake port into first and second passages. The tumble valve is configured to open and close either one of the first passage and the second passage. A cross sectional shape of the partition wall plate is defined on a basis of a shape of a gap that is surrounded by a contour of the head and a contour of the open end, as viewed in a reference direction. The reference direction is a direction from a reference point in the intake port to a gap between the open end and the head.

Abstract: An internally cooled inlet or outlet valve for internal combustion engines, has a valve disc, a valve stem and a cavity inside the valve stem and the valve disc. A coolant is arranged in the cavity, wherein the cavity is provided with at least one guide vane for the coolant.

Abstract: A method for manufacturing a poppet valve 10 from an intermediate valve products is disclosed. The intermediate valve products have an intermediate valve head 14? with a pressing protrusions 15. A peak 15a of the pressing protrusions 15 is located in a normal direction X2 of the seat surface N, which is positioned on a normal line X2 passing a reference point P3 set on a line segment K connecting a base point P1 in an inner side and a base point P2 in an outer side of the seat surface N; a position of the reference point P3 is set such that a relation between a length L1 from the base point P1 to the reference point P3 and a length L2 from the base point P2 to the reference point P3 meets a formula of L1/L2?0.5.

Abstract: A coolant control valve includes a cam rotating by rotational force; a pivot arm disposed under the cam, one end of the pivot arm moving in an up and down direction by rotation of the cam; a valve installed at another end of the pivot arm and disposed outside an outer diameter of the cam, the valve moving as the pivot arm moves; and a pivot arm support hinge for supporting the pivot arm and enabling vertical movement of the pivot arm when the cam rotates.

Abstract: In an assembly of a hollow poppet valve and a valve seat insert, the hollow poppet valve's head is integrally formed with a stem end, a hollow part is formed from the head to a stem, and coolant is filled into the hollow part along with an inert gas. The valve seat insert is formed of iron base sintered alloy and obtained by integrating two layers of a supporting material side layer and a valve contact face side layer. The hollow poppet valve is formed of a material having thermal conductivity of 5-45 (W/m·K) at 20-1000° C. The valve seat insert includes the supporting material side layer having thermal conductivity of 23-50 (W/m·K) at 20-300° C. and a valve contact face side layer having thermal conductivity of 10-22 (W/m·K) at 20-300° C. This enables a valve temperature decrease throughout an engine's entire RPM range compared with the prior art.

Abstract: Example systems and methods for nondestructive ultrasonic testing are provided. One example system includes at least one air-coupled ultrasonic transducer configured to emit primary ultrasound waves that interfere with each other. The primary ultrasound waves include fundamental frequency components that are multiples of each other and emitted simultaneously in locked phase. Further, the interference of the primary ultrasound waves generates a plurality of frequency harmonics in the air. The system also includes at least one receiver configured to receive ultrasonic waves emitted from an object under test.

Abstract: An intake valve for an internal combustion engine is provided. The intake valve includes a valve stem with a hole in the valve stem forming an air channel there through that allows intake air to flow from an intake passage, through the air channel, into a cylinder of the internal combustion engine.

Abstract: An internal combustion engine with a piston having a piston head with a resonance cavity opening onto the head, and where a fuel nozzle located in a cylinder head is positioned to inject a fuel such as natural gas into the combustion chamber where resonance formed within the resonance cavity will ignite the fuel without the need of a spark plug. Inlet and exhaust ports in the cylinder head allow for air and combustion gas enter or leave the combustion chamber.

Abstract: An object of the invention is to provide an internal combustion engine that suppresses a blow-by phenomenon in an overlap period, while allowing for formation of a favorable swirl flow in a combustion chamber. In the internal combustion engine, a housing space is formed in an opening of an exhaust port to the combustion chamber to be more recessed in a cylinder head than an exhaust port-side ceiling surface. A bevel portion of an exhaust valve is placed in the housing space in a valve closed state of the exhaust valve. A valve contact surface is formed on an inner wall surface of the housing space.

Abstract: Exemplary embodiments are directed to vent valves, systems and methods generally involving a valve body that includes a seat retainer, a needle and a seat. The seat includes a bore extending there through and the needle includes a needle stem and a needle head. The seat is disposed inside the seat retainer. The needle stem is disposed inside the bore. The needle is configured to be pulled through the seat to stop flow through the bore. Exemplary embodiments are further directed to a system including a stem return spring mechanism and a solenoid return spring mechanism. A processing device is configured to actuate the solenoid return spring mechanism to permit the stem return spring mechanism to pull the needle through the seat to stop flow through the bore.

Abstract: A positive displacement pump fluid end with multiple fluid chambers and each fluid chamber comprising a valve body, valve seal, seat, spring, and external guide. External top male stem guide is integral to the fluid end discharge cover or the suction valve spring retainer. Female guide is internal and integral with the valve body. When the valve opens hydrodynamic forces and moments align the valve to prevent rotation. An embodiment features tapered male and female guide members to further assist in correct alignment of the valve with the seat. Various additional embodiments assist in venting any trapped fluids between the male and female portions of the guide.

Abstract: An inventive automated heat treatment system has a furnace for heat treating forged engine valves, a carry-in mechanism for transporting the forged valves into the furnace, and a carry-out mechanism for transporting heat treated valves out of the furnace. Each of the carry-in mechanism and the carry-out mechanism has a retention mechanism for retaining valves hung, and a transport mechanism for transporting valves to the furnace as they are hung. The furnace has heating means, groups of paired rails for supporting and moving the valves hung in the furnace, and a stopper for controlling the positions of the valves on the rails. The engine valves are maintained hung with their umbrella-shaped portions supported by the respective mechanisms throughout the automated heat treatment processes. Thus, the heat treatment of engine valves is done in a fewer steps than in a conventional system.

Abstract: Disclosed is an engine that comprises an engine block, and the engine block comprises a cylinder. The engine further comprises a cylinder head mounted to the engine block, and the cylinder head comprises an intake valve seat and a shroud. Further yet, the engine comprises a combustion chamber formed at least partially by the cylinder and the cylinder head. The intake valve is configured to travel between a fully closed position seated against the intake valve seat and an opened position displaced from the intake valve seat, thus allowing intake flow through the intake valve seat into the combustion chamber. The shroud only partially surrounds a periphery of the valve and extends along at least a portion of the travel of the intake valve so as to restrict intake flow along only a portion of the intake valve.

Abstract: A valve for an engine cylinder includes a head. The valve is selectively moveable between a closed position in which the head blocks a port and an open position in which the head unblocks the port. A lower stem is formed as one-piece with the head, and a thermal cavity formed within the lower stem. The thermal cavity is at least partially filled with a heat transfer medium. An upper stem is attached to the lower stem opposite the head. A thermal barrier is located adjacent a junction of the lower stem and the upper stem.

Abstract: A heat transferring engine valve for an internal combustion engine to increase the combustion efficiency and fuel economy of the engine. The heat transferring valve includes a valve head and a heat transferring member situated at the combustion surface of the valve head and extending toward the combustion chamber. The heat transferring member absorbs heat of combustion during the power stroke of an engine cycle and releases the heat into the combustion chamber during the compression stroke of a succeeding engine cycle, thereby raising the temperature of fuel at the start of combustion. A method for increasing the efficiency of combustion in an internal combustion engine by incorporating at least one heat transferring valve into the engine.

Abstract: A method for producing a hollow engine valve is disclosed which involves gradually reducing the size of the outer diameter and inner diameter of a hollow shaft of a semi-finished product sequentially inserting the hollow shaft into a plurality of molding holes having different hole shapes so as to gradually extend the length of the hollow shaft, and forming the hollow shaft into a predetermined shape by sequentially performing a drawing process. The semi-finished product is subjected to heat treatment such that the hardness thereof is equal to or less than a predetermined hardness, and the maximum thickness between the hollow shaft and an umbrella portion connected to the bottom edge of the hollow shaft is formed to be thicker than the thickness of the hollow shaft by means of a molding hole of a die which is adjusted to have a specific length and maximum inner diameter.

Abstract: For reducing the NOx-emission of a large sized two stroke diesel engine having at least one combustion room (3), a reciprocating piston (4) and an exhaust opening (12) controlled by an exhaust valve (13) at each work cyclus a small volume of burnt gas is retained in the combustion room (3) and so added to the fresh air for the next combustion. For achieving this retention of burnt gas the underside of the valve disc (15) off the exhaust valve (13) is provided with a shallow concave face (17) building a basin-like collection room, whose depth is within a range of 2-10% of the outer diameter of the valve disc (15).

Abstract: A valve stem seal for an internal combustion engine includes a seal body having a gas seal assembly spaced from an oil seal assembly in the axial direction of the valve stem seal. The gas seal assembly includes a first gas lip and a second gas lip disposed between the oil seal assembly and the first gas lip.

Abstract: Disclosed is a method—for producing an engine valve (V) filled with metallic sodium (Na) within by means of: forming a stem section (S), which has a hollow section (H), at an intended size by successively drawing the stem section (S) using dies (D1, D2, Dx, Dx+1, Dn) in a manner so as to causing the size of the outer diameter and the inner diameter of the stem section (S) to contact in a stepwise fashion; and inserting metallic sodium (Na) into the hollow section (H) of the stem section (S)—wherein after drawing the stem section (S) until the inner diameter of the hollow section (H) of the stem section (S) has become a prescribed size (steps S11-S15) and then inserting the block-shaped solid metallic sodium (Na) into the hollow section (H) of the stem section (S) (step S16), the stem section (S) is further drawn (steps S17 and S18).

Abstract: A poppet valve for controlling fuel in an electronically actuated valve assembly for diesel engine fuel injection systems comprising along a common axis a stem with a cylindrical guide and a neck, and a circular head, the neck being smaller in cross section than the guide, and the head being larger than the guide, the head having a conical surface facing the guide, the conical surface having an annular primary sealing area and a receding surface area radially outward of the primary sealing area, the primary sealing area having an inside diameter less than a diameter of the guide, an outside diameter greater than the guide and oriented obtusely to the axis, the receding surface area merging with the primary sealing area at an outside diameter of the primary sealing area, the receding surface area being oriented more obtusely to the axis than the orientation of the primary sealing area.

Abstract: A forged exhaust poppet valve and a method of solution heat treating the same are provided. The forged exhaust poppet valve (10) includes a head portion (12) which has a seat portion (14) on the outer periphery thereof and is integral with a diametrically tapered neck portion (16) connected to a stem portion (18). Using a radio-frequency heating apparatus, a solution heat treatment is given to a predetermined transitional region (A) of the neck portion and the stem portion that is exposed to exhaust air during a valve opening period such that the grain size in the region (A) does not exceed ASTM 10, thereby securing a necessary high-temperature creep strength in the region (A) and a necessary hardness (wear resistance) in the seat portion (14) and thereby rendering the exhaust poppet valve highly durable.

Abstract: An engine assembly includes a uni-cast, piston-enclosing chamber structure and a solenoid valve pack. The chamber structure includes a piston-receiving chamber, a gas intake port, an intake valve port, a gas exhaust port, and an exhaust valve port. The gas intake port communicates with the intake valve port, and the gas exhaust port communicates with the exhaust valve port. The solenoid pack includes gas intake and gas exhaust solenoid valve assemblies. The solenoid pack is attachable to the chamber structure such that the gas intake valve port axially aligns with a gas intake valve-receiving column, and the gas exhaust valve port axial aligns with a gas exhaust valve-receiving column. The intake valve is bi-directionally displaceable as received in the gas intake valve port and the gas intake valve-receiving column. Similarly, the exhaust valve is bi-directionally displaceable as received in the gas exhaust valve port and gas exhaust valve-receiving column.

Abstract: Provided is a method for producing an engine valve by subjecting a stem portion having a hollow part to a drawing treatment using a series of dies such that the outer diameter and inner diameter of the stem portion become smaller in steps and the stem portion is thereby molded to the desired size, whereby, after the stem portion has been subjected to the drawing treatment until the inner diameter of the hollow part of the stem portion has reached a specific size, sodium metal in the form of a solid block is introduced to the hollow part of the stem portion, and a protective agent made from solid paraffin or naphthalene is also introduced to the hollow part of the stem portion such as to form a barrier between the sodium metal and the atmosphere, after which the stem portion is further subjected to a cold drawing treatment.

Abstract: A split-cycle engine includes a crankshaft rotatable about a crankshaft axis. A compression piston is slidably received within a compression cylinder and operatively connected to the crankshaft such that the compression piston reciprocates through intake and compression strokes during a single rotation of the crankshaft. An expansion piston is slidably received within an expansion cylinder and operatively connected to the crankshaft such that the expansion piston reciprocates through expansion and exhaust strokes during a single rotation of the crankshaft. A crossover passage interconnects the expansion and compression cylinders. The crossover passage includes crossover compression (XovrC) and crossover expansion (XovrE) valves defining a pressure chamber therebetween. At least one of the XovrC and XovrE valves is a balanced valve.

Abstract: An assembly can include a valve seat for an exhaust bypass valve of a serial turbocharger system where the valve seat includes a base portion and a wall portion that extends axially away from the base portion; and a gasket that includes a planar portion that defines a perimeter and a socket disposed interior to the perimeter, where the socket includes a valve seat surface axially recessed from the planar portion and configured to position the seat. In various examples, the valve seat is positioned in the socket of the gasket and fixed to the gasket. Various other examples of devices, assemblies, systems, methods, etc., are also disclosed.

Abstract: An intake apparatus of an engine includes: a first intake passage supplying fresh air to a cylinder; a second intake passage arranged near the first intake passage, and supplying fresh air to the cylinder; a first intake valve opening and closing the first intake passage at an aperture of the first intake passage; a second intake valve opening and closing the second intake passage at an aperture of the second intake passage. An opening timing of the first intake valve of the intake apparatus advances relative to a top dead center, and a valve lift amount of the first intake valve differs from that of the second intake valve, and there is a period while the valve lift amount of the first intake valve is larger than that of the second intake valve, in an intake stroke.

Abstract: An inlet valve includes a valve head including a valve surface located at a circumferential edge portion, and a single annular circumferential edge groove disposed radially inside and close to the valve surface in the circumferential edge portion. When intake air (an airflow) proceeds along a surface of the valve head and reaches the circumferential edge portion, only a portion thereof (a partial airflow) enters the circumferential edge groove and the remaining thereof (remaining partial airflow) passes by the circumferential edge groove. As the intake air (the partial airflow) having entered the circumferential edge groove forms a turbulent flow, the intake air surrounds the circumferential edge portion of the valve head and reaches below the circumferential edge portion of the valve head, thereby achieving an increase in volume of air taken into a combustion chamber.

Abstract: An automotive engine valve stem, engine valve and method of producing both. The valve includes a head and a stem joined to the head. Lightweight, high-temperature materials, such as titanium-based materials may be used to make up at least a the majority of the valve. These materials are combined with fabrication techniques that may vary between the head and the stem, where at least a part of the valve is made by dynamic magnetic compaction. While a majority of the stem may be made from a titanium-based powder material, its tip may be made of a high strength hardened material, such as a steel alloy. The valve head may be made by single press and sintering, double press and sintering, forging and machining, forging and sintering, and dynamic magnetic compaction and sintering.

Abstract: An exhaust valve includes: a shaft section; and a head section that is formed in one end of the shaft section and formed with a valve face that seats on a valve seat disposed in a cylinder head of an internal combustion engine, in which the shaft section has a shaft diameter of a constant diameter; the head section has a head diameter that is larger than the shaft diameter; and a thick shaft section that has a diameter smaller than the head diameter and larger than the shaft diameter is formed within a section between a connecting position that connects the shaft section with the head section and a position that is spaced apart from the head front surface opposite to the valve face in an axial direction by a distance that is approximately the same as the head diameter.

Abstract: To improve the precision of the control of the charge of a cylinder during idling and low revs/light load operation, a bypass feeding path of low flow capacity provides the cylinder with air or mixture while the high flow capacity intake valves stay closed.

Abstract: An engine assembly may include an engine block defining a cylinder bore, a cylinder head fixed to the engine block, and a valve seat insert. The cylinder head may include an intake port, defining an inlet in fluid communication with an air source and an outlet in fluid communication with the cylinder bore. The valve seat may be defined at the outlet of the intake port and may include a stepped region. The stepped region may define a seating surface extending radially outward from the intake port. The seating surface may include a series of protrusions circumferentially spaced from one another around the outlet and forming a series of recesses therebetween. The valve seat insert may be located within the stepped region and may include a first axial end surface abutting the protrusions on the seating surface.

Abstract: A valve apparatus for an internal combustion engine, the valve apparatus including: a main part having a wall section defining a valve cavity extending along a longitudinal length of the main part and an opening located in the wall section of the main part, the opening flow connected to the combustion chamber; an outer part configured and arranged so as to be reciprocally located in the valve cavity, the outer part having a wall section defining an inner passage extending along a longitudinal axis thereof; an inner part having a first end situated outside of the cavity and a second end situated within the cavity and the inner passage of the outer part, the inner part having a wall section defining an inner passage, a first opening at the first end, and one or more openings in that part of the walled section which is situated within the cavity.

Abstract: A multicylinder engine for a motorcycle includes a valve actuation mechanism having a hydraulically-operated valve pausing mechanism for holding at least one of an intake valve and an exhaust valve of selected cylinders in a suspended state. The valve actuation mechanism operates the intake valve and the exhaust valve, and controls flow of oil through an oil passage which introduces working oil to the valve pausing mechanism from a hydraulic-pressure control device. Air-bleeding holes are formed in the cylinder head. The air-bleeding holes are fluidly connected with portions of the oil passages that are located at a highest level in the oil passages while the motorcycle is parked in an inclined state with its side stand down.

Abstract: A hollow poppet valve has a stem portion provided at one end thereof with a tip portion; a cap portion; and a flared fillet portion formed between the stem portion and the cap portion, wherein at least a part of the stem portion that connects to the fillet portion is a thin hollow cylindrical member, and the cap member is welded to the fillet portion. The cap member is thin and has an arcuate axial cross section. It is laser-beam welded to the seat-abutment portion formed at the open end of the fillet portion such that a weld bead is formed along the inner periphery of the interface of the mated ends of the members. The weld bead adds an extra weld depth to the weld, which increases the modulus of section of the welded regions of the cap member and the fillet portion and enhances their welding strength.

Abstract: Forming of a valve head portion (1) of a hollow engine valve (V) comprising a material particularly satisfactory in heat resistance is performed by cold forging. On this occasion, the material with excellent heat resistance is worked to form a valve head portion semifinished product (11) having a hollow hole (S11) whose inner diameter (?11) is equal to the maximum inner diameter (?11) of a hollow hole (S1) of a finished product of the valve head portion (1), and having a diameter-increased section (111) whose maximum outer diameter (?12) is equal to the maximum outer diameter (?12) of a diameter-increased section (1a) of the finished product. Parts of the valve head portion semifinished product other than a central part to a lower part of the diameter-increased section (111) are necked down by cold forging performed a plurality of times to obtain the finished product of the valve head portion (1). This method of obtaining the finished product is provided by the present invention.

Abstract: An electric vehicle and a range extender engine are shown including the controls to operate the same.

Abstract: A method for manufacturing a lightweight valve is provided. The lightweight valve includes a valve stem, a hollow valve cone and a valve disk closing the valve cone, the valve stem being provided with a hollow space at an end facing the valve disk, the valve disk also having a force transmission element extending through the hollow valve cone into the stem hollow space. The method includes producing a first one-piece component forming the valve disk with the force transmission element by casting, forming and/or a powder metallurgy method, producing a second component forming the valve stem and the valve cone and joining the first and second components together and connecting them by a material, non-positive and/or positive connection.

Abstract: An inlet valve includes a valve head including a valve surface located at a circumferential edge portion, and a single annular circumferential edge groove disposed radially inside and close to the valve surface in the circumferential edge portion. When intake air (an airflow) proceeds along a surface of the valve head and reaches the circumferential edge portion, only a portion thereof (a partial airflow) enters the circumferential edge groove and the remaining thereof (remaining partial airflow) passes by the circumferential edge groove. As the intake air (the partial airflow) having entered the circumferential edge groove forms a turbulent flow, the intake air surrounds the circumferential edge portion of the valve head and reaches below the circumferential edge portion of the valve head, thereby achieving an increase in volume of air taken into a combustion chamber.

Abstract: A combustion chamber is provided within an internal combustion engine, the combustion chamber including a cylinder head having an internal bore with an open end and a closed end, and a piston which reciprocates within the internal bore between a TDC position near the closed end and a BDC position, with a compression end facing the closed end. Poppet valves on the closed end and ports on the internal bore can control the flow of gasses into, and from, the combustion chamber. The combustion chamber is stratified when the compression end is positioned within a stratified distance of the closed end. When stratified, the combustion chamber is comprised of a central combustion region, a perimeter squish region, and a transfer passage between the regions. A direct fuel injector injects fuel into the central combustion region, mixing fuel with inducted gasses prior to combustion. The combustion chamber can be thermally insulated.

Abstract: The valve system for opposed piston engines essentially comprises a single poppet valve opening into the common combustion chamber between the two opposed pistons of each piston and cylinder pair. The engine for which the mechanism is adapted includes a rotating internal cylinder surrounding each piston pair, with a stationary outer cylinder or case surrounding the rotating cylinder. The valve is pivotally attached at one side or end thereof to the edge of the valve port of the rotating cylinder, and is actuated by an arm or arms having guides (rollers, etc.) at the distal end(s) thereof, which are captured in corresponding cam track(s) or channel(s) formed in the fixed outer cylinder or case of the engine. The cam track has a variable radius, with the valve arm(s) and guide(s) alternately lifting and lowering as the guide(s) travel(s) in the variable radius cam track(s), thereby closing and opening the valve.

Abstract: An intake/exhaust valve seal structure for an internal combustion engine is disclosed. A sealing surface is formed by a valve seat surface in a ceiling of a combustion chamber and a valve face surface provided on an intake/exhaust valve. The sealing surface lies on a first conical surface having an axis of the intake/exhaust valve as its rotation axis and includes a line of intersection of the first conical surface with an inner wall face of the ceiling of the combustion chamber. A method for manufacturing the intake/exhaust valve is also disclosed.

Abstract: To achieve high compression ratio and lower temperature of the exhaust poppet valve in an engine provided with a poppet valve on an extend part of a combustion chamber outside a main cylinder, disclosed is a valve cover having a cylindrical side face and upper face, an compression ring either the cylindrical side face and an inner wall of the sub cylinder, means to contact closely a bottom face of a poppet valve and the upper face of the valve cover, the upper part of the valve cover occupying most part of the combustion chamber facing with the bottom face, the valve cover moves along with the poppet valve when the poppet valve is lifted, a combination of overhead valves and the poppet valve including one intake valve and one exhaust valve, and total number of the overhead valve and poppet valve is not less than 3.

Abstract: One embodiment of the present invention provides a poppet valve offering an increased valve area, comprising an outer valve head having an outer valve port and an inner valve head having an inner valve port. The inner valve head is rotatable relative to the outer valve head to align the inner and outer valve ports, thereby increasing the effective valve area of the poppet valve. The path created by aligning the inner and outer valve ports can be designed to mix air flowing through the poppet valve. Another embodiment of the present invention provides a valve guide containing a poppet valve having a guide pin, wherein the guide pin rests within a groove in the valve guide. As the poppet valve moves through the valve guide, the groove controls movement of the guide pin and causes the poppet valve to rotate relative to the valve guide.

Abstract: Motor control means of a motor poppet valve has initial motor torque setting means for setting the initial motor torque of an electric motor so that the initial motor torque equals a torque corresponding to a force biasing a valve element of a poppet-valve body toward a valve seat or a proximate value, and drives the electric motor so as to obtain the initial motor torque when driving the electric motor to detach the valve element from the valve seat.

Abstract: Disclosed is an internal combustion engine (A), which has a valve overlap period (T) during which an intake valve (1) and an exhaust valve (2) are opened, and a geometric compression ratio of 13.0 or greater. The engine (A) is designed to satisfy, at a center timing (Tc) of the valve overlap period (T), a conditional expression: S1?S2, where S1 is a cross-sectional area of a combustion chamber (4) taken along any selected one of a plurality of mutually parallel hypothetical cutting-planes (IP) each of which extends parallel to a linear reciprocating direction (d1 or d2) of at least one of the intake and exhaust valves (1, 2) and passes through a valve head (1a or 2a) of the at least one of the valves (1, 2), and S2 is an effective opening area defined between the valve head (1a or 2a) and a corresponding valve seat (11a or 12a) in a region on an outward side of the combustion chamber (4) relative to the selected hypothetical cutting-plane (IP).

Abstract: A variable valve lift apparatus according to an exemplary embodiment of the present invention includes an inner body contacting an input cam, an outer body connected with a valve, a lost motion spring disposed between the inner body and the outer body for supplying restoring force to the inner body, a return pin assembly supplying connecting force to the inner body and the outer body, and an operating portion selectively disconnecting the inner body from the outer body.

Abstract: One embodiment of the present invention provides a poppet valve offering an increased valve area, comprising an outer valve head comprising an outer valve port and an inner valve head comprising an inner valve port. The inner valve head is rotatable relative to the outer valve head to align the inner and outer valve ports to open a path through the poppet valve, thereby increasing the effective valve area of the poppet valve. The path created by aligning the inner and outer valve ports can be designed to mix air flowing into a combustion chamber.

Abstract: An intake valve assembly of an internal combustion engine that includes a combustion chamber and an intake passage. The intake valve assembly comprises a primary valve provided to seal against a primary valve seat formed in an intake port, a secondary valve mounted about the primary valve coaxially therewith and provided to seal against a secondary valve seat formed in the intake port, and a secondary valve lifter fixed to the primary valve so as to be axially spaced from the secondary valve when both the primary and secondary valves are in closed positions. The secondary valve is operated mechanically by the secondary valve lifter and fluidly in response to pressure differential between the intake passage and the combustion chamber.