Abstract: A variable expansion-ratio engine includes an expansion-ratio adjuster configured to adjust an expansion ratio; a load detector configured to detect an engine load; and a controller configured to control the expansion-ratio adjuster. The controller controls the expansion ratio such that the expansion ratio at the time when the load is below a predetermined load value is set lower than that at the time when the load is equal to the predetermined load value.

Abstract: A variable expansion-ratio engine includes an expansion-ratio adjuster configured to adjust an expansion ratio; a load detector configured to detect an engine load; and a controller configured to control the expansion-ratio adjuster. The controller controls the expansion ratio such that the expansion ratio at the time when the load is below a predetermined load value is set lower than that at the time when the load is equal to the predetermined load value.

Abstract: An in-cylinder direct fuel injection engine is disclosed. The engine comprises a fuel injection valve engaged in a fuel injection hole, a cylinder head, and an ignition plug engaged in an ignition hole, The fuel injection valve is attached to the fuel rail and the fuel injection nozzle injects fuel from the fuel rail. The fuel injection hole and the ignition hole are positioned in a central portion of the a roof of the cylinder head so as to be located between an intake and exhaust air ports and are generally aligned along an axis of a crank shaft.

Abstract: In a direct injection internal combustion engine, a fuel injection valve and a spark plug of adjacent cylinders are inclined at different angles from each other in directions perpendicular to a cylinder arrangement direction in which the cylinders are arranged. Besides, the fuel injection valve and the spark plug of at least one of the cylinders are inclined at different angles from each other in directions parallel to the cylinder arrangement direction. A cooling channel is provided between the fuel injection valve and the spark plug of the at least one of the cylinders.

Abstract: In an exhaust path, a HC trapping material which traps HC contained in exhaust gas temporarily, a H2O trap which traps H2O contained in exhaust gas and a CO oxidation catalyst are arranged in this order from the upstream side, wherein the H2O trap is disposed just upstream of and close to the CO oxidation catalyst. H2O and HC which are components disturbing the activity of the CO oxidation catalyst can be removed efficiently and the adsorption heat and condensation heat of H2O can be efficiently utilized to raise the temperature of the CO oxidation catalyst so that early activation of the CO oxidation catalyst is accomplished just after an engine starts.

Abstract: A direct fuel injection internal combustion engine includes a fuel injector arranged above a center portion of the piston and positioned higher than a combustion chamber upper surface of a cylinder head. The cylinder head includes a recess portion in which a tip of the fuel injector is disposed in a cross sectional view of the cylinder head in a plane perpendicular to a fuel injection center axis. The recess portion is provided with a channel extending longitudinally away from the tip of the fuel injector configured and arranged to reduce negative pressure within the recess portion. The channel is oriented in such a direction as to avoid the interference between the channel and other parts of the cylinder head. When the fuel injector is a multi-hole fuel injector, the channel can be oriented toward a direction along a centerline between two adjacent injection vents of the fuel injector.

Abstract: A direct fuel injection engine is provided that an appropriate stratified fuel-air mixture is formed to conduct good stratified combustion over a wide range of loads. The engine has a fuel injection valve that is arranged at an upper surface of the combustion chamber on or near the center reciprocation axis of the piston and oriented such that the injection center axis of the fuel stream injected therefrom is slanted with respect to the center reciprocation axis of the piston. The piston is disposed in the combustion chamber to move along a cylinder center axis. The piston has a top surface having a first outer cavity having a first cavity center axis, and a second inner cavity located in the outer cavity. The second inner cavity has a second cavity center axis offset from the cylinder center axis of the piston in a direction perpendicular to the cylinder center axis.

Abstract: In a direct injection internal combustion engine, a fuel injection valve and a spark plug of adjacent cylinders are inclined at different angles from each other in directions perpendicular to a cylinder arrangement direction in which the cylinders are arranged. Besides, the fuel injection valve and the spark plug of at least one of the cylinders are inclined at different angles from each other in directions parallel to the cylinder arrangement direction. A cooling channel is provided between the fuel injection valve and the spark plug of the at least one of the cylinders.

Abstract: A fuel injection control device for a direct fuel injection engine is configured to selectively control a fuel injection valve, which is configured and arranged to directly inject a first fuel stream per cycle into a combustion chamber, to use a first fuel injection timing when the controller determines that a stratified air-fuel mixture will be difficult to form during a second fuel injection timing based on a determination of an engine operation parameter by at least one sensor. The first fuel injection timing is set to control the injection valve to inject the first fuel stream during an intake stroke while a piston in the combustion chamber is approximately at an intake top dead center position such that a majority of the first fuel stream injected from the fuel injection valve is received inside a cavity formed on the piston.

Abstract: A direct fuel injection internal combustion engine includes a fuel injector arranged above a center portion of the piston and positioned higher than a combustion chamber upper surface of a cylinder head. The cylinder head includes a recess portion in which a tip of the fuel injector is disposed in a cross sectional view of the cylinder head in a plane perpendicular to a fuel injection center axis. The recess portion is provided with a channel extending longitudinally away from the tip of the fuel injector configured and arranged to reduce negative pressure within the recess portion. The channel is oriented in such a direction as to avoid the interference between the channel and other parts of the cylinder head. When the fuel injector is a multi-hole fuel injector, the channel can be oriented toward a direction along a centerline between two adjacent injection vents of the fuel injector.

Abstract: A direct fuel injection engine is provided that an appropriate stratified fuel-air mixture is formed to conduct good stratified combustion over a wide range of loads. The engine has a fuel injection valve that is arranged at an upper surface of the combustion chamber on or near the center reciprocation axis of the piston and oriented such that the injection center axis of the fuel stream injected therefrom is slanted with respect to the center reciprocation axis of the piston. The piston is disposed in the combustion chamber to move along a cylinder center axis. The piston has a top surface having a first outer cavity having a first cavity center axis, and a second inner cavity located in the outer cavity. The second inner cavity has a second cavity center axis offset from the cylinder center axis of the piston in a direction perpendicular to the cylinder center axis.

Abstract: A wide angle lens system comprises at least three lens element cemented together as a single lens unit and an object side part of the lens unit has a negative refractive power and a rear part of the lens unit has a positive refractive power.

Abstract: An exhaust gas purification apparatus and method is applied to an internal combustion engine. The internal combustion engine generates an exhaust gas to be introduced to an exhaust system thereof. There is provided a reformer and controller. The reformer introduces a fuel and a part of the exhaust gas and generates a reformed gas including at least hydrogen and the controller is programmed to control a fuel supply amount of the fuel introduced to the reformer and an exhaust gas introduction amount of the exhaust gas introduced to the reformer in accordance with a demanded hydrogen amount of the reformer and operating conditions of the internal combustion engine. The exhaust gas is purified while controlling the fuel supply amount and the exhaust gas introduction amount.

Abstract: An optical system for optical communications is composed of a transparent material having a refractive index distribution formed by changing the molar ratio of metal oxide with valence of 2 or more. The metal oxide with valence of 2 or more includes, for example, Fe2O3. Using such an optical system for optical communications, optical communication components such as an optical fiber collimator and an optical isolator are composed.

Abstract: A direct fuel injection engine basically comprises a combustion chamber, a piston with a cavity, a fuel injection valve, a spark plug and a control unit. The fuel injection valve is configured and arranged to directly inject a fuel stream into the combustion chamber in a substantially constant hollow circular cone shape in a stratified combustion region. The control unit is configured to ignite a first air-fuel mixture formed directly after the fuel stream is injected and prior to a majority of the fuel stream striking the cavity when the direct fuel injection engine is operating in a low-load stratified combustion region, and to ignite a second air-fuel mixture formed after a majority of the fuel stream is guided by the cavity toward an upper portion of the combustion chamber above the cavity when the direct fuel injection engine is operating in a high-load stratified combustion region.

Abstract: A fuel injection control device for a direct fuel injection engine is configured to selectively control a fuel injection valve, which is configured and arranged to directly inject a first fuel stream per cycle into a combustion chamber, to use a first fuel injection timing when the controller determines that a stratified air-fuel mixture will be difficult to form during a second fuel injection timing based on a determination of an engine operation parameter by at least one sensor. The first fuel injection timing is set to control the injection valve to inject the first fuel stream during an intake stroke while a piston in the combustion chamber is approximately at an intake top dead center position such that a majority of the first fuel stream injected from the fuel injection valve is received inside a cavity formed on the piston.

Abstract: A direct fuel injection engine basically comprises a combustion chamber, a piston with a cavity, a fuel injection valve, a spark plug and a control unit. The fuel injection valve is configured and arranged to directly inject a fuel stream into the combustion chamber in a substantially constant hollow circular cone shape in a stratified combustion region. The control unit is configured to ignite a first air-fuel mixture formed directly after the fuel stream is injected and prior to a majority of the fuel stream striking the cavity when the direct fuel injection engine is operating in a low-load stratified combustion region, and to ignite a second air-fuel mixture formed after a majority of the fuel stream is guided by the cavity toward an upper portion of the combustion chamber above the cavity when the direct fuel injection engine is operating in a high-load stratified combustion region.

Abstract: An optical system for optical communications is composed of a transparent material having a refractive index distribution formed by changing the molar ratio of metal oxide with valence of 2 or more. The metal oxide with valence of 2 or more includes, for example, Fe2O3. Using such an optical system for optical communications, optical communication components such as an optical fiber collimator and an optical isolator are composed.

Abstract: A wide angle lens system comprises at least three lens element cemented together as a single lens unit and an object side part of the lens unit has a negative refractive power and a rear part of the lens unit has a positive refractive power.

Abstract: An image taking optical unit comprises an image taking optical system including a lens, an image pick-up element mounting substrate on which an image pick-up element chip is mounted, and a frame member for retaining the both. The frame member comprises a lens positioning face and a substrate positioning face, both of which cooperate to align centers of the lens and chip and position them with a suitable distance. The lens positioning face comprises a vertically lens positioning section for determining a vertical lens position and a horizontally lens positioning section for determining a horizontal lens position. The substrate positioning face comprises a vertically substrate positioning section for determining a vertical substrate position and a horizontally substrate positioning section for determining a horizontal substrate position.