Abstract: The present invention provides a power generation device that can not only reduce the generation of vibration but also increase thermal efficiency. A power generation device (10A) includes: an engine (1) in which a right crankshaft (31) and a left crankshaft (32) rotate in opposite directions to each other; a right flywheel (41) and left flywheel (42) as a primary inertia body; and a power generation motor (2) as a secondary inertia body, a total inertia moment in a first rotation direction and a total inertia moment in a second rotation direction being balanced with each other by not less than 50%.

Abstract: The present invention provides a power generation device that can not only reduce the generation of vibration but also increase thermal efficiency. A power generation device (10A) includes: an engine (1) in which a right crankshaft (31) and a left crankshaft (32) rotate in opposite directions to each other; a right flywheel (41) and left flywheel (42) as a primary inertia body; and a power generation motor (2) as a secondary inertia body, a total inertia moment in a first rotation direction and a total inertia moment in a second rotation direction being balanced with each other by not less than 50%.

Abstract: A control device controls a valve timing changer to retard a phase of an exhaust valve camshaft with respect to a crankshaft such that the time of opening of an intake valve is earlier than the time of closing the exhaust valve after a top dead center, when a determiner determines that an engine is not in a warm-up stage in a low-load operation. The control device controls the valve timing changer to advance the phase of the exhaust valve camshaft with respect to the crankshaft such that the time of closing the exhaust valve is earlier than the time of opening of the intake valve after the top dead center, when the determiner determines that the engine is at the warm-up stage in the low-load operation.

Abstract: A control device controls a valve timing changer to retard a phase of an exhaust valve camshaft with respect to a crankshaft such that the time of opening of an intake valve is earlier than the time of closing the exhaust valve after a top dead center, when a determiner determines that an engine is not in a warm-up stage in a low-load operation. The control device controls the valve timing changer to advance the phase of the exhaust valve camshaft with respect to the crankshaft such that the time of closing the exhaust valve is earlier than the time of opening of the intake valve after the top dead center, when the determiner determines that the engine is at the warm-up stage in the low-load operation.

Abstract: A four-cycle engine (1) structured to introduce fresh air into a cylinder (1a) via an intake port (1d) opened/closed by intake valves (IN1, IN2) and suck exhaust gas back into the cylinder (1a) via an exhaust port opened/closed by exhaust valves (EX1, EX2), wherein the exhaust port has a first exhaust port (1p) and a second exhaust port (1e), and the exhaust gas is sucked in back from the first exhaust port (1p) and secondary air is sucked in from the second exhaust port (1e) to form, in the cylinder (1a), a first temperature layer (T1) at a high temperature mainly composed of the exhaust gas and a second temperature layer (T2) at a temperature lower than that of the first temperature layer (T1) mainly composed of the secondary air.

Abstract: A four-stroke engine (1) structured to introduce fresh air and EGR gas into a cylinder (1a) includes a blowdown supercharging system (40) using a combustion chamber internal pressure when exhaust valves open in an expansion stroke of a first cylinder (hereinafter denoted as an exhaust blowdown pressure) for introducing EGR gas into a second cylinder from near a bottom dead center of an intake stroke to near a bottom dead center of a compression stroke of the second cylinder which is different from the first cylinder in combustion timing, and a secondary air supply system (20) supplying secondary air to an exhaust port (1e) of the second cylinder prior to arrival of the exhaust blowdown pressure at the second cylinder. The secondary air in the exhaust port and the EGR gas are supercharged into the second cylinder by the exhaust blowdown pressure from the first cylinder.

Abstract: An average pressure P12 in an exhaust port at an overlap period T12 during which a period T1 during which an exhaust valve of a first cylinder unit is in an EGR opening state overlaps with a period T2 during which an intake valve of the first cylinder unit is in an opening state is set to be lower than an average pressure P12? in the exhaust port within the EGR opening period T1 and after a lapse of the overlap period T12, or an overlapped opening time area S2 at the overlap period T12 is set to be not more than one-fourth of an opening time area S1 at the EGR opening period T1.

Abstract: A valve drive device for an engine include a valve for opening or closing an opening of a port to a combustion chamber, a valve drive member for opening or closing the valve and a drive shaft for driving the valve drive member. The device also includes a variable valve timing mechanism for continuously changing a working angle of the valve corresponding to an operation state of the engine by changing a state of drive force transmission from the drive shaft to the valve drive member. A variable valve clearance mechanism is configured such that a valve clearance that is defined as a gap between the valve and the valve drive member can be set at a first value during a first condition in which the working angle of the valve is large to a second different value during a second condition in which the working angle of the valve is small.

Abstract: A four-cycle engine (1) structured to introduce fresh air into a cylinder (1a) via an intake port (1d) opened/closed by intake valves (IN1, IN2) and suck exhaust gas back into the cylinder (1a) via an exhaust port opened/closed by exhaust valves (EX1, EX2), wherein the exhaust port has a first exhaust port (1p) and a second exhaust port (1e), and the exhaust gas is sucked in back from the first exhaust port (1p) and secondary air is sucked in from the second exhaust port (1e) to form, in the cylinder (1a), a first temperature layer (T1) at a high temperature mainly composed of the exhaust gas and a second temperature layer (T2) at a temperature lower than that of the first temperature layer (T1) mainly composed of the secondary air.

Abstract: A four-cycle engine including a blowdown pressure wave supercharging system (40) compressing and supplying exhaust gas into a second cylinder (#1) by causing a pressure wave (blowdown pressure wave) from a combustion chamber at opening of an exhaust valve of a first cylinder (#4) to act on an exhaust port (1e) of the second cylinder (#1) and during a reopen period of an exhaust valve of the second cylinder; and a mask member (50) restraining the exhaust gas (EGR gas) compressed and supplied into the second cylinder (#1) from mixing with fresh air flowing from an intake port (1d), wherein a first temperature layer (T1) at a high temperature containing a large amount of the EGR gas in the fresh air and a second temperature layer (T2) at a temperature lower than that of the first temperature layer (T1) containing a smaller amount of the EGR gas than that of the first temperature layer (T1) in the fresh air are formed in the second cylinder (#1).

Abstract: The present invention provides an engine capable of increasing an introducing amount of an EGR gas without reducing an introducing amount of a fresh air. In an engine structured to introduce fresh air and an EGR gas into a cylinder, the EGR gas is introduced into the cylinder at least at a part of a compression stroke using a pressure in a combustion chamber at least at a part of a power stroke.

Abstract: A four-stroke engine (1) structured to introduce fresh air and EGR gas into a cylinder (1a) includes a blowdown supercharging system (40) using a combustion chamber internal pressure when exhaust valves open in an expansion stroke of a first cylinder (hereinafter denoted as an exhaust blowdown pressure) for introducing EGR gas into a second cylinder from near a bottom dead center of an intake stroke to near a bottom dead center of a compression stroke of the second cylinder which is different from the first cylinder in combustion timing, and a secondary air supply system (20) supplying secondary air to an exhaust port (1e) of the second cylinder prior to arrival of the exhaust blowdown pressure at the second cylinder. The secondary air in the exhaust port and the EGR gas are supercharged into the second cylinder by the exhaust blowdown pressure from the first cylinder.

Abstract: A valve train device for an engine for driving a valve which opens and closes a valve opening of a combustion chamber comprises: a valve drive device comprising a drive member and driving force transmission mechanism. The drive force transmission mechanism is configured to transmit a driving force from the drive member to the valve. The drive force transmission mechanism comprises a transmission portion configured to transmit the driving force from the drive member to the valve and a variable portion configured to continuously change a state of the transmission portion to thereby continuously change an opening duration of the valve or the amount of valve lift. At least part of the variable portion is positioned within in the transmission portion.

Abstract: An average pressure P12 in an exhaust port at an overlap period T12 during which a period T1 during which an exhaust valve of a first cylinder unit is in an EGR opening state overlaps with a period T2 during which an intake valve of the first cylinder unit is in an opening state is set to be lower than an average pressure P12? in the exhaust port within the EGR opening period T1 and after a lapse of the overlap period T12, or an overlapped opening time area S2 at the overlap period T12 is set to be not more than one-fourth of an opening time area S1 at the EGR opening period T1.

Abstract: A rotational cam can be disposed on a camshaft rotationally driven by a crankshaft of an internal combustion engine. A swing cam can be swingable through the rotational cam. The swing cam has a rotational cam abutment portion which contacts the rotational cam and transmits driving force from the rotational cam to the swing cam. An abutment portion displacing mechanism can be provided for displacing the rotational cam abutment portion to change a relative distance between the rotational cam abutment portion and a center axis of the swing shaft. Changing the relative distance allows changing a lift and the like of a valve.

Abstract: A valve drive device for an engine include a valve for opening or closing an opening of a port to a combustion chamber, a valve drive member for opening or closing the valve and a drive shaft for driving the valve drive member. The device also includes a variable valve timing mechanism for continuously changing a working angle of the valve corresponding to an operation state of the engine by changing a state of drive force transmission from the drive shaft to the valve drive member. A variable valve clearance mechanism is configured such that a valve clearance that is defined as a gap between the valve and the valve drive member can be set at a first value during a first condition in which the working angle of the valve is large to a second different value during a second condition in which the working angle of the valve is small.

Abstract: A valve drive mechanism is provided for opening and closing a valve of an engine. The device comprises a valve drive device and a swing member pivotally supported on a swing member support shaft. The swing member is driven to pivot about the swing member support shaft by the valve drive device. A cam surface is formed on the swing member. The cam surface is configured to transfer motion of the swing member to a second member of the valve drive device. The cam surface comprises a first portion that is configured to contact the second member while the valve is moving from a closed or substantially closed position to an open position and a second portion configured to contact the second member when the valve is closed or substantially closed. A width of the second portion of the cam surface is smaller than a width of the first portion of the cam surface.

Abstract: [Technical Problem] To provide an engine capable of increasing an introducing amount of an EGR gas without reducing an introducing amount of a fresh air. [Means for Solving the Problems] In an engine structured to introduce a fresh air and an EGR gas into a cylinder, the EGR gas is introduced into the cylinder at least at a part of a compression stroke using a pressure in a combustion chamber at least at a part of a power stroke.

Abstract: A valve drive mechanism for actuating a valve of an internal combustion engine includes a cam member with a cam surface having a first portion and a second portion. A roller is configured to rotate and contact the first portion of the cam surface when the valve is in a closed position and the second portion of the cam surface with the valve is in an open position. The cam member and the roller are configured to reciprocally move relative to each other to open and close the valve. When the roller contacts the first portion, a gap within the valve drive mechanism exists between components of the valve drive mechanism on a downstream side of a force transmission path to the valve with respect to a contact point between the roller and the cam surface. A spring member urges the roller and the cam surface into contact with each other during motion between the cam member and the roller.

Abstract: A valve train device for an engine is configured to pivot a rocker arm supported on a rocker arm support shaft to drive a valve which opens and closes a valve opening formed in a combustion chamber. The device comprises a valve drive device and a swing member pivotally supported on a swing member support shaft and driven to pivot about the swing member support shaft by the valve drive device. A control arm is disposed between a swing cam surface formed on the swing member and a rocker-side surface formed on the rocker arm. The control arm is configured for transferring motion of the swing cam surface to the rocker-side surface. A displacement mechanism is provided for displacing a contact point between the control arm and the swing cam surface and a contact point between the control arm and the rocker-side surface.