Abstract: An internal combustion engine which varies a compression ratio by changing a top dead center position of a piston, including an engine block, the piston disposed in the engine block, a crank shaft supported by the engine block, and a plurality of links connecting the piston and the crank shaft. A first control shaft and a second control shaft respectively are supported by the engine block, each of which has a main shaft portion rotatably supported by the engine block and an eccentric portion eccentric to the main shaft portion, the eccentric portions of the first control shaft and the second control shaft deviating from axes of the respective main shaft portions in mutually different directions when viewed from an axial direction. A plurality of control links connect any one of the plurality of links connecting the piston and the crank shaft, and the first control shaft and the second control shaft.

Abstract: An engine intake control apparatus for an engine that comprises at least one combustion chamber operatively connected to an intake port and an intake valve associated with each intake port, wherein the intake valve is adapted to open and close the intake port is disclosed herein. The intake control apparatus comprises a variable valve operating mechanism and a controller. The variable valve operating mechanism is configured and arranged to selectively change a valve closing timing and a valve lift amount of the intake valve. The controller is configured and arranged to control the variable valve operating mechanism when the engine is in a low load condition. The valve closing timing is determined such that an actual compression ratio of the engine is reduced relative to the actual compression ratio when the engine is operating in a high load condition. The valve lift amount is smaller when the engine is in the low load condition relative to the valve lift amount when the engine is in the high load condition.

Abstract: A multi-link variable compression ratio engine is provided with a crankshaft, a piston, a control shaft, a linkage, a motor and a reduction mechanism. The crankshaft moves the piston within an engine cylinder. The control shaft has an eccentric axle eccentric relative to its center-axis. The linkage operatively connects the piston to the crankshaft and the crankshaft to the eccentric axle of the control shaft. The motor rotates the control shaft so a top-dead-center position of the piston changes to vary compression ratios by changing the positions of the eccentric axle and the linkage. The reduction mechanism couples the motor to the control shaft to transmit a reduced rotation of the motor to the control shaft so a reduction ratio of a rotation angle of the motor to a rotation angle of the control shaft is less at high-compression ratios than at intermediate compression ratios.

Abstract: In an internal combustion engine, a variable lift and/or operating angle mechanism variably controls a lift and/or operating angle of an exhaust valve in accordance with a driving condition of the engine, a variable phase mechanism variably controls a phase of a lift center angle of the exhaust valve in accordance with the driving condition of the engine, a present position detecting section detects a present operating position of each of the variable lift and/or operating angle mechanism and variable phase mechanism, and a controlling section controls one of the variable lift and/or operating angle mechanism and the variable phase mechanism which operates normally in a direction in which an in-cylinder residual gas quantity becomes minimum when the other of the variable lift and/or operating angle mechanism and the variable phase mechanism has failed.

Abstract: A variable compression ratio device for an internal combustion engine comprises a control shaft (7) that varies a compression ratio of the internal combustion engine in accordance with a rotational displacement, and a linear actuator (13, 16, 17, 18). A connecting link (12) connects a first point (14) offset from a rotation axis (7a) of the control shaft (7) to an actuator rod (13) of the linear actuator (13, 16, 17, 18). Thus, a bending load acting on the actuator rod (13) is reduced, and controllability of the compression ratio is improved.

Abstract: An internal combustion engine which varies a compression ratio by changing a top dead center position of a piston, including an engine block, the piston disposed in the engine block, a crank shaft supported by the engine block, and a plurality of links connecting the piston and the crank shaft. A first control shaft and a second control shaft respectively are supported by the engine block, each of which has a main shaft portion rotatably supported by the engine block and an eccentric portion eccentric to the main shaft portion, the eccentric portions of the first control shaft and the second control shaft deviating from axes of the respective main shaft portions in mutually different directions when viewed from an axial direction. A plurality of control links connect any one of the plurality of links connecting the piston and the crank shaft, and the first control shaft and the second control shaft.

Abstract: There is provided a system for controlling an intake valve of an internal combustion engine, including a variable valve mechanism having a control shaft to continuously vary a valve lift amount of the intake valve according to a rotational angle of the control shaft and an actuator to drive the control shaft, and a control unit that controls the actuator so as to set the control shaft to a first rotational angle position at which the valve lift amount takes a first value during an engine idling period and to a second rotational angle position at which the valve lift amount takes on a second value larger than the first value to provide a required intake quantity to start the engine during a time from the beginning of an engine speed decrease period, through an engine stop period, until the completion of a cranking period of the engine.

Abstract: A variable compression ratio engine. The engine includes a piston disposed in a cylinder bore and constituting a combustion chamber, a variable compression ratio mechanism connected to the piston and causing a top dead center position of the piston to vary, an actuator connected to the variable compression ratio mechanism to actuate the variable compression ratio mechanism, and a controller connected to the actuator to control an engine state and the actuator. The controller performs operations including setting the compression ratio corresponding to a state of the engine, actuating the actuator so that the compression ratio is set, determining whether a state of the engine is either a state allowing actuation of the actuator, or a state limiting actuation of the actuator, and limiting actuation of the actuator in the state limiting actuation of the actuator.

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 engine intake control apparatus for an engine that comprises at least one combustion chamber operatively connected to an intake port and an intake valve associated with each intake port, wherein the intake valve is adapted to open and close the intake port is disclosed herein. The intake control apparatus comprises a variable valve operating mechanism and a controller. The variable valve operating mechanism is configured and arranged to selectively change a valve closing timing and a valve lift amount of the intake valve. The controller is configured and arranged to control the variable valve operating mechanism when the engine is in a low load condition. The valve closing timing is determined such that an actual compression ratio of the engine is reduced relative to the actual compression ratio when the engine is operating in a high load condition. The valve lift amount is smaller when the engine is in the low load condition relative to the valve lift amount when the engine is in the high load condition.

Abstract: An intake control apparatus for an internal combustion engine includes a variable valve operating mechanism capable of varying a lift and operation angle of an intake valve continuously and a control unit that controls an intake air amount by varying the lift and operation angle of the intake valve in accordance with an operating condition of the engine. The control unit has a learning section that learns a controlled position of the variable valve operating mechanism at a learning position that is a predetermined lift and operation angle located between a minimum value and a maximum value of the lift and operation angle that can be actually realized by the variable valve operating mechanism.

Abstract: A link mechanism usable for a variable compression ratio mechanism of an internal combustion engine includes first and second links pivotally connected by a pin inserted through cylindrical first and second pin boss portions of the first and second links. Each of the first and second pin boss portions includes a circumferentially extending first narrow section, and a circumferentially extending first wide section having an axial wall thickness greater than the axial wall thickness of the first narrow section. The wide sections of the first and second pin boss portions are overlapped in an region extending in the axial direction of the pin.

Abstract: An intake valve control apparatus for an internal combustion engine includes a first variable valve operating mechanism capable of varying an operation angle of an intake valve continuously, a second variable valve operating mechanism capable of varying a maximum lift phase of the intake valve continuously, and a controller that controls an intake air amount mainly by varying the operation angle and the maximum lift phase of the intake valve. The controller is configured to, when one of the first and second variable valve operating mechanisms is at a phase position different from a predetermined start stage phase position at engine start, correct a phase position of the other of the first and second variable valve operating mechanisms in accordance with a present phase position of the one of the first and second variable valve operating mechanisms. An intake valve control method is also provided.

Abstract: A control apparatus for an internal combustion engine includes a variable compression ratio mechanism capable of varying a compression ratio of the engine, a compression ratio setting section that sets a compression ratio to be attained by the variable compression ratio mechanism in accordance with an operating condition of the engine, a knock detecting section that detects a knock occurrence state, an ignition timing learning correcting section that determines a learning correction value of an ignition timing in accordance with the knock occurrence sate, and a compression ratio correcting section that corrects the compression ratio set by the compression ratio setting section in accordance with the learning correction value of the ignition timing. A control method is also provided.

Abstract: In an internal combustion engine, a variable lift and/or operating angle mechanism variably controls a lift and/or operating angle of an exhaust valve in accordance with a driving condition of the engine, a variable phase mechanism variably controls a phase of a lift center angle of the exhaust valve in accordance with the driving condition of the engine, a present position detecting section detects a present operating position of each of the variable lift and/or operating angle mechanism and variable phase mechanism, and a controlling section controls one of the variable lift and/or operating angle mechanism and the variable phase mechanism which operates normally in a direction in which an in-cylinder residual gas quantity becomes minimum when the other of the variable lift and/or operating angle mechanism and the variable phase mechanism has failed.

Abstract: An intake control apparatus for an internal combustion engine includes a variable valve operating mechanism capable of varying a lift and operation angle of an intake valve continuously and a control unit that controls an intake air amount by varying the lift and operation angle of the intake valve in accordance with an operating condition of the engine. The control unit has a learning section that learns a controlled position of the variable valve operating mechanism at a learning position that is a predetermined lift and operation angle located between a minimum value and a maximum value of the lift and operation angle that can be actually realized by the variable valve operating mechanism.

Abstract: There is provided a system for controlling an intake valve of an internal combustion engine, including a variable valve mechanism having a control shaft to continuously vary a valve lift amount of the intake valve according to a rotational angle of the control shaft and an actuator to drive the control shaft, and a control unit that controls the actuator so as to set the control shaft to a first rotational angle position at which the valve lift amount takes a first value during an engine idling period and to a second rotational angle position at which the valve lift amount takes on a second value larger than the first value to provide a required intake quantity to start the engine during a time from the beginning of an engine speed decrease period, through an engine stop period, until the completion of a cranking period of the engine.

Abstract: An internal combustion engine has a variable compression ratio mechanism operatable during an intake stroke to change an actual compression ratio of the engine, and is capable of correcting an amount of fuel injected into the engine in response to a change in the compression ratio.

Abstract: An intake valve control apparatus for an internal combustion engine includes a first variable valve operating mechanism capable of varying an operation angle of an intake valve continuously, a second variable valve operating mechanism capable of varying a maximum lift phase of the intake valve continuously, and a controller that controls an intake air amount mainly by varying the operation angle and the maximum lift phase of the intake valve. The controller is configured to, when one of the first and second variable valve operating mechanisms is at a phase position different from a predetermined start stage phase position at engine start, correct a phase position of the other of the first and second variable valve operating mechanisms in accordance with a present phase position of the one of the first and second variable valve operating mechanisms. An intake valve control method is also provided.