摘要:
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.
摘要:
In a variable compression ratio mechanism for an internal combustion engine employing an upper link, a lower link, and a control link, the lower link includes a crankpin bearing portion into which a crankpin is fitted, a first connecting-pin bearing portion into which a first connecting pin for the upper link is fitted, and a second connecting-pin bearing portion into which a second connecting pin for the control link is fitted. A central connecting portion is provided to connect an axial central portion of at least one of the first and second connecting-pin bearing portions to an axial central portion of the crankpin bearing portion. The central connecting portion has an axial length L1 shorter than each of an axial length L2 of the crankpin bearing portion, an axial length L3 of the first connecting-pin bearing portion, and an axial length L4 of the second connecting-pin bearing portion.
摘要:
A link mechanism of an engine includes: an upper link having a first end connected to a piston pin of a piston; a lower link connected to the upper link via an upper pin having a center, the lower link being connected to a crank pin of a crank shaft; a control shaft extending substantially in parallel with the crank shaft, the control shaft having a rotational center; and a control link including: a first end swingably connected to the control shaft, and a second end connected to the lower link. In a process of the center of the upper pin moving nearer to the axial line of the piston pin, the center of the control pin moves in the upward direction, thus inclining the lower link and allowing the center of the upper pin and the center of the piston pin to move in the downward direction.
摘要:
A control system for an internal combustion engine is provided. The engine includes a compression ratio control mechanism and an ignition timing control system. The control system comprises an engine control for controlling the compression ratio control mechanism and the ignition timing control system so that when the engine is cold, the ignition timing is retarded largely from an MBT point and the compression ratio is set higher than that obtained when the engine is cold and operated at corresponding engine rpm and engine load. A method for controlling such an internal combustion engine is also provided.
摘要:
In a rockable-cam equipped reciprocating internal combustion engine, a rockable cam is rotatably fitted on the outer periphery of an intake-valve drive shaft that is rotatable in synchronism with rotation of a crankshaft. The rockable cam oscillates within predetermined limits during rotation of the intake-valve drive shaft so as to directly push an intake-valve lifter. As viewed from an axial direction of the crankshaft, an axis of the intake-valve drive shaft is offset from a centerline of the intake-valve stem in a first direction that is normal to both the cylinder centerline and the crankshaft axis and directed from the cylinder centerline to the intake valve side. The crankshaft axis is also offset from the cylinder centerline in the first direction.
摘要:
In an internal combustion engine of variable compression ratio type, a piston control mechanism is employed which comprises a lower link rotatably disposed on a crank pin of a crankshaft of the engine, an upper link having one end pivotally connected to the lower link and the other end pivotally connected to a piston of the engine, a control link having one end pivotally connected to the lower link; and a position changing mechanism which changes a supporting axis about which the other end of the control link turns. When the piston comes up to a top dead center, a compression load is applied to the control link in an axial direction of the control link in accordance with an upward inertial load of the piston.
摘要:
A control system for an internal combustion engine is provided which comprises a compression ratio control mechanism and a control unit for controlling the compression ratio control mechanism. The control unit including an acceleration parameter obtaining section for obtaining an acceleration parameter corresponding to a change of an engine speed, an acceleration determining section for determining whether the engine is in a slow or fast acceleration state on the basis of the acceleration parameter, and a control section for controlling at least one of a compression ratio change speed at which the engine compression ratio during engine acceleration is changed and a compression ratio change start time at which a change of the engine compression ratio during engine acceleration is started, on the basis of whether the engine is in a slow or fast acceleration state. A control method is also provided.
摘要:
A reciprocating engine with a variable compression ratio mechanism is disclosed. A lubrication system of the engine is improved by controlling an oil pressure according to a compression ratio setting. The lubrication system includes various combinations of control valves and oil passages. The oil relief passage is opened at a high compression ratio setting applied to a low engine load range and is otherwise closed at a low compression ratio setting applied to a high engine load range.
摘要:
A variable compression ratio mechanism for a reciprocating engine includes a connecting rod split into upper and lower connecting rod portions linked to each other through a first connecting pin. A rockable arm is oscillatingly linked at one end to the lower connecting rod portion through a second connecting pin. A control mechanism shifts the center of oscillating motion of the rockable arm to vary a compression ratio of the engine. A piston stroke is set to be greater than two times a crank radius of a crank, irrespective of variations in the compression ratio. A linkage is dimensioned and laid out, so that its crankpin load is less than a crankpin load produced by a linkage that the crankpin is located on a perpendicular line at substantially the midpoint of a line segment between and including the centers of the first and second connecting pins.
摘要:
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. A method for controller an engine is also disclosed.