摘要:
In an internal combustion engine with two cylinder banks, each cylinder bank having a cylinder head mounting thereon a valve operating device enabling both valve timing and valve lift characteristic to be varied, each valve operating device drives an engine valve through an eccentric cam, a substantially ring-shaped link, a rocker arm, a rod-shaped link, and a rockable cam, by rotation of a drive shaft. A control shaft varies the attitude of the rocker arm via a control cam by rotary motion thereof, in order to change a valve lift characteristic of the engine valve. As viewed in the same axial direction, a lifting direction of the rockable cam relative to a rotational direction of the drive shaft is the same in the two cylinder banks.
摘要:
A VVA apparatus for an internal combustion engine includes a intake valve, and an alteration mechanism which variably controlling lift characteristics of the intake valve in accordance with the engine operating conditions, wherein the valve lift characteristics include a ramp period which is shorter in the range of medium lift amount than in the range of small lift amount and the range of large lift amount.
摘要:
In an internal combustion engine with two cylinder banks, each cylinder bank having a cylinder head mounting thereon a valve operating device enabling both valve timing and valve lift characteristic to be varied, each valve operating device drives an engine valve through an eccentric cam, a substantially ring-shaped link, a rocker arm, a rod-shaped link, and a rockable cam, by rotation of a drive shaft. A control shaft varies the attitude of the rocker arm via a control cam by rotary motion thereof, in order to change a valve lift characteristic of the engine valve. As viewed in the same axial direction, a lifting direction of the rockable cam relative to a rotational direction of the drive shaft is the same in the two cylinder banks.
摘要:
A VVA apparatus for an internal combustion engine includes a intake valve, and an alteration mechanism which variably controlling lift characteristics of the intake valve in accordance with the engine operating conditions, wherein the valve lift characteristics include a ramp period which is shorter in the range of medium lift amount than in the range of small lift amount and the range of large lift amount.
摘要:
A main rocker arm which is pivotally mounted on a rocker shaft has one or more sub-rocker arms pivotally mounted thereon. The main rocker arm is arranged to synchronously open and close two poppet valves. Each of the sub-rocker arms can be selectively locked to the main one by way of hydraulically operated plunger arrangements. The main rocker arm is provided with a roller type cam follower which follows a low speed cam. The sub-rocker arms are provided with followers which engage high or very high speed cams. Lost motion springs which maintain the sub-rocker arms in contact with the cams are mounted on the main rocker arm.
摘要:
In a variable valve actuation system of an internal combustion engine employing a variable valve actuator (1,2) capable of variably adjusting at least intake valve (4) closure timing depending on engine operating conditions, a processor (22) of a control unit is programmed to phase-advance the intake valve closure timing (IVC) to a predetermined timing value after a piston top dead center position and before a piston bottom dead center position on intake stroke during at least one of an engine starting period and an engine stopping period. The variable valve actuator (1,2) includes a biasing device (31,55-56) by which the intake valve closure timing is permanently biased toward the predetermined timing value.
摘要:
A valve operating apparatus for an internal combustion engine including a drive cam (4), first and second swing cams (5), first and second motion transmission mechanisms (7) and first and second valve actuating members (6). The first and second swing cams (5) are provided with identical swing motion characteristic with respect to a rotation angle of the drive cam (4) through the first and second motion transmission mechanisms (7). The first swing cam (5) and the first valve actuating member (6) cooperate with each other to provide a valve lift amount of the engine valve (2) for the first group of cylinders with respect to a swing angle of the first swing cam (5) which is identical to a valve lift amount of the engine valve (2) for the second group of cylinders with respect to a swing angle of the second swing cam (5).