Patent ID: 6886532

Claim:
An intake system of an internal combustion engine, comprising: a collector fixedly connected directly to at least one of a side wall of a cylinder head and a collector mounting bracket hermetically covering perimeters of intake-port opening end portions of a plurality of intake ports opening through the side wall; a plurality of intake-manifold branches respectively communicating with the plurality of intake ports and protruded into an interior space of the collector; a variable valve actuation system that continuously variably adjusts a valve lift characteristic of an intake valve, the variable valve actuation system comprising a first variable valve actuation mechanism capable of continuously variably adjusting the working angle and the lift of the intake valve; a control unit configured to be electronically connected to the variable valve actuation system for variably controlling an intake-air quantity through the variable valve actuation system; wherein the first variable valve actuation mechanism comprises: a drive shaft; an eccentric cam driven by the drive shaft; a first link fitted to an outer periphery of the eccentric cam to permit relative rotation of the first link to the eccentric cam; a control shaft arranged parallel to the drive shaft and comprising a control cam whose axis is eccentric to an axis of the control shaft; a rocker arm fitted to an outer periphery of the control cam to permit relative rotation of the rocker arm to the control cam, wherein the rocker arm is connected at one end to the first link so that an oscillating motion of the rocker arm is produced through the first link; and a rockable cam rotatably supported on the drive shaft, connected to another end of the rocker arm via a second link, and configured to be in abutted engagement with a valve lifter of the intake valve so that the valve lifter is pushed by cam action of the rockable cam oscillating through the rocker arm; wherein the working angle and the lift of the intake valve are simultaneously adjusted by varying a center of rotation of the control cam of the control shaft.