Patent ID: 6029618
Filing Date: 2000-02-29
Classification: F01L

Abstract:
A variable valve actuation (VVA) apparatus in an internal combustion engine having cylinder valves, comprising:a cylinder valve having a valve closed position;valve liftera valve operating (VO) cam arranged for pivotal motion about a first predetermined axis for operating said cylinder valve via said valve lifter;a crank cam arranged for rotation about a second predetermined axis;a motion transmitting mechanism operatively interconnecting said crank cam and said VO cam,said motion transmitting mechanism having a maximum cam lift position wherein said pivotal motion of VO cam is restrained within a first extension and a minimum cam lift position wherein said pivotal motion is restrained within a second extension;said VO cam having a base circle portion, said VO cam and said valve lifter defining therebetween a valve clearance when said base circle portion assumes a predetermined relation relative to said cylinder valve;wherein, when said motion transmitting mechanism is in said minimum lift position, the VO cam provides variable cam lift values during said pivotal motion thereof, said variable cam lift values having the maximum cam lift that is greater than zero and less than said valve clearance.