Variable valve actuator apparatus

摘要

A variable valve actuation (VVA) apparatus for an internal combustion engine comprises a drive cam fixed to a drive shaft, a valve operating (VO) cam supported by the drive shaft for pivotal motion, and a motion transmitting mechanism interconnecting the drive cam and the VO cam. The VO cam having a cam surface that extends at least from a cam lift start point to a maximum cam lift point. The cam surface includes a first section providing a ramp section, a second section providing a positive acceleration section, and a third section providing a zero acceleration section that includes a situation where acceleration continuously vary within a predetermined infinitesimal window about zero.