초록 ▼

A variable valve timing type rocker arm arrangement is arranged so that, in the absence of sufficient hydraulic pressure to operate the interlocking mechanisms which switch the valve lift control from one cam follower to another, it defaults to a cam follower suited for low speed engine operation ra

A variable valve timing type rocker arm arrangement is arranged so that, in the absence of sufficient hydraulic pressure to operate the interlocking mechanisms which switch the valve lift control from one cam follower to another, it defaults to a cam follower suited for low speed engine operation rather than one which is adapted to maximize fuel economy. During engine starts (when oil pump output is inherently low) the initial low speed cam follower defaulting improves aspiration and reduces the tendency for incomplete combustion to induce the formation of smoldering deposits on the spark plug electrodes. In the event of an actual hydraulic system malfunction, the defaulting enable the engine to produce enough torque to render the vehicle drivable.

대표청구항 ▼

In an internal combustion engine a cam shaft having first, second and third cams; a rocker arm; a first cam follower which is reciprocatively mounted on said rocker arm and arranged to engage said first cam; a first interlocking device for selectively locking said first cam follower to said rocker a

In an internal combustion engine a cam shaft having first, second and third cams; a rocker arm; a first cam follower which is reciprocatively mounted on said rocker arm and arranged to engage said first cam; a first interlocking device for selectively locking said first cam follower to said rocker arm and preventing relative movement therebetween in response to a first hydraulic signal having a first predetermined level; a second cam follower which is reciprocatively mounted on said rocker arm and arranged to engage said second cam; a second interlocking device for selectively locking said second cam follower to said rocker arm and preventing relative movement therebetween in response to the absence of a second hydraulic signal having a second predetermined level; and a third cam follower which is fixedly mounted on said rocker arm and arranged to engage said third cam.