초록 ▼

A control system for a four-cycle internal combustion engine controls a cam drive mechanism for an intake valve such that a cam of the cam drive mechanism maintains a valve open duration of the intake valve at a short valve open duration in response to a shift from engine operation at low speed with

A control system for a four-cycle internal combustion engine controls a cam drive mechanism for an intake valve such that a cam of the cam drive mechanism maintains a valve open duration of the intake valve at a short valve open duration in response to a shift from engine operation at low speed with low load to engine operation at low speed with high load, and the cam increases the valve open duration of the intake valve in response to a shift from engine operation at low speed with low load to engine operation at low speed with middle load that is higher than the low load but lower than the high load.

대표청구항 ▼

In a system for controlling valve open duration of an intake valve of an automobile four-cycle internal combustion engine having an exhaust valve and a throttle which opens in degrees, comprising: a cam drive mechanism including a driving shaft rotatable about a shaft axis and driven to rotate about

In a system for controlling valve open duration of an intake valve of an automobile four-cycle internal combustion engine having an exhaust valve and a throttle which opens in degrees, comprising: a cam drive mechanism including a driving shaft rotatable about a shaft axis and driven to rotate about said shaft axis in response to crankshaft rotation of the engine, and a cam in driving connection with the intake valve to open the intake valve, said cam being rotatable, about said shaft axis, relative to said driving shaft, said cam having a drive connection from said driving shaft which includes a drive member rotatable with said driving shaft, a support, and an intermediate member supported in said support for rotation about an axis thereof, said drive member being coupled with said intermediate member by a first coupling at a first position spaced from said shaft axis, and said cam being coupled with said intermediate member by a second coupling at a second position angularly spaced from the first position with respect to said shaft axis, each of said first and second coupling having a movable connection with said intermediate member to permit variation in its distance from said axis of said intermediate member during operation; said support being positionable in response to a control signal between a concentric position in which said intermediate member is concentric with said driving shaft and an eccentric position in which said axis of said intermediate member is eccentric with said shaft axis of said driving shaft; and controller means developing said control signal for positioning said support in response to varying operating conditions of the engine, the improvement wherein: said controller means generates said control signal for positioning said support to said eccentric position during engine operation at low speed with low load, said controller means generates said control signal for positioning said support to said eccentric position in response to a shift from engine operation at low speed with low load to engine operation at low speed with high load, and said controller means generates said control signal for positioning said support to said concentric position in response to a shift from engine operation at low speed with low load to engine operation at low speed with middle load that is higher than the low load but lower than the high load.