APPARATUS FOR AN INTERNAL COMBUSTION ENGINE

摘要

The invention relates to an apparatus for controlling valve movements in an internal combustion engine which has at least one inlet valve (12) and at least one exhaust valve for controlling the connection between the combustion chamber in the cylinder and an inlet system and an exhaust system respectively. A rotatable camshaft which has a cam curve comprising a rising ramp (10a) and a falling ramp (10b) is designed to interact with a valve mechanism (14) for actuation of the inlet or exhaust valve (12) under the action of a valve spring (13). The valve mechanism (14) comprises control members (21-25, 26) which allow the return movement of the valve mechanism to be controlled during the closing phase of the inlet valve (12) or the exhaust valve, independently of the falling ramp (10b) of the cam curve. The control members (21-25, 26) are arranged so that the closing of the valve can be delayed for an adjustable period of time by means of a hydraulically adjustable force counteracting the closing force of the valve spring.