VALVE OPERATION CHANGE-OVER DEVICE ON INTERNAL- COMBUSTION ENGINE

摘要

PURPOSE:To prevent a rocker arm from wear and damage by providing an actuator which releases the stopper of another actuator serving to change over the performance characteristics of a valve and controlling the releasing actuator at a specific discharge stroke of an oil pump so as to make optimum selection of the change-over timing. CONSTITUTION:An actuator 1 which moves a rocker arm to change over performance characteristics of a valve is prevented from displacement by making engagement with a stopper 12 pressed by another actuator 13 to which the pressure of oil in an accumulator 9 and the force of a spring are applied. The port 6c of an oil pump 6 is then communicated with a port 15a or 15b so that the pressure of oil in a pump housing 6a becomes equal to that of oil in the accumulator 9. However, the pressure of oil in the pump housing 6 is increased at a specific discharge stroke where the communication is shut off so that the high pressure oil is sent into a stopper releasing actuator 14. Engagement of the actuator 1 with the stopper 12 is therefore released, hence allowing the actuator 1 to be displaced.