Internal combustion engine having an intake/exhaust valve assembly and

Abstract

An intake/exhaust valve assembly of an internal combustion engine, comprising a reciprocating valve movable into and out of the combustion chamber, a cam driven for rotation by the crankshaft, a cam follower intervening between the cam and the reciprocating valve, a control plunger slidable between first and second axial positions in a main axial bore and defining a pressure-acting chamber in the main axial bore, the control plunger being formed with a passageway open at one end to the pressure-acting chamber and at the other end through the peripheral wall of the plunger, the plunger being operative and inoperative to bear the force transmitted from the cam through the cam follower when the control plunger is in the first and second axial positions, respectively, a check valve providing one-way communication from the passageway in the plunger to the pressure-acting chamber, a fluid discharge chamber open to the pressure-acting chamber, a fluid outlet passageway communicable with the fluid discharge chamber, a pressure-release valve having a condition providing communication between the fluid discharge chamber and the fluid outlet passageway and a condition blocking the communication, a valve actuator to actuate the pressure-release valve under predetermined conditions of the engine, and fluid supply means communicable with the passageway in the control plunger.