Variable drive for double tappet valve - has raised extension of one tappet fitting inside other

摘要

The lift valve (3) has an inner cup tappet (10) acted on by a cam (8) and an enveloping outer tappet (11) operated by a second cam (9) synchronised with the first. The outer tappet has a buffer area (12) for the spring loaded valve. An external feed line (21) containing a control valve (22) delivers pressure medium to a pressure chamber (16) sealed on all sides by the two tappets (10, 11). The buffer area (12) is formed by a raised portion (13) of the outer tappet running inside the inner tappet (10) in the direction of the cams (8, 9). The pressure chamber (16), which extends between this portion and the base of the inner tappet (10), is permanently connected to the external pressure medium supply (21) by flow routes (20) in the outer tappet (11). USE/ADVANTAGE - Reduces overall length of valve drive.