Fuel injection valve with piezoelectric or magnetostrictive actuator, has hydraulic coupling valve closure body and seat surface urged pressed together by spring

摘要

A coupling valve closure body (41) and a coupling valve seat surface (42) cooperate via a coupling spring (38) to form a coupling valve seat seal (43). The pressure region (37) of the hydraulic coupling (35a) between the actuator (14) and valve needle (2) is connected to the fuel supply (44) via a supply bore (36) in the piston (33) or cylinder support (35) and via the coupling valve seat seal. The latter has a cross-sectional surface which is smaller than the cross-sectional surface of the piston. The actuator operates a valve closure body (3) on the valve needle via a hydraulic coupling, in order to form a valve seat seal (6). The hydraulic coupling comprises a cylinder support (35) and a piston housed inside the cylinder (34), which defines a pressure region and tensions a coupling spring between the piston and cylinder, in order to push the piston out of the cylinder.