Patent ID: 6296197
Filing Date: 2001-10-02
Classification: F02M

Abstract:
An injection valve for a fuel injection system for internal combustion engines, comprising means for multistage control of an effective cross section of at least one injection opening (42), these means having a spring/stop system, which when a control valve (4) opens allows a valve tappet (5) to move a first axial stroke (46), counter to a compressive force of a first compression spring (10) which movement is limited by a primary stop (37) that is located on an axially movable adapter (30), the axially movable adapter (30) is urged by a second compression spring (31) onto a stop (32) and an axial mobility of the adapter counter to the compressive force of the second compression spring (31) allows an additional second axial stroke (47) of the valve tappet (5), which is limited by a structural end stop (39) of the housing, the control valve (4) controls a control chamber (12), a pressure of the control chamber determines a position of a valve shaft (2) of a metering valve (1); and the valve tappet (5) is urged in a closing direction of the control valve (4) by the first compression spring (10) braced against the housing (9) of the injection valve and movable in the axial direction directly or indirectly by a piezoelectric actuator (3), and in the closed state of the control valve (4) the spring force of the first compression spring (10) is less than that of the second compression spring (31), in which the first compression spring (10) and the second compression spring (31) are disposed, coaxially with the valve tappet (5), in the region between the piezoelectric actuator (3) and a valve head (44) of the control valve (4).