Apparatus for controlling the lift of a valve member

1. A method of controlling the lift of a valve member in a flow control valve that includes an end stop assembly having one side that faces said valve member and comprises two pieces, a plunger with one end interposed between said pieces and biasing members urging said pieces into contact with said plunger, the method comprising actuating said plunger to move said pieces from a first position in which said pieces form a first surface that contacts said valve member to allow a first lift L 1 of said valve member to a second position in which said pieces form a second surface that contacts said valve member to allow a second lift L 2 of said valve member.

2. The method of claim 1 , wherein said plunger is further actuated to move said pieces to a third position in which said pieces form a third surface that contacts said valve member to allow a third lift L 3 of said valve member.

3. An apparatus for controlling the lift of a valve member in a flow control valve comprising an end stop assembly having one side that faces said valve member, said end stop assembly comprising two pieces, a plunger with one end interposed between said pieces and biasing members urging said pieces into contact with said plunger, wherein said plunger is actuated to move said pieces from a first position to a second position, wherein in said first position said pieces of said end stop assembly form a first surface that comes into contact with said valve member to allow a first lift Ll of said valve member and in said second position said pieces form a second surface that comes into contact with said valve member to allow a second lift L 2 of said valve member.

4. The apparatus of claim 3 , wherein said plunger is actuated to move said pieces of said end stop assembly to a third position in which said pieces form a third surface that comes into contact with said valve to allow a third lift L 3 of said valve member.

5. The apparatus of claim 3 , wherein each of said pieces has an inwardly stepped end on said side of said end stop assembly which faces said valve member and the inwardly stepped ends of said pieces form together a cavity which can accommodate an end of said valve member when said valve member is lifted from its seated position and when said plunger is actuated to move said pieces.

6. The apparatus of claim 3 , wherein each of said pieces comprises an outwardly stepped end on the side of said end stop assembly which faces said valve member such that said outwardly stepped ends fit into a cavity provided in an end of said valve member which comes into contact with said end stop assembly when said valve member is lifted from its seated position and when said plunger is not actuated.

7. The apparatus of claim 3 , wherein each of said pieces comprises an inwardly stepped profile and said inwardly stepped profiles of said pieces form together a cavity which can accommodate an end of said valve member and wherein said inwardly stepped profiles of said pieces form together at least two surfaces that come into contact with said valve member when said valve member is actuated, to allow at least two discrete lifts of said valve member.

8. The apparatus of claim 3 , wherein said plunger is actuated by an electromagnetic actuator.

9. The apparatus of claim 3 , wherein said plunger is moved by an actuator along the center axis of said end stop assembly.

10. The apparatus of claim 3 , wherein said plunger is moved by an actuator along an axis that is offset from the center axis of said end stop assembly.

11. The apparatus of claim 3 , wherein said end stop assembly comprises two separate pieces which are hinged together at one side.

12. The apparatus of claim 3 , wherein said biasing members are springs.

13. The apparatus of claim 3 , wherein said end of said plunger which is interposed between said pieces has a conical shape.

14. A flow control valve comprising a valve housing having a fluid inlet and a fluid outlet with a valve member disposed therebetween; and an end stop assembly having one side that faces said valve member, said end stop assembly comprising two pieces, a plunger with one end interposed between said pieces and biasing members urging said pieces into contact with said plunger, wherein said plunger is actuated to move said pieces from a first position to a second position, wherein in said first position said pieces of said end stop assembly form a first surface that comes into contact with said valve member to allow a first lift of said valve member from a valve seat and in said second position said pieces form a second surface that comes into contact with said valve member to allow a second lift of said valve member from said valve seat.

15. The flow control valve of claim 14 , wherein said valve member is actuated by a first actuator and the plunger is actuated by a second actuator.

16. The flow control valve of claim 15 , wherein said first and said second actuators are electromagnetic actuators.

17. The flow control valve of claim 15 , wherein said flow control valve is a fuel injection valve.

18. The flow control valve of claim 14 , wherein said valve member is actuated by an electromagnetic actuator and the plunger is connected to a structure comprising a permanent magnet that is interposed in the magnetic field of said electromagnetic actuator whereby said structure is moved under the action of said magnetic field to thereby move said plunger.

19. The flow control valve of claim 18 , where the flow control valve is a fuel injection valve.

20. The flow control valve of claim 14 , wherein the flow control valve is a fuel injection valve.