초록 ▼

The invention relates to a fuel injection valve for intermittent fuel injection into the combustion chamber of internal combustion engines. A needle-shaped injection valve member (34) is arranged in the high-pressure fuel chamber (30) adjacent to the injection valve seat (32), said injection valve m

The invention relates to a fuel injection valve for intermittent fuel injection into the combustion chamber of internal combustion engines. A needle-shaped injection valve member (34) is arranged in the high-pressure fuel chamber (30) adjacent to the injection valve seat (32), said injection valve member co-operating with the injection valve seat (32) and defining, in a piston-type manner, the cylinder chamber (36) which is connected to the high-pressure inlet (26). The booster piston (28) is controlled by means of the control valve (34) embodied as a flat seat valve, increasing the pressure of the fuel in the high-pressure fuel chamber (30) for an injection, and thus lifting the injection valve member from the injection valve seat. In this way, the injection is carried out with increased pressure.

대표청구항 ▼

The invention claimed is: 1. A fuel injection valve for intermittent fuel injection into the combustion chamber of an internal combustion engine, having an injection valve seat adjoining a high-pressure fuel chamber, a needle-shaped injection valve member, which on the one hand interacts with the i

The invention claimed is: 1. A fuel injection valve for intermittent fuel injection into the combustion chamber of an internal combustion engine, having an injection valve seat adjoining a high-pressure fuel chamber, a needle-shaped injection valve member, which on the one hand interacts with the injection valve seat and on the other in the manner of a piston defines a cylinder chamber connected to a control pressure inlet for the fuel at least during the injection sequence, a booster piston acting as a differential piston, which on the control pressure side defines a piston drive chamber, which via a control valve, controlled by means of an electrically activated actuator, can be connected to and separated from the control pressure inlet, and which on the high-pressure side defines a piston output chamber connected to the high-pressure fuel chamber, wherein the control valve is embodied as a flat seat valve and a control valve member is of disk-like design and interacts with a control valve seat, in the area of which an at least approximately annular inlet groove, connected to the control pressure inlet, is arranged. 2. The fuel injection valve as claimed in claim 1, wherein the cylinder chamber is permanently connected to the control pressure inlet. 3. A fuel injection valve for intermittent fuel injection into the combustion chamber of an internal combustion engine, having an injection valve seat adjoining a high-pressure fuel chamber, a needle-shaped injection valve member, which on the one hand interacts with the injection valve seat and on the other in the manner of a piston defines a cylinder chamber connected to a control pressure inlet for the fuel at least during the injection sequence, a booster piston acting as a differential piston, which on the control pressure side defines a piston drive chamber, which via a control valve, controlled by means of an electrically activated actuator, can be connected to and separated from the control pressure inlet, and which on the high-pressure side defines a piston output chamber connected to the high-pressure fuel chamber, wherein the control valve is embodied as a flat seat valve and the control valve has a control valve member, which is arranged in a control valve chamber, which is connected to a low-pressure chamber, at least when the control valve is closed. 4. The fuel injection valve as claimed in claim 3, wherein the control valve member is of disk-like design and interacts with a control valve seat, in the area of which an at least approximately annular inlet groove, connected to the control pressure inlet, is arranged. 5. The fuel injection valve as claimed in claim 4, wherein an outlet opening connected to the piston drive chamber is arranged in the area of the control valve seat, concentrically with and at a distance from the inlet groove. 6. The fuel injection valve as claimed in claim 4, wherein the control valve member is arranged on an operating stem, guided in a sliding fit and interacting with the actuator. 7. The fuel injection valve as claimed in claim 4, wherein the control valve member is connected to a compensating piston defining a compensating pressure chamber connected to the control pressure inlet. 8. The fuel injection valve as claimed in claim 1, wherein the piston output chamber is connected via a non-return valve to the high-pressure inlet. 9. The fuel injection valve as claimed in claim 1, wherein the piston output chamber is connected via a non-return valve to an inlet for the fuel to be injected. 10. The fuel injection valve as claimed in claim 1, wherein the piston drive chamber is connected via a restriction passage to a low-pressure outlet. 11. The fuel injection valve as claimed in claim 1, wherein the piston drive chamber is connected via a passage to a low-pressure outlet, and the low-pressure outlet is preferably closed by the control valve member when the control valve is open. 12. The fuel injection valve as claimed in claim 1, wherein the booster piston is stepped on the control pressure side and the piston drive chamber is at least approximately defined by reciprocal stepping. 13. The fuel injection valve as claimed in claim 1, wherein the actuator is embodied as a piezoactuator. 14. The fuel injection valve as claimed in claim 1, wherein the control valve has a control valve seat formed on an end face of a control valve seat body, and a washer of selectable thickness is arranged between the actuator and the control valve seat body. 15. The fuel injection valve as claimed in claim 3, wherein the piston output chamber is connected via a non-return valve to the high-pressure inlet. 16. The fuel injection valve as claimed in claim 3, wherein the piston output chamber is connected via a non-return valve to an inlet for the fuel to be injected. 17. The fuel injection valve as claimed in claim 3, wherein the piston drive chamber is connected via a restriction passage to a low-pressure outlet. 18. The fuel injection valve as claimed in claim 3, wherein the booster piston is stepped on the control pressure side and the piston drive chamber is at least approximately defined by reciprocal stepping. 19. The fuel injection valve as claimed in claim 11, wherein the booster piston is stepped on the control pressure side and the piston drive chamber is at least approximately defined by reciprocal stepping. 20. The fuel injection valve as claimed in claim 3, wherein the actuator is embodied as a piezoactuator. 21. The fuel injection valve as claimed in claim 11, wherein the actuator is embodied as a piezoactuator.