초록 ▼

The fuel injection system has one high-pressure fuel pump (10) with a pump work chamber (22) and one fuel injection valve (12), communicating with the pump work chamber, for each cylinder of the engine. The fuel injection valve (12) has a first injection valve member (28), by which at least a first

The fuel injection system has one high-pressure fuel pump (10) with a pump work chamber (22) and one fuel injection valve (12), communicating with the pump work chamber, for each cylinder of the engine. The fuel injection valve (12) has a first injection valve member (28), by which at least a first injection opening (32) is controlled, and which is movable in an opening direction (29) counter to a closing force by the pressure generated in the pump work chamber (22). Inside the hollow first injection valve member (28), a second injection valve member (128) is guided displaceably, by which at least a second injection opening (132) is controlled, and which is movable by the pressure prevailing in the pressure chamber (40) in an opening direction (29) counter to a closing force; the second injection valve member (128) is acted upon at least indirectly by the pressure prevailing in a fuel-filled control chamber (50), which pressure is generated, as a function of operating parameters of the engine, by a feed pump (52) such that the second injection valve member (128) either remains in its closed position, or can open.

대표청구항 ▼

1. In a fuel injection system for an internal combustion engine, having one high-pressure fuel pump (10) and one fuel injection valve (12), communicating with it, for each cylinder of the engine, in which the high-pressure fuel pump (10) has a pump piston (18), driven in a reciprocating motion by th

1. In a fuel injection system for an internal combustion engine, having one high-pressure fuel pump (10) and one fuel injection valve (12), communicating with it, for each cylinder of the engine, in which the high-pressure fuel pump (10) has a pump piston (18), driven in a reciprocating motion by the engine, which piston defines a pump work chamber (22) that communicates with a pressure chamber (40) of the fuel injection valve (12), and the fuel injection valve (12) has at least one first injection valve member (28), by which at least one first injection opening (32) is controlled and which is movable in an opening direction (29), counter to a closing force, by the pressure prevailing in the pressure chamber (40), and having a first electrically controlled control valve (23), by which a communication of the pump work chamber (22) with a relief chamber is controlled, the fuel injection valve (12) has a second injection valve member (128), guided displaceably inside the hollow first injection valve member (28), by means of which second injection valve member at least one second injection opening (132) is controlled, and which second injection valve member is movable in an opening direction (29) counter to a closing force by the pressure prevailing in the pressure chamber; and wherein the second injection valve member (128) is acted upon at least indirectly by the pressure prevailing in a fuel-filled control chamber (50; 246), which pressure is generated by a pressure source (52) as a function of operating parameters of the engine, as a result of which the opening pressure of at least the second injection valve member (128) is variable.2. The fuel injection system of claim 1, wherein a common pressure source (52) is provided for all the cylinders of the engine.3. The fuel injection system of claim 2, wherein the second injection valve member (128) is acted upon by the pressure prevailing in the control chamber (50), at least indirectly counteracting the closing force, so that with increasing pressure in the control chamber (50), the closing force acting on the second injection valve member (128) is reduced.4. The fuel injection system of claim 3, further comprising a first closing spring (44) generating the closing force on the first injection valve member (28); and wherein the first injection valve member (28), or a brace (47) of its first closing spring (44) is acted upon at least indirectly by the pressure in the control chamber (50), reinforcing the closing spring (44), so that with increasing pressure in the control chamber (50), the closing force acting on the first injection valve member (28) is increased.5. The fuel injection system of one of claim 4, wherein at low load and/or low engine rpm, by means of the pressure source (52), a slight pressure in the control chamber (50) is generated such that the second injection valve member (128) remains in a closed position, and only the first injection valve member (28) opens and uncovers the at least one first injection opening (32); and that at a high load and/or high engine rpm, by means of the pressure source (52), a high pressure in the control chamber (50) is generated such that so that in addition the second injection valve member (128) also opens and uncovers the at least one second injection opening (132).6. The fuel injection system of claim 3, further comprising a second closing spring (144) generating the closing force on the second injection valve member (128), the second injection valve member (128) being braced on the second closing spring (144) via a piston (147), which with its face end remote from the second closing spring (144) defines the control chamber (50).7. The fuel injection system of one of claim 3, wherein at low load and/or low engine rpm, by means of the pressure source (52), a slight pressure in the control chamber (50) is generated such that the second injection valve member (128) remains in a closed position, and only the first injection valve member (28) opens and uncovers the at least one first injection opening (32); and that at a high load and/or high engine rpm, by means of the pressure source (52), a high pressure in the control chamber (50) is generated such that so that in addition the second injection valve member (128) also opens and uncovers the at least one second injection opening (132).8. The fuel injection system of claim 2, wherein the second injection valve member (128) is acted upon by the pressure prevailing in the control chamber (246), at least indirectly reinforcing the closing force in the closing direction, so that with increasing pressure in the control chamber (246), the closing force acting on the second injection valve member (128) is increased.9. The fuel injection system of claim 8, wherein at low load and/or low engine rpm, by means of the pressure source (52), a high pressure in the control chamber (246) is generated such that the second injection valve member (128) remains in its closed position, and only the first injection valve member (28) opens and uncovers the at least one first injection opening (32), and wherein at high load and/or high engine rpm, by means of the pressure source (52), a slight pressure in the control chamber (246) is generated such that in addition the second injection valve member (128) also opens and uncovers the at least one second injection opening.10. The fuel injection system of claim 1, wherein the second injection valve member (128) is acted upon by the pressure prevailing in the control chamber (50), at least indirectly counteracting the closing force, so that with increasing pressure in the control chamber (50), the closing force acting on the second injection valve member (128) is reduced.11. The fuel injection system of claim 10, further comprising a first closing spring (44) generating the closing force on the first injection valve member (28); and wherein the first injection valve member (28), or a brace (47) of its first closing spring (44) is acted upon at least indirectly by the pressure in the control chamber (50), reinforcing the closing spring (44), so that with increasing pressure in the control chamber (50), the closing force acting on the first injection valve member (28) is increased.12. The fuel injection system of claim 11, further comprising a second closing spring (144) generating the closing force on the second injection valve member (128), the second injection valve member (128) being braced on the second closing spring (144) via a piston (147), which with its face end remote from the second closing spring (144) defines the control chamber (50).13. The fuel injection system of one of claim 11, wherein at low load and/or low engine rpm, by means of the pressure source (52), a slight pressure in the control chamber (50) is generated such that the second injection valve member (128) remains in a closed position, and only the first injection valve member (28) opens and uncovers the at least one first injection opening (32); and that at a high load and/or high engine rpm, by means of the pressure source (52), a high pressure in the control chamber (50) is generated such that so that in addition the second injection valve member (128) also opens and uncovers the at least one second injection opening (132).14. The fuel injection system of claim 10, further comprising a second closing spring (144) generating the closing force on the second injection valve member (128), the second injection valve member (128) being braced on the second closing spring (144) via a piston (147), which with its face end remote from the second closing spring (144) defines the control chamber (50).15. The fuel injection system of claim 14, wherein at low load and/or low engine rpm, by means of the pressure source (52), a slight pressure in the control chamber (50) is generated such that the second injection valve member (128) remains in a closed position, and only the first injection valve member (28) opens and uncovers the at least one first injection opening (32); and that at a high load and/or high engine rpm, by means of the pressure source (52), a high pressure in the control chamber (50) is generated such that so that in addition the second injection valve member (128) also opens and uncovers the at least one second injection opening (132).16. The fuel injection system of one of claim 10, wherein at low load and/or low engine rpm, by means of the pressure source (52), a slight pressure in the control chamber (50) is generated such that the second injection valve member (128) remains in a closed position, and only the first injection valve member (28) opens and uncovers the at least one first injection opening (32); and that at a high load and/or high engine rpm, by means of the pressure source (52), a high pressure in the control chamber (50) is generated such that so that in addition the second injection valve member (128) also opens and uncovers the at least one second injection opening (132).17. The fuel injection system of claim 1, wherein the second injection valve member (128) is acted upon by the pressure prevailing in the control chamber (246), at least indirectly reinforcing the closing force in the closing direction, so that with increasing pressure in the control chamber (246), the closing force acting on the second injection valve member (128) is increased.18. The fuel injection system of claim 17, wherein at low load and/or low engine rpm, by means of the pressure source (52), a high pressure in the control chamber (246) is generated such that the second injection valve member (128) remains in its closed position, and only the first injection valve member (28) opens and uncovers the at least one first injection opening (32), and wherein at high load and/or high engine rpm, by means of the pressure source (52), a slight pressure in the control chamber (246) is generated such that in addition the second injection valve member (128) also opens and uncovers the at least one second injection opening.19. The fuel injection system of claim 1, wherein by means of the pressure source (52), at a slight pumping stroke of the pump piston (18) for a fuel preinjection, a pressure in the control chamber (50; 246) is generated such that the second injection valve member (128) remains in its closed position, and only the first injection valve member (28) opens and uncovers the at least one first injection opening (32); and wherein by means of the pressure source (52), with an increasing supply stroke of the pump piston (18) for a main fuel injection, a pressure in the control chamber (246) is generated such that in addition the second injection valve member (128) also opens and uncovers the at least one second injection opening (132).20. The fuel injection system of claim 11, wherein by means of the pressure source (52), at the onset of a main fuel injection, a pressure in the control chamber (50; 246) is generated such that the second injection valve member (128) remains in its closed position and only the first injection valve member (28) opens and uncovers the at least one first injection opening (32); and wherein in the further course of the main fuel injection, by means of the pressure source (52), a pressure in the control chamber (50; 246) is generated such that in addition the second injection valve member (128) also opens and uncovers the at least one second injection opening (132).