FUEL INJECTION DEVICE

Abstract

The invention relates to a fuel injection device (100) for a compression-ignition engine, comprising a first storage unit (20) which can be supplied with fuel by at least one high-pressure pump (16), the first storage unit (20) being arranged preferably inside the high-pressure pump (16), a first connecting line (26) from the first storage unit (20) to a second storage unit (30), and a second connecting line (40) from the second storage unit (30) to a fuel injector (50).

Claims

1. A fuel injection device (100) for a compression-ignition engine, the fuel injection device comprising a first storage unit (20) configured to be supplied with fuel by at least one high-pressure pump (16), a first connecting line (26) from the first storage unit (20) to a second storage unit (30), and a second connecting line (40) from the second storage unit (30) to a fuel injector (50), wherein a third storage unit (42) is arranged inside a housing (52) of the fuel injector (50), in which third unit an injection element (46) is arranged in a manner so as to be moved by lifting, and wherein the storage volume of the third storage unit (42) is a volume, corresponding to a plurality of nominal injection amounts of the fuel injector (50).

2. The fuel injector according to claim 1, wherein the storage volumes of the second storage unit (30) and the third storage unit (42) together correspond to between 20 times and 150 times the nominal injection amount of the fuel injector (50).

3. The fuel injector according to claim 1, wherein the storage volume of the first storage unit (20) corresponds to between 20 times and 40 times the nominal injection amount of the fuel injectors (50) connected to the first storage unit (20).

4. The fuel injector according to claim 1, wherein a first throttle device (36) restricting a flow rate is arranged between the first storage unit (20) and the second storage unit (30), and a second throttle device (38) restricting a flow rate is arranged between the second storage unit (30) and the third storage unit (42).

5. The fuel injector according to claim 4, wherein the first throttle device (36) forms a common assembly unit (32) with the second storage unit (30).

6. A fuel injector according to claim 4, wherein the second throttle device (38) forms a common assembly unit (32) with the second storage unit (30) or the second throttle device (38) is arranged inside the fuel injector (50).

7. The fuel injector according to claim 1, wherein A resonator throttle (48) is arranged in a flow path between the third storage unit (42) and an injection element (46) of the fuel injector (50).

8. The fuel injector according to claim 1, wherein a flow restrictor (34) is arranged upstream of the second storage unit (30).

9. The fuel injector according to claim 8, wherein the flow restrictor (34) forms a common assembly unit (32) with the second storage unit (30).

10. The fuel injector according to claim 1, wherein a plurality of second storage units (30) and a plurality of fuel injectors (50) are provided.

11. A fuel injection device (100) for a compression-ignition engine, the fuel injection device comprising a first storage unit (20) configured to be supplied with fuel by at least one high-pressure pump (16), the first storage unit (20) being arranged inside the high-pressure pump (16), a first connecting line (26) from the first storage unit (20) to a second storage unit (30), and a second connecting line (40) from the second storage unit (30) to a fuel injector (50), wherein a third storage unit (42) is arranged inside a housing (52) of the fuel injector (50), which third unit is arranged separately from a high-pressure chamber (44), in which an injection element (46) is arranged in a manner so as to be moved by lifting, and wherein the storage volume of the third storage unit (42) is a volume, corresponding to a plurality of nominal injection amounts of the fuel injector (50).

12. The fuel injector according to claim 11, wherein the storage volumes of the second storage unit (30) and the third storage unit (42) together correspond to between 20 times and 150 times the nominal injection amount of the fuel injector (50).

13. The fuel injector according to claim 12, wherein the storage volume of the first storage unit (20) corresponds to between 20 times and 40 times the nominal injection amount of the fuel injectors (50) connected to the first storage unit (20).

14. The fuel injector according to claim 13, wherein a first throttle device (36) restricting a flow rate is arranged between the first storage unit (20) and the second storage unit (30), and a second throttle device (38) restricting a flow rate is arranged between the second storage unit (30) and the third storage unit (42).

15. The fuel injector according to claim 14, wherein the first throttle device (36) forms a common assembly unit (32) with the second storage unit (30).

16. A fuel injector according to claim 15, wherein the second throttle device (38) forms a common assembly unit (32) with the second storage unit (30) or the second throttle device (38) is arranged inside the fuel injector (50).

17. The fuel injector according to claim 16, wherein A resonator throttle (48) is arranged in a flow path between the third storage unit (42) and an injection element (46) of the fuel injector (50).

18. The fuel injector according to claim 1, wherein a flow restrictor (34) is arranged upstream of the second storage unit (30).

19. The fuel injector according to claim 8, wherein the flow restrictor (34) forms a common assembly unit (32) with the second storage unit (30).

20. The fuel injector according to claim 1, wherein a plurality of second storage units (30) and a plurality of fuel injectors (50) are provided.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0014] In a system diagram, FIG. 1 shows a fuel injection device according to the present invention for a compression-ignition engine.

DETAILED DESCRIPTION

[0015] FIG. 1 shows the essential components of a fuel injection device 100 according to the invention for a compression-ignition, multi-cylindrical engine. The fuel injector 100 comprises a fuel reservoir 10 connected to a high-pressure pump 16 via a pre-feed pump 12 and a filter element 14. The high-pressure pump 16 serves to provide a system pressure of greater than 1500 bar, preferably greater than 2000 bar. For this purpose, the high-pressure pump 16 comprises, in a manner known per se, a plurality of pressure booster units 18 that convey the high-pressure fuel into the region of a first storage unit 20. The first storage unit 20 serves to supply a plurality of fuel injectors 50 simultaneously.

[0016] In the illustrated embodiment, the first storage unit 20 together with the high-pressure pump 16 forms a common assembly unit 24, and the first storage unit 20 is integrated inside the high-pressure pump 16.

[0017] At least indirectly, a high-pressure line 26 leads away from the first storage unit 20, from which line a respective branch 28 for each fuel injector 50 extends. Each branch 28 is connected to a second storage unit 30, in which the high-pressure fuel is temporarily stored. The second storage unit 30 is in particular arranged close to the cylinder of the engine. The second storage unit 30 is part of an assembly unit 32 comprising, for example, a flow restrictor 34. However, the flow restrictor 34 can also be embodied as a unit that is independent or separate from the assembly unit 32.

[0018] A first flow restrictor 36 is arranged in the flow path upstream of the second storage unit 30. In the illustrated exemplary embodiment, the first throttle device 36 is a component of the assembly unit 32. A second throttle device 38 is provided in the flow path between the second storage unit 30 and the fuel injector 50. The second throttle device 38, in the illustrated exemplary embodiment, is also part of a component of the assembly unit 32, but it can also be a component of or integrated inside the fuel injector 50.

[0019] A second connecting line 40 is arranged between the assembly unit 32 or second storage unit 30 and a housing 52 of the fuel injector 50. The second connecting line 40 serves to supply fuel to the fuel injector 50. In particular, the second supply line 40 opens into a third storage unit 42 arranged inside the housing 52. The third storage unit 42 is formed inside the housing 52 of the fuel injector 50. The third storage unit 42 leads to a high-pressure chamber 44 in which an injector pin 46, which can be moved up and down, is arranged as an injection element.

[0020] Using an actuator of fuel injector 50, which is not shown in detail and which enables the injector pin 46 to be lifted, fuel is injected into the combustion chamber of the engine in a manner known per se. Furthermore, it can be discerned that a resonator throttle 48 is arranged between the third storage unit 42 and the high-pressure chamber 44.

[0021] Essential for the desired functionality of the fuel injector device 100 or the fuel injectors 50 is that the volumes of the first storage unit 20, the second storage unit 30, and the third storage unit 42 are configured in a special manner relative to a nominal injection amount of the fuel injector 50. A nominal injection amount of the fuel injector 50 is understood to mean the injection amount that is injected into the cylinder of the engine at the nominal power and nominal speed of the engine per power stroke. With respect to the size of the individual fuel volumes, it is provided that the storage volume of the first storage unit 20 is between 20 times and 40 times, typically about 30 times, the nominal injection amount of the fuel injectors 50 connected to the first storage unit 20. Furthermore, the storage volumes of the second storage unit 30 and the third storage unit 42 together are 20 to 150 times, preferably 50 to 80 times, more preferably about 65 times the nominal injection amount of a fuel injector 50.

[0022] The fuel injection device 100 or fuel injectors 50 described thus far can be changed or modified in a variety of ways without departing from the idea of the invention.