FUEL INJECTION VALVE FOR INTERNAL COMBUSTION ENGINES

摘要

The invention relates to a fuel injection valve comprising a housing (1) in which pressure is applied to a nozzle needle (8), in a control chamber (28), at least indirectly with a closing force in the direction of a valve seat (10). The pressure in the control chamber (28) can be adjusted using a control valve (40) as said control chamber (28) is able to be connected to a low pressure chamber (46) via an outlet restrictor (31) and be filled with fuel at high pressure via an inlet restrictor (30). A longitudinally-displaceable control piston (29) is arranged in the control chamber (28) and divides said chamber (28) into a first control sub-chamber and a second control sub-chamber (228), the first control sub-chamber (128) being able to be connected to the low pressure chamber (46) by means of said outlet restrictor (31). A sealing surface (38) is formed on the control piston (29) and interacts with a sealing seat (39) in the control chamber (28) such that the inlet restrictor (30) is hydraulically disconnected from the second control sub-chamber (228) when the sealing surface (38) comes to rest against the sealing seat (39). Said first control sub-chamber (128) and second control sub-chamber (228) are constantly hydraulically interconnected by means of a restrictor connection (34).

主权项

1. A fuel injection valve for internal combustion engines, having a housing (1) in which a nozzle needle (8) is at least indirectly subjected, by pressure in a control chamber (28), to a closing force in a direction of a valve seat (10), wherein the pressure in the control chamber (28) is adjustable by a control valve (40) by virtue of the control chamber (28) being connectable to a low-pressure chamber (46) via an outflow throttle (31) and the control chamber (28) being configured to be filled with fuel at high pressure via an inflow throttle (30),
characterized in that, the control chamber (28) has therein a longitudinally movable control piston (29) which divides the control chamber (28) into a first control chamber part (128) and a second control chamber part (228), wherein the first control chamber part (128) is connectable to the low-pressure chamber (46) via the outflow throttle (31), and the control piston having a sealing surface (38) which interacts with a sealing seat (39) in the control chamber (28) such that, when the sealing surface (38) is in contact with the sealing seat (39), the inflow throttle (30) is hydraulically separated from the second control chamber part (228), and wherein the first control chamber part (128) and the second control chamber part (228) are permanently hydraulically connected to one another via a throttled connection (34).