3/2 Directional control valve
AssigneeRobert Bosch GmbH
InventorsAchim Brenk, Wolfgang Klenk, Uwe Gordon, Manfred Mack
Life of this patent
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Abstract
The invention relates to a 3/2-port directional-control valve for controlling the injection of fuel in a common rail injection system of an internal combustion engine, with a first switched position in which an injection nozzle is connected to a fuel return and with a second switched position in which the injection nozzle is connected to a high-pressure fuel reservoir. The beginning of the injection takes place in a pressure-controlled manner, whereas the end of the injection takes place in a stroke-controlled manner.
Claims10
A 3/2-port directional-control valve for controlling the injection of fuel in a common rail injection system of an internal combustion engine, with a control piston (44, 21, 22) guided in a housing (20), in which in a first switched position, the control piston (44, 21, 22) opens a hydraulic connection between an injector (7) and a fuel return (42, 32) and in which in a second switched position, the control piston (44, 21, 22) opens a hydraulic connection between the injector (7) and a high-pressure fuel reservoir (3), characterized in that the movement of the control piston (44, 21, 22) is transmitted to a nozzle needle (12) of the injector (7) during the transition from the second switched position into the first switched position.
The 3/2-port directional-control valve according to one of the preceding claims, characterized in that there is play in the axial direction between the control piston (44, 21, 22) and the plunger rod (53) in the first switched position.
The 3/2-port directional-control valve according to one of the preceding claims, characterized in that the control piston (44) is comprised of one part.
The 3/2-port directional-control valve according to one of the preceding claims, characterized in that the 3/2-port directional-control valve (8) is embodied as a seat/seat valve.
The 3/2-port directional-control valve according to one of the preceding claims, characterized in that the control piston (44, 21, 22) is actuated by means of a solenoid valve (35) or a piezoelectric actuator.
The 3/2-port directional-control valve according to one of the preceding claims, characterized in that it is provided for use with an injector (7), an injection nozzle, a nozzle holder combination, or a unit fuel injector.
Dependencies are inferred from the claim text.