Robert Boschgmbh

Marco Vorbach

Michael Huebel

Martin Mueller

Alexander Hantke

Christoph Haible

A valve for metering a flowing medium, e.g., an injection valve for fuel-injection systems of internal combustion engines, is provided. In an embodiment, the valve has a sealing seat formed by a valve seat and a sealing head of a valve member able to be driven to execute lift motions. The valve has a plurality of spray orifices having hole-entry openings situated downstream from the sealing seat and sealable by the sealing seat. The valve has flow-through channels situated upstream from the sealing seat, which extend parallel to each other and discharge in front of the sealing seat. In order to achieve a unified upstream flow approach of all hole-entry openings of the spray orifices, e.g., if the number of spray orifices and flow-through channels differs, an upstream-flow shaper having at least one flow-through opening is situated between sealing seat and hole-entry openings of the spray orifices.

Valve for metering a flowing medium

A fuel injector for internal combustion engines is provided, which has a valve seat member, bordering a valve chamber, having a valve seat and spray orifices and a central blind-end bore as well as a valve member that is able to be driven to cause a lift motion having a closing head, which, together with a valve seat, forms a sealing seat lying upstream of the spray orifices. In order to prevent an underpressure developing in the blind-end bore in the closing phase of the sealing seat, and a partial return flow of the fuel connected with it, the closing head of the valve member is provided, at its end face facing towards the valve seat member, with a plunger sticking out from closing head, which has a shape adjusted to the contour of the blind-end bore, and dips into the blind-end bore when the sealing seat is closed.

Fuel injector for internal combustion engines

A valve for injecting fuel includes a valve carrier having a valve seat and an inflow orifice, a valve positioning member, and a flow limiting element that is disposed on the valve positioning member. The inflow orifice includes a step having a peripheral annular edge, and the flow limiting element is disposed on the valve positioning member in such a way that when the valve is opened, a flow area between the annular edge and the flow limiting element is reduced from a first flow area to a second flow area.

Injection valve having a flow limiter

A fuel injector has a valve needle that has a maximum diameter at a flow-off edge, and a valve seat acting together with the valve needle using a sealing seat, the valve seat widening, starting from the sealing seat up to a discharge edge, and the flow-off edge of the valve needle being offset backwards, in relation to the flow direction, with respect to the discharge edge of the valve seat, when the fuel injector is closed. The flow-off edge of the valve needle is offset backwards with respect to the discharge edge of the valve seat in a predetermined range of 2 micrometers to 20 micrometers, in the direction of a longitudinal valve axis.

Fuel injector

A method for operating an internal combustion engine in which a valve needle of a fuel injector is adjusted from a closing position via an intermediate position to an opening position and back again. The adjustment is carried out with the aid of a piezoelectric actuator to which a trigger signal is applied. To reduce the contamination danger of the fuel injector and to keep wear of the valve needle low, the trigger signal for triggering the piezoelectric actuator has a greater slope steepness during the transition of the valve needle from the closing position to the intermediate position than during the transition of the valve needle from the intermediate position to the opening position.

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Freiberg, Germany

Marco Vorbach