Robert Boschgmbh

Helmut Giess

Dietrich Trachte

A fuel injection nozzle for internal combustion engines is proposed, which includes a valve needle stressed by a closing spring and a damping device to partially damp the opening movement of the valve needle. The damping is effected in accordance with the stroke frequency, the stroke length of the valve needle, or both, or the quantity of fuel throughput per injection cycle, and the damping effect is preferably variable automatically by shifting the time of the onset of damping relative to the onset of injection. As a result, an adaptation of the damping effect to the operating state of the engine at a particular time can be attained which substantially meets the ideal parameters for such damping.

Fuel injection nozzle for internal combustion engines

A fuel injection nozzle for internal combustion engines, having an outwardly opening valve needle, which is connected with a piston upon which a damping cap is placed, which is supported on a shoulder integral with the housing. In the damping cap, a damping chamber is formed, which communicates via a throttle conduit with the flow path of the fuel. The diameter of the piston is smaller than the cross section enclosed by the valve seat, as a result of which an annular shoulder is attained, on which the unthrottled fuel pressure acts upon the valve needle in the opening direction. This disposition has the advantage that at lower rpm and smaller fuel quantities, the valve needle can be effectively braked even up to relatively long needle strokes, without the injection duration becoming overly long at higher rpm.

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Aspach, Germany

Helmut Giess