Robert Boschgmbh

Wilhelm Vogel

Max Straubel

Karl Hofmann

Dietrich Trachte

Iwan Komaroff

Kurt Seifert

Paul Fussner

Hans-Jorg Vogtmann

Konrad Eckert

Hermann Eisele

Heinz Kuschmierz

Katsuoki Itoh

Klaus-Dieter Zimmermann

A fuel injection nozzle for internal combustion engines having a valve needle which enters an intermediate position in a retarded fashion and subsequently reaches its final position quickly. The valve needle is coupled in a positively-engaged manner with a supplementary body which as a result of its mass and/or hydraulically damps the movement of the valve needle over the course of a first stroke portion. At the end of this stroke portion, the supplementary body strikes a shoulder attached to the housing, whereupon the valve needle after the attainment of a notably higher fuel pressure, is separated from the supplementary body and translated quickly into its open position. In special cases, it is also possible for two supplementary bodies to be provided, which are uncoupled one after another from the valve needle and then again recoupled to the valve upon the closure of the valve. With an apparatus of this kind, the injection procedure can be adapted more freely than in the case of the known injection nozzles to a desired course.

Fuel injection nozzle for internal combustion engines

A fuel injection apparatus for internal combustion engines, in which the onset and end of injection are determined by a hydraulically actuated control slide. The injection pump of the apparatus, which is preferably combined with an injection nozzle to form a pump/nozzle unit, has a pump piston embodied as a differential piston, whose section having the larger diameter serves as an auxiliary pump piston and generates a control pressure (p.sub.S) actuating the control slide. During its compression stroke the control slide, in order to initiate the onset of injection, closes an overflow line leading out of the pump work chamber; and during its return stroke, which is effected by the pressure drop in the control line, the control slide relieves the overflow line in order to control the end of injection. The control pressure (p.sub.S) in the control line necessary for actuating the stroke movement of the control slide is controlled by the closure of this line by means of a control device and is built up during the compression stroke of the auxiliary pump piston.

Fuel injection apparatus for internal combustion engines, in particular

A fuel injection arrangement for an internal combustion engine, has a control device for receiving an electrical signal corresponding to a quantity of applied fuel, comparing an actual value with a nominal value of the supplied fuel quantity, and producing a correcting signal for fuel supply, and also has a measuring element for measuring the quantity of the supplied fuel and producing the responding electrical signal, wherein the measuring element includes a quartz pressure measuring diaphragm producing the electrical signal by a piezoelectric effect on quartz because of a differential pressure on the measuring diaphragm.

Fuel injection arrangement

To provide for coupling the injection needle of a Diesel injection valve with an inertia mass, and thereby provide for speed damping of the movement of the valve, the pressurized Diesel fuel is applied to a chamber (20,68) in the valve body (10,12,14), which slidably retains the needle valve element (18) at a location downstream of the inertia mass, the inertia mass subdividing the chamber into a spring or pressure chamber (20) and a damping chamber (68) forming a dead, or storage chamber for fuel, the inertia mass being slidable in the second chamber and the clearance between the inertia mass and the walls of the chamber forming a throttled connection duct so that, upon command to opening movement, the needle valve element will engage, after a short dead distance (v), the inertia mass (62) which must move against the flow resistance through the throttled connection upon shifting of fuel between the first and second chamber and thus damping the speed of operation of the valve element. The pressure differential at the two sides of the inertia mass will act on the entire cross-sectional area of the inertia mass, to provide high initial damping of the valve needle movement upon initiation of an opening stroke, while permitting a slim construction minimizing external diameter.

Fuel injection valve for an internal combustion engine

In the method according to the invention, the inlet pressure and the inlet cross section of the fuel pre-stored in the pump work chamber is constant, and it is solely the opening duration of an inlet valve which is electrically regulated. In addition, a shift in the instant of supply onset controlled in accordance with operating characteristics is attained by means of a variation in the return-flow fuel quantity. A shift in the instant of supply onset, which is undesired when there is a change in the quantity of fuel to be injected, is prevented by means of a simultaneously-effected correction of the return-flow fuel quantity. A fuel injection apparatus suitable for performing the method has, as the inlet valve, a magnetic valve which determines the quantity of fuel pre-stored in the pump work chamber. The rotary position of the pump piston is variable in order to shift or correct the instant of supply onset by means of an adjacent device actuated by an electromechanical adjustment element. An electric control device emitting the metering pulse and a control pulse is connected with a set-point transducer and an adjustment-path transducer of the adjustment device. The apparatus can be equipped with either a pump/nozzle or a normal piston injection pump supplying the injection nozzle via a pressure line, or with a distributor injection pump.

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Stuttgart, Germany

Wilhelm Vogel