Robert Boschgmbh

Jean Pigeroulet

Jean Leblanc

Francois Rossignol

Max Straubel

Helmut Pfeifle

Dominique Buisson

Ewald Eblen

Dietrich Trachte

Nikolaus Simon

Francois Henry

Helmut Rembold

Karl Hofmann

Helmut Laufer

Konrad Eckert

Nestor Rodriguez-Amaya

Detlev Potz

Hermann Eisele

Alfred Schmitt

Walter Egler

Anton Karle

Volker Holzgrefe

Wilhelm Christ

Pierre Lauvin

Werner Pape

Ewald Ziegler

Hannes Pflug

Hans-Joachim Siebert

Raymond Tissot

Friedrich Weiss

Rodriguez-Amaya

A fuel injection pump is proposed in which over a first portion of the supply stroke of the pump piston fuel for the main injection is pumped via a distributor line and a distributor groove into one at a time of a plurality of fuel injection lines. In a second, remaining portion of the pump piston supply stroke, on the same cam flank, fuel is then pre-stored in a reservoir, controlled by a first electrically controlled valve and a second electrically controlled valve and by one of a plurality of longitudinal control grooves, which fuel subsequently, before the beginning of the next main injection determined by the closure of the first electrically controlled valve, is pumped via a second distributor line into the next succeeding injection line.

Fuel injection pump

A fuel injection device having a pump piston which during the supply stroke pumps fuel from a pump work chamber into an injection line which leads to a fuel injection valve. Directly adjacent to the branching off of the injection line from the pump work chamber, at the diameter of the injection line, a valve seat is provided, at which the injection line then merges with a chamber into which a pressure valve closing member plunges. The valve closing member is tightly guided in a guide bore, loaded by a valve spring, and in the chamber has a pressure shoulder adjoining the sealing surface that cooperates with the valve seat. The rear side of the pressure valve closing member communicates with a continuously open relief line. Because of this construction, the pressure valve closing member operates as an equal-pressure valve and simultaneously as a deflecting piston as well, with the aid of which a pressure rise in the pump work chamber is built up in a retarded manner until such time as the pressure valve closing member comes to rest on a stop. A pressure rise of this type is particularly advantageous in connection with control of the injection phase by means of a magnetic valve subjected to the high pressure.

Fuel injection device

A fuel injection apparatus which the termination of the effective pump supply stroke is effected by exposing a relief conduit with the aid of a valve having for instance a control edge, whereupon a highly pressurized fuel flows out via the relief conduit and is directed into a pressure chamber defined by a rear face of a pressure valve closing member. The pressure valve closing member is located in a connection with a fuel injection line that leads from the pump work chamber to the fuel injection valve and is acted upon by a valve spring to effect closing of this injection line. The impact of fuel that reaches the pressure chamber via the releif conduit reinforces a fast closure of the pressure valve closing member at the end of injection, which leads to an abrupt termination of an injection cycle. In addition, or altenatively, the fuel injection valve closing member can also be acted upon by the impact of fuel diversion.

Fuel injection apparatus for internal combustion engines

The unit fuel injector has a pump piston driven at a constant stroke length, which pumps fuel at injection pressure to an injection nozzle as long as an electrically actuated overflow valve blocks the flow of the fuel flowing from the pump work chamber to a low-pressure chamber via an overflow conduit. The overflow valve is inserted between a first section which communicates continuously with the pump work chamber and a second section leading to the low-pressure chamber of the overflow conduit and is secured to a housing part laterally projecting from the pump housing. The first section of the overflow conduit comprises a connecting bore leading away from the pump work chamber, a control conduit controlled by the overflow valve, and a transverse conduit connecting these two. The transverse conduit extends from the housing side remote from the projecting housing part to the control conduit, crossing through the cylinder bore and in every stroke position of the pump piston is sealed off, without additional sealing means, by the jacket face of the pump piston. The unit fuel injector is particularly suitable for high-pressure injection in Diesel engines.

Electrically controlled unit fuel injector for fuel injection in diesel

The injection pump has a pump piston driven with a constant stroke which pumps fuel at injection pressure to an injection nozzle so long as an electrically actuated overflow valve blocks the flow of the fuel overflowing via an overflow conduit to a low-pressure chamber. The overflow valve is a needle valve, the valve needle of which, opening inward toward a pressure chamber that can be placed under injection pressure, by means of a conical closing surface radially defining a needle tip controls a valve seat that widens conically toward the pressure chamber. The cone angle of the closing surface is larger than the cone angle of the associated valve seat and the closing surface forms a sealing edge, the diameter of which is equal to or only slightly smaller than the guide diameter of the guide shank on the valve member. In a preferred embodiment, the needle tip of the valve member has an external contour on its end, adjacent to the closing surface, which directs the fuel flow and reinforces the opening movement. The injection pump is particularly suitable for high-pressure injection in Diesel engines, in order to attain an exact electrical control of the supply onset and supply quantity, if a reservoir chamber defined by a deflecting piston is connected to a high-pressure chamber that includes the pump work chamber.

Electrically controlled fuel injection pump for internal combustion

A pump/nozzle unit having a piston injection pump and an injection nozzle which includes a pump piston that is driven via a drive tappet and is rotatable via a regulating sleeve. The regulating sleeve is inserted into a recess on the end face of the pump housing and is axially secured in its installed state by means of a guide bushing. The guide bushing comprises a guide part for the drive tappet and a flange radially protruding beyond the outer diameter of the tappet spring, the flange being secured on the pump housing by a holder mechanism. The forces exerted upon the pump/nozzle unit during operation are absorbed by a securing arrangement. The drive assembly unit, including the drive tappet, tappet spring, guide bushing and pump piston, which is held together by a loss-preventing device, can be mounted outside the pump/nozzle unit and removed as a unit for purposes of mounting and inspecting the regulating sleeve, and even in the demounted or disassembled state of the pump/nozzle unit this drive assembly unit remains joined to the pump/nozzle unit by the holder mechanism.

Pump/nozzle unit for fuel injection in internal combustion engines

The pump/nozzle unit for a fuel injection system is disclosed which has a pump piston that is driven via a drive tappet and is rotatable by means of a regulating sleeve. The regulating sleeve, provided with a radially protruding control lever arm, is axially secured in its installed position by means of a guide bushing. The guide bushing includes a guide part for the drive tappet and a radially protruding flange, which is secured to the pump housing by at least one holder passing through an oblong slot on the flange of the guide bushing. A recess in the form of a circular segmented ring is cut out of the guide bushing for the passage therethrough of the control lever arm. By rotating the guide bushing within a range limited by the oblong slot a lateral limiting edge of the recess is adjustable into a position in which the pump piston, with the control lever arm resting on the limiting edge assumes a rotational position associated with a fixed supply quantity. As a result, no further additional or full-load stop device is necessary and mounting of the drive unit and pump assembly on the engine are facilitated.

A fuel injection pump for internal combustion engines in which by means of an obliquely extending control groove on the jacket face of a distributor, the end of injection can be varied by opening a relief conduit during the displacement of the distributor. The injection onset is made to follow this variable end of injection by providing that the stroke position of the pump pistons of the fuel injection pump is ascertained at the end of injection by a transducer, by means of which at the same time a metering duration of a magnetic valve that has already been opened at the time of the end of the injection stroke is controlled. In this manner, with a radial piston pump so embodied, the opportunity is afforded of accurately adjusting the quantity of fuel to be metered by means of a magnetic valve, even with variable injection times. All that needs to be done is that the magnetic valve be closed exactly and rapidly at the end of metering, while an error in opening on the part of the magnetic valve does not occur. In this manner, a very precise metering of the fuel to be injected is attained with simple means.

A fuel injection pump is proposed which has a distributor in which both the injection quantity and the onset of injection are variable. The distributor is axially displaced via electric servomotors and is rotated relative to the drive shaft.

A fuel injection apparatus for internal combustion engines is proposed (FIG. 1), in which the onset and end of injection are determined by a hydraulically actuated control slide. The injection pumps of the apparatus, which are preferably combined with an injection nozzle to make a pump/nozzle unit, having a central magnetic valve assembly comprising two magnetic valves switched hydraulically in parallel, which valve assembly is inserted in a connection between a control pressure line, which can be placed under control pressure (P.sub.S) from a source of control fuel, and a low-pressure line which is under supply pressure (P.sub.V). In order to initiate the onset of injection, the control slide is placed under control pressure (P.sub.S) by the valve assembly via a distributor apparatus and closes an overflow channel leading out of the pump work chamber. In order to control the end of the injection, the control slide, during its return stroke, relieves this overflow channel toward a low-pressure line. The control pressure (P.sub.S) in the control pressure line required for actuation of the stroke movement of the control slide is built up by means of the valve assembly as a result of blocking the outflow from this line.

Fuel injection apparatus for internal combustion engines, in particular

A fuel injection apparatus for internal combustion engines is proposed in which the onset and end of injection are determined by a hydraulically actuated control slide. The injection pumps of the apparatus, which are preferably combined with an injection nozzle to make a pump/nozzle unit have a central control pressure pump supplied with fuel by a supply pump. The control pressure pump creates a control pressure (p.sub.S) which is a multiple increase in comparison to the supply pressure (p.sub.V) of the supply pump and actuates the control slide. Each control slide is placed under control pressure (p.sub.S) to initiate the onset of injection via a control line which is separated from the filling lines of the injection pump and closes an overflow channel which leads away from the pump work chamber. At the end of injection the control slide again relieves this overflow channel to a supply line during its return stroke.

A fuel injection apparatus (FIG. 1) for internal combustion engines is proposed, in which the onset and end of injection are determined by means of a hydraulically actuated control slide. The injection pumps of the apparatus, preferably combined with an injection nozzle to make a pump/nozzle unit, have a central control fuel source represented by a supply pump and a first pressure limitation valve, which generates a control pressure (p.sub.S) actuating the control slide which is several times greater than the supply pressure (p.sub.V) determined by a second pressure limitation valve. In order to initiate the onset of injection, the control slide is placed under control pressure (p.sub.S) by a valve assembly via a distributor apparatus and closes an overflow channel leading out of the pump work chamber. In order to control the end of injection, the control slide during its return stroke again relieves this overflow channel toward a low-pressure line. The control pressure (p.sub.S) in the control pressure line required for actuating the stroke movement of the control slide is established by means of blocking the outflow out of this line by means of the valve assembly.

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Villeurbanne, France

Jean Pigeroulet