Robert Boschgmbh

Josef Guntert

Walter Hafele

Johann Warga

Eberhard Hofmann

Helmut Tschoke

Max Straubel

Reinhard Schwartz

Manfred Kramer

Karl Reiff

Helmut Pfeifle

Fuel injection pump for internal combustion engines

A fuel injection pump for internal combustion engines having at least one pump element comprising a housing, a cylinder liner in the housing, a pump piston operative in the cylinder liner, a recess in the cylinder liner having a radial entrance, for a control slide which controls injection onset during axial displacement on the pump piston. In the vicinity of the entrance to the recess which discharges into the pump work chamber, an apron is disposed on the control slide or on the cylinder liner, in order to cover a portion of a radial three-dimensional gap present between the control slide and the cylinder liner. By this means, the diverted fuel stream that is reflected by the side walls can be interrupted and reflected at least one additional time, so as thereby to reduce its kinetic energy.

A fuel injection pump for internal combustion engines having control slides that are both axially displaceable and rotatable on the pump piston via a governor rod for controlling the injection quantity and the injection onset. A slit hub is releasably clamped on the governor rod with a driver arm, the hub being arranged to engage the control slide between two working faces and the hub has a driver recess for the rotational adjustment of the control slide. The driver recess is engaged by a tang joined with the control slide.

A fuel injection pump for internal combustion engines is proposed, in which for normal engine operation the control of the injection quantity and of the beginning and end of supply for injection is effected by means of a control slide which is axially displaceable on the pump piston and in which a radial bore (connecting conduit) controlled by the pump piston is present in the pump cylinder, with which radial bore the pump work chamber can be made to communicate with the suction chamber of the pump. The latest end of supply for the injection is determined in that after a predetermined stroke of the pump piston a relief conduit is arranged to coincide with the radial bore and thereby relieve the pump work chamber. Because the radial bore is only blocked after a pre-stroke has been executed by the pump piston the earliest supply onset also can be controlled with this bore as well.

A fuel injection pump for internal combustion engines having in-line pumping elements, having pump pistons on which control slides are axially displaceable, in particular for adjusting the injection onset; in a relatively greatly displaced position, these control slides being arranged to interrupt the injection. The control slides are moved by first and second governor rods, each part of which carries one group of driver members of the control slides, and both governor rods are rotatable relative to one another. As a result, it is possible for normal operation to be controlled by the one governor rod, while at the same time an appropriate number of engine cylinders is shut off by the other governor rod, in that the associated control slides are displaced into respective corresponding positions.

A fuel injection pump for internal combustion engines, in which at least during normal engine operation the injection quantity is effected by controlling a fuel quantity control conduit which is provided in the pump piston in communication with the pump work chamber, via a control slide that is displaceable on the pump piston in cooperation with fuel quantity control openings, the axial position of the control slide determining the onset and end of supply. The earliest possible supply onset is further determined by a supply onset control opening disposed in the pump piston, which opening is sealed by entering into the cylinder liner after a pre-determined stroke extent has been traversed. Subsequent to this entry, an injection pressure can build up in the pump work chamber.

A fuel injection pump is proposed for internal combustion engines having a control slide displaceable on the pump piston. The control slide cooperates with an oblique groove on a pump piston. The oblique groove is arranged to communicate via a conduit with a pump work chamber. The pump piston is rotatable and has a longitudinal groove of predetermined length on its jacket surface, which groove is adapted to communicate with the oblique groove and with its end remote from the pump work chamber determines the supply onset of the pump by plunging into the control slide.

The fuel injection quantity of a fuel injection apparatus provided with a fuel injection pump is electrically regulated by means of the opening duration of a metering valve. Additionally, a shift in the instant of supply onset controlled in accordance with operating characteristics is attained by means of a change in the return-flow fuel quantity, which is diverted into a refill reservoir and then refilled completely into the pump work chamber by the beginning of the next subsequent injection stroke. Serving as the sole connection between the refill reservoir and a pump work chamber is an overflow conduit, which is opened by two control locations on the pump piston at the end of a supply and shortly prior to the bottom dead center. Both the pump cylinder with the pressure valve and the refill reservoir and the metering valve are inserted in a leak-fuel-proof manner in a cylinder head of the pump housing, which is embodied in two parts. The decreased idle volume, the reduction of possible leakage points, and the complete refilling of the return-flow fuel quantity assure that the fuel injection quantity is determined unequivocally by the opening duration of the metering valves.

Fuel injection apparatus for internal combustion engines

An apparatus is proposed for the open-loop control of the composition of the operating mixture to be introduced into the combustion chambers of an internal combustion engine. In this apparatus, the dispensing of the aspirated air quantity is effected by means of an aspirated air throttle device, whose displacement complementarily adjusts the cross section of an exhaust gas recirculation line which discharges into the intake system downstream from this throttle device. The opening of the aspirated air throttle device in order to increase the quantity of aspirated air is effected by means of a control pressure delivered to a servomotor, counter to the force of a restoring spring. The control pressure is obtained from the comparison of the actual quantity of aspirated air with the fuel injection quantity. The initial pressure for establishing the control pressure is the supply pressure of a supply pump supplying the fuel metering device. In order to prevent the throttle device for aspirated air from being moved into the closed position during starting of the engine, an additional adjusting device, also actuated by fuel supply pressure, is provided. When supply pressure is absent, this adjusting device moves the aspirated air throttle device into the opening direction counter to the restoring force. At the same time, the outlet opening of the exhaust recirculation line is closed as a result.

Growing community of inventors

Gerlingen, Germany

Josef Guntert