Robert Boschgmbh

Karl Rapp

Karsten Hummel

Hansjoerg Frey

Ernst Ritter

Werner Faupel

Gunter Kampichler

Werner Schmid

Hans Brett

Alexander Tyrolt

Hans-Joachim Peters

Gabriel Stabentheiner

Alex Tyrolt

A fuel injection pump for internal combustion engines in which to control the fuel injection quantities with the internal combustion engine cold, a first control edge is provided. For controlling the start of fuel injection with the internal combustion engine hot, a second control edge and a third control edge are provided. Assigned to respective control edges are provided a first and second oblique control edge, by means of which an effective pump piston feed stroke is controlled according to the rotary position of the pump piston. To switch off the internal combustion engine, in the region of transition from the first control edge to the second control edge the assignment of this second control edge to the second oblique control edge is provided in such a way that injection ceases on account of an overlap with a control port. This measure is assisted by an additional longitudinal groove which, in this rotary position, is in overlap with an additional control port, this additional longitudinal groove being the extension of a longitudinal groove, via which a pump working space is relieved during the operation of the internal combustion engine and after a reopening of the control ports by the oblique control edges.

Fuel-injection pump for internal-combustion engines

A fuel injection pump for internal combustion engines, having a pump piston that is axially guided in a cylinder bushing which defines a pump work chamber there and is moved axially by a cam drive counter to the force of a restoring spring. The cam drive comprises a roller tappet connected to the pump piston whose roller rolls off on a cam of a camshaft driven by the internal combustion engine to be supplied. In the process, the roller is connected to the cylindrical part of the roller tappet by means of a roller pin disposed vertically to the axis of the roller tappet. This roller pin is axially secured by means of the contact of its axial ends to the wall of a bore that guides the roller tappet, for which purpose the transition area between the face ends, which extend vertically to the axis of the roller pin, and the circumferential area of the roller pin is part of a circular ring. The radius of the circular ring cross-section is adapted to the diameter of the wall of the roller tappet guide.

Fuel injection pump for internal combustion engines

A fuel injection pump for internal combustion engines having in-line cylinder bushes, in each of which a pump piston defining a pump work chamber is guided, the piston being rotatable by a governor rod for the sake of fuel supply quantity regulation. Mounted on the pump housing is an adjusting device, in which an adjusting piston is guided axially parallel with the governor rod; the adjusting piston has a radial pin, which protrudes through a slit in the wall of the adjusting device and pump housing into an oblong slot of the governor rod, thus limiting the adjusting motion of the rod in certain operating ranges. The position of the adjusting piston determines the maximum governing travel of the governor rod in the full-load direction upon engine starting. The adjusting piston is variable via an adjustable stop acting upon one face end thereof and is also variable as a function of temperature via a temperature-dependent spring element disposed on its circumference. In addition, with its face end, the adjusting piston defines a pressure chamber, by way of which the adjusting piston can be adjusted pneumatically in the direction of a zero supply quantity; via two stops of the oblong slot, the adjusting piston moves the control rod with it in the process and in this way interrupts the fuel delivery.

A fuel injection pump for internal combustion engines with a plurality of pump elements in which the fuel injection quantity is varied via a governor rod, which is supported in a U-shaped guide rail; according to the invention, this guide rail is loaded in its middle region by at least one spring element, in order to prevent transverse vibration of the governor rod.

A control device including a reversing valve, disposed in fuel lines into which a feed pump is introduced between a fuel supply tank and a suction chamber of a fuel injection pump, by means of which valve, to turn off an internal combustion engine operated with the fuel injection pump, the line connections are variable in such a way that the suction chamber communicates with the intake side of the feed pump and the compression side of the feed pump communicates with the fuel supply tank. As its valve member, the reversing valve has a slide, which carries first and second double-seat-valve closing bodies that cooperate with corresponding valve seats. The first and second double-seat-valve closing bodies form sealing elements which are detachably buttoned onto the slide that are made of an elastically deformable material. The sealing elements are provided with elastically deformable sealing lips pointing to the valve seats, so that oppositely disposed valve seats of each seat are reliably sealed off even if there are dimensional variations from manufacturing tolerances.

Control device for turning off an internal combustion engine

In a fuel injection pump for internal combustion engines, a leakage connection is provided for varying the fuel supply quantity and the supply onset in accordance with rpm. The leakage connection, in a pump piston executing the stroke movement, is effective only at the beginning of the supply stroke of the pump piston and becomes gradually less effective in stages in the middle rpm range. The leakage connection has an outer groove in the pump piston, a blind bore discharging in the piston end face, and at least one throttle bore connecting the blind bore with the bore bottom of the outer groove. The outer groove extends over only a portion of the circumference of the pump piston and parallel to the piston end face at a very small distance therefrom.

A fuel injection pump, embodied as a series pump, has a governor rod for rotating a pump piston provided with an oblique control groove. The pump piston further has at least one longitudinal groove, by means of which upon congruence with a fill and relief opening of the pump work chamber, a zero fuel supply can be established. With electrically controlled actuation of the governor rod, the appropriate adjustment of the end stops of the governor rod or the appropriate embodiment of the pump piston assures that the opening comes into congruence with a longitudinal groove adjoining the full-load working zone of the pump piston before the end stop of the governor rod is reached.

An edge controlled fuel injection pump for internal combustion engines, whose axially and rotationally movable pump piston, guided within the pump cylinder, has an improved leakage oil return system, which avoids piston wear and increased oil leakage even under very high injection pressures and relatively short piston strokes. The pump piston has an annular leakage oil collecting groove next to, but separate from, the recess that serves to end the fuel delivery, and a plurality of narrow leakage oil return grooves, which are formed in the outer surface of the piston diametrically opposite the recess and are connected with the collecting groove. Of these leakage oil return grooves, at least one is always connected with a leakage oil bore in the pump cylinder to a chamber of low pressure in the pump during the useful stroke of the piston.

Growing community of inventors

Stuttgart, Germany

Karl Rapp