US 4,571,161 AGranted

Pump/nozzle unit for fuel injection in internal combustion engines

AssigneeRobert Bosch GmbH

InventorsJean Leblanc, Jean Pigeroulet, Francois Rossignol

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Abstract

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 pump/nozzle unit for fuel injection in internal combustion engines comprising:

(a) a pump housing receiving a piston-type injection pump provided with an injection nozzle at one end thereof;
(b) a pump piston axially guided in a cylindrical bore in the pump housing said pump piston being rotatable by means of a regulating sleeve disposed coaxially therewith in order to vary an effective supply stroke and actuable via a drive tappet counter to force exerted by a tappet spring;
(c) a guide bushing secured on the pump housing and provided with a sleeve-like guide part for said drive tappet and an end face forming an axially positional securing means for the regulating sleeve;
(d) an extremity face being provided on the drive side on the pump housing;
(e) an actuation flange being provided on the pump housing at least indirectly engaged by securing means for securing the pump/nozzle unit to the engine;
(f) said guide bushing being provided with a bushing flange protruding radially outward beyond an outer diameter of the tappet spring, said bushing flange being provided with an end face resting on said extremity face on the drive side of the pump housing and extending into a region provided adjacent the extremity face for engagement by said securing means of the pump/nozzle unit;
(g) said bushing flange being secured on the pump housing by a holder means;
(h) said holder means for the guide bushing being arranged to pass through an oblong slot in the bushing flange of the guide bushing and be secured to a securing flange of the pump housing;
(i) said regulating sleeve being provided with a radially protruding control lever arm associated with a control lever arm regulating means;
(j) said guide bushing having a flange area in which is disposed a recess provided as a circular segmented ring in which a cutaway is provided allowing passage therethrough of said control lever arm, said recess being further provided with lateral limiting edges defining a maximum pivoting range for said control lever arm in at least one pivoting direction;
and
(k) said flange of said guide bushing provided with at least one oblong slot for receiving said holder means, said at least one oblong slot being arranged to allow said guide bushing to be slightly rotatable within a limited range of movement, whereby
adjustment of a fuel supply quantity provided by said pump/nozzle unit is faciliated.

10 more elements

Facts

Application

06/714,233Filed 21 Mar 1985

Priority

DE 341140728 Mar 1984

Granted

18 Feb 1986

Term ends

Not estimatedThe source records don’t support an estimate.

Classification5 codes

F02M 57/023
Characterised by the pump drive: mechanical
F02M 57/02
Fuel-injectors combined or associated with other devices: injectors structurally combined with fuel-injection pumps
F02M 59/28
Caused by movements of pistons relative to their cylinders: mechanisms therefor
F02M 61/14
Fuel-injectors not provided for in groups F02M39/00 - F02M57/00 or F02M67/00: arrangements of injectors with respect to engines; Mounting of injectors

Abstract

Claims9