US 5,178,110 AGranted

Fuel injection device for internal combustion engines

AssigneeRobert Bosch GmbH

InventorsFranz Guggenbichler, Jaroslaw Hlousek

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Abstract

A fuel injection device for injection internal combustion engines comprising a main injection plunger and a preinjection plunger, which is arranged coaxially with the latter and separated from the latter, and has a smaller diameter. The preinjection plunger is driven non-positively by the main injection plunger to make stroke movements against the force of at least one spring, which holds the preinjection plunger to bear against the main injection plunger. During the main injection, the working chamber of the preinjection plunger is connected to the working chamber of the main injection plunger, so that the preinjection plunger adds an injection portion to the main injection amount after termination of the preinjection and the spray interval, and the fuel pressure occurring in the working chamber of the preinjection plunger supports the action of the spring.

Claims24

Dependent claims

A fuel injection device for internal combustion engines, comprising at least one main injection plunger (4;

28) delimiting a first working chamber and at least one preinjection plunger (1;
20;
24) delimiting a second working chamber, said main injection plunger is axially aligned with said preinjection plunger (1;
20;
24), and said preinjection plunger is driven by said main injection plunger to make axial stroke movements, said preinjection plunger has a smaller diameter than said main injection plunger, said main injection plunger (4;
28) being rotatable and fitted with an inclined-edge (6), and the preinjection plunger (1;
20;
24) being held in contact with the main injection plunger (4;
28) by the force of at least one spring (5), a first injection nozzle (10) being provided for a main injection of fuel out of said first working chamber and at least one second injection nozzle (16) being provided for a preinjection of fuel out of said second working chamber, resulting from a joint axial movement of said main injection plunger and said preinjection plunger, and said second working chamber being connected to said first working chamber after the preinjection plunger having completed its stroke executing said preinjection of fuel.

6 more elements

Dependencies are inferred from the claim text.