Fuel injection apparatus for internal combustion engines, particularly diesel engines

A fuel injection apparatus for an internal combustion engine, and in particular for a Diesel engine, comprising:

• a fuel injection pump including means defining a pump cylinder, and a pump piston guided within the pump cylinder;
• a drive apparatus including a push rod;
• a cam shaft;
• a drive cam mounted for rotation on the cam shaft, said drive cam mechanically driving the pump piston through the push rod of the drive apparatus;
• an injection nozzle connected to the pump, said nozzle opening in response to an injection pressure which is rpm dependent;
• a control apparatus which operates in dependence on rpm;
• a correction apparatus;
• and
• an electronic controller connected to the control apparatus and to the correction apparatus, wherein:
• (i) the drive cam is formed to transmit a stroke motion to the pump piston during the supply of fuel to be injected;
• (ii) the onset of the fuel supply is corrected to a predetermined value dependent on operating characteristics of the engine, thereby compensating for an undesirable onset of the fuel supply effected by the control apparatus;
• (iii) the control apparatus and the correction apparatus are controlled by the electronic controller;
• and
• (iv) the stroke motion transmitted by the drive cam is effected by the apparatus in such a manner that the piston speed, which otherwise varies in proporation to engine speed, is corrected so that it is adaptable to a predetermined speed variation, thereby compensating for the rpm-dependent injection pressure variations, due to the variations in piston speed.

A fuel injection apparatus for an internal combustion engine, and in particular for a Diesel engine, comprising:

• a fuel injection pump including:
• means defining a pump cylinder;
• a two part piston consisting of a supply piston and a diverting piston;
• a fluid filled equalizing chamber enclosed between the two pistons, said equalizing chamber serving as a hydraulic push rod;
• an obliquely disposed control edge on the supply piston;
• a control aperture formed in the wall of the means defining the pump cylinder;
• and a pump work chamber within which an apportionment quantity of fuel is prestored;
• a drive cam for mechanically driving the supply piston, said drive cam defining two effective areas on its surface;
• and
• a setting device for rotating the supply piston, said setting device serving as an rpm-dependent control apparatus, wherein:
• (i) the equalizing chamber is blocked at the onset of the fuel supply by the control edge on the supply piston cooperating with the control aperture, is closed during the supply stroke, and relieved by the diverting piston in order to terminate the supply stroke;
• and
• (ii) the effective areas on the drive cam are controllable by the setting device in such a manner that the specific stroke speed effective during fuel supply, when the rpm is varying, remains substantially constant.

A fuel injection apparatus for an internal combustion engine, and in particular for a Diesel engine, comprising:

• a fuel injection pump including:
• means defining a pump cylinder;
• a two part pump piston consisting of a supply piston and a diverting piston;
• a fluid filled equalizing chamber enclosed between the two pistons, said equalizing chamber serving as a hydraulic push rod;
• an obliquely disposed control edge on the supply piston;
• a control aperture formed in the wall of the means defining the pump cylinder;
• and a pump work chamber within which an apportionment quantity of fuel is prestored;
• a drive cam for mechanically driving the supply piston, said drive cam defining two effective areas on its surface;
• and
• setting device for rotating the supply piston, said setting device serving as an rpm-dependent control apparatus, wherein:
• (i) the equalizing chamber is blocked at the onset of the fuel supply by the control edge on the supply piston cooperating with the control aperture, is closed during the supply stroke, and relieved by the diverting piston in order to terminate the supply stroke;
• and
• (ii) the effective areas on the drive cam are controllable by the setting device in such a manner that the specific stroke speed effective during fuel supply, when the rpm is varying, is adaptable to a predetermined speed variation.