Jeffrey A Graves

US Patent:

55666604, Oct 22, 1996

Filed:

Apr 13, 1995

Appl. No.:

8/420930

Inventors:

Fred A. Camplin - Peoria IL
Michael A. Flinn - East Peoria IL
Jeffrey D. Graves - Pontiac IL
Lianghe Zuo - Normal IL

Assignee:

Caterpillar Inc. - Peoria IL

International Classification:

F02M 3704
F02M 4702
F02B 300

US Classification:

123496

Abstract:

A multipiece fuel pump plunger assembly for controlling the fuel injection rate and delivery during the initial injection portion of a fuel injection cycle for an internal combustion engine. The injector includes a two piece plunger assembly including a plunger and a plunger sleeve. The plunger having a small predetermined diameter and being slidably positioned within a plunger sleeve having a diameter greater than the diameter of the plunger. The multipiece plunger is advantageous because it allows for shaping of the rate of fuel injected into the combustion process thereby reducing the excess fuel flow in the early portion of the injection cycle. Elimination of the excess fuel flow results in lower oxides of nitrogen and particulate exhaust emission levels and less engine noise.