摘要 |
In a combination which includes a fuel injection unit and a cylinder of a diesel engine provided with a cover, and formed with a fuel bore communicating with a suction chamber, a piston is reciprocally moving within the cylinder, and is provided with a slanted front and rear control edge for regulating the quantity of fuel. The cylinder and piston define piston- and cylinder-surfaces separated from each other by a very small clearance, and are movable relative to each other; an injection nozzle includes a spring-loaded needle, a common casing houses the piston and the cylinder, a securing flange is disposed between the fuel bore and an end of the cylinder facing the cover, a tensioning device stresses the securing flange against the cover, and the piston, during its stroke, passes over the fuel bore. The improvement includes a cylindrically offset recess formed within a region of the securing flange on the cylinder surface, and the front control edge of the piston is formed with a first step-like recess with respect to the piston-surface. Consequently any undesired pressure peaks are avoided within the cylinder, when the piston passes over the fuel bore, while the clearance is substantially maintained between the piston surface and the cylinder surface during the stroke of the piston.
|