Fuel injection system for diesel engine

Patent · Tue Feb 03 04:00:00 EST 1987

OSTI ID:6875422

Nakamura, S; Matsuoka, T; Yamauchi, H; Sahara, M

This patent describes a fuel injection system for a diesel engine comprising a pintle type fuel injection nozzle and fuel supply means for feeding pressurized fuel to the fuel injection nozzle. The fuel injection nozzle has a valve needle slidable back and forth in the axial direction thereof between a vale closure position in which a front end portion thereof is inserted into a spray hole and a maximum lift position in which the distance between the front end portion and the spray hole is maximum. It also has a central plunger member which is slidable in the axial direction of the valve needle and provided with a front end face, opposed to a rear end face of the valve needle, and a rear end face adapted to receive the pressure of the the pressurized fuel fed to the fuel injection nozzle from the fuel supply means. The valve needle is adapted to be lifted by a predetermined fuel pressure to a pre-lift position where the rear end face of the valve needle abuts against the front end face of the plunger member so that further lift of the valve needle is resisted by the fuel pressure acting on the rear end face of the plunger member, thereby changing the valve opening pressure stepwise with change in the amount of lift of the valve needle. The improvement described here comprises pre-lift change means for changing the amount of the pre-lift of the valve needle and including fuel drain passages provided in a wall of a cylindrical space formed in a valve body and being spaced from each other in the direction of movement of the valve needle.

• Assignee: Mazda Motor Corp., Hiroshima
• Patent Number(s): US 4640252
• OSTI ID: 6875422
• Country of Publication: United States
• Language: English

Related Subjects

33 ADVANCED PROPULSION SYSTEMS
330102* -- Internal Combustion Engines-- Diesel
AUTOMOTIVE FUELS
CLOSURES
CONTROL EQUIPMENT
DIESEL ENGINES
DRAINAGE
ENGINES
EQUIPMENT
FLOW REGULATORS
FUEL INJECTION SYSTEMS
FUEL SYSTEMS
FUELS
HEAT ENGINES
INTERNAL COMBUSTION ENGINES
NOZZLES
POSITIONING
PRESSURE EFFECTS
PRESSURIZING
VALVES