Electromagnetic unit fuel injector

Patent · Mon Feb 24 23:00:00 EST 1986

OSTI ID:5852602

Deckard, J I

This patent describes an electromagnetic unit fuel injector of the type including a housing havine a pump cylinder therein; an externally actuated plunger reciprocable in the cylinder means to define therewith a pump chamber. The housing includes a valve body having a spray outlet at one end thereof for the discharge of fuel. An injection valve is movable in the valve body to control flow through the spray outlet. An inlet passage is in flow communication with the pump chamber and is connectable at its other end to a source of fuel. A pressure modulated servo chamber is in the housing. A spring means and a servo piston means operatively connected to the injection valve with the servo piston means being positioned so as to be acted on by the pressure of fuel in the servo chamber and a discharge passage in the housing connects the pump chamber to the spray outlet and to the servo chamber and has a throttle orifice controlling fuel flow to the servo chamber. The housing means further includes a drain passage means in flow communication at one end with the servo chamber and at its opposite end with a source of fuel at a predetermined pressure and a pressure sensitive control valve operatively positioned in the housing. A pull type solenoid is operatively supported in the housing means and a fuel passage means connectable is at one end to a source of fuel at a suitable supply pressure and at its other end being in operative flow communication with the pump chamber. The improvement wherein the control valve is in the form of a poppet valve and wherein the stepped bore includes an enlarged internal diameter portion next adjacent to the valve seat whereby the pressure of fuel in the annulus cavity can act against the head in a valve opening direction and wherein the force of the valve return spring is preselected so that the control valve is also operative as a pressure relief valve.

• Assignee: General Motors Corp., Detroit, MI
• Patent Number(s): US 4572433
• OSTI ID: 5852602
• Country of Publication: United States
• Language: English

Related Subjects

33 ADVANCED PROPULSION SYSTEMS
330100* -- Internal Combustion Engines
CONTROL
CONTROL EQUIPMENT
CYLINDERS
DESIGN
DRAINAGE
ELECTRIC COILS
ELECTRICAL EQUIPMENT
ELECTROMAGNETISM
ENGINES
EQUIPMENT
FLOW REGULATORS
FLUID FLOW
FUEL INJECTION SYSTEMS
FUEL SYSTEMS
HEAT ENGINES
INTERNAL COMBUSTION ENGINES
MAGNETISM
OPENINGS
ORIFICES
POSITIONING
PRESSURE CONTROL
PUMPS
RELIEF VALVES
SOLENOIDS
VALVES