Ambac Industries, Inc.

A-i-l Corporation

John B Cavanaugh

John A Kimberley

Robert A DiDomenico

Eric S Brisbon

Richard D Kraus

Jeffrey P DiCarlo

Rous S Karlson

A high pressure fuel injection system utilizes a pressure regulating or control valve to provide a high residual pressure within the injector between injections. Maintaining a high residual fuel pressure boosts the injection pressure to provide improved fuel atomization, with consequent reductions in particulate emissions and increased fuel efficiency. The pressure regulating valve, which may be located in the injector leak-off fuel conduits or in the high pressure line connecting the fuel injection pump with the injector, may be controlled in accordance with engine operating conditions to provide a variable injection pressure boost commensurate with engine requirements.

High pressure fuel injection system

The invention provides means for controlling the rate of fuel injection of an accumulator injector of the type employing a pressure amplifying piston assembly. In one form of the invention, the injection rate is controlled by restricting the pressure decay in the amplifier chamber. In another form of the invention, means are provided for delaying the full opening of the injector valve needle after an initial valve opening.

Rate control in accumulator type fuel injectors

An improved arrangement for mounting an injection barrel in the mounting bore of a fuel injection pump housing and maintaining the integrity of a fluid seal therebetween. A pumping chamber is defined in each injection barrel. Each injection barrel includes a pair of axially spaced annular seats in the external periphery thereof, preferably beyond the axially opposite ends of the pumping chamber. A respective annular seal is seated in each of the respective seats, and when uncompressed, projects radially beyond the barrel periphery. Each mounting bore includes a pair of chamfered surfaces formed at axially spaced locations, each chamfered surface having a respective diameter sufficiently small for compressively engaging a respective seal when the barrel is mounted. The included angle of each of the chamfered surfaces is relatively small to allow axial adjustment of the mounted position of the injection barrel. The diameter of the mounting bore between the surface of the pump housing and the axially innermost chamfered surface of the pair is always greater than the uncompressed diameter of the axially innermost seal to prevent shaving.

Mounting arrangement for injection barrel in housing of fuel injection

An improved fuel rack mounting arrangement, particularly for use in an in-line pump, is structured to reduce actuating forces. The fuel rack is supported by a pair of lever arms pivotally connected thereto at longitudinally spaced pivot axes. Each lever arm is also pivotally connected to the pump housing at separate pivot axes. The orientation and positioning of the various pivots are such as to afford longitudinal reciprocation of the rack in response to actuation of one of the levers about its pivot axis by which it is connected to the housing. The actuation may be provided by a stepper motor acting on an extension of the lever. Each lever may include an integral pivot pin and a locking mechanism for captured pivotal mounting of the rack.

Mounting arrangement for fuel rack in fuel injection pump

A fuel injection pump of the rotary distributor type having opposed fuel pumping pistons housed within a rotor and actuated by an internal ring cam. Fuel distribution, metering and timing control are effected through ports and slots associated with the rotor, the pump housing and a spill sleeve. The angular position of the cam is varied automatically in accordance with changes in engine speed as are the relative positions of certain ones of said ports and slots to provide an automatic advance of the fuel injection timing. The pump is particularly suited for electronic governing, electronic timing control and electronic control of rate of injection.

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West Springfield, MA, United States of America

John B Cavanaugh