Timing mechanism for a fuel supply system
AssigneeCummins Engine Company, Inc.
InventorJulius P. Perr
Life of this patent
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Abstract
This disclosure deals with a mechanism for adjusting the timing of initiation of injection by a fuel injector of an internal combustion engine. The mechanism includes a piston connected to be moved by a drive for the injector, and another piston which is connected to move the plunger of the injector. A timing fluid supply is provided for feeding a timing fluid into a timing chamber formed between the two pistons under selected operating conditions, the timing fluid forming a hydraulic link between the two pistons. The mechanism further includes pressure relief means for releasing a portion of the timing fluid after the termination of injection, the relief means comprising a pressure responsive mechanism.
Claims19
A system for controlling the timing of initiation of injection of a fuel injector of an internal combustion engine, the injector including a movable plunger which is alternately movable in an injection stroke and in a retraction stroke and is operable to inject fuel during the injection stroke, the engine further including movable drive means for moving said plunger, said timing control system comprising housing means having an opening therein, first and second members movably mounted in said opening, said housing means and said members forming a timing chamber therebetween, one of said members being connected to said drive means and the other of said members being connected to said plunger, a timing fluid supply hydraulically connected to said chamber for selectively feeding a timing fluid to said chamber, said timing fluid supply including means for controlling the flow of a timing fluid into said chamber, a quantity of said timing fluid present in said chamber forming a hydraulic link between said members, and pressure release means hydraulically connected to said chamber for releasing any timing fluid therein when the timing fluid pressure in said chamber reaches a predetermined pressure level during injection.
Apparatus for varying the timing of injection of a fuel injector for an internal combustion engine, the injector including a movable plunger which is movable in an injection stroke and in a retraction stroke and is operable to inject fuel during the injection stroke, and the engine further including drive means for moving the plunger, comprising a housing having a bore formed therein, a first piston movable in said bore and connected to be moved by said drive means, a second piston in said bore and connected to move with said plunger, means for metering a volume of a timing fluid into said bore between said first and second pistons, said timing fluid volume forming a variable length hydraulic link between said first and second pistons, and pressure responsive means connected to said bore for releasing at least a portion of said timing fluid volume when the pressure thereon reaches a predetermined level during said injection stroke.
Variable timing apparatus for an engine including drive means and a member to be driven by said drive means, comprising a housing having a bore formed therein, a first piston movable in said bore and connected to be moved by said drive means, a second piston movable in said bore and connected to move said member, means for metering a volume of timing fluid into said bore between said first and second pistons to form a variable length hydraulic link, and preloaded pressure responsive means connected to said bore for releasing a portion of said volume at pressures above a predetermined level.
A fuel supply system for an internal combustion engine, comprising an injector including a movable plunger which is movable in an injection stroke and in a retraction stroke and is operable to inject fuel during the injection stroke, drive means for moving the plunger, and variable timing means comprising a housing having a bore formed therein, a first piston movable in said bore and connected to be moved by said drive means, a second piston in said bore and connected to move with said plunger, means for metering a volume of a timing fluid into said bore between said first and second pistons, said timing fluid volume forming a variable length hydraulic link between said first and second pistons, and pressure responsive means connected to said bore for releasing at least a portion of said timing fluid volume when the pressure thereon reaches a predetermined level during said injection stroke.
Dependencies are inferred from the claim text.