Fuel Injector with Boosted Needle Closure
AssigneeSturman Digital Systems, LLC
InventorOded Eddie Sturman
Life of this patent
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Abstract
Fuel injectors with boosted needle control providing controlled and rapid needle closure. Boost and drive pistons are provided for hydraulic actuation to controllably close the needle, with the boost piston reaching a mechanical stop before the needle reaches the closed position, with the drive piston alone providing adequate hydraulic force to hold the needle closed. In a preferred embodiment, fuel from the intensifier is coupled to the top of the boost and drive pistons to close the needle, and controllably coupled to the bottom of the boost and drive pistons to allow pressure in the needle chamber to open the needle. Apparatus for control of fuel pressure to the bottom of the boost and drive pistons is disclosed.
Claims8
A method of operating an intensifier type fuel injector with direct needle control comprising:
- providing a boost piston and a drive piston, each disposed to controllably force the needle toward a needle closed position in response to hydraulic forces thereon, the boost piston including a stop to stop the motion of the boost piston before the needle reaches the closed position;
- when the needle is to be closed, unbalancing the hydraulic forces on the boost piston and drive piston to controllably force the needle toward the needle closed position, the area of the drive piston being adequate to maintain the needle closed against the needle opening force of fuel at the intensified pressure around the needle;
- when the needle is to be opened for fuel injection, equalizing the hydraulic forces of the boost and drive pistons to allow the needle to open.
8-14. (canceled)
Dependencies are inferred from the claim text.