Electronically-controlled fuel injector
AssigneeCaterpillar Inc.
InventorsGlen F. Forck, L. Glenn Waterfield
Life of this patent
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Abstract
An electronically-controlled fuel injector includes a pressurized fluid chamber that communicates high pressure fluid to first and second pressure control chambers. A direct-operated check moves between closed and open positions in response to a difference in fluid pressure in the first and second pressure control chambers. A first thermally pre-stressed bender actuator is used to operate a control valve that controls fluid communication between the fluid chamber and a fluid source. A second thermally pre-stressed bender actuator is used to operate a control valve that controls the fluid pressure in the first pressure control chamber to effectively control opening and closing of the check during portions of an injection sequence.
Claims17
A fuel injector comprising:
- an injector housing;
- a spill control valve member at least partially positioned in said injector housing;
- a needle control valve member at least partially positioned in said injector housing;
- a first electroactive bender actuator operably coupled to move said spill control valve member;
- and
- a second electroactive bender actuator operably coupled to move said needle control valve member.
A method of injecting fuel, comprising the steps of:
- closing a spill valve at least in part by changing a voltage applied to a first electroactive bender actuator;
- and
- opening a nozzle outlet at least in part by changing a voltage applied to a second electroactive bender actuator.
The method of claim 16 including a step of closing the nozzle outlet at least in part by exposing a closing hydraulic surface of a needle valve to high pressure fuel.
Dependencies are inferred from the claim text.