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US 11,220,980 B2Granted
Fuel system having isolation valves between fuel injectors and common drain conduit
AssigneeCaterpillar Inc.
InventorsSiddharth Nair, Manjunath Bannur Nagaraja
Life of this patent
Estimating the term…
Abstract
A fuel system includes a plurality of fuel injectors connected to a common drain conduit, and a plurality of isolation valve assemblies each positioned fluidly between the common drain conduit and one of the plurality of fuel injectors. Each isolation valve assembly includes a valve member movable between a closed position to block an injection control valve assembly in the fuel injector from the common drain conduit, and an open position, and a biaser biasing the isolation valve member toward the closed position such that fuel injectors are isolated from fluid pressure pulses produced by nozzle check actuation to limit cross-talk among the fuel injectors.
Claims16
A fuel system comprising:
- a plurality of fuel injectors, each of the plurality of fuel injectors including an injection control valve assembly and a direct operated nozzle check, and having a high pressure nozzle supply passage, a first low pressure outlet, a second low pressure outlet, and a check control chamber formed therein;
- a common drain conduit fluidly connected to each of the plurality of fuel injectors to receive drained actuating fluid for each of the direct operated nozzle checks;
- a plurality of isolation valve assemblies and a plurality of drain lines, each of the plurality of isolation valve assemblies being positioned fluidly between the injection control valve assembly of one of the plurality of fuel injectors and one of the plurality of drain lines;
- the plurality of drain lines each forming one drain line connection to the common drain conduit for draining actuating fluid from the one of the plurality of isolation valve assemblies, and a total number of drain line connections in the fuel system for draining actuating fluid from the plurality of isolation valve assemblies to the common drain conduit is equal to a total number of the plurality of fuel injectors in the fuel system;
- each of the plurality of isolation valve assemblies including a first isolation valve member movable between a closed position blocking the injection control valve assembly in the respective one of the plurality of fuel injectors from the corresponding first low pressure outlet, and an open position, and a first spring biaser biasing the isolation valve member toward the closed position;
- each of the plurality of isolation valve assemblies includes a second isolation valve member movable between a closed position blocking the injection control valve assembly in the respective one of the plurality of fuel injectors from the corresponding second low pressure outlet, and an open position, and a second spring biaser biasing the second isolation valve member toward the closed position;
- and
- each of the plurality of isolation valve assemblies is resident in the respective one of the plurality of fuel injectors.
5 more elements
A fuel injector comprising:
- an injector body having a high pressure nozzle supply passage, a check control chamber, and a valve body having a first low pressure outlet and a second low pressure outlet formed therein;
- a direct operated nozzle check;
- an injection control valve assembly;
- and
- an isolation valve assembly including a first isolation valve member movable between a closed position fluidly isolating the injection control valve assembly from the first low pressure outlet, and an open position, a first spring biaser biasing the first isolation valve member toward the closed position, and a first snap ring supported in the valve body, and the first spring biaser is trapped between the first snap ring and the first isolation valve member;
- the isolation valve assembly further including a second isolation valve member movable between a closed position fluidly isolating the injection control valve assembly from the second low pressure outlet, and an open position, and a second spring biaser biasing the second isolation valve member toward the closed position, and a second snap ring supported in the valve body, and the second spring biaser is trapped between the second snap ring and the second isolation valve member;
- and
- each of the first isolation valve member and the second isolation valve member defining a longitudinal axis and including a valve head having an axial end surface in contact with the respective spring biaser, an underhead surface, and a valve stem extending from the underhead surface, and the underhead surface is in contact with the injector body at the respective closed position.
5 more elements
An isolation valve assembly for a fuel system comprising:
- a valve body positionable in a fuel injector, the valve body having formed therein a first low pressure outlet, a second low pressure outlet, and a drain path structured to fluidly connect to a check control chamber for an outlet check in the fuel injector;
- a plate supported in the valve body and including a valve seat positioned fluidly between the drain path and each of the first low pressure outlet and the second low pressure outlet;
- an injection control valve assembly including an injection control valve member movable between a closed control valve position blocking the valve seat, and an open control valve position;
- a first isolation valve member positioned fluidly between the injection control valve assembly and the first low pressure outlet and movable between an open isolation valve position and a closed isolation valve position, and the first isolation valve member having a valve head in fluid sealing contact with the valve body fluidly isolating the injection control valve assembly from the first low pressure outlet at the closed isolation valve position;
- a first spring biaser biasing the first isolation valve member toward the closed isolation valve position, such that movement of the first isolation valve member from the closed isolation valve position to the open isolation valve position in response to a pulse of fluid pressure through the valve seat is in opposition to a biasing force of the first spring biaser;
- a second isolation valve member positioned fluidly between the injection control valve assembly and the second low pressure outlet and movable between an open isolation valve position and a closed isolation valve position, and the second isolation valve member having a valve head in fluid sealing contact with the valve body fluidly isolating the injection control valve assembly from the second low pressure outlet at the closed isolation valve position;
- a second spring biaser biasing the second isolation valve member toward the closed isolation valve position, such that movement of the second isolation valve member from the closed isolation valve position to the open isolation valve position in response a pulse of fluid pressure through the valve seat is in opposition to a biasing force of the second spring biaser;
- and
- each of the first isolation valve member and the second isolation valve member defining a longitudinal axis and including upon the respective valve head an axial end surface in contact with the respective spring biaser, an underhead surface, and a valve stem extending from the underhead surface, and the underhead surface is in contact with the valve body at the respective closed isolation valve position.
6 more elements
Dependencies are inferred from the claim text.