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US 10,519,916 B1Granted
Flexible rate shape common rail fuel system and fuel injector for same
AssigneeCaterpillar Inc.
InventorsDana R. Coldren, Sana Mahmood, Stephen R. Lewis
Life of this patent
Estimating the term…
Abstract
A fuel system for an internal combustion engine includes a common rail and a plurality of fuel injectors connected to the common rail and each including an outlet check, an injection control valve, and an injection rate controller. The injection rate controller varies a flow area to a nozzle of the fuel injector such that a pressure drop through the fuel injector is varied to provide injection rate shaping.
Claims20
A fuel system for an internal combustion engine comprising:
- a fuel supply;
- a common rail;
- a fuel pressurization pump structured to pressurize a fuel for supplying to the common rail;
- and
- a plurality of fuel injectors each having formed therein a high pressure inlet fluidly connected to the common rail, a nozzle chamber fluidly connected to the high pressure inlet by way of a nozzle passage, a control chamber fluidly connected to the high pressure inlet, a plurality of spray orifices, and a low pressure outlet;
- each of the plurality of fuel injectors further including an outlet check movable to open and close the plurality of spray orifices to the nozzle chamber and having a closing hydraulic surface exposed to a fluid pressure of the control chamber, and an injection control valve movable to open and close the control chamber to the low pressure outlet;
- each of the plurality of fuel injectors further including an injection rate controller exposed to a flow of fuel through the nozzle passage, and adjustable between a rate limiting configuration, and a second configuration;
- and
- a flow area of the nozzle passage is limited by the injection rate controller to a relatively greater extent at the rate limiting configuration, and the flow area is limited to a relatively lesser extent at the second configuration.
6 more elements
A fuel injector comprising:
- an injector body having formed therein a high pressure inlet structured to fluidly connect to a common rail, a nozzle chamber fluidly connected to the high pressure inlet, a control chamber fluidly connected to the high pressure inlet, a plurality of spray orifices, and a low pressure outlet;
- the injector body further having formed therein a nozzle passage that extends between the high pressure inlet and the nozzle chamber;
- an outlet check movable to open and close the plurality of spray orifices to the nozzle chamber to inject a fuel supplied from the common rail into an engine cylinder and having a closing hydraulic surface exposed to a fluid pressure of the control chamber, and an injection control valve movable to open and close the control chamber to the low pressure outlet;
- each of the plurality of fuel injectors further including an injection rate controller exposed to a flow of fuel through the nozzle passage;
- the injection rate controller is in a rate limiting configuration where a flow area of the nozzle passage is limited by the injection rate controller to a relatively greater extent, and adjustable to a second configuration where the flow area of the nozzle passage is limited by the injection rate controller to a relatively lesser extent to reduce a pressure drop from the high pressure inlet to the nozzle chamber during the injection of fuel.
2 more elements
A method of operating a pressurized fuel injection system comprising:
- conveying a pressurized fuel from a common rail into a fuel injector;
- opening an outlet check in the fuel injector to start an injection of the pressurized fuel from the fuel injector into a cylinder in an internal combustion engine;
- adjusting an injection rate controller within the fuel injector between a rate limiting configuration and a second configuration after the start of the injection of the pressurized fuel to vary a pressure drop through a nozzle passage of the fuel injector;
- and
- varying a rate of the injection of the fuel in response to the adjustment of the injection rate controller.
2 more elements
Dependencies are inferred from the claim text.