A fuel injector includes an injector body and a valve stack within the injector body that includes a valve seat plate. The valve seat plate includes a pressure control passage for controlling fuel injection, and a valve seat positioned fluidly between the pressure control passage and a low-pressure drain. The valve seat plate includes a pressure-limiting annular groove that extends circumferentially around the valve seat and axially inward from a side of the valve seat plate where the valve seat is located. The groove enables deformation in response to pressure differences across the valve seat plate in a manner that limits stress concentrations.

A fuel injector includes an injector housing having a nozzle assembly with a nozzle piece, and a nested check assembly of an outer check and an inner check. Spray orifices are formed in the nozzle piece in a first orifice set equipped with a first spray duct set and a second orifice set equipped with a second spray duct set. The inner check can be opened to spray fuel from the first orifice set and the outer check can be opened to spray fuel from both the first orifice set and the second orifice set. The outer check is non-rotating while the inner check can be permitted to rotate during service. Spray ducts associated with the first orifice set may have a different duct length and duct inside diameter than spray ducts associated with the second orifice set. The first orifice set may include lower-flow spray orifices and the second orifice set may include higher-flow spray orifices. Related methodology is also disclosed.

An internal combustion engine includes a piston and a fuel injection valve. The fuel injection valve includes a first injection hole, a second injection hole, a first needle configured to open and close the first injection hole, and a second needle configured to open and close the second injection hole. The first injection hole and the second injection hole are configured such that a portion of a fuel spray injected from the first injection hole and a portion of a fuel spray injected from the second injection hole overlap each other at a position apart at a predetermined distance from a side wall of a cavity of the piston. The second needle is configured to start operation in order to open the second injection hole after a predetermined time has elapsed from a point of time when the first needle starts operation in order to open the first injection hole.

A fuel injection valve has first injection holes, second injection holes, a first needle that opens and closes the first injection holes, and a second needle. The fuel injection valve is arranged such that a part of fuel injected from the first injection hole and a part of fuel injected from the second injection hole are gathered together at a position spaced from the side wall of the cavity by a predetermined distance. The second needle starts operating to open the second injection holes, after a predetermined time elapses from a point in time at which the first needle starts operating to open the first injection holes.

A fuel injector is provided that creates variable spray characteristics to effectively reduce emissions, such as NOx emissions and particulate matter. The injector includes a nozzle valve element of the outwardly opening type including a fuel delivery passage and spray holes. The nozzle valve element is operable to move to a low lift position to cause fuel flowing from the spray holes to impinge on the injector body and to deflect toward the combustion chamber, and to move to a high lift position to cause fuel flowing from the spray holes to avoid impingement on injector body and flow in an obstructed manner directly into the combustion chamber. An annular chamber may be formed in the nozzle valve element adjacent the spray holes to receive fuel.

A fuel injector body includes a body that includes an at least partially annular configuration defining a longitudinal axis, a circumferential direction, and a radial direction. A first counterbore and a first cavity extend from the first end toward the second end, and an external interface portion including a sealing surface is disposed axially between the first end and a shoulder. The first cavity defines a bottom surface and a peripheral surface, and the body also includes a leak passage extending from the bottom surface that is in communication with the first cavity.

A handheld combustion powered fastening tool may include a driving system that drives fasteners into workpieces in response to combustion of fuel by the driving system. A fuel delivery system may supply fuel to the driving system. The fuel delivery system may include a fuel canister storing liquid fuel, such as liquid hydrocarbons such as propane, and a fuel metering valve supplying a previously set amount, or volume, of fuel from the fuel canister to the driving system for combustion.

The present device involves a fuel injector nozzle and control system for delivering a fine atomized fuel that is evenly mixed throughout the compressed air charge across a wide range of throttle positions. The system includes a pintle rod that is incrementally moveable to release a high pressure atomized stream of fuel through one or more apertures to vary the size of the opening through which the fuel is directed into the compressed air charge. The atomized fuel is delivered in a manner that allows the fine particles of fuel to be evenly distributed throughout the compressed air charge for more complete and consistent combustion.

A fuel injector includes an injector housing having a nozzle assembly with a nozzle piece, and a nested check assembly of an outer check and an inner check. Spray orifices are formed in the nozzle piece in a first orifice set equipped with a first spray duct set and a second orifice set equipped with a second spray duct set. The inner check can be opened to spray fuel from the first orifice set and the outer check can be opened to spray fuel from both the first orifice set and the second orifice set. The outer check is non-rotating while the inner check can be permitted to rotate during service. Spray ducts associated with the first orifice set may have a different duct length and duct inside diameter than spray ducts associated with the second orifice set. The first orifice set may include lower-flow spray orifices and the second orifice set may include higher-flow spray orifices. Related methodology is also disclosed.

A fuel injector includes an injector body and a valve stack within the injector body that includes a valve seat plate. The valve seat plate includes a pressure control passage for controlling fuel injection, and a valve seat positioned fluidly between the pressure control passage and a low-pressure drain. The valve seat plate includes a pressure-limiting annular groove that extends circumferentially around the valve seat and axially inward from a side of the valve seat plate where the valve seat is located. The groove enables deformation in response to pressure differences across the valve seat plate in a manner that limits stress concentrations.