Abstract: A method of injecting gaseous fuel into an internal combustion engine comprises selecting one of at least two predetermined operating modes as a function of engine load and engine speed. The engine includes a fuel injection valve with an actuator for changing a commanded amplitude for lifting a valve needle during injection, and for changing, from one combustion cycle to the next, the shape of an actuation pulse defined by commanded amplitude plotted against time. In a first operating mode, which corresponds to low load and low speed range, the actuation pulse has a rectangular shape. In a second operating mode, which corresponds to at least one of a greater load and a greater speed range, the actuation pulse includes at least two shape-defining segments with the commanded amplitude for the first segment being less than 90% of the amplitude for a subsequent second segment.

Abstract: A method of operating a gaseous-fueled internal combustion engine comprises selecting one of at least two predetermined operating modes as a function of engine load and engine speed. A first operating mode is selected when said engine is commanded to operate within a first region corresponding to a low load and low speed range, and a second operating mode is selected when said engine is commanded to operate within a second region distinct from said first region and corresponding to at least one of a greater load and a greater speed range compared to said first region. In the first operating mode, the gaseous fuel is introduced in a single injection event with the injection valve commanded to open with a constant amplitude A1. In the second operating mode, the gaseous fuel is introduced in a single injection event and the injection valve is commanded to begin with a constant amplitude A2 for a predetermined time and then to open to an amplitude A3, wherein amplitude A3 is greater than amplitude A2.

Abstract: An internal combustion engine comprises a fuel injection nozzle for injecting a gaseous fuel directly into the combustion chamber. shield, is installed in close proximity to the fuel injection nozzle, provides a shielded space around a hot surface igniter and restricts flow between the shielded space and the combustion chamber. The nozzle comprises a fuel injection port oriented to direct a fuel spray against a surface of the sleeve An inlet in the sleeve allows air and fuel to enter the shielded space to form a combustible mixture therein. The sleeve contains a substantial amount of the combustible mixture within the shielded space until it ignites and pressure builds within the shielded space to propel a combustion flame through at least one discharge opening and into contact with the fuel sprays emerging from the fuel injection nozzle.

Abstract: An internal combustion engine comprises a fuel injection nozzle disposed in a combustion chamber for injecting a gaseous fuel directly into the combustion chamber. An ignition device disposed within the combustion chamber is installed in close proximity to the fuel injection nozzle, and comprises a sleeve that provides a shielded space around a hot surface igniter and the sleeve restricts flow between the shielded space and the combustion chamber. The nozzle comprises a fuel injection port that is oriented to direct a fuel spray to impinge upon a surface of the sleeve at about a 90 degree angle. At least one inlet opening in the sleeve allows air and fuel to enter the shielded space to form a combustible mixture therein.