A fuel injector including a fuel injector housing (2), a valve seat (4) formed at one end of the fuel injector housing (2), and a valve body (10) disposed in the fuel injector housing (2) and operable to open and close a spray hole in the valve seat (4). The valve seat (4) includes a base portion (16) and insert portion (26) having spray holes (8) that is secured to the base portion (16).

A fuel injector is provided that includes various precise configuration parameters, including dimensions, shape and/or relative positioning of fuel injector features, resulting in improved efficiency of fuel flow through the fuel injector.

A sealing structure includes an O-ring and a back-up ring. An outer diameter of the back-up ring is smaller than an inner diameter of a mounting portion of a delivery pipe. An inner diameter of the back-up ring is gradually increased from a pressure-receiving surface toward a seating surface, and is greater than an outer diameter of a fuel introducing portion of a fuel injection valve. In a section of the back-up ring, an edge angle defined between the pressure-receiving surface and an inner circumferential surface is smaller than a gap angle defined between the pressure-receiving surface and a tapered outer surface of a tapered portion in the fuel introducing portion. A dimension of the seating surface in the back-up ring is shorter than a dimension in an end surface.

A fluid injector assembly extending along a longitudinal axis comprising a housing, and an injector positioned within the housing, the injector comprising a injector body having an interior cavity, a plunger positioned within the interior cavity and comprising a plunger body, a fluid delivery passage along at least a portion of the plunger body, and a plunger tip positioned at a downstream end of the plunger body, the fluid delivery passage comprising a longitudinal passage and at least one internal swirl passage, and the internal swirl passage being angled relative to the longitudinal axis and extending from the longitudinal passage to an opening upstream of the plunger tip, and a nozzle positioned at a downstream end of the injector body and including at least one nozzle passage, fluid being delivered from an upstream end of the injector to the at least one nozzle passage through the fluid delivery passage.

A fluid injector includes a fluid inlet; a valve seat located downstream of the fluid inlet and having a valve seat aperture extending therethrough; a valve member moveable between a closed position and an open position to control flow through the valve seat aperture; and director plate including a first aperture and a second aperture extending therethrough. A fluid flow channel is formed between the valve seat and the director plate and extends from an inlet end to an outlet end. The first aperture and the second aperture extend through the director plate from the fluid flow channel. The first aperture is located between the inlet end and the second aperture. The fluid flow channel decreases in cross-sectional area from the inlet end toward the first aperture and the fluid flow channel increases in cross-sectional area from the first aperture toward the second aperture.

A fuel supply nozzle unit includes a fuel supply nozzle, a rear end and an end plate. The fuel supply nozzle includes a front end that has a plurality of fuel supply holes. The rear end extends from the front end and is formed with a threaded portion on its outer surface. The end plate is connected to the rear end and is formed with a plurality of threaded holes.

A fuel supply nozzle unit includes a fuel supply nozzle, a rear end and an end plate. The fuel supply nozzle includes a front end that has a plurality of fuel supply holes. The rear end extends from the front end and is formed with a threaded portion on its outer surface. The end plate is connected to the rear end and is formed with a plurality of threaded holes.

A fluid injector assembly extending along a longitudinal axis comprising a housing, and an injector positioned within the housing, the injector comprising a injector body having an interior cavity, a plunger positioned within the interior cavity and comprising a plunger body, a fluid delivery passage along at least a portion of the plunger body, and a plunger tip positioned at a downstream end of the plunger body, the fluid delivery passage comprising a longitudinal passage and at least one internal swirl passage, and the internal swirl passage being angled relative to the longitudinal axis and extending from the longitudinal passage to an opening upstream of the plunger tip, and a nozzle positioned at a downstream end of the injector body and including at least one nozzle passage, fluid being delivered from an upstream end of the injector to the at least one nozzle passage through the fluid delivery passage.

A fluid injector includes a fluid inlet; a valve seat located downstream of the fluid inlet and having a valve seat aperture extending therethrough; a valve member moveable between a closed position and an open position to control flow through the valve seat aperture; and director plate including a first aperture and a second aperture extending therethrough. A fluid flow channel is formed between the valve seat and the director plate and extends from an inlet end to an outlet end. The first aperture and the second aperture extend through the director plate from the fluid flow channel. The first aperture is located between the inlet end and the second aperture. The fluid flow channel decreases in cross-sectional area from the inlet end toward the first aperture and the fluid flow channel increases in cross-sectional area from the first aperture toward the second aperture.

A sealing structure includes an O-ring and a back-up ring. An outer diameter of the back-up ring is smaller than an inner diameter of a mounting portion of a delivery pipe. An inner diameter of the back-up ring is gradually increased from a pressure-receiving surface toward a seating surface, and is greater than an outer diameter of a fuel introducing portion of a fuel injection valve. In a section of the back-up ring, an edge angle defined between the pressure-receiving surface and an inner circumferential surface is smaller than a gap angle defined between the pressure-receiving surface and a tapered outer surface of a tapered portion in the fuel introducing portion. A dimension of the seating surface in the back-up ring is shorter than a dimension in an end surface.