Abstract: A fuel injection valve and director plate assembly including a circular beveled valve seat, a valve ball for forming a circular sealing line against the seat, and a perforated director plate. The improved valve seat is substantially thicker than a prior art seat to provide greater mass of seat material and hence reduced vulnerability of the seat to thermal distortion from welding. To obviate an increase in residual fuel volume that would result from displacing the director plate from the valve by the added thickness of the seat, the central portion of an improved director plate is made concave such that the actual fuel-directing portion of the director plate is to the valve ball in the prior art relationship, thus preserving the desirably small prior art volume of residual fuel after valve closing.

Abstract: A method for fabricating a flow passage in a director plate is presented, comprising placing a director plate and a sacrificial strip immediately adjacent a surface of the director plate in a stamping tool. The director plate is clamped to the sacrificial strip, and a flow passage is created in the director plate by punching a tool piece substantially completely through a predetermined location on the director plate. The flow passage in said director plate may comprise a fluid-discharge orifice for a fuel injector. The flow passage may be punched substantially orthogonal to the planar surface of the director plate, or, alternatively, oblique to the planar surface of the director plate.

Abstract: A director plate for a fuel injector for use in an internal combustion engine. A plurality of fuel passages extend through the plate between an inlet surface and an exit surface. The passage and exit surfaces are extremely smooth, having an average surface roughness (Ra) less than about 0.2 ?m, and preferably less than about 0.1 ?m. The corners of the exits are sharp and are free of features such as break-edges, burrs, and remelt. The surface quality may be obtained via any means of surface finishing.