| 摘要 |
<p>An injection nozzle for an internal combustion engine includes a valve member, (30) having at least first (44), second (46) and third (48) distinct regions, and being engageable with a seating surface (32), which defines a seat cone angle ( theta s), so as to control fuel delivery through a nozzle outlet (36). The second region provides a seat region (46) of part-conical form, which defines a first cone angle ( theta 1). The third region (48), of part-conical form, is arranged immediately downstream of the seat region (46) and defines a second cone angle ( theta 2), the seat and third regions (46) defining, at their intersection, a seating line (40) for engagement with the seating surface (32). A first differential angle between the first cone angle ( theta 1) and the seat cone angle ( theta s) is greater than a second differential angle between the second cone angle ( theta 2) and the seat cone angle ( theta s), said first and second differential angles being selected to ensure the seating line (40) tends to migrate in an upstream direction along the seat region (46) as the valve member (30) is worn, in use. <IMAGE></p> |
