| 摘要 |
To provide a valve stroke or displacement characteristic with respect to closing force which is at first rapidly dropping and then, after a minimum closing force is reached again increasing, so that, as the valve needle reaches its final stroke, a hard impact is avoided and rapid closure of the valve, upon drop of injection pressure, will result, a magnet circuit (88) is established in the valve housing by a magnetic element (50) and an armature (66), one of the elements being seated in the housing and the other being coupled to the valve needle (18) to provide a closure force-versus-displacement characteristics which at first drops sharply and then flattens. Further magnetic elements formed by two magnets (70, 80), with like poles facing each other are provided, to furnish the closing force-versus-displacement characteristics which increases with increasing displacement, the composite of the two forces acting on the valve being in the form of a hanging curve (FIG. 2: 98) having a minimum (F6) approximately midway along the length of the stoke of the valve needle (18).
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