| 摘要 |
A control valve for the fuel return in an injection line in internal combustion engines, which has a valve tappet which is arranged in a longitudinally displaceable manner and which exposes larger valve cross sections as the opening stroke increases and can be actuated against the restoring force of a valve spring by an electric magnet coil. The opening stroke and hence the valve cross section can be adjusted by a spring assembly having at least two actuating springs which can be deflected in the axial direction of the valve tappet and are arranged in parallel and in such a way that they can be subjected to force in an axially offset manner with the result that different resultant spring forces counteract the actuating movement in successive sections of the spring travel.To allow accurate setting of the valve position, especially in the intermediate positions, the invention makes provision for the actuating travel of the valve tappet to be limited by an axially displaceable stop which is in operative connection with a second actuating drive, independent of the magnet coil, and, in a direction opposed to the actuating drive with the spring assembly.
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