| 摘要 |
The present invention relates to a fuel injection system for an internal combustion engine with a fuel injector, said injector comprising an inlet port (2); a spill port (3); a pressure intensifier comprised of a piston (6) forming a working chamber (10) and plunger (7) adapted for injecting fuel through a nozzle (14); an hydraulic valve (4) comprising a control chamber (5) and a poppet chamber (27) and having a poppet (25) located between the inlet port (2) and the working chamber (10) and opening into the working chamber (10), wherein said poppet (25) provides a throttling slot (28); a means (31) for biasing the hydraulic valve (4) towards its closed position; a control valve (21) installed between the control chamber (5) and the spill port (3); a bypass channel (29) for connection of the poppet chamber (27) to the control chamber (5). The invention is characterized in that the hydraulic valve (4) is adapted to control the flow area of said bypass channel (29) such that the bypass channel (29) is open when the hydraulic valve (4) is in its closed and open positions or near these positions and closed during the other positions of the hydraulic valve (4). By means of the invention, an improved fuel injector having an increased range of electronic control of an injection curve shape, improved stability of fuel delivery and a simplified design is accomplished.
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