| 摘要 |
In the fuel injection device a control piston (7) with a pressure chamber (17) acting in an opening direction and a pressure chamber (15) acting in a closing direction are assigned to the valve needle (6) of an injection valve (4). An electro-hydraulic control circuit with servo valve (31) serves for controlling the injection valve and a safety pilot valve (21). By means of a closing element (22) of the latter a fuel feed line (19) leading to the fuel receiver chamber (20) at the valve needle can be opened and closed. The said feed line branches off from a pressure line (18) leading from a high pressure accumulator (3) to the pressure chamber (15). The servo valve outlet (34) has the pressure chamber (17) connected to it by way of a pressure line (38), and a control pressure chamber (42), acting in the opening direction on the pressure piston (26) of the safety pilot valve, connected to it by way of a control pressure line (44) branching off from the pressure line (38), whereas the servo valve outlet (35) has a control pressure chamber (40), acting in the closing direction on the pressure piston 26, connected to it by way of a pressure line (39). At the other end, the pressure piston (6) has a connecting rod (25) carrying the closing element (22) and passing through the pressure line (18). For opening and closing of the safety pilot valve (21) the control pressure chambers (40, 42) can be alternately pressurised and relieved by the servo valve by way of the hydraulic control circuit, the injection valve (4) responding beforehand owing to the shorter pressure transmission distance. <IMAGE>
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