초록 ▼

A system and method for reducing the fuel pressure in a fuel injection system after the internal combustion engine to be supplied has been shut off, in which a high fuel pressure built up in a high-pressure reservoir chamber (common rail) by a high-pressure feed pump, is relieved into the supply tan

A system and method for reducing the fuel pressure in a fuel injection system after the internal combustion engine to be supplied has been shut off, in which a high fuel pressure built up in a high-pressure reservoir chamber (common rail) by a high-pressure feed pump, is relieved into the supply tank via control valves that control the injection event and are provided on the injection valves that communicate with the common rail. For purposes of this pressure relief, the control valves are triggered such that they connect a pressure chamber of the injection valve with the common rail or the supply tank so briefly that the pressure urging the valve member of the injection valves in the opening direction remains below an opening pressure of the injection valves, and this triggering process of the control valves is repeated until a desired pressure in the common rail is reached.

대표청구항 ▼

[ What is claimed:] [1.] A method for reducing the fuel pressure in a fuel injection system for internal combustion engines, in which the fuel injection system includes a pump (1) for feeding fuel into a common rail (7), pressure lines (9) that lead to first and second pressure chambers in injection

[ What is claimed:] [1.] A method for reducing the fuel pressure in a fuel injection system for internal combustion engines, in which the fuel injection system includes a pump (1) for feeding fuel into a common rail (7), pressure lines (9) that lead to first and second pressure chambers in injection valves (11), a valve member in said injection valve, a control valve (31) on the injection valve (11), said method comprising controlling said control valve to control an injection through the injection valve (11) which for the control connects said second pressure chamber (29, 323) of the injection valve (11) that acts upon a valve member (15) of the injection valve (11) with the common rail (7) or a relief line (35) into a supply tank (5), controlling the pressure in the common rail (7), after shutoff of the engine to terminate fuel feeding by the pump (1), controlling the control valve to relieve the supply tank (5) via the control valve (31), connecting the control valve (31) to the pressure chamber (29, 323) of the injection valve (11) briefly with the common rail (7) or the supply tank (5) so that the pressure acting upon the valve member (15) of the injection valve (11) in the opening direction remains below an opening pressure of the injection valve (11), and this triggering operation of the control valve (31, 323) is repeated until a desired reduced pressure in the common rail (7) is attained.