| 摘要 |
The present invention relates to a fuel supply system for diesel engines that comprises a fuel supply pump (5) for discharging the fuel from a tank (1) as well as a fuel filter (7) and a high-pressure pump (9) which are serially connected in fluid communication. This system also includes an assembly mounted in parallel and comprising a plurality of injectors (16) or injection nozzles and an electrically-operated high-pressure control valve (18) with a back-flow duct (20), wherein said assembly is mounted downstream relative to the high-pressure outlet (14) of the high-pressure pump (9). This assembly mounted in parallel is supplied from the high-pressure pump with a fuel flow at a pressure which can be modified according to the needs by actuating a high-pressure control valve. The system further comprises at least one back-flow duct (18) for sending back to the tank (1) the excess fuel from high-pressure control valve and/or the injectors and at least one cooling unit (19, 21) arranged in said back-flow duct. According to the present invention, a first back-flow duct (18) is mounted downstream relative to the injectors while a second back-flow duct (20) is mounted downstream relative to the control valve. At least the second back-flow duct (20) is connected to the cooling unit (21) having its outlet connected to the junction between the fuel pump (5) and the high-pressure pump (9), preferably upstream from the fuel filter. The main advantages of the present invention are the fuel pump discharge, the heating of the fuel filter practically upon starting the engine and a particularly thorough purification of the fuel flow in the high-pressure pump as it circulates through the filter. |
