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AssigneeRobert Bosch GmbH
InventorsHelmut Rembold, Jens Wolber, Uwe Mueller, Markus Amler
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A fuel system (10) serves to supply fuel (18) to an internal combustion engine. The fuel system includes a reservoir (16) and a first fuel pump (20) whose input is connected to the reservoir (16). In addition, a second fuel pump (38) is provided, whose input is connected to the first fuel pump (20). Furthermore, at least one injection valve (50) is provided, which is connected to the second fuel pump (38) and can supply fuel at least indirectly to a combustion chamber. A leakage line (68) is provided between the second fuel pump (38) and the reservoir (16). In order to permit a reliable hot start of the engine with a simultaneously low strain on the components, the invention proposes that the leakage line (68) be provided with a valve device (70), which has a shutoff function (72) and a pressure relief function (74) that are connected in parallel with each other.
A fuel system (10) for supplying fuel (18) to an internal combustion engine, with a reservoir (16), a first fuel pump (20) whose input is connected to the reservoir (16), a second fuel pump (38) whose input is connected to the first fuel pump (20), at least one injection valve (50), which is connected to the second fuel pump (38) and can supply fuel (18) at least indirectly into a combustion chamber, and a leakage line provided between the second fuel pump and the reservoir, characterized in that the leakage line (68) contains a valve device (70), with a shutoff function (72) and a pressure relief function (74) that are connected in parallel with each other.
The fuel system (10) according to one of the preceding claims, characterized in that the shutoff function (72) of the valve device (70) can be electrically triggered.
The fuel system (10) according to one of the preceding claims, characterized in that the valve device (70) is situated in the vicinity of the engine, in particular in the vicinity of the second fuel pump (38).
The fuel system (10) according to one of the preceding claims, characterized in that the valve device (70) is situated in the vicinity of the reservoir (16) and the second fuel pump (38) is provided with a bypass line (110) that contains a throttle restriction (112) and leads from the input of the second fuel pump (38) to the leakage line (68), and the cross section of the throttle restriction (112) is selected so that during normal operation, the increase in the temperature of the fuel (18) in the reservoir (16) is less than a limit value.
A method for operating the fuel system (10) according to one of the preceding claims, characterized in that the shutoff function (72) of the valve device (70) is activated immediately after the engine is turned off and is deactivated immediately after the engine is started.
Dependencies are inferred from the claim text.