Abstract: In an internal combustion engine, the fuel is conveyed by an electrically driven fuel pump. The intake side of this pump is connected to a fuel tank and its outlet side is connected to a pressure region. A prerun of the electrically driven fuel pump may be performed before the startup of the internal combustion engine. In order to increase the service life of the fuel pump, an actual pressure (pactual) in the pressure region may be detected by a pressure sensor and the execution of the prerun be a function of at least the signal of the pressure sensor.

Abstract: A first method for determining a variable, which characterizes a fuel injection, in an internal combustion engine of a motor vehicle in a hot-start situation wherein fuel is injected directly into at least one combustion chamber from a high-pressure region of a fuel supply system; the variable, which characterizes the injection quantity, is corrected at least in dependence upon a variable, which represents a temperature of the fuel. A second method is for determining a hot-start situation in an internal combustion engine of a motor vehicle wherein a hot-start situation is determined at least based on a variable, which represents a temperature of the fuel, and based on a fuel pressure. The invention relates likewise to corresponding arrangements, a corresponding control apparatus for an internal combustion engine, a corresponding computer program having program-code means and a corresponding computer program product having program-code means.

Abstract: Method for varying a prepressure (p_des) generated by a low-pressure pump and applied to a high-pressure pump with the low-pressure pump (2) and the high-pressure pump (3) pumping fuel for the internal combustion engine (1). In order to keep the prepressure (p_des), on the one hand, as low as possible to take load off the low-pressure pump (2) and to, on the other hand, adjust the prepressure (p_des) so high that a vaporization of the fuel is reliably avoided, the invention suggests that: the actual temperature (T_Krst) of the fuel in the high-pressure pump (3) is determined; a prepressure (p_des) as low as possible is determined in dependence upon the fuel temperature (T_Krst) for which a vaporization of the fuel in the high-pressure pump (3) is reliably avoided; and, the low-pressure pump (2) is so driven or controlled that it generates the determined prepressure (p_des). The method is preferably carried out on the basis of physical models of the high-pressure pump (3).

Abstract: The invention relates to a method for reducing the fuel pressure in a return-free fuel supply system of an internal combustion engine to a desired pressure value. At least one fuel pump is mounted in the fuel supply system. In order to be able to reduce the fuel pressure in the fuel supply system in a simple manner without additional pressure release valves, the suggestion is made that the fuel supply system and the internal combustion engine be operated in a pressure-reduction mode wherein at least one fuel pump of the fuel supply system is so controlled (open loop and/or closed loop) that the desired pressure value is adjusted in the fuel supply system. The fuel supply system is preferably configured as a common-rail storage injection system for a direct-injecting internal combustion engine.

Abstract: A method for cooling a fuel injection system and fuel injection systems are proposed that improve the hot-starting performance of the internal combustion engine.

Abstract: 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.

Abstract: A method is used for operating an internal combustion engine (10), in particular of a motor vehicle. In the method, at least one fuel pump (22, 32) delivers the fuel from a fuel tank (28) into a fuel line (20, 24, 26, 34). The pressure of the fuel, at least in a region (26) of the fuel line (20, 24, 26, 34), is increased as a function of an operating state. In order to assure a reliable starting of the engine (10), the pressure of the fuel, at least in the above-mentioned region (26) of the fuel line (20, 24, 26, 34), is at least intermittently increased (75) when the engine (10) is not running.

Abstract: An injection system for internal combustion engines is proposed, in which once the engine has been turned off, a pressure equalization is established between the intake side and the pressure side of the high-pressure fuel pump. This prevents uncombusted fuel from reaching the combustion chambers of the engine. The pressure prevailing on the pressure side and the intake side when the engine is off furthermore assures that vapor bubbles cannot form, and this makes starting the engine easier.

Abstract: In an internal combustion engine, the fuel reaches the combustion chamber of the engine via a fuel-injection device which includes a piezo actuator (50). In order to be able to optimally inject the fuel, it is suggested that the desired level (U_DES) of the drive energy (U) and/or the desired gradient (dU_DES) of the drive energy (U), with which the piezo actuator (50) is driven, is dependent upon a plurality of influence quantities (T, t, n, dx, dh) which influence the operating behavior of the piezo actuator (50).

Abstract: A method and a device are described for diagnosing a fuel system having a plurality of electric fuel delivery units, which are submerged on the inlet side in a fuel supply contained in a fuel tank, and which, on the outlet side, deliver fuel in a fuel line to an internal combustion engine. The currents of the electric fuel delivery units are measured directly or indirectly in an analysis unit, compared to one another, and a diagnostic signal in digitized form is generated as a function of the result of the comparison.

Abstract: The invention relates to a method and an arrangement for calibrating a pressure sensor (7) of a fuel-metering system of an internal combustion engine wherein the fuel-metering system includes: a high-pressure pump (2) for pumping fuel from a low-pressure region (ND) into a high-pressure region (HD) injectors (5) for metering the fuel from the high-pressure region (HD) into combustion chambers (6) of the internal combustion engine with the injectors (5) being drivable in dependence upon operating characteristic variables, and the pressure sensor (7) for measuring the pressure in the high-pressure region (HD).

Abstract: In the case of a method for operating an internal combustion engine (10), in particular of a motor vehicle, fuel is supplied under pressure via at least one injection valve (18). The injected fuel quantity is influenced by the injection time of injection valve (18). In order to be able to provide optimum operating comfort and good component reliability even in the event of an incorrect fuel pressure (pr), it is proposed to determine a maximum allowable torque (mimxth) of the internal combustion engine (10) that is dependent on the instantaneous fuel pressure (pr).

Abstract: The invention relates to a fuel delivery system for an internal combustion engine, having a fuel feed pump (10), which delivers fuel which is at pilot pressure to a high-pressure fuel pump (11) that communicates on the high-pressure side with at least one injection valve (14), in order to deliver fuel at high pressure to the injection valve or valves (14). To prevent vapor bubble development in the high-pressure fuel pump (11), which impairs its pumping capacity and pressure generation, it is provided according to the invention that a coolant medium flow can be delivered to the high-pressure fuel pump (11) via at least one coolant conduit (21, 31), in order to keep the temperature (THDP) of the high-pressure fuel pump (11) below a critical operating temperature (Tk1).

Abstract: A fuel supply device for an internal combustion engine of a motor vehicle has a supply container, a feeding aggregate which is electric-motor driven and feeds fuel from the supply container to an injection device of the internal combustion engine, a pressure sensor which determines a fuel pressure downstream of the feeding aggregate, a control device connected with the pressure sensor and controlling an operation of the feeding aggregate so that a fuel pressure is at least approximately below a nominal pressure, a throttled discharge arranged downstream of the feeding aggregate, a valve device operative for controlling the discharge depending on a fuel pressure and opening the discharge when a fuel pressure located under the nominal pressure is exceeded, and a check valve integrated in the feeding aggregate.

Abstract: An operating device for an internal combustion engine of a motor vehicle with a starter having an electric motor, the operating device has a fuel pump; and a connection of said fuel pump with the electric motor so that the electric motor can be used additionally at least indirectly for driving of said fuel pump.

Abstract: A method for cooling a fuel injection system and fuel injection systems are proposed that improve the hot-starting performance of the internal combustion engine.

Abstract: The fuel supply apparatus for supplying fuel to an internal combustion engine has a fuel tank (2), a first fuel pump (6) that supplies fuel from the fuel tank to a fuel line (10), a second fuel pump (12) that supplies fuel from the fuel line (10) via a pressurized line to at least one fuel valve (16) and a fuel return line (22) that connects the fuel line (10) to the fuel tank for return of excess fuel. A shut off valve (30), which is closed at high temperatures, and a pressure regulator valve (26) are arranged hydraulically in series in the fuel return line (22). A fuel scavenger line (60) is provided, by which fuel at high temperatures is returned to the fuel tank (2). The fuel scavenger line (60) conducts the fuel back to the fuel tank (2), at least partially through the second fuel pump (12) and through a hydraulic resistance. Gas bubble formation is prevented by a high fuel supply pressure and by transfer of heat from the second fuel pump (12).

Abstract: A fuel supply system for supplying an internal combustion engine has a consumption-controlled fuel feeding module which at a suction side is connected with a supply tank and at the pressure side is connected with an internal combustion engine. At pressure side of the fuel feeding module a return conduit is leads to at least one pump for filling of the fuel feeding aggregate. A preliminarily supplied return is blockable by a switchable adjusting member which adjusts the return quantity with an open switchable adjusting member by means of a throttle element in all operational conditions above a minimal pump consumption.

Abstract: The invention is directed to a method and an arrangement for operating a fuel supply system (10) and especially a fuel supply system of an internal combustion engine of a motor vehicle. Fuel is pumped into an accumulator (19) with the aid of pumps (13, 24) and the fuel is adjusted at least to a first pressure (P1) or a second pressure (P2). Initially, the first pressure (P1) is adjusted and a pressure signal (PS1) is detected and, thereafter, the second pressure (P2) is adjusted and a pressure signal (PS2) is detected. A pressure difference (&Dgr;P) is formed from the detected first and second pressure signals (PS1, PS2). If the pressure difference &Dgr;P deviates from an expected pressure difference (&Dgr;P_E) by more than a threshold value (S), then a fault in the fuel supply system (10) is detected and stored.

Abstract: A method and a device are described for diagnosing a fuel system having a plurality of electric fuel delivery units, which are submerged on the inlet side in a fuel supply contained in a fuel tank, and which, on the outlet side, deliver fuel in a fuel line to an internal combustion engine. The currents of the electric fuel delivery units are measured directly or indirectly in an analysis unit, compared to one another, and a diagnostic signal in digitized form is generated as a function of the result of the comparison.