초록

In an injection system with pressure intensification with a simple and space-saving design, control means are provided permitting a large range fuel injection pressure control, which also permits rapid adaptation of the fuel injection pressure to the various engine operating conditions.

대표청구항 ▼

In an injection system with pressure intensification with a simple and space-saving design, control means are provided permitting a large range fuel injection pressure control, which also permits rapid adaptation of the fuel injection pressure to the various engine operating conditions. able drops b

In an injection system with pressure intensification with a simple and space-saving design, control means are provided permitting a large range fuel injection pressure control, which also permits rapid adaptation of the fuel injection pressure to the various engine operating conditions. able drops by a pregiven value within a pregiven time. 4. A method for checking the tightness of a tank-venting system of a vehicle, the method comprising the steps of: introducing an overpressure or underpressure compared to the atmospheric pressure utilizing a pressure source alternately into the tank-venting system and a reference leak of a defined size connected in parallel to the tank-venting system over a pregiven time interval; detecting at least one operating characteristic variable of the pressure source when introducing the pressure into the tank-venting system (tank measurement) as well as when introducing the pressure into the reference leak (reference measurement); comparing the two measurements; drawing a conclusion as to a leak when there is a deviation of the tank measurement from the reference measurement by a pregivable value; drawing a conclusion as to the operability of the tank-venting valve of the tank-venting system from the time-dependent trace of the operating characteristic variable for the tank measurement; detecting the time-dependent trace of the operating characteristic variable during a tank measurement carried out during idle of an internal combustion engine (idle measurement); detecting the time-dependent trace of the operating characteristic variable in a tank measurement executed for a switched off internal combustion engine of the motor vehicle (run-on measurement); and, drawing a conclusion as to a disturbance of the tank-venting valve when the time-dependent gradient of the operating characteristic variable during the idle measurement deviates from the comparable time-dependent gradient of the operating characteristic variable during the run-on measurement by a pregiven value. 5. A method for checking the tightness of a tank-venting system of a vehicle, the method comprising the steps of: introducing an overpressure or an underpressure compared to the atmospheric pressure utilizing a pressure source into the tank-venting system; detecting at least one operating characteristic variable of the pressure source when introducing the pressure into the tank-venting system (tank measurement); comparing the measured operating characteristic variable to a threshold, which is derived from operating variables of the control of an engine of the vehicle or is fixedly pregiven; drawing a first conclusion as to the presence of a leak in said tank-venting system when there is a deviation of the tank measurement from the threshold by a pregiven value; and, drawing a second conclusion during tank measurement as to the operability of the tank-venting valve of the tank-venting system from the time-dependent trace of the operating characteristic variable detected during the tank measurement. 6. The method of claim 5, comprising the further step of using, as an operating characteristic variable, at least one of the following variables: the current take-up of the pressure source; the rpm of the pressure source; the voltage applied to the pressure source; and, the pressure generated by the pressure source. 7. A method for checking the tightness of a tank-venting system of a vehicle, the method comprising the steps of: introducing an overpressure or an underpressure compared to the atmospheric pressure utilizing a pressure source into the tank-venting system; detecting at least one operating characteristic variable of the pressure source when introducing the pressure into the tank-venting system (tank measurement); comparing the measured operating characteristic variable to a threshold, which is derived from operating variables of the control of an engine of the vehicle or is fixedly pregiven; drawing a conclusion as to the presence of a leak when there is a deviation of the tank measurement from the threshold by a pregiven value; drawing a conclusion as to the operability of the tank-venting valve of the tank-venting system from the time-dependent trace of the operating characteristic