Method for controlling a fuel supplying device of an internal combustion engine
View Patent ↗Disclosed is a fuel supplying device of an internal combustion engine, comprising a low-pressure circuit, a high-pressure pump coupled to the low-pressure circuit and conveys fuel into a fuel reservoir, a volume flow control valve assigned to the high-pressure pump, an electromechanical pressure regulator connected to the fuel reservoir and the low-pressure circuit and can direct fuel from the fuel reservoir into the low-pressure circuit, a regulating mechanism which generates an actuation signal for the volume flow control valve by a first controller in a first mode which generating an actuation signal for the electromechanical pressure regulator with the aid of a second controller in a second mode. The mode of the fuel supplying mechanism is switched in accordance with a fuel pressure error value resulting from a detected fuel pressure and a predefined fuel pressure. The mode can additionally be switched according to the throughput of the high-pressure pump.
1. A method for controlling a fuel supplying device of an internal combustion engine, comprising:
connecting a fuel input to a high-pressure fuel pump having a volume flow control valve to a low-pressure fuel circuit;
pressurizing the fuel by the high-pressure fuel pump;
delivering the pressurized fuel into a fuel accumulator;
connecting an electromechanical pressure regulator to the fuel accumulator and the low-pressure fuel circuit where the electromechanical pressure regulator is configured to stop the flow of fuel from the fuel accumulator into the low-pressure fuel circuit;
determining a control deviation from a difference between a specified fuel pressure and a detected fuel pressure;
generating in a first operating mode a regulating signal for the volume flow control valve by a first regulator;
providing in the first operating mode the control deviation to the first regulator;
generating in a second operating mode a regulating signal for the electromechanical pressure regulator by a second regulator;
providing in the second operating mode the control deviation to the second regulator;
switching from the first operating mode to the second operating mode if the detected fuel pressure is greater than the specified fuel pressure by a first specified amount or a first specified factor;
switching from the first operating mode to the second operating mode if the delivery flow of the high-pressure pump is less than a lower switch-over threshold of the delivery flow; and
switching from the second operating mode to the first operating mode if the delivery flow of the high-pressure pump is greater than an upper switch-over threshold of the delivery flow.
2. The method as claimed in claim 1 , wherein a changeover from the second operating mode to the first operating mode occurs if the detected fuel pressure is less than the specified fuel pressure by a second specified amount or a second specified factor.
3. The method as claimed in claim 1 , wherein the lower switch-over threshold of the delivery flow and the upper switch-over threshold of the delivery flow are determined from an error value of a leakage flow through the volume flow control valve in a closed position and a leakage flow from the fuel accumulator if the electromechanical pressure regulator is closed.
4. A method for controlling a fuel supplying device of an internal combustion engine, comprising:
connecting a fuel input to a high-pressure fuel pump having a volume flow control valve to a low-pressure fuel circuit;
pressurizing the fuel by the high-pressure fuel pump;
delivering the pressurized fuel into a fuel accumulator;
connecting an electromechanical pressure regulator to the fuel accumulator and the low-pressure fuel circuit where the electromechanical pressure regulator can stop the flow of fuel from the fuel accumulator into the low-pressure fuel circuit;
determining a control deviation from a difference between a specified fuel pressure and a detected fuel pressure;
generating in a first operating mode a regulating signal for the volume flow control valve by a first regulator;
providing in the first operating mode the control deviation to the first regulator;
generating in a second operating mode a regulating signal for the electromechanical pressure regulator by a second regulator;
providing in the second operating mode the control deviation to the second regulator;
switching from the second operating mode to the first operating mode if the detected fuel pressure is less than the specified fuel pressure by a second specified amount or a second specified factors;
switching from the first operating mode to the second operating mode if the delivery flow of the high-pressure pump is less than a lower switch-over threshold of the delivery flow; and
switching from the second operating mode to the first operating mode if the delivery flow of the high-pressure pump is greater than an upper switch-over threshold of the delivery flow.
5. The method as claimed in claim 4 , wherein the lower switch-over threshold of the delivery flow and the upper switch-over threshold of the delivery flow are determined from an error value of a leakage flow through the volume flow control valve in a closed position and a leakage flow from the fuel accumulator if the electromechanical pressure regulator is closed and no fuel is delivered.
6. The method as claimed in claim 5 , wherein:
the error value of the flow of fuel is determined as a function of a plurality of fuel pressures detected at different times and are detected in a third operating mode where no fuel is delivered, and
the volume flow control valve and the electromechanical pressure regulator are controlled in such a way that the volume flow control valve arid the electromechanical pressure regulator are closed.
7. The method as claimed in claim 6 , wherein:
the fad pressure in the fuel accumulator is regulated to a first specified fuel pressure such that the control deviation is less than a specified threshold value,
a first fuel pressure is detected,
the third operating mode is adjusted and the operating mode switch-over is blocked,
a second fuel pressure is detected, and
the error value of the flow of fuel is determined as a function of a time and a difference between the second detected fuel pressure and the first detected fuel pressure.
8. The method as claimed in claim 7 , wherein the second fuel pressure is detected if the fuel pressure in the fuel accumulator is greater than or equal to a second specified fuel pressure, of which the value is greater than that of the first specified fuel pressure.
9. The method as claimed in claim 8 , wherein the second fuel pressure is detected after a specified time has elapsed.
10. The method as claimed in claim 9 , wherein following a switch from the first operating mode to the second operating mode or from the second operating mode to the first operating mode switch-over of the operating mode is blocked for at least one specified blocking time.
11. A method for controlling a fuel supplying device of an internal combustion engine, comprising:
connecting a fuel input to a high-pressure fuel pump having a volume flow control valve to a low-pressure fuel circuit;
pressurizing the fuel by the high-pressure fuel pump;
delivering the pressurized fuel into a fuel accumulator;
connecting an electromechanical pressure regulator to the fuel accumulator and the low-pressure fuel circuit where the electromechanical pressure regulator can stop the flow of fuel from the fuel accumulator into the low-pressure fuel circuit;
determining a control deviation from a difference between a specified fuel pressure and a detected fuel pressure;
generating in a first operating mode a regulating signal for the volume flow control valve by a first regulator;
providing in the first operating mode the control deviation to the first regulator;
generating in a second operating mode a regulating signal for the electromechanical pressure regulator by a second regulator;
providing in the second operating mode the control deviation to the second regulator; and
performing a mode switch selected from the group consisting of:
(a) switching from the first operating mode to the second operating mode if the detected fuel pressure is greater than the specified fuel pressure by a first specified amount or a first specified factor,
(b) switching from the first operating mode to the second operating mode if the delivery flow of the high-pressure pump is less than a lower switch-over threshold of the delivery flow, and
(c) switching from the second operating mode to the first operating mode if the delivery flow of the high-pressure pump is greater than an upper switch-over threshold of the delivery flow,
wherein the lower switch-over threshold of the delivery flow and the upper switch-over threshold of the delivery flow are determined from an error value of a leakage flow through the volume flow control valve in a closed position and a leakage flow from the fuel accumulator if the electromechanical pressure regulator is closed and no fuel is to be delivered.
12. The method as claimed in claim 11 , wherein there is a switch from the second operating mode to the first operating mode if the detected fuel pressure is less than the specified fuel pressure by a second specified amount or a second specified factor.
13. The method as claimed in claim 11 , wherein:
the error value of the flow of fuel is determined as a function of a plurality of fuel pressures detected at different times and are detected in a third operating mode where no fuel is delivered, and
the volume flow control valve and the electromechanical pressure regulator are controlled in such a way that the volume flow control valve and the electromechanical pressure regulator are closed.
14. The method as claimed in claim 11 , wherein:
the fuel pressure in the fuel accumulator is regulated to a first specified fuel pressure such that the control deviation is less than a specified threshold value,
a first fuel pressure is detected,
the third operating mode is adjusted and the operating mode switch-over is blocked, a second fuel pressure is detected, and
the error value of the flow of fuel is determined as a function of a time and a difference between the second detected fuel pressure and the first detected fuel pressure.
15. The method as claimed in claim 14 , wherein the second detected fuel pressure is detected if the fuel pressure in the fuel accumulator is greater than or equal to a second specified fuel pressure, of which the value is greater than that of the first specified fuel pressure.
16. The method as claimed in claim 15 , wherein the second fuel pressure is detected after a specified time has elapsed.
17. The method as claimed in claim 16 , wherein following a switch from the first operating mode to the second operating mode or from the second operating mode to the first operating mode switch-over of the operating mode is blocked for at least one specified blocking time.