초록 ▼

A method for regulating the pressure in a fuel accumulator of an internal combustion engine, in particular in a common rail system is described. The provision of different regulating modes for regulating the pressure in the fuel accumulator is known from the related art. The difference between the

A method for regulating the pressure in a fuel accumulator of an internal combustion engine, in particular in a common rail system is described. The provision of different regulating modes for regulating the pressure in the fuel accumulator is known from the related art. The difference between the individual regulating modes is that, in these modes, only one or multiple independent regulating circuits are active simultaneously to regulate the pressure. A switch-over operation between the regulating modes usually takes place on the basis of different operating states of the internal combustion engine. To minimize disturbances in the pressure in the fuel accumulator during a switch-over operation between two regulating modes, the regulating circuits involved in the switch-over operation are disconnected, and the regulating devices of these regulating circuits are supplied with a suitable switch-over input signal that is predetermined for the switch-over operation in question instead of an input signal representing a system deviation.

대표청구항 ▼

What is claimed is: 1. A method for regulating a pressure in a fuel accumulator of an internal combustion engine, comprising: performing a steady-state operation of a pressure regulator according to an instantaneous regulating mode; implementing a switch-over operation for switching the pressure re

What is claimed is: 1. A method for regulating a pressure in a fuel accumulator of an internal combustion engine, comprising: performing a steady-state operation of a pressure regulator according to an instantaneous regulating mode; implementing a switch-over operation for switching the pressure regulator from the instantaneous regulating mode over to a desired future regulating mode in response to a regulating mode signal; and performing the steady-state operation of the pressure regulator according to the future regulating mode; activating at least one regulating circuit in each regulating mode to regulate the pressure; during each steady-state operation of the at least one regulating circuit, driving a regulating device individually assigned to each of the at least one regulating circuit by an input signal representing a system deviation; opening those of the at least one regulating circuit involved in the switch-over operation to perform the switch-over operation according to the implementing of the switch-over operation by activating their respective regulating devices via switch-over input signals that are predetermined individually for each switch-over operation instead of via a previous input signal, the at least one regulating circuit being designed in such a way that the regulating devices are switched in the desired manner from an instantaneous operating state defined by the instantaneous regulating mode over to a future operating state defined by the future regulating mode. 2. The method as recited in claim 1, wherein the switch-over input signals represent predetermined, constant control values that are dimensioned individually depending on the desired switch-over operation. 3. The method as recited in claim 2, wherein the switch-over signals take into account not only the control values, but also an instantaneous rail pressure deviation. 4. The method as recited in claim 1, wherein a transition of the regulating devices from the instantaneous operating state to the future operating state is monitored on the basis of a shift in an operating point of the respective regulating device caused by the switch-over input signals. 5. The method as recited in claim 1, wherein a first, second and third regulating mode are available as alternatives, only a first regulating circuit being activated in a first regulating mode, only a second regulating circuit being activated in a second regulating mode, and both the first and the second regulating circuits being activated in a third regulating mode to regulate the pressure. 6. The method as recited in claim 5, wherein during a switch-over operation from the third regulating mode to the first regulating mode or the second regulating mode, performing the following: opening the first and second regulating circuits by controlling both the regulating device to be deactivated during the switch-over operation and the one remaining active, via the same switch-over input signals representing the predetermined control values instead of via the input signals from the instantaneous steady-state regulating operation; monitoring the shift in the operating points of the regulating devices caused by the switch-over input signals and performance of the following steps when the regulating device to be deactivated leaves its instantaneous active operating range: shutting off the previous switch-over input signal representing the preset control values for the regulating circuit which remains active, and closing of this regulating circuit by activating its regulating device via a different input signal that is predefined according to the performing of the steady-state operation of the pressure regulator according to the future regulating mode and the selected future first or second regulating mode and represents a system deviation; and continuing control of the regulating device of the regulating circuit to be deactivated via the switch-over input signals until its regulating device has been deactivated on the basis of the operating point shift; and, during the performing of the steady-state operation of the pressure regulator according to the future regulating mode, maintaining the deactivated regulating circuit in the deactivated state either by continuing to suitably activate it via the switch-over input signal, or by shutting down this regulating circuit preferably to a standby mode. 7. The method as recited in claim 5, wherein the switch-over operation from the instantaneous first regulating mode or second regulating mode to the third regulating mode includes performing the following: controlling the regulating device that is currently deactivated in the instantaneous regulating mode and is to be activated for the future regulating mode via a suitable switch-over input signal; monitoring the shift, produced by the controlling operation, in the operating point of the regulating device of the regulating circuit to be activated to determine when the currently deactivated regulating device returns to an active operating range; and continued controlling of the regulating device to be activated via the switch-over signal beyond the time at which the determination was made according to the monitoring of the shift and simultaneous opening of the regulating circuit, activated during the instantaneous and the future regulating modes, by controlling its regulating device via the same switch-over signal as the regulating device to be activated, until both regulating devices have been switched to an active operating state as provided for the desired future third regulating mode. 8. The method as recited in claim 1, wherein a transition from the instantaneous regulating mode to a future regulating mode includes: performing a switch-over operation from the instantaneous regulating mode to a first other regulating mode; and performing a switch-over operation from the instantaneous regulating mode to a second other regulating mode. 9. The method as recited in claim 5, wherein during operation according to the third regulating mode, the input signals for both regulating devices not only represent a system deviation assigned to its own regulating circuit, but also represent a system deviation assigned to the other regulating circuit. 10. A device for regulating a pressure in a fuel accumulator of an internal combustion engine according to one of multiple available regulating modes, which are switchable from an instantaneous regulating mode over to a future one in response to a regulating mode signal, comprising: at least one first and one second regulating circuit, each having a subtraction device for providing a system deviation and each having a regulating device for regulating the pressure in the fuel accumulator during steady-state regulating operation in response to an input signal representing at least one of the system deviations, the first and/or the second regulating circuit being activated depending on the currently set regulating mode; and a regulation management device that includes the subtraction devices and generates a first and a second switch-over input signal from predetermined control values in response to the regulating mode signal, and to control the first and second regulating devices during a non-steady-state switch-over operation triggered by the regulating mode signal via the switch-over input signals instead of via the input signals, so that the regulating devices are switched in the desired manner from an instantaneous operating state defined by the instantaneous regulating mode over to a future operating state defined by the future regulating mode. 11. The device as recited in claim 10, wherein: the first regulating circuit includes not only the first regulating device, but also a throttle valve as an actuator for setting the fuel volume supplied to a fuel pump, connected to the fuel accumulator, for pumping fuel into the fuel accumulator a first of the two subtraction devices provides a first system deviation in the form of a volume deviation between the fuel volume currently provided by the throttle value in the form of an actual variable and a predefined setpoint fuel volume; and the first regulating device indirectly regulates the pressure in the fuel accumulator during a steady-state regulating operation by suitably controlling the throttle valve in response to the input signal that is generated by a first switch-over device assigned to the regulation management device and represents at least the volume deviation. 12. The device as recited in claim 10, wherein: the second regulating circuit includes not only the second regulating device but also a pressure regulating valve as an actuator connected to the fuel accumulator; the second of the two subtraction devices provides a pressure deviation between the instantaneous pressure in the fuel accumulator and a predefined setpoint pressure; and the second regulating device directly regulates the pressure in the fuel accumulator during a steady-state regulating operation via the pressure regulating valve in response to the second input signal that is generated by a second switch-over device assigned to the regulation management device and that represents at least the pressure deviation. 13. The device as recited in claim 12, wherein: during a first regulating mode in which the pressure in the fuel accumulator is regulated only with the help of the first regulating circuit, the first switch-over device is designed to form the input signal for the first regulating device in response to a first control signal of a control device assigned to the regulation management device so that it represents the pressure deviation provided by the second subtraction device; and the second switch-over device forms the input signal for the second regulating device in response to a second control signal of the control device on the basis of at least one of the preset control values so that the regulating device of the second regulating circuit remains deactivated or is shut down. 14. The device as recited in claim 12, wherein: during a second regulating mode in which the pressure in the fuel accumulator is regulated only with the help of the second regulating circuit, the first switch-over device forms the input signal for the first regulating device in response to a first control signal of a control device, assigned to the regulation management device, on the basis of at least one of the preset control values so that the regulating device of the first regulating circuit remains deactivated or is shut down; and the second switch-over device is designed to form the input signal for the second regulating device in response to a second control signal of the control device so that it represents a pressure deviation currently being provided by the second subtraction device. 15. The device as recited in claim 12, wherein: during a third regulating mode in which the pressure in the fuel accumulator is regulated with the help of the first and second regulating circuits, the first switch-over device is designed to form the input signal for the first regulating device in response to a first control signal of a control device assigned to the regulation management device so that it represents a system deviation which reflects the instantaneous volume deviation provided by the first subtraction device and simultaneously also reflects the instantaneous pressure deviation provided by the second subtraction device; and the second switch-over device is designed to likewise form the input signal for the second regulating device in response to a second control signal of the control device so that it represents a system deviation that reflects the instantaneous pressure deviation and the instantaneous volume deviation. 16. The device as recited in claim 13, wherein: the control device, at least during a switch-over operation initiated by the regulating mode signal, monitors a shift in the operating point of the affected regulating devices caused by controlling them via the switch-over signals and to generate the control signals for controlling the first and second switch-over devices in response to the detected desired shift in the operating points. 17. A computer program having program on a tangible computer readable medium code for a device for regulating a pressure in a fuel accumulator, the program code when executed resulting in a performance of the following: performing a steady-state operation of a pressure regulator according to an instantaneous regulating mode; implementing a switch-over operation for switching the pressure regulator from the instantaneous regulating mode over to a desired future regulating mode in response to a regulating mode signal; and performing the steady-state operation of the pressure regulator according to the future regulating mode; activating at least one regulating circuit in each regulating mode to regulate the pressure; during each steady-state operation of the at least one regulating circuit, driving a regulating device individually assigned to each of the at least one regulating circuit by an input signal representing a system deviation; opening those of the at least one regulating circuit involved in the switch-over operation to perform the switch-over operation according to the implementing of the switch-over operation by activating their respective regulating devices via switch-over input signals that are predetermined individually for each switch-over operation instead of via a previous input signal, the at least one regulating circuit being designed in such a way that the regulating devices are switched in the desired manner from an instantaneous operating state defined by the instantaneous regulating mode over to a future operating state defined by the future regulating mode. 18. The method as recited in claim 1, wherein: the internal combustion engine includes a common rail system. 19. The device as recited in claim 10, wherein: the internal combustion engine includes a common rail system.