Method and apparatus for regulating voltages and voltage gradients for driving piezoelectric elements
AssigneeRobert Bosch GmbH
InventorsJohannes-Jörg Rueger, Matthias Mrosik, Volker Pitzal, Udo Schulz
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Abstract
The invention describes a method and an apparatus for a fuel injection system with a piezoelectric element for controlling the amount of injected fuel by charging and/or discharging the piezoelectric element, wherein the fuel injection system comprises a current flow controller for charging and/or discharging the piezoelectric element based upon the gradient of a voltage across the piezoelectric element due to a charge the piezoelectric element is carrying.
Claims26
Fuel injection system with a piezoelectric element (10, 20, 30, 40, 50 or 60) for controlling the amount of injected fuel by charging and/or discharging the piezoelectric element (10, 20, 30, 40, 50 or 60), characterized in that the fuel injection system comprises a current flow controller (3000) for charging and/or discharging the piezoelectric element (10, 20, 30, 40, 50 or 60) as a function of a gradient of a voltage across the piezoelectric element (10, 20, 30, 40, 50 or 60) due to an existing charge the piezoelectric element (10, 20, 30, 40, 50 or 60) is carrying.
Fuel injection system with a piezoelectric element (10, 20, 30, 40, 50 or 60) for controlling the amount of injected fuel by charging and/or discharging the piezoelectric element (10, 20, 30, 40, 50 or 60) to a voltage, characterized in that the fuel injection system comprises a voltage controller (3500) for controlling the voltage as a function of a desired and a measured value of the voltage across the piezoelectric element;
- and
- characterized in that the voltage controller (3500) controls the voltage based upon a desired value of the voltage an a measured value of the voltage associated with a former injection.
Method for operating a fuel injection system with a piezoelectric element (10, 20, 30, 40, 50 or 60) for controlling the amount of injected fuel, wherein the amount of injected fuel is controlled by charging and/or discharging the piezoelectric element (10, 20, 30, 40, 50 or 60), characterized in that the piezoelectric element (10, 20, 30, 40, 50 or 60) is charged and/or discharged as a function of a gradient of a voltage across the piezoelectric element ( 0, 20, 30, 40, 50 or 60) due to an existing charge the piezoelectric element is carrying.
An apparatus to at least one of charge and discharge a piezoelectric element to control an amount of fuel injected in a fuel injection system, comprising:
- a current flow controller configured to at least one of charge and discharge the piezoelectric element as a function of a gradient of a voltage across the piezoelectric element due to an existing charge carried by the piezoelectric element.
A fuel injection system, comprising:
- a piezoelectric element, at least one of charging and discharging the piezoelectric element controlling an amount of fuel injected into the system;
- and
- a current flow controller configured to at least one of charge and discharge the piezoelectric element as a function of a gradient of a voltage across the piezoelectric element due to an existing charge the piezoelectric element is carrying.
A apparatus controlling a voltage at least one of charged and discharged across a piezoelectric element to control an amount of fuel injected in a fuel injection system, comprising:
- a voltage controller configured to control the voltage as a function of a desired value and a measured value of the voltage across the piezoelectric element;
- wherein the desired value and the measured value of the voltage are the desired value and the measured value of the voltage from a prior injection.
A method for operating a fuel injection system, comprising the step of:
- determining at least one of a charge and a discharge of a piezoelectric element to control an amount of fuel injected in the system as a function of a gradient of a voltage across the piezoelectric element due to an existing charge carried by the piezoelectric element.
Dependencies are inferred from the claim text.