Piezoelectric Drive Actuation Circuit for Engine Injection Nozzles
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Solution Overview
Problem
Existing systems for actuating piezoelectric drives in internal combustion engine injection nozzles require significant intervention in control programs to increase power, which is complex and inefficient.
Innovation Solution
A capacitive equivalent load is connected to the charging and discharging circuits, with a changeover switch allowing the control circuit to simulate the piezoelectric actuating drive, enabling delayed discharge through an additional discharging stage without altering the control device's operation, using parameters like engine load to extend injection nozzle opening intervals.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If the opening times of the injection nozzles are extended to increase the injected fuel quantity and power, then the power of the internal combustion engine increases, but the control program of the control device requires massive intervention which increases device complexity
Solution Approach 1:
A capacitive equivalent load is introduced as an intermediary between the control device and the piezoelectric actuating drive. The equivalent load electrically simulates the piezoelectric actuating drive during charging, allowing the control device to operate without program modifications. A changeover switch enables selective connection between the equivalent load and the actual piezoelectric drive, mediating the power increase function while preserving the original control logic.
Solution Approach 2:
The capacitive equivalent load creates an electrical copy or simulation of the piezoelectric actuating drive's charging characteristics. This copy allows the control device to interact with a simulated load that matches the original drive's electrical behavior, enabling extended opening times without requiring changes to the control program's charging sequences or timing parameters.
2Duration of action of moving object
If a separate control circuit is used to discharge the piezoelectric actuating drive with a delay for extending injection intervals, then the injection interval can be extended without modifying the control device program, but the device complexity increases due to additional components
Solution Approach 1:
The discharging function is segmented into two independent stages: the original discharging circuit controlled by the control device for normal operation, and an additional discharging stage with a delay circuit for extended injection intervals. The changeover switch enables selective activation of the appropriate discharging path, allowing duration extension without interfering with the original control device's discharging sequence.
Solution Approach 2:
The delay circuit is pre-configured with capacitive elements and resistors that automatically generate the required time delay for extended injection intervals. This preliminary setup of the delay mechanism allows the system to extend the injection duration without requiring real-time control program modifications or complex active control algorithms during operation.
3Duration of action of moving object
If the piezoelectric actuating drive is discharged with a delay via an additional discharging stage, then the opening time of the injection nozzle is extended, but the energy management of the piezoelectric element becomes more complex
Solution Approach 1:
The system employs periodic charging cycles through the original charging circuit followed by controlled discharging through either the original discharging circuit or the additional delayed discharging stage. This periodic sequence of charging and discharging allows the piezoelectric element to be reused for multiple injection cycles, with the delay circuit naturally managing energy release timing through its RC time constant without requiring complex energy recovery or management systems.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This solution allows for increased power without modifying the control device's program, ensuring efficient power increase by simulating the piezoelectric actuating drive's discharge through a separate circuit, maintaining input variables and operational consistency.
Implementation Method 1
Injection nozzles for internal combustion engines with piezoelectric actuating drives for actuating the jet needles
Implementation Method 2
a capacitive equivalent load, which is connected to a charging stage and electrically simulates the piezoelectric actuating drive
Data Source
AI summary
An apparatus is described for actuating at least one piezoelectric actuating drive (1) of an injection nozzle for an internal combustion engine, comprising a control device (6) which cyclically actuates a charging circuit and a discharging circuit (2, 3) of the piezoelectric actuating drive (1). In order to enable a power-increasing actuation of the piezoelectric actuating drive (1) it is proposed that a capacitive equivalent load (9), which is connected to a charging stage (13) and electrically simulates the piezoelectric actuating drive (1), and an additional discharging stage (7) for piezoelectric actuating drive (1) and a changeover switch (8) which can be actuated by a control circuit (11) are provided, which switch connects the equivalent load (9) or the piezoelectric actuating drive (1) to the discharging circuit (3) which is controlled via the control device (6), and that after it has been decoupled from the discharging circuit (3) the piezoelectric actuating drive (1) can be discharged with a delay, via the additional discharging stage (7) which can be actuated by the control circuit (11), depending on at least one parameter which changes with the loading of the internal combustion engine.