Injection Valve Needle Closing Time Detection via Voltage Noise Analysis
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Solution Overview
Problem
Existing injection valves face challenges in achieving precise and reliable operation due to variations in engine conditions and wear, leading to inaccuracies in fluid flow rate and quantity, especially when the closing period approaches the activation period, resulting in loss of injection linearity.
Innovation Solution
The method involves determining the closing time of the valve needle by filtering the actuator unit voltage characteristic to isolate noise components, allowing for precise control of the injection duration and quantity through a predetermined activation signal, using an electro-magnetic actuator unit with a coil and core, and optimizing the filtering process to suppress high-frequency signals.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the closing period approaches the activation period, then the injection valve can operate with shorter activation times, but injection linearity is lost and measurement precision deteriorates
Solution Approach 1:
The patent implements feedback by detecting the actual closing time of the valve needle through noise analysis of the actuator voltage characteristic and using this information to compensate for deviations in injection quantity. The system continuously monitors the closing event and adjusts subsequent injections to maintain linearity, allowing short activation periods without losing measurement precision.
Solution Approach 2:
The patent changes the parameter being measured from the raw actuator voltage to the noise component of the voltage characteristic. By filtering and analyzing only the noise portion containing the closing event information, the system can accurately determine closing time even during very short activation periods, thereby maintaining injection linearity while enabling faster operation.
2Adaptability or versatility
If the valve needle closing time varies due to engine conditions and wear, then the injection valve adapts to different operating states, but the precision of fluid dosing deteriorates
Solution Approach 1:
The system uses feedback by continuously monitoring the actuator voltage characteristic during each activation cycle, detecting the actual closing time through noise analysis, and comparing it with expected values. This feedback mechanism allows the system to adapt to varying engine conditions and wear while maintaining precise fluid dosing through real-time compensation.
Solution Approach 2:
The injection valve performs self-diagnosis and self-adjustment by autonomously detecting its own closing time variations through noise analysis of its actuator voltage. The system uses its own operational signals to monitor its state and automatically compensates for deviations, eliminating the need for external calibration equipment or manual adjustments.
3Measurement precision
If noise filtering is applied to determine closing time, then measurement precision of closing time improves, but device complexity increases
Solution Approach 1:
The patent extracts only the noise component from the actuator voltage characteristic for analysis, separating it from the main signal. By focusing exclusively on the noise portion containing the closing event information and applying filtering only to this extracted component, the system achieves high measurement precision while minimizing the complexity of the signal processing required.
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 approach enables precise determination of the valve needle's closing time, ensuring accurate fluid injection control and maintaining injection linearity by accounting for variations in engine conditions and wear, thereby enhancing the reliability and precision of the injection valve's operation.
Implementation Method 1
The electro-magnetic actuator unit comprises a coil and a core... An electrical behaviour of this electro-magnetic circuit can be characterized by an actuator unit voltage
Implementation Method 2
a smoothed actuator unit voltage characteristic is determined by at least filtering the actuator unit voltage characteristic once with a smoothing filter
Data Source
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AI summary
The injection valve (100) comprises a valve needle (20) preventing a fluid flow out of an injection nozzle in a closing position and enabling the fluid flow of the injection nozzle apart from the closing position. Furthermore the injection valve (100) comprises an electro-magnetic actuator unit (36) being designed to actuate the valve needle (20). The actuator unit (36) is activated according to a predetermined activation signal with a given activation period (Ti) for effecting a fluid flow out of the injection nozzle. An actuator unit voltage characteristic (Uc) is captured at least over a period of time during which the valve needle (20) could reach the closing position. A noise part of the actuator unit voltage characteristic (Uc) is determined and a closing time (t_close) representing a time when the valve needle (20) reaches the closing position is determined depending on the noise part of the captured actuator voltage characteristic.