High Pressure Pump Spill Valve Timing Correction
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Solution Overview
Problem
The existing methods for correcting spill valve timing errors in high pressure fuel pumps of internal combustion engines often require angular position sensors, which can be costly and increase system complexity, and may not effectively synchronize spill valve actuation with pump piston movement.
Innovation Solution
A method that adjusts the duty cycle of the high pressure pump based on fuel rail pressure readings to correct spill valve timing errors, allowing for on-board synchronization without additional sensors, by determining an offset in the zero flow function to synchronize spill valve timing with the compression stroke of the pump piston.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If angular position sensors are used to correct spill valve timing errors, then timing accuracy is improved, but system complexity and cost increase
Solution Approach 1:
The patent extracts the timing correction capability from the sensor-based system and implements it using only existing fuel rail pressure sensor data. By analyzing the relationship between pump duty cycle and fuel rail pressure, the system determines a zero flow function that reveals timing offsets without requiring additional angular position sensors.
Solution Approach 2:
The existing fuel rail pressure sensor serves dual purposes: monitoring fuel pressure for injection control and detecting spill valve timing errors. The system self-diagnoses timing offsets by analyzing pressure responses to duty cycle changes, eliminating the need for separate timing detection sensors.
2Measurement precision
If additional sensors are added to monitor spill valve timing, then timing synchronization is improved, but system cost increases
Solution Approach 1:
The fuel rail pressure sensor is made multi-functional by using it both for its original pressure monitoring purpose and for detecting spill valve timing errors. The control unit analyzes pressure data to determine timing offsets, allowing one sensor to perform multiple measurement functions.
Solution Approach 2:
The system uses its existing pressure sensing capability to self-diagnose timing synchronization issues. By commanding duty cycle changes and measuring the resulting pressure responses, the system automatically detects timing offsets without external sensing equipment.
3Measurement precision
If spill valve timing is corrected using sensor-based methods, then timing accuracy is improved, but control system complexity increases
Solution Approach 1:
The system implements feedback by commanding duty cycle changes, measuring the resulting fuel rail pressure responses, and using this feedback to determine timing offsets. The control unit continuously monitors the relationship between pump operation and pressure changes to detect and correct timing synchronization errors.
Solution Approach 2:
The patent replaces mechanical sensor-based timing detection with an analytical approach using pressure data processing. Instead of mechanical or electrical sensors directly measuring valve position, the system infers timing information from fuel rail pressure responses to controlled duty cycle variations.
Data Source
AI summary
Methods are provided for correct spill valve timing of a high pressure pump coupled to the direct injection system of an internal combustion engine. A method is needed to monitor and adjust spill valve timing on-board the vehicle, where spill valve timing error may result from sensors error and/or time between command signal and actuation response of the spill valve. To self-correct spill valve timing error on-board a vehicle, methods are proposed that involve monitoring and recording fuel rail pressures, high pressure pump duty cycles, and fractional liquid volume pumped values in order to find zero flow relationships.