Lubricant Pressure Build-Up Evaluation During Engine Start-Up
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Solution Overview
Problem
Existing methods for evaluating lubricant pressure during an engine starting process are not accurate enough to determine the quality of lubrication for friction components, particularly in the short period of pressure build-up, which can lead to wear and damage in vehicles with automatic stop-start systems.
Innovation Solution
A method that uses a pressure determination device and a path determination device to continuously monitor lubricant pressure and relative travel between friction components during engine start-up, generating an evaluation value from the sum of pressure times and relative displacement values to assess lubricant pressure build-up, which can be stored for later evaluation or immediate functional testing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a simple pressure limit comparison method is used to monitor lubricant pressure, then the device complexity is low, but the measurement precision is insufficient to evaluate lubrication quality during the short engine start-up period
Solution Approach 1:
The invention changes the evaluation parameter from a simple binary pressure limit comparison to a continuous evaluation value that integrates pressure magnitude and duration. This allows precise assessment of lubrication quality during the short start-up period by accumulating pressure-time products, transforming the evaluation from qualitative to quantitative without requiring complex additional hardware
Solution Approach 2:
The invention introduces an intermediary evaluation value that mediates between the raw pressure signal and the final lubrication quality assessment. This evaluation value accumulates pressure-time products and provides a comprehensive measure of lubrication quality, avoiding the need for direct complex measurements while maintaining high precision
2Reliability
If an electrically driven lubricant pump is installed to ensure sufficient lubricant pressure before engine start, then the reliability of lubrication is improved, but the device complexity and cost increase
Solution Approach 1:
The invention replaces the mechanical solution of an electrically driven pump with a measurement and evaluation system. Instead of adding complex mechanical components to force lubricant pressure buildup, the system uses sensors and evaluation algorithms to monitor and assess the natural pressure buildup process, achieving reliability through information processing rather than mechanical intervention
3Reliability
If the lubricant pump is mechanically decoupled from the engine crankshaft to enable pre-lubrication, then the lubrication quality during start-up is improved, but the ease of operation and system simplicity deteriorate
Solution Approach 1:
The invention implements a feedback system that continuously monitors lubricant pressure during start-up and evaluates whether sufficient lubrication has been achieved. This feedback mechanism provides real-time information about lubrication quality, enabling automated decision-making about engine start permission without requiring complex mechanical pre-lubrication systems
Data Source
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AI summary
The invention relates to a method for evaluating the lubrication of friction components rubbing against each other of a device (3) that can be lubricated by means of a lubricant circuit (5), in particular an internal combustion engine or an automatic transmission, wherein a lubricant pump (9) of the lubricant circuit (5) can be driven by means of a drive motor forming the device or by means of a drive motor (3) driving the device.According to the invention, a pressure detection device (19) is provided by means of which the lubricant pressure at at least one defined area of the lubricant circuit (5) is continuously determined during an engine start-up process, wherein a displacement detection device is also provided by means of which, at several pressure times at which the lubricant pressure determined by means of the pressure detection device exceeds a defined pressure limit value (p1, p2, p3), the relative displacement between the friction components since the beginning of the engine start-up process is determined and/or estimated, and wherein an evaluation device (17) is provided by means of which an evaluation value is determined from the sum of the relative displacement values (ϕ1, ϕ2, ϕ3) determined at the pressure times, which evaluates the lubricant pressure build-up during the engine start-up process.