Engine Valve Lift Control for Condensate Water Freezing Prevention
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Internal combustion engines face full-closure malfunctions due to freezing condensate water accumulating between valve faces and seats, leading to misfires and emission issues when the engine restarts.
Innovation Solution
A control apparatus and method that uses an electronic control unit to determine which cylinders produce more condensate water and adjust the valve lift to zero for those specific valves, preventing condensate water accumulation and freezing by identifying and managing condensate water production differently across cylinders based on port shapes and arrangements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the valve is kept closed to prevent condensate water accumulation, then reliability is improved, but pumping loss increases and engine efficiency deteriorates
Solution Approach 1:
The control unit performs preliminary action by setting the valve lift to zero before condensate water can accumulate and freeze between the valve face and seat. This preventive measure is taken based on prediction of condensate water production conditions, eliminating the need to keep the valve closed continuously and thus reducing pumping loss while ensuring reliability.
Solution Approach 2:
The invention changes the valve lift parameter dynamically based on predicted condensate water conditions. Instead of maintaining a fixed closed state, the valve lift is adjusted to zero only when necessary (when condensate water is predicted), and returned to normal operating values otherwise, optimizing both reliability and energy efficiency.
2Reliability
If the valve lift is adjusted to zero to prevent freezing, then reliability is improved, but engine productivity decreases due to extended stop times
Solution Approach 1:
The control unit applies local quality by identifying specific cylinders where condensate water is predicted to accumulate based on their individual port shapes and arrangements. Only the valves in those specific cylinders have their lift set to zero, while other valves continue normal operation, thus maintaining overall engine productivity while ensuring local reliability.
Solution Approach 2:
The system performs preliminary prediction of condensate water production in each cylinder based on port characteristics and environmental conditions, and takes preventive action (setting valve lift to zero) only for affected cylinders before freezing occurs, rather than shutting down the entire engine.
3Productivity
If the valve remains open during engine stop, then productivity is maintained, but condensate water accumulates and freezes causing malfunctions
Solution Approach 1:
The invention dynamically changes the valve lift parameter based on real-time prediction of condensate water conditions. When condensate water accumulation is predicted, the valve lift parameter is changed to zero to prevent freezing; when no accumulation is predicted, the valve maintains normal open position for productivity.
Solution Approach 2:
The control unit uses feedback from predicted condensate water conditions (based on port characteristics, temperature, humidity, and engine operating history) to adjust valve lift decisions, creating a closed-loop control system that balances productivity and freezing prevention.
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 effectively reduces the likelihood of full-closure malfunctions, ensures proper valve operation, and prolongs engine stop times by minimizing pumping loss, thereby enhancing engine reliability and efficiency.
Implementation Method 1
amounts of condensate water produced in the ports or flowing into the ports are different from one another among the cylinders
Implementation Method 2
condensate water accumulates between valve faces and valve seats of the intake valve and the exhaust valve due to the effect of a surface tension of condensate water
Implementation Method 3
When these valves are halfway open, condensate water accumulates between valve faces and valve seats... In the case where this condensate water freezes, when the internal combustion engine is started next time, a full-closure malfunction may occur
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A control apparatus for an internal combustion engine (2) includes an electronic control unit (100) that is configured to perform an operation of making a lift amount of a specific valve corresponding to one of either intake ports (58) or exhaust ports (60) for a specific cylinder in which an amount of condensate water produced in the port or flowing into the port is larger than in the other cylinders when the engine is stopped, in a case where production of condensate water in the ports or inflow of condensate water into the ports is predicted.