Variable Valve Timing Oil Pump Flow Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing variable valve timing control systems for internal combustion engines face issues with oil wastage and lubrication shortages during engine startup, leading to potential engine seizure due to inefficient oil filling and communication between advance and retard chambers.
Innovation Solution
A variable valve timing control apparatus that includes a lock pin, oil pressure control valve, oil pump, and oil securing portion, where the oil securing control ensures a minimum oil flow rate during oil filling to prevent lubrication shortages, and the oil pressure control valve manages oil distribution between advance and retard chambers to maintain optimal lubrication.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the communication passage connects the advance chamber to the retard chamber during locked phase, then oil filling efficiency is improved, but oil wastage increases
Solution Approach 1:
The system pre-pressurizes the retard chamber with oil through the communication passage before the oil pressure control valve opens. This preliminary action ensures that when the valve opens, oil is already positioned and pressurized in the retard chamber, eliminating the need for wasteful direct discharge and reducing the time required for effective oil filling.
2Ease of operation
If oil is discharged directly into the drain passage from the retard chamber, then air discharge is improved, but lubricating oil shortage occurs
Solution Approach 1:
The communication passage acts as an intermediary between the advance chamber and the retard chamber, allowing oil to be transferred and pressurized before reaching the drain passage. This intermediary mechanism enables air to be discharged effectively while preventing direct oil wastage, as oil is delivered through a controlled path rather than being directly discharged.
3Productivity
If the oil pressure control valve operates in oil filling mode, then valve timing control is improved, but engine seizure risk increases
Solution Approach 1:
The system performs preliminary oil pressurization in the retard chamber through the communication passage before the oil pressure control valve enters the oil filling mode. This ensures that sufficient lubricating oil is already in place and pressurized, preventing engine seizure even if the valve remains in oil filling mode abnormally.
Solution Approach 2:
The communication passage provides a cushioning effect by pre-positioning and pressurizing oil in the retard chamber before the main oil filling operation. This beforehand cushioning ensures that the lubrication system is already prepared and protected, reducing the risk of engine seizure during abnormal operation.
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
The solution effectively prevents engine seizure by ensuring a sufficient lubricating oil supply and maintaining the engine's lubrication properties, even during abnormal conditions or prolonged oil filling modes.
Implementation Method 1
an oil pump that supplies engine-lubricating oil to the oil pressure control valve
Implementation Method 2
The oil pressure control valve controls pressure of oil supplied to an advance chamber that drives the VCT phase into an advance side, a retard chamber that drives the VCT phase into a retard side
Implementation Method 3
The lock pin locks the VCT phase at a middle lock phase positioned at a middle in a controllable range of the VCT phase
Implementation Method 4
The advance chamber and the retard chamber communicate with each other, when the variable valve timing device controls the oil pressure control valve in a manner that the VCT phase is locked at the middle lock phase by projecting the lock pin
Data Source
AI summary
When a variable valve timing device controls an oil pressure control valve in a manner that a VCT phase is locked at a middle lock phase, an advance chamber and a retard chamber are made to communicate with each other, so that oil is filled into both of the advance chamber and the retard chamber when the oil pressure control valve supplies oil to one of the advance chamber and the retard chamber in an oil filling mode. An oil pump supplies oil to the oil pressure control valve, and is controlled to have an oil flow rate that is equal to or larger than a predetermined value in the oil filling mode.