Engine Oil Supply System with Pressure-Operated Piston Cooling Valves
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Solution Overview
Problem
Current oil supply systems for reciprocating piston internal engines do not adjust oil flow based on engine operating conditions, leading to oversupply and reduced fuel economy, particularly due to overcooling of pistons at low engine loads.
Innovation Solution
An oil supply system that adjusts oil pressure inversely with engine speed using a solenoid valve and pressure-operated valves to selectively route oil to piston cooling jets, allowing for low and high pressure modes based on engine speed and load, ensuring optimal oil supply matching engine conditions and maintaining cooling functionality even in solenoid valve degradation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If oil is supplied continuously to piston cooling jets regardless of engine operating conditions, then piston cooling function is maintained, but fuel economy deteriorates due to overcooling at low load and unnecessary power consumption
Solution Approach 1:
The oil supply system dynamically adjusts the supply pressure based on engine operating conditions (engine speed and load). The control unit receives signals from engine speed and load sensors, then modulates the oil pump output pressure accordingly. At low engine load, the system reduces or stops oil supply to piston cooling jets, preventing overcooling and reducing energy consumption. At high engine load, the system increases oil supply pressure to ensure adequate piston cooling, thus resolving the contradiction between maintaining cooling reliability and improving fuel economy.
2Use of energy by moving object
If oil supply pressure is reduced at low engine speed to improve fuel economy, then fuel consumption decreases, but oil pressure may become insufficient for proper lubrication
Solution Approach 1:
The system applies different oil supply pressures to different destinations based on local needs. The control unit selectively directs oil flow: to piston cooling jets when cooling is required (high load conditions), and to lubrication points when lubrication is prioritized (low load conditions). This localized quality control ensures that each component receives the appropriate oil pressure for its specific function, maintaining lubrication reliability while improving fuel economy through selective pressure reduction at cooling jets during low-load operation.
3Ease of operation
If a solenoid valve is used to control oil pressure modulation, then precise oil supply control is achieved, but system complexity increases
Solution Approach 1:
The system employs a solenoid valve actuated by an electromagnetic coil to control oil pressure modulation. The solenoid valve responds to electrical signals from the control unit, which receives inputs from engine speed and load sensors. This hydraulic control mechanism provides precise and responsive oil supply pressure adjustment based on real-time engine operating conditions. While the solenoid valve adds some complexity, it enables accurate dynamic control that significantly improves fuel economy and piston cooling efficiency, justifying the added complexity through substantial performance gains.
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 system reduces fuel usage by matching oil supply to engine operating conditions, preventing overcooling and ensuring continuous piston cooling, thereby enhancing fuel economy and reliability.
Implementation Method 1
adjusting a solenoid valve hydraulically coupled with an oil pump
Implementation Method 2
selectively routing oil through an oil galley to a piston cooling jet via a pressure-operated valve responsive to the adjusted oil pressure
Implementation Method 3
a pump to supply oil at pressure from the reservoir to components including at least one piston cooling jet requiring a supply of oil
Data Source
AI summary
An oil supply system for a reciprocating piston internal combustion engine is disclosed in which the supply of oil to piston cooling jets is controlled by pressure operated valves designed to open at a pre-defined valve opening pressure. The pressure of oil supplied by a pump is controlled to be below this pre-defined valve opening pressure during operation of the engine in which piston cooling is not required, and the pressure of oil is controlled to above the pre-defined valve opening pressure when piston cooling is required. The control of the pump is by an electronic control unit based upon a combination of engine speed and engine load.