Oil Cooler Bypass Control for Low-Temperature Oil Pressure

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing oil pressure control systems fail to maintain proper oil pressure when the oil temperature is low, leading to reduced durability and reliability of engine components.

Innovation Solution

An oil pressure control apparatus comprising an oil cooler, a bypass oilway, an oil-cooler bypassing valve, an oil pressure sensor, and a valve control section that adjusts the oil flow to minimize the difference between the measured and target oil pressures based on engine speed and fuel injection quantity, ensuring proper oil pressure even at low temperatures.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stress or pressure

If the engine oil is cooled through the oil cooler to raise oil pressure, then the oil pressure increases, but the fuel efficiency decreases due to unnecessary cooling at low temperatures

Engineering Contradiction:
Improveoil pressureVSAvoidfuel efficiency
Core Design Contradiction:
Stress or pressureVSUse of energy by moving object

Solution Approach 1:

The bypass valve dynamically switches between opening and closing states based on real-time monitoring of oil temperature and oil pressure, allowing the system to adapt to varying operating conditions. When oil temperature is low and pressure is sufficient, the valve remains closed to prevent unnecessary cooling. When pressure drops below threshold, the valve opens to allow cooling, thus dynamically optimizing both pressure maintenance and fuel efficiency.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The control system monitors changes in oil temperature and oil pressure parameters, using these parameter variations to determine valve operation. By detecting when oil pressure falls below a predetermined threshold or when temperature drops below a threshold, the system adjusts the bypass valve state accordingly, changing the cooling parameter to maintain optimal oil pressure without wasteful energy consumption.

Inventive Principle:
Principle #35Parameter changes

2Stress or pressure

If the oil cooler continuously cools the engine oil to maintain proper oil pressure, then the oil pressure is maintained, but the engine durability is reduced due to excessive cooling at low temperatures

Engineering Contradiction:
Improveoil pressureVSAvoidengine durability
Core Design Contradiction:
Stress or pressureVSReliability

Solution Approach 1:

The bypass valve dynamically adjusts its state based on real-time oil temperature and pressure conditions, preventing excessive cooling when oil temperature is already low. This dynamic control ensures oil pressure is maintained only when necessary, preserving engine component integrity and durability while avoiding the harmful effects of unnecessary cooling.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system uses feedback from oil temperature sensors and oil pressure sensors to continuously monitor system state and adjust bypass valve operation. When oil pressure is sufficient or temperature is low, the feedback signal keeps the valve closed, preventing excessive cooling. When pressure drops, the feedback triggers valve opening to restore pressure, thus protecting engine durability through intelligent feedback control.

Inventive Principle:
Principle #23Feedback

3Use of energy by moving object

If the bypass valve opens to prevent cooling, then fuel efficiency improves, but oil pressure drops below proper levels when cooling is actually needed

Engineering Contradiction:
Improvefuel efficiencyVSAvoidoil pressure
Core Design Contradiction:
Use of energy by moving objectVSStress or pressure

Solution Approach 1:

The control system monitors oil pressure and temperature parameters to determine appropriate bypass valve operation. When oil pressure remains above the predetermined threshold or oil temperature is below the threshold, the valve stays closed to maintain pressure. When pressure drops below the threshold indicating insufficient cooling, the valve opens to allow cooling, thus using parameter-based control to balance pressure maintenance with fuel efficiency.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The feedback mechanism continuously monitors oil pressure levels and adjusts bypass valve state accordingly. When pressure falls below the predetermined threshold, the feedback signal triggers valve opening to restore pressure through cooling. When pressure is adequate, feedback keeps the valve closed to maintain fuel efficiency, ensuring pressure is maintained only when actually needed.

Inventive Principle:
Principle #23Feedback

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 apparatus effectively maintains proper oil pressure at low temperatures, enhancing engine durability and reliability while preventing unnecessary oil temperature lowering, which improves fuel efficiency by avoiding increased friction between engine components.

Implementation Method 1

an oil cooler that cools engine oil that circulates in a hydraulic circuit of an engine

Methodology Applied
Scientific EffectHeat transfer: Heat Exchanger

Implementation Method 2

an oil pressure sensor that measures a first oil pressure that is an oil pressure of the engine oil

Methodology Applied
Scientific EffectPressure detection: Pressure Gradient

Data Source

PatentEP3546710B1Oil pressure control device
Publication Date: 2023.03.29 ISUZU MOTORS LTD
  • EP3546710B1 patent drawingFigure 1
  • EP3546710B1 patent drawingFigure 2
  • EP3546710B1 patent drawingFigure 3

AI summary

This oil pressure control device is provided with: an oil cooler which cools engine oil circulating through a hydraulic circuit of an engine; a bypass oil passage which bypasses the oil cooler; an oil cooler bypass valve by means of which an engine oil flow passage is switched between the oil cooler and the bypass oil passage; an oil pressure sensor which measures a first oil pressure, which is the oil pressure of engine oil; and a valve control unit which controls opening and closing of the oil cooler bypass valve to reduce the magnitude of a difference between the first oil pressure and a second oil pressure, which is a target oil pressure determined on the basis of the rotational speed of the engine and a fuel injection quantity.