Flow Rate Control Valve Closed Position Learning for Engine Cooling

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Solution Overview

Problem

Variations in the closed position of the flow rate control valve in internal combustion engine cooling systems lead to increased cooling water leakage and reduced control performance, affecting fuel efficiency and emission standards.

Innovation Solution

A closed position learning device that adjusts the flow rate control valve's position based on monitored temperature changes, allowing for accurate control of the cooling water flow rate and temperature, even with variations in the valve's closed position due to production tolerances or wear over time.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a flow rate control valve is used to regulate cooling water flow rate, then cooling water temperature control is improved, but manufacturing precision variations cause the closed position to vary, leading to cooling water leakage and reduced control performance

Engineering Contradiction:
Improvecooling water temperature controlVSAvoidvalve closed position
Core Design Contradiction:
Measurement precisionVSManufacturing precision

Solution Approach 1:

The control device performs preliminary action by learning and storing the actual closed position of the flow rate control valve during an initialization learning phase before normal operation. This pre-acquired position information is then used to compensate for manufacturing variations during actual temperature control operations.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The control device implements feedback by continuously monitoring cooling water temperature and comparing it with target values, then adjusting the flow rate control valve accordingly. The system also incorporates position feedback by detecting the actual valve position and using this information to correct control commands, ensuring accurate temperature control despite manufacturing variations.

Inventive Principle:
Principle #23Feedback

2Reliability

If the flow rate control valve closed position varies due to production tolerance or wear, then valve reliability is reduced, but adding position learning and correction mechanisms increases device complexity

Engineering Contradiction:
Improvevalve closed position accuracyVSAvoidcontrol system
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The control device performs self-service by automatically learning and storing the actual closed position of the flow rate control valve during an initialization phase. This self-acquired position information eliminates the need for external calibration or manual adjustment, maintaining reliability while avoiding excessive complexity.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The control device applies parameter changes by adjusting control commands based on the learned position offset. Instead of physically modifying the valve or adding complex mechanical correction mechanisms, the system changes the control parameter (valve opening command) to compensate for position variations, simplifying the overall device structure.

Inventive Principle:
Principle #35Parameter changes

3Use of energy by moving object

If cooling water leakage into the radiator flow path increases due to incorrect valve position, then fuel efficiency deteriorates, but implementing position learning and correction increases manufacturing cost

Engineering Contradiction:
Improvefuel efficiencyVSAvoidmanufacturing cost
Core Design Contradiction:
Use of energy by moving objectVSEase of manufacture

Solution Approach 1:

The control device replaces mechanical position adjustment mechanisms with electronic control and software-based position learning. Instead of using complex mechanical correction devices or precision-machined components, the system uses sensors, microprocessors, and algorithms to detect and compensate for position variations, reducing manufacturing cost while improving fuel efficiency.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The control device achieves fuel efficiency improvement through parameter changes by adjusting control commands based on learned position offsets. This software-based correction eliminates the need for expensive precision mechanical components or additional hardware, maintaining ease of manufacture while preventing cooling water leakage that would reduce fuel efficiency.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP3130777B1Cooling device for internal combustion engine
Publication Date: 2019.07.31 DENSO CORP
  • EP3130777B1 patent drawingFigure 1
  • EP3130777B1 patent drawingFigure 2
  • EP3130777B1 patent drawingFigure 3

AI summary

Upon a valve rotation angle of a flow rate control valve (15) exceeding a radiator-flow-path closed position during changing of the valve rotation angle of the flow rate control valve (15) in an opening direction of a radiator flow path (16) from a closed state of the radiator flow path (16), a cooling water starts to circulate through the radiator flow path (16), and an outlet water temperature or an inlet water temperature of an engine (11) starts to drop. The radiator-flow-path closed position is learned as a valve rotation angle of the flow rate control valve (15) immediately before the outlet water temperature detected by an outlet water temperature sensor (22) or the inlet water temperature detected by an inlet water temperature sensor (23) starts to drop during changing of the valve rotation angle of the flow rate control valve (15) in the opening direction of the radiator flow path (16) from the closed state of the radiator flow path (16). Consequently, a malfunction caused by a variation in the radiator-flow-path closed position of the flow rate control valve (15) regulating a cooling-water flow rate in the radiator flow path can be restricted.