Vehicle Thermal Circuit Maintenance With Solenoid Valve Reconfiguration

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Solution Overview

Problem

Existing cooling systems in motor vehicles, particularly electric vehicles, face complexity in maintenance due to the need for adapting coolant flow rates to varying operating conditions and require efficient methods for coolant replacement.

Innovation Solution

A method and device for maintaining a thermal system in motor vehicles that simplifies maintenance by implementing a first circulation of heat transfer fluid through a series circuit using solenoid valves in a resting state, followed by draining, filling, and evacuating gas bubbles, facilitated by a single degassing jar and vacuum pump system.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If multiple solenoid valves are used to control coolant flow rates for different operating conditions, then the adaptability of the thermal system is improved, but the device complexity increases

Engineering Contradiction:
Improvecoolant flow rate adaptationVSAvoidnumber of solenoid valves
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent applies multi-functionality by designing a thermal system where a limited number of solenoid valves (at most three) perform multiple functions by combining different circulation paths. The valves control both the main circulation circuit and the bypass circuit, allowing the system to adapt to different operating conditions (cabin heating, engine warming, coolant replacement) without requiring a separate valve for each function.

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Adaptability or versatility

If a complex cooling circuit is designed to adapt to varying operating conditions, then the thermal management capability is improved, but the ease of maintenance deteriorates

Engineering Contradiction:
Improvethermal management capabilityVSAvoidease of maintenance
Core Design Contradiction:
Adaptability or versatilityVSEase of operation

Solution Approach 1:

The patent applies segmentation by dividing the thermal system into distinct functional assemblies: a first assembly with thermal management components (electric motor, battery, thermal resistor, cooler, radiator), a second assembly with conduits for heat transfer fluid, and a third assembly with solenoid valves. This segmentation allows for simplified maintenance procedures where each assembly can be independently accessed and serviced, particularly facilitating coolant replacement by isolating specific circuit portions.

Inventive Principle:
Principle #1Segmentation

3Ease of operation

If coolant replacement procedures are simplified, then the ease of maintenance is improved, but the reliability of the maintenance process may worsen

Engineering Contradiction:
Improveease of maintenanceVSAvoidmaintenance process reliability
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The patent applies preliminary action by pre-configuring the solenoid valves to specific positions before coolant replacement. The method includes a first step of positioning solenoid valves to establish a first circulation path that isolates portions of the cooling circuit, followed by draining, filling, and degassing operations. This preliminary valve positioning ensures that coolant can be replaced in a controlled manner without contaminating the entire system, maintaining reliability while simplifying the overall maintenance procedure.

Inventive Principle:
Principle #10Preliminary action

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 reduces maintenance time and costs by optimizing coolant replacement and degassing processes, enhancing the efficiency and reliability of thermal management systems.

Implementation Method 1

a tool equipped with a vacuum pump capable of sucking air present in the conduits of the second assembly

Methodology Applied
Scientific EffectVacuum: Vacuum

Implementation Method 2

the thermal system includes at least one pump and the fourth step of evacuating gas bubbles contained in the thermal system includes circulating the new heat transfer fluid by actuation of at least one pump

Methodology Applied
Scientific EffectPump: Pump

Implementation Method 3

a third assembly comprising at least one solenoid valve, and in particular at most three solenoid valves, connected to conduits of the second assembly

Methodology Applied
Scientific EffectValve: Valve

Data Source

PatentEP4446150B1Device for maintaining a thermal system for a motor vehicle
Publication Date: 2025.11.05 RENAULT SA
  • EP4446150B1 patent drawingFigure 1
  • EP4446150B1 patent drawingFigure 2~3
  • EP4446150B1 patent drawingFigure 4~5

AI summary

Maintenance method for a thermal system for a motor vehicle comprising • a first assembly comprising components, • a second assembly comprising conduits for a heat transfer fluid, connecting the components of the first assembly, and • a third assembly comprising at least one solenoid valve, the thermal system putting a first circuit in series connecting all the components of the first assembly when the solenoid valve(s) of the third assembly are all in a rest state, the maintenance method comprising - a first step of implementing the first circulation, then - a second step of draining a heat transfer fluid circulating in the second set of conduits, then - a third step of filling the second set of conduits with a new heat transfer fluid, then - a fourth step of evacuating gas bubbles contained in the second set of conduits.