Vehicle Cooling System Pilot Line Feedback Control

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Solution Overview

Problem

Conventional vehicle cooling systems experience slow feedback and temperature cycling due to the distance between the cooler and the thermostat, leading to frequent exposure to large temperature changes and reduced system reactivity, especially when dealing with rapid temperature changes associated with components like hydraulic retarders.

Innovation Solution

A cooling system design that utilizes a pilot line to sense the temperature of the cooling fluid at positions immediately downstream of components that can rapidly change its temperature, allowing for rapid regulation by the thermostat, and incorporates a three-way valve and control unit to manage cooling fluid flow based on the activation status and cooling power requirements of components like hydraulic retarders.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If the thermostat is positioned at a relatively large distance from the cooler in the cooling system, then the cooling system structure is simpler, but the feedback time is delayed and temperature cycling occurs

Engineering Contradiction:
Improvecooling system structureVSAvoidfeedback time
Core Design Contradiction:
Device complexityVSLoss of time

Solution Approach 1:

The patent introduces a pilot line that branches off from the main cooling system, creating a separate sensing pathway. This segmentation allows the temperature sensor to be positioned close to the cooler for rapid feedback while the main thermostat can remain at a conventional distance, resolving the contradiction between structural simplicity and fast response time.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The pilot line acts as an intermediary element that transfers cooling fluid from near the cooler to the temperature sensor. This intermediary pathway enables rapid temperature sensing without requiring the main thermostat to be repositioned, thus maintaining system simplicity while achieving fast feedback.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Ease of operation

If the temperature sensor is positioned far from components that rapidly change temperature, then the cooling system installation is easier, but the system cannot detect rapid temperature changes promptly

Engineering Contradiction:
Improveinstallation easeVSAvoidtemperature detection speed
Core Design Contradiction:
Ease of operationVSSpeed

Solution Approach 1:

By segmenting the cooling system into a main flow path and a separate pilot line, the patent enables the temperature sensor to be positioned optimally near rapidly heating components without complicating the overall system installation. The pilot line carries a portion of the cooling fluid to the sensor location.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The pilot line creates a copy of the cooling fluid flow that can be routed to the temperature sensor independently. This copying mechanism allows the sensor to monitor temperature changes at the optimal location without disrupting the main cooling system's straightforward installation.

Inventive Principle:
Principle #26Copying

3Reliability

If the thermostat switches frequently between open and closed conditions due to slow feedback, then the cooling system covers temperature variations, but the cooler is exposed to large temperature changes reducing its lifetime

Engineering Contradiction:
Improvetemperature regulationVSAvoidcooler lifetime
Core Design Contradiction:
ReliabilityVSDuration of action of stationary object

Solution Approach 1:

The patent implements rapid feedback by positioning the temperature sensor in the pilot line near the cooler, allowing the thermostat to detect temperature changes immediately. This rapid feedback enables smoother thermostat switching and reduces the frequency and magnitude of temperature cycles, thereby extending the cooler's operational life while maintaining reliable temperature regulation.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The pilot line provides preliminary temperature information to the thermostat before significant temperature changes occur in the main cooling system. This preliminary action allows the thermostat to anticipate and respond to temperature variations more gradually, reducing thermal shock to the cooler.

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 design enables rapid and effective cooling of the cooling fluid, reducing temperature cycling and extending the lifespan of cooling system components by providing immediate feedback and optimal cooling during component activation, particularly in heavy vehicles with hydraulic retarders.

Implementation Method 1

The cooling system comprises a thermostat with a temperature sensor that senses the temperature of the cooling fluid

Methodology Applied
Scientific EffectTemperature sensing:

Implementation Method 2

The cooler is a component of the cooling system that can change the temperature of the cooling fluid rapidly

Methodology Applied
Scientific EffectHeat exchange: Heat Exchanger

Implementation Method 3

The combustion engine is a third component in the cooling system that influences the temperature of the cooling fluid

Methodology Applied
Scientific EffectThermal energy conversion:

Data Source

PatentEP2935822B1Cooling system in a vehicle
Publication Date: 2018.01.10 SCANIA CV AB
  • EP2935822B1 patent drawingFigure 1~2
  • EP2935822B1 patent drawingFigure 3

AI summary

The present invention concerns a cooling system in a vehicle for the cooling of a combustion engine (1) and a component (6) that can be activated intermittently. The cooling system comprises a thermostat (9) with a sensor (15) that is adapted to sense the temperature of the cooling fluid in a pilot line (16). The pilot line (6) comprises a first inlet section (16a) that receives cooling fluid from an inlet line to the combustion engine (1) and a second inlet section (16b) that receives cooling fluid from an outlet line (8) of the said component (6). The pilot line (16) comprises a valve arrangement (16c, 16d, 17, 20) that in a first condition leads cooling fluid from the first inlet section (16a) to the pilot line (16) and in a second condition leads cooling fluid from the second inlet section (16b) to the pilot line (16), and control means (16i, 16e, 16g, 18) that is adapted to set the valve arrangement into the first condition when the said component requires a lower cooling power than a threshold value or into the second condition when the said component (6) requires a higher cooling power than the threshold value.