Fender Liner Negative Pressure Venting for Sub Radiator Cooling

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Solution Overview

Problem

Conventional methods for enhancing the cooling performance of a sub radiator mounted in front of a fender liner in a vehicle either compromise aerodynamic performance, increase vehicle weight and manufacturing cost, or fail to ensure adequate cooling due to the trade-offs between air intake, vent hole size, and air resistance.

Innovation Solution

A fender liner structure with a vent hole in the lower wall portion and a negative pressure generation mechanism that promotes air discharge downwards, allowing air to flow through both a first vent hole and a second vent hole, thereby increasing air flow and reducing air resistance without enlarging the sub radiator or air intake port.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If the air intake port and vent hole are made relatively large to increase the amount of air passing through the sub radiator, then the cooling performance is improved, but the aerodynamic performance deteriorates due to increased air resistance applied to the front wheel

Engineering Contradiction:
Improvecooling performanceVSAvoidair resistance
Core Design Contradiction:
TemperatureVSObject-affected harmful factors

Solution Approach 1:

The vent hole is divided into two separate holes: a first vent hole formed in the liner body portion and a second vent hole formed in the lower wall portion. This segmentation allows air to be discharged through multiple paths, reducing the size of each individual vent hole while maintaining adequate total ventilation area for cooling performance.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention adds a vertical dimension to air discharge by forming the second vent hole in the lower wall portion that extends downward. This three-dimensional air discharge approach (combining front-rear direction from first vent hole and upper-lower direction from second vent hole) improves cooling efficiency without requiring larger horizontal vent areas that would increase air resistance.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Temperature

If a separate blower is added to forcibly increase the amount of air passing through the sub radiator, then the cooling performance is improved, but the vehicle body weight and manufacturing cost increase

Engineering Contradiction:
Improvecooling performanceVSAvoidvehicle body weight
Core Design Contradiction:
TemperatureVSWeight of moving object

Solution Approach 1:

The fender liner structure itself is designed to generate negative pressure through its geometry (lower wall portion extending forward and downward, and liner body portion curving over the wheel house). This self-generated negative pressure naturally draws air through the sub radiator without requiring external blowers or fans, eliminating additional weight and cost while maintaining effective cooling.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The invention changes the pressure parameter within the wheel house by creating a negative pressure environment through the specific geometry of the lower wall portion and liner body portion. This pressure change enables natural air flow through the sub radiator, replacing the need for mechanical blowing systems.

Inventive Principle:
Principle #35Parameter changes

3Object-affected harmful factors

If the vent hole size is reduced to decrease air resistance applied to the front wheel, then the aerodynamic performance is improved, but the cooling performance deteriorates due to decreased amount of air passing through the sub radiator

Engineering Contradiction:
Improveair resistanceVSAvoidcooling performance
Core Design Contradiction:
Object-affected harmful factorsVSTemperature

Solution Approach 1:

The vent hole is segmented into two separate holes positioned at different locations and orientations: the first vent hole in the liner body portion for front-rear air discharge and the second vent hole in the lower wall portion for upper-lower air discharge. This segmentation allows each hole to be smaller individually (reducing air resistance) while their combined effect maintains adequate cooling airflow.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Air discharge is extended into the vertical dimension through the second vent hole in the lower wall portion. This multi-directional discharge approach (combining horizontal discharge from first vent hole and vertical discharge from second vent hole) maintains effective cooling with smaller individual hole sizes, thereby reducing air resistance on the front wheel.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

4Temperature

If the sub radiator is made relatively large to increase the amount of air passing through it, then the cooling performance is improved, but the manufacturing cost and vehicle body weight increase

Engineering Contradiction:
Improvecooling performanceVSAvoidmanufacturing cost
Core Design Contradiction:
TemperatureVSEase of manufacture

Solution Approach 1:

The invention changes the pressure and flow distribution parameters within the wheel house by creating negative pressure and establishing multi-directional airflow paths. This allows a smaller sub radiator to achieve the same cooling effect that would otherwise require a larger unit, thereby reducing manufacturing cost and vehicle weight.

Inventive Principle:
Principle #35Parameter changes

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 configuration achieves improved aerodynamic and cooling performance for the sub radiator while maintaining design integrity and minimizing weight and cost increases, ensuring effective air discharge and cooling performance even with smaller vent holes and air intake ports.

Implementation Method 1

The lower wall portion includes a negative pressure generation part configured to generate a negative pressure under the second vent hole

Methodology Applied
Scientific EffectNegative pressure generation: Pressure Gradient

Implementation Method 2

the coolant is cooled by heat exchange with air taken in from an air intake port formed in a front bumper or the like

Methodology Applied
Scientific EffectHeat exchange: Heat Exchanger

Data Source

PatentEP3495250B1Fender liner structure
Publication Date: 2020.07.15 TOYOTA JIDOSHA KK
  • EP3495250B1 patent drawingFigure 1
  • EP3495250B1 patent drawingFigure 2
  • EP3495250B1 patent drawingFigure 3

AI summary

A fender liner structure is disposed in a wheel house (31) of a front wheel (32) of a vehicle. The vehicle includes a sub radiator (40) disposed on a vehicle front side of a fender liner (1). The fender liner structure includes a liner body portion (2) curving in an arch shape to cover the front wheel (32) from above and a lower wall portion (5) extending to the front of the vehicle from a lower end of the liner body portion (2) on the vehicle front side. The liner body portion (2) includes a first vent hole (6) penetrating a vehicle front side part (3) of the liner body portion (2). The lower wall portion (5) includes a second vent hole (7) penetrating a vehicle rear side end portion of the lower wall portion (5) in an upper-lower direction. The lower wall portion (5) includes a negative pressure generation part configured to generate a negative pressure under the second vent hole (7).