Passive Mobile Spoiler for Motor Vehicles

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Solution Overview

Problem

Fixed rear spoilers on vehicles do not adapt efficiently to different speed regimes, while movable spoilers improve aerodynamics but increase vehicle weight and energy consumption due to the need for actuating mechanisms.

Innovation Solution

A rear spoiler with a passively mobile second part that adjusts its length based on air flow pressure, using a passive displacement system that includes air pressure transmission, guiding, and return mechanisms, allowing it to extend at high speeds and retract at low speeds without requiring electrical energy.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a movable spoiler system is used to adapt to speed regimes, then aerodynamic efficiency is improved, but vehicle weight increases due to actuating means

Engineering Contradiction:
Improveadaptability to speed regimeVSAvoidvehicle weight
Core Design Contradiction:
Adaptability or versatilityVSWeight of moving object

Solution Approach 1:

The spoiler system uses the kinetic energy of the airflow itself to drive the extension mechanism. The air pressure differential generated by the vehicle's motion through the air creates the force needed to extend the spoiler, eliminating the need for external actuators, motors, or power sources. This self-service approach resolves the contradiction by achieving adaptability without adding weight for actuating means.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The invention employs pneumatic principles by using air pressure differential to drive the spoiler extension. The airflow over the spoiler creates a pressure difference that pushes the movable portion to extend, utilizing the fluid (air) itself as the actuating medium. This resolves the weight contradiction by replacing mechanical/electrical actuators with a pneumatic system that uses the existing airflow.

Inventive Principle:
Principle #29Pneumatics and hydraulics

2Adaptability or versatility

If a movable spoiler system is used to adapt to speed regimes, then aerodynamic efficiency is improved, but energy consumption increases due to actuating means operation

Engineering Contradiction:
Improveadaptability to speed regimeVSAvoidenergy consumption
Core Design Contradiction:
Adaptability or versatilityVSUse of energy by moving object

Solution Approach 1:

The system is self-powered by utilizing the kinetic energy already present in the airflow. The movement of air over the spoiler generates the pressure differential that drives extension, converting the existing kinetic energy into useful work without requiring additional energy input from the vehicle's power system. This eliminates energy consumption for actuation while maintaining adaptability.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The pneumatic mechanism uses the flow energy of the air itself to drive the spoiler extension. The pressure differential created by the airflow provides the driving force, effectively using the fluid's kinetic energy to perform the mechanical action. This approach eliminates the need for electrical or mechanical actuators that would consume additional energy.

Inventive Principle:
Principle #29Pneumatics and hydraulics

3Device complexity

If a fixed spoiler is used, then device complexity is reduced, but aerodynamic efficiency deteriorates at specific speed regimes

Engineering Contradiction:
Improvespoiler system complexityVSAvoidaerodynamic efficiency at different speeds
Core Design Contradiction:
Device complexityVSAdaptability or versatility

Solution Approach 1:

The spoiler transitions from a fixed static structure to a dynamic system that automatically adjusts its configuration based on operating conditions. The movable portion can extend or retract in response to changes in vehicle speed and airflow conditions, allowing the spoiler to optimize its aerodynamic performance across different speed regimes without requiring complex control systems.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The invention changes the geometric parameter (spoiler extension length) automatically in response to varying operating conditions. The movable portion's position is determined by the balance of aerodynamic forces at different speeds, allowing the spoiler to adapt its effective length without external control. This resolves the contradiction by achieving adaptability through passive parameter adjustment rather than active control.

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

The spoiler adapts to speed regimes to enhance aerodynamics by extending at high speeds and retracting at low speeds, improving efficiency without adding weight or energy consumption, as it relies on air pressure for movement.

Implementation Method 1

a passive displacement system able to move the second part according to the flow of air on the upper face of the spoiler

Methodology Applied
Scientific EffectAir flow pressure: Pressure Increase

Implementation Method 2

The position of this type of spoiler is modified by means of mechanized or hydraulic systems making it possible to vary the position of the spoiler according to the speed

Methodology Applied
Scientific EffectAerodynamic force: Drag

Data Source

PatentEP3397541B1Spoiler for motor vehicle provided with a passive mobile element
Publication Date: 2020.02.05 COMPAGNIE PLASTIC OMNIUM SA
  • EP3397541B1 patent drawingFigure 1
  • EP3397541B1 patent drawingFigure 2A~2C
  • EP3397541B1 patent drawingFigure 3A~3C

AI summary

The invention relates to a rear spoiler (10) for a motor vehicle, intended for being arranged in a region of a rear edge of the roof (20) above a rear window (30), said spoiler (10) including a first portion (40) provided with an upper surface (45) substantially aligned with an imaginary extension of an air-flow line (50) of the roof (20). The spoiler is characterised in that it includes a second portion (60), mounted movable relative to the first portion (40), between a retracted position (upstream) and an extended position (downstream), in which the spoiler portion projecting above the rear window (30) is increased, and a passive movement system (70) capable of moving the second portion (60) as a function of the air flow (50) on the upper surface (45) of the spoiler (10).