Flat Wiper Blade Spoiler Profile for Low Uplift and Drag

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Solution Overview

Problem

Existing flat blade wiper designs face challenges in achieving optimal aerodynamic performance, often compromising between minimizing lift and drag, with sensitivity to extreme attack angles and inefficient airflow engagement.

Innovation Solution

A wiper blade with a spoiler and splines produced in a single piece of flexible material, featuring a deflection surface with a convex leading edge and concave trailing edge profile, optimized to engage air flow smoothly and reduce uplift while maintaining minimal drag, with the trailing edge position enhancing robustness against extreme angles.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the spoiler uses a conventional aerodynamic profile with widened base and narrow tip, then the support surface for incident air flow is optimized, but the uplift is high and sensitive to extreme attack angle variations

Engineering Contradiction:
Improveaerodynamic performance stabilityVSAvoidu uplift force
Core Design Contradiction:
ReliabilityVSForce

Solution Approach 1:

The spoiler profile employs specific curvature characteristics with a convex leading edge and concave trailing edge, replacing conventional flat or simple curved profiles. This curvature optimization enables smoother airflow engagement while reducing uplift force and minimizing sensitivity to attack angle variations.

Inventive Principle:
Principle #14Spheroidality (Curvature)

Solution Approach 2:

The invention modifies key geometric parameters of the spoiler profile, specifically the curvature radius of the leading edge (R1) and trailing edge (R2), along with the relative positions of these edges. By optimizing these parameters, the spoiler achieves reduced uplift while maintaining minimal drag and improved robustness against extreme attack angles.

Inventive Principle:
Principle #35Parameter changes

2Force

If the spoiler profile is optimized for lower uplift, then the aerodynamic performance improves, but the drag increases

Engineering Contradiction:
Improveu uplift forceVSAvoiddrag
Core Design Contradiction:
ForceVSLoss of energy

Solution Approach 1:

The invention optimizes the geometric parameters of the spoiler profile, specifically the curvature radius of the leading edge (R1) and trailing edge (R2), to achieve a balance between uplift reduction and drag minimization. The convex leading edge with radius R1 and concave trailing edge with radius R2 are positioned and dimensioned to maintain smooth airflow while reducing energy loss.

Inventive Principle:
Principle #35Parameter changes

3Ease of manufacture

If the convex leading edge and concave trailing edge are connected with a flat part, then the manufacturing is simplified, but the airflow engagement becomes less smooth

Engineering Contradiction:
Improvemolding simplicityVSAvoidairflow engagement smoothness
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The invention eliminates flat transitions between the convex leading edge and concave trailing edge by implementing continuous curvature throughout the spoiler profile. The convex leading edge with radius R1 transitions smoothly into the concave trailing edge with radius R2, ensuring uninterrupted smooth airflow engagement while remaining manufacturable through conventional molding processes.

Inventive Principle:
Principle #14Spheroidality (Curvature)

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 solution achieves reduced lift and stable aerodynamic performance with minimal drag, improving robustness against extreme angles and ensuring smoother airflow engagement, while using minimal material and maintaining structural integrity.

Implementation Method 1

the spoiler presents a deflection surface covering the first spline at least until a median area of this first spline and at most until the end of this first spline, and the profile of said deflection surface from the first spline to a tip of the spoiler, comprises a leading edge of convex shape followed by a trailing edge of concave shape without flat part between them

Methodology Applied
Scientific EffectAerodynamic flow deflection: Aerofoil

Data Source

PatentEP4480762A1Wiper blade for a motor vehicle
Publication Date: 2024.12.25 VALEO SYST DESSUYAGE SAS
  • EP4480762A1 patent drawingFigure 1~3A
  • EP4480762A1 patent drawingFigure 3B~3D
  • EP4480762A1 patent drawingFigure 3E~4B

AI summary

Wiper blade (1) of a motor vehicle comprising a spoiler (2), a blade (3), and a first and a second splines (4a, 4b), the spoiler (2) and the blade (3) are produced in a single piece of flexible material and are joined with two longitudinal lateral grooves (6) which each receives a respective spline (4a, 4b), wherein the spoiler (2) presents a deflection surface (7) covering the first spline (4a) at least until a median area of this first spline (4a) and at most until the end of this first spline (4a), and the profile of said deflection surface (7) from the first spline (4a) to a tip of the spoiler (2), comprises a leading edge (8) of convex shape followed by a trailing edge (9) of concave shape without flat part between them.