Wiper Arm Tilting Arrangement for Curved Windshield Contact

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Solution Overview

Problem

Conventional wiper systems struggle to maintain effective contact with highly curved windshields, leading to intermittent wiping performance due to varying attack angles during the wiping motion.

Innovation Solution

A wiper system incorporating a spring arrangement and tilting mechanism, combined with a constant-velocity joint and ball-and-race groove configuration, allows the wiper arm to maintain contact and adjust its inclination relative to the windshield curvature, ensuring consistent wiping performance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a conventional wiper system is used with a highly curved windscreen, then the wiper blade cannot maintain a normal attack angle throughout the wiping motion, but the structure remains simple

Engineering Contradiction:
Improvewiping performance consistencyVSAvoidwiper system structure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The wiper arm is designed with a tilting arrangement that allows it to dynamically adjust its inclination angle relative to the windscreen surface during the wiping motion. This dynamic adjustment enables the wiper blade to maintain a substantially constant normal attack angle throughout the complete wiping stroke, even on highly curved windscreens, thereby resolving the technical contradiction between wiping performance consistency and structural simplicity.

Inventive Principle:
Principle #15Dynamics

2Reliability

If the wiper arm inclination is varied to match windscreen curvature, then contact stability may be compromised, but wiping effectiveness on curved surfaces is improved

Engineering Contradiction:
Improvecontact stabilityVSAvoidwindscreen curvature adaptation
Core Design Contradiction:
ReliabilityVSAdaptability or versatility

Solution Approach 1:

The tilting arrangement enables the wiper arm to dynamically vary its inclination angle during the wiping motion, allowing adaptation to different windscreen curvatures while maintaining stable contact through the spring arrangement's resilient pressing force.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The spring arrangement applies a resilient pressing force that compensates for variations in contact pressure caused by changing inclination angles. This parameter change in applied force ensures stable and reliable contact between the wiper blade and the windscreen surface throughout the wiping motion, even as the arm tilts to match curvature.

Inventive Principle:
Principle #35Parameter changes

3Reliability

If a spring arrangement is added to maintain contact pressure, then contact stability is improved, but device complexity increases

Engineering Contradiction:
Improvecontact pressure consistencyVSAvoidwiper system components
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The spring arrangement introduces a resilient pressing force that dynamically adjusts contact pressure to maintain consistent contact between the wiper blade and windscreen. This parameter change in applied force compensates for variations caused by tilting motion and windscreen curvature, improving contact pressure consistency.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The spring arrangement is integrated into the existing wiper arm structure, combining the contact pressure maintenance function with the tilting mechanism. This merging approach minimizes additional complexity by utilizing the existing structural elements while adding the spring component for resilient pressing.

Inventive Principle:
Principle #5Merging (Combining)

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 stabilizes the wiper arm throughout its rotation and tilting motion, providing a consistent wiping result even on highly curved windshields by resiliently pressing the wiper arm against the windshield and allowing for efficient force transfer and controlled tilting.

Implementation Method 1

a spring arrangement configured to resiliently press the wiper arm against the connecting arrangement in the axial direction

Methodology Applied
Scientific EffectSpring: Spring

Implementation Method 2

said connecting arrangement forms part of a constant-velocity joint, which may also be referred to as a CV joint. A CV joint allows a drive shaft to transmit power through a variable angle at a constant rotational speed

Methodology Applied
Scientific EffectConstant-velocity joint:

Implementation Method 3

the connecting arrangement comprises at least one ball configured to mate with said race groove and to transmit the rotating force of the shaft to the wiper arm via engagement with the race groove wall

Methodology Applied
Scientific EffectBall bearing: Ball Bearing

Data Source

PatentEP4048559B1A wiper system and a vehicle comprising such a wiper system
Publication Date: 2023.02.15 VOLVO TRUCK CORP
  • EP4048559B1 patent drawingFigure 1
  • EP4048559B1 patent drawingFigure 2
  • EP4048559B1 patent drawingFigure 3a

AI summary

A wiper system (10), comprising a wiper arm (12)having a geometrical axis of rotation (x), a connecting arrangement (14) configured to connect the wiper arm to a motor-driven rotating shaft (100), wherein the connecting arrangement is configured to transfer the rotating motion of the shaft into a rotating motion of the wiper arm about said geometrical axis of rotation, a spring arrangement (24) configured to resiliently press the wiper arm against the connecting arrangement in the axial direction, and a tilting arrangement (30) configured to vary the inclination of the pressed wiper arm relative to said geometrical axis of rotation based on the rotational position of the wiper arm about said geometrical axis of rotation. There is also provided a vehicle comprising such a wiper arm system.