Vehicle Window Lip Gap Tapering for Wind Noise Reduction

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Solution Overview

Problem

Existing vehicle window structures with small windows, like opera windows, suffer from wind noise due to gaps between moldings and door sashes, which allow traveling wind to enter and generate noise.

Innovation Solution

A vehicle window section structure featuring a lip on the small window's periphery and a door mirror mount with a gap that tapers inward, reducing wind speed and increasing pressure, thereby minimizing noise through Bernoulli's principle.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If a molding is arranged along the outer periphery of the small window, then the window structure is completed and assembled, but a gap is formed between the molding and the door sash that allows traveling wind to enter and generate wind noise

Engineering Contradiction:
Improvewindow structure assemblyVSAvoidwind noise
Core Design Contradiction:
Ease of manufactureVSObject-affected harmful factors

Solution Approach 1:

A wind noise reducing member is introduced as an intermediary component between the molding and the door sash. This member fills the gap that would otherwise allow traveling wind to enter, thereby eliminating wind noise while maintaining the existing molding and sash structures without requiring redesign of the entire window assembly

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The wind noise reducing member is configured as a thin, flexible component that can be positioned within the gap between the molding and door sash. This thin-film structure effectively blocks wind entry while maintaining ease of installation and not interfering with the overall window assembly structure

Inventive Principle:
Principle #30Flexible shells and thin films

2Ease of manufacture

If the gap between the lip and door mirror mount is uniform, then the structure is simple to manufacture, but traveling wind maintains high flow speed and generates wind noise

Engineering Contradiction:
Improvegap structureVSAvoidwind noise
Core Design Contradiction:
Ease of manufactureVSObject-affected harmful factors

Solution Approach 1:

The gap between the lip and door mirror mount is designed with non-uniform characteristics - specifically, the gap width varies along the length of the gap. This local variation in gap geometry creates regions of different flow resistance, causing traveling wind to decelerate as it passes through, thereby reducing wind noise generation at critical locations

Inventive Principle:
Principle #3Local quality

3Object-affected harmful factors

If the gap width is increased to reduce wind noise, then wind flow is reduced, but the structural integrity and appearance are compromised

Engineering Contradiction:
Improvewind noiseVSAvoidstructural integrity
Core Design Contradiction:
Object-affected harmful factorsVSStrength

Solution Approach 1:

The wind noise reducing member acts as an intermediary that allows for effective wind noise reduction without requiring large gap dimensions. By placing this blocking member within the existing gap, the actual gap width can remain small (preserving structural integrity and appearance) while the member itself prevents wind flow that would generate noise

Inventive Principle:
Principle #24Intermediary (Mediator)

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 efficiently reduces wind noise by gradually decreasing wind speed and increasing pressure within the gap, demonstrated by lower noise levels and improved articulation index compared to structures without this feature.

Implementation Method 1

the flow speed of the traveling wind gradually decreases and the pressure thereof increases. Accordingly, it is possible to efficiently reduce the wind noise by the traveling wind

Methodology Applied
Scientific EffectBernoulli's principle: Bernoulli Effect

Data Source

PatentEP2578425B1Vehicle window section structure
Publication Date: 2017.07.05 NISSAN MOTOR CO LTD
  • EP2578425B1 patent drawingFigure 1
  • EP2578425B1 patent drawingFigure 2
  • EP2578425B1 patent drawingFigure 3

AI summary

Provided is a vehicle window section structure in which in a state where an openable and closable front door is closed, a gap (63) extending inward in a vehicle width direction is formed between a small window (9) provided on a vehicle body side and a mount body (25) of a door mirror mount provided to the front door. A peripheral member (11) is provided on the outer periphery of the small window (9). A lip (50) extending along the vehicle width direction is provided to the peripheral member (11). Distance between the lip (50) and the mount body (25) facing the lip (50) is larger toward an outer end in the vehicle width direction and smaller toward an inner end in the vehicle width direction.