Motor Vehicle Air Duct Corner Latching for Low Flow Resistance

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Solution Overview

Problem

Conventional air duct systems produced by blow molding or 2-plate thermoforming suffer from thin walls, leading to large locking elements that cause flow resistance, turbulence, pressure losses, and leakage due to inadequate tightness in the connection area.

Innovation Solution

The air duct system features polygonal connecting sections with latching elements and counter-latching elements arranged on the corners, allowing for a smaller design while maintaining connection strength, and an insertion bevel with varying gradients to facilitate assembly without crushing the side walls, ensuring a secure and leak-free connection.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If large locking elements are used in the connecting section, then connection strength is improved, but flow resistance and turbulence increase

Engineering Contradiction:
Improveconnection strengthVSAvoidflow resistance
Core Design Contradiction:
StrengthVSLoss of energy

Solution Approach 1:

The patent applies local quality by concentrating the latching connection exclusively at the corner areas of the connecting sections. The corners are designed with increased inherent rigidity to provide adequate connection strength, while the side walls maintain their original thin-walled structure to minimize flow resistance and turbulence in the air flow path.

Inventive Principle:
Principle #3Local quality

2Strength

If large locking elements are used in the connecting section, then connection strength is improved, but the side walls are crushed and leaks occur

Engineering Contradiction:
Improveconnection strengthVSAvoidconnection tightness
Core Design Contradiction:
StrengthVSReliability

Solution Approach 1:

The patent differentiates between local requirements for connection strength at corners versus maintaining wall integrity for sealing. By placing latching elements only at corners with naturally higher rigidity, the design avoids applying concentrated forces that would crush the thinner side walls, thus preventing leaks while achieving adequate connection strength.

Inventive Principle:
Principle #3Local quality

3Ease of manufacture

If thin-walled air ducts are used, then manufacturing simplicity is improved, but connection tightness deteriorates

Engineering Contradiction:
Improvemanufacturing simplicityVSAvoidconnection tightness
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The patent maintains the advantage of thin-walled construction for manufacturing simplicity and weight reduction, while compensating for connection tightness issues by strategically placing latching connections at corner areas where the structure has sufficient rigidity to ensure secure engagement without requiring thicker walls throughout the entire duct.

Inventive Principle:
Principle #3Local quality

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 reduces flow resistance and improves connection tightness, maintaining comparable or better connection strength than conventional systems while preventing leaks and noise, ensuring efficient air flow and reduced assembly forces.

Implementation Method 1

the connecting sections are detachably connected to one another via at least one latching connection provided in the connecting region, the latching connection being formed from a latching element formed in the first connecting section and a counter-latching element formed in the second connecting section

Methodology Applied
Scientific EffectMechanical Fastener: Mechanical Fastener

Implementation Method 2

the guided air flow, which can result in pressure losses within the air duct system

Methodology Applied
Scientific EffectFluid Flow:

Data Source

PatentEP3034337B1Air conduit system for a motor vehicle
Publication Date: 2019.05.29 REHAU AG & CO
  • EP3034337B1 patent drawingFigure 1
  • EP3034337B1 patent drawingFigure 2
  • EP3034337B1 patent drawingFigure 3

AI summary

The present invention relates to an air duct system for a motor vehicle, comprising at least two air ducts (1, 2) produced in a blow molding process or 2-plate thermoforming process, the air ducts (1, 2) being in a common connecting area (3) overlap in such a way that a first connecting section (4) of the first air duct (1) is surrounded by a second connecting section (5) of the second air duct (2) and, wherein the connecting sections (4, 5) have polygonal cross sections that correspond to one another, and the connecting sections (4, 5) being detachably connected to one another via at least one latching connection (6) provided in the connecting region (3), the latching connection (6) consisting of a latching element (7) formed in the first connecting section (4) and a latching element (7) formed in the second connecting portion (5) formed counter-locking element (8), wherein the locking element (7) and the counter-lock element (8) are arranged on the respective corners (9a, 9b, 9c, 9d, 10a, 10b, 10c, 10d) of the connecting sections (4, 5) which abut one another.