Panel Structure With Differential Insertion Holes For Thermal Expansion

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Solution Overview

Problem

The existing panel structure faces issues with thermal expansion mismatch between panels and reinforcements, leading to stress concentration and reduced fixing strength, as well as coating scratches due to thermal expansion of materials with different coefficients.

Innovation Solution

The panel structure incorporates a reinforcement with a larger insertion hole diameter in the direction of thermal expansion, allowing the fixing member to move relative to the reinforcement while maintaining contact with the panel, thus preventing coating scratches and ensuring sufficient fixing strength.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If the panel is made of material with higher thermal expansion coefficient than the reinforcement and the panel's insertion hole is made larger in diameter, then the fixing strength is maintained during thermal expansion, but the coating around the fixing member is scratched due to relative movement

Engineering Contradiction:

Improvefixing strengthVSAvoidcoating quality

Core Design Contradiction:

StrengthVSManufacturing precision

Solution Approach 1:

Instead of making the panel's insertion hole larger to prevent stress concentration, the invention makes the reinforcement's insertion hole larger. This reverses the conventional approach: the panel's hole remains small to maintain coating quality, while the reinforcement's hole is enlarged to accommodate thermal expansion, allowing the fixing member to move relative to the reinforcement rather than the panel

Inventive Principle:

Principle #13The other way round (Inversion)

Solution Approach 2:

The fixing member acts as an intermediary element that connects the panel and reinforcement. By allowing the fixing member to move within the enlarged reinforcement insertion hole, it mediates the thermal expansion difference between the panel and reinforcement, preventing stress concentration while maintaining a stable connection point on the panel for the coating

Inventive Principle:

Principle #24Intermediary (Mediator)

2Stability of the object's composition

If the panel's insertion hole is made larger in diameter to avoid firm contact during thermal expansion, then stress concentration is reduced, but the relative position change between panel and fixing member causes coating scratches

Engineering Contradiction:

Improvestress distributionVSAvoidcoating surface quality

Core Design Contradiction:

Stability of the object's compositionVSManufacturing precision

Solution Approach 1:

The invention inverts the design by keeping the panel's insertion hole small (maintaining firm contact and coating quality) while enlarging the reinforcement's insertion hole. This allows the fixing member to move relative to the reinforcement instead of the panel, achieving both stress distribution and coating protection

Inventive Principle:

Principle #13The other way round (Inversion)

3Strength

If the fixing member is firmly contacted by the panel during thermal drying, then the fixing strength is maintained, but the coating is pulled and scratched when the panel thermally expands

Engineering Contradiction:

Improvefixing strengthVSAvoidcoating damage

Core Design Contradiction:

StrengthVSObject-affected harmful factors

Solution Approach 1:

The invention reverses the conventional design by maintaining firm contact between the fixing member and the panel (small panel hole) while allowing movement relative to the reinforcement (large reinforcement hole). This ensures fixing strength is maintained through firm panel contact while coating damage is prevented by allowing movement at the reinforcement interface

Inventive Principle:

Principle #13The other way round (Inversion)

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 configuration prevents coating scratches and maintains the appearance and anticorrosive properties of the panel structure while maintaining the fixing strength between the panel and reinforcement.

Implementation Method 1

if the panel and the reinforcement have different thermal expansion coefficients, one of the panel or the reinforcement may further expand thermally than the other in a certain direction when heat is applied to the panel structure

Methodology Applied

Scientific EffectThermal expansion: Thermal Expansion

Implementation Method 2

When the coating material thus applied is thermally dried, the panel having a higher expansion coefficient thermally expands

Methodology Applied

Scientific EffectThermal drying: Evaporation

Data Source

PatentUS10639978B2Panel structure and method for producing same

Publication Date: 2020.05.05 WEBASTO JAPAN CO LTD

AI summary

A panel structure 30 includes a panel 40 having a first insertion hole 42, a reinforcement 50 having a second insertion hole 52, and a fixing member 70 having a shaft 71 inserted in the first and second insertion holes 42 and 52, and sandwiching and fixing the panel 40 and the reinforcement 50 in their thickness direction. The panel 40 has a higher thermal expansion coefficient than the reinforcement 50. A diameter of the second insertion hole 52 in a direction of thermal expansion of the panel 40 is larger than a diameter of the first insertion hole 42 in the direction.