Resin Panel Stiffener Connection for Thermal Deformation

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Solution Overview

Problem

Resin panels in vehicles face challenges with thermal expansion/contraction, as existing methods require protruding portions or holes, leading to sink formation and complex mold structures, which are not suitable due to the higher thermal expansion/contraction rates of resin compared to glass or metallic stiffeners.

Innovation Solution

A connecting structure where a resin frame with an extended part is integrated with a weather strip and metallic stiffener, using a guide cylinder and stud nut system to sandwich the extended part, allowing for thermal deformation accommodation without protrusions or holes on the resin panel, ensuring the resin panel's torsional rigidity and simplifying the mold structure.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If protruding portions or holes are formed on the resin panel to accommodate thermal expansion/contraction, then the deformation can be absorbed, but sinks are formed around the protruding portions or holes and the mold structure becomes complicated

Engineering Contradiction:
Improvethermal deformation accommodationVSAvoidmold structure complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The invention extracts the thermal expansion/contraction accommodation function from the resin panel itself and relocates it to the frame structure. The frame includes a movable portion that can move in the thickness direction, separating the deformation accommodation function from the panel body and eliminating the need for protruding portions or holes in the panel.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The movable portion of the frame acts as an intermediary between the resin panel and the external environment. It mediates the thermal expansion/contraction forces by moving in the thickness direction, protecting the resin panel from direct stress while accommodating the dimensional changes without requiring modifications to the panel structure.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Adaptability or versatility

If protruding portions or holes are formed on the resin panel to accommodate thermal expansion/contraction, then the deformation can be absorbed, but sink formation occurs around these features

Engineering Contradiction:
Improvethermal deformation accommodationVSAvoidsurface flatness
Core Design Contradiction:
Adaptability or versatilityVSManufacturing precision

Solution Approach 1:

The invention removes the need for protruding portions or holes in the resin panel by extracting the deformation accommodation function to the frame's movable portion. This maintains the resin panel's surface integrity and prevents sink formation while still accommodating thermal expansion/contraction through the frame's movement.

Inventive Principle:
Principle #2Taking out (Extraction)

3Strength

If adhesive agents are used to attach metallic stiffener to glass panel, then the connection is effective due to similar thermal expansion rates, but this method cannot be applied to resin panels with higher thermal expansion rates

Engineering Contradiction:
Improveconnection strengthVSAvoidmaterial compatibility
Core Design Contradiction:
StrengthVSAdaptability or versatility

Solution Approach 1:

The movable portion of the frame serves as an intermediary between the resin panel and the metallic stiffener. It absorbs the thermal expansion/contraction differences through its movement capability, allowing the stiffener to remain firmly connected to the panel without requiring adhesive agents, thus accommodating different material properties.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The frame's movable portion introduces dynamic movement capability to the connection system. Instead of relying on static adhesive bonds that fail with differential thermal expansion, the movable portion dynamically adjusts its position in the thickness direction to accommodate thermal changes while maintaining connection integrity.

Inventive Principle:
Principle #15Dynamics

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 solution effectively manages thermal expansion/contraction deformation of resin panels by adjusting the pinching force of the weather strip and stiffener, preventing sink formation and maintaining the resin panel's torsional rigidity while simplifying the mold and assembly process, and ensuring a watertight seal.

Implementation Method 1

the resin panel is deformed by a thermal expansion/contraction

Methodology Applied
Scientific EffectThermal expansion/contraction: Thermal Expansion

Data Source

PatentEP2329979B1Connecting structure of resin panel and stiffener for vehicle
Publication Date: 2014.10.15 YACHIYO IND CO LTD
  • EP2329979B1 patent drawingFigure 1
  • EP2329979B1 patent drawingFigure 2
  • EP2329979B1 patent drawingFigure 3

AI summary

A connecting structure of a resin panel and a stiffener for a vehicle, including the resin panel, a resin frame attached to a circumference of the resin panel; a weather strip attached to the frame; a metallic stiffener which is provided at the vicinity of the circumference of the resin panel; wherein the frame includes an extended part which extends outside of a side of the resin panel and the weather strip and the stiffener are integrally connected such that the weather strip and the stiffener sandwich the extended part, and wherein the frame is moved against a pinching force of the weather strip and the stiffener when the resin panel is deformed by a thermal expansion/contraction.