Vehicle Panel Bonding Structure for Thermal Strain Management

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Solution Overview

Problem

Existing bonding structures for vehicle members with different thermal expansion coefficients generate thermal strain, which can lead to noticeable deformations and reduced bonding strength when materials with varying thermal expansion coefficients are used.

Innovation Solution

A bonding structure that includes a resin or metal panel with a smaller thermal expansion coefficient bonded to a resin panel using both an outside and inside bonding portion, where the inside bonding portion is designed to overlap the ridge line of the resin panel, improving stiffness and bonding strength while making thermal strain deformations unnoticeable by compensating strain in different directions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If members with different thermal expansion coefficients are bonded together, then bonding strength is achieved, but thermal strain is generated on the member with larger thermal expansion coefficient

Engineering Contradiction:

Improvebonding strengthVSAvoidthermal strain

Core Design Contradiction:

StrengthVSObject-generated harmful factors

Solution Approach 1:

The bonding structure is divided into multiple bonding portions (first bonding portion and second bonding portion) located at different positions. This segmentation allows differential thermal strain management, where each bonding portion can accommodate strain in different directions, preventing concentrated deformation at single locations.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different bonding portions are positioned to have different orientations relative to the ridge line. The first bonding portion is arranged with its bonding line extending in a first direction, while the second bonding portion extends in a second direction different from the first. This local variation in bonding orientation allows each portion to resist thermal strain differently, distributing the stress management function across the structure.

Inventive Principle:

Principle #3Local quality

2Ease of manufacture

If a single bonding portion is used to bond panels with different thermal expansion coefficients, then bonding is achieved, but noticeable deformation occurs due to concentrated thermal strain

Engineering Contradiction:

Improvebonding simplicityVSAvoidpanel deformation

Core Design Contradiction:

Ease of manufactureVSShape

Solution Approach 1:

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The bonding portions are arranged asymmetrically with respect to the ridge line orientation. The bonding lines of different portions extend in different directions relative to the ridge line, creating an asymmetric bonding pattern that distributes thermal strain more evenly across the panel structure, reducing noticeable deformation.

Inventive Principle:

Principle #4Asymmetry

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 effectively inhibits thermal strain and enhances bonding strength between panels with different thermal expansion coefficients, making the deformations due to thermal strain less noticeable and improving the overall structural integrity of vehicle components.

Implementation Method 1

when materials each having a different thermal expansion coefficient are used for the outer panel and the inner panel, when these panels are bonded together, thermal strain may be generated on a panel side having a larger thermal expansion coefficient

Methodology Applied

Scientific EffectThermal expansion: Thermal Expansion

Data Source

PatentUS9931914B2Bonding structure of vehicle members and bonding structure of backdoor

Publication Date: 2018.04.03 TOYOTA JIDOSHA KK

AI summary

A bonding structure of vehicle members includes a first member formed of resin in a shape of a panel and in which a ridge line is formed by an angular portion divided with respect to a curvature of other portion of a surface thereof, a second member formed in a shape of a panel with resin or metal having a smaller thermal expansion coefficient than the first member, an outside bonding portion provided on an outer edge side of the first member to bond together the first member and the second member, and an inside bonding portion provided inside of the outside bonding portion in a plane direction of the first member and bonds together the first member and the second member, at least one of plural apexes in a proximity of the outside bonding portion overlapping the ridge line when viewed from outside of the vehicle.