Laser-Welded Joint Structure for Mixed-Material Assembly

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Solution Overview

Problem

Conventional spot welding methods are inefficient for joining different-type materials, requiring complex rivet designs, long processing times, and limited flexibility due to the need for precise positioning and pressure application, which increases production costs and reduces productivity.

Innovation Solution

A joint structure where a different-type material is sandwiched between two same-type metal materials, with a penetrating part allowing laser light to create a weld bead that compressively fixes the different-type material, optimizing the plate thickness of the same-type materials to achieve effective fusion and bonding.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If spot welding is used to join different-type materials, then joint strength can be achieved, but processing time increases and productivity decreases

Engineering Contradiction:

Improvejoint strengthVSAvoidprocessing time

Core Design Contradiction:

StrengthVSProductivity

Solution Approach 1:

The patent replaces the mechanical pressure application system of spot welding with a laser-based thermal processing system. The laser beam delivers energy directly to the welding position without requiring mechanical pressure, eliminating the need for heavy welding guns and complex positioning mechanisms. This substitution dramatically reduces processing time while maintaining joint strength through controlled melting and solidification of materials.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent changes the fundamental processing parameter from mechanical pressure (spot welding) to thermal energy concentration (laser welding). By controlling laser power, beam focus, and scanning speed, the process achieves rapid heating and cooling cycles that create strong joints in seconds, compared to the minutes required for spot welding including pressure application and cooling time.

Inventive Principle:

Principle #35Parameter changes

2Strength

If spot welding is used to join different-type materials, then joint strength can be achieved, but device complexity increases due to required pressure application and positioning

Engineering Contradiction:

Improvejoint strengthVSAvoidwelding gun structure

Core Design Contradiction:

StrengthVSDevice complexity

Solution Approach 1:

The patent eliminates the complex mechanical pressure application system by using laser energy to create and maintain the weld pool. The laser beam itself provides the necessary energy concentration without requiring heavy electrodes, pressure mechanisms, or complex positioning systems. This simplifies the overall welding system while achieving comparable or superior joint strength.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Strength

If conventional welding methods are used for different-type materials, then joint strength can be achieved, but design flexibility is reduced due to positioning constraints

Engineering Contradiction:

Improvejoint strengthVSAvoiddesign flexibility

Core Design Contradiction:

StrengthVSAdaptability or versatility

Solution Approach 1:

The patent employs a dynamic laser scanning system that can rapidly reposition the beam to any location on the workpiece without mechanical constraints. The laser system can adapt to complex geometries and varying material combinations by adjusting beam parameters and scanning patterns in real-time, providing unprecedented design flexibility while maintaining strong joints across different material types.

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 approach significantly reduces processing time by up to 75% compared to spot welding, enhances joint stiffness, and increases design flexibility while maintaining strong bonding without the need for complex rivet shapes, thus improving productivity and reducing production costs.

Implementation Method 1

laser light is emitted toward an emission region in the penetrating part

Methodology Applied

Scientific EffectLaser heating: Laser

Implementation Method 2

the first material and the second material are fused and bonded together via the penetrating part

Methodology Applied

Scientific EffectLaser welding: Laser Beam Welding

Implementation Method 3

the first material and the second material are fused and bonded together via the penetrating part, by which the different-type material is compressed and fixed

Methodology Applied

Scientific EffectCompressive force from solidification: Compression

Data Source

PatentUS11376691B2Joint structure

Publication Date: 2022.07.05 PANASONIC INTELLECTUAL PROPERTY MANAGEMENT CO LTD

AI summary

A joint structure includes: a first same-type metal member; a second same-type metal member that can be mutually welded with the first same-type metal member; and a different-type member that has a penetrating portion, is interposed between the first same-type metal member and the second same-type metal member. In the plate thickness direction of an emission region in which a laser beam is emitted toward the penetrating portion, the plate thickness at the emission region of the first same-type metal member positioned on the side on which the laser beam is emitted is a predetermined thickness corresponding to a first gap. The first same-type metal member and the second same-type metal member are fused and bonded together via the penetrating portion, and the different-type member is compressed and fixed, such that the different-type member is fixed to the first same-type metal member and the second same-type metal member.