Laser Fillet Welding Intensity Profile for Deeper Throat Depth

Solution Overview

Problem

In laser welding methods, the uneven intensity of the laser beam can lead to excessive burning of the upper metal plate's edge, resulting in a decreased throat depth and welding strength due to higher irradiation intensity on the upper side compared to the lower side.

Innovation Solution

The method involves adjusting the laser beam's intensity distribution so that the peak intensity is on the upper surface, with lower intensity towards the end surface, and optionally forming secondary peak areas, to ensure gradual melting and increased throat depth, thereby enhancing welding strength.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If the upper base material and the lower base material are both irradiated with a laser beam, then the welding process can be completed, but the edge of the upper base material is drastically burned through due to high irradiation intensity

Engineering Contradiction:

Improvewelding process completionVSAvoidburning through of upper base material edge

Core Design Contradiction:

ProductivityVSObject-affected harmful factors

Solution Approach 1:

The patent applies local quality by creating different intensity zones within the laser beam irradiation area. The laser beam intensity is specifically controlled to be lower at the position corresponding to the end surface of the upper base material compared to other areas, allowing selective melting without burning through the edge.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent changes the parameter of laser beam intensity distribution by positioning the peak intensity area away from the end surface of the upper base material. This parameter adjustment ensures that the laser beam provides sufficient energy for melting while preventing excessive intensity that would cause burning through.

Inventive Principle:

Principle #35Parameter changes

2Strength

If the laser beam intensity is high to ensure proper melting, then the welding can be effective, but the throat depth of the welding joint is decreased due to burning through

Engineering Contradiction:

Improvewelding strengthVSAvoidthroat depth of welding joint

Core Design Contradiction:

StrengthVSLength of moving object

Solution Approach 1:

The patent applies local quality by creating different intensity zones within the laser beam irradiation area. The laser beam intensity is specifically controlled to be lower at the position corresponding to the end surface of the upper base material compared to other areas, allowing selective melting without burning through the edge.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent changes the parameter of laser beam intensity distribution by positioning the peak intensity area away from the end surface of the upper base material. This parameter adjustment ensures that the laser beam provides sufficient energy for melting while preventing excessive intensity that would cause burning through.

Inventive Principle:

Principle #35Parameter changes

3Ease of manufacture

If the laser beam intensity is distributed evenly, then the processing is simple, but the end surface of the upper base material cannot be gradually molten leading to insufficient burn through

Engineering Contradiction:

Improvelaser beam processing simplicityVSAvoidgradual melting control of end surface

Core Design Contradiction:

Ease of manufactureVSManufacturing precision

Solution Approach 1:

The patent applies local quality by creating different intensity zones within the laser beam irradiation area. The laser beam intensity is specifically controlled to be lower at the position corresponding to the end surface of the upper base material compared to other areas, allowing selective melting without burning through the edge.

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 configuration effectively suppresses the intensity near the end surface of the upper base material, resulting in a deeper throat depth and improved welding strength by controlling the melting process and maintaining efficient laser welding operations.

Implementation Method 1

irradiating a laser beam so as to form an initial irradiation area on only the upper surface of the upper base material or on only both the upper surface and the end surface of the upper base material, whereby the end surface of the upper base material and the lower base material are fillet welded

Methodology Applied

Scientific EffectLaser heating: Laser

Implementation Method 2

the intensity of the laser beam is lower toward the second side from the first peak area within the irradiation area of the laser beam... the area near the end surface of the upper base material is gradually molten

Methodology Applied

Scientific EffectLaser heating with intensity control: Laser

Data Source

PatentUS11453085B2Method for manufacturing joined body

Publication Date: 2022.09.27 FUTABA IND CO LTD

AI summary

Firstly, an upper base material is disposed above a lower base material. Secondly, a laser beam is irradiated so that an area irradiated with a laser beam at a time of melting start is formed on only an upper surface of the upper base material or on only both the upper surface and an end surface of the upper base material, whereby the end surface of the upper base material and the lower base material are fillet welded. With the end surface as a reference, a side the upper surface and the lower surface are positioned is a first side, and an opposite side of the first side is a second side. The laser beam is set such that an intensity of the laser beam is lower toward the second side from the first peak area within the irradiation area of the laser beam.