Laser Welding Tack Nugget Surround for Deformation Control

Solution Overview

Problem

Existing welding methods using high-energy beams face challenges in inhibiting deformation and peeling of tack welds during final welding, leading to potential abnormal noise and reduced strength due to the weakness of tack welds compared to final welds.

Innovation Solution

A welding method that forms a tack weld nugget and surrounds it with final weld nuggets along a virtual closed curve, ensuring the tack weld is left intact and supported by the final welds, thereby maintaining deformation inhibition and preventing peeling.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stability of the object's composition

If final welding is performed on top of a tack weld, then the deformation inhibiting effect is lost, but if final welding is performed near the tack weld and the tack weld is left, then peeling may occur

Engineering Contradiction:

Improvedeformation inhibitionVSAvoidtack weld strength

Core Design Contradiction:

Stability of the object's compositionVSStrength

Solution Approach 1:

The tack weld is formed in advance before final welding to inhibit deformation during the welding process. The tack weld serves as a preliminary structural support that maintains dimensional stability during subsequent welding operations.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The welding process is divided into two distinct stages: tack welding followed by final welding. The tack weld creates discrete anchor points that prevent deformation, while the final welding process adds strength without compromising the deformation inhibition provided by the tack weld structure.

Inventive Principle:

Principle #1Segmentation

2Stability of the object's composition

If the tack weld is left after final welding, then deformation is inhibited, but the weak tack weld may peel and produce abnormal noise

Engineering Contradiction:

Improvedeformation inhibitionVSAvoidpeeling and abnormal noise

Core Design Contradiction:

Stability of the object's compositionVSObject-affected harmful factors

Solution Approach 1:

The tack weld is formed in advance before final welding to inhibit deformation during the welding process. The tack weld serves as a preliminary structural support that maintains dimensional stability during subsequent welding operations.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The welding process is divided into two distinct stages: tack welding followed by final welding. The tack weld creates discrete anchor points that prevent deformation, while the final welding process adds strength without compromising the deformation inhibition provided by the tack weld structure.

Inventive Principle:

Principle #1Segmentation

3Ease of manufacture

If spot welding is used for tack welding, then the need for jig or temporary fixing is eliminated, but the tack weld protrudes from the continuous weld and may peel

Engineering Contradiction:

Improveelimination of jig or temporary fixingVSAvoidtack weld strength

Core Design Contradiction:

Ease of manufactureVSStrength

Solution Approach 1:

The spot weld automatically serves dual functions: it acts as a tack weld to prevent deformation during laser welding and eliminates the need for separate jigs or temporary fixing devices. The welding process itself provides the positioning and stabilization functions.

Inventive Principle:

Principle #25Self-service

Solution Approach 2:

The spot weld combines multiple functions into a single operation: it provides deformation inhibition during laser welding and eliminates the need for separate positioning fixtures. This merging of functions simplifies the manufacturing process while maintaining effectiveness.

Inventive Principle:

Principle #5Merging (Combining)

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 effectively inhibits deformation during final welding and prevents peeling of the tack weld after final welding, maintaining structural integrity and eliminating abnormal noise issues.

Implementation Method 1

a welding method by laser welding is widely used

Methodology Applied

Scientific EffectLaser beam welding: Laser Beam Welding

Implementation Method 2

using a high-energy beam such as a laser beam, an electron beam, or an ion beam

Methodology Applied

Scientific EffectElectron beam welding: Electron Beam

Implementation Method 3

using a high-energy beam such as a laser beam, an electron beam, or an ion beam

Methodology Applied

Scientific EffectIon beam welding: Ion Beam

Data Source

PatentUS10076807B2Welding method

Publication Date: 2018.09.18 TOYOTA JIDOSHA KK

AI summary

A welding method according to the invention is a welding method in which welding is performed by emitting a high-energy beam onto a welding object that includes a plurality of overlapped metal sheets. This welding method includes forming a tack weld nugget at a welding point on the welding object, and forming a plurality of final weld nuggets along a virtual closed curve that encircles the tack weld nugget, while leaving the tack weld nugget, at the welding point.