Welded Steel Motor Vehicle Component With Beveled Thick-Thin Joint

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Solution Overview

Problem

Existing welding methods for automotive components with varying wall thicknesses struggle to achieve high weld penetration into the thicker component without causing burn-through in the thinner component, leading to reduced service life and compromised joint strength.

Innovation Solution

A method involving a bevel and V-shaped joint gap configuration is applied to the components, where the bevel is created without machining by controlled plastic deformation, ensuring high penetration into the thicker component while preventing burn-through in the thinner one, facilitated by a weld seam that utilizes the bevel and V-shaped gap to enhance penetration depth.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If conventional welding methods are used to join components with different wall thicknesses, then welding process simplicity is maintained, but weld penetration into the thicker component is insufficient and burn-through occurs in the thinner component

Engineering Contradiction:
Improveweld penetration depthVSAvoidjoint strength
Core Design Contradiction:
Manufacturing precisionVSReliability

Solution Approach 1:

The invention applies a bevel specifically to the thicker component's joining surface, creating a localized geometric modification only where needed. This allows the thicker component to receive adequate weld penetration while the thinner component maintains its original geometry and avoids burn-through, resolving the contradiction between penetration depth and joint reliability

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The bevel is prepared in advance on the thicker component before the welding process. This preliminary geometric preparation creates optimal conditions for weld penetration without requiring complex welding parameters or procedures during the actual welding operation, thereby improving penetration while maintaining process simplicity

Inventive Principle:
Principle #10Preliminary action

2Manufacturing precision

If the welding parameters are increased to improve penetration into the thicker component, then weld penetration depth increases, but burn-through occurs in the thinner component

Engineering Contradiction:
Improveweld penetration depthVSAvoidburn-through
Core Design Contradiction:
Manufacturing precisionVSObject-affected harmful factors

Solution Approach 1:

The bevel creates a localized geometry change only on the thicker component, allowing increased penetration in that specific area while the thinner component remains unaffected. This spatial differentiation resolves the contradiction between achieving sufficient penetration and avoiding burn-through in different components

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

Instead of adjusting welding parameters (one dimension), the invention modifies the geometric dimension of the joining surface by adding a bevel. This dimensional change provides an additional degree of freedom to control penetration depth without affecting the thermal balance that causes burn-through in thinner components

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

3Reliability

If a bevel is added to the joining surface to improve penetration, then weld penetration and joint strength are enhanced, but manufacturing complexity increases

Engineering Contradiction:
Improvejoint strengthVSAvoidjoining surface geometry
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The invention changes the geometric parameter of the joining surface by adding a bevel with specific angle and depth parameters. This parameter modification directly improves joint strength through enhanced penetration while the bevel's simple conical geometry minimizes the increase in manufacturing complexity

Inventive Principle:
Principle #35Parameter changes

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 method achieves reliable penetration of 2% to 10%, with potential for up to 50%, enhancing joint strength and service life without increasing weight, resulting in a stable welded joint suitable for automotive components like twist-beam axles.

Implementation Method 1

the bevel is created without machining by controlled plastic deformation

Methodology Applied
Scientific EffectPlastic deformation: Plasticity

Implementation Method 2

Welding is the permanent, material-to-material joining of components using heat and pressure

Methodology Applied
Scientific EffectWelding: Welding

Data Source

PatentEP4537973B1Method for the production of a motor vehicle component
Publication Date: 2025.10.01 BENTELER AUTOMOBILTECHNIK GMBH
  • EP4537973B1 patent drawingFigure 1a~1d
  • EP4537973B1 patent drawingFigure 2a~2b
  • EP4537973B1 patent drawingFigure 3

AI summary

A motor vehicle component 2 comprises two steel parts 1, 11 with different wall thicknesses t1, t2, arranged at an angle α to each other and joined by a weld 18. A joining surface 13 at the end section 5 of the first part 1 has a chamfer 7 formed without machining. To form the chamfer 7, an end section 5 of a starting blank 3 is formed without machining. Subsequently, the end section 5 is trimmed and a butt surface 10 is created on the end face of the end section 5. The two parts 1, 11 are positioned relative to each other so that the joining surface 13 of the first part 1 and the joining surface 14 of the second part 11 face each other. The material-locking connection of the first part 1 and the second part 11 is achieved by a weld 18 at the joining surfaces 13, 14.