Welding Stud Washer Latching for Automated Tolerance Compensation

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Solution Overview

Problem

Existing fastening systems in vehicle construction have limited contact surfaces, making it difficult to compensate for tolerances and are not suitable for fully automated welding processes due to the size of washers, which restricts the accuracy of bolt placement during automated joining.

Innovation Solution

A fastening system featuring a welding stud with a large flange and a washer that snaps into a thread-free area of the pin-shaped section, providing a larger bearing surface and latching mechanism to secure the washer in place, allowing for accurate positioning and compensation of tolerances in automated welding processes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Area of stationary object

If a washer with large outer diameter is permanently connected to the welding stud, then the contact surface is enlarged, but the fastening element cannot be used in fully automated processes due to feed hose diameter limitations

Engineering Contradiction:
Improvecontact surface areaVSAvoidautomated welding process compatibility
Core Design Contradiction:
Area of stationary objectVSExtent of automation

Solution Approach 1:

The fastening element is divided into two separate components: the welding stud and the washer. The welding stud without a permanently attached washer can be fed through standard diameter feed hoses in automated processes, while the washer is applied separately after welding, thus resolving the contradiction between enlarged contact surface and automated process compatibility

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The welding stud is welded to the carrier before the washer is applied. This preliminary welding action allows the stud to be positioned accurately by automated systems, and the washer is subsequently attached to provide the enlarged contact surface, separating the positioning function from the bearing surface function

Inventive Principle:
Principle #10Preliminary action

2Manufacturing precision

If the opening in the component is made large to accommodate positional deviations, then positional tolerance is compensated, but the support of the component on the flange becomes inadequate

Engineering Contradiction:
Improvepositional accuracyVSAvoidcomponent support strength
Core Design Contradiction:
Manufacturing precisionVSStrength

Solution Approach 1:

The solution moves from relying solely on the flange diameter in one dimension to using a washer that extends the bearing surface in a different dimensional configuration. The washer provides additional radial support area independent of the flange size, allowing the opening to be sized for positional tolerance while maintaining adequate component support through the enlarged washer contact surface

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

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 system achieves a larger contact surface for components, enabling accurate positioning and secure attachment even with multiple robots, and can withstand rotational forces and processes like cathodic dip painting, while being compatible with automated welding robots.

Implementation Method 1

The welding stud (2) is fastened to the carrier (1) by means of a welding process

Methodology Applied
Scientific EffectWelding: Welding

Implementation Method 2

the latching means (33) are elastically or plastically deformable

Methodology Applied
Scientific EffectElastic deformation: Elasticity

Implementation Method 3

the latching means (33) are elastically or plastically deformable

Methodology Applied
Scientific EffectPlastic deformation: Plasticity

Data Source

PatentEP3197631B1Fastening system and method for producing a fastening system
Publication Date: 2018.06.13 BAYERISCHE MOTOREN WERKE AG
  • EP3197631B1 patent drawingFigure 1~3c
  • EP3197631B1 patent drawingFigure 4~5

AI summary

A fastening system (100) which comprises a welding stud (2) that is weldable to a carrier (1) and a disc (3) that is fastened to the welding stud (2) and has an opening (31) is specified. The welding stud (2) comprises a weld-on portion (21) for welding the welding stud (2) onto the carrier (1), a flange (22) and a pin-like portion (23) having an external thread (231). The disc (3) has an outside diameter (32) which is greater than a diameter (221) of the flange (22). The pin-like portion (23) has a thread-free region (235) which is arranged between the flange (22) and the external thread (231), and the disc (3) has latching means (33) which are configured for pushing the disc (3) over the external thread (231) and by means of which the disc (3) is latched in place in the thread-free region (235). Furthermore, a method for producing a fastening system (100) is specified.