Friction-Welded Connecting Element for Low-Profile Sheet Metal Joints

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Solution Overview

Problem

Existing component connection designs require a large structural height with a small diameter, particularly in thin sheet metal applications, which is inefficient.

Innovation Solution

A connecting element with a head and shank design where the material protrudes laterally beyond the head, encloses it, and has a continuous increase in diameter from the shank to the head, ensuring a form-fitting connection with a low installation height by controlling the displacement of softened material radially outward.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If the connecting element has a head with sufficient distance to the weld bead for drive structure engagement, then the drive torque can be transmitted effectively, but the installation height increases

Engineering Contradiction:
Improvedrive torque transmissionVSAvoidinstallation height
Core Design Contradiction:
StrengthVSLength of stationary object

Solution Approach 1:

The patent transitions from a conventional design where the drive recess is located directly under the head to a design where the drive recess is positioned laterally offset from the head's vertical axis. This dimensional repositioning allows the drive structure to engage with the weld bead at an optimal distance for torque transmission while maintaining a compact overall height, as the drive engagement occurs in a lateral rather than vertical dimension

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

2Area of stationary object

If the head diameter is reduced for thin sheet applications, then the connection becomes more suitable for thin sheets, but the structural height must be reduced which limits drive structure space

Engineering Contradiction:
Improvehead diameterVSAvoidstructural height
Core Design Contradiction:
Area of stationary objectVSLength of stationary object

Solution Approach 1:

The patent repositions the drive recess laterally offset from the head's vertical axis, utilizing lateral space rather than vertical space. This allows the head diameter to be minimized for thin sheet applications while the drive structure still has sufficient engagement distance with the weld bead, as the drive engagement occurs in the lateral dimension rather than requiring increased vertical height

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

3Strength

If the distance between the weld bead and head level is increased for adequate pull-out strength, then the connection strength improves, but the installation height increases

Engineering Contradiction:
Improvepull-out strengthVSAvoidinstallation height
Core Design Contradiction:
StrengthVSLength of stationary object

Solution Approach 1:

The patent positions the drive recess laterally offset from the head's vertical axis, allowing the vertical distance between the weld bead and head level to be minimized for low installation height while the lateral offset provides sufficient engagement distance for drive torque transmission. This dimensional separation resolves the contradiction between connection strength and installation height

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

This design achieves a low construction height while maintaining high strength and pull-out force, ensuring a secure and efficient component connection.

Implementation Method 1

the shaft being welded to the base layer at its end face. Thus, the connecting element forms a material-bonded connection with the base layer via its shaft

Methodology Applied
Scientific EffectFriction welding: Friction Welding

Implementation Method 2

The head has a recess on its underside into which material softened during the friction welding process, in particular from the top layer, can be received

Methodology Applied
Scientific EffectFriction welding: Friction Welding

Data Source

PatentEP3253527B1Workpiece arrangement with a friction-welded connection
Publication Date: 2020.12.30 EJOT GMBH & CO KG
  • EP3253527B1 patent drawingFigure 1a~2
  • EP3253527B1 patent drawingFigure 3~4a
  • EP3253527B1 patent drawingFigure 4b~5

AI summary

The invention relates to a connecting element (10, 20, 30, 50) for producing a component connection (70) of two components (72, 74; 92) lying against each other by means of the connecting element (10, 20, 30, 50), which is welded to the lower layer (74) - the base layer - by friction, wherein the connecting element (10, 20, 30, 50) has a shaft (18), which has a shaft segment (14) and a head (12) having a flat surface (20) lying on the top side of the head for transmitting the axial force, wherein a drive cut-out (22, 32) is introduced into the flat surface (20) in order to transmit a torque. The invention is characterized in that a continuous diameter increase starting at an ascent level (A) on the shaft segment (18) to the bottom side of the head results, wherein the distance from the ascent level (A) to a head bottom-side level (K), which has the greatest distance from the shaft end, is less than half the difference between the head outside diameter and the shaft diameter at the ascent level (DA - DS) / 2 (D2) and greater than a quarter of the difference between the head outside diameter and the shaft diameter at the ascent level (DA - DS) / 4 (D1).