Clinching Ductile and Non-Ductile Components via Pilot Hole Undercut

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Solution Overview

Problem

Current clinching technologies are unable to effectively join ductile components with non-ductile components, such as steel or aluminum with carbon fiber reinforced plastic, without using auxiliary joining elements that increase weight and susceptibility to corrosion.

Innovation Solution

A method using a clinching device with a setting punch and die that sandwiches a non-ductile component between two ductile components, where the punch pulls material through a pilot hole in the non-ductile component to create an undercut connection, minimizing damage and corrosion risk.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If auxiliary joining elements such as rivets or screws are used to connect ductile components with non-ductile components, then the connection is achieved, but the total weight increases and susceptibility to corrosion increases

Engineering Contradiction:
Improveconnection reliabilityVSAvoidjoint weight
Core Design Contradiction:
ReliabilityVSWeight of moving object

Solution Approach 1:

The invention removes auxiliary joining elements (rivets, screws, adhesives) from the connection system entirely. Instead, it uses a clinching process where the ductile components are directly formed to create interlocking structures with the non-ductile component through material displacement and plastic deformation, achieving connection without additional fastening elements

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The invention replaces the mechanical fastening system (auxiliary joining elements) with a direct metal forming/cold joining system. The clinching process uses controlled plastic deformation and material flow to create permanent mechanical interlocking, substituting the need for separate fastening components with an integrated forming process

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Reliability

If auxiliary joining elements such as steel rivets are inserted when aluminum and carbon fiber plastic are connected, then the connection is achieved, but the susceptibility to corrosion increases due to expanding the electrochemical series

Engineering Contradiction:
Improveconnection reliabilityVSAvoidcorrosion susceptibility
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The invention extracts and eliminates metallic auxiliary joining elements from the connection system. By using direct clinching where ductile components are formed to interlock with the non-ductile component, no additional metallic materials are introduced, thereby preventing expansion of the electrochemical series and reducing galvanic corrosion risks

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The invention reduces material heterogeneity in the connection by avoiding introduction of third metallic materials. The connection system primarily involves the original two materials (ductile and non-ductile components) without adding steel rivets or other metallic fasteners that would create additional electrochemical interfaces

Inventive Principle:
Principle #33Homogeneity

3Ease of manufacture

If conventional clinching is used to join components, then the connection is achieved, but it cannot be applied to non-ductile materials without damage or destruction

Engineering Contradiction:
Improvejoining process simplicityVSAvoidnon-ductile component integrity
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The invention applies local quality by creating different deformation zones: the ductile components undergo plastic deformation and material displacement to form interlocking structures, while the non-ductile component is protected from direct deformation through the use of a pilot hole and controlled material flow paths that prevent damage

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The invention introduces a pilot hole as an intermediary feature in the non-ductile component. This pilot hole guides the material flow and allows the setting punch to pass through without directly deforming or damaging the non-ductile material, while still enabling the ductile components to be formed into interlocking structures

Inventive Principle:
Principle #24Intermediary (Mediator)

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 method enables a simple, cost-effective, and durable connection between ductile and non-ductile components, preventing damage to the non-ductile material and reducing corrosion risk by creating a gas and watertight joint without the need for auxiliary joining elements.

Implementation Method 1

the setting punch of the device is moved towards the die-side component and pulls a portion of the punch-side component through the pilot hole of the middle component until the entrained area is pressed against the die-side component

Methodology Applied
Scientific EffectPlastic deformation: Plasticity

Data Source

PatentEP2664394B1Method for clinching two ductile components with a non ductile component
Publication Date: 2014.06.11 BAYERISCHE MOTOREN WERKE AG
  • EP2664394B1 patent drawingFigure 1
  • EP2664394B1 patent drawingFigure 2~3
  • EP2664394B1 patent drawingFigure 4

AI summary

The present invention relates to a method for clinching three components (20, 30, 40) by means of a clinching device (1) comprising a setting punch (15) and a die (2) which has an anvil (3) with a recess (4) into which the setting punch (15) can be inserted, wherein the punch-side component (20) and the die-side component (40) each have a ductile material and the middle component (30) has a non-ductile material, wherein the middle component (30) has a pilot hole (31) through which the setting punch (15) can be passed.