Self-Piercing Rivet Grooves for Reversible High-Hold Joining
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Solution Overview
Problem
Existing punch riveting processes are largely non-releasable and irreversible, leading to damage when attempting to remove the rivet, and previous solutions either compromise holding force or result in inhomogeneous thread distribution, limiting the reusability and adjustability of the connection.
Innovation Solution
A punch rivet design featuring a rivet head with a driving profile, a rivet shaft with a thread and grooves that allow radial material flow, enabling increased thread filling and a secure, reversible connection, with adjustable parameters for tool compatibility and material distribution.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If self-piercing rivets with threads or circumferential grooves are used to enable removal, then the rivet can be rotated out with minimal effort, but the holding force is reduced due to irreversible expansion of the punched hole area
Solution Approach 1:
The invention changes the geometric parameters of the rivet shank by introducing grooves at specific positions and depths. These grooves create controlled material flow paths that allow the rivet to be removed while maintaining adequate holding force through optimized material distribution in the punched hole area.
2Strength
If material flows into the thread to create force and form fit, then the connection strength is enhanced, but the thread becomes inhomogeneous leading to uneven force distribution
Solution Approach 1:
The invention applies local quality by creating grooves at specific locations on the rivet shank rather than uniform threading throughout. This allows material to flow into specific zones (the grooves) to create local anchoring points, while maintaining thread homogeneity in other areas for even force distribution.
3Reliability
If the rivet is designed for permanent joining, then the connection is strong and reliable, but the rivet cannot be removed or reused
Solution Approach 1:
The invention makes the rivet system dynamic by allowing it to transition between two states: initially providing permanent, reliable joining through thread engagement, and later enabling removal and reuse through the groove mechanism that controls material flow and reduces extraction resistance.
4Strength
If circumferential ribs are used to create clamping force, then the joining is secure, but there is no provision for gentle removal or loosening of the joint
Solution Approach 1:
The grooves act as intermediaries between the rivet shank and the punched hole material. They control the material flow and create a transition zone that allows the rivet to be gently removed by rotation, mediating between the secure clamping force during joining and the ease of removal during disassembly.
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 solution provides a reliable, reversible joining process with enhanced holding force and reusability, preventing accidental loosening and allowing for efficient reuse of the punch rivet, while maintaining the strength and integrity of the connection.
Implementation Method 1
The rivet grooves enable a radial material flow along the rivet shank. This enables a radial material flow from the components, filling the thread groove and the rivet groove, thus forming the thread shape.
Implementation Method 2
The punch studs with a threaded outer surface or in the form of radially circumferential grooves are set at a partially increased joining speed through a purely translational movement, utilizing the elastic springback of the joining partners to create the connection.
Data Source
Figure 1~2
Figure 3~4
Figure 5
AI summary
The present invention comprises a self-piercing rivet (1) for self-piercing at least two components (7a, 7b). The self-piercing rivet (1) comprises a rivet head (2) with a drive profile (2a); a rivet shank (3) extending from the rivet head (2) with a rivet cutting edge (5) and a thread (4) arranged between the rivet cutting edge (5) and the rivet head (2). The rivet shank (3) has at least one rivet groove (6) that interrupts the thread (4) and optionally the rivet cutting edge (5). The diameter of the bottom of the at least one rivet groove (6) is equal to the thread core diameter of the thread (4). The present invention further comprises a method for self-piercing at least two components (7a, 7b) using such a self-piercing rivet.