Blind Rivet Shank Weakening for Precise Closing Head Formation
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Solution Overview
Problem
Conventional blind rivet nuts face issues with undefined closing head formation, limited clamping range, and high production costs due to long lengths and complex designs, which hinder their application in thin materials and require significant material and machine resources.
Innovation Solution
A blind rivet element with a shank weakened by holes in the central peripheral area of the deformation section, allowing for precise formation of a circumferential closing head and increased clamping area without extensive lengthening, enabling secure fastening in thinner materials and reducing production costs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If conventional blind rivet nuts are used with high strength requirements, then reliable fastening is achieved, but application to thin materials like plastic or sandwich construction is limited
Solution Approach 1:
The shank is designed with non-uniform wall thickness, featuring a thinned central peripheral area in the deformation section while maintaining sufficient wall thickness at the ends. This local quality variation allows controlled deformation in the thinned area to form a reliable closing head, while the thicker end areas maintain structural integrity for threading and setting operations, enabling reliable fastening across diverse materials including thin materials like plastic and sandwich construction
2Adaptability or versatility
If the deformation section is extended to increase clamping range, then more material thicknesses can be accommodated, but the blind rivet nut becomes longer and requires more material and machine costs
Solution Approach 1:
Instead of uniformly extending the deformation section, the invention applies local quality by thining the shank wall specifically in the central peripheral area of the deformation section. This allows the deformation zone to be effectively extended for increased clamping range while keeping the overall length compact, as the thinned area requires less material and can be processed more efficiently, reducing both material consumption and machine costs
3Manufacturing precision
If the shank wall is significantly weakened to ensure defined closing head formation, then reliable fastening in thin materials is achieved, but the shank strength is reduced
Solution Approach 1:
The shank wall is thinned only in the central peripheral area of the deformation section, not throughout the entire shank. This localized weakening provides sufficient plasticity for defined closing head formation in thin materials, while the thicker end areas maintain adequate shank strength for withstanding setting forces and providing thread support, thus balancing formation precision with structural strength
4Device complexity
If conventional blind rivet nuts are used, then simple design is maintained, but closing head formation becomes undefined in thin materials leading to buckling or folding
Solution Approach 1:
The invention introduces a localized feature (thinned central peripheral area) rather than a complex overall design. This simple yet effective modification to the shank's wall thickness distribution provides defined closing head formation in thin materials while maintaining relatively simple manufacturing processes and design, avoiding the need for complex multi-component structures or elaborate deformation control mechanisms
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 blind rivet element with a significantly larger clamping range and higher clamping force, expanded application in various materials, including plastics and sandwich constructions, while maintaining a shorter length and lower production costs compared to conventional designs.
Implementation Method 1
the shank (3) has a weakening (6) of the shank wall in a central peripheral area of the deformation section (5) to form a circumferential closing head (11) in the form of a circumferential bead after deformation of the blind rivet element (1)
Data Source
Figure 1~2
Figure 3
Figure 4~5
AI summary
The invention relates to a blind rivet element (1), in particular a blind rivet nut or blind rivet threaded stud, with a setting head (2) and a shank (3), wherein the shank has an internal thread (4) or a threaded stud receptacle in the region of its end facing away from the setting head (2), and a deformation section (5) between the internal thread or threaded stud receptacle and the setting head, and the setting head has a larger outer diameter than the shank. The shank exhibits a weakening of the shank wall (6) exclusively in a central circumferential region (15) of the deformation section (5). Such a blind rivet element is characterized by a destabilized area that deforms in a defined manner when the element is set, the element having a short overall length and thus low material costs. The element can be manufactured easily and cost-effectively and is simple to set.Such a blind rivet element is quite suitable for use in connection with a component in which the closing head of the blind rivet element, formed after the deformation of the blind rivet element, engages radially in a recess of the component.