Self-Piercing Rivet Shank Slits for Joining Strength
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Solution Overview
Problem
Conventional self-piercing rivets often result in weakened joining strength and rotation issues due to the complete cutting off of the penetrated portion, requiring multiple rivets to prevent rotation and increasing complexity and cost.
Innovation Solution
A self-piercing rivet design featuring a shank with multiple slits that penetrates and deforms to create a mechanical interlock without completely cutting off the upper sheet, enhancing joining strength and preventing rotation with a single rivet.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If an annular piercing edge shank is used, then the shank can penetrate the upper sheet, but the penetrated portion is completely cut off and becomes dead metal, deteriorating joining strength
Solution Approach 1:
The shank is divided into multiple segments by forming slits along its length, creating multiple finger-like portions instead of a solid annular structure. This segmentation allows the penetrated portion to remain connected through the slits, preventing complete cutoff while maintaining penetration capability.
Solution Approach 2:
Different portions of the shank have different structural characteristics - the slits create localized flexibility and connectivity in certain areas while maintaining structural integrity in others, allowing the penetrated portion to remain attached rather than being completely severed.
2Stability of the object's composition
If multiple rivets are used to prevent rotation of the upper sheet, then rotation is prevented, but processes become complicated, productivity deteriorates, and product cost increases
Solution Approach 1:
The shank structure with slits performs multiple functions simultaneously: it prevents rotation of the upper sheet through the mechanical interlock of the finger-like portions, maintains joining strength by preserving the penetrated portion, and allows single-rivet operation to eliminate the need for additional anti-rotation rivets.
Solution Approach 2:
The shank structure itself provides the anti-rotation function through its slit-formed finger-like portions that interlock with the sheets, eliminating the need for separate anti-rotation mechanisms or additional rivets. The structure serves its own anti-rotation need.
3Ease of operation
If an annular piercing edge shank is used, then the shank penetrates the upper sheet, but the joining load increases
Solution Approach 1:
The slits divide the shank into multiple flexible finger-like portions that can deform more easily during penetration, distributing the penetration force across multiple segments rather than requiring high force on a solid annular structure.
Solution Approach 2:
The structural parameter of the shank is changed from a solid annular cross-section to a segmented structure with slits, which alters the mechanical properties to reduce penetration resistance and joining load while maintaining penetration capability.
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 design improves joining strength, reduces the need for multiple rivets, and decreases the joining load, thereby simplifying processes and reducing costs while maintaining stability and strength.
Implementation Method 1
the shank is deformed plastically and joins the joining objects
Implementation Method 2
the rivet is press-fitted into the joining objects by hydraulic pressure or pneumatic pressure
Implementation Method 3
the rivet is press-fitted into the joining objects by hydraulic pressure or pneumatic pressure
Data Source
AI summary
A self-piercing rivet is disclosed. The self-piercing rivet integrally joins an upper plate member and a lower plate member overlapped with each other. The self-piercing rivet includes: a head portion; and a shank portion integrally connected to the head portion and provided with more than two slits.