Blind Rivet Nut Enlarged Bearing Surface

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Solution Overview

Problem

Existing blind rivet nuts fail to ensure ideal force transmission, particularly with modern materials like CFRP or GFRP, leading to potential damage from force and tension peaks in high-load situations.

Innovation Solution

A blind rivet nut with a rivet shaft and enlarged rivet head bearing surface, where the bearing surface is at least 1.2 times the radial dimension of the rivet shaft, providing improved force transmission and reduced surface pressure, and optionally made from stainless steel with a protective coating for corrosion resistance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a conventional blind rivet nut is used, then the connection can be established, but force transmission is not ensured and tension peaks occur in high-load situations

Engineering Contradiction:

Improveforce transmissionVSAvoidsurface pressure

Core Design Contradiction:

ReliabilityVSStress or pressure

Solution Approach 1:

The bearing surface of the rivet head is enlarged in the radial direction (another dimension) to distribute the load over a larger area. This dimensional expansion reduces the surface pressure concentration that causes tension peaks, while maintaining reliable force transmission through the connection.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The rivet head is designed with a pre-calculated bearing surface area (at least 1.2 times the radial dimension of the rivet shaft) that is optimized beforehand to prevent tension peaks. This preliminary design ensures that force transmission is reliably distributed across the bearing surface before loading occurs, preventing stress concentration in high-load situations.

Inventive Principle:

Principle #10Preliminary action

2Reliability

If a larger bearing surface is used, then force transmission is improved and surface pressure is reduced, but the device complexity increases

Engineering Contradiction:

Improveforce transmissionVSAvoidstructure

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The bearing surface function is merged into the rivet head itself, which is an existing component. By enlarging the bearing surface of the rivet head rather than adding a separate component, the solution improves force transmission while minimizing increases in device complexity. The rivet head serves both as the fastening element and the load-distributing bearing surface.

Inventive Principle:

Principle #5Merging (Combining)

3Reliability

If stainless steel with protective coating is used, then corrosion resistance is improved, but manufacturing cost increases

Engineering Contradiction:

Improvecorrosion resistanceVSAvoidmanufacturing cost

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The solution uses composite material construction by combining stainless steel base material with an additional protective coating layer. This composite approach provides superior corrosion resistance compared to either material alone, while the coating can be applied through standard manufacturing processes, balancing reliability improvement with manufacturing feasibility.

Inventive Principle:

Principle #40Composite materials

Data Source

PatentUS10876564B2Blind rivet nut for the connection of two components

Publication Date: 2020.12.29 BAYERISCHE MOTOREN WERKE AG

AI summary

A blind rivet nut for connecting two components by means of a screw connection includes a rivet shank. The rivet shank has an internal thread, at the axial first end of which a deformation portion configured to produce the riveted joint is arranged. At the axial second end of the rivet shank there is arranged a rivet head with a contact face that allows an adjacent component face to lie against. The supporting surface has a radial extent which is greater than or equal to 1.5 times and less than or equal to 2 times the radial extent of the rivet shank.