Hollow Fastener Attachment to Composite Materials
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Solution Overview
Problem
Existing methods for attaching hollow elements like rivets or nut elements to composite materials, such as fiber-reinforced plastics, often result in material weakening and waste due to drilling or punching, which are time-consuming and costly, and do not provide loss-free holes.
Innovation Solution
A method using a hollow element with a flange and shaft part, combined with an auxiliary tip that progressively pierces the material to create a hole, displacing material laterally and accumulating it in grooves or undercuts for reinforcement, thereby creating a secure attachment without significant weakening.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If drilling or punching is used to create holes for fastener elements, then holes can be provided in composite materials, but material residues or waste arise and the composite material is weakened in the region of the bore
Solution Approach 1:
The patent replaces traditional mechanical drilling or punching processes with a heating-based system. A heating element is inserted through the hollow fastener element to melt the matrix material, creating a hole without mechanical contact. This substitution eliminates material residues and waste while preserving the composite structure.
Solution Approach 2:
The invention utilizes the phase transition of the matrix material from solid to liquid state through localized heating. The matrix material melts around the heating element, allowing the hollow fastener element to be inserted through the softened material without mechanical cutting, thereby avoiding material loss and structural weakening.
2Ease of manufacture
If drilling or punching is used to create holes, then holes can be provided for fastener elements, but the composite material is weakened in the region of the bore
Solution Approach 1:
The patent replaces mechanical drilling or punching processes with a heating-based system. A heating element is inserted through the hollow fastener element to melt the matrix material, creating a hole without mechanical contact. This substitution eliminates material residues and waste while preserving the composite structure.
Solution Approach 2:
The invention utilizes the phase transition of the matrix material from solid to liquid state through localized heating. The matrix material melts around the heating element, allowing the hollow fastener element to be inserted through the softened material without mechanical cutting, thereby avoiding material loss and structural weakening.
3Reliability
If threaded inserts or eyes are integrated into the plastic component during manufacture, then fastener elements can be attached, but the process is very time consuming and complicated and leads to further costs
Solution Approach 1:
The hollow fastener element is pre-assembled with the heating element before the attachment process. This preliminary preparation allows the entire attachment operation to be completed in a single step during component assembly, eliminating the need for separate operations to create holes and install fasteners, thereby reducing manufacturing time and complexity.
Solution Approach 2:
The heating element serves dual purposes: it creates the hole through thermal melting and simultaneously facilitates the insertion of the hollow fastener element. The process is self-contained within the attachment operation itself, requiring no additional manufacturing steps or complex tooling.
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 allows for the creation of substantially loss-free holes with minimal material weakening, providing a secure attachment and preventing fatigue cracks, while also forming a planar screw-on surface, thus enhancing the structural integrity of the composite material.
Implementation Method 1
heating the component 130 in the region to be pierced to a temperature at which the matrix material of the composite material softens or becomes pasty
Implementation Method 2
the tip progressively pierces the component and increasingly displaces the material of the component towards the outside around the point of first penetration
Data Source
Figure 1A~1B
Figure 1C~1E
Figure 2A~2E
AI summary
A hollow element such as a hollow rivet or a nut element for attachment to a component consisting of a composite material such as a fiber reinforced plastic part or a fabric reinforced plastic part is presented. The element has a flange part and a shaft part extending away from the flange part and/or a rivet section, wherein the rivet section, if present, can also be formed at the free end of the shaft part, with the a hollow element furthermore having a central passage, which is optionally provided with a thread cylinder. The hollow element is used in combination with an auxiliary tip which is either inserted from the flange side of the element through the passage, or from the side of the free end of the shaft part of the rivet section into the passage, such that a conically converging region of the auxiliary tip projects from the free end of the shaft part or of the rivet section. The free end of the hollow shaft part of the element, or the free end of the rivet section, has a conically converging form which is matched to the conical shape of the auxiliary tip that is used.