Thickened Wall Fastener Stamping Method
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Solution Overview
Problem
Fasteners, such as flange nuts, often suffer from mechanical weakness and limited applicability due to contact corrosion when used with non-compatible materials, restricting their usage.
Innovation Solution
A method involving multiple stamping processes using successive dies to reduce the diameter and top radius of a non-ferrous blank, resulting in a work piece with a thickened wall, enhancing structural strength and corrosion resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If fasteners are made from similar materials to avoid contact corrosion, then corrosion resistance is improved, but mechanical strength and applicability are reduced
Solution Approach 1:
The patent applies composite materials by combining a non-ferrous base material with a ferrous overlay layer. The non-ferrous material (such as aluminum or copper alloy) provides corrosion resistance, while the ferrous overlay layer (applied through processes like explosion bonding or cladding) provides enhanced mechanical strength. This composite structure allows the fastener to achieve both corrosion resistance and mechanical strength simultaneously, resolving the contradiction between these two properties.
2Strength
If the wall thickness of the fastener is increased to improve mechanical strength, then strength is improved, but manufacturing complexity and material usage increase
Solution Approach 1:
The patent applies local quality by creating a thickened wall structure at specific critical locations of the fastener rather than uniformly increasing wall thickness throughout. The forming process selectively thickens the wall in areas subject to high stress or corrosion, such as the shank or thread region, while maintaining thinner walls in less critical areas. This localized approach improves mechanical strength where needed without significantly increasing overall material usage or manufacturing complexity.
3Strength
If multiple successive stamping dies are used to reduce diameter and thicken walls, then mechanical strength is improved, but manufacturing time and process complexity increase
Solution Approach 1:
The patent applies segmentation by dividing the forming process into multiple successive stamping operations, each using a dedicated stamping die that performs a specific function. The first stamping die creates the initial cup-shaped feature, while subsequent stamping dies progressively reduce the diameter and thicken the wall at different stages. This segmented approach allows each die to be optimized for its specific task, improving overall process efficiency and mechanical strength while managing manufacturing time through systematic progression.
Solution Approach 2:
The patent applies preliminary action by performing intermediate forming operations that prepare the workpiece for subsequent critical forming steps. The successive stamping dies progressively pre-thicken the wall and reduce the diameter in controlled stages, creating an optimized intermediate structure that facilitates the final forming operation. This preliminary action ensures that material flow and stress distribution are optimized throughout the process, reducing the risk of defects and improving final mechanical strength.
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 method produces fasteners with increased mechanical strength and wider applicability, as the thickened wall reduces stress concentration and enhances resistance to contact corrosion, allowing use with dissimilar materials.
Implementation Method 1
stamping the blank a first time using a first stamping die to draw a portion of the blank into a cup-shaped feature
Implementation Method 2
stamping the blank a plurality of additional times using a plurality of successive stamping dies to reduce the diameter of the cup-shaped feature and to reduce the top radius
Implementation Method 3
reforming the cup-shaped feature having the second diameter at a forming station to a formed shape having a thickened wall
Data Source
AI summary
The present disclosure provides a method for manufacturing a work piece, such as fasteners or flange nuts. The method produces a work piece with a thickened wall. This can be accomplished using a plurality of successive stamping dies to reduce the diameter of a cup-shaped feature drawn from a blank, and reforming the cup-shaped feature to a formed shape having a thickened wall. A fastener or flange nut with a thickened wall manufactured by stamping and forming is also disclosed.