Square Tube Swaging with Collapsible Mandrel
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Solution Overview
Problem
Existing methods fail to effectively reduce the dimensions of multi-sided metal tubes, such as square tubes, without causing buckling, which renders them unusable for connecting longer structures due to instability in connections.
Innovation Solution
A collapsible or tapered mandrel is used internally to prevent buckling during swaging, combined with external compression dies applying significant hydraulic pressure to reduce the tube's dimensions uniformly, allowing for easy removal of the mandrel after the process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If external compression force is applied to reduce tube dimensions, then the tube size is reduced, but the tube walls buckle and become unusable
Solution Approach 1:
A mandrel is introduced as an intermediary element inside the tube to support the tube walls during compression. The mandrel prevents the walls from buckling inward while external compression forces reduce the tube dimensions. After swaging, the mandrel is removed, leaving the tube with its reduced dimensions and maintained structural integrity.
Solution Approach 2:
The mandrel provides an opposing internal force that counteracts the external compression force. This counterbalancing action prevents the tube walls from collapsing during the swaging process, allowing dimensional reduction while maintaining wall stability.
2Stability of the object's composition
If a solid mandrel is used to prevent buckling, then tube wall stability is maintained, but the mandrel is difficult to remove after swaging
Solution Approach 1:
The mandrel is designed with collapsible or telescoping sections that allow it to change its configuration. During swaging, the mandrel maintains its expanded form to support the tube walls. After swaging is complete, the mandrel can be collapsed or contracted, facilitating easy removal from the swaged tube end.
Solution Approach 2:
The mandrel is divided into multiple collapsible sections that can be compressed or telescoped relative to each other. This segmentation allows the mandrel to transition from a rigid support structure during swaging to a compact, easily removable form after the process.
3Manufacturing precision
If external compression is applied uniformly, then tube dimensions are reduced uniformly, but the flat sides of multi-sided tubes buckle
Solution Approach 1:
The mandrel acts as an internal intermediary that distributes compression forces uniformly across all surfaces of the tube, including the flat sides. By providing internal support, the mandrel prevents the flat sides from buckling while allowing uniform dimensional reduction to occur.
Solution Approach 2:
The mandrel allows the compression parameters to be applied uniformly throughout the tube cross-section. By maintaining internal support pressure, the mandrel enables the flat sides to withstand the compression forces without buckling, achieving uniform dimensional reduction.
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 enables precise reduction of tube dimensions without buckling, facilitating stable connections and easy removal of the mandrel, thus enhancing the structural integrity and assembly of longer structures like communication towers.
Implementation Method 1
A collapsible or tapered mandrel is used internally to prevent buckling during swaging
Implementation Method 2
combined with external compression dies applying significant hydraulic pressure to reduce the tube's dimensions uniformly
Implementation Method 3
external compression dies applying significant hydraulic pressure to reduce the tube's dimensions
Data Source
AI summary
An apparatus and method for swaging a square or rectangular tube, the apparatus including a support for external dies, both surface dies and corner dies, which when actuated, apply pressure to the outside of a tube to achieve its swaging to a lesser dimension, and having a collapsible mandrel located therein, supporting internal dies, that apply a lesser pressure against the interior of the tube, during a swaging operation, to assure that wall buckling does not occur. An internal die with its removing tool may locate within the end of the tube to be swaged to cooperate with the pressure from the external dies to swage the tube without any final buckling.