Bar Pin Cold Forming With Closed Apertures in One Die Stroke
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Solution Overview
Problem
Existing manufacturing processes for bar pins in bushing assemblies are time-consuming and costly due to separate steps of forging flats and drilling holes, necessitating an improved and streamlined process.
Innovation Solution
A method involving cold heading or forging to deform a slug of metal into a bar pin with slotted ends, defining semi-cylindrical surfaces that serve as finalized finished surfaces, and radially inwardly deforming legs to create closed apertures, eliminating the need for additional machining steps.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If separate steps of forging flats and drilling holes are used, then manufacturing precision is improved, but productivity deteriorates
Solution Approach 1:
The patent combines multiple separate manufacturing operations (forging flats, forming slots, creating closed apertures) into a single integrated cold heading process. The die simultaneously performs all these operations on the metal slug in one stroke, eliminating the need for separate forging and drilling steps while maintaining geometric precision through the integrated tooling design.
Solution Approach 2:
The die is designed to pre-form the metal slug with the final geometry including closed apertures during the initial cold heading operation. The slots are formed and legs are positioned in advance, then the same die performs the final deformation to close the apertures, eliminating subsequent machining operations.
2Manufacturing precision
If separate machine operations are used for forming flats and holes, then manufacturing precision is improved, but loss of time increases
Solution Approach 1:
The patent merges multiple sequential operations (flat formation, slot cutting, aperture drilling) into a single simultaneous die operation. The cold heading die performs all formative operations in one stroke, eliminating transfer time between machines and setup time for separate operations while maintaining dimensional accuracy through precision die design.
Solution Approach 2:
The cold heading process continuously deforms the metal slug through a single uninterrupted forming action. The die closes on the slug and performs all necessary deformations (flattening, slot formation, aperture closing) in one continuous motion, eliminating idle time between separate operations and maintaining continuous useful action throughout the manufacturing cycle.
3Productivity
If integrated deformation and aperture formation is used, then productivity is improved, but device complexity increases
Solution Approach 1:
The die is segmented into distinct functional zones, each responsible for a specific operation: one zone forms the flats, another zone creates the slots, and a third zone closes the apertures. This segmentation allows each zone to be optimized independently while working simultaneously, managing complexity through functional division rather than requiring a monolithic complex tool.
Solution Approach 2:
The die operates in multiple spatial dimensions simultaneously, deforming the slug radially inward to close apertures while also forming flats and slots in different orientations. By utilizing multi-axial deformation capabilities, the die performs multiple operations that would otherwise require separate sequential steps, improving productivity without proportionally increasing complexity.
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 reduces manufacturing time and costs by integrating deformation and aperture formation into a single process, ensuring precise and efficient production of bar pins with closed apertures.
Implementation Method 1
A method of manufacturing a bar pin includes cold heading, forging or otherwise forming a pin
Implementation Method 2
deform the slug to define first and second legs on a first side of the central portion and deforming the slug to define third and fourth spaced apart legs
Implementation Method 3
the first and second legs are radially inwardly deformed to define a first closed aperture
Data Source
AI summary
A method of manufacturing a bar pin comprises positioning a slug of metal in a die and advancing a tool within the die to deform the slug and form a central portion of the bar pin. The slug is deformed to define first and second legs on a first side of the central portion and deforming the slug to define third and fourth spaced apart legs on a second side opposite the first side. The method further includes defining a finalized finished first surface having a semi-cylindrical shape and interconnecting the first and second legs. A finalized finished second surface having a semi-cylindrical shape is defined and interconnects the third and fourth legs. Subsequent to the defining steps, the first and second legs are radially inwardly deformed to define a first closed aperture. Optionally, the third and fourth legs are radially inwardly deformed to define a second closed aperture.