Pin and Tie-Bolt Cold Extrusion for Material Savings
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Solution Overview
Problem
Existing methods for producing shaped pins/tie-bolts require complex machining operations and result in material wastage due to the need for initial workpieces larger than the final product, making them costly and inefficient.
Innovation Solution
A method involving a series of cold-machining steps within molds and punches to elongate and shape a solid workpiece from a smaller initial size, reducing material usage and eliminating the need for subsequent machine-tool finishing, allowing for various configurational variations and standard tool operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If traditional machining methods are used to produce shaped pins/tie-bolts, then the required configurational variations and positioning accuracy are achieved, but the production complexity and cost increase significantly
Solution Approach 1:
The patent changes the fundamental parameter of the manufacturing process from subtractive machining to additive extrusion. By using a profiling extrusion die that matches the final cross-sectional shape of the pin, the complex configurational variations are achieved directly during forming, eliminating the need for complex multi-step machining operations while maintaining manufacturing precision
Solution Approach 2:
The patent applies preliminary action by pre-shaping the workpiece in the extrusion die before final assembly. The die is designed with the exact final cross-sectional profile, so the shaping action is completed during the extrusion process itself, preparing the workpiece for immediate assembly without requiring subsequent machining or finishing operations
2Manufacturing precision
If traditional machining methods are used to produce shaped pins/tie-bolts, then the required shape and size are achieved, but substantial material wastage occurs
Solution Approach 1:
The patent fundamentally changes the material utilization parameter from subtractive to additive manufacturing. The extrusion process forms the pin directly from a cylindrical workpiece by displacing material through a shaped die, ensuring that essentially all the original material ends up in the final product with minimal wastage, while achieving the required shape accuracy
Solution Approach 2:
The patent converts what would traditionally be waste material (the excess material removed by machining) into the beneficial feature of the invention: the material is redirected through the extrusion die to form the desired shape. The compression and displacement of material that would otherwise be discarded as swarf is instead used to create the complex cross-sectional profile efficiently
3Ease of manufacture
If cold-machining extrusion is used to produce pins/tie-bolts, then material usage is reduced and production cost decreases, but the structural strength must be maintained
Solution Approach 1:
The patent changes the physical state parameter of the material during processing by using cold-machining extrusion. The workpiece is compressed and formed at room temperature, which maintains the material's inherent strength properties while achieving the desired shape. The cold working process actually increases strength through work hardening, resolving the contradiction between ease of manufacture and structural strength
Solution Approach 2:
The patent applies preliminary strengthening action through the extrusion process itself. The compression and plastic deformation during cold extrusion create work hardening in the material, which increases the pin's structural strength before assembly. This preliminary action ensures that the simplified manufacturing process does not compromise the required structural integrity
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
Enables simple, low-cost, and versatile production of strong, shaped pins/tie-bolts with significant material savings and reduced production costs, while maintaining mechanical strength and allowing for standard tool usage without specialized skills.
Implementation Method 1
closing the solid workpiece 10a inside a first mould 20b with compression of the solid workpiece
Implementation Method 2
the workpiece 10a stretches in the longitudinal direction owing to compression of the mould 20b
Data Source
Figure 1a~1f
Figure 2a~3b
AI summary
Method for producing a pin/tie-bolt (110;210) extending in the longitudinal direction (X-X), comprising the steps of: a) providing a solid workpiece (10a) made of suitable material and having a suitable length in the longitudinal direction and width/diameter in the transverse direction; wherein the length in the longitudinal direction of the initial workpiece is less than the lenght in the longitudinal direction of the finished pin/tie-bolt; c) compressing the solid workpiece (10b) inside a second mould (20c) associated with a second punch (30c) with formation of a workpiece (10c) having a length in the longitudinal direction elongated to the final desired size and with an internal longitudinal cavity (11c) having a suitable final depth; e) compressing in the transverse direction the workpiece (10d) inside a fourth mould (20e) with a longitudinally directed stretching and partial closing of the longitudinal internal cavity with formation of a workpiece (10e) which has a cylindrical top part (10f1) closed to the final desired diameter, a hollow conical connecting collar (13e) with the final size and a hollow cylindrical middle part (10f2) of larger diameter than the cylindrical top part (10f1) and with the final size.