Seamless Pipe Extrusion with Upsetting for Better Concentricity
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Solution Overview
Problem
The existing production technology for seamless pipes results in uneven wall thickness due to low concentricity, leading to a low rate of finished products that do not meet requirements.
Innovation Solution
A method involving an extruder that includes steps such as sleeving an ingot holding cylinder on an upsetting shaft, clamping an aluminum bar, moving it to ensure central alignment, upsetting, perforating, and extruding through a mold to maintain coaxial alignment and uniform thickness, with additional steps for material utilization and automation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If aluminum bars are extruded with a plug and mold using existing technology, then seamless pipes are formed, but the concentricity is low resulting in uneven wall thickness
Solution Approach 1:
The aluminum bar undergoes preliminary upsetting treatment before extrusion to pre-position it centrally within the ingot holding cylinder. This preliminary action ensures that the aluminum bar is already centered before the actual extrusion process begins, eliminating alignment issues during extrusion and achieving uniform wall thickness without requiring complex real-time alignment mechanisms.
Solution Approach 2:
The ingot holding cylinder serves as an intermediary device between the aluminum bar and the mold. It provides a centralized positioning structure that holds the upset aluminum bar in a fixed central position, mediating the alignment between the workpiece and the mold, and ensuring coaxial alignment throughout the extrusion process.
2Manufacturing precision
If the aluminum bar is directly extruded without upsetting, then the production process is simpler, but the concentricity and wall thickness uniformity deteriorate
Solution Approach 1:
The upsetting process is performed as a preliminary action before extrusion to achieve both concentricity and process simplicity. By pre-positioning the aluminum bar centrally through upsetting, the system achieves high manufacturing precision without requiring complex real-time control mechanisms during extrusion, thus balancing precision requirements with process simplicity.
3Loss of substance
If the perforating needle perforates completely through the aluminum bar, then the perforation is complete, but material is wasted and the front section becomes too solid
Solution Approach 1:
The perforating needle performs localized perforation only at the rear section of the aluminum bar rather than completely through. This local quality approach creates sufficient perforation for air entrapment prevention in the critical rear section while preserving material in the front section, achieving both material conservation and functional effectiveness.
Solution Approach 2:
Instead of complete perforation, the system applies partial perforation action that is sufficient for the required function (preventing air entrapment and ensuring complete filling) without excessive material removal. The partial perforation in the rear section provides adequate functionality while maintaining material efficiency.
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 improves the concentricity and material utilization of seamless pipes, resulting in higher quality products with uniform thickness and increased production efficiency.
Implementation Method 1
The principle is formation through metal plasticity and pressure
Data Source
AI summary
A method for producing seamless pipes and an extruder are provided, including: S1, sleeving an ingot holding cylinder on an upsetting shaft and feeding an aluminum bar; S2, moving the ingot holding cylinder backwards; S3, squeezing the aluminum bar by an extrusion plug; S4, after upsetting, moving the ingot holding cylinder and the extrusion plug back to one side away from the upsetting shaft; S5, removing the upsetting shaft and installing a mold on the mold shaft; S6, perforating the aluminum bar after upsetting by a perforating needle; S7, extruding the perforated aluminum bar by the extrusion plug. The aluminum bar after upsetting keeps the same central axis as the extruder centerline and the ingot holding cylinder. The seamless pipes extruded from the mold are uniform, thereby improving their concentricity and finished product rate.