Accurate extrusion mould and method of light alloy stepped workpiece

Abstract

The invention relates to an accurate extrusion mould and method of a light alloy stepped workpiece. The accurate extrusion method of the light alloy stepped workpiece is characterized by comprising the following steps of: processing a convex crossed guide on a convex mould part and a crossed guide groove on a concave mould part, wherein the convex crossed guide is matched with the crossed guide groove; retaining the thickness of a step shape on a preformed planar blank; and filling metal into a cavity part, which is arranged on the side wall of the cuspidal edge and closed angle stepped surface of a convex mould or a concave mould and is provided with a groove used for metal flow in a vertical direction, by adopting a flow direction sequence control method so as to achieve the purpose of the formation of a cuspidal edge and closed angle step of the workpiece; and placing isopyknic blanks into the concave mould by adopting primary heating: a. prepressing by using a prepressing mandril, and b. finally forming by using the convex mould. The accurate extrusion module and method provided by the invention have the advantages of high utility ratio of materials, short manufacturing process, high accuracy and efficiency, low cost, and the like.

Description

technical field [0001] The invention belongs to the metal extrusion forming technology, specifically a stepped shape used in a wide range of light alloy forming fields, with high dimensional accuracy, deformation temperature in the alloy recrystallization temperature range, and shape transition sharp corrugated sharp corners Precision extrusion dies and methods for workpieces. Background technique [0002] At present, for the forming of stepped workpieces, a single step is usually formed by multiple sets of convex and concave dies and multi-pass extrusion, and after repeated heating and extrusion, the step by step is gradually formed to form a step. There are many processes and a large number of moulds, especially when there is a placement error caused by placing the blank in the upper pass to the lower pass mold, resulting in low dimensional accuracy, and the mold is often scrapped in advance due to uneven force, regardless of forging die or extrusion die Under high temper...

AI Technical Summary

Problems solved by technology

[0003] 1. There are two types of guiding mechanisms for traditional extrusion molds: lock buckles and mold bases with guide pillars and guide sleeves. The former has low guiding precision and high strength, but the guiding precision is as low as 0.5-2mm. It is used for extrusion dies and forging presses. The guide post and guide sleeve formwork for the forging die have high precision but cannot work at high temperature and have low strength. When the forming die is isothermally formed, high guiding precision, high horizontal bending strength and high temperature resistance are required. The traditional guiding mechanism cannot meet the requirements

[0004] 2. Multi-pass extrusion is used for the traditional stepped shape, which has many procedures and low efficiency. The inner and outer fillets R1-R5 of the stepped workpiece are extruded, and the material is prepared according to the same volume. The blank is subjected to three-dimensional stress from the flow channel through the flow hole. , the cavity will not be filled by the blank material, because the material will flow turbulently from the flow channel into the cavity, resulting in folding or lack of meat, the sharp edge shape of the side wall of the cavity will not be filled, and the workpiece will be corresponding after demolding position forms rounded corners

At the same time, due to the offset and inaccurate position every time the blank is placed, there must be an alignment process, which is time-consuming and labor-intensive, and the efficiency is low, and it is easy to form multi-layer twists and step shapes (the step type has many single processes)

[0005] 3. In traditional extrusion, the inner and outer rounded corners of stepped shape extrusion are not less than R1~R5, and it is difficult to achieve a rounded corner smaller than R0.5. If it is to meet the requirement of less than R0.5, the side wall must have a slope of 1°~15° draft degree; if the internal and external fillets in the stepped shape must meet the conditions of less than R0.5 and the side wall is a straight wall, the traditional extrusion process cannot be completed (the fillet radius is large)

Images