Multi-convex die step-by-step reverse extrusion forming method

Abstract

The invention relates to a multi-convex die step-by-step reverse extrusion forming method. A multi-convex die is composed of an inner convex die and an outer convex die, and steps of discharging, blank making, step-by-step reverse extrusion and subsequent processing are included. The multi-convex die step-by-step reverse extrusion forming method is characterized in that according to step-by-step reverse extrusion, the inner convex die and the outer convex die are used for extruding blank metal at least once, the blank metal generates flow deformation under the action of the multi-convex die, the stroke of the inner convex die and the outer convex die is controlled to obtain a hollow member with the bottom being the solid flat bottom or concave bottom or convex bottom. According to the multi-convex die step-by-step reverse extrusion forming method, in one die, forming manufacturing of the hollow parts with the flat bottoms, the convex bottoms, the concave bottoms and the like can be achieved; and the extrusion forming contact area is reduced, the extrusion forming force is reduced, and the amount of extrusion deformation can be improved.

Description

technical field [0001] The invention belongs to the extrusion method of metal materials, in particular to a kind of reverse extrusion forming of large hollow parts with flat bottom, convex bottom and concave bottom, which are circular in cross-section, and is suitable for cold, warm and cold extrusion of metal materials. Hot extrusion. Background technique [0002] Extrusion process, as one of the processes for the production of non-ferrous metals and steel materials and the forming of parts, is an advanced manufacturing method in modern metal plastic processing. Extrusion as a secondary plastic processing is mainly used in the production of parts. As a kind of extrusion process, reverse extrusion is mainly suitable for the manufacture of hollow parts with round, multi-layered round, square, rectangular, etc., and the bottom is solid or with holes, and flat bottom, concave bottom or convex Bottom and other hollow parts have been widely developed and applied. [0003] For ...

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Problems solved by technology

[0007] (1) The forming force is large, and the multi-integral punch is used to increase the closing height of the mold. When the nominal pressure of the press and the opening height are constant, the size of the hollow part that can be formed is limited;

[0008] (2) For hollow parts with solid convex bottom and concave bottom, multiple back-extrusion or cutting after back-extrusion will result in many forming passes and low material utilization rate;

[0009] (3) The applicability of the process is poor. When the shape and size of the extrusion punch are determined, only workpieces of a specific shape and size can be formed. The applicability of the process, poor mold versatility, and high production costs

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