Hole-enlarging deforming device and method for metal pipe fitting

Abstract

The invention relates to a hole-enlarging deforming device and method for a metal pipe fitting.The device comprises the metal pipe fitting, an expanding support and an expanding die and further comprises an elastic die sleeve placed in the metal pipe fitting. The internal diameter of the elastic die sleeve is in clearance fit with the external diameter of the expanding die. The method comprises following steps: firstly, installing the elastic die sleeve into the metal pipe fitting such that internal diameter of the elastic die sleeve is in clearance fit with the external diameter of the expanding die; secondly, installing the expanding support to a punch press and applying expanding pressure to the expanding die such that a calibrating strap penetrates through the elastic die sleeve and performs expanding operation, and taking down the metal pipe fitting after finishing the above steps. The method helps to avoid direct friction between the metal pipe fitting and the expanding die such that quality of an inner surface of the metal pipe fitting and size precision of the metal pipe fitting after expansion are improved. Therefore, abrasion of the expanding die is effectively reduced and durability of the expanding die is improved. The method can be extensively applied to expanding deforming of the metal pipe fitting, and process-molding of conical pipes for flow instruments in chemical and petroleum fields.

Description

technical field [0001] The invention relates to a diameter expansion deformation device and method of a metal pipe fitting, in particular to inserting an elastic mold sleeve inside the metal pipe fitting, so that the diameter expanding mold and the elastic mold sleeve may rub against each other during the diameter expansion process of the metal pipe fitting, so as to avoid the friction between the metal pipe fitting and the expansion mold. The direct friction of the diameter mold can effectively improve the inner surface quality of the metal pipe fitting and the diameter expansion device and method of the diameter expansion dimensional accuracy of the metal pipe fitting. Background technique [0002] Diameter expansion deformation of metal pipe fittings is a special cold plastic forming process. It refers to a deformation method that uses a conical mold to pass through the inner hole of the metal pipe fitting under pressure to expand the inner diameter and outer diameter of t...

AI Technical Summary

Problems solved by technology

In the existing diameter expansion method, the expansion mold 2 and the metal pipe fitting 3 will generate a large friction force during the diameter expansion process, which may easily cause scratches on the inner surface of the metal pipe fitting, and the surface quality is low. In addition, the large friction force leads to Diameter expansion is hindered, which affects the dimensional accuracy of metal pipe fittings 3 after diameter expansion

Molds are susceptible to damage due to friction

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