Hydraulic forming technology of tube blank of small-sized corrugated tube and forming die sheet special for tube blank of small-sized corrugated tube

Abstract

The invention discloses a hydraulic forming technology of a tube blank of a small-sized corrugated tube. The hydraulic forming technology comprises the steps that firstly, a forming die is installed well, the forming die comprises a lower sealing cover, a forming cushion block, a forming die sheet, a forming cushion block and an upper sealing cover from bottom to top, an unformed tube blank of the small-sized corrugated tube is placed in the die, and the die is sealed; the upper sealing cover and the lower sealing cover are pressed tightly, and hydraulic oil is injected into the unformed tube blank until space defined by the upper sealing cover, the inner wall of the tube blank and the lower sealing cover is filled with the hydraulic oil; a forming press conducts pressurization continuously, the tube blank deforms and bulges due to the influence of pressure, and then pressure is released; the forming cushion block is detached, pressurization is conducted, a main oil cylinder of the forming press advances, and after the two ends of the tube blank of the corrugated tube are flanged and deformed, pressure is released; finally, the forming die sheet is replaced with a thin cushion block, pressurization is not conducted, the main oil cylinder of the forming press advances, and then deformation of the middle corrugated portion of the tube blank of the corrugated tube is completed; after the above steps are completed, the forming die is detached, and the formed tube blank of the corrugated tube is taken out.

Description

technical field [0001] The invention relates to a hydroforming process, in particular to a hydroforming process for a small corrugated pipe blank with small wave depth and short single wave expansion length and a special forming mold piece. Background technique [0002] Half of the difference between the length of the outer diameter and the length of the inner diameter of the bellows is the wave depth, and the length of the corrugations between adjacent wave troughs after fully stretching is a single wave expansion. Such as figure 1 As shown, the ordinary corrugated pipe has a large wave depth and a long single wave expansion length. When the traditional hydroforming process is used to process the tube blank, it requires less pressure and is easy to bulge, so it is easy to form during processing. Ordinary corrugated pipes mostly adopt the multi-wave one-time molding method. After adjusting the relative position of the mold and the pipe blank, pressurize the inner cavity of ...

AI Technical Summary

Problems solved by technology

like figure 2 The shown small bellows has a small wave depth and a short single-wave expansion length. Generally, the single-wave forming process is used, but when encountering a bellows with a small absolute size, it will be difficult to achieve the ideal if the traditional hydroforming process is used. processing effect

First of all, it is necessary to use a forming die with extremely thin thickness; secondly, the tube blank is not easy to deform and bulge after being pressed because the length of the single wave expansion is too short; finally, because the wave depth is too small, the forming accuracy of the processed tube blank cannot be guaranteed.

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