Elastic double-support variable-diameter core rod for bending aircraft engine metal conduit

Abstract

The invention discloses an elastic double-support variable-diameter core rod for bending an aircraft engine metal conduit. The elastic double-support variable-diameter core rod comprises a support storage tube, an elastic outer support and an inner hydraulic part, in the inner hydraulic part, an inner cavity of an elastic membrane is filled with liquid, the tail end of the elastic membrane is provided with an opening, the opening is connected and communicates with a liquid conveying tube through a connector, the other end of the liquid tube is externally connected with a hydraulic system, theelastic outer support is a flexible whole composed of a pull rod and an elastic net-shaped structure, the pull rod is divided into three parts, namely an elastic traction section, a straight section and a pull ring which are sequentially connected, the elastic net-shaped structure is mainly formed by connecting a plurality of layers of wave-shaped metal strip circumferences and a plurality of anti-fatigue elastic connecting pieces in a net-shaped manner, and the support storage tube is arranged outside the elastic outer support / inner hydraulic part in a sleeving mode. The elastic double-support variable-diameter core rod is variable in diameter and can adapt to machining requirements of aircraft engine metal bent tubes with different sizes, so that the production cost is reduced, and the defects of wrinkling and section flattening forming in the bending process are effectively overcome.

Description

technical field [0001] The invention relates to the technical field of design of a bending die for anti-wrinkling and anti-section flattening forming of a thin-walled elbow special for an aircraft engine, in particular to an elastic double-support variable-diameter mandrel used for bending a metal conduit of an aircraft engine. Background technique [0002] Thin-walled metal elbows are an indispensable and important component in lightweight and centralized transportation pipelines, and are especially widely used in the aerospace industry. There are a large number of ducts on an aircraft engine. In order to save space, they need to be bent into various shapes to avoid interference in a limited space. Compared with ordinary bent pipes, metal pipes dedicated to aircraft engines have thinner walls and larger bending angles. During the forming process, material accumulation and wrinkling on the inner side of the pipe are more likely to occur, and the flattening and distortion of ...

AI Technical Summary

Problems solved by technology

Its shortcomings are as follows: (1) The size of the supporting cross section is fixed, and mandrels of different diameters need to be replaced to process bends of different diameters. However, in aerospace and other application fields, large-diameter thin-walled bends are often customized as a single piece The corresponding mandrel cannot be reused, which greatly increases the use and storage cost of the mandrel; (2) The outer surface of each ball joint is actually in line contact with the inner wall of the elbow, and the large-diameter thin-walled elbow is formed It is difficult to guarantee the support effect only by line contact, and defects may still occur in the gap between two line contacts; (3) limited by the structure of the ball joint and the connection mode of the ball joint, it is difficult for the multi-ball joint flexible mandrel to bend at a large angle (90° °~180°), the core baseball joint may interfere, and avoiding interference by increasing the ball joint clearance is actually at the cost of sacrificing the bending outer support strength

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