Bellows Expansion Joints And CAD Technique

Bellows expansion joints is a piping connect component installed to metal tube. It has hot compensating and gentle conjunction etc. function. The software takes Visual Basic6.0 as work flat, adopting ActiveX technique, transfers AutoCAD2000 painting orders from the exterior of VB through programme method. It is a re-exploitation software to design bellows expansion joints. The software adopts EJMA, the current international widespread trade standard, as mathematics model.This article introduces the designs of commonly used bellows tube and the optimization designs of bellows tube aim at economizing the material cost. Some parameters acquired from experience curve can be borked out by Lagrange linearity insert method. Considering the mechanics capability of the material is different and the molding tool size with the bellows tube is relatively fix under the different temperature and different pressure, the software established the corresponding database. In VB, to bind-control binds data-control and database together, it can visit the database of FoxPro 3.0, realizing some operations such as record, delete, search and modify. The software can save and output design book.This article discusses how to establish the standard gallerys in CAD, how to establish the basic parameter database for the size of each spare parts and some calculating formulas relating to component size in VB. Through establishing graph root objects and accroding to certain regulation, it transfers painting orders sealed in the CAD and paints the production diagram paper of bellows expansion joints, and through establishing to printing environment to completes the print of diagram paper.This software has the Object-Oriented Programming and configuration program design idea. It has the error-correcting function and is convenient to use. The user just inputs basic parametes at simple screen prompt and the software can realize auto output of production diagram paper. The whole software can realize the every kinds of bellows design of the U-type , the enhance U-type and the Ω -type. The software can realize diagram paper design of over ten thousand kinds of specification of U-type expansion joints and the design range is DN25-1000mm, low pressure and middle pressure, with compensating value smaller than the300mm. The bellows expansion joints worked out have past the test and the spot usage examination .The function is dependableand the designing is reasonable.