Research On Design And Implement Of A Pressure-Time Curve Controlled Superplastic Bulging System

Superplastic bulging is a typically application for superplastic forming of a blank of material into a part. It is similar to blow molding and vacuum forming. Developing advanced automatically controlling apparatus is very important both in further research and production application.This paper provides a method and apparatus for automatically controlling the pressure based on the pressure-time relationship during superplastic bulging. The method is constituted of three parts: determining relationship between time and pressure system by FEM and numerical simulation, automatically controlling pressure system and data exchanging system. Based on this method, a brand new superplastic bulging apparatus is developed with Programmable Logic Controller and computer. PLC is used as main control unit to automatically control the pressure in accordance with the previously determined relationship between time and pressure during the part is formed. Computer is used to deal with data-processing and data-transmission. Data are exchanged between them through RS-232 serial communication. This apparatus will be suitable for many kind of Superplastic Bulging.This paper mainly discusses three aspects. Firstly, based on the theory of engineering cybernetics and the working of PLC, the project of the system composing and controlling are determined. Then, on the basis of the function demand of the system, the parts of the system are selected and the programs are designed. At last, the system is established with the parts and the programs are tested.