| Traditional machine manufacturing has a long history, which plays an important role in production and material civilization in the world. With the continuous development of science and technology, traditional machine manufacturing brings great change towards advanced manufacturing technology. Future advanced manufacturing technology is developing into sophistication, flexibility, intellectualized, integration and globalization. Precise forming, a main part of advanced manufacturing technology, includes net shape cast form, precision plastic form, precision joining, precision heat treatment, surface modification etc. It is a comprehensive technology of new technology, new material, new equipment etc. At present precise forming technology has fulfilled near net shape towards a great extent, and its goal is net shape.According to billet's characteristic, metal plastic forming may be divided into bulk forming and sheet forming, and each forming has many processing methods. During the course of the design of forging technology, usually the forging envelope and forged piece drawing are determined by part drawing, and so forged piece weight and size of blank are computed according to the size of forged piece (including flash). If forged piece is complicated, it will take time and arduous, and liable to make a mistake compared with the conventional computing method. Billet size of forged piece and plate work piece with complicated shape are often confirmed by many die settings, so its cost is high. The similar problem on computing blank size also exists in sheet forming, such as spreading size of bending piece, blank size of axial symmetry parts by deep drawing. To solve the problem, the surface area of workpiece is needed to be computed and blank size is determined according to the principal of Equal Square. But it is hard to compute, even some applied and credible empirical formulas have been given in lots of literatures.It is well known that the determination of billet dimension is very important for saving material, reducing cost and increasing economic benefit. And as for the closed die forging, billet size will affect the process directly. But the main purpose of this thesis is to ascertain the relation of volume change with technology in different working procedures of bulk forming and sheet forming, and the whole or part volume change of complicated shape billet should be measured, which is an urgent problem of plastic forming.The thesis is an important component of overall research about instrument, meters and measuring technique of superplastic and plastic precise forming which is researched by my supervisor, Professor Song Yu Quan, and also a part of Key technologies R&D Programme"New equipment and new technology on rolling plastic precision forming of automobile connecting rod" assumed by superplastic and plastic research institute of Jilin university. According to his two patents, "the Volume measuring instrument of arbitrary shape workpiece" and "the area measuring instrument of arbitrary shape sheet part", this thesis mainly solve the following problems: instrument for measuring the whole and local volume of the pieces with arbitrary shape and fulfilling collection of corresponding control data and design of processing system; instrument for measuring the area of the sheets with arbitrary shape and collection corresponding control data and designing processing system; explaining the value of measuring bulk and area during plastics precise forming.The area measuring instrument of arbitrary shape sheet part belongs to the field of instrument and meter measurement of modern sheet forming, which consists of mainframe, control system, measuring system, detection system, data processing system and result displaying or printing system. The instrument can measure the square and density of arbitrary complicated shape blank. The measuring method is as follows: hang the blank in the air, the weight of blank is displayed on the screen and then immerge it into the water and the square and...
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