| Sheet metal forming technology is more and more important in manufacuringindustry of modern society, in order to enhance the enterprise’s competitiveness, itneeds to constantly improve the forming device and optimize process parameters tomeet the needs of the high quality forming parts. Conical cylinder is a common tube,it widely used in machinery industry, aerospace, petrochemical, transportation,construction and other fields. The forming method of traditional conical cyclinder ismainly through the hammer knock or section bending forming. The above twomethods have low production efficiency, high labor intensity, work environment noiseand low forming precision, they are not suitable for the needs of the development ofmodern society. The forming parts quality is poorer and the yield is low usingroll-bending partition method with the ordinary roller machine, it is difficult to adaptto the development of modern demand. In order to seeking efficient and fast effectiveforming method, this paper adopts three cone roller bending forming technology, itsolves the key problems of common round speed on both ends of the roller using theordinary roller machine, and different specifications conial parts can be formed.Compared with the traditional way of forming, the forming technology is more easyto control, get a higher forming precision and obtain better forming quality.The geometric model is set up between cone rolls and blank,it needs to satisfycertain geometric relationships in the process. The finite element model of the processof bending with conical rolls is construted by simulation software, the model parts andboundary conditions need to reset based on different technology parameters. Theresults of simulation should be processed and sum up the change rule of differentparameters and formed parts size. At the same time, the influence of differenttechnology parameters for forming force between conical roll and blank are analysed,it provides a theory foundation to design and optimize of technology parameters fornew equipment. In this paper, the main research contents and conclusions are asfollows:1.It mainly discusses the forming principle of roll bending, three kinds ofexpressions of the stress tensor, the material yield criterion in the process ofdeformation, the elastic-plastic material constitutive equation and finite elementsoftware of display and implicit algorithm. 2.It expounds on the geometric relationships of the major parts of the cone rollerbending forming and the geometric equation to satisfy, many steps are introduced inthe process of finite element modeling, it concludes material model, the division ofgrid cell, boundary conditions and the contact and friction and so on. It brieflyanalyzes a instance and discusses the distribution of stress and forming force.3. It discusses the influence of related technology parameters that conclude pressdisplacement, center distance of outer rolls, plate thickness and friction coefficient,and sum up the change rule of different parameters and formed parts size. The resultsshow that the curvature radius of big and small circle decrease with increasing ofpress displacement, decreasing of center distance of outer rolls and increasing of platethickness, the formed parts come out dislocation phemomenon with the increase of thecoefficient of friction, and the simulation results indicate that a friction of0.3issufficient for bending a good formed part.4.It discusses the influence of related technology parameters for forming forcethat conclude press displacement, center distance of outer rolls, plate thickness, platewidth and materical, and sums up the change rule of different parameters. The resultsshow that forming force continues to increase with increasing of press displacement,decreasing of center distance of outer rolls, increasing of plate thickness, increasingof material yield stress and increasing of plate width. The research results haveguiding significance to design and optimize of structure for new bending equipment. |
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