Research On The Forming Quality Analysis And Control Of Conventional Spinning

The application in the thin-wall rotational part of multi-pass conventional spinning is more and more widely as it has high material utilization ratio, good surface quality and wide range of parts. Meanwhile as the development of industry is fast, the forming quality requirement of conventional spinning part is higher and higher. In this paper, regarding forming quality of conventional spinning as the major research object, the roller and its path were researched by using MARC finite element software. And on this basis, experiment was carried out to get the influence law of the different process parameters(elevation angle of first pass, initial position of first path, feed rate) on products’ quality in the process of multi-pass conventional spinning. The main contents and conclusions are as follows:1. Connecting with the production experience, some common defects(wrinkle, fracture, bottom bulge, orange peel, indentation, springback, excessive reduction) were analyzed and the corresponding prevention measures were put forward. Then forcing on the problem of thickness reduction, the limitation of roller path was analyzed. Basing on the analysis, roller path which is beginning from middle of blank and composite surface roller should be used in the multi-pass conventional spinning. And the feasibility was analyzed in theory.2. By means of MARC finite element software, the roller path which is beginning from middle of blank and from bottom of blank, and different surface kinds of rollers were used in the conventional spinning to study the law of equivalent stress, strain and wall thickness distribution during the spinning process. Then the better method of improving thickness distribution could be got. The simulation results showed that the maximum value of equivalent stress, strain can be smaller when the path which is beginning from middle of blank was used in the first path. It also can improve the thickness distribution and decrease thickness reduce ratio. The simulation results of rollers showed that using R25-12 roller in the conventional spinning had the best effect to decrease thickness reduce ratio.3. The experiment containing the roller path beginning from middle of blank, composite surface roller and unequal path space was carried out, the result shows that the thickness of part can be improved by using these factors. Basing on this result, orthogonal experimental method was used and the ovality, straightness and wall thickness reduction ratio were taken as indexes to analyze the influence law of the different process parameters(feed rate, the initial position of first path, the elevation angle of first pass). The result shows that the influence sequence of the reduction ratio is: elevation angle of first pass> initial position of first path> feed rate. The influence sequence of ovality is: feed rate> initial position of first path> elevation angle of first pass. The influence sequence of straightness is: feed rate> elevation angle of first pass> initial position of first path.4. The results of orthogonal experiment were taken as data sample, the optimization algorithm of ‘ SVM(Support Vector Machine)+GA( Genetic Algorithm)‘ are integrated to optimize the process parameters which would influence the thickness of conventional spinning, the thickness reduction ratio was lowered to 16.22%, this result was basically identical to the verification test. After the optimization, the parameters were: the elevation angle of first pass was 52°, initial position of first path was 0.5, and feed rate was 2.28 mm /r.