| Improving the efficiency of the production of parts and enhancing parts’performance are the goal and developing trend of modern advanced manufacturing technology. Sheet metal forming is a very important plastic forming technology, which has been widely used in industrial production.During the processing of sheet metal forming,Blank Holder Force(BHF) is a key factor that affects forming quality, therefore the control system of BHF are always the focus.This article is on the basis of the single-action hydraulic press,hydraulic mold is designed to achieve the non-uniform blank holder, to reasonable control of the points of the BHF,to enable it to reach process requirements of the sheet metal deep drawing. The main content of the paper is:(1) This paper generally describes theVBHF forming technology and its development, current status and practical application on the basis of referring to a number of literatures home and abroad.The same time, the paper detailed analysis of principles and characteristics of the box drawing and introduct the several drawing experimental program.(2) According to the requirements of non-uniform blank holder, the overall structure of hydraulic mold is given.The analysis of hydraulic which is used in BHF control system of sheet metal forming is also demonstrated,including the analysis of hydraulic feature,the analysis of hydraulic circuit,determination of key parameters and type selection of key elements.(3) Combined with the characteristics of the BHF hydraulic system, Fuzzy-PID is used in accurate control of BHF. Based on study of PID and fuzzy algorithms,BHF fuzzy-PID controller is designed in detail and a fuzzy PID controller is edited in the Matlab software.(4) After entire non-uniform blank holder Hydraulic mold system is completed, mathematical model of the entire hydraulic control system is found.Last,simulation is done in MATLAB/Simulink,which proves the control system works perfectly. |
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