Optimal Design And Analysis For Electromagnet Of Multi-Point Forming Equipment

Multi-Point Forming (MPF) is a flexible manufacturing technology forthree-dimensional sheet metal parts. In MPF, the conventional monolithic die isdivided into a matrix of discrete elements. Each element's height can be controlledby computer. The forming process of sheet metal is implemented by the contoursurface of the elements group. MPF has found its extensive application fields suchas the manufacturing of the fuselage of aircraft, the hull of ship, body panels ofvehicle, city sculpture and modern architecture etc. In MPF equipment, tow manipulators are used to adjust the height of eachelement. When the manipulator are moving from one position to another, Z axesmotor in the manipulator should be disengaged from the end of element;While theheight of element need to be adjusted, Z axes motor in the manipulator should beengaged with the end of element. As a result, the electromagnet clutch need notonly proper function of clutch, but also high reliability. In this paper, a DCelectromagnet is chosen to drive the clutch. There are hundreds of elements in one MPF equipment. To adjust theseelements properly, the electromagnet needs high reliability, good static anddynamic characteristics and long stroke. At the same time, in order to improveadjusting efficiency, there are several Z axes motors in one manipulator, so thevolume of each electromagnet clutch is strictly restricted.Design of good electromagnet is very important for MPF equipmentmanufacturing. In this thesis, the finite element method is used in the static analysisof DC electromagnet. Through the research of static characteristic, electromagnetstructure and parameters optimized. And then dynamic characteristic isinvestigated in detail. Due to the analysis of electromagnetic voltage source, thecapability and stroke of electromagnet are improved. Accordingly an optimizedelectromagnet was obtained. It provides guideline for the design of clutch in MPFequipment.Main works are as following:1) Building of the finite element analysis model for electromagnet andresearch on the techniques of numerical simulation.The paper explains the basic theory of electromagnetic field. It is made up ofa series of Maxwell equation. The finite element method of electromagnetic field isintroduced. the key parameters and algorithms that have a great influence on thesimulation precision and efficiency have been studied, such as, element formulas,material models and boundary condition. And the finite element models forelectromagnet have been built.2) Optimal design of electromagnetUsing magnetic circuit method and the finite element method, importantstructure parameters and electrical parameters which have significant influence onthe capability of electromagnet have been analyzed in detail. The results are usefulfor design new such electromagnet .And then, the designed electromagnet is optimized. The capability and qualityof electromagnet is improved significantly. But the volume decreases.3) Dynamic characteristic analysis of electromagnetDynamic mathematic model of electromagnet is established based onmagnetic circuit method. And then transient simulating of electromagnet are donewith Simulink of Matlab. The electrical parameters which Influences its dynamiccharacteristic are obtained, through analyzing the dynamic characteristic ofelectromagnet.By replacing the constant electrical voltage source with a desired time variedvoltage source, the better dynamic characteristic is obtained. With, its impact andnoise level, heating of winding decrease. Also the capability of electromagnet isimproved, life-span is prolonged...