| In recent years our country roof accidents and roof caving accidentsaccount for34.66%in the coal mine accident death, thus it can be seen that thesafety and reliability of the mine roadway support problem is still tricky.Original supports, such as beams, flat strip steel and steel ladder beam, are tooexpensive, or their strength is insufficient, so they can not meet the needs ofmining under assignments. W steel belt, as a kind of new structure material, hasstrong bending performance. It not only reduces the support cost and has theadvantages of saving support steel, but also has strong bending performance inthe roof rock of incomplete application effect than beam, flat strip steel andsteel ladder beam. As W steel belt is widely used in the mine roadway support,it put forward the high quality and highly efficient production. The requirementof the research in the molding process and the development of new equipmentare becoming more and more important.By analyzing the research status of roll forming technology at home andabroad, and according to the basis of the existing equipment, the W steel beltroller bending process technology is analyzed, and identified the W steel beltforming for roll forming process and finally confirmed by calculation of roll curve for nine times, including the first time the forming roller leveling roller,the last time the forming roller for bending of guide roll. Bending angle isselected considering the characteristics of material and product performance,and the choice of roller spacing, bending method before and after, thecalculation of blank width and so on are made according to the theory.To solve the problem of continuous production of W steel band, dynamicshear punching device is designed based on the characteristics of W steel beltproduction. When the strip length of punching shear or length is met,compaction mechanism hold down the steel belt, synchronize the car with steelbelt, punching institution or shearing mechanism, when punching shear iscompleted, pressure institutions loosen the steel belt, then the car is back to theoriginal position. Each institution by proximity switch action is the beginningand end of the input signal to PLC, PLC output signal controls variouselectromagnetic valve movement, so as to control the hydraulic cylinder motion.Finally the action time of each hydraulic cylinder is calculated, and therelationship between the maximum speed of steel strip running and theminimum steel belt length is obtained.Based on nonlinear finite element software Marc, W steel belt model isestablished. Through the analysis of simulation results, the equivalent plasticstress and strain of W steel belt roller bending deformation of parts, steel beltwidth changes in the process of deformation, and the influence of frictioncoefficient for roller pressure is obtained, then the steel strip shape after rebound is analyzed.Finally aiming at the problems existing in today’s technology, this paperputs forward the new technology for W steel belt forming, through thesimulation results validate the rationality of the process. The process has asmall steel belt tensile deformation and roller bearing, and has got good effectin the practical production. |
PDF Full Text Request