Research On The Process Parameters Of The Four-roll Plate Bending Machine

In this paper,the effect of process parameters of the four-roll rolling plate on the rolling process is studied.Based on the structural parameters of W12LSZG-280×3000 four-roll plate bending machine,the actual structure is simplified,and the mathematical model of the four-roll rolling process is established,that is,"four rolls one plate".Based on the theoretical analysis of the four-roll rolling process,the finite element model of the plate bending process is established by using ANSYS/LS-DYNA,and the explicit dynamic simulation analysis of the pre-bending and rolling-bending process of the four-roll rolling plate is carried out.The width,thickness,yield strength,pre-bending velocity,feed angle of side roll,upper roll radius,the bottom roll radius,left and right roll radius in the pre-bending process of four-roll rolling plate were studied.The influence of the distance from the intersection of the feed direction line on both sides of the roll to the center of the upper roll on the force and torque of the work roll,and the influence of plate width,pre-bending velocity and roll-bending speed on the phenomenon of staggered edges in the plate bending process during the single-pass roll bending process.The effects of feed,pre-bending speed,roll bending speed,plate thickness,plate width and plate yield strength on the forces acting on the working rolls and the roll forming radius in the roll bending process were studied.The effects of the number of rolling paths and different feed strategies of side rolls on the radius of roll forming in multi-pass roll bending process are studied in this paper.The results show that:(1)in the pre-bending and roll-bending stages,the thickness,width and yield strength of the plate are the most important factors affecting the force acting on the working rolls.(2)in the pre-bending stage,the thickness,width and yield strength of the plate are the most important thing.The size parameters and pre-bending speed of the equipment have little effect on the force acting on the rolls.In the rolling stage,the feed and speed of the side rolls have negligible effect on the forces acting on the rolls.(3)When the thickness of the plate is 90 mm and the width of the plate is 250 mm.the expected radius of neutral layer is 1000 mm and the yield strength of plate is 360 MPa,the feed of side roll cannot exceed 73% of 583 mm,which is the theoretical feed of side roll,the larger the width of the plate is,the smaller the yield strength is when single-pass roll bending is adopted,that is,425 mm.(4)the width of plate is larger,and the yield strength is smaller,when the plate yield strength is 1000 mm.The radius of curvature after bending is larger.(5)the total feed of side roll should be larger than the maximum feed of side roll during single pass roll bending,but less than the theoretical feed of side roll.(6)the less the number of roll bends,the less the feed of side roll should be.At the end of the bending,the curvature radius of the outer layer of the plate is smaller.Based on parametric design language APDL in ANSYS software,parameterized modeling and analysis can be accomplished by changing one or more parameters or groups of parameters which need to be studied in the APDL program.On this basis,the secondarydevelopment of the finite element analysis software of ANSYS/LS-DYNA four-roll plate bending based on Visual Studio is completed.It is convenient for the operation staffs to input the dimension parameters and material property parameters of the equipment at the corresponding interface.After processing parameters and setting parameters related to finite element calculation,the program can be started for calculation and analysis.Through the research of this subject,the reference can be provided for the determination of pre-bending speed,side roll feed and roll bending speed in the actual four-roll rolling process.