The Finite Element Analysis Of The Key Parts Of The Four-roll Plate Bending Machine

As a commonly used rolling forming equipment for metal sheet material in container manufacturing enterprises,the four-roll sheet coiling machine has strong universality,easy to operate and convenient to the medium.Therefore,the demand for four-roll coiling machine is increasing gradually,and the demand for its processing precision is also increasing correspondingly.This paper takes the large four-roller coiling machine needed for heavy pressure vessel manufacturing in the enterprise as the research object,determines the structural design method of its key components,and studies the structural composition of the coiling machine,the principle of coil forming,and the technological process.At the same time,in order to ensure the correctness and reliability of the structure of the coiling machine,the process parameters are calculated for the rolling circle and pre-bending conditions in the coiling process,and the strength of the work roll for full loading conditions(pre-bending)is also performed.The stiffness was checked and the Workbench software was used to perform finite element analysis on the strength and stiffness of the high frame,base,and work rolls.First,the bending theory of sheet metal and the deformation characteristics of sheet bending are analyzed.The bending radius,bending moment,curling force and the required driving power of the upper roll are determined as the bending of the sheet before bending.The main parameters of the molding process.Secondly,by analyzing the principle and structure of the symmetrical three-roller coiling machine,the asymmetric three-roller coiling machine and the four-roller coiling machine,the four-roller coiling machine was selected as the ideal bending equipment for heavy pressure vessel manufacturers.The theoretical analysis of the roll forming process of the four-roller coiling machine was performed,and it was clarified that the rolling process includes mainly the steps of centering,pre-bending,rolling,and rounding.The key components of the coiling machine mainly include: Work rolls(upper roll,lower roll and two side rolls),high frame and base,based on which the parameters design scheme of the key components of the four-roller coiling machine was determined.Again,the load on the work roll and the driving power of the upper roll during the rolling and pre-bending conditions are calculated separately.By calculating and comparing the results,the load on each roller during the pre-bending is the largest,and the driving power of the upper roller is the largest when winding,and the input power range of the main motor is determined by this.On this basis,the traditional calculation method was used to check the strength and stiffness of the upper roll,the lower roll and the side roll under the pre-bending conditions.The results showed that the shaft roll structure size set in the design scheme was reasonable.Finally,a three-dimensional model of each structure and its components were established.The finite element analysis was performed on the force conditions of the baseplate,work rolls,and overhead frames of the coiling machine under pre-bending conditions.Analyze,use Workbench software to carry on the model introduction,the division grid,the load to add and the solution to the base,the work roller and the high frame,obtains its stress and the distortion cloud picture.From the analysis results,it can be seen that the deformation of each work roll during pre-bending is very small,and the maximum stress value is far below the yield strength of the material.This result is consistent with the theoretical calculation result,which proves that the roll body material is surplus and the work roll is guaranteed.Simultaneously with the strength and rigidity of the journal,it can be considered to reduce the roller body size of the lower roller and the side roller.Although the maximum stress of the high frame is within the safety range,the stress distribution of the machine body is uneven,and the inner stress value is greater than the outer side.The stress value should be specially treated in the process of designing the parts;at the same time,the weakness of the structure in the pre-bending of the base is pointed out,the structure of the base is improved,in order to increase the strength of the structure,the ribs are added,and after the improvement,The structure was verified,and the maximum stress and deformation were significantly reduced.Through the research of this subject,the design scheme of the key parts of the four-roller coiling machine and the quality control points during its design are given,which provides a way for the more reasonable design of the large-scale equipment composition structure of the coiling machine in the future.Improve the performance and accuracy of equipment structure,and save production costs.