Research On Sheet-thickness-adaptable Roll Forming Technology

Roll forming is an efficient,energy-saving and environment-friendly sheet metal forming process.In roll forming production,the roll gap size needs to be adjusted frequently to meet the forming requirements of sheets with different thickness.The traditional manual adjustment method has low efficiency and big error.Therefore,optimizing the roll gap adjustment method to improve production efficiency has become a research hotspot in the field of roll forming.In this thesis,the sheet-thickness-adaptive roll forming technology is studied by combining structural design,finite element simulation optimization and experimental verification.The main work and conclusions are as follows :(1)The structure of the electromagnetic sheet-thickness-adaptive roll forming auxiliary device is proposed.In essence,it is a stiffness-adjustable device formed by parallel connection of electromagnetic spring and disc spring.The auxiliary device is installed between the adjustment screw and the upper bearing box of the traditional roll forming equipment.It can quickly adjust its stiffness to meet the working requirements by switching current while ensuring strong bearing capacity.It can not only realize the stepless adaptation of roll gap but also realize the stepless adaptation of forming force,and finally achieve the technical goal of sheet thickness adaptive roll forming.(2)ANSYS-Maxwell and ANSYS-Workbench are used to jointly simulate and optimize the adaptive device.The control variable method is used to determine the optimal dimensions of 11 key parts such as pitch,tooth height and tooth width of the electromagnetic spring,and the selection of the disc spring part is completed.The performance test of the adaptive device prototype has been carried out.The test results show that under 16 test currents between 1.2 A and 2.7 A,the biggest difference between the experimental force peak and the simulated force peak of the adaptive device in the compression displacement of 0 mm-2 mm is only 43.40 N.The extreme point of the actual force curve is shifted from the preset 2.0 mm of the simulation to 1.6 mm,but the offset phenomenon does not affect the realization of the adaptive forming technology of the sheet thickness.The performance test results of the adaptive device are satisfactory and can meet the design expectations.(3)The prototype of the adaptive device is installed on the roll forming equipment for experimental verification.The traditional adjustment mode is used as the control group to evaluate the self-adaptive adjustment effect of the adaptive device.The roll forming experiments of six types of thickness sheets in three passes under adaptive adjustment mode were carried out in turn,and the forming force and profile angle of various thickness sheets in the forming process were calculated.The experimental results show that the biggest error between the forming force in the adaptive adjustment mode and the forming force in the traditional adjustment mode is8.73%,and the maximum error of the profile angle in the two adjustment modes is4.17%,which meets the requirements of use.It proved that the adaptive device can greatly improve the roll gap adjustment efficiency while ensuring the satisfactory forming quality of the metal sheet,and realize the technical goal of adaptive roll forming of sheet thickness.