Numerical Control Bending And Simulation Analysis Of Metal Tube

Metal tubes are known as industrial blood vessels in the industrial development;The tube bending process of metal tube has many advantages,such as elastoplasticity,mechanical lightweight,fluid transportation and corrosion resistance,it is widely used in aviation,navigation,railway,light industry and other fields.Meanwhile,it also puts forward higher requirements for the technology,precision and performance of NC bending tubes.The quality and performance of the elbow will directly affect the assembly and structural performance of the industrial pipe fittings.There are many defects in the bending process of pipe fittings,the main problems are bending fracture,flattening,tearing and wrinkling,therefore,it is very important to improve the bending technology of metal tube for the quality of the pipe.Firstly,NC bending technology is the key link to realize the numerical control integration design and manufacture of elbow products,the numerical control simulation programming based on the space geometric coordinate information of the curved pipe is the premise of NC bending.Establishment of coordinate transformation and method description for NC machine tool processing,the mathematical expression of the coordinate transformation of the 3d space control point coordinate to the machine tool is derived,on this basis,the three-dimensional model of the bend pipe is derived,reprogramming software is converted into a processing program.Provide data support for connection between 3d software and CNC machine tools,to solve the transformation of curved pipe space geometry information to machining coordinates.The springback characteristic of tube is very important to the effect of quality of pipe forming,springback is the key link to measure the quality and performance of the pipe,study on the bending principle of bend pipe and the process of deformation forming,The influence of springback and process parameters on the internal and external diameter cracking,inner diameter extrusion,springback and tube wall deformation of tube bending is analyzed,and the influence of machining parameters such as relative wall thickness and relative bending radius on bending quality is verified.The force analysis and calculation formula of bending fittings are deduced,it is concluded that the relative bending radius has great influence on the thickness variation of pipe wall,it is proved that rebound is an important factor affecting the quality of pipe fitting and flattening of cross section.Secondly,in the process of pipe bending,the design and application of mandrel can also play an important role in optimizing the quality of the pipe fittings.It is an important step to improve the quality of elbow pipe.In this paper,the design,structure and principle of the core rod were studied by a manufacturer’s pipe bender(CNC-80 Tube bender).in addition,the diameter of the core rod,the number of protrusion and the number of cores are studied,the influence of core velocity and bending speed on bending quality is analyzed,a reasonable selection and application of mandrel is put forward.The use of mandrel reduces the cost of production,improved quality,it provides theoretical reference and practical guidance for bending tube forming.The last,the calculation and derivation of the springback amount and the technological parameters are obtained,the bending technique of pipe fitting is more reasonable.Through the analysis and design of the metal pipe material,the optimum range of relative bending radius for bending forming is given,simulation analysis and verification are performed.