The Research Of Metal Part Forming Control Technology Based On Three-dimensional Welding

The metal part forming technology based on three-dimensional welding is one of the most promising methods to realize the direct manufacturing of high quality and full density metal parts,which combines welding process with rapid prototyping technology and is used in the direct prototyping of metal parts.At present,the accuracy and quality of metal parts manufactured by welding rapid prototyping technology are not high,the main reason is that the thermal input in the molding process is too large and the stability of the molding process is not high.In this paper,according to the characteristics of bypass coupled arc welding process and the principle of rapid prototyping technology,a rapid prototyping method based on single bypass coupled arc welding process is proposed,and its control technology is studied.Firstly,according to the analysis of four methods commonly used in bypass coupled arc welding technology,the welding scheme suitable for three-dimensional welding rapid prototyping technology is worked out in this paper.According to the scheme,the research content of metal part forming control technology based on three-dimensional welding is determined,and the three-dimensional welding rapid prototyping control system of metal part is established according to the research content.The control board selection,communication scheme,three-dimensional motion device and human-computer interaction system of the system are designed preliminarily.Secondly,according to the requirements of three-dimensional welding rapid prototyping control system for metal parts,the software and hardware are designed.The hardware design includes human-computer interaction system hardware design,data acquisition hardware design,bypass wire feeding mechanism hardware design,independent early warning system and welding power interface design.The software design includes the calculation of horizontal weld bead building spacing and vertical weld bead stacking spacing,the calculation of motor speed and rotation angle,and the self-developed control system software.This paper introduces the data format and receiving flow under each communication mode,and formulates the scheme of software anti-interference.Finally,on the basis of theoretical analysis and software and hardware design,the three-dimensional welding rapid prototyping experimental platform of metal parts is built,andthe system experiment and rapid prototyping process experiment are carried out.Through the system experiment,it is ensured that the design content of software and hardware can meet the needs of the control system.Through the rapid prototyping process experiment,the welding torch process parameters suitable for rapid prototyping,the corresponding optimal bypass wire feeding speed range under different main circuit voltages and the stacking molding of horizontal,vertical and three-dimensional weld bead are determined.The experimental results show that the rapid prototyping technology based on single bypass coupled arc welding technology can reduce the thermal input in the molding process,has little effect on the molding accuracy during arc ignition and arc extinguishing,simple equipment and strong controllability.