Arc Influencing Factors Analysis And Welding Torch Control Strategy Research Of Vacuum Brazing

Vacuum arc brazing technology is a new and unique brazing technology, it has great potential applications in the aviation industry. Vacuum arc brazing equipment is the main equipment of China aviation enterprises for blade of aviation engine repair work. However, there are two problems with vacuum arc brazing technology, creating arc is difficult and the welding torch can not automatically adjust arc length. In order to solve the problems, this article consults and researches a lot of the existing theory and data, combines the project——Reform of the vacuum brazing equipment electrical system, of the my tutor, and uses the method of field investigation, theoretical research, numerical simulation and experimental research, studies the influencing factors of the arc and welding torch control strategy of the vacuum arc brazing. The main research contents include:(1) This article analyzes the composition and working principle of vacuum arc brazing equipment, establishes the three-dimensional model and kinematics model of the welding torch welding manipulator. This article analyzes the structure and kinematics of welding torch, puts forward the requirements of welding torch control system. At the same time, by using the ADAMS software, the article does the research of kinematics simulation, gets the motion characteristics of the lifting mechanism; it proves that the lifting mechanism can meet the requirements of the process of vacuum arc brazing.(2) Based on the basic mechanism of arc established, this article analyzes the effect of various factors in the process of the arc, studies the effect of each factor on the arc is established. The mathematical relation between the influence factors and the arc is established, and gets the trend of effect of various factors on the arc established; And according to the requirement of vacuum arc brazing process of the reality, gets the value or range of values of the influence factors, when they are the most conducive to the establishment of the arc.(3) This article analyzes the static characteristics of arc, establishes the mathematical model of the relationship between the length of arc and arc voltage, and uses the method of parameter identification with experimental data, solves the mathematical model by using MATLAB software. A fuzzy-PID control system of welding torch is established, and this article does simulation of the control system, proves that the control system has good response and stable characteristics.(4) By using the vacuum arc brazing equipment which has been reformed, this article do the experiment analysis of the influencing factors in the arc by using the method of variable substitution, verifies the theoretical results, and gets the value of the influence factors, when they are the most conducive to the establishment of the arc. This article also does the experimental study of welding torch control system, the experimental results show that the fuzzy-PID control system can be very good for the arc length control, has a good control performance, verifies and improves the theoretical research achievements.