Design of Welding Positioning Device for Big-Caliber Steel Tube based on TRIZ Theory

TRIZ theory is one of the most practical and efficient methods of innovation in modern times, The article aims to solve the problem of "low efficiency in welding production of Big-caliber steel tube ", based on TRIZ theory, the design of large diameter steel tube auxiliary welding positioning device can be flexible clamping of various sizes of steel tubes, ensure that the big-caliber steel tube fitting can be welded flexibly after being fixed, The practical problem of repeated clamping during welding is solved. 1 APPLICATION OF TRIZ THEORY 1.1 Initial Investigation of Positioning Device Design According to market research, the main function of existing auxiliary welding positioning devices is to completely fix the workpiece, ensure smooth operation of welding, its usage characteristics lead to the tube cannot be rotated or moved after the welder has fixed it, after welding some welds, the rest parts are difficult to be welded, it needs to be fixed and welded again, the working process is timeconsuming and laborious, and easy to appear the sealing-off welding situation, the equipment is not easy for operators to use. Based on the analysis of existing relevant patents, TRIZ theory "SVOP" expression method is used to express the function of the system to be designed, setting design objectives (Countinho J S, 1964): Technology System(S): Auxiliary welding positioning device; Apply Action(V): Fixed/rotated; Action Object(O): Big-caliber steel tube; Parameters of the action object(P): Displacement changes Therefore, the function of the design system is expressed as "auxiliary welding positioning device to fix/rotate the displacement change of big-caliber steel tube". The key problem to be solved in its design is how to save time and effort. Single clamping can complete the whole circle welding with less labor, and put the welding personnel in the best position for easy welding. 1.2 Analysis Design System Problem TRIZ theory has a very systematic analysis method for the problem of innovative design. The main purpose of system analysis is to find the key problems of the whole design system, for the design problems in this article, analysis the function, cause and effect and resources of the design system that can effectively determine the key problems to be solved in the whole system. 1.2.1 System Function Analysis The function of this system is expressed as "the displacement change of big-caliber steel tube fixed/rotated by the auxiliary welding positioning device", according to the system function model figure 1, the negative function of the system is insufficient control of the driving device and clamping device in the human positioning device (Gofuku A, Koide S, Shimada N, 2006). 1.2.2 Systematic Causal Analysis 5Whys analysis method is adopted to carry out causal analysis on the design system, In the fivequestion analysis method (figure 2), Let's start with Ji, L., Sun, X., Zhang, N. and Wan, M. Design of Welding Positioning Device for Big-Caliber Steel Tube based on TRIZ Theory. DOI: 10.5220/0008848901650171 In Proceedings of 5th International Conference on Vehicle, Mechanical and Electrical Engineering (ICVMEE 2019), pages 165-171 ISBN: 978-989-758-412-1 Copyright c © 2020 by SCITEPRESS – Science and Technology Publications, Lda. All rights reserved 165 the question "why is the efficiency of big-caliber steel tube (round) not high in the welding process?”, Figure 1. Function model diagram of auxiliary welding positioning device. Fig 2. 5Whys method diagram of auxiliary welding positioning device. explore the cause of the problem through two lines of questions, derive the ultimate cause of the problem finally "Steel tube welding positioning device is fixed", it follows that, We believe that the design of the welding positioning device of steel tube into an overall adjustable type may become a research focus of this product. 1.2.3 System Resource Analysis ICVMEE 2019 5th International Conference on Vehicle, Mechanical and Electrical Engineering