| In the manufacture process of steel mesh reinforcement used in the mines, the production of steel mesh was implemented completely by hand operated electric-arc welding, which brings great labor intensive, severe environment and controls quality difficultly. Aimed at the development of a series of factory produced steel mesh for mines, the paper focused on the control system design of big grid and non-equant automatic welding equipment, and investigated the program which realized constant current control by adopting high performance programmable logic controller (PLC) and integrated chip trigger controlled welding power source.The traditional design used PLC as mechanical control system and single chip controlled welding power source as segregated control system. In consideration of the complex software design, high cost and unreliable industry application of single chip while high reliability of PLC as a control device specialized design for industry, this paper combined PLC and high performance trigger and devised a high efficiency welding control system with high integration and simple program. The welding control adopted trigger synchronous voltage. Collection circuit collected the current of secondary circuit, high speed interrupt program in PLC worked out effective current value, D/A module output control trigger outputted trigger pulse and triggered silicon controlled rectifier (SCR), and then the weld was realized.The system takes advantage of the characteristics above two kinds of control devices. In order to make mechanical control and welding control to achieve high efficient operation, the design proposals of modularity and systematization were used. The mechanical control mainly designed rebar automatic sorting function, which realized the function of exact sorting in sequence of non-equant rebars. The functions of pulse, reset and alarm were also designed. Moreover, the system operation schedule about weld failure due to voltage was considered.
|
PDF Full Text Request