Development Of Key Equipment For Automatic Welding Of Screws For Composite Heat Sources

According the need of high quality and efficient welding automation between high strength and thickness steel and large diameter stud, after the studies on the arc stud welding technology about cut deal join with large diameter stud and the robot control technology, proposed a solution for automatic hybrid welding stud, designed an induction + arc composite heat source welding studs workstation system, the workstation is mainly composed of a composite heat source welding head, six axis industrial robot, arc stud welding power, pre-heating induction power, stud feeding machine and holding machine, feed and gas system, the total control system and so on. The robot workstation can solve the following problems, poor welding quality, low efficiency and inaccurate positioning.The design for welding head modular main contains the fixing of arc stud welding gun, the clip for different diameter stud, the clamp of induction heating head and the servo motor for driving it rise and fall, its positive rotation and reverse rotation judge on the preheat requirement. Choose aluminum alloy materials as far as possible for the fixture design, reduce the material types to the minimum.After completing the structure design, use SolidWorks Simulation environment for the conduct of the force and deformation simulation, arrival at a conclusion that the head structure meet the stiffness and apply requirement. Using gas claw clamping the stud, the gas claw’s open and close is under the control of Electromagnetic reversing valve. At last, connect all of the above modular to the independent research and development control center, which is the communication interchange between robot control cabinet and all welding modules.From the outside to buy the welding positioner, and then independent design the support tray and fixture, carries on the analysis of deformation load using Static Structure module of ANSYS WorkBench, the load’s obtained method is to use SolidWorks drawing a 1:1 3-D model, defining material properties, and then show the weight by software. Finally draw a conclusion that the welding positioner’s maximum deformation is more than 4mm under the maximum load, which is far beyond the requirements. Different welding pose should re calibration to offset positioner’s deformation.The design for stud feed mechanism should meet the different diameters stud’s feed requirement and the feed continuity. In this paper, after studied the shape of the studs and the ceramic rings, Redesigned the studs with a shaft shoulder, which can hold the ceramic rings; Redesigned the stud feeding disc with permanent magnet, which avoid dump when the stud plunge and get away from the limit of stud’s diameter; Choose ratchet structure for controlling the rhythm of stud feed, cylinder as the implementation of components for feeding, which is easy to the communication with the system control center. The control center is integrated into the robot control cabinet, which make the layout more reasonable and more practical.After debugging and testing, the equipment is in good working order. Based on the mature manual arc stud welding process parameters conduct automatic stud welding, then obtain the process parameters for robot automatic welding. At last make sure the solution can greatly improve the stud welding production efficiency, results quality of product is stable and craft is reliable, has the ability to apply to large-scale industrial production.Therefore,the main achievement in this thesis include the following results: redesigned all of the modules based on the original robot workstation, make the equipment more convenient and stable, provides a full set of solutions for composite heat source stud welding automation, such as stud’s feeding and clamping are less encumbered with its diameter and length, the introduction of permanent magnet avoid dumping during feeding; the follow control lines design concepts make the mechanical arm movement more flexibility; the introduction of welding positioner makes all solder joints are flat, which is help to improve the welding quality. In addition, normative requirements also be provided for later maintenance and re-manufacturing, so that the normal operation of the equipment is not only limited in the laboratory.