Design For Integrated Fixture Of Laser Cutting And Welding And Research On The Effects Of Align Deviation Value On The Performance Of Weld Seam

The automotive industry has been called “the industry of industries” among theindustrial powers. With the increasingly intense competition in automotive industry,high-efficiency and high-quality manufacturing technology applications will becomethe tendency of automotive industry development. Laser welding technology has beenplaying a increasingly extensive role in the automotive body manufacture due to itsprecision, low distortion, high production rate, efficacy with difficult-to-weldmaterials and process flexibility capabilities. Compared with traditional weldingmethods, laser welding technology can be used to reduce the weight of auto body andbody material consumption, lower the cost, and ensure the safety performance of thebody through improving assembly precision and rigidity of the body. Thus, thistechnology gradually becomes a standard welding process in the automotive bodymanufacture. The automotive industry is very important to China’s economy，butthere are still significant gaps between China and any other industrial powers in theautomotive core technology and the ability of independent innovation. The study ofbasic theory and technology of laser welding and other advanced technology will helpto break down the foreign monopoly and enhance China’s integrated capacity ofmanufacturing equipment and promoting development of national auto industry.Reviewing the current research home and abroad, this paper proposes a newmethod-integrated fixture of laser cutting and welding of three-dimensional drawingparts, based on the welding path simulation of robot. Through repeated trialproduction, the effects of the align deviation value and the butt joint gap toautomotive galvanized steel of fiber laser welding are intensive studied.Firstly, the welding path simulation of robot has been researched and analyzed indetail. After introducing the structural characteristics of the robot, the vehicle frameand its fixture are selected. DELMIA is adopted to realize the simulation of weldingprocess, optimal control of movements, ensure the welding process run smoothly andprovide the basis for designing and trial-producing the fixture.Secondly, the characteristics of laser cutting and laser welding fixture have beenanalyzed. A new method of integrated fixture of laser cutting and welding ofthree-dimensional drawing parts is invented. It can correct the resilience of stampingparts, avoid the distortion caused by welding thermal stress, ensure the high process accuracy and quality, and realize the laser cutting and butt joint of three-dimensionaldrawing parts. The integrated fixture of the front longitudinal beam is designed andtrial-produced to ensure the high accuracy and quality butt joint of the frontlongitudinal beam. The weldments is satisfactory for engineering design because ofits energy absorption effect.Finally, the effects of the align deviation value to automotive galvanized steel offiber laser welding are studied intensively. The orthogonal test is adopted to obtainthe best ideal parameters without align deviation. Weld topography and cross sectionof different align deviation value are analyzed, micro-hardness、mechanical propertiesand micro-structure of weld are tested, and the effects of different butt joint gaps onthe critical align deviation value are analyzed. The results show that when the aligndeviation value is less or equal to0.30mm (about17%of sheet thickness), the weldtopography is even and continuous, the micro-hardness in the fusion zone and heataffected zone is higher than that in the base material, the tensile strength of fusionzone is better than that of the base material, the change of the align deviation valuedoes not have much impact on the micro-structure of weld, and the butt joint gap has abig influence on the critical align deviation value.