Design And Performance Analysis Of Spot Welding Fixture For Thin-Wall Box Parts

Because the thickness of the box panel is thinner,the welding of thin-wall box parts is difficult,and its quality control is also difficult.For the box parts with airtight requirements,it needs to be fully welded and its welding quality is more stringent.Once the sealing performance of the shell of the thin-wall box is not guaranteed,the performance of the various components in the shell will be affected.Especially for the thin-wall box parts with laser full welding,the spot welding of thin-wall box parts is the front process of full welding.The quality of the spot welding determines the quality of the whole welding.Therefore,it is of great value and application prospect to design a matching welding fixture to reduce the welding deformation of the thin-wall box products in the welding process and improve the reliability of the products.This paper is aimed at a certain type of thin-wall box,the principle of welding deformation and the control method of welding deformation are studied on the basis of a large number of documents.According to the structural characteristics of the existing thin-walled box parts,in order to reduce the welding deformation,the distribution of rib reinforcements in the box panel is improved and the statics performance is compared under the working condition.The "(?)" form of left and right panel rib reinforcements distribution is the best in all plans.It not only improves the performance of the box,but also reduces the weight of the box,and saves the processing cost.The spot welding procedure of thin-wall box is analyzed,the placement of the thin-wall box in fixture and welding method are determined.According to the processing requirements,the welding spot's distribution of each soldering seam and the welding sequence of each weld were determined.Control and reduce the deformation of thin-wall box from the welding procedure.Aiming at the processing requirements of the thin-wall box and the design requirements of the welding fixture,the structural design of the welding fixture for the spot welding process of the thin plate box body is carried out.Taking the positioning element for locating the inner surface of the box as the first positioning datum,the fixture body floor is second positioning datum,and the positioning block with the specific installation is third positioning datum.According to the principle of positioning error,the positioning error of each locating element of the spot welding fixture is calculated.The results show that the positioning errors of the spot welding fixture meet the processing requirements within 0.5mm,and can ensure the accuracy of welding process.The static state of the thin-wall box clamped on the fixture is studied,and the deformation and stress of the thin-wall box are discussed.The results show that the deformation of the box panel is between 0.004mm and 0.005mm under the horizontal fast clamper's clamping force of the 300N and the spiral compression device's clamping force from the of 500N,and the maximum stress is 8MPa.The thin-wall box is less affected by clamping force,and the spot welding fixture has certain stability and reliability in the clamping process.The maximum deformation of the front panel in the process of spot welding is 0.22mm,the maximum deformation of the rear panel is 0.14mm,the maximum deformation of the upper and lower panels is 0.18mm and 0.29mm.The maximum deformation of the left and right panels is 0.33mm and 0.23mm.By comparing the welding deformation with the unused welding fixture,the reliability of the designed spot welding fixture is determined to control the welding deformation.In this paper,the rib reinforcements of the thin-wall box is improved.The welding deformation is reduced from the welding procedure.The designed welding fixture meets the requirements of the welding processing.It improves the processing precision and efficiency of the product.It has a certain reference value welding and practical application significance.