Research On Laser Welding Technology Of Commercial Vehicle Compound Brake Camshaft

Increasingly stringent fuel consumption regulations and increasing user perception quality requirements put forward higher and higher requirements for vehicle lightweight work in major domestic and foreign automobile enterprises.Weight loss of automobiles is very important in reducing fuel consumption,enhancing control and power.Of course,automobile lightweight is not simply "reduce the weight of the car",but on the basis of guaranteeing the quality of the car,through the design,material and process of good matching optimization,realize the weight reduction of the car.Hollowing of solid parts is an important means for lightweight design of commercial vehicles.Brake camshaft is one of the important parts in the brake system of commercial vehicles.Traditional brake camshafts are mostly manufactured by forging process and are solid structures.Hollow combined brake camshaft is welded to realize hollow camshaft connection.Compared with the traditional forging solid structure,it has the advantages of reducing the overall weight of parts,reducing costs,realizing flexible manufacturing of multi-series products and optimizing product performance.In this paper,the feasibility of hollow design and manufacture of brake camshaft by laser welding technology is explored,and its application is preliminarily discussed.The main research work includes:(1)In this paper,the laser welding technology of combined hollow brake camshaft is studied.Including: design and welding structure requirements of modular brake camshaft products,laser welding process parameters,design and manufacturing methods of welding fixture,performance testing methods of modular hollow brake camshaft,etc.(2)To compare the effects of single laser welding and high frequency induction-hybrid laser welding on welding quality.Through the comparison of multi-round,multi-angle and multi-direction,it is proved that the high frequency induction-laser hybrid welding method is more effective and can effectively improve the poor weldability of medium carbon steel.(3)To study the factors affecting the welding quality,such as welding materials,structure,power,protective gas,welding methods,equipment and so on.Through multi-round experiments,the reasonable process parameters of high frequency induction-laser hybrid welding of medium carbon steel,especially the selection of protective gas and welding procedure,will have a direct impact on the welding quality.The experiments show that the probability of welding defects can be effectively reduced by choosing low power positioning welding,high power formal welding and He gas protection.(4)The stiffness and torsion strength of the combined brake camshaft were tested,and it was proved that the combined brake camshaft manufactured by high frequency induction-laser welding met the performance requirements.(5)Through the study of process flow and financial accounting,it is shown that the combination brake camshaft structure does not need to adjust the existing production process dramatically,the production and promotion is simple,and has a good application prospect.The combined brake camshaft with laser welding structure can reduce the weight and cost of heavy trucks.