CVJ Outer Joint Member Welding Crack Prevention

The patent replaces the mechanical friction press-contact joining method with electron beam welding. This substitution eliminates the burr generation problem inherent in friction press-contact while achieving reliable joining of the cup member and shaft member. The electron beam welding process melts and fuses the materials without generating burrs, thus resolving the contradiction between ease of manufacture and burr generation.

The patent applies pre-heating and post-heating temperature parameter changes to control the welding process. By carefully controlling the thermal parameters, the patent achieves complete welding without generating burrs, while also preventing defects like recesses and air bubbles. This parameter control resolves the contradiction by optimizing the welding conditions to eliminate harmful burr generation.

The patent applies pre-heating before welding to raise the temperature of the workpiece. This preliminary thermal action prevents rapid cooling after welding by reducing the temperature differential, thereby avoiding martensite formation and crack generation while still maintaining efficient welding cycle time.

The patent implements post-heating after welding to control the cooling rate. By applying controlled heating after the welding process, the patent prevents rapid cooling that would cause martensite formation, thus eliminating crack susceptibility while maintaining productivity through optimized heating parameters.

The patent optimizes the pre-heating temperature and duration parameters to achieve the minimum necessary heating that prevents crack formation without excessive cycle time extension. By carefully controlling these parameters, the patent balances reliability improvement with productivity maintenance.

The patent combines pre-heating, welding, and post-heating into a continuous thermal process. This continuous action minimizes idle time between operations and ensures that the thermal treatment is applied efficiently throughout the welding cycle, preventing cracks while maintaining overall productivity.

The patent applies pre-heating before high energy intensity beam welding to raise the temperature of the workpiece and hollow cavity portions. This preliminary heating prevents pressure changes during welding that would cause molten material blowing, thereby maintaining welding quality while preserving the high welding speed advantage.

The patent controls the energy intensity and application parameters of the high energy beam welding process to minimize pressure changes in hollow cavity portions. By optimizing these parameters, the patent prevents welding defects like molten material blowing while maintaining high welding speed and productivity.