SHINHOP laser

There are many types of workpieces that need welding in automotive parts, others include automotive seats, transmission gears, angle adjusters, etc., all of which require welding production. We will analyze the advantages of laser welding technology using automotive transmission gear laser welding as an example, as well as the welding techniques that different gear types need to adapt to during welding. Currently, the types of automotive gears include spur cylindrical gears, helical cylindrical gears, bevel gears, and quasi-hyperbolic gears, which are widely used in automotive transmissions, synchronizers, transfer cases, and drive axles.

Automobile transmission gear laser welding has developed only in recent years, emerging with the advancement of laser welding technology. It has already gained attention in the automotive manufacturing industry and has become an important equipment for future welding processing. Traditional machine tool processing technology has limitations, often using resistance welding, induction welding, ultrasonic welding, or electron beam welding. Due to the structural shape, size, and complexity of automotive parts, it is impossible to perform overall processing and single-piece welding, resulting in low welding processing efficiency and poor precision, which reduces the safety factor of automobiles. To solve these existing welding processing problems, new laser welding technology is adopted, effectively addressing the aforementioned welding shortcomings!
Automobile transmission gear laser welding has the following advantages:
1. Laser welding of gears does not need to be performed in a vacuum, and it can avoid welding deformation, ensuring that the welded gears do not require further machining.
2. Laser welding can achieve a weld depth-to-width ratio of up to 10:1, and the weld has mechanical properties that are comparable to or superior to the base material, ensuring that the gears can transmit a large torque.
Laser welding of gears has become a major trend in today's development. To improve the safety quality factor of automobiles, major automotive manufacturers around the world are competing to adopt laser welding for composite transmission gears to enhance product competitiveness in the international market. The number of manufacturers in China adopting laser welding for automotive gears is also increasing, such as Shanghai Volkswagen, Shanghai General Motors, and Shanghai Chongqing Gearbox Factory.
The process sequence for laser welding transmission gears is as follows:
1. Welding Cleaning: Generally arranged as the first process before welding. In experiments, anhydrous ethanol is chosen to replace industrial cleaners for cleaning the surface before welding.
2. Press-fitting: The cleaned gears must first undergo press-fitting, which is the process of tightly joining the two parts to be welded together using a press. The offset of the incident laser spot and the assembly gap requires very precise alignment.
Because the laser beam's focused spot is very small, the weld needs high precision positioning. The maximum allowable deviation of its position is determined by the radius of the focused spot, generally not exceeding 0.1 mm; otherwise, welding failure may occur. If the height difference between the two mating surfaces is too large, it will cause a significant amount of laser beam energy to be reflected away, affecting the depth and uniformity of the weld. Therefore, after press-fitting, the flatness difference is generally required to be less than 0.1 mm.
3. Preheating (optional): To avoid welding cracks, preheating may be required before welding depending on the material and processing state of the parts, especially for parts with high carbon content or those that have undergone heat treatment and carburizing.
4. Laser Welding: Using an IPG 6000 fiber laser to weld the transmission gears, taking the 20MnCrS5 double gear of the second gear after isothermal normalization as an example. The welding process adopts a pre-weld circle + deep fusion weld circle, with Figure 1 showing the photo of the welded gear. The cross-section of the weld is shown in Figure 2.

5. Post-weld Inspection: Generally, the weld is cut open for microscopic observation or ultrasonic testing. Visual inspection requires minimal welding spatter, little spatter on the working surface, and fewer internal pores and shrinkage cavities.
There are many types of lasers, each with different advantages based on their generated laser wavelengths and characteristics. Currently, fiber lasers are the main light source and are widely used in laser welding applications. Ten years ago, China's laser manufacturing technology level still had a certain gap compared to foreign countries, and many automotive transmission gear weldings required imported foreign laser welding machines. However, in the past decade, through technology introduction and innovation, China's laser technology has developed rapidly. Currently, the technology for laser welding machines for automotive transmission gears not only achieves domestic self-sufficiency but also realizes partial equipment exports. This represents a breakthrough manufacturing technology in the welding of automotive cylindrical gears, helical cylindrical gears, bevel gears, and quasi-hyperbolic gears.

Currently, SHINHOP laser welding equipment in automotive transmission gear welding technology is becoming increasingly mature. The system equipment can control weld porosity and cracks, meeting the requirements for industrial production and ensuring the safety quality level of automotive manufacturing. Moreover, the welding method is reliable and efficient. However, for users, purchasing such high-end transmission gear laser welding machines may require a larger initial investment. Still, from a long-term application and production efficiency perspective, it significantly improves production efficiency, reduces production costs, and enhances the technical quality level of products, thereby increasing the market competitiveness of products. The adoption of laser welding for transmission gears will also become a major trend in the future development of the automotive industry, and it is still developing rapidly. If you miss this fast-developing window, the competitiveness of your product in the market will be greatly discounted.