Why is the automobile gearbox so expensive? Look at the gear technology and you'll see.
As we all know, gearbox is the key component of a car. Its performance directly affects the fuel consumption of the car. The price of high-precision gearbox is very expensive, and the price of imported gearbox has doubled. Why can't our domestic gearbox achieve such effect? This is related to technology stacking. There are many kinds of gear processing technology alone, not to mention more in-depth research. Of course, we will gradually talk about deeper things in the future. Now we will first introduce several gear processing technology.
Note: Spiral bevel gears
1. Hobbing, often used in cylindrical gear processing, straight or helical teeth can be used, this kind of gear is mainly used in the transmission, as a hot pre-processing process, its characteristics are simple debugging, relatively low cost, is now the most widely used process.
2. Milling teeth, which is mainly used in spiral bevel gear processing, is also a kind of hot pre-processing technology. The figure shows the milling teeth on the processing center. This processing method takes a long time. In fact, the main stream is the special helical bevel gear milling machine. The price is very precious. A Grison gear milling machine costs about 5 million yuan, while processing one. There are at least three sets of gears needed to cover such gears, but there is no better way to form such teeth. The efficiency can be improved by improving raw materials and improving the quality of cutting tools.
Note: Milling teeth
3. Grinding is a kind of hot post-processing technology. This kind of gear has higher cost, longer processing time and higher grinding accuracy. It is mainly used in the car gearbox. The grinding gear has smaller transmission errors. It can stick to a lower stir when the car is running at high speed. It improves the NVH of the whole car, but the grinding wheel and the machine tool are compared. The price of an imported first-class cylindrical gear grinder is about 3 million yuan, while the price of spiral bevel gear grinder is over 6 million yuan.
4. Grinding teeth is also a kind of hot post-processing technology. After taking part in grinding agent between two meshing teeth surfaces, two gears roll together to remove the part of the tooth surface which is not ambitious. This technology can directly obtain lower meshing noise, and is more economical and efficient than grinding teeth. However, a domestic grinding machine also costs about 4.5 million yuan. Kou Grison is around 6 million.
Graphic Note: Grinding
5. Gear shaping, which is a lame traditional process, is mainly used to process inner spur ring, but also often used to process products that hobbing can not process. This process is suitable for making double gear and multiple gear. But the disadvantage of this process is that it can not complete dry cutting, and the cost of on-site protection is higher than that of dry cutting milling.
Note: Gear shaping