How many years is the level of domestic AT transmission worse than that of foreign ones?
AT present, there are many reasons why a good at transmission can't be made in China.
there are both external technical blockade factors and fundamental reasons that the high-tech steel processing technology is relatively backward.
Technical Barriers and Patent Blockade
When it comes to technical blocking, there is an article in auto time, "Domestic Transmission: A Long Way to Go", which mentions that the history of China's independent research and development of automobile automatic transmission is more than 2 years.
foreign countries have developed for 7 or 8 years, and the technology is mature, and they are firmly in the hands of major vehicle companies and transmission suppliers.
these foreign car companies and gearbox suppliers basically have strict technical blockade on domestic enterprises.
there is a paper in the journal of mechanical and electrical engineering technology, and the research on hot issues of automatic transmission parking gear at home and abroad based on patent application is mentioned above.
An example is given by using automatic transmission parking technology.
Toyota, Honda, Aisin and other foreign car companies have patented the methods related to the detection and control of electronic systems in view of the problems that may be encountered when using parking gears in real life, and basically registered them all over.
well, if our domestic car companies want to solve the same problem, they can only bypass these patents and solve this problem by improving the basic structural design of automatic transmission or parking gear.
it will take more effort and detour.
it's like saying: I want to eat a stewed chicken today, but it turns out that this one has been registered as a patent, so it won't work. What can I do? It took a lot of trouble, didn't it
I use dried tofu to make a vegetarian chicken to imitate the taste of the chicken, and I have to debug it repeatedly, and finally I have to stew it, but it's even more tiring than others, right?
The number of patents can also clearly reflect this problem.
compared with dozens of patents of foreign car companies on this issue, there is only one patent related to control methods in domestic car companies, which is so small just now.
Material reasons
Actually, there is another reason: raw materials.
for example, take steel as an example: although our country is already one of the largest steel producers in the world, there are some key steel products with high technology content and high added value.
For example, gear steel, which is indispensable for AT transmission, is still difficult to produce in China, and basically needs to be imported.
Harbin Institute of Technology's paper, "Preparation and Microstructure and Properties Analysis of Gear Carburized Steel 18CrNiMo7-6" mentioned above.
the production and research of gear steel in China are relatively late. At present, our mature gear steel material is still 2CrMnTi.
compared with foreign kinds of gear carburizing steel, this kind of steel has a large number of hard TiN particles with obvious edges and corners, which is easy to cause fatigue cracks and brittle fracture, and its service life is relatively short.
just like a piece of jade, if there are more impurities in it, the quality of the jade is relatively low.
in addition, the varieties of gear steel produced in China are disordered and unsystematic, and its qualification rate and application scope are not as good as those of foreign countries. In terms of raw material production, there is indeed a visible gap with developed countries.
overall matching reason
secondly, developing an automatic transmission is different from developing a manual transmission, right?
automatic transmission, its development is more closely related to the whole vehicle. Harbin Institute of Technology's paper, "Research on Control Method of Automobile Automatic Transmission and Development of Simulation System" has talked about it.
the integration of automobile electronics has become a trend, what does it include?
electronic ignition system, electronically controlled fuel injection system, electronically controlled automatic transmission, automobile cruise control, electronically controlled anti-lock braking system, electronically controlled suspension, etc.
It is not a relatively independent system. I lack this thing and study this thing. Now all the sets are integrated.
this involves a matching problem, and it takes a lot of experimental data to do it well.
Take several shift parameters mentioned in the paper just now as an example: the shift time has a great relationship with the shift quality. The longer the shift time, the better the quality, but the greater the wear of friction elements.
It's like walking: the slower you walk, the quieter your footsteps will be, but at the same time, you will walk slower and slower before landing on your legs for a long time, and you will be very tired, right?
and it's not over yet. The shift duration will be adjusted on the basis of the throttle opening, which can only be calibrated by trial and error.
other data, such as clutch pressure, are the same, that is, a large number of tests are needed.
For the domestic automobile companies that started the transmission research relatively late, it takes time and there is no way.
There is a pregnant woman who needs 1 months to give birth. We should speed up and work hard. Even if there are 1, pregnant women, they still need 1 months, right?
There is still a gap between the domestic production level and that of foreign countries
So generally speaking, there is still a gap between the domestic transmission production level and that of foreign companies, but domestic car companies are really catching up.
while studying the traditional AT gearbox, on the other hand, it has also begun to make achievements in the field of dual clutch or other automatic gearboxes.