How many years is the level of domestic AT transmission worse than that of foreign countries?

How many years is the domestic AT transmission worse than foreign countries?

There are many reasons why China can't make a good transmission at present.

Among them, there are both external technology blockade factors and the fundamental reason why high-tech steel processing technology is relatively backward.

Technical Barriers and Patent Blockade

Speaking of technical blockade, there is an article "Domestic Transmission: A Long Way to Go" in Automotive Times magazine, which mentions that China has been independently researching and developing automotive automatic transmissions for more than 20 years.

After 7 or 80 years of development abroad, the technology has matured and is 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, which mentioned the research on hot issues of automatic transmission parking gear at home and abroad based on patent application.

An example of applying automatic transmission parking technology is given.

Toyota, Honda, Aisin and other foreign car companies have applied for patents on the methods related to the detection and control of electronic systems in view of the possible problems in using parking gears in real life, and basically registered them.

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 infrastructure design of automatic transmission or parking gear.

We need to make more efforts and take more detours.

It's like saying: I want to eat a stewed chicken today, but I found that this has been patented, so it won't work. what can I do? It took a lot of effort, didn't it?

I made a vegetarian chicken with dried tofu. I have to imitate the taste of chicken, and I have to debug it again and again. Finally, I have to stew it, but I am more tired 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, domestic car companies have 1 patents related to control modes, but now there are so few patents, only 1 patents.

Material cause

There is actually another reason: raw materials.

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 to solve it.

The above-mentioned Harbin Institute of Technology paper "Preparation and Microstructure and Properties Analysis of Gear Carburized Steel 18CrNiMo7-6".

The production and research of gear steel in China are relatively late. At present, our mature gear steel material is 20CrMnTi.

Compared with foreign gear carburizing steel, this steel contains a lot of hard tin particles with obvious edges and corners, which is easy to cause fatigue cracks and brittle fractures and has a relatively short service life.

Just like a piece of jade, if there are many impurities in it, then the quality of jade is relatively low.

In addition, the variety of gear steel materials produced in China is chaotic and unsystematic, and the qualification rate and application scope are not as good as those of foreign countries. In raw material production, there is indeed a gap with developed countries.

Overall matching reason

Furthermore, developing automatic transmission is different from developing manual transmission, right?

Automatic transmission, its development is more closely related to the whole vehicle. Harbin Institute of Technology's thesis "Research on Control Method and Development of Simulation System for Automobile Automatic Transmission" has been mentioned.

Automotive electronics integration has become a trend, including what?

Electronic ignition system, electronic fuel injection system, electronic automatic transmission, automobile cruise control, electronic brake anti-lock system, electronic suspension and so on.

It is no longer a relatively independent system. I lack this thing, study this thing. Now all the collections are integrated.

This involves a matching problem, which requires a lot of experimental data to do well.

Take several shift parameters mentioned in the article as an example: the shift time has a great relationship with the shift quality. The longer the time, the better the quality, but the greater the wear of friction elements.

Just like walking: the slower you walk, the quieter your steps will be, but at the same time, you will walk slower and slower before landing, 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 and can only be calibrated by trial and error.

The same is true for other data, such as clutch pressure, which requires a lot of tests.

For domestic car companies that started the transmission research relatively late, it takes time and there is no way.

A pregnant woman needs 10 months to give birth. We should speed up and work hard. Even if there are 10000 pregnant women, it still takes 10 months, right?

There is still a gap between domestic production level and foreign countries.

So generally speaking, there is still a certain gap between domestic transmission production level and foreign enterprises, but domestic car companies are really catching up.

While studying the traditional AT gearbox, on the other hand, it has begun to make achievements in the field of dual clutch or other automatic gearboxes.