First,? Ordinary gearbox
According to the different working principles and modes of automobile shifting, there are four kinds of automatic gearboxes commonly used in automobiles (especially fuel vehicles), namely hydraulic automatic gearboxes, mechanical stepless automatic gearboxes, electronically controlled mechanical automatic gearboxes and dual-clutch automatic gearboxes. Of course, there are MT gearbox, manual gearbox and gearbox designed with the earliest industrial application and the most basic gearbox principle. At present, it is still used in some low-equipped vehicles or special vehicles (off-road vehicles, engineering vehicles, etc.). ). I won't go into details here. Today, I only talk about the automatic gearbox.
So far, the gearbox of fuel vehicles has been basically taken over by several large companies. In addition to Aisin, ZF is also a relatively advanced gearbox brand. Borgwarner and Gateke each have their own technical advantages, and they are both good at making achievements in their own transmission technology fields.
1, AT gearbox (automatic? Transmission? , abbreviation? AT), the scientific name of hydraulic automatic gearbox, should be the most used and contacted automatic gearbox at present. From the early contact with 4AT gearbox to the present, some cars are equipped with 9AT gearbox, and there are quite mature models at all levels. The advantages of AT gearbox are obvious, the power is "more direct" and the disadvantages are also prominent. The first and second generation products may have a sense of frustration when accelerating, and the shortcomings of relatively high fuel consumption. However, due to its mature structure, large usage and relatively low cost, the brands used are also the most extensive. In addition to Toyota models, other German, European and American departments and most domestic departments are also in use. Of course, now it is the third generation product, and its relative stability and fuel consumption performance have improved a lot.
2.CVT gearbox (continuous? Variable? Transmission (CVT), whose scientific name is mechanical stepless automatic gearbox, is mainly represented by Japanese cars. Most models such as Honda and Nissan use CVT gearboxes. The characteristics of CVT gearbox are obvious. Because the steel belt or chain realizes speed change by changing the diameters of driving wheel and driven wheel, the speed change ratio is not a discontinuous point, but a series of continuous values. Therefore, it not only has good ride comfort, but also has excellent fuel economy control. Of course, there are also shortcomings, such as the inability to withstand excessive torque output, relatively inferior instantaneous output explosive force, and relatively dull driving experience. Of course, CVT gearboxes are also developing. By increasing the planetary gears, the transmission ratio and torque output are increased, and the internal working conditions of the hydraulic torque converter are changed. Now it can bear about 500NM of torque. For example, Nissan Teana's 2.0T is a large torque CVT gearbox. At the same time, the reliability level of steel belt or chain drive has been greatly improved compared with earlier models. In the current situation of global energy conservation and emission reduction, CVT is efficient, smooth and energy-saving, which makes more and more brands begin to adopt it. Let's talk about the main manufacturers and brands of CVT.
3.AMT gearbox (automatic? Manual? Transmission (AMT), the abbreviation of electronically controlled mechanical automatic gearbox, is a compromise product of MT gearbox and AT gearbox. Compared with manual gearbox, AMT gearbox has the advantages of lower production cost and more convenient operation. However, the disadvantages of AMT gearbox are more prominent, and it is easy to have a strong sense of frustration if it is not operated well, which greatly affects the comfort, and there are fewer models equipped with AMT gearbox on the market now.
4.DCT gearbox (dual clutch? Transmission (DCT), short for dual clutch automatic transmission. Double clutch, as the name implies, adopts two groups of clutches, which work alternately to achieve the effect of shifting gears without clearance. It can be divided into dry double clutch and wet double clutch, with powershift, fast shifting speed, small power loss during shifting and good fuel economy. However, the dual clutch gearbox technology has high realization conditions, high requirements for materials and technology, and obvious shortcomings. The stability of quality and high price are the disadvantages of dual clutch.
Limited by space, today we will talk about Aisin's automatic gearbox separately.
Second,? Ai Xin's background:
At present, Aisin is obviously a gearbox with wide application and coverage. Of course, Aisin is not a monopoly. In addition to Toyota, Nissan and Honda, the other two Japanese bosses also have their own gearbox supporting companies.
Japan Aisin Seiki Co., Ltd. (Aisin? Seiki), referred to as Aisin for short, 1962 was established in Japan, and is an enterprise specializing in the production of automatic transmission and other automobile products. Toyota Group owns 22.2% of Aisin Seiki. Of course, the second and third largest shareholder is Toyota, so Aisin is Toyota's statement, no problem.
Aisin's automatic transmission product line is very rich, with 4 gears, 5 gears, 6 gears and 8 gears. Because it is Toyota's own holding company, almost all Toyota models use Aisin's automatic gearbox. Of course, taking ZF as an example, it is also a major automatic gearbox brand, and ZF will be more adopted by German and European departments. Jacto, mainly CVT gearbox, is mainly used in other Japanese (mainly Nissan, Mitsubishi, etc. In addition to Toyota Honda, there are also a few automatic gearboxes, such as Jacto? 7AT (adopted by Toule, Infineon, Mercedes-Benz and other models).
After 30 years of rapid development, especially in the recent 10 year, China auto parts industry has entered a new stage of "deep localization", from simple vehicle assembly and localization of internal and external basic parts to joint venture mode of core parts, until today's high-barrier core parts (engine gearbox, etc. ) are deeply localized. However, in the field of automatic transmission, this trend is not clear. The foreign automatic transmission represented by Aisin 6AT still occupies the main force of the market, and of course it also occupies the inner recognition of consumers.
It must be affirmed that Aisin, especially the 6AT gearbox, has a development history of more than 20 years and has the cost advantages of mature technology, stable quality and mass production. It is not a helpless move for domestic and foreign or joint venture automakers to adopt such gearboxes. More understanding is that they are responsible for the quality of vehicles and consumers.
However, joint ventures or domestic automakers are more worried because they can save R&D costs. The core technology of automatic transmission is monopolized by giants such as Aisin, ZF, Borgwarner and Gateco. It is too difficult to break down professional barriers, and the patent cost is very high. In addition, it is obviously not cost-effective for fuel vehicles. And even if the investment is huge, you may not get an excellent automatic gearbox. Even if you really make an excellent gearbox, it may not be recognized by the market and consumers. This is the biggest problem. What's more, this kind of gambling development is huge and unacceptable for manufacturing industry.
If the whole vehicle enterprise directly purchases Aisin 6AT gearbox, it can not only ensure the quality, but also improve the profit and sales. As long as a self-owned brand car is labeled as Aisin, consumers will give unlimited trust to its gearbox, which virtually saves tens of millions of advertising expenses. Why not?
From this, we all agree that Aisin, with sufficient technology accumulation, controllable cost and excellent production capacity, is of course the best choice. For Aisin, getting out of this "passive" monopoly position is also a pleasure. Therefore, most domestic brands have adopted Aisin, which is the reason.
Third,? Why is Aisin 6AT the most popular?
Aisin 6AT adopted two sets of planetary gears from the beginning, which has the advantages of reducing the fuel consumption during upshifting and expanding the locking range, which is very helpful for reducing fuel consumption. At the same time, the energy-saving valve is a brand-new and efficient design, which can make better and more reasonable use of fuel when starting or stopping, and the electronically controlled pump also improves the fuel efficiency by 9%.
The other is the technical design of mute. A long-stroke shock absorber is added to the torque converter, which effectively suppresses the shift vibration. In addition, the gear teeth are wider, which is also conducive to the engine to maintain a relatively low speed, which not only reduces the low-speed fuel consumption, but also makes the noise relatively small. There is also a new technology: TCM control unit, which has the quick shift technology of gearbox control computer intelligent program, greatly improving the quiet and smooth ability.
These two advantages exist, so Aisin 6AT has a wide range of market applications, which leads to the phenomenon that the production capacity of domestic brands is controlled and the core components can only be purchased. Although Changan has developed 6AT gearbox before, as mentioned above, because the technology and technology can't meet the design requirements, of course, the products can't meet the current loading requirements. Therefore, the third generation of Aisin 6AT is still the mainstream of the market, firmly controlling the domestic auto market.
In addition to the above innate advantages, as the main product of Aisin, the wide adoption of 6AT is not accidental.
Up to now, Aisin 6AT has reached the third generation. After three generations of evolution, this 6AT has become more mature and stable.
Generally speaking, the technical points of the later generation are as follows:
Compared with the first generation, the locking clutch of the second generation is replaced by a long-stroke spring, and the locking area is increased. This means wider transmission ratio and low torque lift.
Compared with the second generation, the third generation is lighter, with lower speed ratio and built-in electromagnetic oil pump supporting start-stop function.
Lightweight is the most technical upgrade, and the reduction of speed ratio greatly improves the shift smoothness. Of course, the general configuration of automatic start-stop now has new requirements for this 6AT, and the electromagnetic oil pump is used to automatically downshift to realize the start-stop function.
Therefore, we can see that the "love" of domestic brands for Aisin is the most rational and helpless choice, not to mention a German, European or American joint venture. Aisin will exist as "God" in China market for a long time.
This article comes from car home, the author of the car manufacturer, and does not represent car home's position.