Alison took out a document and put it in front of Ling Shizhe, it seemed that he had made full preparations this time.

There are two ways to classify gearboxes, one is according to the transmission ratio: continuously variable transmission, continuously variable transmission and integrated transmission. Among them, the variable transmission is the most widely used, and the bridge truck and light and medium-sized trucks are all used in the variable transmission; CVTs are used in trams and heavy-duty trucks, as well as in super-heavy-duty dump trucks. The automatic transmission is a comprehensive transmission, which is used in the field of axle vehicles.

At present, the main use in the European and American passenger car markets is AMT (sequential transmission), a semi-automatic transmission that is modified from the original mechanical transmission (manual transmission).

In 1972, the German company Bosch developed a 4AT (hydraulic automatic transmission) that uses a planetary gear mechanism for transmission, which is expensive and is currently only used in high-end cars in Europe.

At present, it is common for luxury passenger cars in the Americas to use the Tiptonic (automatic manual transmission). As for the TCD (dual-clutch transmission), it was only a vague idea, and it was not until the end of the 90s that it was really practical.

As for the CVT (continuously variable transmission), Belgium's Bunge Company introduced a practical metal belt continuously variable transmission (VDT-CVT) in 1974, but because the torque of the CVT is too low, not many passenger cars use it.

AT, AMT, and Tipertronic have been firmly occupied by manufacturers in Europe, the United States, and Japan, and have established high technical barriers, and it is difficult for other manufacturers to enter. Therefore, in order to gain a place in automatic transmissions, it is necessary to find another way.

According to the development history of automatic transmissions, there are only two options that Ling Shizhe can choose - TCD and CVT.

After thinking about it, Ling Shizhe finally wrote TCD on a piece of paper.

"What's the boss, you're going to do this?" Alison said with a frown.

Ling Shizhe nodded and said, "Yes, DCT is already doing it, it's better to just continue." Others, such as AT and Tipertronic, have long been occupied by those big manufacturers, and we have to find another way. ”

"But have you ever thought that there is no DCT, it is still just a theory, and the technical difficulty of TCD is quite large, which is not comparable to motorcycle transmissions."

"I thought about it, and DCT was our only chance." Ling Shizhe said categorically.

No matter what kind of automatic transmission, it will touch the patents of those predators, which will attract their strangulation, but it will not engage in DCT, because the DSG gearbox is obviously different from the traditional automatic transmission, and the DSG did not use a hydraulic torque converter from the beginning.

Rather than being based on a traditional concept of automatic transmission, the engineers who designed the DSG took a completely new and innovative technological path, cleverly combining the flexibility of a manual transmission with the convenience of a traditional automatic transmission. Therefore, the development of DCT will not touch the patented mines planted by traditional transmission predators.

In addition to the above reasons, another reason is also the key factor for Ling Shizhe to decide to develop DCT, that is, the entire working process of DCT is controlled by the computer, which is a typical intelligent transmission, and others dare not say that the computer is Ambrella's strength, whether it is a project or a product development, it must do what it is best at, so whether it is AT, Tiptronic or CVT, it is not what Ambrera is best at. On the contrary, DCT is the best place to take advantage of Ambrera's computer technology.

In the 21st century, with the higher and higher oil prices and the more and more stringent exhaust emission standards of various countries, as well as the concept of environmental protection, the future automobile engine can only be more and more miniaturized and less cylinder direction. Like the eighties of the 20th century, the configuration of six-cylinder, eight-cylinder, or even twelve-cylinder can only appear in the configuration of luxury cars.

As a means of transportation for ordinary families, family cars generally only need four cylinders, or even three cylinders. So the engine engineers racked their brains, developed a variety of technologies, and constantly improved the engine, almost all kinds of applicable technologies have been used in the four-cylinder engine, the potential of the engine has been improved to a certain level, it is already difficult to break through the situation.

At this time, the competition between international automobile manufacturers should be considered from another aspect of the powertrain, the transmission.

There are only a few types of automatic transmissions for automobiles, such as AT, AMT, CVT, and DCT.

As a reborn, Ling Shizhe undoubtedly has the clearest and most intuitive judgment on the development trend of future automotive transmissions.

First of all, AMT and CVT, the two automatic transmissions, have been eliminated in Ling Shizhe's eyes, although they both have their own advantages, but the disadvantages are equally obvious.

Although AMT is more fuel-efficient, it has a strong frustration of shifting, and its electronically controlled shifting, as well as the clutch part, are particularly easy to damage, and the maintenance cost is also very high, so it has not been popularized on a large scale.

CVT has been popular in the automotive industry for a while, and its advantage is obvious, that is, it uses the chain transmission mode of the bicycle to work, so there is no transmission gear in the gearbox, so there is no frustration when changing gears, and the fuel consumption is smaller than other transmissions, and the noise is low.

But its shortcomings are also fatal, first of all, in the starting or acceleration stage of the car, the metal chain or belt as the transmission torque is easy to slip, and generally after 50,000 to 100,000 kilometers, the chain or belt needs to be replaced.

Moreover, the CVT gearbox is prone to problems, and once it goes wrong, it is a big problem, and it is very expensive to repair.

AT is a transmission that automatically shifts gears through hydraulic pressure, when the engine is working, the horsepower will drive the hydraulic pump wheel, and the pump wheel will make the liquid in the gearbox circulate quickly, and the circulating liquid will drive the turbine in the gearbox, and the rotation of the turbine will eventually drive the guide wheel, and the guide wheel can make the outside car wheel rotate, so as to complete the power output to the outside world.

At present, AT technology has basically reached the mature stage, and it will continue to be the mainstream of automatic transmissions in the future. The disadvantage is that it consumes fuel and the frustration of shifting gears is strong, so that the driver does not feel too much fun driving.

Compared with the traditional automatic transmission, DCT has too many advantages, is the most ideal transmission development direction in the future, it combines the advantages of manual transmission and automatic transmission, does not use torque converter, uses two sets of automatic control clutch, through the two sets of clutches alternate work, to ensure that the power output will not be interrupted, and then to achieve the effect of backlash shifting.

Two sets of clutches are respectively connected with solid drive shaft and hollow drive shaft, solid drive shaft is connected with odd gear and reverse gear, hollow drive shaft is connected with even number of gears, specifically before shifting, DSG has meshed the next gear gear in advance, after getting the shift instruction, DSG quickly sends a command to the engine, the engine speed increases, the gear of the previous meshing is quickly combined, and the first group of clutches is completely released at the same time, and a upshift action is completed, and so on.

Due to the elimination of the torque converter, the power output of the engine can be fully utilized, and by alternating the two sets of clutches, the time to change gears is reduced, and the interruption of the power output of the engine becomes very limited. In this way, the driver does not have the slightest frustration during the driving gear shift, and at the same time, the dynamic performance of the vehicle is fully exerted.

As a result, compared to conventional automatic transmissions, the DCT dual-clutch transmission shifts more directly and the power loss is reduced, so fuel efficiency can be improved by more than 10%.

Although there are many advantages of DCT, it is not without its disadvantages, because the use of torque converters is abandoned, but the "semi-linkage" state of manual transmissions cannot be realized, so that the characteristics of small displacement engines with insufficient torque at low rpm are fully exposed.

Second, DCT is an intelligent transmission, which requires a large number of electronic components, and the working environment of the automobile transmission is extremely harsh, which will increase the failure rate and the difficulty of repair.

Therefore, low-end small-displacement passenger cars are not suitable for installing DCT dual-clutch transmissions.

But give up the low-end car market Ling Shizhe is very unwilling, you must know that although the price of low-end passenger cars is not high, car companies make money on each car, not as much as high-end cars, but low-end passenger cars have the largest car market share.

In later generations, Toyota produced more than 12 million cars annually and became the world's largest car manufacturer, relying on low-end small-displacement cars, and low-end small-displacement cars are also the largest source of profit for automobile companies.

How many low-end cars are consumed in the world every year? Ling Shizhe did not know the statistics, but he knew that it was definitely an astronomical figure, after the development of China's automobile market in the 21st century, the annual consumption of low-end cars will reach a new high, therefore, the automatic transmission used in low-end cars must have broad prospects, and it is a pity to give up.

But DCT is inherently not suitable for low-end cars, and it seems that in addition to DCT, you have to find another transmission.

But what kind of transmission is suitable for low-end and small-displacement passenger cars? CVT, Ling Shizhe gave it no for the first time, don't look at the cars made in the Republic of China in later generations, most of them use DVT gearboxes, but the maximum torque of CVT is too small, and CVT is not suitable for China's national conditions, the reason why China has adopted a large number of CVT in later generations is that the fundamental reason is the technical blockade from Western countries, so China's own domestic car brands can only choose CVT, if there is a choice, that will choose it.

Transmissions used in low-end and small-displacement passenger cars must meet the characteristics of low price and low maintenance costs.

According to this standard, after Ling Shizhe searched in his mind, he really found it - emt.

The EMT was developed by General Motors in 2009.

It is based on the traditional manual transmission car, does not change the structure of the automobile engine and transmission, and uses the electric motor as the external actuator of the transmission.

Strictly speaking, EMT is an AMT transmission with upgraded functions, that is, ECU is installed on the basis of the traditional AMT to achieve the purpose of automatic transmission. During operation, the ECU replaces the entire process of manual gear change by means of an electric mode.

It has the advantages of low transmission energy consumption, high power transmission efficiency, low cost, simple structure, low maintenance cost, and mature products, so it is very suitable for low-end and small-displacement passenger cars.

AMT appeared as early as the 50s and has long passed the patent protection period, so Ling Shizhe does not need to worry about infringement and can use it directly.

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