Why Japanese cars just don't need dual clutches?

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Indeed, in recent years, the dual clutch of many models has really sold crazy, especially the domestic automatic transmission cars seem to be thinking of a curse, and they all use the dual clutch. There is a joke on the Internet mocking the dual clutch: "How to play? Wet is enough. "

However, ridicule is ridiculous, even if the double clutch is re-ignited, it seems that they are not interested in small Japan. In their world, CVT is still king. There have been many related introductions about dual clutch on the Internet. Here's a car hot review to simply repeat its principle and characteristics.

Dual-clutch gearbox: Simply put, it is composed of two groups of clutches, and two drive separation bearings control their respective clutch plates. When one clutch is in working state, the other clutch is in standby state at any time. Double clutch can basically realize seamless connection of power and run smoothly. Because there is no hydraulic torque converter, the power loss in the transmission process is small, thus greatly improving the fuel economy of the vehicle.

The disadvantages of dual clutch are not only low speed, frequent acceleration and deceleration, but also slightly worse stability than at gearbox, especially dry dual clutch. Although CVT gearbox is widely used in Japanese cars now, it was invented in the Netherlands in Europe.

After the invention of CVT, Audi, BMW, Fiat and other car companies also tried it, but CVT was basically abandoned by European car companies, mainly due to some embarrassment of CVT itself. For example, CVT is not suitable for vehicles with large torque and large displacement, and European brands such as Audi and BMW also have very good adjustment level in dual clutch and AT technology, so CVT is a bit tasteless in their eyes.

As the saying goes, "A good horse with a good saddle", even a good swift horse needs a Bole, and the Japanese are Bole of CVT gearbox. We all know that Japanese people are very careful in their bones. Especially after K-Car is popularized in Japan, CVT, which is suitable for small displacement, economy, fuel saving, low cost and smooth driving, is more in line with its positioning in the hearts of Japanese people.

Unlike Europeans and Americans who pursue control, power and driving pleasure, Japanese people pursue fuel economy, ride comfort and ease of driving. After the Japanese found a good horse CVT, CVT can be regarded as a flower in the hands of Japanese car companies with the spirit of Japanese Excellence, and its quality and performance have been further sublimated. Under the premise that major car companies around the world are increasingly pursuing energy-saving emissions, the characteristics of CVT have been amplified.

More importantly, the CVT technology in the hands of Japanese car companies is now in full swing, and the power output is not lost to the traditional gearbox. Coupled with its smoothness and low cost, the Japanese obsession with CVT will continue.

Dual clutch is really popular at present. Some models made in Germany, USA and China tend to use dual clutch. However, Japan has never been interested in dual clutch. In fact, I don't think Japan will study dual clutch technology. The main reasons for its slow action are as follows:

Compared with AT and CVT in Japan, 1 and dual clutch have no obvious advantages.

The main advantage of dual clutch is fuel economy, and for Japanese cars, the main feature of cvt gearbox is also fuel economy. Taking Volkswagen Sagitar and Honda Civic as examples, compared with Sagitar 1.5T matching CVT Civic and Sagitar 1.4T matching dual clutch, the fuel consumption is lower, and the fuel consumption of Sagitar 1.4T Ministry of Industry and Information Technology is 5.9L/65438+.

From the comparison of acceleration ability, the Civic with 0- 100 acceleration is 0.5 seconds faster than that with1.4t. Of course, the output power of the Civic turbocharged engine is higher.

As can be seen from the above comparison, DSG is not superior to CVT in fuel consumption, and the actual acceleration ability may not have much advantage. At present, the torque that CVT can bear can reach 450 Nm, which is more than enough even for a 2.0T turbocharged engine. Subaru Forester 20 12 uses CVT to match 2.0T engine, and the acceleration time of 0- 100 has reached 6.8 seconds.

2. Japan's own industrial chain of AT and CVT is very mature.

After years of development, Japanese cars have their own mature gearbox production system, with AT as the main part in the middle and high end and CVT as the main part in the middle and low end. Japanese manufacturers either produce their own gearboxes, such as Mazda and Subaru, or jointly establish a gearbox factory. For example, the gearbox produced by the famous Aisin and Jetta Gatt is mainly supplied to Toyota and Nissan. From the perspective of development, it is unlikely that Japan will abandon mature at and CVT to play immature DCT in a short time.

3. At present, there are still some shortcomings in dual clutch technology.

Because friction is used to buffer the impact between gears, dual clutch gearbox has certain requirements on the material of clutch plate and shifting logic, and heat dissipation is more important. Although Volkswagen has basically solved the heat dissipation problem after more than ten years' development, the dual-clutch low-speed shifting has regressed to a certain extent, which can be verified by many models from the initial use of dual-clutch to the quiet switch back to 6AT.

4, the cost of double clutch

The cost of dual-clutch gearbox should actually be higher than 6AT now, and it can't compare with CVT in any case. For a small Japan that is good at budgeting, it is definitely not possible to change the dual clutch easily.

5. The future technical route of Japanese cars-hybrid power.

In fact, the technical route of Japanese cars in the future is the so-called "double-engine strategy", with CVT for low-end models and hybrid for mid-end models to match ECVT. These technologies have nothing to do with dual clutch.

6. Future

There is still a lot of room for improvement in the dual clutch. However, the technical scheme of the automobile is to comprehensively consider the market positioning, fuel consumption, durability and acceleration ability of the automobile. Not using it now doesn't mean not using it in the future. Just like the turbocharged engine, it was delayed in Japan and suddenly adopted in large quantities around 20 15. This is actually based on environmental protection and market considerations. Do Japanese cars use dual clutches? In fact, Japanese cars also have dual clutches, but they don't use them a lot!

By the way, the dual clutch used by Honda Platinum Core is no longer a dual clutch. This gearbox is a grafted product. The front part adopts hydraulic torque converter (not two sets of clutch plates), and the principle of the rear part is the same as that of the dual clutch structure.

Today in 2020, not only German brands, but also domestic independent brands including Geely and Chery are using the dual clutch gearbox (DCT). Japanese cars, which are also powerful automobile manufacturers, are rarely related to dual clutches. They use AT and CVT gearboxes more, which makes many people wonder. Why can't powershift attract Toyota Honda's love because of its fast shifting and high efficiency?

As the name implies, the dual clutch gearbox has two sets of clutches. When one clutch is in working state, the other clutch is in standby state at any time. They cooperate with each other to realize seamless power transmission, and there is no power loss caused by hydraulic torque converter in AT transmission.

It looks good, but there may be some problems.

Due to its special structure, the dual-clutch gearbox is particularly prone to setbacks at low speeds. Now, when the technology is not very mature, the probability of failure is relatively high. Everyone knows that Japanese-made cars, especially Toyota and Honda, are notoriously reliable and durable. This is the core concept of their car. They are very cautious about the use of less reliable technologies. For example, for so many years, the gold-lettered signboard was equipped with a dual-clutch gearbox, and unexpected faults and problems appeared. Isn't this smashing your own signboard?

If one day the dual clutch gearbox technology is mature and stable to be similar to CVT and AT, I think the large-scale assembly of Toyota Honda is just around the corner.

Some places are beyond CVT's power.

CVT gearbox can realize stepless speed change and power transmission is very smooth, but one thing is unacceptable to European car companies. European car companies such as Mercedes-Benz and BMW are more or less fond of building many high-performance cars with high torque and high speed. However, the steel belt of CVT is rejected by many high-powered cars because it cannot bear too much torque through the meshing of gears. In addition, under the research and development of German car companies for so many years, the shortcomings of dual clutch are slowly improving. In their view, CVT is completely chicken ribs.

The structure of CVT gearbox is much simpler than that of dual clutch, and there is no complicated electronic mechanism. Even if it is broken, it is very convenient to maintain and the cost is much lower.

abstract

Whether Japanese cars like to use CVT or more stems from their concept of building cars, and sometimes they sacrifice the so-called sense of technology to pursue reliability and stability. For example, Honda's earth dream engine, Toyota's TNGA architecture, and even Mazda's blue sky technology all represent the Excellence and persistence of Japanese cars in technological change. Only Japanese cars can apply a technology to the extreme. This is a kind of persistence, and it is also an infinite exploration of the respect and potential of technology.

First of all, is the dual clutch selling crazy? I don't think so. Judging from the current market, the sales of dual-clutch gearboxes are mainly German, and most of them come from the sales of German cars, such as Volkswagen dsg. Because of the large sales volume of Volkswagen, dsg gearboxes can occupy a part of the market. In addition to Volkswagen, many Japanese cars also use dual clutch gearboxes. At present, some domestic cars have begun to follow suit and embark on the road of dual clutch. In fact, the dual clutch ability of each family is different. Let's discuss what dual clutch is.

Dual clutch: Dual clutch gearboxes are divided into dry and wet types. Let's talk about the difference between dry and wet: dry double clutch means that the clutch of the transmission is in a relatively dry space, which has the advantages of low cost and simpler structure; Disadvantages are that the clutch is dry-ground, the torque it bears is not very large (it can't match the engine with too large torque output), and the clutch frequently moves and semi-hangs, which is easy to overheat (the typical situation is the stop-and-go traffic jam environment).

As we know, most German cars and self-owned brands use dual-clutch gearboxes. American cars also used dual clutch for some time, but it is rarely used at present. However, Japanese cars rarely use dual clutch gearboxes. Why do German cars and our own brand cars prefer dual-clutch gearbox, while German cars don't use dual-clutch gearbox?

Before talking about why Japanese cars don't use dual clutch, let's talk about why German cars and independent brand cars prefer dual clutch. As one of the three major components of automobile, the development difficulty and cost of gearbox are no less than that of engine. We can see that many manufacturers can produce engines, but not necessarily gearboxes. Since you don't produce gearboxes yourself, you need to buy someone else's gearbox, which will definitely increase the cost of building a car. In order to reduce the cost of building a car, we will develop the gearbox ourselves, but the gearbox development has patent protection. It is still difficult to bypass the patent to develop at or cvt gearboxes.

Therefore, German cars have taken a different approach and developed a dual-clutch gearbox. German cars have also taken many detours in the process of developing gearbox, and many problems have appeared. Since the use of DSG, Volkswagen's reputation has been much worse, but now there are fewer and fewer problems. At present, the dry dual-clutch gearbox still has the problem of frustration and fever, but the wet dual-clutch performance is very stable. At present, the low-profile models in Germany will adopt dry dual clutch, while the high-profile models will be equipped with wet dual clutch. As for the reason, it must also be based on cost considerations. The main reason why our own brand cars use dual-clutch gearbox is that the field of dual-clutch gearbox is relatively blank and there is not much patent protection.

Let's talk about why Japanese cars rarely use dual-clutch gearboxes. Japanese cars don't need a dual-clutch gearbox. The biggest reason is that there is no need to use a dual-clutch gearbox at all. As we know, Tektronix, ZF and Aisin are the three largest gearbox factories in the world, two of which are from Japan. Japanese gearbox has a complete supply system. Nissan is a shareholder of Tetek and Toyota is a shareholder of Aisin. Mazda and Honda can develop gearboxes. Japanese cars either have a stable gearbox supply system or can independently develop at or cvt gearboxes. Naturally, there is no need to develop a dual clutch gearbox. Moreover, the dual clutch gearbox also has some problems. American cars such as Fox also gave up the dual-clutch gearbox and adopted a more stable at gearbox.

In addition to at gearbox, cvt gearbox is also widely used by Japanese cars. Whether Toyota, Honda, Nissan or Subaru will use cvt continuously variable transmission. The CVT continuously variable gearbox has smoother and more linear power output, stable and reliable quality, and gives consideration to fuel economy, which conforms to the concept of Japanese cars. The advantage of dual-clutch gearbox is that it has fast shifting speed, which is more in line with the concept of German cars pursuing sports and handling. Porsche, Audi and BMW all use dual clutch gearboxes. Nissan Ares gtr also uses a dual-clutch gearbox, which also pursues extremely fast shifting speed and handling.

It's not that Japanese cars don't need a dual clutch gearbox, but it's totally unnecessary.

You only saw the hot market of dual-clutch gearbox, but didn't think of the reasons behind it. Why do many domestic cars and German cars use dual clutch gearboxes now? Because the cost is low and the technology is simple, there is no need to pay the technology patent fee.

You know, most of the patents of at gearbox and CVT gearbox are in the hands of three gearbox giants, namely, Jakot, ZF and Aisin. Other car manufacturers have to pay high technology patent fees every year, which is also the reason why car prices have not come down before.

The dual clutch gearbox is based on the traditional mechanical gearbox with a clutch and an electromechanical unit. At the beginning, as long as Volkswagen tried it alone, the DSG dual-clutch gearbox technology of rear-wheel Volkswagen was mature and acceptable to consumers, so many automobile manufacturers began to follow suit and put on dual-clutch gearboxes.

Why are so many brands on the market using dual-clutch gearboxes, while Japanese cars don't? The reason is unnecessary. You know, two of the three major gearbox brands in the world are Japanese. Toyota owns more than 20% of Aisin, Jecott owns 75% of Nissan, Mitsubishi owns 65,438+05% and Suzuki owns 65,438+00%.

Therefore, these Japanese cars with the largest share in China will naturally use their own gearboxes. After all, the technology is so mature and users like it, so why go to the dual-clutch gearbox that users don't like?

As for Mazda, one of the Japanese brands, it has its own insistence. They also have their own gearbox factory. Although it is not very famous, it matches its model very well. AT gearboxes bear large torque, and many professional off-road vehicles are AT gearboxes.

So these factors make the dual clutch gearbox so popular. Why don't Japanese cars directly use dual-clutch gearboxes? If you have other opinions, please give me your opinions.

Quite simply, the Japanese are betting too much on CVT and AT, and the supply chain is closed, so it is difficult to get out. On the surface, Japanese car factories are not enterprising, which is actually caused by their rigid supply chain and rigid system.

First of all, Japan is mainly a K car with a displacement of less than 0.66 liters. This mini-car has small power, light body and slow running, so CVT is also a good choice. Therefore, CVT, which is still fuel-efficient but has poor performance, has become an important choice for Japanese car companies.

Secondly, Japanese cars are relatively strong in Japan and the United States. For Japanese automakers, larger cars have been used for many years. Moreover, the American market environment is not sensitive to new technologies, and the acceleration is mainly achieved by large displacement, so the Japanese have been betting on AT.

Due to the closed supply chain characteristics of Japanese car factories, it is difficult to respond quickly to new technologies. The car factory can only use the CVT and AT that the fixed supporting factory already has, and everything is stable. Supporting plants and main engine plants are not enterprising, but only do it.

As a new and most promising automobile transmission technology, dual clutch has a growing camp and stronger strength. It has obvious advantages over the traditional gearbox in driving experience and fuel saving. However, the Japanese did not want to see the coffin and shed tears. Early resistance to turbocharging, now resistance to dual clutch. However, as seen in the turbocharging, the Japanese will bow their heads sooner or later. I haven't seen Toyota talking about driving experience now, learning from Germans!

Not only does Japan not adopt dual clutch, but even turbocharged engines are not going to adopt it. However, due to the global emission pressure and the strict demand for displacement in the domestic market, turbocharged engines have to quit. I don't think Japan will develop a dual clutch gearbox in the future. The reason can be summarized as follows: the Japanese are very strict and cautious about the application of technologies with weak reliability, which also confirms why CVT has been used by the Japanese for a long time. For example, Honda's Earth Dream Engine, Toyota's TNGA architecture, and even Mazda's Chuangchi Blue Sky technology all represent the technological research and development strength of Japanese Excellence, and only Japanese can apply a technology to the extreme. This is a kind of persistence, and it is a respect for technology and unlimited exploration of potential.

Dual clutch gearbox is the Chinese translation of powershift (DCT), and so is Volkswagen's DSG. Through the seamless connection of two sets of manual transmission clutches, he realizes the purpose of fast gear shifting. It is divided into two specifications: dry double clutch and wet double clutch. The advantages of dual clutch are self-evident: fast shifting will reduce the loss of engine output power, thus achieving the purpose of reducing fuel consumption. However, its defects are also very obvious: insufficient torque is infinitely amplified at low speed, and complicated internal structure+electronic components bring inevitable high failure rate.

What are the advantages of CVT gearbox commonly used in Japan? CVT should be one of the most ideal automobile gearboxes at present. The biggest advantages are: simple structure and extremely low failure rate; High quality brings the life-long maintenance-free characteristics of the same life as the car; There is no gear, the speed change process is continuous and linear, and there is no shift impact when speeding up, which brings the ride comfort of the whole driving process; The transmission of power performance is obviously superior to manual transmission (MT) and automatic transmission (AT). The more economical fuel consumption performance is far better than other gearboxes. Japanese brands' love for CVT gearboxes also allows more consumers to buy their products with confidence, and the frequent double clutch failures of Volkswagen, Audi and other brands also reflect the fact that Japanese companies are determined not to adopt double clutches.

In fact, there is a good thing in this world, called hydraulic torque converter.

I'm not talking about black people here, but without comparison, it won't hurt, right? This paper will adopt Volkswagen dual clutch.

Compare Honda dual clutch. Only for the comparison of two cars in low-speed crawling road conditions.

Honda Spiro is also a dual-clutch gearbox, but the difference with Volkswagen dual-clutch is that Honda dual-clutch is additionally equipped with a hydraulic torque converter (the soul of automatic gearbox, the starting artifact). Speaking of Volkswagen, because Volkswagen DSG is not equipped with hydraulic torque converter, the low-speed crawling, low-speed starting and ramp starting of Volkswagen are all rubbish.

In a word, the whole Volkswagen Group can't make a decent hydraulic torque converter.

Nissan GTR's dual clutch, the city traffic jam is also very fucked up, a car owner said that he is the owner of GTR. Because Nissan dual clutch does not add hydraulic torque converter, it crawls at a low speed like Volkswagen, which is very fucked. As for how GTR performs at high speed, it must be fast and accurate. Unfortunately, today we only discuss the low-speed crawling road conditions of urban traffic jams.

In contrast, Honda's dual clutch and low-speed crawling can be comparable to AT gearbox, because both it and AT are equipped with hydraulic torque converter. Volkswagen's dual clutch crawls at a low speed, and its performance is very poor. Because Volkswagen dual-clutch cars don't have hydraulic torque converters.

If it is greater than the category, dual clutch VS CVT VS ordinary AT, that is another big topic, which will be discussed later.

Comparison of two categories

Dual clutch and traditional 6AT. (As mentioned above, all AT cars have more torque converters than DSG)

The definition of dual clutch, 135 gear shares a shift clutch, and 246 gear shares a shift clutch, so there are only two clutches in total (this word is very important), so it is named dual clutch.

Well, let's look at the traditional 6AT. Each gear has a clutch, so the full name of 6AT is called six-clutch gearbox (this gearbox also has at least six clutches, because each gear has a clutch, is it a luxurious feeling). The traditional gearbox of 10AT has one clutch in each gear, so it is called ten-clutch gearbox. (Does it sound higher than dual clutch? )

A well-trained AT, such as Mazda's 6 AT (gearbox with amazing shifting speed, tuned by Aisin hardware and Mazda's software), shifts faster than all gearboxes in Volkswagen's home, and it should be said that it is faster than any car on the market. The AT trained by Mazda is crazy. Volkswagen's double clutch, well set-up. And Jeep Freeman's dual clutch training is not worthy of giving shoes to the public.

Conclusion:

Volkswagen DSG is not bad, but it has the biggest slot-there is no hydraulic torque converter, and traffic jams in urban areas are painful, which is not as comfortable as Honda dual-clutch cars.

What I said has nothing to do with Japan and the Japanese devils, only things. CVT means uninterrupted power and stepless speed change. Uninterrupted power means fuel saving (no empty oil) and no setbacks. Stepless means that the engine can work in the most fuel-efficient speed range at all speeds. This is the ultimate ideal of all transmission! ! ! ! In principle, the double clutch is to reduce the shift time, and force two working faces with different speeds to join together by sliding friction plates. You got it? From a larger perspective, from the United Nations classification and ranking of industrial categories, Japan has completely defeated Germany in all fields, with complete categories. As far as transmissions are concerned, it is an indisputable fact that Volkswagen has adopted a large number of Japanese transmissions outside China. The subject is playing dumb!