Do trucks need dual clutches？ I really want to use these points!

[Truck House Original] Recently, we saw a set of data on the live broadcast of a press conference. In the heavy commercial vehicle market in 2019, about 8,000 vehicles equipped with AMT automation were sold. By 2020, nearly 50,000 heavy commercial vehicles equipped with AMT gearboxes have been sold, showing almost explosive growth.

The outbreak of automatic transmission has attracted the attention of manufacturers.

The explosive growth of automatic heavy trucks not only makes more card friends choose automatic transmission models, but also makes all manufacturers aim at this field. To put it simply, in the eyes of manufacturers, this thing can be sold and sold for more money, then they will invest in research and development and make this thing. The more R&D is invested, the more ways to realize automatic transmission, or the more R&D routes.

And the live broadcast we saw came from the international gearbox, or the transmission system giant Borgwarner. The theme of this live broadcast is how promising it is to use the dual-clutch gearbox in commercial vehicles, and what kind of experience it will bring.

To put it simply, Borgwarner, as a giant in the transmission system manufacturer, has targeted the market of truck dual clutch. Judging from the participating brands, many domestic truck brands also recognize this matter. It can be said that they have reached a consensus.

So what’s the difference between dual-clutch gearbox and AMT now? Let’s have a brief talk first.

What’s the difference between dual clutch and AMT now?

In fact, the essence of dual clutch and AMT is manual gearbox, but AMT operates the gearbox through gear selection computer and actuator. The dual clutch is to subdivide it again, so that two sets of actuators are responsible for odd gears and even gears respectively. For example, if you are hanging the third gear now, then the actuator of the third gear is working. But at this time, the 4-speed actuator with dual clutch is already ready there. When we need to shift gears, it will switch between two sets of actuators.

We can understand that AMT is equivalent to adding a gear selection computer and a set of electronic control actuators to the manual gearbox. The dual clutch gearbox is to install two AMT in the car. The usual shift is to operate between two sets of actuators. In this way, the shift of the dual clutch can be faster, and the power loss caused during the shift process will be smaller. More fuel-efficient, more powerful, and the cost has not increased much.

There is still a long way to go, and it still needs hard work for the dual clutch to gain a foothold.

In fact, the appearance of dual clutch on trucks is undoubtedly a good thing. But after all, it also has shortcomings. If you want to really gain a foothold, according to Xiaobian, it is almost interesting. At least what I say below needs to be changed or satisfied.

1, the price is the key!

Compared with the AT gearbox, which now occupies a dominant position in passenger cars, the dual clutch is derived from the manual gearbox, and the cost is inevitably lower. However, compared with AMT gearbox, it is more complicated, so the cost is still rising.

To tell the truth, it is difficult for freight card friends to survive now, and buying AMT models is already biting their teeth. At this time, a dual-clutch model that is more expensive than it comes out, and the card friends will definitely not accept it. And this is likely to directly end the life of the dual clutch.

2. It is a problem that large torque is difficult to match.

As we mentioned earlier, the dual clutch gearbox is equivalent to an AMT with two sets of actuators. But in the car, everyone knows that the gearbox can’t be too big and too heavy. Therefore, the dual clutch gearbox often integrates two groups of clutches, which leads to a sharp reduction in the volume of clutches in the dual clutch.

The torque that a small clutch can bear is limited. On the live broadcast of this conference, relevant experts directly gave suggestions: dual clutch gearbox, suitable for power chains less than or equal to 1250 Nm. This also makes the dual clutch gearbox bid farewell to many models directly, especially for some trunk logistics that need high-end, the dual clutch has basically been out.

Of course, it is not without application in high-torque models, for example, it provides a dual-clutch version with a maximum of 540 horsepower. According to the industry bull, if the dual clutch of commercial vehicle adopts the form of front-inserted dual clutch, it will have direct structural difference from the dual clutch of passenger car today, so its performance will be different. It is not certain whether domestic manufacturers will choose this technical route if they apply it.

3, durability may be insufficient!

When the clutch plate becomes smaller, its heat dissipation capacity will become worse, and the heating speed will be much faster. This is equivalent to not only limiting its own strength, but also burying the hidden trouble of failure.

Let’s put it another way. In Xiaobian’s 6 years of experience in passenger car media, I have tried countless passenger cars with dual clutch gearboxes. These vehicles have left a bad impression on me more or less during their use. It can be said that the dual-clutch gearbox is not perfect in passenger cars, whether it is a setback in the acceleration process or an abnormal sound under long-term traffic congestion.

We have to put a question mark on the durability of this clutch gearbox in commercial vehicles that are heavily used and bear greater torque.

4, not smart enough is a serious injury!

In addition to the above problems, commercial vehicles, especially heavy trucks, have more gears in their gearboxes, and we often need to downshift frequently when we slow down. However, limited by the principle, the dual clutch gearbox cannot be trip stop. Because the odd gear is hanging, the next shift must be the even gear.

When we slow down or encounter congestion, vehicles often choose different gears according to the degree of deceleration. At this time, the dual clutch gearbox may not be smart enough to hang the gear we need most. And this problem is also the key. You said it was possible to make up for it with its fast shift speed. However, rapid gear shifting will inevitably exert greater pressure on the gear and box structure, which may also increase the failure rate.

● Editor’s note:

Therefore, if the dual-clutch gearbox really wants to be popularized and go to thousands of households, it still needs to overcome many problems. But I believe that once these problems are overcome, the dual-clutch gearbox will definitely bring us a better experience. (Text/Yuan Sheng)