The middle axle and the full trailer look very similar, in fact, the difference is very big

With the gradual increase of the national governance of ultra-long car and van, more and more models of the middle axle, which is still a new thing in China, have appeared in front of us. What are the advantages and disadvantages of this car? How is it different from a traditional full trailer? This is one of the several problems that owners are most concerned about.

● All the front axle steering is unstable astern trouble

I believe that when many old owners first saw the middle axle car, the first reaction was dismissive: "Cut, this is not the full hang that I drove!"

In fact, the whole trailer is mainly composed of carriage, axle, bogie and traction device, of which the front axle and bogie and traction device are combined as a whole, which can be turned with the driving direction of the tractor; In addition, the traction device can trailer axle be moved up and down, and because of this, the tractor only plays the role of traction, and does not bear the weight of the trailer, so the trailer can not rely on the tractor to "stand" on the road.

Of course, the disadvantages are obvious, and it is very troublesome to reverse the car. The driving skills of the driver are extremely demanding, even several orders of magnitude more difficult than the semi.

However, the number of full trailers is now very rare, after the 1990s, with the improvement of road facilities, as well as the development of expressways, the problem of poor stability of full trailers has gradually become prominent. Eventually, it was banned from highways. Now, except for a few areas of Inner Mongolia can still be seen, the rest of the area has basically disappeared.

● Middle axle is more stable and easy to reverse

In contrast, the current rising star center axis, although the appearance and the full hanging is very similar, but it is completely different. First of all, its axle is concentrated in the middle of the carriage, secondly, it does not have a bogie, and the traction device cannot be moved up and down. Because of this, part of the weight of the middle axle trailer must be borne by the tractor, and once it leaves the tractor, the trailer will lose its center of gravity and "collapse" on the road.

Overall, the middle axle is more like a semi-trailer, so it will be much easier to reverse than to fully hang.

GB1589-2016 also has a clear definition of the center axle trailer:

1. The traction device cannot have the ability to move up and down like a fully hung traction device;

2. The axle position is close to the center of gravity of the trailer (when parked alone, the trailer will lie down);

3, the weight of the traction device transferred to the tractor trailer axle does not exceed 10% of the total weight of the trailer or 10000N.

Then compare the characteristics of the full trailer:

1. The axle is distributed at both ends of the car body and parked stably;

2, the front axle with bogie, can be turned with the tractor;

3, the traction device can move in the vertical direction;

4. Bear all the weight of the vehicle by itself.

In addition, the middle axle model in terms of driving stability is unmatched trailer axle by the full trailer, it can legally drive at high speed. Even in the face of the semi-trailer that is now flourishing, the center axle also occupies a favorable position, and GB1589-2016 clearly stipulates that the total length of the flat-headed semi-trailer shall not exceed 17.1 meters; Long head semi-trailer shall not exceed 18.1 meters; The total length of the mid-axle van does not exceed 20 meters; The total length of the mid-axle coupe has been extended to 22 meters. Therefore, the goal of the emergence of the mid-axle model may be to replace the excess car and the sedan.