On September 21, 2016, the release of the new standard brought China's logistics industry to the cusp of change, and the mid-axle trailer also began to enter people's field of vision from this time.
According to the provisions of GB1589-2016, the total length of the mid-axle car for general cargo can reach 20 meters, and the mid-axle car can reach 22 meters. But GB1589-2016 has been released for nearly 8 years, except for the mid-axle car, why do we rarely see the mid-axle general cargo vehicle?
The semi-trailer is to connect the front part of the trailer with the tractor drive axle position, and a part of the downward gravity after loading is shared by the tractor, that is to say, the connection force between the semi-trailer and the tractor is not only transverse force, but also longitudinal force. This means that when carrying the cargo, the weight is shared by the tractor and the trailer, which makes the semi-trailer run very smoothly. Although the "tail flicking" of semi-trailers can also occur in relatively extreme cases, the "tail flicking" of semi-trailers
It is basically horizontal, the tires are completely attached to the ground, and the probability of the vehicle rolling over is relatively low.
After the central axle trailer is loaded with goods, the weight of the goods is all pressed on the trailer, and the tractor has only one forward traction force on the trailer, and the trailer is not divided into any weight, so the vehicle is in the process of driving, and the tractor only has forward traction for the control of the trailer, so in the case that the trailer encounters cross wind or uneven road surface, the trailer may have a "pendulum effect". Compared with the side slip and tail flick of the semi-trailer, the "pendulum effect" is more difficult to control, and it may implicate the "pendulum effect" of the tractor and cause overturning.
In fact, when the mid-axle model was first implemented in 2016, most cardholders lacked driving experience because they had not driven a mid-axle trailer, and accidents occurred frequently.
Compared with semi-trailers, there is also a disadvantage of the mid-axle trailer - the trailer must be disassembled every time it is loaded and unloaded (here we are talking about ordinary trucks, the car does not need to be disassembled, and the front and rear can be communicated through the bridge).
Generally, the central axle trailer is a closed van, loading and unloading to pass through the back door of the carriage, loading and unloading when the trailer needs to be leaned against the platform, and then the trailer is removed, and then the main car compartment is leaned against another platform, which is the loading and unloading mode of the European central axle trailer. However, the loading and unloading of goods in domestic logistics parks is generally a single vehicle, which means that the trailer needs to be unloaded on the trailer after the platform, and then the trailer is towed to an open place, and then the main vehicle is unloaded by the platform, which is very cumbersome and takes a lot of time.
At the same time, the connection coupler of the central axle trailer is generally spherical and duckbill type, and the strength of connecting the central axle trailer is no less than the connection strength of the semi-trailer, and all the processes are the same as a lot - it is necessary to shake the outriggers, plug and unplug the wiring harness pipeline, open and close the traction pin lock switch, and the labor intensity of this set has increased a lot.
In addition, the total length of the central axle trailer can reach 20 meters, and the main vehicle of the central axle trailer is a truck, the wheelbase is longer, and the turning radius is also larger than the semi-trailer, and it is not as flexible as the semi-trailer when loading and unloading in the relatively narrow logistics center and freight yard, so this leads to the majority of truck users do not seem to buy the central axle trailer.
In fact, the length mentioned above is also the advantage of the axle trailer, and in some specific industries, the axle truck has more advantages. The first is the express delivery industry. Express light weight, large volume, need a larger amount of carriages, then than the ordinary semi-trailer 3 meters longer advantage is reflected, and most of the express logistics storage station space is relatively large, even this kind of long car, in and out and U-turn is very convenient.
The second is the equipment transportation industry. In Europe, you can see some flatbed car center axle trailers, front and rear sub-assembly equipment, machinery, loading and unloading is also convenient, the key is that the total length is longer than the traditional 17 meters, more suitable for loading slightly larger goods.
The third is the car transportation industry. Now the mid-axle vehicle in the car transportation industry has been very popular, the main reason is that this type of car is very suitable for the industry. With a total length of 22 meters, the upper and lower floors can hold a total of 8-9 cars, which is more cost-effective and more profitable than a semi-trailer that can only load 6-7 cars. The central axle trailer has been implemented for 8 years, but it has not been popularized in a large area, the main reason is that it is not suitable for the current logistics and transportation environment in China, and the purchase cost is higher than that of the semi-trailer, so of course, the semi-trailer is more favored by cardholders. However, the author believes that due to the distinctive characteristics of the central axle trailer, after the continuous improvement of the road conditions in the mainland and the continuous upgrading of the conditions of the freight yard, the future of the central axle trailer still has a lot of market space!
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撰文 | 小青编辑 | 向文谦
Design | Xiang Wenqian
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