The frame is of space skeleton type low alloy steel welded structure.
It is welded by two I longeron and beam to support loading.
The frame of flatbed semi-trailer is of gooseneck type.
The king pin and its seat board are below the forepart of the frame. The king pin is to transmit tractive force or braking force.
It has two dimensions: 2 inch (∮50.8) and 3.5 inch (∮88.9); and it is of three types: welded type, assembling type and interconnection type.
The king pin seat board is to bear the weight from vertical direction.
The front close plate of the frame is installed with gas pipe connectors and seven core socket of electric circuit.
The front, rear and side parts of the frame is installed with various lighting equipment.
The front lower part of the longeron is welded with seat board for installing landing legs, and the rear lower part with front, middle and rear brackets to support steel plates.
The frame of the container semi-trailer is welded with turn lock according to the ISO standard to fix the container.
In order to keep the semi-trailer park stably after it is separated from the tractor, two left-right linkage or single-acting landing legs are equipped.
The legs are composed of lead-screw drive mechanism, bevel drive mechanism, double speed reduction box, drive rod, operating handle, etc..
When pushing the handle in, operate the legs at high speed; when pull it out, operate at low speed;
when the legs touch the ground, operate at low speed.