Tank trucks are transport vehicles with tank-shaped bodies, used to transport various liquids, liquefied gases and powdered goods, including gasoline, crude oil, various viscous oils, vegetable oils, liquid ammonia, alcohol, water, various acid and alkali liquids, cement lead oxide powder, etc. Tank trucks occupy a very important position in transportation, accounting for about 18% of the total number of trucks.
Classification
Tank trucks can be divided into two categories according to the mode of transportation: railway tank trucks and road tank trucks.
Road tank trucks can be divided into oil tank trucks, gas tank trucks, liquid tank trucks, powder tank trucks, cement mixing tank trucks, refueling tank trucks, etc. according to their uses.
Structure
Although there are many types of tank trucks, they are all integral load-bearing structures. Most tank truck bodies are composed of two major components: the tank body and the chassis.
Tank body
The tank body of the tank truck is a horizontal cylinder structure, and its cylinder part is welded by the upper plate, the bottom plate and the end plate. The upper plate is made of 9mm thick steel plate rolled into a road tank type. Due to the large force on the bottom plate, a 11mm thick steel plate is used. The bottom plate accounts for about 1/4 of the circumference of the entire cylinder. The end plate is 11mm thick and the steel plate is hot pressed into a spherical convex panel with a transition arc part.
Generally, the spherical radius of the end plate of a tank truck is about 3500mm, and the transition radius is 100mm. When the cylinder plate of the tank body is made of ordinary low-alloy steel, the thickness of the steel plate is 8mm and 10mm. The diameter of the tank body increases with the increase of volume. The inner diameter of a tank with a volume of 30 cubic meters is 2100 mm; the inner diameter of a tank with a volume of 50 cubic meters is 2600 mm; the inner diameter of a tank with a volume of 60 cubic meters is 2800 mm.
However, due to the existence of the air bag, the manufacturing process is more complicated and it is not convenient to clean the tank body. In addition, practice has proved that when the liquid is not full, the impact on the end plate of the tank body is not so significant, so the tank trucks currently produced have cancelled the air bag. In order to ensure that the total volume of the tank body remains unchanged, the length of the tank body is lengthened to make up for the volume of the air bag. At this time, there is a ruler in the tank body to limit the oil load, leaving empty volume for liquid expansion to avoid overflow when the liquid expands.
Tank car chassis
Since the tank body itself has great rigidity, the weight of the liquid in the tank is mainly borne by the tank body, and then transmitted to the steering tank car frame through the bracket and the bolster, so the tank car chassis mainly bears the horizontal longitudinal traction impact force. The middle beam is generally made of two channel steels, and the central part is covered with an 8 mm thick upper cover plate, on which the tank body lower saddle plate is welded, and the center of the cover plate is provided with an oil collection hole or an oil drain valve hole, and there are drainage pipe holes at both ends (when there is a heating sleeve), and the middle beam is welded with a reinforcement lower cover plate near the center plate. The bolster generally adopts a box-shaped section, on which the tank body bracket is installed, which is composed of a webbed plate and a pad. The webbed plate is riveted or welded to the steel plate of the bolster and molded and welded into a groove shape. The end beam and the bolster are supported on it by the pad. The end beam is molded and welded into a groove shape by a 6 mm thick steel plate. There is a side beam between the end beam and the bolster, which is mainly used to enhance the end rigidity and transfer part of the longitudinal force to the bolster. In addition, the chassis is also equipped with railings, walkways, handrails, pedals, etc.
Tank car without chassis
Since the tank body of the tank car is an integral cylindrical structure with greater strength and rigidity, the tank body can not only bear the weight of the liquid contained, but also the longitudinal force acting on the tank car, and the chassis can be omitted. The tank car without chassis has no middle beam, side beam and cross beam between the two bolsters. The tank body is welded with the traction beam and the bolster, and the connection device between the tank body and the chassis is cancelled. There is no need for a card belt, which can reduce the dead weight of the tank car and give full play to the bearing function of the metal material of the tank body. The difference between the tank body of the tank car without chassis and the tank body of the tank car with chassis is the support part at both ends. The traction beam and bolster of the tank car without chassis are connected to the tank body by welding to transmit the longitudinal force.