What is the working principle of the hydraulic system of the truck tailboard and what are the common fault points?

The hydraulic system of the truck tail plate is the core component for realizing the function of cargo loading and unloading. Understanding its working principle and common fault points is crucial for ensuring the efficient operation of the truck tail plate and the safe loading and unloading of goods.

working principle

The hydraulic system of the truck tailboard mainly consists of components such as oil tank, oil pump, hydraulic valve, oil cylinder, and connecting pipelines. When the operation switch of the truck tailboard is activated, the oil pump starts working. The oil pump sucks hydraulic oil from the oil tank and converts mechanical energy into pressure energy of the hydraulic oil through mechanical action, causing the hydraulic oil to output at a certain pressure.

High pressure hydraulic oil is transmitted through pipelines to various hydraulic valves. These hydraulic valves play a crucial role in controlling the flow direction, pressure, and flow rate of hydraulic oil. For example, a directional valve can change the flow direction of hydraulic oil, thereby achieving the up, down, and stop actions of the tailgate. When the tail plate needs to rise, the directional valve switches the oil circuit to allow hydraulic oil to enter the rodless chamber of the cylinder, pushing the piston to drive the tail plate up; When the tailboard needs to descend, the directional valve changes the oil circuit, and hydraulic oil flows back to the oil tank from the rodless chamber of the cylinder. Under the weight and load of the tailboard itself, the tailboard descends. At the same time, the overflow valve can set the maximum pressure of the system. When the system pressure exceeds the set value, the overflow valve opens and returns excess hydraulic oil to the oil tank to protect system components from damage caused by excessive pressure.

After the hydraulic oil enters the cylinder, it pushes the piston to move in a straight line. The movement of the piston is transmitted to the tail plate through mechanical structures such as connecting rods, achieving the lifting and lowering action of the tail plate.

Common fault points

Hydraulic oil leakage: This is a common fault. Aging, damage, or improper installation of seals can cause hydraulic oil to leak from parts such as cylinders and pipeline joints. Hydraulic oil leakage not only causes a decrease in system pressure, affecting the normal operation of the tailboard, but may also pollute the environment.

Insufficient system pressure: Wear of the oil pump and damage to internal components can lead to insufficient output flow and pressure of the oil pump. In addition, hydraulic valve failures, such as stuck valve cores and poor sealing, can also cause the system pressure to fail to meet normal operating requirements, resulting in the tail plate not being able to lift normally or the lifting speed being slow.

Oil cylinder failure: The piston seal inside the oil cylinder is damaged, which can cause internal leakage of the oil cylinder and result in automatic lowering of the tail plate. In addition, bending and deformation of the oil cylinder piston rod can cause jamming and shaking during the lifting process of the tailboard.

Hydraulic oil pollution: Impurities, moisture, and other pollutants mixed in hydraulic oil can accelerate the wear of hydraulic components, causing faults such as valve core jamming and blockage, and affecting the normal operation of the system.

Understanding the working principle and common fault points of the hydraulic system of the truck tail plate can help operators and maintenance personnel discover and solve problems in a timely manner, ensuring the safe and stable operation of the truck tail plate.