The vertical hydraulic pump station is equipped with an accumulator for air cooling. Domestic dump trucks can be used for parking and driving power take-off, but the operating instructions for rear dump trucks strictly prohibit driving power take-off and hydraulic cylinder lifting. The above accident was caused by the driver's misoperation of the pneumatic valve while taking power while driving.
After parking, lifting, and unloading the cargo, the driver did not turn off the power take-off switch in a timely manner. Instead, he only dropped the cargo box and turned the lifting control valve to the "medium stop" or "neutral" position. It seemed that the cargo box had fallen into place and the operation was safe to run, but in fact, during this process, the driver forgot the most critical operation link - turning off the power take-off switch to stop the hydraulic oil pump from working. The operation of the oil pump means that the hydraulic system has a power source. In this case, a misoperation on the pneumatic valve directly resulted in the automatic lifting of the cargo box.
If the driver fails to detect the operational error in a timely manner, due to the high speed of the vehicle and the high speed of the hydraulic oil pump, the hydraulic cylinder can be quickly lifted, and the lifting time is only a few seconds. This is what witnesses call "cargo box bouncing up". If there happens to be a bridge on the road section, it will cause a major accident.
Most of the accident vehicles are T-type dump trucks (as shown in Figure 2), which are belly lifted dump trucks. The hydraulic cylinder stroke of the T-type dump truck is generally less than 1m, and the cargo box is lifted by a lifting amplification mechanism. If the above erroneous operation occurs, the automatic "lifting" speed of the cargo box is faster than that of the front top dump truck; The front top dump truck shown in Figure 3 generally has a larger hydraulic cylinder stroke. The commonly used stroke range of the front hydraulic cylinder on the market is from 3 cylinders (stroke 3800mm) to 5 cylinders (stroke 6180mm), so the so-called "cargo box bouncing" situation of the front dump truck will not occur. Vertical hydraulic pump station equipped with accumulator air cooling