Applicable places for hydraulic lifts

For high-altitude operations with lifts, the lifting actuators are driven by hydraulics. The system is generally a medium-high pressure system. The reliability of the high-pressure hose connecting the actuator is directly related to the normal operation and efficiency of the mechanism. Once broken, it will endanger the safety of personnel and machinery. Safety. Usually the main reasons for the breakage of high-pressure hoses include:
① When the machine is operating, the hydraulic cylinder moves with the lift, and the high-pressure hose repeatedly flexes, causing fatigue breakage; ② The load of the lift changes greatly, and hydraulic pulsation will occur in the hydraulic system. When the pulsation pressure reaches a certain value, the high-pressure hose will produce Breakage: ③ Due to poor quality of the high-pressure hose, the crimp connection between the hose and the metal joint is not strong enough. When the peak pressure occurs in the hydraulic system, extubation occurs.
Now take the aircraft food truck scissor lift as an example. At present, most equipment at home and abroad use similar hydraulic principles, between the hydraulic cylinder and the electromagnetic reversing valve. Generally, there is a hydraulic control check valve for locking. The difference is the position of the hydraulic control check valve. Some are stacked with the electromagnetic reversing valve, and some are placed on the hydraulic cylinder. The lifting cylinder uses a plunger cylinder. , it relies on gravity when descending.
When the hydraulic control check valve and the reversing valve are placed on top of each other, in case of an unexpected accident during operation, the hydraulic hose connected to the hydraulic cylinder is broken. At this time, the elevator loses its supporting force and drops rapidly under the action of load and self-weight. The huge inertia will A major accident resulting in aircraft crash and fatalities.
When the hydraulic control check valve is placed on the hydraulic cylinder, if the hydraulic hose is broken during construction operations, the elevator loses power and the hydraulic control check valve works. The equipment stays in mid-air and cannot be raised or lowered, and a large amount of hydraulic oil is sprayed out ( Especially like airplane food carts, which are operated inside the cabin and cannot observe the following conditions), a lot of manpower is needed to repair the fault. There is also a method of adding a speed-limiting cut-off valve to the liquid cylinder, where its function is similar to adding a hydraulic control check valve to the liquid cylinder.
Therefore, we use a hydraulic dual-pipeline explosion-proof safety valve L4-1. The working oil pipe of the hydraulic safety valve adopts a hydraulic dual-pipeline. When a hydraulic oil pipe is broken, a spool of the hydraulic safety valve immediately closes the pipe, causing the The aerial working mechanism remains safely in place, and at the same time, the other spool of the hydraulic safety valve works, immediately automatically connecting the other hydraulic oil pipe, and the mechanism still maintains normal operation, ensuring the safety of the machine and people.