Knowledge of hydraulic system principle of hydraulic lifts
With the lift aerial work, the lifting actuator are used hydraulic drive, the system is generally high pressure system, connected to the reliability of the executive components of high pressure hose, directly related to the normal work and efficiency of the institution, once broken, will endanger the safety of personnel and machinery.
Usually the reasons for the breakage of high-pressure hoses mainly include.
① machine operation, hydraulic cylinder movement with the lift, high pressure hose repeated flexing action, and thus fatigue breakage.
②Lift load changes, the hydraulic system will produce hydraulic pulsation, pulsation pressure reaches a certain value, the high pressure hose will break.
③ high pressure hose due to poor quality, hose and metal joint buckling connection strength is not enough, when the peak pressure in the hydraulic system, the pulling phenomenon. Most of the equipment at home and abroad are similar to the hydraulic principle, in the hydraulic cylinder and electromagnetic reversing valve between the general have a hydraulic control check valve to play a locking role, the difference is the location of the hydraulic control check valve, some are placed superimposed with the electromagnetic reversing valve, some placed on the hydraulic cylinder, lift the liquid cylinder using a plunger cylinder, down rely on gravity to fall.
When the liquid-controlled check valve and reversing valve superimposed, operation in case of unexpected accidents, the hydraulic hose connected to the liquid cylinder broken, then the lift lost support, in the load and self weight under the role of rapid decline, the huge inertia will cause a major accident caused by machine destruction. When the hydraulic control check valve is placed on the hydraulic cylinder, construction work such as hydraulic hose break, when the lift loses power, the hydraulic control check valve works, the equipment stays in mid-air can not lift, while a large amount of hydraulic oil sprayed (especially like the aircraft food truck is operating in the compartment, can not observe the situation below), a lot of manpower is needed to repair the fault. There are also used in the liquid cylinder plus speed limit cut-off valve, where its role is similar to the liquid cylinder plus liquid control check valve.
Therefore, we use hydraulic double pipeline explosion-proof safety valve, the hydraulic safety valve of the working oil pipe using hydraulic double pipeline, when a hydraulic oil pipe broken, a spool of the hydraulic safety valve will immediately close the pipeline, so that the air operation mechanism safety to maintain in place, while the other spool of the hydraulic safety valve work, immediately another hydraulic oil pipe automatically connected, the agency still maintain normal work to ensure the safety of the machine and personal.