Commissioning of hydraulic loading test bench for

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Commissioning of hydraulic loading test-bed for large components

hydraulic synchronous lifting technology for large components is a new construction and installation technology. It adopts the new principles of flexible steel hinged wire or rigid column load-bearing,

elevator cluster, computer control, and hydraulic synchronous lifting, combined with modern construction methods, after assembling thousands of tons of components on the ground

surface, it is lifted to the predetermined height and installed in place as a whole. The installation process is simple, fast, safe and reliable. Therefore, a test-bed for hydraulic synchronous lifting system of large components is designed. The test-bed includes three parts: hydraulic synchronous test-bed, hydraulic loading test-bed and computer control system. This paper only describes the function and commissioning test of hydraulic loading test-bed. L the principle of hydraulic loading system and its computer control the function of hydraulic loading system is to provide load-bearing load for hydraulic synchronous lifting system to simulate the structural parts of actual lifting system. Two loading hydraulic cylinders a and B, the load of cylinder a is loaded to l # and 2 # hydraulic elevators through a hinged connector, and the load of cylinder B is loaded to 3 # and 4 # hydraulic elevators through a hinged connector. The principle of the hydraulic loading system is shown in Figure 1. It can be seen from Figure 1 that the outlet pressure oil of hydraulic pump 1 is shunted through diverter valve 3 and then enters the large chamber of two hydraulic loading cylinders 6 through electromagnetic directional valve 4 and overflows from the proportional overflow valve. During synchronous lifting, the oil loaded into the large chamber of the hydraulic cylinder and the medical equipment products have high requirements for the quality of raw materials. The oil from the manufacturing of the precision diverter valve is checked from the proportional overflow valve to see if the oil circuit system joint is tightened for overflow, so the synchronous lifting speed can be higher. During synchronous descent, part of the oil from the diverter valve enters the large chamber of the hydraulic cylinder, and the other part overflows from the proportional overflow valve. Therefore, the synchronous lowering speed cannot be too high, and the proportional speed regulating valve can only work at a lower working point, so as to prevent the steel hinge wire from being unloaded when the cylinder extension speed of the loading system is lower than the synchronous lowering speed. Since the population pressure of the proportional overflow valve is directly proportional to the input current, as long as a certain current is input, the corresponding pressure can be obtained, that is, the loading pressure of the system. The current signal is obtained through the pulse width modulation signal output by the computer. The one-way valve 9 is set to replenish oil to the small chamber of the loading hydraulic cylinder when the system rises synchronously. The slide valve of solenoid directional valve 4 is M-type, and the user can set it at will, so that the loading hydraulic cylinder can stay at any position

1. hydraulic pump 2. Safety valve 3. Diverter valve 4. electromagnetic directional valve 5. connector

6. loading hydraulic cylinder 7. Steel hinge line 8. Proportional overflow valve 9. One way room 10. the hydraulic pump of pressure sensor loading system is a manual variable piston pump, and the maximum flow is 36 L/min. The cylinder diameter of the loading hydraulic cylinder is 250 mm, the rod diameter is 180 mm, and the stroke is 1000 mm. 2 debugging when debugging the loading test bench of the hydraulic synchronous lifting system that has been built, the computer program should be compiled first, but the computer program should meet two requirements: (1) it can automatically control the start and stop of the hydraulic pump station; (2) Input a wide modulation signal to the two electro-hydraulic proportional relief valves, and then get the pressure of the hydraulic cylinder through the pressure gauge and pressure sensor. Change the size of the pulse width signal to get the corresponding pressure. The debugging process is divided into two stages: pulse width increasing and pulse width decreasing. Finally, the relationship between the obtained pulse width signal and pressure is drawn into a curve, as shown in Figure 2 (a) and (b). It can be seen from the figure that the hysteresis of the curve is very small. In this way, the size of the load can be easily known according to the input pulse width during the subsequent hydraulic synchronous lifting test. 3 conclusion the debugging test of hydraulic loading test-bed shows that it basically meets the requirements of simulating synchronous lifting load, and the design is successful. At present, it has been applied to the preliminary preparation and test stage of some key projects such as the Three Gorges Project

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