Analysis of Hydraulic Control System of Concrete Conveying Pump Automatic Commutation (Part Two)

This control mode circuit impact is small, the distribution of circuit shock by the control mode. The specific process is as follows: the four-way valve 4 of the main oil line is reversed by the orifice, the four-way valve 4 reverses and lags behind the four-way valve 5, the distribution hydraulic cylinder preferentially performs the switching action within a short time (0.2~0.3 s) Anti-concrete backflow; and the main hydraulic cylinder in the distribution of hydraulic cylinder before (0.03 ~ 0.05s) action, shunt the main pump fuel supply, so that the distribution valve in place to reduce the impact. The accumulator in the system can absorb the instantaneous peak impact in the main circuit, and the relief valve 7 can relieve the continuous impact. This control method reversing action is reliable, but the control circuit repair more complicated. Figure 3 shows the reverse flow control electronic control circuit diagram of liquid-level control. The principle and the control method shown in Figure 2 similar, but the manual valve 3 and 4 in Figure 2 to electronic control. This control loop is characterized by: automatic reversal of reliable, the main hydraulic cylinder in place after the allocation of action, the allocation of action in place, the main cylinder began to push. Commutation impact than Figure 1, Figure 2 shows the control method. However, the throttle valve 7 and the accumulator can well relieve the impact of the distribution oil passage. 3 Electro-hydraulic synergetic control Electro-hydraulic synergistic control of the more common cartridge valve with electro-hydraulic valve control. (1) Cartridge valve with electro-hydraulic commutation automatic reversal Figure 4 shows the cartridge valve with electro-hydraulic commutation control schematic diagram. After the main pump is operated, the valve 2 cuts off the main pump overflow, the solenoid valve 9 is in the left position, the valve 8 is in the left position and the cylinder F2 is in action; the right end of the solenoid valve 1 lags behind the solenoid valve 9 (0.15 ~ 0.2s). Control oil through port A of valve 1 to maintain pressure oil at port X of valve 4 and valve 6. A, B port closed, valve 3 and valve X port unloading oil, A, B port conduction, T1 cylinder retracted to the end, the collision stroke switch, so that the solenoid valve 9 in the right position, the valve 8 is in the right work , The cylinder F1 action in place; solenoid valve 1 lag behind the solenoid valve 9 (0.1 ~ 0.15s) have electricity. Control the right valve through the B port of the valve 3 and valve 5 X into the oil. Port A and B are closed, ports X and X of valve 4 and valve 5 are unloaded. Ports A and B are conducting, port T2 has oil in the rod chamber, and oil in the rod chamber of T1 has been pushed. (2) electro-hydraulic directional control valve automatically reversing Figure 5 shows the schematic diagram of the electro-hydraulic directional control valve. After the solenoid valve B of valve 1 is energized, the main pump overflows and cuts off. Valve 3 right work F1 cylinder rodless chamber into the oil action in place; valve 2 lag valve 3 (0.1s ~ 0.15s) right work, T1 rod chamber into the oil retraction, T2 push concrete. T1 retracts to the end collision limit switch. Valve 3 right work, F2 cylinder rodless chamber into the oil action in place. Valve 2 lag valve 3 (0.1s ~ 0.15s) left bit work, T2 rod cavity into the oil retraction, T1 push concrete, in turn cycle. 4 Conclusion The above control reverse conveying automatic control and reverse conveying the opposite. Figure 3 way is to use two four-way solenoid valve to achieve. Figure 1, 2 through the manual two-way valve to achieve the commutation. The reverse transport of Figures 4 and 5 is achieved through the logical transformation of the electrical system. Currently in electro-hydraulic synergetic control, are generally used programmable logic controller PLC, used to reduce the impact of the environment on the components.