How to maintain the pressure of the vacuum hot press system as an emergency power supply

How to maintain the pressure of the vacuum hot press system as an emergency power supply
The vacuum hot press maintains the system pressure as an emergency power source. When the hydraulic pump stops unloading, it supplies oil to the actuator. By releasing the oil pressure, it compensates for the leakage of the system oil accumulator and maintains the system pressure; The oil accumulator can also be used as an emergency hydraulic source to realize the safety of the hydraulic system. The hot press manufacturer opens the protective door in manual mode, puts the mold and the pressed material into the machine, and then clicks MANUAL to enter the manual mode. Vacuum hot press is a kind of electrical and mechanical connection device that heats two parts coated with soldering flux in advance to a temperature sufficient to melt and flow soldering tin. After solidification, an electrical and mechanical connection device is formed between the parts and soldering tin. The servo hot press has various working modes such as single working platform, rotary working platform, left and right mobile platform. Keep the system pressure for a period of time if! The power supply, interruption or failure of the prime mover and hydraulic pump depends on the liquid oil landing on the accumulator to reset the actuator, so as to avoid the accident caused by the damage of the whole machine or some parts and keep the system in a safe state. In order to use the pressure retaining circuit of the accumulator,
In the vacuum hot press, when the electromagnet lYA is energized, the three-position four-way solenoid reversing valve 5 is switched to the left position, and the hydraulic cylinder moves to the right. When the cylinder moves to the end, hydraulic pump 1 supplies oil to accumulator 4. When the oil supply pressure rises to the set value of the buckle relay, the pressure relay sends a message to energize the electromagnet 3YA, the two-position two-way solenoid reversing valve 7 switches up and down, and the hydraulic pump is unloaded by the overflow valve. At this time, the hydraulic cylinder maintains pressure through the accumulator. When the pressure of the hydraulic cylinder drops to a steep value due to leakage, the action of the pressure relay cuts off the power supply of 3YA, and the hydraulic pump supplies pressure oil to the system again. As the circuit of emergency power source in the hydraulic system of shipboard LNG unloading arm, nitrogen cylinder group (3) is added to the piston accumulator to increase the effective capacity. When the system works normally, the solenoid valve is cut off at the right position as shown in the figure, and the leakage hydraulic control check valve is closed. I The hydraulic source supplies energy to the system through the common check valve and leaks out. When the hydraulic source cannot supply oil to the system normally due to a sudden failure of the system, the electromagnetic power is switched to the left position, and the control pressure oil provided by the piston accumulator is reversely connected to the leakage hydraulic control check valve, which supplies oil to the system L and resets the unloading arm driven by the hydraulic cylinder.