The hydraulic press is composed of the main engine and the control mechanism. The main engine of the hydraulic press includes the main body, the main cylinder, the ejection cylinder and the filling device. The power mechanism is composed of oil tank, high-pressure pump, low-pressure control system, motor, various pressure valves and directional valves. Under the control of electrical device, the power mechanism realizes energy conversion, regulation and transmission through pumps, oil cylinders and various hydraulic valves to complete the cycle of various process actions.

Oil presses are classified according to structure

It is mainly divided into four column hydraulic press, single column (C-type) hydraulic press, horizontal hydraulic press, vertical frame hydraulic press, etc.

Classification according to the use of hydraulic press

It is mainly divided into metal forming oil press, bending oil press, stretching oil press, blanking oil press, powder (metal, non-metal) forming oil press, press mounting oil press, extrusion oil press, etc.

Basic knowledge of hydraulic press

1. Power: flow × Pressure (p × q) 　　

a. Flow: nominal tonnage ÷ 250=piston area × Speed=flow

b. Pressure: 250kgfcm2=25mpa

c. Power: nominal tonnage × 1000kg/t × 9.8n/kgf × 250kgf/cm2 × Speed/m3250kgf/cm2 motor power n=power ÷ efficiency (efficiency is generally taken as 90%), 9.8 is gravity acceleration 1kgf=9.8n. Generally, it is calculated according to the above formula, but for special cases, such as glass fiber reinforced plastic products hydraulic press, we should compare the flow speed and pressure to take the larger value. The FRP hydraulic press has a preloading action, which requires a higher speed and a slightly lower pressure. In actual calculation, the power required for this action is the largest. Therefore, under special circumstances, it should be noted that the power of the auxiliary system should be taken into account in this matter. Long term work should be included. Short term work, such as mobile workbench, can be ignored. 　　

2. For the size of oil pump required, we should calculate the flow of oil pump at each stage. For example, 32 series four column hydraulic press generally uses ycy series constant power oil pump. When working under high pressure, the flow is: nominal tonnage ÷ 250kgf/cm2=piston area, piston area x speed=flow. Since ycy series oil pump takes 50% - 80% of the rated flow when working under high pressure, the required oil pump should be: flow ÷ the set output value, It should also be noted that the nominal flow of the pump is the displacement per revolution. Generally, the four pole motor is 1450 rpm, and the six pole motor is 960 rpm, so the displacement per minute is, and the nominal displacement of the pump is 1450 rpm × (or 960)

3. The valve model shall be selected according to the flow and pressure through the valve

Operating system

1. The personnel of the hydraulic press shall have corresponding qualifications and must work with certificates. It is strictly prohibited for those who do not know about the machine to start and use the hydraulic press. 　

2. Wear the specified labor protection articles before work. Oil press

3. Before starting, check the following items: whether the photoelectric protection device is reliable, whether the travel switches are sensitive, and whether the fasteners are loose. 　　

4. Clear the sundries on the working table and the mold, adjust the working pressure and the stroke of the sliding block, and run the empty car for one to two minutes. Only when everything is normal can it work. 　　

5. The adjustment handle on the machine has been adjusted properly when leaving the factory, and can not be adjusted at will by non commissioning personnel

Maintenance system

1. Lubricate and maintain according to the lubrication requirements of the machine. 　　

2. After each year of operation of the machine tool, the hydraulic oil shall be drained from the machine body oil tank for cleaning, and the filtered hydraulic oil shall be refilled. The oil volume shall be determined at 3/4 of the height of the oil pointer. 　　

3. The oil filter screen on the oil suction pipe must be cleaned or washed regularly. 　　

4. Regularly check whether the handle, knob and key are damaged. 　　

5. The motor must be kept clean, and the air inlet grille of the motor must always be kept in a good ventilation state, without blocking. 　　

6. Oil, lubricate and clean the machine tool 10 minutes before work every day. 　　

7. Non operators are strictly prohibited to operate the equipment, and people must leave the machine and stop at ordinary times.