Double-action Press Machines Hydraulic working principle and output pressure and working speed
Double-action Press Machines Hydraulic is a press machine using hydraulic transmission technology, which can be used to complete various forging and pressure forming processes. For example, forging of steel, forming of metal structural parts, pressing of plastic products and rubber products, etc. Hydraulic press is one of the earliest machines to apply hydraulic transmission. At present, hydraulic transmission has become the main transmission form of pressure processing machinery. In heavy machinery manufacturing, aviation industry, plastics and non-ferrous metal processing industries, etc., hydraulic presses have become important equipment.
The hydraulic transmission system of the hydraulic press is mainly based on pressure conversion, with high system pressure, large flow and high power. Therefore, special attention should be paid to improving the power utilization rate of the prime mover and preventing shock and vibration during pressure relief to ensure safety and reliability.
According to the requirements of the pressing process, the main cylinder of the hydraulic press can complete the basic working cycle of rapid downward movement, deceleration and pressing, pressure holding delay, pressure relief return, and stop (any position), and the pressure, speed and pressure holding time need to be adjustable. The ejector hydraulic cylinder is mainly used to eject the workpiece, and it is required to realize the actions of ejection, retraction and stop. For example, when the sheet is stretched, auxiliary actions such as lifting, stopping and pressure return of the ejector hydraulic cylinder are required. Sometimes it is necessary to press the blank with a blank holder to prevent the periphery from wrinkling.
The hydraulic press takes the maximum pressure (tonnage) that may be output by the main actuator (master cylinder) in the main movement as the main specification of the hydraulic press, and has been serialized. The tonnage of the top cylinder is often 20% to 50% of the tonnage of the main cylinder. The ejector cylinder of the extruder can use about 10% of the main tonnage. The tonnage of the blank holder cylinder of the double-action stretching hydraulic press is generally about 60% of the tonnage of the stretching cylinder.
The speed of the master cylinder is determined by the needs of the pressure processing process. Generally, in the hydraulic system directly supplied by the pump, the working stroke speed does not exceed 50mm/s, the fast forward speed does not exceed 300mm/s, and the hydraulic press fast reverse speed and fast forward speed. speed is equal.