Working principle of hydraulic punch

The fast descending electromagnets 1YA and 3YA are energized to switch the reversing valves 9 and 5 to the left and right positions, and the hydraulic pump 1 changes from unloading to oil supply. The pressure oil of the pump enters the small cavity C of the hydraulic cylinder through valves 3 and 5, part of the oil in cavity A is injected into cavity B through valve 6, and the surplus oil also enters the cavity C of the hydraulic cylinder. At this time, because the three cavities A, B and C are interconnected to form a differential connection, the piston (rod) drives the slider to descend quickly. Punching electromagnet 1YA. 2YA .3YA are all energized to switch the directional valves 9, 4 and 5 to the left, right and right positions, respectively. After passing through the check valve 3, the pressure oil of the hydraulic pump L is divided into two paths, one path enters the C cavity of the oil cylinder through the valve 5, the other path enters the B cavity of the oil cylinder through the valve 4 and the check valve 7, and the oil in the A cavity is discharged back to the oil tank through the valve 4. At this time, the acting area of the pressure oil is the sum of the areas of the B cavity and the C cavity, so the piston (rod) drives the slider to slowly descend with a large thrust to realize punching and shearing processing. The solenoid 3YA rises rapidly, and the solenoid 1YA and solenoid 2YA are de-energized, so that the directional control valve 9 is still in the left position, and at the same time, the directional control valves 4 and 5 return to the left position. The pressure oil of the hydraulic pump L enters the A cavity of the hydraulic cylinder through the valves 3 and 4, and at the same time, the cartridge valve 6 is opened. The return oil from chamber B merges with the pressure oil of the pump through valve 6 and enters chamber A together, while chamber C discharges the oil to the oil tank through valve 5. At this time, because the A cavity and the B cavity of the hydraulic cylinder are in differential communication, the piston (rod) drives the slider to rise rapidly.