Filling valves are used in medium and large hydraulic presses. The purpose is to increase the oil supply and make the piston of the master cylinder descend quickly. Installed between the upper tank and the main cylinder. Its working principle: when the piston of the master cylinder is lowered, the piston is lowered due to its own weight, causing the upper cavity of the master cylinder to be in a vacuum condition. The valve port of the oil filling valve is sucked open, and the oil in the upper oil tank is put into the upper cavity of the master cylinder. After the piston is in place, the tension spring closes the filling valve, and the compressor operates under the pressure of the oil pump. Then the piston reverse-travel oil pump is required to supply oil to the lower chamber of the master cylinder. When the piston is not moving, the lower chamber has pressure. The small tube turns this valve over to open the charge valve. When the piston rises, the oil returns to the upper tank. After the upper fuel tank is full, there is a large pipe to return more to the lower fuel tank.

The charging valve is usually used as a suction and discharge valve between the hydraulic cylinder and the oil tank. The rapid progress of the charging valve large press must suck oil from the oil cylinder to the oil tank, and avoid flowing from the oil cylinder into the oil tank when pressurizing, and discharge oil from the oil cylinder when reverse. To the fuel tank. Flange-type liquid filling valve has small volume, large flow rate and no leakage. It can be directly welded or flanged to solid. The large flow rate is the value obtained when the pressure is lost during free movement. The low hydraulic control pressure ratio is determined by the area ratio of the valve seat and the hydraulic control pressure. When returning, the pressure must be released first, otherwise it will not be able to open or cause an impact. When the cylinder it controls is forced to travel, the control oil is pressure oil, and the filling valve is opened. The filling valve cavity of the cylinder draws a lot of oil due to vacuum. When pressure is required to continue moving, the control pressure oil is disconnected and the filling valve is closed. , The filling valve cavity of the oil cylinder runs slowly with high pressure oil. When returning, the filling valve opens again, and the oil quickly returns to the tank through the filling valve.

The filling valve adopts a spring-loaded disc cut-off structure, which enables the piston to be quickly filled and discharged under pressure. The filling valve can also be set with a pre-opening pressure, which has reliable sealing performance. Excellent processing, high precision, no leakage, good pressure holding performance. With its own slow-moving spool, it can effectively reduce noise and vibration.

The filling valve is used in the medium and these compressors with more than 100 tons. The oil cylinder is relatively large. It only depends on the oil supply and the downward speed is too slow. Therefore, an upper oil tank is set on the top of the compressor, between the upper oil tank and the upper cavity of the oil cylinder. Device filling valve. When the piston is lowered, the filling valve is opened, and the oil in the upper tank is directly filled into the upper cavity of the cylinder. When pressurizing, pressurize by oil pump. When the piston rises, the filling valve opens, and the oil in the upper cavity of the cylinder returns to the upper tank. The traditional charging valve is usually used as an indirect oil suction and discharge valve. In the fast process of a large press, oil must be sucked from the oil tank of the cylinder to prevent the cylinder from flowing into the oil tank when it is pressurized, and from the cylinder to the oil tank when it is reversed. The traditional filling valve has exquisite machining, high precision and outstanding pressure holding function. The traditional filling valve has a cushion valve core, which can effectively reduce shock and vibration. Traditional liquid filling valves are widely used in high-speed punches, presses, injection molding machines and other machines.