Low pressure filters can be used for mineral oils, lubrication oils, non-flam fluids,
synthetic and rapidly biodegradable fluids. pressure filter, oil filter, hydraulic filter, low pressrue filter Xinxiang Shengda Filtration Technique Co., Ltd. , https://www.shengdafiltration.com
In this case, if the cylinder is not pressurized, only the directional valve cannot hold pressure. There are three possibilities:
One is that the directional valve itself leaks. The oil at the upper end of the cylinder flows out. At this time, you can see the pressure gauge pointer slowly descending;
The second is the obstruction of the oil circuit from the foot switch to the reversing valve. Insufficient power to promote the directional valve, the valve core slowly "drift", open the tubing, spray some oil to try;
Third, there is air in the system entering the cylinder. Check the sound of the oil pump and the return of oil in the fuel tank.
The upper blade of the machine is up and down normally, and there is no problem at all. Only after the presser foot goes down, it will be lifted a little, there will be a gap between the pressed plates, and it will not be able to compress the cut plate. According to the China Machine Tool Network (Machine35.com), usually the presser foot is hydraulic power. The system should be pumped out of the oil. Through the directional valve, the upper end of the oil cylinder, the piston of the oil cylinder goes down, and the hydraulic oil at the lower end of the oil cylinder enters the nitrogen accumulator. . After the work is completed, the reversing valve is opened, the accumulator oil returns to the lower end of the cylinder, and the piston is pushed upward. The foot switch should directly control the opening of the reversing valve.