Hydraulic system is the blood of modern continuous production line, and its importance is self-evident. When the system runs for a period of time will inevitably occur oil pollution, it is understood that more than 90% of the failure of the hydraulic pneumatic system in the industry is caused by pollution, such as hydraulic cylinder block scratch leakage, cylinder block operation pressure fluctuations, valve oil circuit blockage, actuator plug, hydraulic component loss acceleration (filter, pump). So how to effectively deal with the production of pollution is the key factor to ensure the normal operation of the hydraulic system. Custom cylinder
Hydraulic oil pollutant composition is mainly composed of hydraulic cylinder wear metal debris, seal debris, water and dust particles, the source of pollution in the seal, there are three reasons.
1. Failure of hydraulic cylinder seal.
At present, the seals commonly used in domestic hydraulic cylinders are traditional nitrile butadiene rubber (NBR) or polyurethane polyurethane (PU) standard Yx ring as a seal ring, and the main problems in use are: ① material hydrolysis failure, such as polyester polyurethane commonly used in hydraulic cylinders. ② Seal wear failure. When the hydraulic cylinder is worn, the water and dust in the air will enter the hydraulic cylinder through the dustproof ring that has been worn, and this is often not cause for concern.
On-site maintenance personnel often do not pay much attention to the wear of hydraulic cylinder seals, slight wear will not cause too much attention, even if the replacement will only replace some of the seals, and ignore the overall change, the overall seal of the hydraulic cylinder is no longer suitable for the original hydraulic cylinder seal groove. Each part of the seal of a hydraulic cylinder is very important, they complement each other, interact with each other, and restrict each other, which is an organic whole.
2. Seal failure of hydraulic pipe joint.
The sealing of pipe joint of hydraulic system mainly adopts O-ring and combined washer. The O-ring is mostly fluorine rubber O-ring, and the combined seal is mostly the combined seal of nitrile rubber and metal. However, the ordinary domestic fluorine rubber O ring has low dimensional accuracy, poor temperature resistance, pressure resistance and corrosion resistance, which is easy to occur in the installation and use process according to the installation damage, excessive extrusion deformation, chemical corrosion, thermal corrosion and other phenomena, and the generated debris will pollute the hydraulic oil into the hydraulic system. Combined gasket using mold processing, low dimensional accuracy, rough surface, poor pressure performance, under the local high pressure load, easy to failure and collapse, loss of a lot of hydraulic oil, the debris will also pollute the hydraulic system.
3. Secondary pollution occurs during maintenance.
In the field maintenance process, the maintenance personnel do not pay attention to the cleaning of the site, and bring dust into the system when replacing the oil pipe, valve and hydraulic cylinder, so that pollutants have more opportunities to enter the system.
Therefore, improving the variable sealing parts, using a more reasonable sealing material, improving the sealing accuracy, changing the variable sealing structure, not only solves the leakage problem, but also prevents the entry of pollutants.
Aiming at the pollution control problem of the hydraulic system, the hydraulic cylinder seal and pipeline seal of the system were surveyed and analyzed, the complete set of hydraulic system seal was improved, and the hydraulic system of the cold rolling mill was upgraded with internationally advanced sealing materials and processing technology, including the cylinder seal of the important hydraulic cylinder and the seal of the pipeline were all customized according to the specific conditions of the equipment.
1. Hydraulic cylinder seal upgrade.
① Material upgrade.
Polyether polyesters with low friction coefficient were used to replace traditional polyester polyesters. The seal is a wearing part in the hydraulic cylinder, and its own friction coefficient, anti-wear, anti-hydrolysis, anti-aging, anti-extrusion and other properties determine its sealing effect, environmental adaptability and the amount of debris generated by the wear and tear of the cylinder block, which is closely related to the service cycle of the seal.
② Accurate control of size, reasonable adjustment of interference.
At present, the domestic sealing ring almost all adopt the method of mold processing, and the hydraulic cylinder continues to appear in various degrees of wear in the movement, affecting the service life of the cylinder.
The international advanced turning process is widely used in the production of rubber seals used in maintenance, for the wear of hydraulic cylinders, tailored, can achieve a high guarantee of sealing dimensional accuracy requirements.
2. Upgrade the connector seal.
① O-ring upgrade.
The use of imported DuPont VITON fluorine rubber material, the application of turning technology processing O-ring, to solve the material anti-aging, anti-extrusion, anti-corrosion ability, poor processing accuracy, improve the service life of O-ring, reduce fuel consumption.
② Combination gasket upgrade.
The combination gasket of polyether polyamine ester 2Cr13 has a bearing capacity of up to 100MPa, which solves the problem of rough processing and pressure difference resistance of the original gasket.
In addition to the above leak prevention and control measures, it is necessary to strengthen the daily maintenance and management work, implement the short-cycle plan and spot inspection system, and ensure the quality and quantity of each repair year. The maintenance and operation personnel have been trained and theoretical learning. In this way, the pollution source control of the hydraulic system will certainly achieve good results, reduce the loss of hydraulic oil and reduce the production cost.
