What are the internal and external factors of oil seal aging of Tianjin FAW small valve?

Valve seal is a kind of oil seal, which is generally vulcanized by outer frame and fluororubber. The radial opening of the oil seal is equipped with a self-tightening spring or steel wire for sealing the valve guide rod of the engine. Valve oil seal can prevent engine oil from entering the intake and exhaust pipes, avoid engine oil loss, prevent the mixture of gasoline and air and waste gas from leaking, and prevent engine oil from entering the combustion chamber. Valve oil seal is one of the important parts of engine valve group, which is in contact with gasoline and engine oil at high temperature, so it is necessary to use materials with excellent heat resistance and oil resistance, generally made of fluororubber. Reasons for the aging of the valve oil seal: First, the installation of the valve oil seal: if it is mixed during installation, or foreign matter and dust in the pipeline enter the seal and cause leakage; Poor assembly leads to seal damage and leakage; The wrong installation direction of the seal causes leakage, or the coating treatment is uneven, and the coating enters the sealing layer. Secondly, the choice of seal: the gap caused by high pressure bites, and then mixed with air, adiabatic compression causes seal combustion; High-frequency reciprocating motion leads to heating and dry grinding of seals; Environmental dust causes abnormal wear of sealing ring; Rusting of sealing groove leads to leakage, etc. Third, the design of sealing equipment. These include: 1, improper material selection of guide support, and damage of cylinder and piston rod. 2. Improper clearance of friction pair will lead to extrusion and occlusion. 3. Improper thread guide angle at the end of cylinder barrel piston cylinder will damage the sealing ring. 4. Improper installation guide angle of the seal will damage the sealing ring. 5, the sliding surface roughness is not appropriate, wear sealing ring. 6. The electroplating is uneven, the surface through which the seal passes has an opening, and the sealing ring has scratches and wear. 7. Damage the seal. Finally, it may be the product itself, or the problem of sealed storage. Exposure to high temperature during transportation leads to deterioration and deterioration of sealing materials.