New Injector Nozzle Dlla150pn315 for Mitsubishi Engine

The paired grinding process is adopted for the needle valve parts, and the surface roughness is .025μm. The pairing clearance of the needle valve coupler is very small, generally 1~4μm. In the actual operation of the needle valve couple, due to the high pressure of the fuel, as well as the relative movement and deformation between the couple, fluid lubrication between the couple is formed. According to the theory of lubrication analysis, the viscosity of fuel oil has a great influence on the lubricating characteristics of fuel oil, and when the working conditions are constant, the viscosity of lubricating oil determines the thickness of lubricating oil film. According to the theory of tribology, the lubrication of the needle valve coupling is boundary lubrication. In boundary lubrication, due to the unevenness of the mating surface, the oil film between the contact peaks bears a part of the load, so the viscosity of the fuel has a significant impact on the lubrication and load-carrying capacity of the needle valve assembly.

The needle valve coupling adopts the diesel self-lubricating method, and the oil film is formed in the mating gap of the needle valve coupling by utilizing the leakage flow of high-pressure diesel oil, avoiding the direct contact of the sealing surface of the oil film. The content of wear-resistant substances in diesel oil determines the lubricating ability of diesel oil. There are natural lubricants in diesel oil, such as sulfides and polycyclic aromatic hydrocarbons. Due to the harsh hydrogenation process and the commonly used desulfurization treatment in the diesel production process, the content of wear-resistant polar compounds is very low, and the content of polycyclic and bicyclic aromatic hydrocarbons is also small, so the self-lubricating ability of diesel oil is generally relatively low. Difference.