New Injector Nozzle Dlla146p2324 0433172324 for 0445110 Injectors

As the fuel pressure increases, the leakage rate of the oil film in the gap between the needle valve coupling parts increases. The change rate of leakage rate corresponding to one-way fluid-solid coupling remains unchanged, while the leakage rate corresponding to thermal-fluid-solid coupling calculation and static test has little difference with pressure test, thermal-fluid-solid coupling, and one-way fluid-solid coupling. When the fuel pressure increases, the temperature of the oil film in the gap increases, and the elastic deformation and thermal deformation increase. The difference between the coupling calculation results and the test results is becoming more and more obvious. Therefore, the thermal deformation of the needle valve assembly caused by the temperature rise of the fuel oil cannot be ignored when designing the needle valve assembly of the fuel injector. The material selection of the needle valve assembly, the needle Enhanced heat transfer of the valve coupler, deformation compensation of the needle valve coupler, etc. to reduce the rate of change of leakage rise caused by the thermal deformation of the needle valve coupler gradually increases, that is, the sealing characteristics of the needle valve coupler accelerates to deteriorate. When the fuel pressure is low, there is little difference between heat-fluid-solid coupling and unidirectional fluid-solid coupling. This is because the elastic deformation of the needle valve coupling is small at low pressure, and the temperature of the oil film in the gap is low, so the thermal deformation of the needle valve coupling is small. When the fuel pressure rises, the temperature of the oil film in the gap rises, and the elastic deformation and thermal deformation increase. The difference between the coupling calculation results and the test results is more and more obvious. Therefore, the thermal deformation of the needle valve assembly caused by the temperature rise of the fuel oil cannot be ignored when designing the needle valve assembly of the fuel injector. The material selection of the needle valve assembly, the needle The enhanced heat transfer of the valve couple, the deformation compensation of the needle valve couple, etc. reduce the leakage caused by the thermal deformation of the needle valve couple. At high pressure, the elastic deformation and thermal deformation of the needle valve coupling cannot be ignored.