In the long-term operation of the injector needle valve assembly, due to the combined action of the high-pressure oil erosion, the grinding of mechanical impurities, and the seating of the pressure spring, the mating surface of the needle valve and the valve body will be worn out, causing oil injection The phenomenon of oil leakage and oil dripping after the oil is cut off causes poor atomization, incomplete combustion, sharp increase of soot, and serious carbon deposits. Therefore, regular maintenance of the injector must be carried out.
When disassembling, remember the cylinder sequence of each injector, remove the injector from the cylinder head, perform a simple external cleaning, and then disassemble, inspect and assemble one by one to prevent the same parts of different injectors from being assembled. Blend with each other. The specific steps are: first clamp the nozzle hole of the fuel injector downward on the vise, remove the pressure regulating screw cap, pressure regulating screw and spring to clean. Then fix the injector on the vise with a U-turn, loosen the fastening screw sleeve of the coupler, remove the coupler of the injector, and perform the following inspection after necessary cleaning.
The inspection is divided into visual inspection and sliding test. The mating surface of the needle valve and the valve body shall not be burnt or corroded by visual inspection; the shaft needle of the needle valve shall not be deformed or damaged. When doing a sliding test, the valve body must be tilted about 60 degrees, and the needle valve must be pulled out about 1/3 of the stroke and then released. The needle valve should be able to slide down smoothly by its own weight; rotate the needle valve position and repeat the above operation, if The needle valve cannot slide smoothly in any position, and the needle valve assembly should be replaced.
Clean the body and its oil passage, and assemble the pressure regulating spring and the pressure regulating screw together. Note that the pressure regulating screw cannot be tightened too tightly, so that it is convenient for exhaust and overall cleaning during the performance inspection in the later stage. Place the available or replaced needle valve assembly in a plastic basin filled with clean diesel, and move the needle valve back and forth for thorough cleaning. Fix the pressure regulating part of the injector (should be below) on the vise, buckle the needle valve assembly on the joint surface according to the positioning requirements, and then tighten the assembly fastening screw sleeve, and then perform the following performance inspection.
Post time: May-25-2021