In the long-term work of the diesel generator injector needle valve, due to the erosion of high pressure oil, the grinding of mechanical impurities and the setting of the pressure spring, the matching surface of the needle valve and the valve body will be worn, which will cause the leakage before the oil injection and the drip of oil after the oil is cut off, resulting in poor atomization, incomplete combustion, a sharp increase in carbon smoke, and serious carbon accumulation. Therefore, the injector must be regularly maintained and maintained.
(1) The injector of the generator set is removed from the cylinder head for a simple external cleaning, and then disassembled, inspected, and assembled one by one to prevent the same parts of different injectors from mixing with each other during assembly. The specific steps are: first clamp the injector hole down on the pliers, remove the pressure regulator screw protection cap, pressure regulator screw and spring clean. Then fix the injector head on the vice, loosen the coupling fastening screw sleeve, remove the injector coupling, and carry out the following inspection after necessary cleaning.
(2) The inspection is divided into visual inspection and sliding test
The matching surface of the needle valve and the valve body shall not be burned or corroded. The needle of the needle valve must not be deformed or otherwise damaged. For sliding test, the valve body should be tilted about 60 degrees, and the needle valve should be released after about 1/3 stroke, and the needle valve should be able to slide smoothly by its own weight; Rotate the needle valve position and repeat the above operations. If the needle valve does not slide smoothly in any position, replace the needle valve pair.
(3) Assembly
Clean the body and its oil passage, and assemble the pressure regulating spring and pressure regulating screw. Note that the pressure regulator screw should not be tightened too tightly, so that it is easy to exhaust and overall cleaning during the later performance check. Place the usable or replaced needle valve pair in a plastic basin with clean diesel oil and clean the needle valve thoroughly by moving the oil back and forth. Make the pressure regulating part of the injector (should be at the bottom) fixed on the vice, fasten the needle valve couple on the joint surface according to the positioning requirements, and then tighten the tightening screw sleeve of the couple, and then perform the following performance check.
Performance check of injector in generator set
Check the injection pressure and atomization condition of the injector of the generator set should be carried out on the test instrument of the injector of the generator set. The test instrument is composed of a manual oil pump, a pressure gauge and an oil storage tank. The diesel oil in the oil tank enters the manual oil pump, and the high-pressure diesel oil after being pressurized enters the injector and is sprayed in a fog.
(1) Check the injection pressure
During the inspection, relax the pressure regulator screw on the injector of the generator set, install the injector on the test instrument, and repeatedly press the handle on the test instrument up and down, so that the injector and high pressure oil pipe are completely filled with diesel. Then slowly press the handle, while paying attention to the oil pressure gauge reading. When the reading begins to drop, that is, the opening pressure of the injector, and its value should meet the standard requirements. For example, the injection pressure of the 6135 generator set is 17.5Mpa, otherwise it should be adjusted. Most of the pressure regulation methods of the fuel injector of domestic generator set are realized by adjusting the pressure regulating screw to change the preload of the pressure regulating spring. For individual imported models, the pressure is adjusted by changing the degree of the gasket, such as Toyota L series diesel engines in Japan.
(2) Inspection of injection quality
The handle of the tester should be slowly and continuously pressed down to check the injection quality of the injector. For the porous injector, the oil emitted from each jet hole should form a small cone oil bundle with good atomization, and the interval Angle of each oil speed should meet the original regulations. For the needle injector, the spray is required to be conical, not skewed, and the oil mist should be small and uniform.
The injector with good performance should have obvious and clear cracking sound when spraying oil, the atomization cone Angle should meet the requirements, and there is no dripping oil after it, otherwise the injector should be cleaned again or the couple should be replaced.
Press the handle of the tester, control the oil pressure to 0.98-1.98MPA, and do not leak around the spray hole and fastening nut within 10S, otherwise it should be reassembled and adjusted. If it does not meet the requirements, it should be replaced with a new pair.
Overall assembly of fuel injector
When the adjusted injector is assembled as a whole, special attention should be paid to the installation of the pressure regulating screw fastening nut, otherwise the debugging quality will be affected. The correct installation method is: clamp the injection hole of the fuel injector down on the pliers, and use a small one-head screwdriver in the right hand to pass through the oil return screw hole of the pressure regulator screw fastening the nut, and fix the pressure regulator screw; With the left hand, use a wrench to tighten the tightening nut of the pressure regulating screw. The purpose of this is to ensure that the original position of the pressure regulator screw is not moved when the pressure regulator screw and the nut are tightened again.
For more questions about the generator set, please call the Beidou Power team. More than ten years of professional production and sales of power generation equipment experience, more professional engineer team to serve you, choose Beidou power is to choose rest assured, welcome on-site factory inspection.
Post time: Jan-24-2025