The low-pressure oil circuit is mai

The low-pressure oil circuit is mainly composed of the fine fuel filter, the inlet and return pipeline and the pressure regulating valve, etc., and the fuel circuit plays an auxiliary role in oil storage, oil supply, oil return, filtration, preheating and regulation. The fuel oil fine filter is composed of two sets of paper filter elements, a housing and a common filter body, with a filtration accuracy of up to 12 m. Fuel oil from the locomotive fuel tank through the fuel oil filter, fuel pump pump installed in the front of the diesel engine fuel filter, after filtering into the left and right of the diesel engine oil inlet main line, and then through the various oil inlet branch pipe into the fuel injection pump. The fuel line before the injection pump is the inlet line. To ensure the normal operation of the fuel injection pump, the fuel pressure of the inlet line should be kept between 0.15-0.35mpa. The operating pressure of the pressure regulating valve is 0.12mpa, which keeps a certain pressure on the fuel inlet and return pipelines of the injection pump to ensure sufficient and stable fuel supply when the pump is working.High pressure oil line is composed of fuel injection pump, high pressure oil pipe, fuel injector and other parts. The function of the high-pressure injection system is to inject a certain amount of foggy fuel with a certain amount of pressure into the cylinder at the optimal time and within a certain time according to the operation condition of the diesel engine, to fully mix and burn with the air in the cylinder. In the high pressure volume of the fuel system, the elasticity of the high pressure tubing is more obvious. The expansion and contraction of tubing will affect the transfer of fuel pressure, resulting in the difference between the start point of fuel supply and the start point of fuel injection, as well as the difference between the oil supply and fuel injection rules. This effect increases with the increase of the speed of diesel engine, the length of high-pressure oil pipe and the volume of high-pressure oil pipe. Therefore, a monomer fuel injection pump for each cylinder is adopted to make the fuel injection pump close to the fuel injector, so as to shorten the length of high-pressure tubing as far as possible, and the length of high-pressure tubing for each cylinder is required to be equal. As the core of the fuel system, the parts of the high-pressure oil pipeline work under the environment of high temperature, high pressure and high impact force, so it is one of the parts with the highest failure frequency.