The oil sump is located at the lower part of the engine: it can be disassembled, and the crankcase seal is used as the shell of the oil storage tank. The oil pan is mostly stamped by thin steel plate. The complex shape is generally cast by cast iron or aluminum alloy. An oil stabilizing baffle is installed inside to avoid the oil level shock and splash caused by the turbulence of the diesel engine, which is conducive to the precipitation of lubricating oil impurities. A dipstick is installed on the side to check the oil volume. In addition, the lowest part of the bottom of the oil pan is also equipped with an oil drain plug.
1、 Properly maintain the accessories of the fuel injection pump.
The side cover of the pump body, oil dipstick, oil filler plug (respirator), oil overflow valve, oil pool screw plug, oil plane screw, oil pump fixing bolt, etc. shall be intact. These accessories play a vital role in the work of the fuel injection pump. For example, the side cover can prevent the invasion of dust, water and other impurities, the respirator (with filter screen) can effectively prevent the deterioration of engine oil, and the oil overflow valve ensures that the fuel system has a certain pressure without entering air. Therefore, it is necessary to strengthen the maintenance of these accessories, and repair or replace them in time in case of damage or loss.
2、 Always check whether the oil quantity and quality in the oil pool of the fuel injection pump meet the requirements.
Before starting the diesel generator every time, check the quantity and quality of oil in the fuel injection pump (except the fuel injection pump forcibly lubricated by the engine) to ensure that the quantity of oil is sufficient and the quality is good. If the oil deteriorates due to mixing with water or diesel, it will cause early wear of plunger and oil outlet valve coupling, resulting in insufficient diesel power and difficult start, If it is serious, the plunger and oil outlet valve coupling parts will be corroded. Due to the internal leakage of the oil pump, the poor operation of the oil outlet valve, the wear of the tappet and shell of the oil transfer pump and the damage of the sealing ring, the diesel oil will leak into the oil pool and dilute the oil. Therefore, the oil should be replaced in time according to the quality of the oil. During the replacement, the oil pool should be thoroughly cleaned and the oil sludge and other impurities at the bottom of the oil pool should be removed, otherwise the oil will deteriorate after a short period of use. The quantity of oil shall not be too much or too little. Too much oil filling in the governor will easily lead to "flying" of the diesel engine. Too little oil filling will lead to poor lubrication. The oil dipstick or oil plane screw shall prevail. In addition, when the diesel engine is not used for a long time, be sure to check whether there are water, diesel and other impurities in the oil in the oil pool of the oil pump. If so, replace it immediately. Otherwise, due to long-term storage, the water is very easy to rust and block the plunger and oil outlet valve coupling and scrap it.
3、 Regularly check and adjust the fuel supply of each cylinder of the fuel injection pump.
Due to the wear of plunger coupling and oil outlet valve coupling, diesel internal leakage will reduce or uneven oil supply of each cylinder, resulting in difficult starting, insufficient power, increased fuel consumption and unstable operation of diesel engine. Therefore, regularly check and adjust the fuel supply of each cylinder of the fuel injection pump to ensure the exertion of diesel engine power. In practical use, the fuel supply of each cylinder can be determined by observing the smoke exhaust of diesel generator, listening to the sound of engine and touching the temperature of exhaust manifold.
4、 Use standard high pressure tubing.
During the fuel supply process of fuel injection pump, due to the compressibility of diesel and the elasticity of high-pressure oil pipe, high-pressure diesel will form pressure fluctuation in the pipe, and the transmission of pressure wave in the pipe will take a certain time. In order to ensure that the oil supply interval angle of each cylinder is consistent, the oil supply quantity is uniform and the diesel engine works stably, the length and diameter of high-pressure oil pipe are selected through calculation. Therefore, when the high-pressure oil pipe of a cylinder is damaged, the oil pipe with standard length and pipe diameter shall be replaced. In actual use, due to the lack of standard oil pipe, other oil pipes are used instead, regardless of whether the length and diameter of the oil pipe are the same, resulting in a great difference in the length and diameter of the oil pipe. Although it can be used in emergency, it will lead to changes in the oil supply advance angle and oil supply quantity of the cylinder, resulting in unstable operation of the whole machine. Therefore, standard high-pressure oil pipe must be used in use.
5、 Check the sealing condition of valve coupling parts on the machine regularly.
When the fuel injection pump works for a period of time, the wear of the plunger and the working condition of the oil pump can be roughly judged by checking the sealing condition of the oil outlet valve, which is helpful to determine the repair and maintenance methods. During the inspection, unscrew the high-pressure oil pipe joint of each cylinder and pump the oil with the hand of the oil pump. In this case, if the oil pipe joint at the top of the fuel injection pump is found to have oil flowing out, it indicates that the oil outlet valve has poor sealing (of course, this will also happen if the oil outlet valve spring is broken). If the sealing of multiple cylinders is poor, the fuel injection pump shall be thoroughly commissioned and maintained and the coupling parts shall be replaced.
6、 Replace the worn plunger and oil outlet valve coupling in time.
When it is found that the diesel engine is difficult to start, the power decreases and the fuel consumption increases, and the fuel injection pump and injector are still not improved by adjusting, the plunger and outlet valve coupling of the fuel injection pump shall be disassembled and inspected. If the plunger and outlet valve are worn to a certain extent, they shall be replaced in time and shall not be reused. The losses caused by the wear of the coupling parts, such as difficult starting of the diesel engine, increased fuel consumption and insufficient power, far exceed the cost of replacing the coupling parts. The power and economy of the diesel engine will be significantly improved after replacement. Therefore, the worn coupling parts should be replaced in time.
7、 The use and filtration of diesel oil shall be well controlled to ensure that the diesel oil entering the fuel injection pump is highly clean.
Generally speaking, the filtering requirements of diesel generator for diesel oil are much higher than those of gasoline engine. Diesel oil meeting the required brand shall be selected during use, and it shall be precipitated for at least 48 hours. Strengthen the cleaning and maintenance of diesel filter, and timely clean or replace the filter element; Clean the diesel tank timely according to the operating environmental conditions to completely remove the oil sludge and moisture at the bottom of the tank. Any impurities in the diesel will cause serious corrosion or wear to the plunger of the fuel injection pump, outlet valve coupling and transmission components.
8、 Regularly check and adjust the fuel supply advance angle of the fuel injection pump and the fuel supply interval angle of each cylinder.
When in use, due to the loose coupling bolts and the wear of camshaft and roller body parts, the oil supply advance angle and oil supply interval angle of each cylinder often change, so that the diesel combustion is bad, the power and economy of the diesel engine are poor, at the same time, it is difficult to start, unstable operation, abnormal noise and overheating, etc. In actual use, most drivers pay attention to the inspection and adjustment of the overall fuel supply advance angle, but ignore the inspection and adjustment of the fuel supply interval angle (involving the adjustment of the fuel supply advance angle of a single pump). As a result, although the fuel supply timing of the first cylinder is adjusted as a whole, the fuel supply timing of other cylinders is not necessarily due to the wear of camshaft and roller transmission parts, which will also lead to the difficulty of starting the diesel engine Insufficient power and unstable operation, especially for fuel injection pumps that have been used for a long time, we should pay more attention to the inspection and adjustment of fuel supply interval angle.
9、 Check the camshaft clearance regularly.
The axial clearance of the camshaft of the fuel injection pump is very strict, generally between 0.03 ~ 0.15mm. If the clearance is too large, it will aggravate the impact of the roller transmission parts on the working surface of the cam, so as to increase the early wear of the cam surface and change the oil supply advance angle; The clearance between camshaft bearing and shaft diameter is too large, which is easy to cause unstable operation of camshaft, jitter of oil quantity adjustment pull rod, periodic change of oil supply, and unstable operation of diesel engine. Therefore, regular inspection and adjustment shall be carried out. When the axial clearance of camshaft is too large, shims can be added on both sides for adjustment. If the radial clearance is too large, it is generally necessary to replace it with a new one.
10、 Regularly check the wear of relevant keyways and fixing bolts.
Relevant keyways and bolts mainly refer to camshaft keyway, coupling flange keyway (oil pump transmitting power by coupling), semicircular key and coupling fixing bolt. The camshaft keyway, flange keyway and semicircular key of fuel injection pump are worn due to long-term use, which widens the keyway, the semicircular key is not installed firmly, and the fuel supply advance angle is changed; If the key falls, the power transmission fails. Therefore, it is necessary to check regularly and repair or replace the worn parts in time.
