Operation and maintenance of oil pan

Operation and maintenance

Fuel injection pump is an important part of the fuel supply system of diesel generator. Its working condition directly affects the power, economy and reliability of diesel generator. Correct maintenance is an important prerequisite to ensure the normal operation of the fuel injection pump and extend its service life. The following "ten elements" teach you how to maintain the fuel injection pump of the diesel generator:

1、 The accessories of the fuel injection pump shall be properly maintained.

The side cover of the pump body, oil dipstick, filler plug (respirator), oil spill valve, oil pool 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 spill 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 injection pump meet the requirements.

Before starting the diesel generator, check the quantity and quality of oil in the fuel injection pump (except for the fuel injection pump that is forced to be 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 oil, the lighter one will cause early wear of the plunger and oil outlet valve coupling, which will lead to insufficient power of the diesel engine and difficult to start. If it is serious, it will cause corrosion and corrosion of the plunger and oil outlet valve coupling. Due to the internal leakage of the oil pump, the poor operation of the oil outlet valve, the wear of the tappet and the 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, it 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 again after a short time of use. The quantity of engine oil should not be too much or too little. Too much oil in the governor will easily lead to the "flying" of the diesel engine. Too little oil 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, it is necessary to check whether there is water, diesel and other impurities in the oil in the oil pool of the oil pump. If there is any, it should be replaced immediately. Otherwise, due to long-term storage, the water will easily cause the plunger and oil outlet valve to rust and jam and scrap.

3、 Regularly check and adjust the fuel supply quantity of each cylinder of the fuel injection pump.

Due to the wear of the plunger coupling and the oil outlet valve coupling, the internal leakage of diesel oil will reduce or uneven the oil supply of each cylinder, resulting in difficult starting, insufficient power, increased fuel consumption and unstable operation of the diesel engine. Therefore, it is necessary to regularly check and adjust the fuel supply quantity of each cylinder of the fuel injection pump to ensure the power of the diesel engine. In actual use, the fuel supply quantity of each cylinder can be determined by observing the exhaust gas of the diesel generator, listening to the engine sound, and touching the exhaust manifold temperature.

4、 Use standard high-pressure oil pipes.

During the fuel supply process of the fuel injection pump, due to the compressibility of the diesel and the elasticity of the high-pressure oil pipe, the high-pressure diesel will form pressure fluctuations in the pipe, and the pressure wave will take a certain time to transmit in the pipe. 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 the high-pressure oil pipe are determined 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. However, in actual use, due to the lack of standard oil pipes, other oil pipes are used instead, regardless of whether the length and pipe diameter of the oil pipes are the same, so the length and pipe diameter of the oil pipes are greatly different. Although the oil pipes can be used in emergency, the oil supply advance angle and oil supply amount of the cylinder will change, resulting in unstable operation of the whole machine. Therefore, standard high-pressure oil pipes must be used in use.

5、 Check the sealing condition of the valve coupling regularly on the machine.

After 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 inspection, unscrew the high-pressure oil pipe connector of each cylinder and pump oil with the hand of the oil pump. If oil flows out of the oil pipe connector at the top of the fuel injection pump, it indicates that the oil outlet valve is poorly sealed (of course, this will happen if the spring of the oil outlet valve is broken). If the sealing of multiple cylinders is poor, the fuel injection pump shall be thoroughly commissioned and maintained and the coupling shall be replaced.

6、 The worn plunger and oil outlet valve coupling shall be replaced in time.

When it is found that the diesel engine is difficult to start, the power is reduced and the fuel consumption is increased, and the fuel injection pump and injector are still not improved through adjustment, the plunger and outlet valve 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 instead of being reused. The diesel engine is difficult to start, the fuel consumption is increased, the power is insufficient and other losses caused by the wear of the coupling parts far exceed the cost required for replacing the coupling parts. After the replacement, the power and economy of the diesel engine will be significantly improved. Therefore, the worn coupling parts should be replaced in time.

7、 The use and filtration of diesel shall be well controlled to ensure that the diesel entering the injection pump is highly clean.

Generally speaking, the filter requirements of diesel generator for diesel oil are much higher than that of gasoline engine for gasoline. In use, diesel oil with the required grade shall be selected and precipitated for at least 48h. Strengthen the cleaning and maintenance of the diesel filter, and timely clean or replace the filter element; Clean the diesel tank in time according to the operating environment conditions to thoroughly remove the oil sludge and water at the bottom of the tank. Any impurities in the diesel will cause serious corrosion or wear to the plunger of the injection pump, the oil outlet valve coupling and the transmission parts.

8、 Regularly check and adjust the fuel supply advance angle of the fuel injection pump and the fuel supply interval angle of each cylinder.

During use, due to the looseness of the coupling bolts and the wear of the camshaft and roller body parts, the oil supply advance angle and the oil supply interval angle of each cylinder often change, resulting in the deterioration of the diesel combustion, the deterioration of the power and economy of the diesel engine, and the difficulty in starting, unstable operation, abnormal noise and overheating. In actual use, most drivers attach importance to the inspection and adjustment of the overall fuel supply advance angle, but neglect the inspection and adjustment of the fuel supply interval angle (involving the adjustment of the single pump fuel supply advance angle). As a result, although the fuel supply timing of the first cylinder is adjusted as a whole, the fuel supply timing of the remaining cylinders is not necessarily due to the wear of the camshaft and roller drive components, which will also lead to difficulties in starting the diesel engine, insufficient power and unstable operation, Especially for the fuel injection pump that has been used for a long time, more attention should be paid to the inspection and adjustment of the 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 and 0.15mm. If the clearance is too large, it will intensify the impact of the roller drive parts on the working surface of the cam, thus increasing the early wear of the cam surface and changing the oil supply advance angle; Too large clearance between the camshaft bearing shaft and the diameter is easy to cause unstable operation of the camshaft, shaking of the oil quantity adjusting rod, and periodic change of the oil supply quantity, resulting in unstable operation of the diesel engine. Therefore, regular inspection and adjustment are required. If the axial clearance of camshaft is too large, shims can be added on both sides for adjustment. If the radial clearance is too large, new products should be replaced.

10、 Regularly check the wear of relevant keyways and fixing bolts.

Relevant keyways and bolts mainly refer to camshaft keyways, coupling flange keyways (oil pumps transmitting power through couplings), half round keys and coupling fixing bolts. The camshaft keyway, flange keyway and semicircular key of the fuel injection pump are worn due to long-term use, which makes the keyway wider, the semicircular key is not installed firmly, and the oil supply advance angle is changed; If the key falls, the power transmission will fail. Therefore, it is necessary to check regularly and repair or replace the worn parts in time.