This article will describe five things that should be done in the daily maintenance of excavator diesel pump for reference only.
1. 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 determined by checking the sealing condition of the oil outlet valve, which is conducive to determining 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 transfer pump. If it is found that oil flows out from the oil pipe joint at the top of the oil injection pump, it indicates that the oil outlet valve is poorly sealed. If multiple cylinders show poor sealing, the oil injection pump shall be thoroughly commissioned and maintained and the coupling parts shall be replaced.
2. High pressure oil pipes of different sizes shall be applied
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 takes a certain time. In order to ensure the consistent oil supply interval angle of each cylinder, uniform oil supply and stable operation of diesel engine, 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 scale length and pipe diameter shall be replaced. In practical application, 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, so that the length and diameter of the oil pipe vary greatly. 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, the standard high-pressure oil pipe must be used in application.
3. Regularly check the wear of relevant keyways and fixing bolts
Relevant keyways and bolts mainly refer to camshaft keyways, coupling flange keyways, semicircular keys and coupling fixing bolts. Due to long-term application, the camshaft keyway, flange keyway and semicircular key of fuel injection pump are worn, which widens the keyway, the semicircular key is not installed firmly, and the fuel supply advance angle changes; If the key falls, the power transmission fails. Therefore, it is necessary to check regularly and repair or replace the worn parts in time.
4. Replace the worn plunger and oil outlet valve coupling in time
When it is found that the diesel engine starts hard, the power drops and the fuel consumption increases, and the fuel injection pump and injector still do not improve through adjustment, 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 loss of hard starting, increased fuel consumption and insufficient power of the diesel engine caused by the wear of the coupling parts far exceeds the cost of replacing the coupling parts, and the power and economy of the diesel engine will be significantly improved after replacement. Therefore, the worn coupling parts should be replaced in time.
5. Accurately protect the accessories of the fuel injection pump
The side cover of the pump body, oil dipstick, oil filler plug, oil spill valve, oil pool screw plug, oil plane screw, oil pump fixing bolt, etc. shall be intact. These parts 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 can effectively prevent the deterioration of engine oil, and the oil spill valve ensures that the fuel system has a certain pressure without air, etc. Therefore, it is necessary to strengthen the maintenance of these parts, and repair or replace them in time in case of damage or loss.
