Diesel generator maintenance training diesel engine -p56-p60 pump body

(5) Pump body

The physical appearance of the diesel generator fuel injection pump body is shown in Figure 2-69. There is a part mounting hole at the end of the pump body for the installation of the plunger coupler, the outlet valve assembly, the outlet valve pressure spring and the outlet valve seat. A low-pressure oil passage is drilled on one side of the pump body, and it communicates with the oil inlet hole of the plunger sleeve of each cylinder. There are two low pressure oil passage bleeder screws on the left and right sides of the pump body. Each cylinder has a plunger sleeve positioning hole on the outside. Below the positioning hole is the inspection hole, which is mainly used to adjust the supply of oil to the sub-pump, fuel supply and inspection of the internal parts of the work, usually sealed with a flat cover. At the F-end of the inspection hole, there is an oil pump oil gauge inspection hole. There are four screw fixing holes on the front and rear of the pump body for fixing the pump body. The L1 platform below the pump body is used to install the oil pump. The round hole at the bottom of the pump body is used to install and remove the wheel body. A camshaft is mounted in the middle of the lower part of the pump body. The upper part of the steam turbine shaft is a roller body, and the left side is fixed to the coupling on the coupling through a semicircle key.

The left side of the pump body is equipped with an oil amount control mechanism, loosen the lock nut, and turn the oil amount adjustment screw to change the fuel supply of the fuel injection pump.

The physical decomposition of the fuel injection pump is shown in Figure 2-70.

(6) Faults and causes of failure of the fuel injection pump.

The diesel engine fuel injection pump prone to failures are: non-injection or fuel injection does not meet the technical requirements: the amount of uneven spraying of each cylinder: the plunger sleeve and the pump body contact position oil leakage; fuel supply advance angle is too large or Too small: excessive wear of the plunger coupler and the outlet valve assembly; jamming or jamming when the plunger rotates in the plunger housing: the plunger spring is damaged.

The reason why the fuel injection pump does not spray 5N or the spray gauge does not meet the technical requirements is as follows:

1 Fuel injection pump There is air in the low pressure oil gallery.

2 Severe wear of individual plunger and outlet valve parts.

2 The plunger is stuck in the smallest position of the plunger sleeve or the plunger spring is damaged.

4 The oil valve stuck on the outlet valve seat or the outlet valve spring was damaged.

6 adjust the tooth bar stuck and so on.

The common causes for uneven spraying of cylinders of diesel generator fuel injection pumps are as follows:

1 Air enters the low pressure oil passage of the injection pump.

2 Loosening of the set screw on the boise adjustment gear results in a change in the effective stroke of the plunger.

2 Outlet valve parts are seriously worn or the outlet valve spring is damaged.

4 The wear gap between the plunger lug and the oil control sleeve is too large, causing the effective stroke of the lug to move left and right.

Oil leakage of the diesel generator set plunger sleeve and the pump body is generally caused by the damage of the gasket between the plunger sleeve and the pump body or the deformation of the pump body in contact with the gasket. The damage of the gasket is caused by the excessive mounting torque of the outlet valve or the poor quality of the gasket.

If the fuel supply advance angle is too large or too small, it is generally caused by the loosening of the two fixing screws of the upper connecting basin of the fuel injection pump coupling. In addition, under certain circumstances excessive wear of pump transmission parts, loosening of wheel adjustment screws, damage to outlet valve springs, excessive clearance of plunger wear, damage to the plunger spring inside the inspection hole, and leakage in the fuel supply system Such as, will cause the fuel supply lead angle is too large or too small.

The main cause of excessive wear of the plunger coupler and the outlet valve is excessive impurities in the diesel fuel, the needle valve inside the injector is stuck or the outlet valve is stuck in the outlet valve sleeve.

The main reason for the jam or jamming of the plunger when it rotates in the plunger sleeve is that diesel has many internal impurities and enters between the plunger and the plunger sleeve, or the diesel label used in winter is incorrect. In addition, in some cases, the tightening torque of the tight seat of the oil valve does not conform to the technical requirements and the plunger sleeve is deformed. The gap between the upper end of the plunger and the bottom plane of the exit valve is too small, etc., and the plunger is also in the plunger sleeve. A stuck or stuck phenomenon occurs when turning inside.

The reason for the loss of the plunger spring is generally that the diesel engine does not start for a long time, the water in the pump or the quality of the spring does not meet the requirements. After the spring is damaged, the new spring is directly replaced without repair.

(7) Troubleshooting Methods

The diesel generator set injection pump is one of the precision components of the mid-engine diesel engine. When a fuel injection pump malfunctions, a special technician is required to use the injection pump test stand to debug and repair the fuel injection pump assembly. The physical appearance of the injection pump test bench The troubleshooting method when the fuel injection pump does not inject fuel or the fuel injection does not meet the technical requirements is as follows:

1 Before the test, the injection pump must be mechanically inspected. After installing the fuel injection pump on the test stand bracket, turn the camshaft of the fuel injection pump by hand. When there are no seizures in the components, the toothed rod and all moving parts can move flexibly, and then check the internal oil amount of the fuel injection pump assembly. After all preparations are completed, the fuel injection pump adapter is assembled on the rotating shaft of the test stand, and the corresponding high pressure tubing and injection pump low pressure tubing of each cylinder are again connected. When correcting the fuel injector, the air in the low pressure oil passage of the fuel pump should be drained and corrected, as shown in Figure 2-72.

2 is to turn on the main power switch and loosen the fuel pump bleeder screw.

2 Press the low pressure oil pump motor button until the air in the low pressure oil passage of the fuel injection pump is drained. Then tighten the fuel pump bleeder screw.

4 Based on the fuel supply data, check the idle speed of the fuel injection pump and the full-load fuel supply. When individual cylinders do not spray fuel or the fuel injection volume does not meet the technical requirements, first according to the method shown in Figure 2-73, use a flat-blade screwdriver to loosen the lock screw on the oil level adjustment gear ring. Then, according to the method shown in Figure 2-74, push the adjusting hole on the upper part of the gear chamber with a screwdriver to make the gear ring slowly rotate to change the effective stroke of the sample plug, so as to achieve the purpose of changing the fuel supply. . Note: When the oil volume adjustment gear is rotating, the single-cylinder oil supply is reduced; when the oil volume adjustment gear ring rotates to the right, the single-cylinder oil supply increases.

2 If the above fault cannot be discharged after adjustment, check the next step. First remove the oil valve tight seat, and then use a special tool to take out the oil valve and plunger parts for inspection. If the outlet valve coupler and plunger coupler wear out severely, new parts of the same model can be replaced. After replacing the new parts, the idle pump speed and full-load fuel supply of the fuel injection pump shall be separately checked according to the berthing data until the fuel supply requirement is met.