The fuel pump assembly is the core component of the diesel engine fuel system. The understanding of the role, structure, and classification of the fuel injection pump in the diesel engine is an important part of understanding the engine. Fuel injection system expert--Guangzhou Ruixiao Trading Co., Ltd. has been engaged in the operation of spare parts for decades, whether it is the components of fuel injection pump, such as plunger, oil outlet valve, repair kit, governor, oil pump, advancer and other components. , or have a unique insight and deep understanding of the correct use and troubleshooting of the fuel injection pump, now the experts from Ruixiao company to introduce you about the diesel engine fuel pump assembly.
First, the role
1. Increase oil pressure (constant pressure): Increase the injection pressure to 10 MPa to 20 MPa.
2. Control injection time (timing): Inject oil and stop injection at the specified time.
3. Control the fuel injection amount (quantitative): According to the working condition of the diesel engine, change the amount of fuel injection to adjust the speed and power of the diesel engine.
Second, the requirements of the fuel injection pump
1. The oil is supplied in the order of the diesel engine operation, and the oil supply amount of each cylinder is uniform.
2. The oil supply advance angle of each cylinder should be the same.
3. The fuel supply duration of each cylinder should be equal.
4. The establishment of oil pressure and the stopping of oil supply must be rapid to prevent the occurrence of dripping.
Third, the classification of fuel pump assembly
1. Plunger type fuel pump assembly.
2. The pump-injector
type combines the fuel injection pump and the injector.
3. Rotor-distributed fuel injection pump.
Fourth, the structure of a typical fuel injection pump
The diesel fuel injection pumps commonly used in China are: A-type pump, B-type pump, P-type pump, VE-type pump, etc. The first three are piston pumps; the VE pumps are distributed rotor pumps.
(1) Structural features of the B-type fuel injection pump
1. Adopting a spiral groove plunger and a flat hole plunger sleeve;
2. The oil quantity adjusting mechanism is a rack type, and an adjustable maximum oil amount rigid limiter (some spring limiters) is installed at the front end of the rack rod;
2. Adjusting the screw type roller body transmission component;
3. The camshaft is a tangential cam that is supported on the housing by tapered roller bearings.
4. The pump body is monolithic and is independently lubricated.
(II) Structural features of P-type fuel injection pump
1. Suspended sub-pump assembly Parts such as the plunger and plunger sleeve, the oil discharge valve are fixed together with a split-disc pump steel sleeve to form an assembly. It is directly fixed to the casing with a gold stud to form a suspended structure. The sleeve can be rotated a certain angle.
2. Adjustment of the oil supply amount of each sub-pump There is an arc groove on the flange plate of the sub-pump steel sleeve, loosen the compression stud, and rotate the steel sleeve, and the plunger sleeve of the sub-pump is rotated with a certain angle to change The return oil time changes with respect to the position of the oil hole relative to the chute on the plunger.
3. The adjustment of the fuel supply starting point of the sub-pump increases or decreases the gasket under the flange disc sleeve, so that the inlet and outlet oil holes of the plunger sleeve move up and down slightly, thereby changing the position relative to the upper end of the plunger, and adjusting the position of the sub-pump The starting point of the oil supply.
4. The ball pin angle plate oil adjusting mechanism is welded with 1~2 steel balls on the end face of the transmission sleeve, and the cross section of the oil supply rod is in the shape of an angle steel, and a small square notch is opened on the horizontal right side edge thereof, and the working slot is square. Engages with the steel ball on the drive sleeve. Non-adjustable roller body transmission components;
5. Fully enclosed box type pump body The integrated sealed pump body without side window, only the upper cover and the lower cover, the price of the diesel fuel generator set. The pump body has high rigidity and can withstand high injection pressure without deformation, so that the life of the plunger coupler is longer;
6. Pressure lubrication is adopted;
7. There is a special preparatory stroke inspection hole. There is a screw plug above the roller body, which can be used to check whether the sub-pump preparation stroke is consistent (measured by a special instrument).