Made In China Fuel Injection Pump Plunger 134151-9120 Pump Elements Engine Parts

The injection pump is the fuel supply unit of the diesel engine and is the key component of the fuel injection system. The plunger coupling is a precision coupling in the injection pump. Driven by the cam-guided piston, the plunger achieves fuel pressurisation and delivery through high-frequency reciprocating motion in the plunger sleeve. The clearance between the plunger and the plunger sleeve is very small, which requires high requirements for design, processing and assembly. If the plunger coupling occurs to bite, it will directly affect the system fuel supply, resulting in the diesel engine can not run normally.

Therefore, it is necessary to make a preliminary inspection and judgement on the possible reasons for the plunger coupling to bite the card, and the following reasons may occur:

(1) The strength of the connecting screw is not qualified. Connection screw hardness is not up to standard, fatigue fracture after a long period of operation, the fracture process may also lead to uneven force on the plunger and bite card phenomenon.

(2) Unqualified plunger material. As the design pressure of this type of injection pump is 140 MPa, the head of the plunger is subjected to the fuel pressure of the high-pressure chamber, which, together with the defects in the heat treatment of the plunger, leads to deformation of the material at high speed of the diesel engine, followed by wear and tear.

(3) Plunger coupling processing quality problems. The machining accuracy of the plunger coupling directly affects the gap between the plunger and the plunger sleeve, resulting in poor lubrication of the coupling, which leads to the plunger coupling easy to produce the phenomenon of jamming.

(4) Problems with the assembly of the injection pump. According to the existing assembly technology requirements, when installing the connecting screw, if the tightening torque is not enough or too large, it will cause the plunger to be unbalanced during the working process, and then it will fail after a long time of operation.