DK28 diesel engine parts explain the cause of diesel engine runaway and its treatment

Diesel engine runaway refers to the phenomenon that the speed is out of control, greatly exceeds the rated speed, the engine vibrates violently, makes a roar, and the exhaust pipe emits a lot of black smoke or blue smoke. The flying car not only causes damage to the parts, but also endangers the personal safety of the pilots, which should be taken seriously by the crew.      

The main causes of diesel speeding include oversupply of fuel and overburning of engine oil. Although both types of speeding have diesel engine speeding, their specific performance is different. When diesel oversupply causes speeding, the exhaust pipe emits black smoke. Generally, it can be stopped by cutting off the fuel supply; when the oil causes the diesel engine to speed, the exhaust pipe emits blue smoke. At this time, only cutting off the fuel supply cannot effectively stop it. Air supply and rapid decompression to stop.

The specific reasons for diesel engine runaway caused by diesel oversupply are as follows:  

(1) The ball head of the plunger adjusting arm or the gear lever adjusting arm does not enter the adjusting fork groove, and the plunger is at the maximum oil supply position. 

(2) The oil pump plunger does not rotate properly, which is a common cause of diesel engine running fast. The plunger is at the maximum oil supply position, and the governor cannot be pulled, so that the speed increases, and the governor cannot control the amount of oil. The reasons for the ineffective rotation of the plunger include the plunger being bumped during assembly; the dirt in the oil pump causes impurities to enter the gap of the plunger pair; the torque is too large when the oil outlet valve seat is tightened, which causes the plunger sleeve to deform; The gasket on the plug sleeve positioning screw is too thin, and the positioning screw bears against the plunger sleeve and deforms it; the plunger sleeve positioning screw is too long or bent, and the plunger sleeve is deadlocked during assembly.

(3) After the fuel injector is worn, a large amount of return oil connected to the intake pipe is sucked into the cylinder, causing excessive fuel in the cylinder.

(4) When installing the governor, there is too much butter on the steel ball, and the butter is too viscous, making it difficult for the steel ball to fly away when the speed increases.

(5) The gear rod and gear ring has no mark or is installed incorrectly, and the plunger is installed reversely.

(6) The injection pressure is low, and the fuel supplied to the cylinder is excessive.

(7) The tie rod is stuck with the movable part of the governor.

(8) Improper commissioning of the governor, due to the fact that the operator deliberately increased the single-cylinder diesel. The preload of the speed regulating spring of the engine; The action point of the governor of No. II pump is too high, resulting in a high speed or failure to stop the oil; There is too much lubricating oil in the governor or the viscosity is high.