Diesel engines with high seconds have high fuel inlet t […]
Diesel engines with high seconds have high fuel inlet temperatures. If the idle running time is too short when the diesel engine is stopped, the plunger couple will expand and contract too fast. If the necessary lubrication is lacking, the plunger will stop. At the time of the micro-bite state, for the high-pressure oil pump with a special oil-filling hole on the sleeve, if the roller stops at the higher position of the fuel roller when the parking is stopped, the plunger is just at the position of the oil-filling hole. The plunger head of the cylinder is in a dry state at the next startup, which inevitably causes the oil pump plunger to jam.
For the oil system of the high-pressure oil pump, in order to avoid the deterioration of the lubrication condition of the plunger coupler, it is also necessary to pay attention to the quality of the lubricating oil and the cleaning of the lubrication passage. It is necessary to strengthen the separation of the lubricating oil and periodically replace the sealing ring in the oil pump. And the crankcase oil to maintain the quality of the oil.
The working environment of the plunger coupler is high temperature, high pressure and reciprocating relative motion, so the even piece will generate thermal expansion during operation. The sleeve is fixed on the body of the high pressure oil pump, and the heat generated by the coupling can be conducted out from the body of the oil pump, and the column is The heat generated by the plug is difficult to conduct in time. If the matching gap of the precision coupler is too small, the plunger is easily stuck.
From the structure of the high-pressure oil pump, the plunger reciprocates in the sleeve, and the rack drives the ring gear and the rotating sleeve to drive the plunger to rotate to change the oil supply. The sleeve is fixed on the high-pressure oil pump body by the positioning screw, so the size of the positioning hole on the sleeve is very important, deep, although it can be tightened but can not function as a fixed sleeve; shallow, after the positioning nail is tightened The sleeve will be topped. This causes the centerline of the sleeve to be concentric with the center of the plunger, thereby reducing the fit clearance of the coupling member, which is locked into the sleeve after operation.
In addition, the high-pressure oil pump is fixed on the diesel engine body by tightening bolts and nuts. When the diesel engine is running, it generates a large vibration, and sometimes the nut will loosen. At this time, the jacking mechanism of the high-pressure oil pump will be under the action of the spring. Tilt outside. The inclination of the pump body exerts a force on the rack of the high-pressure oil pump, and the force affects the correct position of the plunger in the sleeve through the sleeve, which also causes the center line of the plunger and the center line of the sleeve to not coincide, and Causes the plunger to jam in the sleeve.