Causes and maintenance of the failure of the pulling cylinder of agricultural diesel engine

With the development of agricultural machinery and the improvement of people’s living standards, more and more farmers have purchased tractors. When using tractors, it is inevitable that some faults will occur. Especially if the diesel engine fails, the driver will have headaches. The failure of the pull cylinder, introduce its causes and maintenance.

The pull cylinder is a kind of adhesive wear between the piston and the cylinder liner. The wear surface temperature is too high, so that they are fused together. As the piston reciprocates, the adhered part is pulled apart again, causing the cylinder liner and Damage to the surface of the piston.

I.The harbinger of pulling the cylinder

1 The speed of the diesel engine decreases, the power decreases, and it will stop by itself when it is serious; it is difficult to shake the car after parking or can not shake the car.

2 The diesel engine emits a heavy abnormal sound.

3 Cooling water temperature, cylinder temperature, and oil temperature increase significantly.

4 crankcase smoke, can smell the oil burnt.

II.The reason for the pull cylinder

1 cylinder liner is poorly lubricated. If the amount of lubricating oil in the cylinder liner is insufficient, the viscosity of the oil is too large or too small, and the clearance with the piston is too small, the surface of the cylinder liner will be too high due to poor local lubrication and severe friction.

2 cylinder liner and piston overheated. Due to the overload operation of the diesel engine for a long time, the cooling water volume is insufficient or interrupted, the piston ring is seriously leaked, and the fuel injection timing is too late to cause post-combustion, etc., which will cause the cylinder liner and the piston to overheat, resulting in a cylinder accident.

3 piston rod set is poorly aligned or the connecting rod is bent and deformed. Due to improper installation, the center line of the piston rod set is excessively offset from the center line of the cylinder liner, or the connecting rod is bent and deformed in the direction of the piston pin, causing the piston to be biased to one side or skewed, causing severe local surface friction and excessive temperature.

4 poor running-in. Newly installed or repaired diesel engines are required to perform an air-wheel running-in operation to eliminate machining marks on the surface of the parts before the load can be increased. If the running-in is poor, the machining tool marks on the surface of the part are not eliminated, and the load operation is increased, which causes the local surface to heat up due to the friction, resulting in a cylinder accident.

III. Repair of the cylinder failure

When the diesel engine has a cylinder failure, first reduce the load, reduce the throttle, and if necessary, remove the load of the diesel engine and then stop. After parking, let off the cooling water, use the decompression device to open the air valve, shake the handle to turn the flywheel, and discharge the gas in the cylinder. At this time, do not add cold water to the cooling water tank to prevent the cylinder sleeve from shrinking and the piston is stuck in the cylinder. . Finally, the piston connecting rod set is lifted, and the wear of the piston and the cylinder liner surface is checked, and the fine sand layout portion can be used for polishing. Find and eliminate the cause of the pull cylinder before driving.

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