Common faults and troubleshooting of tractors
1、 Causes of tractor failure
(a) Natural factorsSuch as parts wear, parts vibration, machine aging, internal pollution and other factors. Due to the above factors, the gap between tractor parts becomes larger, the connection is loose, the seal is not tight, and the operation is not normal. If it is not repaired and maintained in time, it will break down.
(b) Human factors
Such as poor manufacturing and maintenance quality, improper operation and adjustment, etc. For example, the raw materials for manufacturing parts are poor, the accuracy is not high, and the surface finish and heat treatment do not meet the requirements; Failure to maintain as required; Overload operation for a long time, sudden lifting or stepping on the clutch, large angle change, etc. The water tank is short of water or oil, etc. These factors are not caused for a long time, but formed or suddenly occurred in a short time. Human factors are unpredictable.
2、 Manifestations of tractor faults
(a) Loss of function
Unable to start, lift agricultural machinery, automatic shutdown, etc. Because the automatic shift exits, the generator is not charged, and the oil pipe is blocked.
(b) Abnormal performance
Such as insufficient power, unstable operation, abnormal sound, etc. It is mainly caused by the wear, aging and gradual falling off of parts. It usually presents black smoke, white smoke or blue smoke; Water leakage, oil leakage, light failure; Difficult starting, unstable speed, low oil pressure, invalid clutch operation, insufficient generator power or no power generation, etc. The exhaust pipe has shooting sound, and the gearbox and central transmission have abnormal sound; Smell is the burning of rubber or friction plate or insulating material.
(a) Black, white or blue smoke
1. Black smoke is the free carbon exhaust pipe caused by incomplete combustion of fuel due to the poor state of fuel supply system, air supply system or engine compression system. First, the oil-gas ratio is not adjusted properly, and the position of individual cylinder plunger adjusting rod joint and oil pump rod moves, resulting in excessive oil supply to the cylinder. In this case, the positions of the cylinder plunger adjusting rod and the oil pump rod should be adjusted. Second, the atomization quality of the nozzle is not high, and the fuel is not completely burned, resulting in black smoke. This phenomenon is caused by the weakening or fracture of the nozzle pressure regulating spring. Third, the fuel supply advance angle is incorrect or slightly small, and the fuel is not completely burned and discharged with the air pipe. Black smoke also has air system factors. First, the air filter is blocked, resulting in poor ventilation; Second, the exhaust is not clean and the combustion is not complete, resulting in black smoke. The reason is that the valve clearance becomes larger, the valve spring is damaged, the elasticity is insufficient or the valve carbon deposits; Third, overload operation.
2. White smoke is caused by no fuel burning, too much water in the fuel, or water leaking into the cylinder. The reasons for this phenomenon are: first, the engine temperature is too low, and the fuel is discharged before complete combustion, while the unburned fuel is white fog. Secondly, the cylinder gasket is damaged or burned, and cold water enters the cylinder. Under the action of high temperature and high pressure of the steel cylinder, cold water is discharged into the air duct in the form of water mist. Third, the fuel supply is not timely, the unburned fuel cannot be completely burned, and the unburned fuel is atomized out of the gas pipe. Fourth, the fuel injector drips backward, the needle valve of the fuel injector is stuck in the open position or the pressure spring of the fuel injector is broken. The oil entering the cylinder cannot be atomized, and it will be discharged from the cylinder after incomplete combustion. Fifth, the plunger pair is worn or of poor quality, poor sealing, delayed fuel injection, incomplete combustion in the cylinder and exhaust. Sixth, the fuel quality is poor, the ignition point is high, and the combustion time lags behind. The fuel is discharged from the cylinder before it is completely burned. Seventh, the fuel injector assembly is not tight, resulting in partial incomplete combustion of fuel out of the exhaust cylinder. Eighth, the lubricating oil is insufficient or poorly lubricated, and the valve is stuck in the open position, so that the cylinder cannot normally promote contraction, resulting in incomplete fuel combustion.
3. Blue smoke is caused by burning engine oil. The reasons for this phenomenon are: first, the cylinder taper and ovality of the compression system exceed the standard, the gap between the cylinder and the piston is too large, the opening gap and side gap of the piston ring are too large, the opening of the piston ring coincides, the piston ring deposits carbon, the elasticity becomes smaller, and the position and direction of the torsion ring or conical ring are incorrect; Second, the cylinder strain is large; Third, the clearance between valve and valve guide is too large; Fourth, the oil volume of the oil pan of the air filter is too high; Fifth, the oil volume of the sump is too high; Sixth, there is no running in period after the new car or overhaul; Seventh, the fuel quality is poor, and there are more adulterated oil products.
(b) Difficult engine starting
The main reasons why the engine is difficult to start are excessive oil accumulation in the fuel system, air filter, combustion chamber and insufficient cylinder compression.1. Fuel system problems. First, the diesel is used up or the fuel tank switch is not opened; Second, the air enters the oil circuit, causing the oil circuit to be blocked; Third, the fuel pipeline or diesel filter is blocked; Fourth, the fuel injector does not inject fuel; Fifth, the plunger is seriously worn; Sixth, the sealing of the needle valve of the oil outlet valve is damaged; Seventh, the needle and seat hole of the oil outlet valve are supported by foreign matters; Eighth, the injection pressure is too low or the oil supply time is too long or too short; Ninth, the fuel pump does not supply oil.
2. The air filter is mainly caused by the blockage of the air filter, exhaust pipe or silencer.
3. If there is too much oil in the combustion chamber, pull the throttle handle to the oil-free position, pull the pressure reducing handle to open the valve, turn the crankshaft and drain the oil.
4. The compression force of the cylinder is insufficient because: first, the position of the pressure reducing handle is wrong and it is still in the pressure reducing position; Second, the cylinder head gasket leaks; Third, the piston ring is worn; Fourth, when the valve leaks, check the valve clearance, valve spring, valve guide and valve seat sealing.
