In the work of the tractor, the wear and aging of the parts is inevitable, which makes its technical state deteriorate, the power decreases, the fuel consumption increases, and the failure continues to appear. In order to prevent the occurrence of failure, timely and correct maintenance of the tractor should be carried out to extend the service life of the tractor and reduce the cost of use. In the process of research on the technical status of agricultural tractors, it was found that the maintenance of some parts did not get due attention, resulting in many adverse consequences.
1 Neglect the maintenance of diesel filter
Diesel filter has been acting as the role of scavenger, the most important role is to filter out diesel particles and moisture, for the normal operation of the engine escort. However, many diesel drivers believe that each time the diesel is filled after a long time of precipitation, the impurities and water in the oil are already very clean, and choose to give up the installation or do not maintain the diesel filter for a long time, in fact, this is often penny wise and pound foolish.
Diesel filters are generally used for 200 to 300 hours, and the filter element should be checked and cleaned or replaced. The following points should be noted:
(1) The sealing parts of the air filter assembly are not allowed to leak, do not distort the sealing ring when installing, and install it firmly.
(2) Clean the filter element regularly, the paper filter element can not be cleaned with diesel, and must be brushed with a soft brush or air cylinder blowback. The filter element should be replaced when it is cracked or blocked. The oil bath air filter should be replaced regularly, the oil pan should be cleaned, and the oil should be refueled to the appropriate height, not too full or too little.
(3) After the filter is disassembled and maintained, reassembled and installed on the tractor, the air in it should be discharged.
2 The valve spring is not replaced for a long time
Due to the high temperature of the valve spring, it is easy to cause annealing if it is not replaced for a long time, so that its elasticity is insufficient. At the same time, because the valve spring is constantly subjected to alternating stress, long-term replacement will also produce plastic deformation, so that its free length is shortened and the elasticity is insufficient. The result of insufficient elasticity will inevitably lead to slow valve action and delayed closing, and it will also make the valve close loosely, resulting in insufficient cylinder pressure.
3 Neglect the maintenance of small holes
(1) Do not pay attention to the role of starting the spray hole. The carbon deposit in the starting nozzle is not removed for a long time, so that the nozzle is not smooth or blocked. The role of starting the jet hole is to enable diesel fuel to be directly injected into the cylinder through the jet hole earlier, and to first ignite and burn in the main combustion chamber to increase the temperature in the cylinder and improve the combustion conditions of the mixed gas in the main combustion chamber. Therefore, the starting nozzle is not smooth or blocked, will worsen the starting conditions, resulting in start-up difficulties.
(2) Oil tank cover vent hole. After the hole is blocked, the tank will no longer communicate with the atmosphere, and the upper part of the tank will have negative pressure due to the drop of the oil level, resulting in oil supply interruption; When the fuel evaporates after heating, the pressure in the tank will rise, which will cause oil leakage at the switch of the tank, therefore, this hole can not be blocked.
(3) crankcase stomata change. When the engine is working, there is always a certain amount of exhaust gas leaking into the crankcase through the piston ring. As the oil engine is used for a long time, with the wear of the cylinder liner piston ring, the gap increases, the piston ring elasticity decreases, and the exhaust gas leaking into the crankcase will be more. After the stoma is blocked, the exhaust gas in the crankcase will accumulate more and more, the pressure in the crankcase will increase, the oil will leak, the high-humidity exhaust gas will be mixed with the oil, it will also speed up the deterioration of the oil and accelerate the wear of the parts, therefore, we must dredge the hole when maintaining.
(4) Oil pump drain hole. The blockage of the drain hole on the oil delivery pump will cause a small amount of diesel oil between the push rod and the conduit to leak into the injection pump, dilute the lubricating oil in the housing, and accelerate the wear of the parts, so the hole can not be blocked.
(5) Water pump drain hole. If the hole is blocked, the leaking water can not drain out of the pump body and enter the bearing seat, which will accelerate the damage of the bearing, therefore, it is necessary to dredge the hole during maintenance.
(6) The oil jet hole on the cylinder cover is not dredged for a long time. Due to unclean oil and other reasons, it is easy to block the spray hole or not smooth, resulting in poor lubrication of the valve, valve guide, rocker arm and other parts, and wear too fast, resulting in lax valve closure, insufficient intake, unclean exhaust, power decline and other problems.
4 Valve clearance is not adjusted for a long time
When the engine is working, the valve and the valve transmission will expand due to the increase in temperature. If the engine does not use the hydraulic tappet, there is no gap or the gap is too small between the valve and the valve transmission in the cold state, the valve will be closed loosely in the hot state because of the thermal expansion of the valve and its transmission, causing the engine to leak in the compression and work stroke. Therefore, normal valve clearance is very necessary. The adjusted valve clearance will also become larger due to the wear and tear of the valve mechanism, which will reduce the valve lift, cause insufficient inflation, poor exhaust, and bring abnormal knocking sounds. Therefore, after the tractor is used for a period of time, the valve clearance should be checked and adjusted.
5 Cooling scale is not removed all year round
The scale is not removed all the year round will cause the scale is too thick, the body heat dissipation performance deteriorates, resulting in the machine temperature is too high, the oil becomes thin, deterioration, the mechanical strength of the parts decreases, and the early wear of the parts. At the same time, the intake air will be reduced and the power will be reduced. The expansion of parts is too large, affecting its normal technical performance, and in serious cases, there will be tile burning, shaft holding and other phenomena. To this end, before maintenance, fill the cooling system with a solution prepared in a ratio of 10 L water, 750 g caustic soda and 250 g kerosene, and leave the solution for 10 to 12 hours after the engine runs at a moderate speed for 5 to 10 minutes (note: In winter, heat preservation or continuous work to prevent freezing), then restart the engine to run at medium speed for 5 to 10 minutes, release the washing solution, and carefully rinse with clean water.
6 Neglect the maintenance of the oil filter
Engine lubrication is used for a period of time, which is mixed with metal chips and other mechanical impurities from the friction of engine parts and the gum produced by the oil itself. If these impurities enter the lubricating oil road with the oil, it will accelerate the wear of the engine parts, and may also block the oil pipe and oil passage. In order to prevent these impurities from entering the main oil passage, the engine oil path is equipped with an oil filter. The oil filter should be replaced once when the vehicle travels 7500 km, and for vehicles that often travel in poor road conditions, the oil condition should also be checked frequently, and the time limit for replacing the oil filter should be shortened if necessary.