Easy maintenance of walking tractor
Author:Ricdro
The hand-held tractor is light and flexible, and it is a good helper for agricultural production. In order to improve production efficiency and extend the service life of the tractor, in addition to the usual operation according to the correct operation method, it is necessary to find faults and troubleshoot in time. Now let’s learn a bit, the diagnosis of common faults, and the knowledge of simple maintenance.
Expert introduction The walking tractor consists of engine, transmission system, braking system, walking system, electrical equipment and working equipment. We can simply divide into two parts: the engine and the chassis. Don’t look at its many parts, faults can be found by listening, watching, smelling, and touching.
First, the engine is difficult to start
Let’s take a look at how common faults in the engine are eliminated. Walking tractors generally feel that starting is difficult until they cannot start. The reasons for the difficulty in starting are: low ambient temperature, diesel problem, oily road failure, improper engine adjustment, low cylinder pressure, etc.
Ambient temperature is too low When the ambient temperature is below -15 degrees, the tractor is parked for too long and the engine is not easy to start when the engine is completely cooled. In this case, there are several ways to solve this. First, preheat the engine oil. Release the oil from the oil sump. heating. Then raise. Second, inject 90 to 95 degrees of hot water into the tank. After filling, open the water discharge switch on the cylinder to make it flow side by side. After the water temperature to be discharged reaches 30 to 40 degrees, the drain switch is turned off.
Diesel problem When the diesel fuel is not properly labeled, the viscosity is too large and it is not easy to flow, which will make the oil pump not suck into the oil, which makes starting difficult. The applicable seasons of several commonly used light diesel oils are: No. 0: National from April to September, winter in the south of the Yangtze River. No. 10: Winter in the south of the Great Wall and severe winter in the south of the Yangtze River. No. 20: North of the Great Wall and northwestern winter, south of the Great Wall and north of the Yellow River. No. 35: Northeast and northwestern winter. No. 50: Northeast, North China and Northwest China.
When the tractor has been in good condition, the engine is difficult to start with the newly filled diesel, indicating that the injected diesel is of poor quality, has impurities, or has moisture. Therefore, when adding diesel oil stored outdoors, it is best to let it stand for 48 hours to fully precipitate moisture and impurities before use. The diesel at the bottom of the tank is best used for other purposes.
The oil path is not connected. There is not enough diesel to enter the cylinder, and the engine is definitely starting to start. The reason is that the oil road is blocked. If the oil path is not available, first check if the fuel tank switch is open. Remove the dirt from the fuel tank cap and keep the vent or vent pipe clear. Loosen the bleed screw on the fuel injection pump. If there is air bubble in the oil flow, it means that the air enters the oil path, forming a gas resistance, which reduces or stops the fuel entering the cylinder, which makes starting difficult. Eliminate the air in the oil circuit. Tighten the tubing fittings. Check the seal at the diesel filter cover. When the fuel injection pump bleed screw is loosened and the crank pump oil is shaken, the resistance is large, and the oil at the bleed screw is small, which is blocked by the diesel filter. The diesel filter should be cleaned.
Improper engine adjustment After a period of engine use, vibration and wear, the technical parameters of the fuel injection pump change. These changes often cause difficulties in starting up. At this point, you need to re-adjust these parameters. When adjusting the fuel supply advance angle of the fuel injection pump, remove the high pressure pipe nut at one end of the fuel injection nozzle, and loosen the high pressure oil pipe nut at the other end so that the oil pipe is horizontally placed with the pipe port facing upward. Place the hand throttle in the oil supply position. Turn the flywheel. Fill the high pressure tubing with diesel. Then slowly turn the flywheel. When the nozzle oil level begins to rise, observe the oil supply line on the flywheel and align it with the score line on the water tank. The fuel supply advance angle should be 16 to 20 degrees.
If the line is ahead or behind, it should be adjusted. Adjust the method of increasing or decreasing the gasket in general. Add gaskets, delay oil supply, reduce gaskets, and supply oil in advance. Adjust until the reticle is aligned. Pay special attention when installing the fuel injection pump. The plug adjustment arm should be embedded in the speed control lever groove. this point is very important. The method of inspection is to pull out the oil dipstick and touch the adjustment arm with your finger. When the hand throttle is turned, the adjustment arm should swing with the throttle, otherwise it must be reinstalled.
Low cylinder pressure When the pressure reducing mechanism is not opened, the diesel engine crankshaft can be easily swayed, and there is a clear “puffing, breathing” sound in the intake and exhaust pipes, indicating that the valve is leaking. At this time, it is necessary to adjust the valve clearance. When adjusting, turn the flywheel so that the top dead center line on the flywheel aligns with the score line on the tank. Use a wrench and screwdriver to loosen the lock nut and adjustment screw on the rocker arm and insert the gauge between the valve and the rocker arm. Tighten the adjusting screw to adjust the intake valve clearance to 0.35 mm and the exhaust valve to 0.45 mm. Finally tighten the lock nut. Another cause of valve leakage is that the valve is not tightly closed. This kind of failure requires a repair station, a grinding valve and a valve seat. Another reason for the low cylinder pressure is the severe wear of the cylinder. The method of inspection is to add a small amount of lubricating oil to the snorkel. Then the car starts. If the pressure is increased, the piston ring or cylinder liner is seriously worn and the cylinder is poorly compressed. In the event of such a failure, it is also necessary to go to the repair station and replace the piston ring or cylinder liner.
Second, engine exhaust abnormalities
Black smoke from the engine When the mixture in the engine is not completely burned, black smoke is emitted. At this time, first reduce the load on the tractor. If the smoke color becomes lighter, the reason for the black smoke is that the load is too large and the load can be reduced. If the black smoke continues after the load is reduced, it is necessary to remove the dust from the air filter and remove the carbon deposits and oil in the exhaust pipe. If the air filter and exhaust pipe are cleaned, the engine still emits black smoke. Then check if the fuel injection timing of the fuel injection pump is too late. If it is too late, adjust the oil supply timing of the fuel injection pump. After adjusting the fuel supply timing, black smoke cannot be excluded, and the injector should be cleaned. When cleaning the injector, remove the injector to remove oil and carbon deposits around the nozzle. Screw the high pressure tubing to one side and install the injector. Shake the crankshaft and observe the fuel injection. If the oil is dripped, deflected, or not atomized, the injection pressure should be adjusted. When adjusting, remove the injector cap and use a screwdriver to turn the adjusting screw. Until the spray is in a normal mist, all the above methods are used, and the black smoke cannot be excluded. The cylinder is seriously worn, resulting in insufficient cylinder pressure. In this case, the piston ring or cylinder liner should be replaced at the repair station.
Blue smoke from the engine When the oil enters the combustion chamber, it will emit blue smoke. First check the amount of oil in the oil sump. If more than the upper limit is exceeded, excess oil should be released. Check the oil in the air filter sump. The amount of oil should not exceed the oil groove. If there is too much, the oil in the oil pan should be released. After the oil in the oil pan and the oil pan is normal, the blue smoke cannot be excluded. The engine is seriously worn. The engine should be repaired and the engine overhauled.
White smoke from the engine When there is water in the fuel or poor combustion, white smoke will be emitted. First release all the diesel in the tank. Check the water tank. If the cooling water is abnormally reduced at the same time, it may be that the cylinder is leaking. In case of such a situation, you should go to the repair station for further inspection. If there is no significant shortage of cooling water, add new diesel. Start the engine, empty low-speed warm car. After the engine temperature rises, increase the load and the white smoke will eliminate itself. We can also diagnose this way. If the white smoke discharged from the exhaust pipe is not continuous, but is one-and-one, indicating that the injector is dripping, the atomization is poor. The injector should be cleaned. If the white smoke discharged from the exhaust pipe is a large amount of continuous, and the power of the engine is significantly lowered, the exhaust gas temperature and the cooling water temperature are lowered. The injection pressure is insufficient and the needle valve is killed. The injection pressure should be adjusted.
Third, engine overheating
The performance of the engine overheating is that the cooling water in the water tank quickly boils. The engine is overheated and can be diagnosed and removed from the following aspects.
Water tank shortage Check the water tank. When the cooling water is insufficient, drive the tractor to a place with water supply and run at idle speed until the water temperature drops, then add cooling water. Cooling water should be added to the buoy to the highest position. Note that you cannot rush to add cold water when the engine is overheated to prevent the fuselage from rupturing. If the engine temperature is too high, it cannot be extinguished immediately, and the piston will not be killed in the cylinder. The water tank is not short of water, but when the engine temperature is too high, the debris in the outside of the tank, inside the tank and in the water jacket should be removed. When cleaning the outside of the tank, first wet the surface of the tank with water and then flush it forward from the back of the tank with a water pipe. For the clinging debris, it can be washed off with a brush. Do not use tools such as blades to harden them to avoid damaging the water tank. When cleaning the inside of the water tank and the water jacket, first release the old cooling water, fill the water tank with tap water, start the engine for 5 minutes, then release it, and the debris will be removed with the water. When there is too much scale deposit in the water jacket, the water tank is removed. Pour hydrochloric acid slowly into water, stir well, and prepare a 25% hydrochloric acid solution. The hydrochloric acid solution was poured into the inside of the water jacket and left for 10 minutes to dissolve the scale. The hydrochloric acid solution was discharged and washed with water. If there is too much scale, it can be washed several times.
If the oil supply is too late and the combustion chamber deposits carbon and add cooling water and cleaning the water tank, the problem of overheating of the engine cannot be ruled out. The oil supply advance angle should be checked and adjusted as described above. If the fuel supply advance angle is not faulty, the repair station should be removed to remove the carbon deposits in the combustion chamber.
Fourth, insufficient oil pressure
When the diesel engine is working normally, the indicator valve red mark should be raised. If the rise is not high, or does not rise, the oil pressure is insufficient. The diagnosis can be diagnosed from the following aspects.
Too little oil. Pull out the dipstick and check the oil. The oil level should be between the two engraved lines. If it is below the lower limit, make up the oil.
The oil is too thin. At the beginning of the engine start, the oil pressure is normal. However, after a while, the oil pressure will drop rapidly. Pull out the oil dipstick and the oil is normal. With your fingers, the viscosity is reduced. Look closely, the oil turns black, there are small drops of water, or you can smell the diesel. At this time, the oil must be changed. When replacing, heat the old oil and choose the same type of oil.
The oil filter is clogged. If there is no problem with the oil, check if the filter at the front of the oil pump is clogged. Remove the engine rear end cover when inspecting. Check if the filter is clogged. Clean the filter with clean diesel or kerosene. When cleaning, remove the spring ring from the filter cover, remove the filter, and clean the inside and outside of the filter. Install the oil filter in the reverse order.
Above we introduced the diagnosis and elimination of common engine faults. Next, we will introduce some troubleshooting and troubleshooting of common chassis failures.
Fifth, difficulties in hanging gear
Pull the clutch brake lever to the disengaged position. When the shift lever is pulled, it feels that the gear is struggling, or there is a gear striking sound when the gear is engaged, or the gear is not caught at all. The reasons and troubleshooting methods are as follows.
The clutch is not clear. The clutch is not clear. When troubleshooting, adjust the clutch clearance first. Put the clutch brake handle back into the engaged position. The thickness gauge is inserted between the split lever ball head and the release bearing. The gap should be 0.4 to 0.7 mm. The three gaps should be basically the same. If the gap does not meet the requirements, or the gap between the three gaps is large, it should be readjusted. The clutch clearance meets the requirements and the free travel of the clutch brake handle is checked. The free travel of the clutch brake handle should be 25 to 30 mm.
Adjust if the itinerary does not match and the requirements. Check if the shift lever tightening screw is loose. Tighten the shift lever connector and the nut on the shift lever pin. Check if the shift lever is deformed. If there is any deformation, it should be corrected and repaired.
Clutch bearing lack of oil When the clutch brake handle is pulled up, the release bearing emits a “sand, sand” abnormal sound, which is generally the lack of oil in the separation bearing. When refueling the separation bearing, first wipe the oil outside the bearing to make the bearing flexible. Then use a oil can to fill the bearing with oil. If the separation bearing cannot rotate, a metal friction sound is emitted when it comes into contact with the separation lever. When the clutch brake handle is released, the sound disappears, usually the bearing is ablated and damaged. Another cause of abnormal noise in the clutch is that the bolts on the clutch platen are loose or the inside of the clutch is damaged. In this case, you should go to the repair station to replace it.
Sixth, missing steering
The tires are not used for a long time, but the wear is more serious. Tire pressure should be checked, and too high and too low will accelerate tire wear. The standard value should be two kilograms per square centimeter. Inflate or deflate to bring the tire to the standard value. When the left and right tires are unevenly worn, they can be used interchangeably. When the tire needs to be replaced, the left and right tires are required to be replaced at the same time to ensure the uniform adhesion of the tires on both sides. But you must pay attention to the direction of the tire pattern. Seen from the front of the tractor, the pattern should be in the word “eight” or “person” and cannot be reversed. Frequently sticking diesel, oil, or other chemical solvents to the tires can exacerbate tire damage and keep the tread clean.
The steering lever is too long or too short. During driving, the steering handle is pulled up and the walking tractor cannot be turned or turned because the steering lever is too long or too short. The length of the steering rod should be checked and adjusted. The standard for the length of the steering rod is: grip the steering handle, when the distance between the steering handle and the plastic handle is 2 to 4 cm, the steering operation should be accurate. If the distance is too large, the steering rod should be lengthened. If the distance is too small, the steering rod should be shortened. Check for excessive wear on the steering arm hinge. If the wear is too large, it should be replaced. Check the steering fork journal and the inner hole of the steering cover for serious wear. If the wear is severe, it must be replaced.
Seventh, brake misalignment
Pulling the position backwards does not work as a brake, indicating that the brake is too late. When inspecting, pull the operating handle from the engaged position to the disengaged position. Hold the tractor, turn the tires, and the tires can rotate freely. Pull the operating handle from the disengaged position to the braking position. Tighten the tires hard, the tires should not rotate and brake firmly. If the above requirements are not met, loosen the lock nut. Turn the connecting fork on the lever. Then tighten the lock nut.
Above, we have studied the diagnosis and elimination of common faults in walking tractors. It is believed that through your efforts and practice, the walking tractor will be used correctly, low-cost and safely, so that the tractor plays a more active role in production.
