Strengthening the maintenance and repair of agricultural machinery to ensure its good technical condition is conducive to promoting energy conservation, emission reduction, safe production, and increasing farmers' income. It is of great significance for promoting the high-quality development of agricultural mechanization. To ensure the smooth progress of spring agricultural mechanization production, the following technical points for the maintenance and repair of tractors and supporting agricultural machinery have been compiled for reference by farmers.
1、 Inspection and maintenance of tractor engine
1. Check the lubrication system. In addition to replacing the three core (air filter, diesel filter, oil filter), it is also necessary to replace or clean each hydraulic oil filter. Lubricating oil and fuel should be replaced according to regional and seasonal requirements. If lubricating oil has already been released before the New Year, the oil filling port on the cylinder head should be opened, qualified lubricating oil should be added, and the oil level gauge should be checked after standing for ten minutes. The oil level gauge should be level with the "up" line of the oil level gauge, and then the oil level should be checked for 20-30 minutes. If there is an increase, it is necessary to investigate the cause and troubleshoot. If it is an engine with a turbocharger, it is necessary to remove the hollow bolt at the oil inlet of the turbocharger suspension bearing, drop a few drops of lubricating oil, and then reinstall it. Lubricating grease fittings and oil cups should be fully equipped. Each lubrication part and assembly should be filled with sufficient lubricating oil or grease according to the prescribed oil. The ventilator should be clean and unobstructed.
2. Check the cooling system. In cold regions, it is important to check whether the engine has frostbite, especially for vehicles that were not drained of water or antifreeze before the new year. Carefully inspect the engine body for signs of water blockage, drain switch, oil radiator, and other areas for signs of frost cracking. If it is normal, add soft water until the water tank mouth is level, let it stand for one hour, and see if the water level changes. If the water level drops, it is necessary to investigate the cause. If there is no decrease, it is normal. Be careful not to add well water and tap water that are prone to scale formation.
3. Check the circuit system. The circuits for starting, lighting, and instrumentation should be normal, and there should be no leakage, short circuit, or other phenomena in the insulation parts of all electrical accessories. The cold start device for engines in cold regions should be able to work properly. When the battery is low, it should be charged with one tenth of the rated current of the battery first. When charging lead-acid batteries, if the electrolyte level is level with the engraved line or 10-15 millimeters above the separator, the filling plug should be opened to prevent the air outlet from being blocked and the battery from exploding due to high air pressure. After charging is completed, the voltage of the individual battery should be around 13 volts. After all the above checks are normal, the main and auxiliary transmission handles should be in the "empty", "down", "middle" or "separated" position before starting; The hydraulic power unit should be in the "middle" position; At this point, you can open the small window on the flywheel housing, use a small pry bar to move the flywheel ring gear, rotate the crankshaft several times, and then turn on the ignition switch to start the power. The speed needs to be lowered first and then increased, gradually increasing the power speed. At the same time, observe the instrument and listen carefully for the sound. If there is any abnormality, stop the machine first and then check and eliminate the fault.
2、 Inspection and maintenance of tractor chassis
1. Check the lubricating oil. Check the lubricating oil of the gearbox, front axle, and end drive one by one; Check whether the lithium based grease (worm gear mechanical steering gear) or hydraulic oil tank (hydraulic steering gear) of the steering gear is sufficient; Check if the hydraulic oil in the hydraulic system is sufficient.
2. Check the steering system. Pay attention to the gap between the left and right directions, observe the clearance between the rod ball head transmission and the cylinder (hydraulic cylinder direction) pin shaft. If the clearance is too large, replace the rod ball head and cylinder pin shaft. After replacing the ball head and pin shaft, it is necessary to check the toe in. The toe in for four-wheel drive is 0-4 millimeters, and for two wheel drive it is 5-10 millimeters.
3. Check the clutch. Check the clearance between the clutch pedal, release bearing, and release lever to ensure thorough and flexible separation without any jamming. When stepping on the pedal for four fifths of the stroke, the gear shift can be engaged without any abnormal noise. If the clutch has been used for too long, it is necessary to disassemble and inspect the friction plate and release bearing. If it exceeds the limit, it needs to be replaced; If the wear is not significant, separate the bearing and add lubricating grease before assembling it according to the standard.
4. Check the brake. Check the brake fluid level and pedal travel. The first foot of the brake pedal should be able to be pressed firmly in one go, and the second foot should not move continuously. The return should be normal and there should be no jamming. The height of the left and right brake pedals should be synchronized.
3、 Coupling and adjustment of tractors and seeders
（1） Preparation and adjustment of tractor before broadcasting
The specifications of the transmission shaft and tractor PTO spline should match. Adjust the upper pull rod (center pull rod) and left and right lifting rods of the tractor to ensure that the seeder frame is horizontal in both longitudinal and transverse directions. Adjust the limit screw of the lower suspension arm of the tractor to ensure that the transverse centerline of the seeder coincides with the longitudinal centerline of the tractor. The pin shaft connecting the tractor suspension rod and the left and right suspension rods should be placed in the long hole position to achieve the overall imitation effect when the seeder is working. The hydraulic system distributor should be placed in the floating position during tractor operation. The mating length of the transmission shaft should not be less than 200 millimeters.
（2） Adjustment of seeder (taking air suction as an example)
1. Adjust the height of the rack. Before the sowing machine is officially operated in the field, the height of the sowing machine beam should be adjusted first, so as to leave a certain amount of upper contour for the contour mechanism on the sowing unit, avoiding damage to components or excessive sowing depth caused by the weight of the whole machine on the sowing unit. By rotating the supporting wheel adjustment screw to adjust the height of the supporting wheel, the seeding frame can be raised or lowered to ensure that the fertilization depth of the fertilizing components is appropriate.
2. Adjust the spacing between sowing rows. Adjust the row spacing of the seeder according to local agricultural requirements. When adjusting, use the centerline of the seeder beam frame as the reference line, and symmetrically move the seeding unit and fertilizer trenching components to the left and right. At the same time, the support wheel, transmission mechanism, and fertilizer discharge box should also be adjusted accordingly. The moved parts need to be tightened again.
3. Adjust the amount of fertilizer applied. The crop variety, number of seedlings per mu (ridge spacing and plant spacing), and soil fertility determine the amount of fertilizer applied per mu. According to the requirements of fertilizer application, the amount of fertilizer discharged by the fertilizer applicator is measured by rotating the support wheel 10 times, and then the amount of fertilizer discharged per mu is calculated (with a slip rate of 10%) until the fertilizer applicator is adjusted to achieve the amount of fertilizer discharged per mu.
4. Adjust the depth of fertilization. One method is to adjust the support wheels of the seeder to a certain height to adjust the depth of fertilization; Another method is to directly rotate the handle of the fertilizer opener and the pressure spring to adjust the depth of the fertilizer opener.
5. Replacement and adjustment of seeding discs. According to the sowing of different crops, different seeding discs should be replaced. The corresponding seeding discs should be replaced according to the instructions of the seeding device, and the corresponding components should be installed completely. After adjusting the seeding device, a trial run should be carried out to check whether each seeding device is operating normally.
6. Adjustment of sowing spacing. The adjustment of sowing distance refers to the adjustment of the transmission system of the seeder. Most seeder transmission systems are completed by chain transmission, which can be adjusted according to the sowing quantity table in the user manual. Hang the corresponding sprocket and tighten it.
7. Adjustment of sowing depth. Adjust the depth limit pointer handle on each sowing unit, and ensure that the depth limit indicator on each sowing unit is at the same scale position during operation to ensure consistent sowing depth of the whole machine. However, in the actual operation of sowing operations, due to differences in land preparation conditions and soil environment, the actual sowing depth should be measured after adjusting the sowing depth. Once there is a discrepancy between the indicated sowing depth and the actual sowing depth, a secondary adjustment should be made to achieve consistent sowing depth.
8. Adjust the fan belt. After checking whether the fan is firmly and safely connected and fixed to the seeding rack, check the tension of the fan belt. The belt tension should not be too loose or too tight. The operation method is to loosen the locking nut that fixes the large pulley, then adjust the length of the tension screw. When the belt tension is moderate, lock the adjusting screw with a nut, and finally tighten the locking nut that fixes the large pulley.
（3） Precautions for operating a seeding machine (taking air suction as an example)
1. Seeds and fertilizers should be loaded into seed boxes and fertilizer boxes after the unit arrives at the sowing site. If added before departure or field transfer, the weight of the seeder increases and the center of gravity of the entire unit shifts backwards, which is not conducive to transportation; At the same time, during transportation, the seeds and fertilizers will be compacted by vibration, which is not conducive to the uniform discharge of seeds and fertilizers. In addition, before packing, it is necessary to check whether there are any tools or other debris left inside the box.
Before the sowing machine is officially put into use, it needs to undergo trial sowing and debugging. When debugging sowing, always pay attention to the working condition of each component, observe the operation of each rotating component, check whether the transmission chain wheel and chain are running normally, whether the seed guide pipe and fertilizer discharge pipe are blocked, whether the fertilizer in the fertilizer box is in an overhead state, check the plant spacing, row spacing, and sowing depth of sowing, and finally adjust the relevant values to the agronomic requirements before normal sowing operation can be carried out.
Before starting the unit, the fan should be connected and the tractor should be operated with a high throttle. When the unit is turning in the field, the fan should reduce its speed and continue to operate to ensure that the seeds already adsorbed in the seeder do not fall and waste seeds.
4. When starting the seeder, it should be dropped while walking, and the seeder should not be forcefully placed into the soil to avoid damage to the working parts caused by severe impact, and also to avoid blockage of the seed guide pipe mouth and fertilizer trencher mouth.
5. The seeder should constantly monitor the various transmission components for any abnormal noise during operation. If any abnormalities are found, the machine should be stopped in a timely manner for inspection and troubleshooting before continuing operation.
6. The seeder is not allowed to make sharp turns or reverse during operation to avoid damaging the seeding components.
When the seeder is turning on the ground, it should be raised as high as possible, and the output shaft of the tractor should stop rotating to avoid damaging the seeding unit and the fan drive shaft.
When the seeder reaches the ground, the amount of seeds in the seed box and the amount of fertilizer in the fertilizer box should be checked. During the working process, the amount of seeds and fertilizer should not be less than 25% of the total capacity. If it is insufficient, it should be added in a timely manner.
After the sowing machine is debugged, it should be stopped for 3 hours to check whether the trenching components are deformed and whether the bolts are loose, to ensure that the sowing state is intact.
10. The input speed of the fan is 540 r/min, and the wheel bearings of the fan should be lubricated every 12 hours of operation to avoid bearing burnout due to lack of lubricating oil.
11. Attention should be paid to changes in sowing depth and sowing amount at all times, and adjustments should be made in a timely manner.