Krympress reports:
Correct preseason preparation of combines is the basis of a successful harvesting campaign. According to statistics up to 85% of technical failures During field work, you can prevent qualitative diagnostics in the off -season. Every hour of downtime of the combine, in the midst of cleaning, turns into a harvest and fraught with deadlines. Therefore, mechanics should approach the maintenance systematically, checking all critical nodes according to a clear algorithm. A competently compiled checklist allows for full diagnostics for 12-16 working hours And to identify problems before their transition to the emergency stage.
Checking the power plant and transmission
The power plant is the heart of the combine, on which the performance of all systems depends. We begin diagnostics of the engine by checking the compression in the cylinders. For modern diesel engines normative values are 28-32 atmthe scatter between the cylinders should not exceed 2 atm.
It is important to remember: even a slight decrease in compression by 15-20% leads to an increase in fuel consumption by 8-12% and a decrease in engine power.
We check the condition of the air filter visually and measure the vacuum in the intake manifold. When clogging the filter by more than 80%, the vacuum exceeds 2.5 kPawhich requires immediate replacement of the element. The fuel filter is diagnosed by pressure at the entrance to the fuel pump-working pressure should be in the range of 0.2-0.4 MPa.
The analysis of the engine oil is carried out not only by color and consistency, but also with the help of express tests for the content of metal particles. The presence of iron is more than 75 mg/l or aluminum over 25 mg/l indicates the critical wear of engine parts.
We check the transmission step by step:
- Backlash in cardan compounds — no more than 1.5 °
- Tension of drive belts-a deflection of 10-15 mm with an increase in 40 N
- Terminating of the drive circuits — no more than 3% of the initial length
- Working pressure in the hydraulic system-16-20 MPa
Diagnosis of a threshing apparatus and cleaning system
The threshing device requires special attention, since it is here that the main technological process takes place. We check the drum for cracks and deformationsmeasure the gaps between the scourges and the deck. For a wheat threshing, the optimal clearance is 18-25 mm at the entrance and 8-12 mm at the output.
The condition of the drum bearings is critical — radial beating should not exceed 0.3 mm. Exceeding this parameter leads to uneven grinding and increased crushing of grain.
SoloProsas is diagnosed according to the following parameters:
- Gaps between keys and sieves-12-20 mm
- The condition of the keys of the keys — without bends and cracks
- The synchronism of the work of all sections is a deviation of not more than 2 °
We check the cleaning system comprehensively. We inspect the sieve for deformations and clogging of holes. We balance the fan dynamically — an imbalance of more than 50 g cm is unacceptable and leads to vibrations of the entire system. The fan blades should have the same installation angle with an accuracy of ± 1 °.
Proper tuning of the air flow is critical: at a wind speed of 8-12 m/s, high-quality cleaning of grain from light impurities is ensured.
Adjusting parameters for basic cultures:
- Wheat: Drum of the drum 600-800 rpm, deck of the deck 12-18 mm
- Barley: Drum of the drum 500-700 rpm, deck of the deck 15-20 mm
- Oats: Drum of the drum 400-600 rpm, deck of the deck 18-25 mm
Control of the harvesting part and screws
The harvesting part is subjected to the greatest loads during operation, therefore, it requires careful diagnosis. We check the cutting device according to the gaps between the segments of the knife and the contradictory plates — The working clearance is 0.5-1.0 mm. An increase in the gap to 2 mm leads to a low -quality section of the stems and tightening straw.
Motovilo is diagnosed according to several criteria. Graffin strips should be straightforward with a deviation of not more than 5 mm. We are checked by the MOTOVAVA for backlash-the permissible value in the gearbox does not exceed 8-10 angular minutes.
We pay special attention to the condition Shnecov combine. These nodes work in conditions of constant abrasive exposure and are subject to intensive wear. Diagnosis includes:
- Visual inspection of spiral turns for cracks and chips
- Checking the thickness of the edge of the turns-critical wear with a decrease to 3-4 mm
- Control of bearing nodes — radial play no more than 0.2 mm
- Checking the work of safety couplings at a load of 150-200% of the nominal
An inclined camera requires a chain conveyor check. We measure the chain stretching in a free area — permissible lengthening of not more than 2% of the initial length. We examine the stars for wear on the teeth — the depth of wear should not exceed 1.5 mm.
Professional Council: when worn by Schnections, more than 50% is more economically advisable to order new ones than spending time on recovery in the midst of the season.
Hydraulic system and control system
The hydraulic system provides management of all the working bodies of the combine. We begin diagnostics with checking the level and quality of the working fluid. The oil should be transparent, without metal inclusions and water emulsion. The operating temperature of the hydraulic system should not exceed 80 ° C at maximum load.
The main pump is tested by the developed pressure-the nominal value is 20-25 MPa depending on the combine model. The drop in pressure by more than 15% indicates the wear of plunger steam or valves.
We check the distributors for tightness and clarity of switching. Internal leaks should not exceed 3-5 l/min at working pressure. Hydro -cylinders are tested for the absence of leaks and smoothness without jerking.
Electronic control systems
Modern combines are equipped with complex electronic systems requiring a special approach to diagnosis:
- Calibration of yield sensors — Check with reference loads
- Testing of moisture sensors — comparison with laboratory data
- Diagnosis of GPS navigation — positioning accuracy ± 30 cm
- Checking the autopilot system — deviation from the course of not more than ± 2 cm
We check the lighting and signaling in accordance with the safety requirements. All headlights must provide Lighting at least 5 lux at a distance of 25 meters. The alarm is tested for visibility in the daytime at a distance of 150 meters.
Final verification and documentation
The final stage of training is a comprehensive testing of all systems. We carry out the trial launch in stages: first, idle for 30 minutes, then under load with a gradual increase in speed. We control the temperature regimes, pressure in systems and the lack of extraneous noise.
Important: all identified malfunctions should be Nenes before the start of field work. Attempts to “bring to the end of the season” lead to emergency situations at the most inopportune moment.
The final checklist should include marks about the readiness of each node with the signature of the responsible mechanic. It is recommended to conduct technical documentation in electronic form for operational analysis and planning.
Planning of spare parts for the season is a critical point. Statistics show that most often they fail Neds of the reapers, bearings and belts. For Schnecks repair It is advisable to prepare a set of turns and bearings in advance, since these works require time and special equipment.
Recommended schedule of repeated checks:
- After the first 50 hours of work — Control control
- Every 100 hours — checking adjustments and lubrication of nodes
- When changing cultures — Raster
- Weekly — Visual inspection of critical nodes
Correctly carried out preseason preparation — key trouble -free work of the combine Throughout the harvesting season. Investments in high -quality diagnostics are paid back many times by preventing downtime and preserving the crop.
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