Introduction: with the more and more common use of agricultural machinery in the agricultural field, agricultural machinery will always be worn, deformed and corroded in daily use. If the agricultural machinery is not inspected regularly, it will not only affect the work efficiency, but also cause accidents. Therefore, it is very important for the daily maintenance of agricultural machinery.

 

Wear, deformation and corrosion will always occur in the daily use of agricultural machinery. If the agricultural machinery is not inspected regularly, it will not only affect the work efficiency, but also cause accidents.

Therefore, the daily maintenance of agricultural machinery is indispensable. Moreover, repair parts have many advantages, such as saving materials, saving processing, disassembly, adjustment, transportation and other costs, reducing maintenance costs, reducing the consumption of new spare parts, avoiding waiting for accessories, shortening downtime and so on.

1、 Classification of repair methods three basic methods can be adopted for the repair of agricultural machinery parts: repair technology of restoring size, repair technology according to repair size and special repair technology. The repair technology of restoring size includes welding and surfacing, thermal spraying, electroplating, electroless plating, electric spark covering and molten metal layer, etc; Repair technology according to repair size, including machining, fitter, additional parts method, local replacement method, transposition method, etc; Special repair technologies include correction of deformation, surface strengthening, sealing and plugging, bonding and patching, pressure processing, etc. At present, the repair technology commonly used in production should vigorously promote and adopt effective advanced repair technology under economic and reasonable conditions in accordance with the principle of "focusing on repair and supplemented by replacement". There are many repair methods for damaged mechanical parts. In addition to the basic methods of machining (such as turning, boring, planing, grinding, milling and other processes), there can also be a variety of process schemes, such as welding repair, repair, spraying, plating, riveting, bushing, selection, modification, correction, swelling, compression, bonding, etc. The rapid development of science and technology has promoted the improvement of repair technology. New science and technology has been widely used in the repair process of mechanical parts. However, in the repair of specific parts, we should analyze the structural characteristics, use requirements, working environment and other factors of the parts, and determine a more reasonable and economic repair process through technical and economic analysis according to the characteristics and scope of application of different repair methods. What if the parts of agricultural machinery are damaged? Teach you some ways to repair agricultural machinery!

2、 Common repair technology

1. Welding repair. The welding method can repair a variety of agricultural machinery parts made of common materials. The failure forms of these parts include wear, fracture, crack, pit and so on. The welding repair method has the advantages of high bonding strength between the covering layer and the original parts, simple processing equipment, high processing efficiency, unrestricted shape and size of parts and low cost. Its disadvantages mainly include: high temperature during welding may cause changes in metal structure, thermal stress, cracks and deformation. Common welding repair methods include surfacing, repair welding and brazing. Surfacing is to cover one to several layers of materials with performance requirements on the surface of parts by welding. It can not only repair worn parts, but also improve the wear resistance of parts. Welding repair is often applied to large parts made of cast iron. If there are cracks or defects in the body, remanufacturing wastes time, manpower and material resources. Welding repair is an effective repair method. Brazing is to heat the welding material and weldment to the melting point of solder and weld the parts with solder.

2. Repair. If a large casting has cracks, a unloading hole can be drilled at the end of the crack to prevent the crack from extending, and it shall be reinforced and repaired with a reinforcing plate to make it closed (drilling and tapping around the damaged part, and adding nails to repair the large cracks and holes). This method is often used to repair engine body cracks.

3. Spraying. Heat energy is used to melt the metal wire, and then 5 ~ 6 kg / cm compressed air is used to blow the molten metal droplets to atomize the molten metal into particles with a diameter of 0.01 ~ 0.013 mm, which are sprayed onto the prepared workpiece surface at a speed of 140 ~ 300 m / s. the particles are deformed due to impact, and then attached to the part surface to form a spraying layer after cooling. Melting metal with electric arc is called electric spraying; The process of melting metal with acetylene flame is called gas spraying; High frequency induction current is also used to melt metal, which is called high frequency electric spraying. The spraying method has the advantages of simple equipment, convenient use, low production cost and wide application.

4. Plating. A thin layer of chromium or other metal is plated on the surface of the parts to restore the original size. Electroplating can not only improve the corrosion resistance, wear resistance and decorative appearance of parts, but also appropriately increase the geometric size of parts. It has been widely used in the repair of agricultural machinery. Some important mechanical parts with high machining accuracy, such as gears and journal, are worn out, so electroplating repair is the most suitable.

5. Riveting. After the relevant parts are loose, they shall be repaired by riveting process to restore their normal working state.

6. Insert. A new metal sleeve is inserted into the worn parts of the parts (such as journal, inner hole, etc.) by means of static fit to restore its original size.

7. Optional. When part of the part or a certain direction is worn, if the structure allows, turn over, turn and other methods (such as flywheel ring gear) can be adopted to turn over or rotate the part at a certain angle to make its intact side replace the damaged part, so as to meet the requirements of continuous use. What if the parts of agricultural machinery are damaged? Teach you some ways to repair agricultural machinery!

8. Modification. After the parts are worn, their dimensions are changed by filing, chiseling, sawing, reaming, scraping and grinding, so as to achieve new geometry and matching properties.

9. Correction. Using the plastic characteristics of metal materials to restore the correct geometry of parts. The direction of force or torque is consistent with the required deformation direction, such as pressure correction, knock correction, flame correction, etc. It can be used to repair deformed parts, such as crankshaft, connecting rod, frame, etc.

10. Swell. Many hollow parts with simple shape can be repaired by cold expansion if the plasticity of the material is good.

11. Compression. By using pressure upsetting method, the outer diameter of hollow and solid parts can be increased because the height of parts is reduced. Reducing the inner diameter of hollow parts can be used to repair the outer diameter or inner diameter of non-ferrous metal sleeves.

12. Bonding. Bonding repair method is to use chemical materials, that is, the adhesive process of synthetic polymer compounds, to form a combination of chemical bonds with the surface of parts to produce greater bonding force to repair parts. In the repair of agricultural machinery parts, it is often used for the bonding of broken parts and the bonding of worn parts. Regular inspection and repair of agricultural machinery can effectively prolong the service life and ensure the safety of use. In addition, agricultural machinery is more and more widely used and popularized in agriculture. The agricultural machinery core repair industry will also grow and provide jobs for more young people with technology.

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