In the daily use of agricultural machinery, wear, deformation, corrosion, etc. will occur. If the inspection of agricultural machinery is not carried out regularly, it will not only affect the work efficiency but also cause accidents. Therefore, the daily maintenance and repair of agricultural machinery is indispensable. And repair parts have many advantages such as saving materials, saving processing and 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. First, the classification of repair methods There are three basic methods for repairing agricultural machinery parts: restoration of size restoration techniques, repair-size repair techniques, and special repair techniques. Resilience repair techniques include welding and surfacing, thermal spraying, electroplating, electroless plating, spark coating and molten metal layers; repairing dimensions include machining, fitter, add-on method, partial replacement, transposition Etc. Special repair techniques include correction of deformation, surface strengthening, sealing and sealing, bonding and gluing, and pressure processing. At present, the repair techniques commonly used in production should be promoted and adopted with effective and advanced repair technology under economic and reasonable conditions in accordance with the principle of “mainly repairing and supplementingâ€. After the mechanical parts are damaged, there are many repair methods. In addition to the basic methods of machining (such as car, boring, planing, grinding, milling, etc.), there are also various process solutions, such as welding repair, repair, spraying, plating, Riveting, inserting, matching, modification, correction, expansion, compression, bonding, etc. The rapid development of science and technology has promoted the improvement of repair technology, and new science and technology has been widely applied to the repair process of mechanical parts. However, in the repair of specific parts, the structural characteristics, use requirements, working environment and other factors of the parts should be analyzed. According to the characteristics and application scope of different repair methods, technical and economic analysis is used to determine a more reasonable and economical repair process. Second, commonly used repair technology 1, welding repair. A variety of agricultural machinery parts made from commonly used materials can be repaired by welding. The failure modes of these parts are wear, breakage, cracks, pits, and the like. The advantages of the welding repair method are: the cover layer has high bonding strength with the original parts, the processing equipment is simple, the processing efficiency is high, the shape and size of the parts are not limited, and the cost is low. The main disadvantages are: the high temperature generated during welding may cause thermal stress changes in the metal structure, and cracks and deformation may occur. Commonly used welding methods are surfacing, welding and brazing. Surfacing is to cover a layer to several layers of material with performance requirements on the surface of the part. It not only repairs worn parts but also improves the wear resistance of the parts. Welding repair is often applied to large parts made of cast iron, such as cracks or defects in the body, re-manufacturing waste time and manpower and material resources. Welding repair is an effective repair method. Brazing is the heating of the solder material and the weldment to the melting point of the solder, and the solder is used to weld the part. 2, repair. Cracks in larger castings can be drilled at the end of the crack, preventing the crack from extending, and being reinforced with reinforcing plates to seal it (drilling and tapping around the broken part and repairing the nail to repair the larger crack) ,Broken hole) . This method is often used for the repair of body cracks. 3. Spraying. The metal wire is melted by thermal energy, and the molten metal droplet is blown with compressed air of 5-6 kg/cm to atomize the molten metal into particles having a diameter of 0.01 to 0.013 mm, and is 140 to 300 m/s. The velocity is sprayed onto the surface of the pre-prepared workpiece, and the particles are deformed by the impact, and after cooling, adhere to the surface of the part to form a sprayed layer. The use of electric arc to melt metal is called electric spraying; the acetylene flame is used to melt metal by gas spraying; and the high-frequency induction current is used to melt metal by high-frequency electric spraying. The spraying method has the advantages of simple equipment, convenient use, low production cost and wide application. 4. Plating. Apply a thin layer of chrome or other metal to the surface to restore the original size. Electroplating can improve the corrosion resistance, wear resistance and decorative appearance of the surface of the parts, and can also appropriately increase the geometrical dimensions of the parts, and has been widely used in agricultural machinery repair. Some important mechanical parts with high machining precision, such as gears and journals, are out of wear and are most suitable for electroplating repair. 5, riveting. After the relevant parts are loosened, they are repaired by riveting process to restore their normal working condition. 6, inlays. In the wear parts of the parts (such as journals, bores, etc.), a new metal sleeve is placed in a static fit to restore its original size. 7, matching. When the part or direction is worn out, if the structure allows, you can take the method of turning over, turning, etc. (such as the flywheel ring gear), flip the part or turn it to a certain angle, and replace the damaged part with the intact side. Continue to use the requirements. 8, modify. After the parts are worn, the dimensions are changed to achieve new geometric shapes and mating properties by boring, boring, sawing, expanding, and scraping. 9, correction. The plasticity of the metal material is utilized to restore the correct geometry of the part. The direction of the force or moment is consistent with the direction in which the deformation is required, such as pressure correction, tap correction, flame correction, and the like. It can be used to repair deformed parts such as crankshafts, connecting rods, and racks. 10. Swelling. Many hollow parts with simple shapes can be repaired if they are plastically swelled by cold expansion. 11, compression. With the pressure upsetting method, the outer diameter of the hollow and solid parts can be increased by reducing the height of the part. Reducing the inner diameter of the hollow part can be used to repair the outer or inner diameter of the non-ferrous metal sleeve. 12, bonding. The bonding repair method utilizes a bonding process of a chemical material, that is, a synthetic polymer compound, to form a chemical bond with a surface of a part to produce a large adhesive repairing part. In the repair of agricultural machinery parts, it is often used for the bonding of rupture parts and the adhesion of worn parts. Regular inspection and repair of agricultural machinery can effectively extend the service life while ensuring the safety of use. In addition, the application of agricultural machinery in agriculture is more and more widespread, and the popularity is getting higher and higher. The old machine repairing industry will also grow and provide jobs for more young people with technology. COVID-19 Antigen Rapid Test-nasophary Ngeal Swab-throat Swab Covid-19 Antigen Rapid Test-Nasophary Ngeal Swab-Throat Swab,Covid-19 Throat And Nasal Test Kit,Self-Test Covid-19 Antigen Test Kit,Covid-19 Antigen Saliva Test Weihai Kangzhou Biotechnology Engineering Co.,Ltd , https://www.weihaikangzhou.com
