Machinery is the general term for all kinds of constructione quipment used for construction. It is widely used in construction, water conservancy, power, roads, mines, ports and national defense. Engineering machinery remanufacturing is the object of waste engineering mechanical products. With advanced technology, the waste engineering machinery and equipment can be completely dismantled and renovated, and the production of remanufactured products which are completely equivalent to the new product performance and quality can be used to achieve efficient secondary utilization. A complete engineering machinery remanufacturing process can be divided into five stages:
1. Dismantling of engineering machinery
The first stage is the dismantling of engineering machinery, which is to disassemble the units of the engineering machinery into a single component. Disassembling is the first step process of engineering machinery remanufacturing, which directly affects the processing efficiency and the reutilization of the old parts. The traditional dismantling method lacks scientific and comprehensive evaluation, which is blindness and random, and this can result in time consuming, energy dissipation and power dissipation. The current scientific method is based on the drawing design and assembly process of the disassembled object, and combines with the corresponding disassembling tool and disassembling method, the technique of high efficiency non-destructive disassembling and the classification recovery technology are applied. It can effectively improve the recycling rate of the used parts, and achieve the goal of lossless, efficient and energy-saving, and improve the scale and automation of engineering machinery remanufacturing enterprises.
2. Cleaning of engineering machinery parts
The cleaning of waste parts of engineering machinery is an important part in the process of engineering machinery remanufacturing. The parts of the engineering machinery used in the process will produce all kinds of fouling, such as the outer surface of dust, sludge, the aging of the paint layer deterioration, lubricating oil of mechanical lubrication and fuel system and fuel dirt, metal surface corrosion. Therefore, it is necessary to clean the dismantled parts. The cleaning technology of baking oven, surface blasting, sand blasting, high pressure water jet, ultrasonic wave and so on can be used for non-destructive cleaning. It can also reduce the environmental impact of cleaning process and avoid secondary pollution. At present, foreign advanced remanufacturing enterprises have been able to clean physical (completely eliminate chemical cleaning), and the level of disassemble has reached zero emission completely. The application of the automatic ultrasonic cleaning technology, thermal expansion without deformation technology, non destructive shot peening cleaning technology and equipment without pollution, and high efficiency, wide application range, no damage to parts, it can significantly improve the emission standards for remanufacturing processes.
3. inspection and life evaluation of the parts of engineering machinery
The life assessment of engineering machinery remanufacturing includes two aspects: 1) assessment of the residual life of used parts. It answers the question of whether the old parts can be remanufactured and can be made for a few more times. 2) prediction of service life of remanufacturing parts (i.e. parts after manufacture). It determines whether the remanufactured parts are sufficient to sustain the service life of the next service cycle. Residual life assessment of used parts: the study on the residual life evaluation of metal magnetic memory technology for waste parts.
This technique is based on the magnetostrictive effect of ferromagnetic materials, which is characterized by magnetic domain structure and spontaneous magnetization in geomagnetic field environment. When the external force acts on the ferromagnetic material, it causes the change of the magnetic domain in the material, and the change will be "remembered" in the form of the leakage of the magnetic field, which remains after the external force is removed. Through the detection of "memory" content, the stress concentration and macro microcrack can be known to realize the early diagnosis and life evaluation of injury.
Using nondestructive testing techniques (such as eddy current testing, ultrasonic testing, X-ray detection, magnetic particle detection, etc.), combining the theories and techniques of mechanics and materials, and exploring the theory and method of nondestructive life assessment, and carrying out damage detection and life evaluation of parts. Over the years, a systematic study has been conducted on various nondestructive testing techniques: 1) non-destructive testing device (engine parts detection device, special pipe detection robot, etc.); 2) surface detection of parts (video, eddy current, magnetic memory, surface wave ultrasound, etc.); 3) internal detection of parts (ultrasonic, etc.); 4) analysis of residual stress of parts (x ray, metal magnetic memory, ultrasonic, etc.); 5) the status monitoring of service process of the remanufacturing parts (acoustic emission, etc.); 6) evaluation theory and method of damage degree of waste parts; 7) nondestructive evaluation theory and method of the quality of remanufacturing coating.
4. Repair and remanufacturing of the parts of engineering machinery
The repair and remanufacturing of engineering machinery parts is the core stage of engineering machinery remanufacturing. The waste parts are repaired and remanufactured, and the related tests and upgrades are carried out to meet the requirements. Surface engineering technology (including surface engineering technology and automation surface engineering) is the key technology of engineering machinery remanufacturing. Nanotechnology is one of the three high-tech technologies of the 21st century (information technology, nanotechnology, biotechnology). It will take 20 to 30 years for the application of the whole nano technology. At present, the dispersion of nanoparticles is distributed in the surface coating, so that nanometer materials are integrated with traditional surface engineering techniques, and the excellent effect of nanometer materials can be played. The technology of nano-surface engineering with independent intellectual property is developed in China. Specific technologies include: Nano - particle composite brush plating technology, nano-thermal spraying technology and nano - reduction and self-repairing additive technology. Nano - particle composite brush plating technology is used to further improve the coating effect by adding nanoparticles to the electroplating solution. It was developed based on the brush plating technology developed in the 1980s. It plays an important role in the repair and remanufacturing of failed parts. Nano-thermal spraying technology is based on the existing thermal spraying technology, and the new technology with nano-structure coating is obtained by spraying nano-structure particle powder or the silk material containing nano-structured particles. Nanometer anti-friction self-healing additive technology is a kind of friction chemical, on the surface of the friction surface, the solid state repair membrane which has the function of reducing friction and self-healing can achieve the dynamic balance of wear and repair. Thus, the technology of wear surface reduction and self-healing can be achieved without stopping or disintegrating. Engineering machinery remanufacturing process is the industrialization, the quantitative production process. In order to better adapt to the industrialization requirement of remanufacturing, surface engineering technology must be developed from manual operation to automation. Our country focuses on the development of automatic high speed arc spraying technology, automatic nano particle composite brush plating technology, semi-automatic micro-arc plasma cladding technology and automatic laser cladding technology, The performance and remanufacturing quality of the surface coating are further improved. Automatic high speed arc spraying technology is applicable to simple structure, wear and corrosion. And remanufacturing of parts that require higher efficiency. The automatic nano - particle composite brush plating technology is applied to the remanufacturing of parts with high damage and high degree of coordination. Semi-automatic microbeam plasma arc cladding technology is suitable for the complex structure and the remanufacturing of parts with high strength requirements. The automatic laser cladding technology is suitable for remanufacturing of parts with complicated structure, small size and requirements of metallurgy.
5. Assembly of the parts of engineering machinery
The fifth stage is to reassemble the repaired parts. The second optimization process should be carried out once the mismatch is found in the assembly process. The assembled products shall be tested to ensure the quality to meet the practical standard.
The leading brand of engineering machinery remanufacturing- Hunan Teila heavy industry technology co. LTD, it is committed to building the benchmark of China's engineering machinery remanufacturing industry and leading the industry.