First, the change of maintenance concept 1, after-the-fact maintenance ideas In the early 20th century, construction machinery maintenance is generally carried out after the failure, that is, after-the-fact maintenance. Its greatest advantage is to make full use of the life of parts or system components, but after-the-fact maintenance is unplanned maintenance, wasting more residual repairs, but also has certain defects and deficiencies.

2, prevention-oriented maintenance ideas In the 1950s, people's understanding of the wear mechanism of the equipment has further deepened: the mechanical work - the occurrence of wear - failure - affects the use and endangers safety. In order for each machine to be reliable and safe to use, maintenance work must be carried out before the failure, thus forming a maintenance-oriented maintenance idea. This kind of maintenance thought contains the content of active prevention. The essence is to eliminate the fault in the bud by taking various preventive measures, and change the passive situation of lack of planning after the repair. However, this kind of maintenance thought also has certain limitations, mainly in three aspects: First, the maintenance work is guided by direct experience, and can only propose general maintenance principles, lack of pertinence; second, only focus on repairing The specific technical problems ignore the overall connotation of maintenance and lack of research on maintenance management. Due to the difficulty in predicting a large number of random failures in advance, it is difficult to obtain the expected results despite many preventive maintenance work. The third is the stereotyped repair and maintenance of the scheduled fixed-point maintenance, which inevitably causes maintenance. The phenomenon of frequent decomposition and disassembly of work leads to poor maintenance, heavy workload, time-consuming and high cost, and it may also bury some new hidden troubles due to disassembly and assembly, which greatly reduces the reliability of mechanical equipment.

3. Reliability-centered maintenance thoughts In the past two or three decades, on the basis of prevention-oriented maintenance ideas, modern management science has been used, and advanced testing techniques and diagnostic methods have been widely used to gradually form a reliability-centered Maintenance ideas. This maintenance idea is based on the system monitoring of the maintenance object, using a large number of in-situ detection instead of the off-site detection, and the maintenance of a single scheduled fixed-time maintenance change based on reliability data analysis. It makes the maintenance work more targeted, makes the subjective and objective more consistent, enhances scientificity, and reduces blindness. The basic points are as follows: 1 Maintenance work is based on reliability theory. The maintenance time, maintenance method, maintenance cycle selection and maintenance workload calculation, maintenance scope definition, the reliability coefficient after a machine repair, and the diagnostic criteria of a project must ensure and improve the equipment. Based on the overall reliability.

2 The reliability of engineering machinery is determined by three factors: design, manufacture and use. Therefore, to improve its reliability, we must start from these three aspects. Reliability repair maintains and restores mechanical performance and provides valuable data information for designing, manufacturing, and using units to increase the overall reliability of the equipment.

3 Reliability index is the most scientific and effective basis and standard for evaluating maintenance quality.

In summary, the reliability-centered maintenance idea follows the law of equipment failure, enhances the pertinence and flexibility of maintenance, improves the efficiency and efficiency of maintenance, and achieves the ultimate goal of maintenance work. total requirements.

Second, the status quo of the maintenance industry In foreign countries, industrialized developed countries pay more attention to the development of the maintenance industry, with a full-time maintenance management organization, maintenance companies in various forms, the maintenance market has become more mature, civil maintenance groups have more than 40 years of history, often hold maintenance The large-scale academic conference on equipment exhibition and maintenance theory and maintenance technology has effectively promoted the development of the maintenance industry. In the early 1970s, China's engineering machinery maintenance research and application entered a relatively fast development period, established scientific research institutions, academic groups, promoted the application of new equipment and new processes, and achieved certain results. At present, China's construction machinery maintenance industry is still not standardized, mainly in the following: First, the macro-management of the construction machinery maintenance industry lacks a unified centralized department. At present, the construction machinery maintenance industry is managed by several ministries such as the State Ministry and the administrative department of industry and commerce. The power is scattered and the responsibilities are unclear. It is difficult to coordinate and unify the policies, so that the management of China's maintenance industry is caught in a “vacuum zone”.

Second, there is a lack of laws and regulations to protect the normal development of the maintenance industry, resulting in the development of the maintenance industry can not be relied upon, no rules to follow.

Third, the nature of construction machinery maintenance enterprises is relatively simple, basically limited to the collective and private small and medium-sized maintenance enterprises, and the financing awareness is thin. Fourth, the competition, evaluation, supervision and incentive mechanism of the maintenance industry have not yet been established, the standards and systems are not perfect, and the evaluation of maintenance quality is unfounded.

III. Reform of the maintenance system It is envisaged that the reform of the maintenance system will affect the normal operation and healthy development of the maintenance industry. To make the maintenance of the construction machinery and the manufacturing industry coordinate development, it is necessary to construct an appropriate maintenance system. First, it is necessary to establish a management department with unified responsibility and responsibility as soon as possible, responsible for the macro-control of the construction machinery maintenance industry and planning its overall development. Second, we must increase the legislation and law enforcement of the industry, and formulate systematic and complete laws and regulations and standards so that the maintenance industry can rely on laws and evidence to accelerate the pace of development from administrative order to legal management. Third, actively create an external environment for the diversified development of the construction machinery maintenance industry. Formulate fiscal and tax incentives to support the development of the maintenance industry, rationally introduce foreign capital, increase mergers and restructuring efforts, and change the status quo of the relatively simple nature of maintenance enterprises.

Flexible and diversified management forms gradually form a joint venture, sole proprietorship, collective and private coexistence of competition and complement each other. Fourth, the construction machinery maintenance industry is encouraged to develop from professional separation to resource sharing. The modern equipment integrates mechanical, electronic, hydraulic, computer and sensor technologies, and puts forward higher requirements for maintenance. Maintenance companies that can only complete a single profession and type of work will face severe challenges. At the same time, repetitive investment will cause huge waste of resources. Enterprises with a small amount of maintenance resources can only adapt to the development trend if they realize resource sharing and complement each other. Fifth, the traditional fixed-point maintenance mode is transformed into a combination of fixed-point maintenance and mobile maintenance, and a professional patrol maintenance team is set up, equipped with high-performance mobile maintenance equipment to achieve on-site maintenance services.

Fourth, the development direction of the maintenance industry 1, based on state monitoring and fault diagnosis technology with the development of science and technology, especially the rapid development of microelectronics, computers, information technology, the application of opto-mechanical integration technology in engineering machinery Will be increasingly widespread. At present, the technology of condition monitoring and fault diagnosis has been greatly developed. Practice has shown that the more advanced the performance of engineering machinery, the more complex the structure, and the more its maintenance activities rely on the technology of condition monitoring and fault diagnosis. After-sales maintenance, preventive maintenance, and reliability-centered maintenance, each has its own length and scope. It is mechanically stipulated that a maintenance unit or a certain type of machine can only adopt a certain maintenance method, that is, it does not meet the requirements. Actually, it is difficult to work. At present, the maintenance of engineering machinery in developed countries is mainly based on condition monitoring, reliability maintenance as the center, combined with various maintenance methods, and different ways of maintenance according to different situations. In the future, with the wide application of condition monitoring and fault diagnosis technology, advanced engineering machinery will be equipped with mechatronics online automatic monitoring and fault diagnosis equipment, and reliability-centered maintenance ideas will become the leading mechanism of construction machinery maintenance management. thought.

2. Establish an intelligent network maintenance service system to build intelligence