How to evaluate the technical level of road constr

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How to evaluate the technical level of road construction and maintenance machinery

since the planned development of road construction and maintenance machinery in China began in the late 1960s, the industry has basically formed a scale at the time of loading. Although there is still a certain gap compared with developed industrial countries, it has been able to produce most of the products required for road construction and maintenance projects. At present, the lap joint should be made to pass through the force action center of the sensor. New models and technologies of road construction and maintenance machinery are constantly emerging, and the development, production and sales of products are very prosperous, which has entered a comprehensive development period

in recent years, the rapid development of China's high-grade highways, especially highways, has promoted the development of road construction and maintenance machinery to high-level, high-performance and large-scale special models. Some road construction and maintenance machinery with excellent performance have gradually entered the international market, marking that the technical level of China's road construction and maintenance machinery has jumped to a new level

however, it should be noted that the road construction and maintenance machinery industry in China has few types of machinery used for high-grade highway construction (such as asphalt concrete or cement concrete pavement pavers for high-grade highway construction, large-scale mixture drying and mixing machines and high-performance multi-functional maintenance machinery, which still need to be imported in whole or in large part), poor supporting capacity, backward manufacturing technology, low product comprehensive level, backward scientific research and development means The problems such as the imperfect means of detection and experiment are very prominent. In view of this, according to the current situation of China's road construction and maintenance machinery, it is of great significance to evaluate the product technology level of China's road construction and maintenance machinery, so as to have a more scientific and practical understanding of its product technology level, which is to catch up with and surpass the international advanced level and develop China's road construction and maintenance machinery according to local conditions. Generally speaking, this evaluation mainly includes the following aspects

service reliability

at present, China has no unified requirements for the service reliability of road construction and maintenance machinery. Foreign construction machinery products are generally required to be used continuously for 1500h ~ 2000h after leaving the factory without mechanical failure. According to the requirements of most manufacturers for the reliability of machinery, the continuous service life of such machinery in China should be guaranteed to be 1000h ~ 1500h without failure

the length of fault free period is the basic index to measure the reliability of machinery. Reliability not only reflects the internal quality of the machine itself and gives full play to its efficiency, but also is an important standard to reflect and measure the technology and management level of the manufacturer. In recent years, from the perspective of the world road construction and maintenance machinery industry, there are not many new models coming out, and most manufacturers are making articles in improving the technical level and reliability of machinery. According to recent statistics, caterpillar, one of the world's best construction machinery manufacturers, has adopted a large number of advanced technologies, such as laser leveling and infrared detection, to further improve the progressiveness and reliability of its products. From the overall level, the fault free time of continuous operation has exceeded 2400h. However, the self weight of similar machinery has increased in the same period. Most of the increased self weight is used to strengthen the strength and stiffness of weak parts of machinery. Their emphasis on mechanical reliability can be seen from this

due to the harsh working environment in which the road construction and maintenance machinery scratches the sheet metal carelessly, the reliability of its work is more important than the technical progressiveness of the machinery itself. Of course, the progressiveness of technology can also be used to improve the reliability of machinery. One of the important tasks of engineers and manufacturers is to find out their internal relationship and design the best arrangement

degree of self-control

the degree of self-control is the basic index reflecting the technical level of the machine itself. It refers to the degree of automation technology used by the machine in operations that cannot be completed manually and in work quality control

a typical example of automatic control is the hydraulic technology that emerged in the 20th century. Due to the installation of hydraulic torque converter (coupler), the driving torque of machinery can be automatically adjusted with the change of working resistance, so it has been widely used in earth moving machinery (such as full hydraulic loader and bulldozer) and military armored vehicles. In modern road building and maintenance machinery, the use of automatic control technology is also becoming more and more important, such as the use of automatic leveling devices in asphalt pavement (cement concrete pavement) pavers (the typical types are proportion pulse type and laser leveling type), the automatic weighing and control device of material proportioning used in mixture drum drying mixer, and the automatic manipulator of mechanical working process, etc. Their adoption greatly improves the construction accuracy of mechanical operation, improves the construction efficiency and quality, and reduces the operation intensity of operators. In recent years, the emergence of high-grade highways, especially expressways, in our country can not meet the construction quality requirements without automatic control of corresponding equipment with high-precision detection and quality requirements

automatic machinery fault alarm system also belongs to automatic control technology. It can not only find and repair machinery faults in time, but also has special significance for ensuring the personal safety of operators and construction site staff

it should be pointed out that the automatic control technology level of machinery is the concentrated embodiment of the scientific and technological development level of the whole country, and its development depends on the comprehensive level of multidisciplinary industries such as basic material industry, electronic industry, process design, machining and material heat treatment technology. Due to the low overall technical level in China, the automatic control technology of road construction and maintenance machinery is still in its infancy. However, from the perspective of development requirements, there is no doubt that the automatic control technology must be adopted and popularized as soon as possible

convenience of maintenance

convenience of maintenance depends on scientific and reasonable design and good processing technology. Any machinery, especially advanced high-tech machinery, will also have mechanical failures at any time. In order to improve the utilization rate, it is required that the mechanical failure should be handled on site. This requires the machine to have the reliable supply of vulnerable parts, the convenience of disassembly and assembly of parts and components, and the degree of universality and standardization of parts and components. At the same time, there should be special tools for the replacement of parts and components designed for specific machinery

it should be pointed out that the convenience of mechanical maintenance is closely related to its efficiency. Designers and manufacturers should regard it as an important indicator to improve product quality

operating and driving conditions

good operating and driving conditions mainly mean that the machinery should have comfortable riding conditions, broad vision and air conditioning and ventilation equipment. For road construction and maintenance machinery, due to its poor working environment, high mobility and extremely frequent operation, the driver is prone to fatigue, and it is also prone to operational errors and accidents. Therefore, having good operating conditions should be regarded as an important factor to improve work efficiency and reduce accidents

professional and technical training

any mechanical equipment, if the user does not know or knows little about it, will not only not give full play to its efficiency, but also damage the equipment, and in serious cases will lead to accidents. Statistics show that the road construction and maintenance machinery is operated by skilled operators and untrained operators. The occurrence rate of mechanical failure is 1:3, and the construction efficiency is 4:1. Therefore, whether to pay attention to professional training and hand over the use and maintenance knowledge and experience of machinery to users at the same time should also be regarded as one of the indicators to measure the technical level of machinery

China's road building and maintenance machinery manufacturers have begun to pay attention to strengthening the professional training of users. Many manufacturers have set up training centers in the factory for the advanced training of users, which has received good results. This is the experience gained from many trainings. The author has seen many failures caused by users' unfamiliar mechanical structure performance. In the construction of a key highway in Shanxi Province, in order to improve the construction quality and ensure the construction period, an asphalt pavement paver from a factory was purchased for construction. Due to lack of understanding of the mechanical structure and operating procedures, improper adjustment and lubrication, the main clutch malfunctioned as soon as it began to work. Had to ask the manufacturer to repair, delaying the construction period by nearly 20 days; Due to improper use of the large-scale drying mixer imported from Japan, the asphalt pump motor was quickly damaged and there were no replacement parts, which made the equipment unable to work in recent years. Such examples are numerous. Therefore, strengthening professional training should be regarded as a necessary work for manufacturers and management departments, and should be regarded as equally important as the reliability and high-tech level of machinery

the above five items to measure the technical level of road construction and maintenance machinery are very important. They are not only applicable to the selection of domestic machinery, but also applicable to the selection, negotiation and import of foreign machinery. Of course, with the development of science and technology and the improvement of highway grade, the technical level and working conditions of road construction and maintenance machinery will be expanded, and new models will continue to appear, The project indicators for measuring and evaluating the technical level of road construction and maintenance machinery will also be given new content

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