Development mechanism and technical characteristic

2022-08-03
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The development mechanism and technical characteristics of modern cutting technology since the 1980s, cutting technology has achieved rapid development in industrial developed countries. By the end of the 20th century and the beginning of the 21st century, it has entered a new stage of "modern cutting technology" with high-speed cutting and high-efficiency cutting as the main technical characteristics. Looking back on history, cutting became a professional technology at the end of the 19th century and the beginning of the 20th century. It has gone through a whole century. Since the advent of cutting technology, it has been playing an important role as the basic process of manufacturing technology, and has made important contributions to the industrialization and economic development of industrialized countries. Although the cutting technology itself has made great progress in this process, it has not surpassed the scope of traditional cutting technology in general until the 1960s and 1970s. Its most prominent sign is that the development and production of cutting tools are basically separated from the use and users of cutting tools, and there is no mechanism of mutual promotion and common development

since the second half of the 20th century, due to the rapid development of emerging science and technology such as computer, microelectronics and material science closely related to cutting technology, cutting technology has also developed rapidly with the development of manufacturing industry and the progress of manufacturing technology, and has entered a new stage of modern cutting technology. Compared with traditional cutting technology, modern cutting technology not only embodies faster cutting speed and higher machining efficiency, but also forms a new development mechanism and mode, shows new technical characteristics, and becomes an important technical factor to promote the development of manufacturing industry and modern manufacturing technology

therefore, understanding and mastering the development mechanism, mode and technical characteristics of modern cutting technology is conducive to accelerating the development of cutting technology in China

development mechanism of modern cutting technology

for quite a long time after the advent of cutting technology, there is a problem that has always plagued the tool industry and tool users, that is, if you use expensive good tools for cutting, although it can improve the cutting efficiency, it will increase the manufacturing cost, and users think that the gains outweigh the losses. Therefore, many users are reluctant to spend more money to buy good knives, or worry that the knives will soon wear out after buying good knives, so the service life of the knives is set to be very long. These concepts and practices hinder the renewal of cutting tools, affect the enthusiasm of tool manufacturers to develop new tools, and restrict the improvement of cutting efficiency and the progress of cutting technology

a cost model of manufacturing economics reveals the internal relationship between the application of good tools and the reduction of manufacturing costs (Fig. 1). In this model, the manufacturing cost of parts is divided into tool cost, general management cost (indirect costs related to processing) and processing cost (machine tool usage cost, workers' wages, etc.), of which the tool cost only accounts for 3% ~ 4%, the general management cost accounts for about 25%, and the processing cost will be as high as 70%

Figure 1 manufacturing cost model

according to this cost ratio, the following conclusions can be drawn: if we passively pursue to reduce the tool cost, the result can only reduce a small percentage of the part manufacturing cost, such as reducing the tool cost by 50%, and the part manufacturing cost can only be reduced by about 2.5%, without considering the possible increase in downtime or cutting costs due to the use of cheap tools. If a good tool is used, although the tool cost may increase, because the cutting speed or feed rate can be increased - for example, by 20% - the processing cost accounting for 70% of the part manufacturing cost can be reduced by more than 10%, which is much higher than the 2.5% benefit generated by saving the tool cost. At present, the common saying in the cutting industry is that increasing the cutting speed or feed speed by 15% ~ 20% can reduce the manufacturing cost by 10% ~ 15%. Many cost analysis cases also show that although good tools are expensive, the tool cost allocated to each workpiece has not increased or even decreased due to the improvement of processing efficiency

the cost analysis model also tells us that when using good tools, if we do not pay attention to improving cutting efficiency but only pursue to prolong the tool life of carbon inert additives, we can only get very limited results in reducing manufacturing costs, and may even be counterproductive

based on similar manufacturing cost analysis models and the scale of the U.S. manufacturing industry, Swedish Sandvik company has made the following prediction: if the U.S. manufacturing industry promotes the application of cutting tools with better performance and generally increases the cutting speed by 20%, the annual processing cost can be saved by $15billion. The annual cost of cutting tools in the United States is about 3billion US dollars. If a third of the cutting tool investment is increased for this purpose, only 1billion US dollars will be spent. However, 15billion US dollars of benefits can be generated. It can be seen that the innovation of cutting tools can play the role of "pulling a thousand catties in four directions"

according to the situation in China, the China Metal Cutting Tool Technology Association of machinery industry proposed to carry out the "China Tool Association 20 project" nationwide in 2004, aiming to improve the cutting efficiency of China's mechanical processing by 20% through the joint efforts of talent training, modern cutting technology and the promotion of advanced tools, and the "production, learning, research and application" of the cutting industry. If the cost of cutting tools in China needs to be doubled, about 10billion yuan will be added to the cost of cutting tools. By improving the cutting efficiency by 20%, the country can save 80 ~ 100billion yuan in processing costs. At present, a few cases of enterprises have proved that it is possible to improve the cutting efficiency by 20% or more through efforts

at present, the internal relationship between improving cutting technology and creating considerable benefits for users and society revealed by the above model and a series of figures and cases has been recognized and accepted by more and more tool manufacturers and tool users, and has been transformed into a powerful driving force to promote the progress of cutting technology. In just 20 years or so, cutting technology has been pushed to a new stage of modern cutting technology

the current situation is as follows: on the one hand, the above cost model gives tool manufacturers great encouragement and establishes a new business philosophy of "innovating process, innovating tools, improving cutting efficiency and serving users", which injects new vitality into the traditional manufacturing technology of cutting and makes tool manufacturers become the main force in the development of modern cutting technology; On the other hand, this cost model has also been accepted by more and more tool users, forming a new thinking of "actively adopting new achievements of cutting technology, applying advanced cutting tools to improve machining efficiency, reduce manufacturing costs, and improve enterprise competitiveness", which has made the manufacturing industry pay unprecedented attention to and demand for advanced tools, and become a powerful force driving the rapid development of cutting technology. This "pull" is not a simple acceleration of the development of cutting technology, but gives a new development mechanism and power to the cutting technology, making it transition from the traditional cutting technology disconnected from the use to the new stage of modern cutting technology facing the needs of users and closely combined with the use

technical characteristics of modern cutting technology

cutting has entered a new stage of modern cutting technology, which is not only reflected in the fact that the development of cutting technology is based on the mechanism of interaction between tool manufacturers and tool users, but also shows the following obvious technical characteristics on this basis

(1) new cutting processes such as high-speed cutting, high-efficiency cutting, hard cutting and dry cutting have comprehensively broken through the technical barriers encountered by traditional cutting technologies in improving machining efficiency, and have changed the face of cutting processing as a whole.

these new processes have been applied to "big" cutting processing enterprises such as automobile, aviation, mold and equipment manufacturing, which not only doubled the machining efficiency, but also promoted product development and process innovation. For example, after the emergence of high-speed milling technology for aluminum alloy components in the aviation manufacturing industry, large aircraft structural components do not need to be assembled with components, but can be replaced with integral thin-walled aluminum alloy components, which not only reduces the component weight, increases the component strength and rigidity, but also improves the processing quality and reduces the manufacturing cost. The automobile industry, which is characterized by mass production, is a pioneer in the research, development and application of new cutting processes. It has developed many high-efficiency new processes for processing engine, gearbox and other major parts, greatly shortening the production cycle time. In recent years, the rapid development of the mold industry can be said to grow together with the efficient mold cutting process. The high-speed milling of large molds and the milling of hardened molds have changed the traditional mold processing process and greatly shortened the mold development cycle. In order to meet the needs of the rapid development of the mold industry, a new series of "mold tools" specially for mold processing has been formed, becoming the fastest-growing category of modern cutting tools

at the same time, the boundaries of traditional turning, milling, drilling and other cutting processes have been continuously broken, and some new cutting methods have emerged. For example, the newly introduced milling cutter can be used as a hole processing tool for drilling and reaming, which reduces the tool change time and improves the processing efficiency; Another example is the insert milling cutter that can efficiently remove the die cavity metal, the turning turning drawing process for machining the crankshaft, the milling turning process that replaces turning with milling on the compound turning center, and the high-speed thread machining process that uses carbide thread milling cutter instead of carbide tap, etc; Cutting technology continues to push through the old and bring forth the new, showing vigorous vitality and opening up new fields of manufacturing technology

in addition, with the development of various compound machine tools and the technology of "one machine tool or one clamping to complete all processing", the traditional concept of cutting processing will be further changed

(2) significant progress has been made in tool materials and coating technology, which has laid an important material foundation for the birth of modern cutting technology.

the practicality of high-speed cutting, high-efficiency cutting, hard cutting and dry cutting should first be attributed to the improvement of tool materials and the development of coating technology. The development of tool materials is reflected in the comprehensive progress of the properties of various tool materials, which improves the machining efficiency in all fields of machining. Especially, the progress of two kinds of tool materials, namely, the progress of superhard tool materials PCD, CBN and cemented carbide materials, should be emphasized

pcd and CBN materials have high hardness and particularly good wear resistance, and have been expected to become the promoters of high-speed cutting. However, due to their brittleness, the process of their application has been slow for quite a long time after their advent. In recent years, through the control and adjustment of the manufacturing process, formula composition, microstructure and particle size of PCD and CBN materials, the material toughness has been significantly improved, the variety has increased, and the application field has expanded, which makes the hope of using superhard tool materials for high-speed cutting a reality. PCD plays a unique advantage in high-speed and efficient machining of non-ferrous metals such as aluminum alloy, graphite, synthetic materials and other non-metallic materials; CBN also shows superior cutting performance in the high-speed machining of cast iron and the development and application of new hard cutting and dry cutting processes. The new CBN tools are not only used for the finishing of quenching hardware, but also for intermittent cutting and rough machining, which brings greater expectations for the new development of cutting technology

cemented carbide, as a tool material, also has the contradiction between hardness and toughness. Although its application in turning, milling, hole machining and other cutting processes has played an important role in improving the machining efficiency, the defect of poor toughness has not been significantly improved. Since the 1980s, the development of fine and ultra-fine cemented carbides has greatly improved the toughness of cemented carbides, so that the economy of the majority of users is gradually picking up to be used for making drill bits and erections

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