Development and Trend of New Technology, New Structure and New Variety of Cutting Tool
With the rapid development of the manufacturing industry, the aviation industry and mold industry and other key industrial sectors continue to put forward higher requirements for cutting, and promote the use of new technology, new structure of the tool continues to emerge, and constantly enrich the variety of tools. Domestic and foreign tool manufacturers, such as Xiamen Jinlu Special Alloy Co., Ltd., in order to meet the requirements of aviation manufacturing tools, work closely with aviation manufacturing companies to develop new tools. Because aircraft parts have the characteristics of complex structure, high precision, thin wall parts and aircraft parts using titanium alloy, nickel-based alloy, carbon fiber and other difficult to process materials, it guides the development of aviation cutting tools in the following directions.
(1) High precision, high efficiency and high surface quality.
(2) Ultra-high precision and long life.
(3) High strength, high rigidity and other difficult processing materials.
(4) All kinds of metal materials and composite materials sandwich processing.
(5) the development of multi-functional tools and efficient special tools.
(6) the indexable tool is widely used. In the past, the overall cutting tools accounted for the vast majority in the processing of aviation materials. With the increase in the application of titanium alloys, high-temperature alloys and high-strength steels in aviation materials, the application of indexable cutting tools has also gradually increased. The indexable cutting tools have defects such as no welding and no cracks, giving full play to the cutting performance of the original blades, and reducing the auxiliary time for machine tool shutdown and tool loading and unloading, the use of indexable tools can improve the cutting efficiency by more than 35% than welding tools. At present, the indexable tools in western countries have entered the mature period, their varieties are increasing, the structure is optimized, and the geometric parameters are more reasonable. The share of cutting tools reaches about 8, and the use of less than 3 in our country. Therefore, for China's aviation industry parts processing, more extensive use of indexable tools is the future direction of development.
(7) the digitization of tool design and development. Modern cutting tools should not only meet the needs of advanced cutting technologies such as high-speed cutting, dry cutting, hard cutting, and composite cutting, but also meet the higher requirements of diversification of product functions, rationalization of structure, and practical appearance. However, the design of cutting tools in the past mainly relied on experience and experimental methods. This design method has low efficiency, long design cycle and difficulty in developing new products, obviously, it has hindered the development and use of new tools and cannot meet the needs of advanced cutting technology.
The development of modern cutting technology is an urgent need for advanced tool design technology, and tool design is characterized by difficult to calculate the spatial angle, complex shape, size and cutting mechanism is complex, but with the rapid development of computer technology and CAD/CAM technology, the use of advanced technology and special application software and tool simulation technology for tool research and development will become the future direction of tool design and development.
Development of new technologies related to cutting tools
The cutting of the tool depends not only on the tool itself, but also closely related to the use of machine tools, the connection between the tool and the machine tool, the tool handle system, the dynamic balance of the tool, the tool safety monitoring system, etc., and the technology related to the tool technology has also made new progress under the promotion of scientific and technological progress.
1. High speed cutting tool holder system
Machining centers and other CNC machine tools have been using the traditional 7:24 solid taper shank tool system, this tool holder due to the combination of only cone, the handle and spindle connection rigidity is low, the spindle speed of more than 10000r/min, the lack of connection rigidity is more obvious. For the use of ATC tool holder tool change, after each tool change, the radial size of the tool may change, there is a problem of low repeated positioning accuracy. In order to solve these problems, the standard 7:24 handle is mainly improved. Inspired by HSK handle, a new connection technology of 7:24 handle has appeared in recent years. For example, Japan's research company and Dazhao company have respectively developed two kinds of 7:24 connection handle with three contacts (3LOCKSYSTEM) and double-sided (BIGPLUS). Compared with the standard 7: 24 tool holder, they have higher connection rigidity and precision, can be used for high-speed and high-efficiency cutting, and can also be compatible with the existing 7: 24 tool holder or machine tool, which is the future development direction of 7: 24 tool holder. In addition to the transformation of the standard 7: 24 tool holder structure, the new HSK tool holder and KM tool holder are mainly used at present.
HSK tool holder is a new type of high-speed tapered tool holder. Its interface adopts the method of simultaneous positioning of cone surface and end surface. The tool holder is centered and the cone length is short, which is conducive to realizing the lightness and high speed of tool change. Due to the end surface positioning, the axial positioning error is completely eliminated, making high-speed and high-precision machining possible is also the development direction of tool manufacturing in our domestic manufacturers. The connection technology of high-speed tool and spindle will continue to develop with the progress of science and technology in the future, so that some new concepts-HSK, KM, 3LOCK, BIGPLUS and other tool handles have been further improved and perfected.
The current spindle and tool connection technology development direction is:
(1) Adopt double-sided positioning system;
(2) High clamping precision, good clamping rigidity and compact structure;
(3) the handle with balance and damping device;
(4) the development of multi-functional and intelligent handle.
2. Tool dynamic balance technology
There are also balance and safety problems for high-speed rotating tools. In the high-speed spindle system, the imbalance of any rotating body will generate centrifugal force. The centrifugal force generated by unbalanced tools or tool handles during high-speed cutting will cause machine tool vibration. The small imbalance of rotating tools will cause great centrifugal force during high-speed cutting. The irregular cutting force generated by unbalanced tools will lead to irregular wear, on the one hand, the result will affect the machining accuracy and surface quality of the workpiece, on the other hand, it will affect the service life of the spindle bearing and the tool, and more importantly, it will affect the safety of high-speed cutting, so high-speed cutting needs to be carefully balanced.
At present, foreign companies have developed special tool dynamic balance instrument and vertical tool dynamic balance instrument according to the requirements of tool dynamic balance, which can realize automatic tool dynamic balance measurement. The development direction of the new dynamic balance measuring instrument is accurate and efficient, easy to operate and powerful.
3. The development of tool edge passivation
At present, foreign imports of the whole tool or indexable blade cutting edge mostly carried out the edge of the passivation. After the passivation of the tool or blade edge micro-defects completely removed, effectively increasing the edge strength, the tool durability can generally increase 2 to times, most of the tools in China are not passivation treatment, low durability, tool consumption cost, so the tool edge of the passivation is a direction of the development of the current tool manufacturing in China.