The cutting of cutting tools depends not only on the tool itself, but also on the use of machine tools, the connection between tools and machine tools, the tool handle system, the dynamic balance of tools, and the safety monitoring system of tools. The technology related to cutting tools has also made new progress with the advancement of science and technology.
1、 Tool holder system in high speed cutting
The traditional 7:24 solid taper handle tool system has been used in CNC machine tools such as machining center. Because the tool handle only depends on the cone surface, the connection rigidity between the tool handle and the spindle is low, and the spindle speed is more than 10000 R / min, so the lack of connection rigidity is more obvious. For tool change with ATC toolholder, the radial dimension of the tool may change after each tool change, which leads to the problem of low repeated positioning accuracy. In order to solve these problems, the standard 7:24 toolholder is improved. Inspired by HSK toolholder, a new 7:24 connection technology has appeared in recent years. For example, Japan Riyan company and dazhaohe company have developed two kinds of 7:24 connection toolholders, i.e. 3locksystem and bigplus. Compared with the standard 7:24 toolholder, they have higher connection rigidity and precision, can be used in high-speed cutting, and can also be compatible with the existing 7:24 toolholder or machine tool, which is the future development direction of 7:24 toolholder. In addition to reforming the structure of standard 7:24 toolholder, new HSK toolholder and KM toolholder are mainly used at present.
HSK toolholder is a new type of high-speed taper toolholder. The interface of HSK toolholder adopts the way of locating both conical surface and end face at the same time. The toolholder is centered and the cone length is short, which is conducive to realizing light and high-speed tool change. Due to the use of end face positioning, the axial positioning error is eliminated, making high-speed and high-precision machining possible, which is also the development direction of tool manufacturing in our domestic manufacturers. With the development of science and technology, the connection technology between high-speed tool and spindle will be developed continuously in the future. Some new concept toolholders such as HSK, km, 3lock and bigplus will be further improved and perfected. At present, the development direction of spindle and tool connection technology is as follows:
(1) Double sided positioning system is adopted;
(2) High clamping precision, good clamping rigidity and compact structure;
(3) The tool holder is equipped with balance and damping device;
(4) Develop multifunctional and intelligent toolholders.
2、 Tool dynamic balance technology
In the high-speed spindle system, the unbalance of any rotating body will produce centrifugal force. The centrifugal force produced by unbalanced cutter or handle in high-speed cutting makes the machine tool vibrate. The small unbalance of rotating tool will cause great centrifugal force and irregular cutting force caused by unbalanced tool On the one hand, it 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 cutter, and more importantly, the safety of high-speed cutting. Therefore, the dynamic balance of the cutting tool should be carefully carried out in high-speed cutting.
At present, foreign companies have developed a special tool dynamic balance instrument according to the requirements of tool dynamic balance. German HAIMER company and Italian cemb company have developed vertical tool dynamic balance instrument, which can realize automatic tool dynamic balance measurement. The development direction of new dynamic balance measuring instrument is accurate measurement, convenient operation and powerful function.
3、 Development of tool edge passivation
At present, most of the imported integral cutting tools or indexable inserts are passivated. After passivation, the micro defects of the tool or blade edge are removed, which effectively increases the edge strength, and the tool life can be increased by 20% to twice.