The cutting of the tool not only depends on the tool itself, but also closely related to the use of the machine tool, the connection between the tool and the machine tool, the tool handle system, the dynamic balance of the tool, the tool safety monitoring system and so on. and the technology related to the tool has also made new progress with the promotion of scientific and technological progress.
Tool shank system for high speed cutting.
CNC machine tools such as machining centers have always used the traditional 7:24 solid taper shank tool system. Because this kind of tool handle is combined only by taper, the connection rigidity between the handle and the spindle is low, and the rotation speed of the spindle exceeds 10000r/min, the deficiency of connection rigidity is more obvious. For tool changing with ATC handle, the radial size of the tool may change after each tool change, and there exists the problem of low repeated positioning accuracy. In order to solve these problems, the standard 7:24 knife handle is mainly improved. Inspired by the HSK shank, a new type of 7:24 shank connection technology has appeared in recent years, such as three contacts (3LOCKSYSTEM) and double-sided (BIGPLUS) 7:24 shank developed by Nippon Research Company of Japan and Showa Company of Japan respectively. Compared with the standard 7:24 shank, they have higher connection rigidity and precision, can be used for high-speed cutting, and are compatible with the existing 7:24 shank or machine tools, which is the future development direction of the 7:24 shank. In addition to reforming the structure of the standard 7:24 shank, new types of HSK shank and KM shank are mainly adopted at present.
The HSK shank is a new type of high-speed conical shank, whose interface adopts the way that the conical face and the end face are positioned at the same time, the shank is middle-fixed, and the cone length is short, which is beneficial to realize the lightweight and high-speed tool change. due to the use of end-face positioning, the axial positioning error is eliminated, which makes high-speed and high-precision machining possible is also the development direction of tool manufacturing in our domestic manufacturers. The connection technology between high-speed tool and spindle will be continuously developed with the progress of science and technology, which will further improve and perfect some new concept tool handles, such as HSK, KM, 3LOCK, BIGPLUS and so on. At present, the development direction of spindle and tool connection technology is:
(1) using double-sided positioning system.
(2) High clamping precision, good clamping rigidity and compact structure.
(3) tool handle with balance and damping device.
(4) develop multi-function and intelligent tool handle.
Second, 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 produce centrifugal force, and the centrifugal force produced by the unbalanced tool or handle during high-speed cutting makes the machine tool vibrate. the small unbalance of rotating tools will cause great centrifugal force in high-speed cutting, and the irregular cutting force caused by tool imbalance will lead to irregular wear. On the one hand, the results will affect the machining accuracy and surface quality of the workpiece, on the other hand, it will affect the service life of spindle bearings and cutting tools, and more importantly, the safety of high-speed cutting, so high-speed cutting needs to be carefully balanced.
At present, foreign companies have developed a special tool dynamic balancing instrument according to the requirements of tool dynamic balancing. HAIMER company in Germany and CEMB company in Italy have launched a vertical tool dynamic balancing instrument, which can realize automatic tool dynamic balance measurement. The development direction of the new dynamic balance measuring instrument is accurate measurement, convenient operation and powerful function.
Third, the development of tool edge passivation.
At present, most of the integral cutting tools or indexable blades imported from abroad have been passivated. The micro-defect removal of the passivated tool or blade edge effectively increases the edge strength, and the tool durability can generally be increased by 20% to twice as much.