Milling cutter is the main tool for mold processing, and its processing volume accounts for about 80% -90% of the total amount of mold cutting processing, thus becoming the focus of the development of mold processing tools. In recent years the development of some of the milling cutter new structure has been applied to more milling cutter products, some tool manufacturers into a series of milling cutter products using the new structure. For example, the milling cutter can slope away from the cutter, early for the processing of mold cavities or internal closed groove and development, it has a milling plane, milling cavity, milling holes and other functions, is very suitable for mold machining process is focused on the characteristics of the tool can be reduced to change the time.
Since the milling cutter is a cutting tool with large metal removal in cutting processing, improving milling processing efficiency has become one of the directions of milling cutter innovation. In order to help tool users overcome the difficulties brought about by the financial crisis, starting from the structural design of the tool, improving the economy of the tool has become one of the features of the current new product development of milling cutters. A commonly adopted practice is to design indexable inserts as double-sided available, doubling the cutting edge. At the same time, the economy of polygonal inserts can also be improved by increasing the number of edges.
In addition, it has been found that the use of titanium alloy as the cutter body material reduces the mass of the component and improves the rupture limit and limiting speed of the cutter. However, because of the sensitivity of titanium alloy to the kerf, it is not suitable for the manufacture of the cutter body, so some high-speed milling cutters have been used to manufacture the cutter body with high-strength aluminum alloy.
1. Reduce the quality of cutter, reduce the number of cutter components, simplify the cutter structure in the cutter body structure, should pay attention to avoid and reduce stress concentration, cutter body on the groove (including cutter seat groove, chip groove, keyway) will cause stress concentration, reduce the strength of the cutter body, so should try to avoid through the groove and groove bottom with sharp corners. At the same time, the structure of the cutter body should be symmetrical to the rotary axis so that the center of gravity passes through the axis of the milling cutter. The clamping and adjusting structure of the insert and cutter seat should eliminate the clearance as much as possible and require good repeatability of positioning. High-speed milling cutter has been widely used HSK shank and machine tool spindle connection, a greater degree of progress in the rigidity of the tool system and repeat positioning accuracy, is conducive to the progress of the tool rupture limit speed.
2. Improvement of tool clamping method simulation calculations and rupture test studies show that the clamping method of high-speed milling cutter inserts does not promise to use the usual friction clamping, to use the insert with a central hole, screw clamping method, or with a special design of the cutter structure in order to prevent the inserts from throwing off. Tool holder, blade clamping force direction is good with the direction of the centrifugal force, at the same time to control the preload of the screw, to prevent screws due to overload and early damage.
3.Progress in the dynamic balance of the tool to improve the dynamic balance of the tool to improve the safety of high-speed milling cutter has a great deal of help. As the unevenness of the tool will produce an additional radial load on the spindle system, the size of which is proportional to the square of the rotational speed. Let the mass of the rotating body be m, and the eccentricity between the center of mass and the center of the rotating body be e, then the inertial centrifugal force F caused by the amount of unevenness is: F=emω2=U (n/9549)2 where: U is the amount of unevenness of the tool system (g-mm), e is the amount of eccentricity of the center of mass of the tool system (mm), m is the mass of the tool system (kg), n is the rotational speed of the tool system (r/min), ω is the tool system angular velocity (rad/s). From the above formula, it can be seen that improving the dynamic balance of the tool can significantly reduce the centrifugal force and improve the safety of high-speed tools.
With the increasing popularization of the application of CNC machine tools, the traditional milling processing methods have been unable to meet the requirements of CNC milling, which greatly restricts the full play of the performance of CNC machine tools. Comprehensive and systematic introduction of modern milling new technology and practical application of knowledge for the promotion of modern milling processing technology progress and popularization of the application of milling processing technology to improve the milling process of technical efficiency and social and economic benefits has an important value, will certainly have a far-reaching impact.