Realize the repeatability that cutting machines

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  • source:KAIHER CNC Machining
To improve the treatment efficiency of the machine tool, with respect to the repeatability that must make sure cutting is machined. In addition, add what work efficiency leads to rise to depend on greatly the trends of the machine tool is characteristic. Rotate speed of denotive in plan of stable cutting district stable main shaft does not have flutter cutting deepness to depend on with what allow the natural frequency of whole treatment system, stiffness and damp. To most milling treatment, plan of stable cutting district announced to stabilize the interval limits of treatment, come true likely especially bigger cut deep main shaft rotate speed without flutter. Collet of cutting tool, cutting tool, main shaft, machine tool, workpiece and clamping apparatus can are opposite stable treatment interval produces an effect. Once used plan of stable cutting district to undertake optimizing to cutting craft, setting of change treatment parameter is met adverse to cutting function generation effect. However, have a lot of machine tool users but endowment the tool that use and skill (the aftertreatment that if the compensation of cutting tool length is adjusted,machines process designing with CNC) , can help the treatment parameter setting that has can rising machining repeatability. So, what influencing factor is crucial? Need to consider cutting tool length above all. Machine tool of CNC numerical control allows an user roughly length of set cutting tool, undertake metrical to this length, input pair of cutting tool length to undertake compensatory correction next. If the geometrical dimension of workpiece is most important, so compensation of this kind of dimension will be very effective. But, realize efficient treatment and depend on not just workpiece geometry dimension. If the cutting tool length of setting of user of a machine tool exceeded nominal measure, the stiffness of cutting tool can drop, and its natural frequency is taller also. So, pursue medium in stable cutting area, stability adds labour interval to be able to move to main shaft rotate speed smaller part, cut without flutter also meet greatly reduce subsequently. If the cutting tool length of the setting is shorter than nominal dimension, cutting tool stiffness can rise, natural frequency is taller also, interval of so stable treatment can move main shaft rotate speed more altitude. However, if stabilize treatment interval to did not move, of only possibility is to use in stability the biggest axial cuts the getatable inside treatment interval deep. Machine efficiency to rise, final user must control cutting tool length. The position that the tine number of cutting tool also can affect stability to machine main shaft rotate speed to pursue medium in stable cutting area. The stablest treatment interval appears in tooth with its through frequency natural frequency matchs each other place. Accordingly, e.g. , if change 2 blade milling cutter 4 blade milling cutter, can make correspondence reduces 50 % at the main shaft rotate speed of interval of the stablest treatment. If want to maintain from beginning to end,in stable treatment interval undertakes machining, mean want rigor to control main shaft rotate speed, accordingly, this also is meant should avoid to exceed ground of machine tool ability to use rotate speed of tall main shaft. Must choose proper main shaft rotate speed to enroll its machine program, and, main shaft must move with the rotate speed of process designing. The type of cutting tool collet is crucial also. The cutting tool collet of style of type of pinchcock head type, fluid pressure type, shrinkage fitting, Weldon side firm and other type has different dynamic character. Through adjusting work machine program, solve likely use new cutting tool collet and the problem of geometrical size variation that pose. But, change the position that cutting tool collet means rotate speed of stable main shaft will be mobile, and those who allow cut without flutter also meet greatly produce change. A few otherer the element effect to machining repeatability may be so not apparent. For example, when using collet of cutting tool of pinchcock head type, action may affect treatment repeatability at the torque on collet nut. Manufacturer of most bedspring collet is right the torque size on action Yu Luo's mother has restricted to set, and should use torque spanner or torque set clamping apparatus come set this torque. If this torque is too big, the stiffness of cutting tool collet may increase, but its damp can be reduced; If this torque is too small, collet stiffness can be reduced possibly -- more of flooey is, cutting tool is pulled likely a collet. On the problem of concerned torque, to ISO or collet of CAT cutting tool, action at taut sell the torque bulk that go up crucial also, also should use torque spanner to come set torque. If torque is too big, the fag end that will create cutting tool collet is bulgy, change collet and main shaft cone thereby cooperate, affect the tigidity of connection and damp directly. To the collet connection of ISO and HSK type, taut force is crucial also. Some people feel taut to force has been jumped over greatly more it seems that, but the fact is not such. Very great taut power can increase the stiffness of collet connection really, but it also can eliminate damp. Machine tool manufacturer set permission taut force range, use taut force dynamometer to detect taut force is a kind of good control way. Although cutting tool reachs his of collet choose the effect with have particularly main to cutting function, but be in a few otherer in influencing factor, the choice of machine tool and main shaft also nots allow to ignore to the influence of cutting function. The cutting function of different machine tool also each are not identical, although they use same cutting tool system. This is meant, should write work machine program in the light of particular machine tool, in order to use the figure of stable cutting area with this specific machine tool. To same cutting tool, its stabilize cutting district plan to look not identical on different machine tool. Now, software of numerical control process designing allows to consider the geometrical measure of workpiece only when writing work machine program. Undertake an aftertreatment to the program of the work out next, make its can move on all sorts of different machine tools. Use this to plant " consider geometrical measure only " process designing strategy is meant, the process capability of the machine tool has not get making full use of, can machine efficiency through rising substantially and benefit. CNC Milling