The development trend of five-axis linkage machining center

Machining center

Five-axis linkage machining center has the characteristics of high efficiency, high precision, a workpiece clamping pentahedron processing can be completed. If match with five-axis linkage of high-grade CNC system, you can also to precision machining of complex curved surface, more can adapt to such as auto parts, aircraft structure of modern mold processing. Vertical five-axis machining center of the rotating shaft there are two ways, one is the workbench rotating shaft, set up on the bed of the workbench can surround the X axis rotation, defined as A shaft, A shaft generally work scope + 30 degrees to 120 degrees. In the middle of the table is equipped with a rotary table, in the position of graphic around the Z axis rotation, defined as C axis, C axis is 360 degrees of rotation. So through the combination of A shaft with C axis, fixed on the workbench artifact in addition to the bottom, the rest of the five surface can be processed by the vertical spindle. A shaft and minimum degree value is commonly 0.001 degrees C axis, like this can be subdivided into the workpiece at any Angle, processing of inclined plane, inclined holes, etc. Such as A shaft and C axis with XYZ three straight axis to realize linkage, can the space of machining complex curved surface, of course, the need of high-grade CNC system, servo system, and software support. This setting method has the advantage of the spindle structure is simpler, the spindle rigidity is very good, the manufacturing cost is low. But also general table design is not too large, the bearing is small, especially when A shaft rotation is greater than or equal to 90 degrees, the workpiece cutting the workbench when they bring A lot of load torque.

Another kind is rely on vertical spindle rotation of the head. Spindle front is A turret, can themselves around the Z axis 360 degrees, become C axis, and with A rotary head around the X axis rotation of A shaft, generally can reach more than plus or minus 90 degrees, realize the same function. Mode of this set has the advantage of the main shaft processing is very flexible, workbench can also design a very large, large airliner fuselage, huge casing can be in this kind of machining center. This design has a big advantage: we are using spherical milling cutter machining curved surface, when cutting tool processing center line perpendicular to the surface, as a result of the spherical milling cutter vertex linear velocity is zero, the vertices will cut the workpiece surface quality is very poor, adopts the design of spindle, the spindle relative to the workpiece around a point of view, the spherical milling cutter cutting, avoid the vertex ensure that there is a certain linear velocity, to improve the quality of surface processing. This structure is very popular with the high precision surface processing, this is the rotary table of machining center is difficult to achieve. In order to achieve high precision rotation, high-grade rotary shaft is configured with a circular grating ruler feedback, dividing accuracy within a few seconds, of course, this kind of spindle rotation structure is more complex, the manufacturing cost is higher also.

The development trend

1, the first is to use linear motor drive technology. After more than ten years of development, the linear motor technology is already very mature. Linear motor was developed are susceptible to interference and heat yield big problems have solutions, and linear motor positioning technology, both in the high-speed mobile quickly stopped, there is also a part of the machine tool manufacturers using damping technology solutions. Linear motor has the advantage of linear drive, no transmission chain, no wear, no reverse clearance, so can achieve the best positioning accuracy. Linear motor has high dynamics, the acceleration can be more than 2 g. Driven by linear motor has high reliability, free maintenance, etc.

2, the second is the double drive technology. For wider workbench or gantry type, if driven by the middle, actually cannot guarantee the driving force in the center, easy to cause tilt, make poor dynamic performance. Using double drive, two grating ruler, a driver module, can make the dynamic performance is very perfect. A driving instruction, double drive to work at the same time, the grating ruler to test whether two balance, if the imbalance through different instructions to make it reach to the balance. Of course, the development of five-axis linkage machine tool technology is far more than these, many of the techniques in DMG machine tools will be reflected in the product.

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