One is the turntable shaft.The table placed on the bed can rotate around the X axis, defined as the A axis, and the A axis usually works in the range of 30 degrees to -120 degrees. There is also a turntable at the center of the watch, which is defined as the axis C and the axis C being 360 degrees when rotating around the Z axis at the position shown. In this way, through the combination of axis A and axis C, the parts fixed on the table can be processed by the vertical spindle, except for the lower surface. The values of the minimum index axis A and axis C are usually 0.001 degrees, so that the workpiece can be divided into arbitrary angles, and can be processed oblique holes, inclined surfaces. If axes A and C are linked with three linear axes XYZ, complex spatial surfaces can be processed. Of course, this requires a servo system and high-end software. The advantage of this arrangement is that the structure of the main shaft is relatively simple, the rigidity of the main shaft is very good, and the manufacturing cost is relatively low. However, the general workbench cannot be designed too large, and the weight supported by the load is also very small. Especially when the axis A rotates greater than or equal to 90 degrees, the workpiece will bring a large rolling torque to the table when cutting.
The other is the rotation of the vertical spindle head.
The front end of the shaft is a turntable, which can be wound 360 degrees to rotate around the Z axis as the axis C. It also has an axis A, which can be rotated around the axis X, generally up to ±90 degrees, for achieving the same function. The advantage of this structure is that the machining spindle is very flexible, the worktable can also be designed very large, and the huge motor housing can be processed in such a machining center. This design also has a great advantage when the surface is processed by ball milling with a cutting machine. When the center line of the tool is perpendicular to the processing surface, the surface quality of the workpiece cut by the apex will be deteriorated due to the linear velocity of the top line of the zero point of the spherical milling cutter . The design of the rotation of the main shaft makes the rotation of the mandrel relative to the workpiece through the angle, so that the cutting ball mill avoids cutting the apex, ensuring linear velocity and improved quality surface treatment. This structure is very popular in the processing of high-precision surface molds, which is difficult to achieve in the rotary machining center of the worktable. In order to achieve high rotation accuracy, the high-end rotation axis is also equipped with a circular scale feedback, and the indexing accuracy is a few seconds. Of course, the rotation structure of such a shaft is complicated, and the manufacturing cost is also high.
Five-axis machining vertical machining center can carry out high-quality precision and high surface precision parts to meet the special requirements of aerospace automobiles, special materials industry, thin-walled parts and high illuminance accuracy. Get high-speed machining, not just provide suitable high-speed CNC machine tools. At the same time, there must be a corresponding tool holder tool to be effective. The five-axis vertical machining center not only solves the problem of complex mold processing, but also provides a solution for the processing of complex structural parts. Five-axis machining centers are much more expensive than three-axis general-purpose machine tools. For those machines that require four-axis machining, the user can add a rotary table to achieve this goal. You don’t need to buy a five-axis machine at a favorable price, you can save money. .
Three-way vertical machining center, five-axis for spindle rotation.
The gravity of the spindle of the vertical machining center drops, the radial force of the high-speed air bearing is equal, and the rotation characteristics are very good, so the speed can be increased. In general, high speed can reach 1.2000r/min or higher, and Zui’s actual high speed has reached 40,000rpm. The spindle system is equipped with a circulating cooling device. The cooling oil in the circulation eliminates the heat generated by high-speed rotation, cools to a suitable temperature through the refrigerator, and then returns to the spindle system. The three linear axes X, Y, and Z can also be linear encoder feedback, and the bidirectional positioning accuracy is within the micron level. Due to the rapid travel of 40 to 60 meters/minute or higher, the X-axis, Y, Z ball screws mainly use central cooling. As with the spindle system, circulating oil circulates through the center of the spindle to remove heat.
Five-axis horizontal machining center.
There are two ways to rotate the axis of this type of machining center: one is the rotation of the horizontal main shaft as the rotation axis, and the rotation axis of the table is used to perform five-axis linkage processing. This configuration is simple and flexible. For example, if you need to convert the axis to, you can simply configure the table as a three-axis machining center, horizontal conversion to the horizontal conversion of the spindle and the index of the worktable, the processing of the pentahedron of the workpiece, the manufacturing cost is reduced and it is very practical. You can also set the CNC axis of the worktable, and the small division value of the zui is 0.001 degrees, but there is no link. It becomes a four-axis machining center for vertical and horizontal conversion. It is suitable for different processing requirements and the price is very competitive.
The other is the traditional table rotation axis. The work axis of table A placed in the bed usually has a working range of 20 degrees to -100 degrees. There is also a B-axis turntable in the center of the table, which can rotate 360 degrees in two directions. This five-axis horizontal machining center has better than the connecting rod characteristics, and is usually used to process the complex surface of large impellers. The rotary axis can also be configured with feedback from a circular encoder, and the indexing accuracy reaches a few seconds. Of course, the structure of the rotating shaft is complicated and expensive.