(1) vertical machining center
The spindle of the vertical machining center is in the vertical position. It can complete milling, boring, drilling, tapping and cutting threads and other processes. Vertical machining center at least three-axis linkage, the general can achieve three-axis triple linkage. Some can be five-axis, six-axis control, the process staff can control the number of axes at the same time to determine the processing center processing range.
Vertical machining center column height is limited, to determine the Z-axis range of motion to consider:
① the height of the workpiece;
② the height of fixture;
③ the length of the tool;
④ space occupied by the robot tool change.
After considering the above four cases, the vertical machining center to reduce the scope of processing of the workpiece category, which is the weakness of the vertical machining center. But the vertical machining center has the following advantages:
① easy to fit the workpiece, can be used common fixture such as flat pliers, platen, dividing head, rotary table and other fixture parts, the workpiece clamping easy positioning;
② tool movement trajectory easy to observe, debug the program to check the measurement is convenient, can be found in time to stop processing or modify;
③ cooling conditions easy to establish, coolant can directly reach the tool and processing surface;
④ coordinate system that is X, Y, Z three coordinate axes and Cartesian coordinate system, feel intuitive and consistent with the perspective of the drawings;
⑤ chip easy to remove and drop, to avoid the chip scratched the surface processed;
⑥ structure is generally a single column, it is compared with the corresponding horizontal machining center, simple structure, small footprint, lower prices.
The vertical machining center (Figure 5-1) is suitable for machining relatively small workpiece sizes in the Z-axis direction. In general, the bottom surface can not be machined, and the other five faces can be dimensioned and surface machined with different tools.
(2) Horizontal machining center
The spindle of the horizontal machining center is set horizontally. The horizontal machining center has three to five coordinate axes, often equipped with a rotary shaft (or rotary table), the spindle speed in the 10 ~ 10000r / min within the minimum resolution is generally lμm, positioning accuracy of 10μm- 20 μm. Horizontal machining center knife library capacity is generally large, and some knife library can store hundreds of tools. Horizontal machining center structure is more complex than the vertical processing center, volume and covers an area of large, the price is higher. Horizontal machining center is more suitable for processing box parts. As long as a clamping on the rotary table, you can box (except the top and bottom surface) of the four sides of the milling, boring, drilling, tapping and other processing. Especially for some of the holes on the box parts and the location of the cavity with the tolerance requirements (such as the parallelism between the hole, the hole and the end of the vertical, the distance between the end and the bottom, etc.), and the hole and cavity And the base surface (bottom) with strict dimensional accuracy requirements, in the horizontal machining center through a clamping process, easy to be guaranteed, suitable for batch processing of the workpiece.
(3) multi-table machining center
Multi-work center machining centers are sometimes referred to as flexible machining units (FMCs). It has two or more replaceable workstations, through the transport track can be finished with the work of the workpiece (tray) out of the processing site, and then put the workpiece to be processed workstations (pallet) sent to the processing site, this The exchangeable table can be set up to achieve multi-table work.
(4) composite processing center
Composite processing center, also known as multi-face machining center, refers to the workpiece after a clamping, to complete a number of surface processing equipment. The existing five-sided machining center, which in the workpiece after a clamping, can be completed in addition to the installation of the bottom surface of the five surface processing. This machining center has both vertical and horizontal machining center function, in the processing process can guarantee the workpiece position tolerance. Common five-sided machining center in two forms, one is the spindle to do or the corresponding angle of rotation, can be a vertical machining center or horizontal machining center. The other is the table with the workpiece to do the rotation, the spindle does not change the direction and achieve five-sided processing. No matter what kind of five-sided machining center there are complex structure, costly shortcomings.