Machining centers are generally divided into three types
(1) VERTICAL MACHINING CENTER
The spindle of the vertical machining center is in a vertical position. It can complete milling, boring, drilling, tapping and cutting threads and other processes. The vertical machining center has at least three axes and two linkages, and generally three axes and three linkages can be realized. Some can carry out five-axis and six-axis control, and the craftsmen can determine the processing range of the machining center according to the number of axes they control at the same time.
The height of the column of the vertical machining center is limited. When determining the range of motion of the Z axis, consider:
① height of workpiece;
②The height of the fixture;
③The length of the tool;
④ The space occupied by the manipulator for tool change.
After considering the above four situations, the processing range of the vertical machining center for box-type workpieces should be reduced, which is the weakness of the vertical machining center. But the vertical machining center has the following advantages:
①The workpiece is easy to clamp, and the workpiece can be clamped by general-purpose fixtures such as flat-nose pliers, pressing plate, dividing head, rotary table, etc., and the clamping and positioning of the workpiece is convenient;
②The trajectory of the tool is easy to observe, the debugging program is easy to check and measure, and the problem can be found in time, and the machine can be stopped for processing or modification;
③The cooling conditions are easy to establish, and the coolant can directly reach the tool and the processing surface;
④ The coordinate system, that is, the three coordinate axes of X, Y, and Z, coincides with the Cartesian coordinate system, and the intuitive feeling is consistent with the perspective of the drawing;
⑤ Chips are easy to remove and fall off, avoiding chips scratching the processed surface;
⑥ The structure generally adopts a single-column type. Compared with the corresponding horizontal machining center, it has a simple structure, a smaller footprint, and a lower price.
The vertical machining center is most suitable for processing workpieces with relatively small dimensions in the Z-axis direction. Generally, except for the bottom surface, which cannot be processed, the other five surfaces can be processed by different tools for contour and surface processing.
(2) Horizontal machining center
The spindle of the horizontal machining center is set horizontally. A general horizontal machining center has three to five coordinate axes, often equipped with a rotary axis (or rotary workpiece table), the spindle speed is within 10-10000r/min, the minimum resolution is generally 1μm, and the positioning accuracy is 10μm— 20 μm. The tool magazine capacity of the horizontal machining center is generally large, and some tool magazines can store hundreds of tools. The structure of the horizontal machining center is more complicated than that of the vertical machining center, with larger volume and floor area, and higher price. Horizontal machining centers are more suitable for processing box-type parts. As long as it is clamped on the rotary table once, the four sides of the box (except the top and bottom) can be milled, bored, drilled, tapped and so on. Especially for some holes and cavities on box parts that have positional tolerance requirements (such as parallelism between hole systems, perpendicularity between holes and end surfaces, perpendicularity between end surfaces and bottom surfaces, etc.), and holes and cavities If there are strict dimensional accuracy requirements with the reference surface (bottom surface), it is easy to guarantee it through one-time clamping processing on the horizontal machining center, and is suitable for the processing of batch workpieces. When debugging the program of the horizontal machining center, it is not as intuitive and easy to observe as the vertical machining center, and it is also inconvenient for workpiece inspection and measurement, and the processing program debugging time for complex parts is several times that of normal processing, so the more workpieces processed , the less time each machine takes on average, so it is only cost-effective to use horizontal machining centers for batch processing. However, it can achieve precision and quality requirements that are difficult to achieve with ordinary equipment. Therefore, some workpieces with high precision requirements that cannot be met by other equipment, especially some workpieces with curved surfaces and complex shapes, can be considered even for single-piece production. Machining on a horizontal machining center. It can be seen that the machining center is not only an efficient and high-quality automatic production equipment, but also an equipment to overcome technological problems.
The coordinate system of the horizontal machining center is different from the coordinate system of the vertical machining center, that is, the three axes of X, Y, and Z in space. Moreover, the cooling condition of the horizontal machining center is not as good as that of the vertical one, especially for deep hole boring, milling, drilling, etc., it is difficult for the coolant to reach the depth of the cutting, so the speed and feed of the machine tool must be reduced, which reduces the production efficiency . Compared with the vertical machining center, the horizontal machining center has more functions, and the workpieces that cannot be processed on the vertical machining center can generally be processed on the horizontal machining center. In addition, some of the rotary tables of the horizontal machining center are numerically controlled, and some are indexed. The workpiece can be processed by multiple stations in one clamping. Generally speaking, the horizontal machining center has its advantages and disadvantages. When using it, use its advantages and avoid its disadvantages.
(3) Longmen processing center
The gantry machining center refers to the machining center whose spindle axis is perpendicular to the worktable. Among them, there are different styles such as fixed beam, moving beam, moving column, bridge type, etc. Users can make different choices according to product processing needs.
- Fixed beam type: (the beam is fixed and the workbench rotates). 2. Moving beam type: (the beam moves up and down, and the workbench moves back and forth). 3. Moving column type: (worktable is fixed, gantry moves). 4. Bridge type: (table is fixed, beam moves). There are also many types of gantry machining centers with the above composite forms, and the processing characteristics, functions, and product processing purposes are completely different.
Application features of gantry machining centers: heavy cutting, large sheet metal (such as plastic molds), large molds with high finish and other large-scale product processing and high-end molds, and large box structural parts. Application industry: large mold factory, large machinery factory.
The gantry machining center has the characteristics of one-time clamping, high-speed cutting, durability, low repair rate, high efficiency, low energy consumption, high precision, strong rigidity, stable performance, and large processing range, which can significantly improve processing efficiency. Measured and evaluated from the three aspects of stability, feasibility and economy, the gantry machining center has become the first choice in the machining industry
