Which industries and common functions are suitable for machining centers
Analyze the common functions of the four machining centers:
(1) Vertical machining center
The spindle of the vertical machining center is in the vertical position. It can complete the processes of milling, boring, drilling, tapping and thread cutting. The vertical machining center is at least three-axis two-linkage, generally can achieve three-axis three-linkage. Some can carry out five-axis and six-axis control, and the technicians can determine the processing range of the machining center according to the number of simultaneously controlled axes.
The height of the vertical machining center column is limited.When determining the range of motion of the Z axis, consider:
- ①The height of the workpiece;
- ②Height of tooling fixture;
- ③The length of the tool;
- ④ Space occupied by manipulator tool change.
After considering the above four situations, the machining range of the box-type workpieces of the vertical machining center should be reduced, which is the weakness of the vertical machining center. But the vertical machining center has the following advantages:
- ①Workpieces are easy to clamp, and the workpieces can be clamped with universal clamps such as flat-nose pliers, pressure plates, indexing heads, rotary tables, etc.The clamping and positioning of the workpieces are convenient;
- ②The tool movement track is easy to observe, the debugging program is convenient to check and measure, the problem can be found in time, and the shutdown process or modification can be performed;
- ③ Cooling conditions are easy to establish, the coolant can directly reach the tool and the machining surface;
- ④The coordinate system, that is, the three coordinate axes X, Y, and Z, coincides with the Cartesian coordinate system, and it feels intuitive and consistent with the drawing perspective;
- ⑤ Chips are easy to remove and drop, to avoid the chips from scratching the processed surface;
- ⑥ The structure generally adopts single-column type. Compared with the corresponding horizontal machining center, it has a simple structure, a small area and a low price.
Vertical machining center is most suitable for machining workpieces with relatively small dimensions in the Z axis direction. In general, except for the bottom surface, the other five surfaces can be contoured and surface processed with different tools.
(2) Horizontal machining center
The main axis of the horizontal machining center is set horizontally. The 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 lμm, and the positioning accuracy is 10μm— 20μm. The tool magazine capacity of horizontal machining centers 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 a larger volume and area, and a higher price. Horizontal machining center is more suitable for processing box parts. As long as it is clamped on the rotary table at one time, the four sides of the box (except the top and bottom surfaces) can be processed by milling, boring, drilling and tapping. In particular, some holes and cavities on the box parts have position tolerance requirements (such as the parallelism between the hole system, the perpendicularity of the hole and the end surface, the perpendicularity of the end surface and the bottom surface, etc.), as well as the holes and the cavity If there are strict dimensional accuracy requirements with the reference surface (bottom surface), it is easy to be guaranteed by one-time clamping processing on the horizontal machining center, which is suitable for the processing of batch workpieces. When debugging a horizontal machining center program, it is not as intuitive and easy to observe as a vertical machining center, and it is also inconvenient for inspection and measurement of workpieces, and the debugging time for processing procedures of complex parts is several times that of normal processing, so the more workpieces processed , The less time each machine tool takes up, so it is cost-effective to use the horizontal machining center for batch processing. However, it can achieve precision and quality requirements that are difficult to achieve with ordinary equipment, so some precision requirements are high, and other equipment cannot meet its precision requirements for workpieces, especially some spatial curved surfaces and complex-shaped workpieces, even single-piece production can be considered Processing on a horizontal machining center. It can be seen that the machining center is not only an efficient and high-quality automated production equipment, but also an equipment to overcome technological difficulties.
The coordinate system of horizontal machining center is different from the coordinate system of vertical machining center, that is, the three axes X, Y and Z in space. Moreover, the cooling conditions of the horizontal machining center are not as good as those of the vertical type, especially for deep hole boring, milling, drilling, etc., the coolant is difficult to reach the depth of the cutting, so the speed and feed of the machine tool must be reduced and the production efficiency is reduced . Compared with the vertical machining center, the horizontal machining center has many functions. 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 worktables of the horizontal machining center are numerically controlled and some are indexed. The workpiece can be processed in multiple stations by clamping at one time. Generally speaking, the horizontal machining center has its advantages and disadvantages.
(3) Multi-table machining center
Multi-table machining centers are sometimes called flexible machining cells (FMC). It has more than two replaceable worktables, and the processed workpieces can be moved out of the processing site together with the worktable (pallet) through the transport track, and then the worktable (pallet) with the workpiece to be processed is sent to the processing site. Multiple exchangeable worktables can be set to realize multi-table processing. The advantage is that it can realize online clamping, that is, at the same time of processing, the lower worktable can load and unload workpieces.In addition, the work pieces to be processed can be installed on other worktables.After the machine tool is started, this can be completed. For the automatic processing of batch workpieces, the workpieces on the worktable can be the same or different. This can be handled by the program. The multi-table machining center can be vertical or horizontal. No matter it is vertical or horizontal, its structure is more complex, the tool magazine capacity is larger, the machine tool covers a larger area, and the control system has more complete functions. Fast calculation speed and large memory capacity. All use the most advanced CNC system, so the price is expensive.
(4) Compound machining center
Compound machining center, also called multi-face machining center, refers to the equipment that can complete the processing of multiple surfaces after the workpiece is clamped at one time. The existing five-sided machining center can complete the processing of the five surfaces except the installation bottom surface after the workpiece is clamped once. This machining center has the functions of both vertical and horizontal machining centers, and can guarantee the positional tolerance of the workpiece during the machining process. The common five-sided machining center has two forms, one is that the main shaft is rotated or rotated at a corresponding angle, and it can become a vertical machining center or a horizontal machining center. The other is that the worktable rotates with the workpiece, and the main shaft realizes five-sided machining without changing the direction. No matter what kind of five-sided machining center has the disadvantages of complex structure and expensive cost.
Five-sided machining center has more functions than multi-table machining center, advanced control system, its price is about twice that of multi-station machining center with the same table size.
