With the rapid development of CNC machining center, the replaceable headstock machining center has appeared. It is equipped with a number of automatically replaceable multi axis headstock with cutting tools, which can process the workpiece at the same time. After decades of development, the current CNC lathe has achieved computer control and has been widely used in industry, especially in the mold manufacturing industry. Horizontal machining center generally has indexing turntable or numerical control turntable, which can process all sides of the workpiece; it can also make joint movement of multiple coordinates to process complex space surface. The vertical machining center generally does not have a turntable, only for the top surface processing. In addition, there are compound machining centers with vertical and horizontal spindles, and vertical and horizontal adjustable machining centers whose spindles can be adjusted into horizontal or vertical shafts. They can process five surfaces of the workpiece.
The automatic tool changing device of CNC machining center of milling machine is composed of tool magazine and tool changing mechanism. There are many kinds of tool magazine, including disc type and chain type. The storage capacity of chain magazine is large.
The tool change mechanism exchanges tools between the machine tool spindle and the tool magazine, commonly known as the manipulator; there are also no manipulator and the spindle directly exchanges tools with the tool magazine, known as the armless tool change device.
High precision and stable quality. It is processed according to the instruction given by the digital pattern. Under normal circumstances, there is no need for manual interference in the labor process, which eliminates the deviation caused by the dominator. When planning to manufacture CNC machine tools, many methods are adopted to make the parts of CNC machine tools reach higher accuracy and stiffness. The movement equivalent of CNC machine tool worktable is widely up to 0.01 ~ 0.0001mm, and the reverse clearance of feed transmission chain and screw pitch deviation can be compensated by CNC device. The high-grade CNC machine tool adopts the closed-loop control of grating ruler for worktable movement. The machining accuracy of CNC machine tool has improved from ± 0.01 mm to ± 0.005 mm or even higher. The positioning accuracy has reached ± 0.002mm to ± 0.005mm in the middle of 1990s. In addition, the transmission system and layout of CNC machine tools have high stiffness and thermal stability. By using the compensation technology, CNC machine tool can get higher machining accuracy than its own. In particular, the progress of a unified batch of parts production uniformity, product qualification rate is high, processing quality is stable. The selection of milling cutter diameter depends on different products and production batches, and the selection of cutter diameter mainly depends on the specifications of the equipment and the processing size of the workpiece.
Plane milling cutter
When selecting the diameter of the plane milling cutter, the power required by the cutter should be within the power range of the machine tool, and the diameter of the machine tool spindle can also be used as the basis for selection. The diameter of plane milling cutter can be selected according to d = 1.5D (D is the diameter of spindle). In batch production, the tool diameter can also be selected according to 1.6 times of the cutting width of the workpiece.
The selection of end mill diameter should mainly consider the requirements of workpiece processing size, and ensure that the power required by the tool is within the rated power range of the machine tool. If it is a small diameter end mill, we should mainly consider whether the maximum revolution of the machine tool can reach the minimum cutting speed of the tool (60m / min).
The diameter and width of the groove milling cutter should be selected according to the size of the workpiece to be machined, and the cutting power should be ensured within the allowable power range of the machine tool. Before using the CNC machine tool, you should read the manual of the machine tool and other relevant information carefully, so as to operate the machine tool correctly, and pay attention to the following points:
(1) The PLC program of the machine tool is designed by the machine tool manufacturer according to the needs of the machine tool, and does not need to be modified. Incorrect modification, operation of the machine tool may cause damage to the machine tool, or even injury to the operator;
(2) It is suggested that the machine can run continuously for up to 24 hours. If the continuous running time is too long, the service life of the electrical system and some mechanical components will be affected, which will affect the accuracy of the machine
(3) The operators and maintainers of machine tools must be professionals who have mastered the corresponding professional knowledge of machine tools or have received technical training, and must operate the machine tools according to the safety operation regulations and safety operation regulations