CNC machine tools include many types, such as machining centers, CNC lathes, CNC drilling machines, CNC milling machines, etc. These can be called CNC machine tools, and today’s machining center is also a type of CNC machine tool.
The machining center is a CNC machine tool with many functions. It integrates milling, drilling, twisting, boring, threading and thread milling. It has a variety of technical means and has strong comprehensive processing capabilities. Compared with ordinary machine tool processing, the machining center has many significant process characteristics.
The machining center can reduce the number of times the workpiece is clamped, eliminate positioning errors caused by multiple clamps, and improve machining accuracy. When the position accuracy of each processing part of the part is high, the processing center can be used to process each part in one clamping, which avoids the positioning error caused by multiple clamping of the workpiece and is beneficial to ensure the Position accuracy requirements.
At the same time, the machining center mostly uses semi-closed loop or even fully closed loop position compensation function, which has high positioning accuracy and repeated positioning accuracy. The dimensional errors generated during the machining process can be compensated in time, compared with ordinary machine tools. High dimensional accuracy. In addition, using a machining center can also reduce the auxiliary time for loading and unloading workpieces, save a lot of special and general process equipment, and reduce production costs.
Due to the good rigidity and high power of the machining center, it is necessary to use a larger amount of cutting as much as possible in the machining process, which can save processing time. However, the temperature rise generated under this condition will affect the machining accuracy of the parts, so it is necessary to select the appropriate tool and fixture, and pay attention to adequate cooling.
Reasonably arrange the processing procedures and determine the processing procedures of the parts
Determine the machining base surface, reference hole, machining allowance, etc. of the part. The final accuracy requirements and heat treatment requirements of the parts should be considered when determining the content of the process completed in one clamping. For some complex parts, due to thermal deformation, internal stress, part compression deformation and other reasons generated during the processing, they have to be clamped twice or more to complete the processing.
The processing sequence should be in accordance with the principle of roughening and gradually finishing, that is, heavy cutting, roughing, but removing most of the machining allowance on the blank of the part, and then arranging the machining process with small calorific value and low processing requirements, so that the parts are refined There is sufficient time for cooling before processing, and finally finishing. Each process should minimize the amount of empty travel and reduce the number of tool changes. The recommended processing sequence is: milling a large plane / (rough and fine separation /)-rough boring, blue precision boring-end milling, machining a dozen centers, drilling a hole, drilling a thread, and finishing holes (Stranding, boring, precision milling, etc.).