Structural composition of machining center

Structural composition of machining center.

With the vigorous development of machining centers, various types of machining centers have appeared in countries around the world. Although their appearances and structures vary, they are generally composed of the following parts.

(1) Basic components

It consists of large parts such as the bed, column and workbench. It is the basic component of the CNC machining center. Since it has to bear the static load of the CNC machining center and the cutting load during machining, high-quality cast iron parts are generally selected.

(2) Spindle assembly

It consists of parts such as the spindle box, spindle motor, spindle and spindle bearing. Its start, stop and rotation are all controlled by the CNC system, and it participates in the cutting movement through the tool installed on the spindle. It is the power output component of the cutting process. The spindle is a key component of the CNC machining center, and its structural quality has a great influence on the performance of the CNC machining center.

(3) Servo system

The function of the servo system is to convert the signal from the CNC device into the movement of the moving parts of the machine tool. Its performance is one of the main factors determining the machining accuracy, surface quality and production efficiency of the machine tool. CNC machining centers generally use three control methods: semi-closed loop, closed loop and mixed loop.

(4) Control system

The CNC part of a single CNC machining center is composed of a programmable controller, a servo drive device and a motor. They are the control centers for CNC machining centers to execute sequential control actions and complete the machining process.

(5) Automatic tool changer (ATC)

It consists of tool magazine, manipulator and drive mechanism. Tool magazine is a device for storing all the tools used in the machining process. Commonly used are bamboo hat and disc tool magazines. When the tool needs to be changed, according to the instructions of the CNC system, the manipulator (or other ways) is extended to take the tool out of the tool magazine and load it into the spindle. Some CNC machining centers do not use manipulators but use the movement of the spindle box or tool magazine to achieve tool change. Although the tool change process, tool selection method, tool magazine structure, and manipulator type are different, they are all controlled by the CNC device and programmable controller, and the motor and hydraulic or pneumatic mechanism drive the tool magazine and manipulator to achieve tool selection and exchange.

(6) APC automatic pallet exchange system

In order to further shorten the non-cutting time, some CNC machining centers are equipped with two automatic exchange workpiece pallets, one installed on the workbench for processing, and the other located outside the workbench for loading and unloading workpieces. When the workpiece on a pallet is processed, the pallet is automatically exchanged to process the new part, which can reduce auxiliary time and improve processing efficiency.

(7) Auxiliary system

It includes lubrication, cooling, chip removal, protection, hydraulic and random detection systems. Although the auxiliary system does not directly participate in the cutting movement, it plays a protective role in the processing efficiency, processing accuracy and excellence of the CNC machining center. Therefore, it is also an excellent part of the CNC machining center.